linux/arch/x86/kvm/x86.c

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/*
* Kernel-based Virtual Machine driver for Linux
*
* derived from drivers/kvm/kvm_main.c
*
* Copyright (C) 2006 Qumranet, Inc.
* Copyright (C) 2008 Qumranet, Inc.
* Copyright IBM Corporation, 2008
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* Authors:
* Avi Kivity <avi@qumranet.com>
* Yaniv Kamay <yaniv@qumranet.com>
* Amit Shah <amit.shah@qumranet.com>
* Ben-Ami Yassour <benami@il.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include <linux/kvm_host.h>
#include "irq.h"
#include "mmu.h"
#include "i8254.h"
#include "tss.h"
#include "kvm_cache_regs.h"
#include "x86.h"
#include "cpuid.h"
#include "assigned-dev.h"
#include "pmu.h"
#include "hyperv.h"
#include <linux/clocksource.h>
#include <linux/interrupt.h>
#include <linux/kvm.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/mman.h>
#include <linux/highmem.h>
#include <linux/iommu.h>
#include <linux/intel-iommu.h>
#include <linux/cpufreq.h>
#include <linux/user-return-notifier.h>
#include <linux/srcu.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/perf_event.h>
#include <linux/uaccess.h>
#include <linux/hash.h>
#include <linux/pci.h>
#include <linux/timekeeper_internal.h>
#include <linux/pvclock_gtod.h>
#include <trace/events/kvm.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
2009-09-09 17:22:48 +00:00
#include <asm/debugreg.h>
#include <asm/msr.h>
#include <asm/desc.h>
#include <asm/mce.h>
#include <linux/kernel_stat.h>
#include <asm/fpu/internal.h> /* Ugh! */
#include <asm/pvclock.h>
#include <asm/div64.h>
#define MAX_IO_MSRS 256
#define KVM_MAX_MCE_BANKS 32
#define KVM_MCE_CAP_SUPPORTED (MCG_CTL_P | MCG_SER_P)
#define emul_to_vcpu(ctxt) \
container_of(ctxt, struct kvm_vcpu, arch.emulate_ctxt)
/* EFER defaults:
* - enable syscall per default because its emulated by KVM
* - enable LME and LMA per default on 64 bit KVM
*/
#ifdef CONFIG_X86_64
static
u64 __read_mostly efer_reserved_bits = ~((u64)(EFER_SCE | EFER_LME | EFER_LMA));
#else
static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
#endif
#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
static void update_cr8_intercept(struct kvm_vcpu *vcpu);
static void process_nmi(struct kvm_vcpu *vcpu);
static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
struct kvm_x86_ops *kvm_x86_ops;
EXPORT_SYMBOL_GPL(kvm_x86_ops);
static bool ignore_msrs = 0;
module_param(ignore_msrs, bool, S_IRUGO | S_IWUSR);
unsigned int min_timer_period_us = 500;
module_param(min_timer_period_us, uint, S_IRUGO | S_IWUSR);
static bool __read_mostly kvmclock_periodic_sync = true;
module_param(kvmclock_periodic_sync, bool, S_IRUGO);
bool kvm_has_tsc_control;
EXPORT_SYMBOL_GPL(kvm_has_tsc_control);
u32 kvm_max_guest_tsc_khz;
EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz);
2012-02-03 17:43:50 +00:00
/* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
static u32 tsc_tolerance_ppm = 250;
module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);
/* lapic timer advance (tscdeadline mode only) in nanoseconds */
unsigned int lapic_timer_advance_ns = 0;
module_param(lapic_timer_advance_ns, uint, S_IRUGO | S_IWUSR);
static bool backwards_tsc_observed = false;
#define KVM_NR_SHARED_MSRS 16
struct kvm_shared_msrs_global {
int nr;
u32 msrs[KVM_NR_SHARED_MSRS];
};
struct kvm_shared_msrs {
struct user_return_notifier urn;
bool registered;
struct kvm_shared_msr_values {
u64 host;
u64 curr;
} values[KVM_NR_SHARED_MSRS];
};
static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
static struct kvm_shared_msrs __percpu *shared_msrs;
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "pf_fixed", VCPU_STAT(pf_fixed) },
{ "pf_guest", VCPU_STAT(pf_guest) },
{ "tlb_flush", VCPU_STAT(tlb_flush) },
{ "invlpg", VCPU_STAT(invlpg) },
{ "exits", VCPU_STAT(exits) },
{ "io_exits", VCPU_STAT(io_exits) },
{ "mmio_exits", VCPU_STAT(mmio_exits) },
{ "signal_exits", VCPU_STAT(signal_exits) },
{ "irq_window", VCPU_STAT(irq_window_exits) },
{ "nmi_window", VCPU_STAT(nmi_window_exits) },
{ "halt_exits", VCPU_STAT(halt_exits) },
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-04 17:20:58 +00:00
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll) },
{ "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) },
{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
{ "hypercalls", VCPU_STAT(hypercalls) },
{ "request_irq", VCPU_STAT(request_irq_exits) },
{ "irq_exits", VCPU_STAT(irq_exits) },
{ "host_state_reload", VCPU_STAT(host_state_reload) },
{ "efer_reload", VCPU_STAT(efer_reload) },
{ "fpu_reload", VCPU_STAT(fpu_reload) },
{ "insn_emulation", VCPU_STAT(insn_emulation) },
{ "insn_emulation_fail", VCPU_STAT(insn_emulation_fail) },
{ "irq_injections", VCPU_STAT(irq_injections) },
{ "nmi_injections", VCPU_STAT(nmi_injections) },
{ "mmu_shadow_zapped", VM_STAT(mmu_shadow_zapped) },
{ "mmu_pte_write", VM_STAT(mmu_pte_write) },
{ "mmu_pte_updated", VM_STAT(mmu_pte_updated) },
{ "mmu_pde_zapped", VM_STAT(mmu_pde_zapped) },
{ "mmu_flooded", VM_STAT(mmu_flooded) },
{ "mmu_recycled", VM_STAT(mmu_recycled) },
{ "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
{ "mmu_unsync", VM_STAT(mmu_unsync) },
{ "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
{ "largepages", VM_STAT(lpages) },
{ NULL }
};
u64 __read_mostly host_xcr0;
static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);
static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
{
int i;
for (i = 0; i < roundup_pow_of_two(ASYNC_PF_PER_VCPU); i++)
vcpu->arch.apf.gfns[i] = ~0;
}
static void kvm_on_user_return(struct user_return_notifier *urn)
{
unsigned slot;
struct kvm_shared_msrs *locals
= container_of(urn, struct kvm_shared_msrs, urn);
struct kvm_shared_msr_values *values;
for (slot = 0; slot < shared_msrs_global.nr; ++slot) {
values = &locals->values[slot];
if (values->host != values->curr) {
wrmsrl(shared_msrs_global.msrs[slot], values->host);
values->curr = values->host;
}
}
locals->registered = false;
user_return_notifier_unregister(urn);
}
static void shared_msr_update(unsigned slot, u32 msr)
{
u64 value;
unsigned int cpu = smp_processor_id();
struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
/* only read, and nobody should modify it at this time,
* so don't need lock */
if (slot >= shared_msrs_global.nr) {
printk(KERN_ERR "kvm: invalid MSR slot!");
return;
}
rdmsrl_safe(msr, &value);
smsr->values[slot].host = value;
smsr->values[slot].curr = value;
}
void kvm_define_shared_msr(unsigned slot, u32 msr)
{
BUG_ON(slot >= KVM_NR_SHARED_MSRS);
shared_msrs_global.msrs[slot] = msr;
if (slot >= shared_msrs_global.nr)
shared_msrs_global.nr = slot + 1;
}
EXPORT_SYMBOL_GPL(kvm_define_shared_msr);
static void kvm_shared_msr_cpu_online(void)
{
unsigned i;
for (i = 0; i < shared_msrs_global.nr; ++i)
shared_msr_update(i, shared_msrs_global.msrs[i]);
}
int kvm_set_shared_msr(unsigned slot, u64 value, u64 mask)
{
unsigned int cpu = smp_processor_id();
struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
int err;
if (((value ^ smsr->values[slot].curr) & mask) == 0)
return 0;
smsr->values[slot].curr = value;
err = wrmsrl_safe(shared_msrs_global.msrs[slot], value);
if (err)
return 1;
if (!smsr->registered) {
smsr->urn.on_user_return = kvm_on_user_return;
user_return_notifier_register(&smsr->urn);
smsr->registered = true;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_shared_msr);
static void drop_user_return_notifiers(void)
{
unsigned int cpu = smp_processor_id();
struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
if (smsr->registered)
kvm_on_user_return(&smsr->urn);
}
u64 kvm_get_apic_base(struct kvm_vcpu *vcpu)
{
return vcpu->arch.apic_base;
}
EXPORT_SYMBOL_GPL(kvm_get_apic_base);
int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
u64 old_state = vcpu->arch.apic_base &
(MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE);
u64 new_state = msr_info->data &
(MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE);
u64 reserved_bits = ((~0ULL) << cpuid_maxphyaddr(vcpu)) |
0x2ff | (guest_cpuid_has_x2apic(vcpu) ? 0 : X2APIC_ENABLE);
if (!msr_info->host_initiated &&
((msr_info->data & reserved_bits) != 0 ||
new_state == X2APIC_ENABLE ||
(new_state == MSR_IA32_APICBASE_ENABLE &&
old_state == (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) ||
(new_state == (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE) &&
old_state == 0)))
return 1;
kvm_lapic_set_base(vcpu, msr_info->data);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_apic_base);
asmlinkage __visible void kvm_spurious_fault(void)
{
/* Fault while not rebooting. We want the trace. */
BUG();
}
EXPORT_SYMBOL_GPL(kvm_spurious_fault);
#define EXCPT_BENIGN 0
#define EXCPT_CONTRIBUTORY 1
#define EXCPT_PF 2
static int exception_class(int vector)
{
switch (vector) {
case PF_VECTOR:
return EXCPT_PF;
case DE_VECTOR:
case TS_VECTOR:
case NP_VECTOR:
case SS_VECTOR:
case GP_VECTOR:
return EXCPT_CONTRIBUTORY;
default:
break;
}
return EXCPT_BENIGN;
}
#define EXCPT_FAULT 0
#define EXCPT_TRAP 1
#define EXCPT_ABORT 2
#define EXCPT_INTERRUPT 3
static int exception_type(int vector)
{
unsigned int mask;
if (WARN_ON(vector > 31 || vector == NMI_VECTOR))
return EXCPT_INTERRUPT;
mask = 1 << vector;
/* #DB is trap, as instruction watchpoints are handled elsewhere */
if (mask & ((1 << DB_VECTOR) | (1 << BP_VECTOR) | (1 << OF_VECTOR)))
return EXCPT_TRAP;
if (mask & ((1 << DF_VECTOR) | (1 << MC_VECTOR)))
return EXCPT_ABORT;
/* Reserved exceptions will result in fault */
return EXCPT_FAULT;
}
static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
unsigned nr, bool has_error, u32 error_code,
bool reinject)
{
u32 prev_nr;
int class1, class2;
kvm_make_request(KVM_REQ_EVENT, vcpu);
if (!vcpu->arch.exception.pending) {
queue:
if (has_error && !is_protmode(vcpu))
has_error = false;
vcpu->arch.exception.pending = true;
vcpu->arch.exception.has_error_code = has_error;
vcpu->arch.exception.nr = nr;
vcpu->arch.exception.error_code = error_code;
vcpu->arch.exception.reinject = reinject;
return;
}
/* to check exception */
prev_nr = vcpu->arch.exception.nr;
if (prev_nr == DF_VECTOR) {
/* triple fault -> shutdown */
kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
return;
}
class1 = exception_class(prev_nr);
class2 = exception_class(nr);
if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY)
|| (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) {
/* generate double fault per SDM Table 5-5 */
vcpu->arch.exception.pending = true;
vcpu->arch.exception.has_error_code = true;
vcpu->arch.exception.nr = DF_VECTOR;
vcpu->arch.exception.error_code = 0;
} else
/* replace previous exception with a new one in a hope
that instruction re-execution will regenerate lost
exception */
goto queue;
}
void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
kvm_multiple_exception(vcpu, nr, false, 0, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception);
void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
kvm_multiple_exception(vcpu, nr, false, 0, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception);
void kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err)
{
if (err)
kvm_inject_gp(vcpu, 0);
else
kvm_x86_ops->skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_complete_insn_gp);
void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
++vcpu->stat.pf_guest;
vcpu->arch.cr2 = fault->address;
kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code);
}
EXPORT_SYMBOL_GPL(kvm_inject_page_fault);
static bool kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
if (mmu_is_nested(vcpu) && !fault->nested_page_fault)
vcpu->arch.nested_mmu.inject_page_fault(vcpu, fault);
else
vcpu->arch.mmu.inject_page_fault(vcpu, fault);
return fault->nested_page_fault;
}
void kvm_inject_nmi(struct kvm_vcpu *vcpu)
{
atomic_inc(&vcpu->arch.nmi_queued);
kvm_make_request(KVM_REQ_NMI, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_inject_nmi);
void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
kvm_multiple_exception(vcpu, nr, true, error_code, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception_e);
void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
kvm_multiple_exception(vcpu, nr, true, error_code, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception_e);
/*
* Checks if cpl <= required_cpl; if true, return true. Otherwise queue
* a #GP and return false.
*/
bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
{
if (kvm_x86_ops->get_cpl(vcpu) <= required_cpl)
return true;
kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
return false;
}
EXPORT_SYMBOL_GPL(kvm_require_cpl);
bool kvm_require_dr(struct kvm_vcpu *vcpu, int dr)
{
if ((dr != 4 && dr != 5) || !kvm_read_cr4_bits(vcpu, X86_CR4_DE))
return true;
kvm_queue_exception(vcpu, UD_VECTOR);
return false;
}
EXPORT_SYMBOL_GPL(kvm_require_dr);
/*
* This function will be used to read from the physical memory of the currently
* running guest. The difference to kvm_vcpu_read_guest_page is that this function
* can read from guest physical or from the guest's guest physical memory.
*/
int kvm_read_guest_page_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
gfn_t ngfn, void *data, int offset, int len,
u32 access)
{
struct x86_exception exception;
gfn_t real_gfn;
gpa_t ngpa;
ngpa = gfn_to_gpa(ngfn);
real_gfn = mmu->translate_gpa(vcpu, ngpa, access, &exception);
if (real_gfn == UNMAPPED_GVA)
return -EFAULT;
real_gfn = gpa_to_gfn(real_gfn);
return kvm_vcpu_read_guest_page(vcpu, real_gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_read_guest_page_mmu);
static int kvm_read_nested_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
void *data, int offset, int len, u32 access)
{
return kvm_read_guest_page_mmu(vcpu, vcpu->arch.walk_mmu, gfn,
data, offset, len, access);
}
/*
* Load the pae pdptrs. Return true is they are all valid.
*/
int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
{
gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
unsigned offset = ((cr3 & (PAGE_SIZE-1)) >> 5) << 2;
int i;
int ret;
u64 pdpte[ARRAY_SIZE(mmu->pdptrs)];
ret = kvm_read_guest_page_mmu(vcpu, mmu, pdpt_gfn, pdpte,
offset * sizeof(u64), sizeof(pdpte),
PFERR_USER_MASK|PFERR_WRITE_MASK);
if (ret < 0) {
ret = 0;
goto out;
}
for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
if (is_present_gpte(pdpte[i]) &&
(pdpte[i] &
vcpu->arch.mmu.guest_rsvd_check.rsvd_bits_mask[0][2])) {
ret = 0;
goto out;
}
}
ret = 1;
memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));
__set_bit(VCPU_EXREG_PDPTR,
(unsigned long *)&vcpu->arch.regs_avail);
__set_bit(VCPU_EXREG_PDPTR,
(unsigned long *)&vcpu->arch.regs_dirty);
out:
return ret;
}
EXPORT_SYMBOL_GPL(load_pdptrs);
static bool pdptrs_changed(struct kvm_vcpu *vcpu)
{
u64 pdpte[ARRAY_SIZE(vcpu->arch.walk_mmu->pdptrs)];
bool changed = true;
int offset;
gfn_t gfn;
int r;
if (is_long_mode(vcpu) || !is_pae(vcpu))
return false;
if (!test_bit(VCPU_EXREG_PDPTR,
(unsigned long *)&vcpu->arch.regs_avail))
return true;
gfn = (kvm_read_cr3(vcpu) & ~31u) >> PAGE_SHIFT;
offset = (kvm_read_cr3(vcpu) & ~31u) & (PAGE_SIZE - 1);
r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
PFERR_USER_MASK | PFERR_WRITE_MASK);
if (r < 0)
goto out;
changed = memcmp(pdpte, vcpu->arch.walk_mmu->pdptrs, sizeof(pdpte)) != 0;
out:
return changed;
}
int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
unsigned long old_cr0 = kvm_read_cr0(vcpu);
unsigned long update_bits = X86_CR0_PG | X86_CR0_WP;
cr0 |= X86_CR0_ET;
#ifdef CONFIG_X86_64
if (cr0 & 0xffffffff00000000UL)
return 1;
#endif
cr0 &= ~CR0_RESERVED_BITS;
if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD))
return 1;
if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE))
return 1;
if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
#ifdef CONFIG_X86_64
if ((vcpu->arch.efer & EFER_LME)) {
int cs_db, cs_l;
if (!is_pae(vcpu))
return 1;
kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
if (cs_l)
return 1;
} else
#endif
if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
kvm_read_cr3(vcpu)))
return 1;
}
if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
return 1;
kvm_x86_ops->set_cr0(vcpu, cr0);
if ((cr0 ^ old_cr0) & X86_CR0_PG) {
kvm_clear_async_pf_completion_queue(vcpu);
kvm_async_pf_hash_reset(vcpu);
}
if ((cr0 ^ old_cr0) & update_bits)
kvm_mmu_reset_context(vcpu);
if ((cr0 ^ old_cr0) & X86_CR0_CD)
kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr0);
void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
{
(void)kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
}
EXPORT_SYMBOL_GPL(kvm_lmsw);
static void kvm_load_guest_xcr0(struct kvm_vcpu *vcpu)
{
if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE) &&
!vcpu->guest_xcr0_loaded) {
/* kvm_set_xcr() also depends on this */
xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0);
vcpu->guest_xcr0_loaded = 1;
}
}
static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_xcr0_loaded) {
if (vcpu->arch.xcr0 != host_xcr0)
xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0);
vcpu->guest_xcr0_loaded = 0;
}
}
static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
u64 xcr0 = xcr;
u64 old_xcr0 = vcpu->arch.xcr0;
u64 valid_bits;
/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
if (index != XCR_XFEATURE_ENABLED_MASK)
return 1;
if (!(xcr0 & XSTATE_FP))
return 1;
if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
return 1;
/*
* Do not allow the guest to set bits that we do not support
* saving. However, xcr0 bit 0 is always set, even if the
* emulated CPU does not support XSAVE (see fx_init).
*/
valid_bits = vcpu->arch.guest_supported_xcr0 | XSTATE_FP;
if (xcr0 & ~valid_bits)
return 1;
if ((!(xcr0 & XSTATE_BNDREGS)) != (!(xcr0 & XSTATE_BNDCSR)))
return 1;
if (xcr0 & XSTATE_AVX512) {
if (!(xcr0 & XSTATE_YMM))
return 1;
if ((xcr0 & XSTATE_AVX512) != XSTATE_AVX512)
return 1;
}
kvm_put_guest_xcr0(vcpu);
vcpu->arch.xcr0 = xcr0;
if ((xcr0 ^ old_xcr0) & XSTATE_EXTEND_MASK)
kvm_update_cpuid(vcpu);
return 0;
}
int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
if (kvm_x86_ops->get_cpl(vcpu) != 0 ||
__kvm_set_xcr(vcpu, index, xcr)) {
kvm_inject_gp(vcpu, 0);
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_xcr);
int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
unsigned long old_cr4 = kvm_read_cr4(vcpu);
unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE |
X86_CR4_SMEP | X86_CR4_SMAP;
if (cr4 & CR4_RESERVED_BITS)
return 1;
if (!guest_cpuid_has_xsave(vcpu) && (cr4 & X86_CR4_OSXSAVE))
return 1;
if (!guest_cpuid_has_smep(vcpu) && (cr4 & X86_CR4_SMEP))
return 1;
if (!guest_cpuid_has_smap(vcpu) && (cr4 & X86_CR4_SMAP))
return 1;
if (!guest_cpuid_has_fsgsbase(vcpu) && (cr4 & X86_CR4_FSGSBASE))
return 1;
if (is_long_mode(vcpu)) {
if (!(cr4 & X86_CR4_PAE))
return 1;
} else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
&& ((cr4 ^ old_cr4) & pdptr_bits)
&& !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
kvm_read_cr3(vcpu)))
return 1;
if ((cr4 & X86_CR4_PCIDE) && !(old_cr4 & X86_CR4_PCIDE)) {
if (!guest_cpuid_has_pcid(vcpu))
return 1;
/* PCID can not be enabled when cr3[11:0]!=000H or EFER.LMA=0 */
if ((kvm_read_cr3(vcpu) & X86_CR3_PCID_MASK) || !is_long_mode(vcpu))
return 1;
}
if (kvm_x86_ops->set_cr4(vcpu, cr4))
return 1;
if (((cr4 ^ old_cr4) & pdptr_bits) ||
(!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
kvm_mmu_reset_context(vcpu);
if ((cr4 ^ old_cr4) & X86_CR4_OSXSAVE)
kvm_update_cpuid(vcpu);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr4);
int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
#ifdef CONFIG_X86_64
cr3 &= ~CR3_PCID_INVD;
#endif
if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) {
kvm_mmu_sync_roots(vcpu);
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
return 0;
}
if (is_long_mode(vcpu)) {
if (cr3 & CR3_L_MODE_RESERVED_BITS)
return 1;
} else if (is_pae(vcpu) && is_paging(vcpu) &&
!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
return 1;
vcpu->arch.cr3 = cr3;
__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
kvm_mmu_new_cr3(vcpu);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr3);
int kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
{
if (cr8 & CR8_RESERVED_BITS)
return 1;
if (irqchip_in_kernel(vcpu->kvm))
kvm_lapic_set_tpr(vcpu, cr8);
else
vcpu->arch.cr8 = cr8;
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr8);
unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu)
{
if (irqchip_in_kernel(vcpu->kvm))
return kvm_lapic_get_cr8(vcpu);
else
return vcpu->arch.cr8;
}
EXPORT_SYMBOL_GPL(kvm_get_cr8);
static void kvm_update_dr0123(struct kvm_vcpu *vcpu)
{
int i;
if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
for (i = 0; i < KVM_NR_DB_REGS; i++)
vcpu->arch.eff_db[i] = vcpu->arch.db[i];
vcpu->arch.switch_db_regs |= KVM_DEBUGREG_RELOAD;
}
}
static void kvm_update_dr6(struct kvm_vcpu *vcpu)
{
if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
kvm_x86_ops->set_dr6(vcpu, vcpu->arch.dr6);
}
static void kvm_update_dr7(struct kvm_vcpu *vcpu)
{
unsigned long dr7;
if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
dr7 = vcpu->arch.guest_debug_dr7;
else
dr7 = vcpu->arch.dr7;
kvm_x86_ops->set_dr7(vcpu, dr7);
vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_BP_ENABLED;
if (dr7 & DR7_BP_EN_MASK)
vcpu->arch.switch_db_regs |= KVM_DEBUGREG_BP_ENABLED;
}
static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
{
u64 fixed = DR6_FIXED_1;
if (!guest_cpuid_has_rtm(vcpu))
fixed |= DR6_RTM;
return fixed;
}
static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
switch (dr) {
case 0 ... 3:
vcpu->arch.db[dr] = val;
if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
vcpu->arch.eff_db[dr] = val;
break;
case 4:
/* fall through */
case 6:
if (val & 0xffffffff00000000ULL)
return -1; /* #GP */
vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);
kvm_update_dr6(vcpu);
break;
case 5:
/* fall through */
default: /* 7 */
if (val & 0xffffffff00000000ULL)
return -1; /* #GP */
vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
kvm_update_dr7(vcpu);
break;
}
return 0;
}
int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
if (__kvm_set_dr(vcpu, dr, val)) {
kvm_inject_gp(vcpu, 0);
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_dr);
int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
{
switch (dr) {
case 0 ... 3:
*val = vcpu->arch.db[dr];
break;
case 4:
/* fall through */
case 6:
if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
*val = vcpu->arch.dr6;
else
*val = kvm_x86_ops->get_dr6(vcpu);
break;
case 5:
/* fall through */
default: /* 7 */
*val = vcpu->arch.dr7;
break;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_get_dr);
bool kvm_rdpmc(struct kvm_vcpu *vcpu)
{
u32 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
u64 data;
int err;
err = kvm_pmu_rdpmc(vcpu, ecx, &data);
if (err)
return err;
kvm_register_write(vcpu, VCPU_REGS_RAX, (u32)data);
kvm_register_write(vcpu, VCPU_REGS_RDX, data >> 32);
return err;
}
EXPORT_SYMBOL_GPL(kvm_rdpmc);
/*
* List of msr numbers which we expose to userspace through KVM_GET_MSRS
* and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
*
* This list is modified at module load time to reflect the
* capabilities of the host cpu. This capabilities test skips MSRs that are
* kvm-specific. Those are put in emulated_msrs; filtering of emulated_msrs
* may depend on host virtualization features rather than host cpu features.
*/
static u32 msrs_to_save[] = {
MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
MSR_STAR,
#ifdef CONFIG_X86_64
MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS
};
static unsigned num_msrs_to_save;
static u32 emulated_msrs[] = {
MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC,
HV_X64_MSR_CRASH_P0, HV_X64_MSR_CRASH_P1, HV_X64_MSR_CRASH_P2,
HV_X64_MSR_CRASH_P3, HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL,
HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
MSR_KVM_PV_EOI_EN,
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
MSR_IA32_TSC_ADJUST,
MSR_IA32_TSCDEADLINE,
MSR_IA32_MISC_ENABLE,
MSR_IA32_MCG_STATUS,
MSR_IA32_MCG_CTL,
MSR_IA32_SMBASE,
};
static unsigned num_emulated_msrs;
bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
{
if (efer & efer_reserved_bits)
return false;
if (efer & EFER_FFXSR) {
struct kvm_cpuid_entry2 *feat;
feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
if (!feat || !(feat->edx & bit(X86_FEATURE_FXSR_OPT)))
return false;
}
if (efer & EFER_SVME) {
struct kvm_cpuid_entry2 *feat;
feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
if (!feat || !(feat->ecx & bit(X86_FEATURE_SVM)))
return false;
}
return true;
}
EXPORT_SYMBOL_GPL(kvm_valid_efer);
static int set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
u64 old_efer = vcpu->arch.efer;
if (!kvm_valid_efer(vcpu, efer))
return 1;
if (is_paging(vcpu)
&& (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
return 1;
efer &= ~EFER_LMA;
efer |= vcpu->arch.efer & EFER_LMA;
kvm_x86_ops->set_efer(vcpu, efer);
/* Update reserved bits */
if ((efer ^ old_efer) & EFER_NX)
kvm_mmu_reset_context(vcpu);
return 0;
}
void kvm_enable_efer_bits(u64 mask)
{
efer_reserved_bits &= ~mask;
}
EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);
/*
* Writes msr value into into the appropriate "register".
* Returns 0 on success, non-0 otherwise.
* Assumes vcpu_load() was already called.
*/
int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
KVM: x86: Check non-canonical addresses upon WRMSR Upon WRMSR, the CPU should inject #GP if a non-canonical value (address) is written to certain MSRs. The behavior is "almost" identical for AMD and Intel (ignoring MSRs that are not implemented in either architecture since they would anyhow #GP). However, IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if non-canonical address is written on Intel but not on AMD (which ignores the top 32-bits). Accordingly, this patch injects a #GP on the MSRs which behave identically on Intel and AMD. To eliminate the differences between the architecutres, the value which is written to IA32_SYSENTER_ESP and IA32_SYSENTER_EIP is turned to canonical value before writing instead of injecting a #GP. Some references from Intel and AMD manuals: According to Intel SDM description of WRMSR instruction #GP is expected on WRMSR "If the source register contains a non-canonical address and ECX specifies one of the following MSRs: IA32_DS_AREA, IA32_FS_BASE, IA32_GS_BASE, IA32_KERNEL_GS_BASE, IA32_LSTAR, IA32_SYSENTER_EIP, IA32_SYSENTER_ESP." According to AMD manual instruction manual: LSTAR/CSTAR (SYSCALL): "The WRMSR instruction loads the target RIP into the LSTAR and CSTAR registers. If an RIP written by WRMSR is not in canonical form, a general-protection exception (#GP) occurs." IA32_GS_BASE and IA32_FS_BASE (WRFSBASE/WRGSBASE): "The address written to the base field must be in canonical form or a #GP fault will occur." IA32_KERNEL_GS_BASE (SWAPGS): "The address stored in the KernelGSbase MSR must be in canonical form." This patch fixes CVE-2014-3610. Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-16 00:24:05 +00:00
switch (msr->index) {
case MSR_FS_BASE:
case MSR_GS_BASE:
case MSR_KERNEL_GS_BASE:
case MSR_CSTAR:
case MSR_LSTAR:
if (is_noncanonical_address(msr->data))
return 1;
break;
case MSR_IA32_SYSENTER_EIP:
case MSR_IA32_SYSENTER_ESP:
/*
* IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if
* non-canonical address is written on Intel but not on
* AMD (which ignores the top 32-bits, because it does
* not implement 64-bit SYSENTER).
*
* 64-bit code should hence be able to write a non-canonical
* value on AMD. Making the address canonical ensures that
* vmentry does not fail on Intel after writing a non-canonical
* value, and that something deterministic happens if the guest
* invokes 64-bit SYSENTER.
*/
msr->data = get_canonical(msr->data);
}
return kvm_x86_ops->set_msr(vcpu, msr);
}
KVM: x86: Check non-canonical addresses upon WRMSR Upon WRMSR, the CPU should inject #GP if a non-canonical value (address) is written to certain MSRs. The behavior is "almost" identical for AMD and Intel (ignoring MSRs that are not implemented in either architecture since they would anyhow #GP). However, IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if non-canonical address is written on Intel but not on AMD (which ignores the top 32-bits). Accordingly, this patch injects a #GP on the MSRs which behave identically on Intel and AMD. To eliminate the differences between the architecutres, the value which is written to IA32_SYSENTER_ESP and IA32_SYSENTER_EIP is turned to canonical value before writing instead of injecting a #GP. Some references from Intel and AMD manuals: According to Intel SDM description of WRMSR instruction #GP is expected on WRMSR "If the source register contains a non-canonical address and ECX specifies one of the following MSRs: IA32_DS_AREA, IA32_FS_BASE, IA32_GS_BASE, IA32_KERNEL_GS_BASE, IA32_LSTAR, IA32_SYSENTER_EIP, IA32_SYSENTER_ESP." According to AMD manual instruction manual: LSTAR/CSTAR (SYSCALL): "The WRMSR instruction loads the target RIP into the LSTAR and CSTAR registers. If an RIP written by WRMSR is not in canonical form, a general-protection exception (#GP) occurs." IA32_GS_BASE and IA32_FS_BASE (WRFSBASE/WRGSBASE): "The address written to the base field must be in canonical form or a #GP fault will occur." IA32_KERNEL_GS_BASE (SWAPGS): "The address stored in the KernelGSbase MSR must be in canonical form." This patch fixes CVE-2014-3610. Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-16 00:24:05 +00:00
EXPORT_SYMBOL_GPL(kvm_set_msr);
/*
* Adapt set_msr() to msr_io()'s calling convention
*/
static int do_get_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
struct msr_data msr;
int r;
msr.index = index;
msr.host_initiated = true;
r = kvm_get_msr(vcpu, &msr);
if (r)
return r;
*data = msr.data;
return 0;
}
static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
struct msr_data msr;
msr.data = *data;
msr.index = index;
msr.host_initiated = true;
return kvm_set_msr(vcpu, &msr);
}
#ifdef CONFIG_X86_64
struct pvclock_gtod_data {
seqcount_t seq;
struct { /* extract of a clocksource struct */
int vclock_mode;
cycle_t cycle_last;
cycle_t mask;
u32 mult;
u32 shift;
} clock;
u64 boot_ns;
u64 nsec_base;
};
static struct pvclock_gtod_data pvclock_gtod_data;
static void update_pvclock_gtod(struct timekeeper *tk)
{
struct pvclock_gtod_data *vdata = &pvclock_gtod_data;
u64 boot_ns;
boot_ns = ktime_to_ns(ktime_add(tk->tkr_mono.base, tk->offs_boot));
write_seqcount_begin(&vdata->seq);
/* copy pvclock gtod data */
vdata->clock.vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
vdata->clock.cycle_last = tk->tkr_mono.cycle_last;
vdata->clock.mask = tk->tkr_mono.mask;
vdata->clock.mult = tk->tkr_mono.mult;
vdata->clock.shift = tk->tkr_mono.shift;
vdata->boot_ns = boot_ns;
vdata->nsec_base = tk->tkr_mono.xtime_nsec;
write_seqcount_end(&vdata->seq);
}
#endif
void kvm_set_pending_timer(struct kvm_vcpu *vcpu)
{
/*
* Note: KVM_REQ_PENDING_TIMER is implicitly checked in
* vcpu_enter_guest. This function is only called from
* the physical CPU that is running vcpu.
*/
kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
}
static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
{
int version;
int r;
struct pvclock_wall_clock wc;
struct timespec boot;
if (!wall_clock)
return;
r = kvm_read_guest(kvm, wall_clock, &version, sizeof(version));
if (r)
return;
if (version & 1)
++version; /* first time write, random junk */
++version;
kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
/*
* The guest calculates current wall clock time by adding
* system time (updated by kvm_guest_time_update below) to the
* wall clock specified here. guest system time equals host
* system time for us, thus we must fill in host boot time here.
*/
getboottime(&boot);
if (kvm->arch.kvmclock_offset) {
struct timespec ts = ns_to_timespec(kvm->arch.kvmclock_offset);
boot = timespec_sub(boot, ts);
}
wc.sec = boot.tv_sec;
wc.nsec = boot.tv_nsec;
wc.version = version;
kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc));
version++;
kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
}
static uint32_t div_frac(uint32_t dividend, uint32_t divisor)
{
uint32_t quotient, remainder;
/* Don't try to replace with do_div(), this one calculates
* "(dividend << 32) / divisor" */
__asm__ ( "divl %4"
: "=a" (quotient), "=d" (remainder)
: "0" (0), "1" (dividend), "r" (divisor) );
return quotient;
}
static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
s8 *pshift, u32 *pmultiplier)
{
uint64_t scaled64;
int32_t shift = 0;
uint64_t tps64;
uint32_t tps32;
tps64 = base_khz * 1000LL;
scaled64 = scaled_khz * 1000LL;
while (tps64 > scaled64*2 || tps64 & 0xffffffff00000000ULL) {
tps64 >>= 1;
shift--;
}
tps32 = (uint32_t)tps64;
while (tps32 <= scaled64 || scaled64 & 0xffffffff00000000ULL) {
if (scaled64 & 0xffffffff00000000ULL || tps32 & 0x80000000)
scaled64 >>= 1;
else
tps32 <<= 1;
shift++;
}
*pshift = shift;
*pmultiplier = div_frac(scaled64, tps32);
pr_debug("%s: base_khz %u => %u, shift %d, mul %u\n",
__func__, base_khz, scaled_khz, shift, *pmultiplier);
}
#ifdef CONFIG_X86_64
static atomic_t kvm_guest_has_master_clock = ATOMIC_INIT(0);
#endif
static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz);
static unsigned long max_tsc_khz;
2012-02-03 17:43:50 +00:00
static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
{
2012-02-03 17:43:50 +00:00
return pvclock_scale_delta(nsec, vcpu->arch.virtual_tsc_mult,
vcpu->arch.virtual_tsc_shift);
}
2012-02-03 17:43:50 +00:00
static u32 adjust_tsc_khz(u32 khz, s32 ppm)
{
2012-02-03 17:43:50 +00:00
u64 v = (u64)khz * (1000000 + ppm);
do_div(v, 1000000);
return v;
}
2012-02-03 17:43:50 +00:00
static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz)
{
2012-02-03 17:43:50 +00:00
u32 thresh_lo, thresh_hi;
int use_scaling = 0;
/* tsc_khz can be zero if TSC calibration fails */
if (this_tsc_khz == 0)
return;
/* Compute a scale to convert nanoseconds in TSC cycles */
kvm_get_time_scale(this_tsc_khz, NSEC_PER_SEC / 1000,
2012-02-03 17:43:50 +00:00
&vcpu->arch.virtual_tsc_shift,
&vcpu->arch.virtual_tsc_mult);
vcpu->arch.virtual_tsc_khz = this_tsc_khz;
/*
* Compute the variation in TSC rate which is acceptable
* within the range of tolerance and decide if the
* rate being applied is within that bounds of the hardware
* rate. If so, no scaling or compensation need be done.
*/
thresh_lo = adjust_tsc_khz(tsc_khz, -tsc_tolerance_ppm);
thresh_hi = adjust_tsc_khz(tsc_khz, tsc_tolerance_ppm);
if (this_tsc_khz < thresh_lo || this_tsc_khz > thresh_hi) {
pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", this_tsc_khz, thresh_lo, thresh_hi);
use_scaling = 1;
}
kvm_x86_ops->set_tsc_khz(vcpu, this_tsc_khz, use_scaling);
}
static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
{
u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.this_tsc_nsec,
2012-02-03 17:43:50 +00:00
vcpu->arch.virtual_tsc_mult,
vcpu->arch.virtual_tsc_shift);
tsc += vcpu->arch.this_tsc_write;
return tsc;
}
static void kvm_track_tsc_matching(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
bool vcpus_matched;
struct kvm_arch *ka = &vcpu->kvm->arch;
struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
vcpus_matched = (ka->nr_vcpus_matched_tsc + 1 ==
atomic_read(&vcpu->kvm->online_vcpus));
/*
* Once the masterclock is enabled, always perform request in
* order to update it.
*
* In order to enable masterclock, the host clocksource must be TSC
* and the vcpus need to have matched TSCs. When that happens,
* perform request to enable masterclock.
*/
if (ka->use_master_clock ||
(gtod->clock.vclock_mode == VCLOCK_TSC && vcpus_matched))
kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
trace_kvm_track_tsc(vcpu->vcpu_id, ka->nr_vcpus_matched_tsc,
atomic_read(&vcpu->kvm->online_vcpus),
ka->use_master_clock, gtod->clock.vclock_mode);
#endif
}
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
static void update_ia32_tsc_adjust_msr(struct kvm_vcpu *vcpu, s64 offset)
{
u64 curr_offset = kvm_x86_ops->read_tsc_offset(vcpu);
vcpu->arch.ia32_tsc_adjust_msr += offset - curr_offset;
}
void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
struct kvm *kvm = vcpu->kvm;
u64 offset, ns, elapsed;
unsigned long flags;
s64 usdiff;
bool matched;
KVM: x86: fix TSC matching I've observed kvmclock being marked as unstable on a modern single-socket system with a stable TSC and qemu-1.6.2 or qemu-2.0.0. The culprit was failure in TSC matching because of overflow of kvm_arch::nr_vcpus_matched_tsc in case there were multiple TSC writes in a single synchronization cycle. Turns out that qemu does multiple TSC writes during init, below is the evidence of that (qemu-2.0.0): The first one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa04cfd6b : kvm_arch_vcpu_postcreate+0x4b/0x80 [kvm] 0xffffffffa04b8188 : kvm_vm_ioctl+0x418/0x750 [kvm] The second one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1641 #4 cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:330 #5 cpu_synchronize_all_post_init () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:521 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4390 The third one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1635 #4 cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:323 #5 cpu_synchronize_all_post_reset () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:512 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4482 The fix is to count each vCPU only once when matched, so that nr_vcpus_matched_tsc holds the size of the matched set. This is achieved by reusing generation counters. Every vCPU with this_tsc_generation == cur_tsc_generation is in the matched set. The match set is cleared by setting cur_tsc_generation to a value which no other vCPU is set to (by incrementing it). I needed to bump up the counter size form u8 to u64 to ensure it never overflows. Otherwise in cases TSC is not written the same number of times on each vCPU the counter could overflow and incorrectly indicate some vCPUs as being in the matched set. This scenario seems unlikely but I'm not sure if it can be disregarded. Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-24 07:42:43 +00:00
bool already_matched;
u64 data = msr->data;
raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
ns = get_kernel_ns();
elapsed = ns - kvm->arch.last_tsc_nsec;
if (vcpu->arch.virtual_tsc_khz) {
int faulted = 0;
/* n.b - signed multiplication and division required */
usdiff = data - kvm->arch.last_tsc_write;
#ifdef CONFIG_X86_64
usdiff = (usdiff * 1000) / vcpu->arch.virtual_tsc_khz;
#else
/* do_div() only does unsigned */
asm("1: idivl %[divisor]\n"
"2: xor %%edx, %%edx\n"
" movl $0, %[faulted]\n"
"3:\n"
".section .fixup,\"ax\"\n"
"4: movl $1, %[faulted]\n"
" jmp 3b\n"
".previous\n"
_ASM_EXTABLE(1b, 4b)
: "=A"(usdiff), [faulted] "=r" (faulted)
: "A"(usdiff * 1000), [divisor] "rm"(vcpu->arch.virtual_tsc_khz));
#endif
do_div(elapsed, 1000);
usdiff -= elapsed;
if (usdiff < 0)
usdiff = -usdiff;
/* idivl overflow => difference is larger than USEC_PER_SEC */
if (faulted)
usdiff = USEC_PER_SEC;
} else
usdiff = USEC_PER_SEC; /* disable TSC match window below */
/*
* Special case: TSC write with a small delta (1 second) of virtual
* cycle time against real time is interpreted as an attempt to
* synchronize the CPU.
*
* For a reliable TSC, we can match TSC offsets, and for an unstable
* TSC, we add elapsed time in this computation. We could let the
* compensation code attempt to catch up if we fall behind, but
* it's better to try to match offsets from the beginning.
*/
if (usdiff < USEC_PER_SEC &&
vcpu->arch.virtual_tsc_khz == kvm->arch.last_tsc_khz) {
if (!check_tsc_unstable()) {
offset = kvm->arch.cur_tsc_offset;
pr_debug("kvm: matched tsc offset for %llu\n", data);
} else {
u64 delta = nsec_to_cycles(vcpu, elapsed);
data += delta;
offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
pr_debug("kvm: adjusted tsc offset by %llu\n", delta);
}
matched = true;
KVM: x86: fix TSC matching I've observed kvmclock being marked as unstable on a modern single-socket system with a stable TSC and qemu-1.6.2 or qemu-2.0.0. The culprit was failure in TSC matching because of overflow of kvm_arch::nr_vcpus_matched_tsc in case there were multiple TSC writes in a single synchronization cycle. Turns out that qemu does multiple TSC writes during init, below is the evidence of that (qemu-2.0.0): The first one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa04cfd6b : kvm_arch_vcpu_postcreate+0x4b/0x80 [kvm] 0xffffffffa04b8188 : kvm_vm_ioctl+0x418/0x750 [kvm] The second one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1641 #4 cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:330 #5 cpu_synchronize_all_post_init () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:521 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4390 The third one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1635 #4 cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:323 #5 cpu_synchronize_all_post_reset () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:512 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4482 The fix is to count each vCPU only once when matched, so that nr_vcpus_matched_tsc holds the size of the matched set. This is achieved by reusing generation counters. Every vCPU with this_tsc_generation == cur_tsc_generation is in the matched set. The match set is cleared by setting cur_tsc_generation to a value which no other vCPU is set to (by incrementing it). I needed to bump up the counter size form u8 to u64 to ensure it never overflows. Otherwise in cases TSC is not written the same number of times on each vCPU the counter could overflow and incorrectly indicate some vCPUs as being in the matched set. This scenario seems unlikely but I'm not sure if it can be disregarded. Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-24 07:42:43 +00:00
already_matched = (vcpu->arch.this_tsc_generation == kvm->arch.cur_tsc_generation);
} else {
/*
* We split periods of matched TSC writes into generations.
* For each generation, we track the original measured
* nanosecond time, offset, and write, so if TSCs are in
* sync, we can match exact offset, and if not, we can match
* exact software computation in compute_guest_tsc()
*
* These values are tracked in kvm->arch.cur_xxx variables.
*/
kvm->arch.cur_tsc_generation++;
kvm->arch.cur_tsc_nsec = ns;
kvm->arch.cur_tsc_write = data;
kvm->arch.cur_tsc_offset = offset;
matched = false;
KVM: x86: fix TSC matching I've observed kvmclock being marked as unstable on a modern single-socket system with a stable TSC and qemu-1.6.2 or qemu-2.0.0. The culprit was failure in TSC matching because of overflow of kvm_arch::nr_vcpus_matched_tsc in case there were multiple TSC writes in a single synchronization cycle. Turns out that qemu does multiple TSC writes during init, below is the evidence of that (qemu-2.0.0): The first one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa04cfd6b : kvm_arch_vcpu_postcreate+0x4b/0x80 [kvm] 0xffffffffa04b8188 : kvm_vm_ioctl+0x418/0x750 [kvm] The second one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1641 #4 cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:330 #5 cpu_synchronize_all_post_init () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:521 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4390 The third one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1635 #4 cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:323 #5 cpu_synchronize_all_post_reset () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:512 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4482 The fix is to count each vCPU only once when matched, so that nr_vcpus_matched_tsc holds the size of the matched set. This is achieved by reusing generation counters. Every vCPU with this_tsc_generation == cur_tsc_generation is in the matched set. The match set is cleared by setting cur_tsc_generation to a value which no other vCPU is set to (by incrementing it). I needed to bump up the counter size form u8 to u64 to ensure it never overflows. Otherwise in cases TSC is not written the same number of times on each vCPU the counter could overflow and incorrectly indicate some vCPUs as being in the matched set. This scenario seems unlikely but I'm not sure if it can be disregarded. Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-24 07:42:43 +00:00
pr_debug("kvm: new tsc generation %llu, clock %llu\n",
kvm->arch.cur_tsc_generation, data);
}
/*
* We also track th most recent recorded KHZ, write and time to
* allow the matching interval to be extended at each write.
*/
kvm->arch.last_tsc_nsec = ns;
kvm->arch.last_tsc_write = data;
kvm->arch.last_tsc_khz = vcpu->arch.virtual_tsc_khz;
vcpu->arch.last_guest_tsc = data;
/* Keep track of which generation this VCPU has synchronized to */
vcpu->arch.this_tsc_generation = kvm->arch.cur_tsc_generation;
vcpu->arch.this_tsc_nsec = kvm->arch.cur_tsc_nsec;
vcpu->arch.this_tsc_write = kvm->arch.cur_tsc_write;
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
if (guest_cpuid_has_tsc_adjust(vcpu) && !msr->host_initiated)
update_ia32_tsc_adjust_msr(vcpu, offset);
kvm_x86_ops->write_tsc_offset(vcpu, offset);
raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
spin_lock(&kvm->arch.pvclock_gtod_sync_lock);
KVM: x86: fix TSC matching I've observed kvmclock being marked as unstable on a modern single-socket system with a stable TSC and qemu-1.6.2 or qemu-2.0.0. The culprit was failure in TSC matching because of overflow of kvm_arch::nr_vcpus_matched_tsc in case there were multiple TSC writes in a single synchronization cycle. Turns out that qemu does multiple TSC writes during init, below is the evidence of that (qemu-2.0.0): The first one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa04cfd6b : kvm_arch_vcpu_postcreate+0x4b/0x80 [kvm] 0xffffffffa04b8188 : kvm_vm_ioctl+0x418/0x750 [kvm] The second one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1641 #4 cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:330 #5 cpu_synchronize_all_post_init () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:521 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4390 The third one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1635 #4 cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:323 #5 cpu_synchronize_all_post_reset () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:512 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4482 The fix is to count each vCPU only once when matched, so that nr_vcpus_matched_tsc holds the size of the matched set. This is achieved by reusing generation counters. Every vCPU with this_tsc_generation == cur_tsc_generation is in the matched set. The match set is cleared by setting cur_tsc_generation to a value which no other vCPU is set to (by incrementing it). I needed to bump up the counter size form u8 to u64 to ensure it never overflows. Otherwise in cases TSC is not written the same number of times on each vCPU the counter could overflow and incorrectly indicate some vCPUs as being in the matched set. This scenario seems unlikely but I'm not sure if it can be disregarded. Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-24 07:42:43 +00:00
if (!matched) {
kvm->arch.nr_vcpus_matched_tsc = 0;
KVM: x86: fix TSC matching I've observed kvmclock being marked as unstable on a modern single-socket system with a stable TSC and qemu-1.6.2 or qemu-2.0.0. The culprit was failure in TSC matching because of overflow of kvm_arch::nr_vcpus_matched_tsc in case there were multiple TSC writes in a single synchronization cycle. Turns out that qemu does multiple TSC writes during init, below is the evidence of that (qemu-2.0.0): The first one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa04cfd6b : kvm_arch_vcpu_postcreate+0x4b/0x80 [kvm] 0xffffffffa04b8188 : kvm_vm_ioctl+0x418/0x750 [kvm] The second one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1641 #4 cpu_synchronize_post_init at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:330 #5 cpu_synchronize_all_post_init () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:521 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4390 The third one: 0xffffffffa08ff2b4 : vmx_write_tsc_offset+0xa4/0xb0 [kvm_intel] 0xffffffffa04c9c05 : kvm_write_tsc+0x1a5/0x360 [kvm] 0xffffffffa090610d : vmx_set_msr+0x29d/0x350 [kvm_intel] 0xffffffffa04be83b : do_set_msr+0x3b/0x60 [kvm] 0xffffffffa04c10a8 : msr_io+0xc8/0x160 [kvm] 0xffffffffa04caeb6 : kvm_arch_vcpu_ioctl+0xc86/0x1060 [kvm] 0xffffffffa04b6797 : kvm_vcpu_ioctl+0xc7/0x5a0 [kvm] #0 kvm_vcpu_ioctl at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1780 #1 kvm_put_msrs at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1270 #2 kvm_arch_put_registers at /build/buildd/qemu-2.0.0+dfsg/target-i386/kvm.c:1909 #3 kvm_cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/kvm-all.c:1635 #4 cpu_synchronize_post_reset at /build/buildd/qemu-2.0.0+dfsg/include/sysemu/kvm.h:323 #5 cpu_synchronize_all_post_reset () at /build/buildd/qemu-2.0.0+dfsg/cpus.c:512 #6 main at /build/buildd/qemu-2.0.0+dfsg/vl.c:4482 The fix is to count each vCPU only once when matched, so that nr_vcpus_matched_tsc holds the size of the matched set. This is achieved by reusing generation counters. Every vCPU with this_tsc_generation == cur_tsc_generation is in the matched set. The match set is cleared by setting cur_tsc_generation to a value which no other vCPU is set to (by incrementing it). I needed to bump up the counter size form u8 to u64 to ensure it never overflows. Otherwise in cases TSC is not written the same number of times on each vCPU the counter could overflow and incorrectly indicate some vCPUs as being in the matched set. This scenario seems unlikely but I'm not sure if it can be disregarded. Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-24 07:42:43 +00:00
} else if (!already_matched) {
kvm->arch.nr_vcpus_matched_tsc++;
}
kvm_track_tsc_matching(vcpu);
spin_unlock(&kvm->arch.pvclock_gtod_sync_lock);
}
EXPORT_SYMBOL_GPL(kvm_write_tsc);
#ifdef CONFIG_X86_64
static cycle_t read_tsc(void)
{
cycle_t ret = (cycle_t)rdtsc_ordered();
u64 last = pvclock_gtod_data.clock.cycle_last;
if (likely(ret >= last))
return ret;
/*
* GCC likes to generate cmov here, but this branch is extremely
* predictable (it's just a funciton of time and the likely is
* very likely) and there's a data dependence, so force GCC
* to generate a branch instead. I don't barrier() because
* we don't actually need a barrier, and if this function
* ever gets inlined it will generate worse code.
*/
asm volatile ("");
return last;
}
static inline u64 vgettsc(cycle_t *cycle_now)
{
long v;
struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
*cycle_now = read_tsc();
v = (*cycle_now - gtod->clock.cycle_last) & gtod->clock.mask;
return v * gtod->clock.mult;
}
static int do_monotonic_boot(s64 *t, cycle_t *cycle_now)
{
struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
unsigned long seq;
int mode;
u64 ns;
do {
seq = read_seqcount_begin(&gtod->seq);
mode = gtod->clock.vclock_mode;
ns = gtod->nsec_base;
ns += vgettsc(cycle_now);
ns >>= gtod->clock.shift;
ns += gtod->boot_ns;
} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
*t = ns;
return mode;
}
/* returns true if host is using tsc clocksource */
static bool kvm_get_time_and_clockread(s64 *kernel_ns, cycle_t *cycle_now)
{
/* checked again under seqlock below */
if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC)
return false;
return do_monotonic_boot(kernel_ns, cycle_now) == VCLOCK_TSC;
}
#endif
/*
*
* Assuming a stable TSC across physical CPUS, and a stable TSC
* across virtual CPUs, the following condition is possible.
* Each numbered line represents an event visible to both
* CPUs at the next numbered event.
*
* "timespecX" represents host monotonic time. "tscX" represents
* RDTSC value.
*
* VCPU0 on CPU0 | VCPU1 on CPU1
*
* 1. read timespec0,tsc0
* 2. | timespec1 = timespec0 + N
* | tsc1 = tsc0 + M
* 3. transition to guest | transition to guest
* 4. ret0 = timespec0 + (rdtsc - tsc0) |
* 5. | ret1 = timespec1 + (rdtsc - tsc1)
* | ret1 = timespec0 + N + (rdtsc - (tsc0 + M))
*
* Since ret0 update is visible to VCPU1 at time 5, to obey monotonicity:
*
* - ret0 < ret1
* - timespec0 + (rdtsc - tsc0) < timespec0 + N + (rdtsc - (tsc0 + M))
* ...
* - 0 < N - M => M < N
*
* That is, when timespec0 != timespec1, M < N. Unfortunately that is not
* always the case (the difference between two distinct xtime instances
* might be smaller then the difference between corresponding TSC reads,
* when updating guest vcpus pvclock areas).
*
* To avoid that problem, do not allow visibility of distinct
* system_timestamp/tsc_timestamp values simultaneously: use a master
* copy of host monotonic time values. Update that master copy
* in lockstep.
*
* Rely on synchronization of host TSCs and guest TSCs for monotonicity.
*
*/
static void pvclock_update_vm_gtod_copy(struct kvm *kvm)
{
#ifdef CONFIG_X86_64
struct kvm_arch *ka = &kvm->arch;
int vclock_mode;
bool host_tsc_clocksource, vcpus_matched;
vcpus_matched = (ka->nr_vcpus_matched_tsc + 1 ==
atomic_read(&kvm->online_vcpus));
/*
* If the host uses TSC clock, then passthrough TSC as stable
* to the guest.
*/
host_tsc_clocksource = kvm_get_time_and_clockread(
&ka->master_kernel_ns,
&ka->master_cycle_now);
ka->use_master_clock = host_tsc_clocksource && vcpus_matched
&& !backwards_tsc_observed
&& !ka->boot_vcpu_runs_old_kvmclock;
if (ka->use_master_clock)
atomic_set(&kvm_guest_has_master_clock, 1);
vclock_mode = pvclock_gtod_data.clock.vclock_mode;
trace_kvm_update_master_clock(ka->use_master_clock, vclock_mode,
vcpus_matched);
#endif
}
static void kvm_gen_update_masterclock(struct kvm *kvm)
{
#ifdef CONFIG_X86_64
int i;
struct kvm_vcpu *vcpu;
struct kvm_arch *ka = &kvm->arch;
spin_lock(&ka->pvclock_gtod_sync_lock);
kvm_make_mclock_inprogress_request(kvm);
/* no guest entries from this point */
pvclock_update_vm_gtod_copy(kvm);
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
/* guest entries allowed */
kvm_for_each_vcpu(i, vcpu, kvm)
clear_bit(KVM_REQ_MCLOCK_INPROGRESS, &vcpu->requests);
spin_unlock(&ka->pvclock_gtod_sync_lock);
#endif
}
static int kvm_guest_time_update(struct kvm_vcpu *v)
{
unsigned long flags, this_tsc_khz;
struct kvm_vcpu_arch *vcpu = &v->arch;
struct kvm_arch *ka = &v->kvm->arch;
s64 kernel_ns;
u64 tsc_timestamp, host_tsc;
struct pvclock_vcpu_time_info guest_hv_clock;
u8 pvclock_flags;
bool use_master_clock;
kernel_ns = 0;
host_tsc = 0;
/*
* If the host uses TSC clock, then passthrough TSC as stable
* to the guest.
*/
spin_lock(&ka->pvclock_gtod_sync_lock);
use_master_clock = ka->use_master_clock;
if (use_master_clock) {
host_tsc = ka->master_cycle_now;
kernel_ns = ka->master_kernel_ns;
}
spin_unlock(&ka->pvclock_gtod_sync_lock);
/* Keep irq disabled to prevent changes to the clock */
local_irq_save(flags);
x86: Replace __get_cpu_var uses __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Acked-by: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-17 17:30:40 +00:00
this_tsc_khz = __this_cpu_read(cpu_tsc_khz);
if (unlikely(this_tsc_khz == 0)) {
local_irq_restore(flags);
kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
return 1;
}
if (!use_master_clock) {
host_tsc = rdtsc();
kernel_ns = get_kernel_ns();
}
tsc_timestamp = kvm_x86_ops->read_l1_tsc(v, host_tsc);
/*
* We may have to catch up the TSC to match elapsed wall clock
* time for two reasons, even if kvmclock is used.
* 1) CPU could have been running below the maximum TSC rate
* 2) Broken TSC compensation resets the base at each VCPU
* entry to avoid unknown leaps of TSC even when running
* again on the same CPU. This may cause apparent elapsed
* time to disappear, and the guest to stand still or run
* very slowly.
*/
if (vcpu->tsc_catchup) {
u64 tsc = compute_guest_tsc(v, kernel_ns);
if (tsc > tsc_timestamp) {
adjust_tsc_offset_guest(v, tsc - tsc_timestamp);
tsc_timestamp = tsc;
}
}
local_irq_restore(flags);
if (!vcpu->pv_time_enabled)
return 0;
if (unlikely(vcpu->hw_tsc_khz != this_tsc_khz)) {
kvm_get_time_scale(NSEC_PER_SEC / 1000, this_tsc_khz,
&vcpu->hv_clock.tsc_shift,
&vcpu->hv_clock.tsc_to_system_mul);
vcpu->hw_tsc_khz = this_tsc_khz;
}
/* With all the info we got, fill in the values */
vcpu->hv_clock.tsc_timestamp = tsc_timestamp;
vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset;
vcpu->last_guest_tsc = tsc_timestamp;
if (unlikely(kvm_read_guest_cached(v->kvm, &vcpu->pv_time,
&guest_hv_clock, sizeof(guest_hv_clock))))
return 0;
/* This VCPU is paused, but it's legal for a guest to read another
* VCPU's kvmclock, so we really have to follow the specification where
* it says that version is odd if data is being modified, and even after
* it is consistent.
*
* Version field updates must be kept separate. This is because
* kvm_write_guest_cached might use a "rep movs" instruction, and
* writes within a string instruction are weakly ordered. So there
* are three writes overall.
*
* As a small optimization, only write the version field in the first
* and third write. The vcpu->pv_time cache is still valid, because the
* version field is the first in the struct.
*/
BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
vcpu->hv_clock.version = guest_hv_clock.version + 1;
kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
&vcpu->hv_clock,
sizeof(vcpu->hv_clock.version));
smp_wmb();
/* retain PVCLOCK_GUEST_STOPPED if set in guest copy */
pvclock_flags = (guest_hv_clock.flags & PVCLOCK_GUEST_STOPPED);
if (vcpu->pvclock_set_guest_stopped_request) {
pvclock_flags |= PVCLOCK_GUEST_STOPPED;
vcpu->pvclock_set_guest_stopped_request = false;
}
pvclock_flags |= PVCLOCK_COUNTS_FROM_ZERO;
/* If the host uses TSC clocksource, then it is stable */
if (use_master_clock)
pvclock_flags |= PVCLOCK_TSC_STABLE_BIT;
vcpu->hv_clock.flags = pvclock_flags;
trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
&vcpu->hv_clock,
sizeof(vcpu->hv_clock));
smp_wmb();
vcpu->hv_clock.version++;
kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
&vcpu->hv_clock,
sizeof(vcpu->hv_clock.version));
return 0;
}
/*
* kvmclock updates which are isolated to a given vcpu, such as
* vcpu->cpu migration, should not allow system_timestamp from
* the rest of the vcpus to remain static. Otherwise ntp frequency
* correction applies to one vcpu's system_timestamp but not
* the others.
*
* So in those cases, request a kvmclock update for all vcpus.
* We need to rate-limit these requests though, as they can
* considerably slow guests that have a large number of vcpus.
* The time for a remote vcpu to update its kvmclock is bound
* by the delay we use to rate-limit the updates.
*/
#define KVMCLOCK_UPDATE_DELAY msecs_to_jiffies(100)
static void kvmclock_update_fn(struct work_struct *work)
{
int i;
struct delayed_work *dwork = to_delayed_work(work);
struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
kvmclock_update_work);
struct kvm *kvm = container_of(ka, struct kvm, arch);
struct kvm_vcpu *vcpu;
kvm_for_each_vcpu(i, vcpu, kvm) {
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
kvm_vcpu_kick(vcpu);
}
}
static void kvm_gen_kvmclock_update(struct kvm_vcpu *v)
{
struct kvm *kvm = v->kvm;
kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
schedule_delayed_work(&kvm->arch.kvmclock_update_work,
KVMCLOCK_UPDATE_DELAY);
}
#define KVMCLOCK_SYNC_PERIOD (300 * HZ)
static void kvmclock_sync_fn(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
kvmclock_sync_work);
struct kvm *kvm = container_of(ka, struct kvm, arch);
if (!kvmclock_periodic_sync)
return;
schedule_delayed_work(&kvm->arch.kvmclock_update_work, 0);
schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
KVMCLOCK_SYNC_PERIOD);
}
static int set_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
u64 mcg_cap = vcpu->arch.mcg_cap;
unsigned bank_num = mcg_cap & 0xff;
switch (msr) {
case MSR_IA32_MCG_STATUS:
vcpu->arch.mcg_status = data;
break;
case MSR_IA32_MCG_CTL:
if (!(mcg_cap & MCG_CTL_P))
return 1;
if (data != 0 && data != ~(u64)0)
return -1;
vcpu->arch.mcg_ctl = data;
break;
default:
if (msr >= MSR_IA32_MC0_CTL &&
msr < MSR_IA32_MCx_CTL(bank_num)) {
u32 offset = msr - MSR_IA32_MC0_CTL;
/* only 0 or all 1s can be written to IA32_MCi_CTL
* some Linux kernels though clear bit 10 in bank 4 to
* workaround a BIOS/GART TBL issue on AMD K8s, ignore
* this to avoid an uncatched #GP in the guest
*/
if ((offset & 0x3) == 0 &&
data != 0 && (data | (1 << 10)) != ~(u64)0)
return -1;
vcpu->arch.mce_banks[offset] = data;
break;
}
return 1;
}
return 0;
}
static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
{
struct kvm *kvm = vcpu->kvm;
int lm = is_long_mode(vcpu);
u8 *blob_addr = lm ? (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_64
: (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_32;
u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
: kvm->arch.xen_hvm_config.blob_size_32;
u32 page_num = data & ~PAGE_MASK;
u64 page_addr = data & PAGE_MASK;
u8 *page;
int r;
r = -E2BIG;
if (page_num >= blob_size)
goto out;
r = -ENOMEM;
page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE);
if (IS_ERR(page)) {
r = PTR_ERR(page);
goto out;
}
if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE))
goto out_free;
r = 0;
out_free:
kfree(page);
out:
return r;
}
static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
{
gpa_t gpa = data & ~0x3f;
/* Bits 2:5 are reserved, Should be zero */
if (data & 0x3c)
return 1;
vcpu->arch.apf.msr_val = data;
if (!(data & KVM_ASYNC_PF_ENABLED)) {
kvm_clear_async_pf_completion_queue(vcpu);
kvm_async_pf_hash_reset(vcpu);
return 0;
}
if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa,
sizeof(u32)))
return 1;
vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
kvm_async_pf_wakeup_all(vcpu);
return 0;
}
static void kvmclock_reset(struct kvm_vcpu *vcpu)
{
vcpu->arch.pv_time_enabled = false;
}
static void accumulate_steal_time(struct kvm_vcpu *vcpu)
{
u64 delta;
if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
return;
delta = current->sched_info.run_delay - vcpu->arch.st.last_steal;
vcpu->arch.st.last_steal = current->sched_info.run_delay;
vcpu->arch.st.accum_steal = delta;
}
static void record_steal_time(struct kvm_vcpu *vcpu)
{
if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
return;
if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
&vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
return;
vcpu->arch.st.steal.steal += vcpu->arch.st.accum_steal;
vcpu->arch.st.steal.version += 2;
vcpu->arch.st.accum_steal = 0;
kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
}
int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
bool pr = false;
u32 msr = msr_info->index;
u64 data = msr_info->data;
switch (msr) {
case MSR_AMD64_NB_CFG:
case MSR_IA32_UCODE_REV:
case MSR_IA32_UCODE_WRITE:
case MSR_VM_HSAVE_PA:
case MSR_AMD64_PATCH_LOADER:
case MSR_AMD64_BU_CFG2:
break;
case MSR_EFER:
return set_efer(vcpu, data);
case MSR_K7_HWCR:
data &= ~(u64)0x40; /* ignore flush filter disable */
data &= ~(u64)0x100; /* ignore ignne emulation enable */
data &= ~(u64)0x8; /* ignore TLB cache disable */
data &= ~(u64)0x40000; /* ignore Mc status write enable */
if (data != 0) {
vcpu_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
data);
return 1;
}
break;
case MSR_FAM10H_MMIO_CONF_BASE:
if (data != 0) {
vcpu_unimpl(vcpu, "unimplemented MMIO_CONF_BASE wrmsr: "
"0x%llx\n", data);
return 1;
}
break;
case MSR_IA32_DEBUGCTLMSR:
if (!data) {
/* We support the non-activated case already */
break;
} else if (data & ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF)) {
/* Values other than LBR and BTF are vendor-specific,
thus reserved and should throw a #GP */
return 1;
}
vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
__func__, data);
break;
case 0x200 ... 0x2ff:
return kvm_mtrr_set_msr(vcpu, msr, data);
case MSR_IA32_APICBASE:
return kvm_set_apic_base(vcpu, msr_info);
case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
return kvm_x2apic_msr_write(vcpu, msr, data);
case MSR_IA32_TSCDEADLINE:
kvm_set_lapic_tscdeadline_msr(vcpu, data);
break;
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
case MSR_IA32_TSC_ADJUST:
if (guest_cpuid_has_tsc_adjust(vcpu)) {
if (!msr_info->host_initiated) {
s64 adj = data - vcpu->arch.ia32_tsc_adjust_msr;
adjust_tsc_offset_guest(vcpu, adj);
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
}
vcpu->arch.ia32_tsc_adjust_msr = data;
}
break;
case MSR_IA32_MISC_ENABLE:
vcpu->arch.ia32_misc_enable_msr = data;
break;
case MSR_IA32_SMBASE:
if (!msr_info->host_initiated)
return 1;
vcpu->arch.smbase = data;
break;
case MSR_KVM_WALL_CLOCK_NEW:
case MSR_KVM_WALL_CLOCK:
vcpu->kvm->arch.wall_clock = data;
kvm_write_wall_clock(vcpu->kvm, data);
break;
case MSR_KVM_SYSTEM_TIME_NEW:
case MSR_KVM_SYSTEM_TIME: {
u64 gpa_offset;
struct kvm_arch *ka = &vcpu->kvm->arch;
kvmclock_reset(vcpu);
if (vcpu->vcpu_id == 0 && !msr_info->host_initiated) {
bool tmp = (msr == MSR_KVM_SYSTEM_TIME);
if (ka->boot_vcpu_runs_old_kvmclock != tmp)
set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
&vcpu->requests);
ka->boot_vcpu_runs_old_kvmclock = tmp;
ka->kvmclock_offset = -get_kernel_ns();
}
vcpu->arch.time = data;
kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);
/* we verify if the enable bit is set... */
if (!(data & 1))
break;
gpa_offset = data & ~(PAGE_MASK | 1);
if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
&vcpu->arch.pv_time, data & ~1ULL,
sizeof(struct pvclock_vcpu_time_info)))
vcpu->arch.pv_time_enabled = false;
else
vcpu->arch.pv_time_enabled = true;
break;
}
case MSR_KVM_ASYNC_PF_EN:
if (kvm_pv_enable_async_pf(vcpu, data))
return 1;
break;
case MSR_KVM_STEAL_TIME:
if (unlikely(!sched_info_on()))
return 1;
if (data & KVM_STEAL_RESERVED_MASK)
return 1;
if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.st.stime,
data & KVM_STEAL_VALID_BITS,
sizeof(struct kvm_steal_time)))
return 1;
vcpu->arch.st.msr_val = data;
if (!(data & KVM_MSR_ENABLED))
break;
vcpu->arch.st.last_steal = current->sched_info.run_delay;
preempt_disable();
accumulate_steal_time(vcpu);
preempt_enable();
kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
break;
case MSR_KVM_PV_EOI_EN:
if (kvm_lapic_enable_pv_eoi(vcpu, data))
return 1;
break;
case MSR_IA32_MCG_CTL:
case MSR_IA32_MCG_STATUS:
case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
return set_msr_mce(vcpu, msr, data);
case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1:
pr = true; /* fall through */
case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL1:
if (kvm_pmu_is_valid_msr(vcpu, msr))
return kvm_pmu_set_msr(vcpu, msr_info);
if (pr || data != 0)
vcpu_unimpl(vcpu, "disabled perfctr wrmsr: "
"0x%x data 0x%llx\n", msr, data);
break;
case MSR_K7_CLK_CTL:
/*
* Ignore all writes to this no longer documented MSR.
* Writes are only relevant for old K7 processors,
* all pre-dating SVM, but a recommended workaround from
* AMD for these chips. It is possible to specify the
* affected processor models on the command line, hence
* the need to ignore the workaround.
*/
break;
case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
case HV_X64_MSR_CRASH_CTL:
return kvm_hv_set_msr_common(vcpu, msr, data,
msr_info->host_initiated);
case MSR_IA32_BBL_CR_CTL3:
/* Drop writes to this legacy MSR -- see rdmsr
* counterpart for further detail.
*/
vcpu_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n", msr, data);
break;
case MSR_AMD64_OSVW_ID_LENGTH:
if (!guest_cpuid_has_osvw(vcpu))
return 1;
vcpu->arch.osvw.length = data;
break;
case MSR_AMD64_OSVW_STATUS:
if (!guest_cpuid_has_osvw(vcpu))
return 1;
vcpu->arch.osvw.status = data;
break;
default:
if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr))
return xen_hvm_config(vcpu, data);
if (kvm_pmu_is_valid_msr(vcpu, msr))
return kvm_pmu_set_msr(vcpu, msr_info);
if (!ignore_msrs) {
vcpu_unimpl(vcpu, "unhandled wrmsr: 0x%x data %llx\n",
msr, data);
return 1;
} else {
vcpu_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n",
msr, data);
break;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_msr_common);
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
* Assumes vcpu_load() was already called.
*/
int kvm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
return kvm_x86_ops->get_msr(vcpu, msr);
}
EXPORT_SYMBOL_GPL(kvm_get_msr);
static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
u64 data;
u64 mcg_cap = vcpu->arch.mcg_cap;
unsigned bank_num = mcg_cap & 0xff;
switch (msr) {
case MSR_IA32_P5_MC_ADDR:
case MSR_IA32_P5_MC_TYPE:
data = 0;
break;
case MSR_IA32_MCG_CAP:
data = vcpu->arch.mcg_cap;
break;
case MSR_IA32_MCG_CTL:
if (!(mcg_cap & MCG_CTL_P))
return 1;
data = vcpu->arch.mcg_ctl;
break;
case MSR_IA32_MCG_STATUS:
data = vcpu->arch.mcg_status;
break;
default:
if (msr >= MSR_IA32_MC0_CTL &&
msr < MSR_IA32_MCx_CTL(bank_num)) {
u32 offset = msr - MSR_IA32_MC0_CTL;
data = vcpu->arch.mce_banks[offset];
break;
}
return 1;
}
*pdata = data;
return 0;
}
int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
switch (msr_info->index) {
case MSR_IA32_PLATFORM_ID:
case MSR_IA32_EBL_CR_POWERON:
case MSR_IA32_DEBUGCTLMSR:
case MSR_IA32_LASTBRANCHFROMIP:
case MSR_IA32_LASTBRANCHTOIP:
case MSR_IA32_LASTINTFROMIP:
case MSR_IA32_LASTINTTOIP:
case MSR_K8_SYSCFG:
case MSR_K7_HWCR:
case MSR_VM_HSAVE_PA:
case MSR_K8_INT_PENDING_MSG:
case MSR_AMD64_NB_CFG:
case MSR_FAM10H_MMIO_CONF_BASE:
case MSR_AMD64_BU_CFG2:
msr_info->data = 0;
break;
case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1:
case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL1:
if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
return kvm_pmu_get_msr(vcpu, msr_info->index, &msr_info->data);
msr_info->data = 0;
break;
case MSR_IA32_UCODE_REV:
msr_info->data = 0x100000000ULL;
break;
case MSR_MTRRcap:
case 0x200 ... 0x2ff:
return kvm_mtrr_get_msr(vcpu, msr_info->index, &msr_info->data);
case 0xcd: /* fsb frequency */
msr_info->data = 3;
break;
/*
* MSR_EBC_FREQUENCY_ID
* Conservative value valid for even the basic CPU models.
* Models 0,1: 000 in bits 23:21 indicating a bus speed of
* 100MHz, model 2 000 in bits 18:16 indicating 100MHz,
* and 266MHz for model 3, or 4. Set Core Clock
* Frequency to System Bus Frequency Ratio to 1 (bits
* 31:24) even though these are only valid for CPU
* models > 2, however guests may end up dividing or
* multiplying by zero otherwise.
*/
case MSR_EBC_FREQUENCY_ID:
msr_info->data = 1 << 24;
break;
case MSR_IA32_APICBASE:
msr_info->data = kvm_get_apic_base(vcpu);
break;
case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
return kvm_x2apic_msr_read(vcpu, msr_info->index, &msr_info->data);
break;
case MSR_IA32_TSCDEADLINE:
msr_info->data = kvm_get_lapic_tscdeadline_msr(vcpu);
break;
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
case MSR_IA32_TSC_ADJUST:
msr_info->data = (u64)vcpu->arch.ia32_tsc_adjust_msr;
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
break;
case MSR_IA32_MISC_ENABLE:
msr_info->data = vcpu->arch.ia32_misc_enable_msr;
break;
case MSR_IA32_SMBASE:
if (!msr_info->host_initiated)
return 1;
msr_info->data = vcpu->arch.smbase;
break;
case MSR_IA32_PERF_STATUS:
/* TSC increment by tick */
msr_info->data = 1000ULL;
/* CPU multiplier */
msr_info->data |= (((uint64_t)4ULL) << 40);
break;
case MSR_EFER:
msr_info->data = vcpu->arch.efer;
break;
case MSR_KVM_WALL_CLOCK:
case MSR_KVM_WALL_CLOCK_NEW:
msr_info->data = vcpu->kvm->arch.wall_clock;
break;
case MSR_KVM_SYSTEM_TIME:
case MSR_KVM_SYSTEM_TIME_NEW:
msr_info->data = vcpu->arch.time;
break;
case MSR_KVM_ASYNC_PF_EN:
msr_info->data = vcpu->arch.apf.msr_val;
break;
case MSR_KVM_STEAL_TIME:
msr_info->data = vcpu->arch.st.msr_val;
break;
case MSR_KVM_PV_EOI_EN:
msr_info->data = vcpu->arch.pv_eoi.msr_val;
break;
case MSR_IA32_P5_MC_ADDR:
case MSR_IA32_P5_MC_TYPE:
case MSR_IA32_MCG_CAP:
case MSR_IA32_MCG_CTL:
case MSR_IA32_MCG_STATUS:
case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
return get_msr_mce(vcpu, msr_info->index, &msr_info->data);
case MSR_K7_CLK_CTL:
/*
* Provide expected ramp-up count for K7. All other
* are set to zero, indicating minimum divisors for
* every field.
*
* This prevents guest kernels on AMD host with CPU
* type 6, model 8 and higher from exploding due to
* the rdmsr failing.
*/
msr_info->data = 0x20000000;
break;
case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
case HV_X64_MSR_CRASH_CTL:
return kvm_hv_get_msr_common(vcpu,
msr_info->index, &msr_info->data);
break;
case MSR_IA32_BBL_CR_CTL3:
/* This legacy MSR exists but isn't fully documented in current
* silicon. It is however accessed by winxp in very narrow
* scenarios where it sets bit #19, itself documented as
* a "reserved" bit. Best effort attempt to source coherent
* read data here should the balance of the register be
* interpreted by the guest:
*
* L2 cache control register 3: 64GB range, 256KB size,
* enabled, latency 0x1, configured
*/
msr_info->data = 0xbe702111;
break;
case MSR_AMD64_OSVW_ID_LENGTH:
if (!guest_cpuid_has_osvw(vcpu))
return 1;
msr_info->data = vcpu->arch.osvw.length;
break;
case MSR_AMD64_OSVW_STATUS:
if (!guest_cpuid_has_osvw(vcpu))
return 1;
msr_info->data = vcpu->arch.osvw.status;
break;
default:
if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
return kvm_pmu_get_msr(vcpu, msr_info->index, &msr_info->data);
if (!ignore_msrs) {
vcpu_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr_info->index);
return 1;
} else {
vcpu_unimpl(vcpu, "ignored rdmsr: 0x%x\n", msr_info->index);
msr_info->data = 0;
}
break;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_get_msr_common);
/*
* Read or write a bunch of msrs. All parameters are kernel addresses.
*
* @return number of msrs set successfully.
*/
static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
struct kvm_msr_entry *entries,
int (*do_msr)(struct kvm_vcpu *vcpu,
unsigned index, u64 *data))
{
int i, idx;
idx = srcu_read_lock(&vcpu->kvm->srcu);
for (i = 0; i < msrs->nmsrs; ++i)
if (do_msr(vcpu, entries[i].index, &entries[i].data))
break;
srcu_read_unlock(&vcpu->kvm->srcu, idx);
return i;
}
/*
* Read or write a bunch of msrs. Parameters are user addresses.
*
* @return number of msrs set successfully.
*/
static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
int (*do_msr)(struct kvm_vcpu *vcpu,
unsigned index, u64 *data),
int writeback)
{
struct kvm_msrs msrs;
struct kvm_msr_entry *entries;
int r, n;
unsigned size;
r = -EFAULT;
if (copy_from_user(&msrs, user_msrs, sizeof msrs))
goto out;
r = -E2BIG;
if (msrs.nmsrs >= MAX_IO_MSRS)
goto out;
size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
entries = memdup_user(user_msrs->entries, size);
if (IS_ERR(entries)) {
r = PTR_ERR(entries);
goto out;
}
r = n = __msr_io(vcpu, &msrs, entries, do_msr);
if (r < 0)
goto out_free;
r = -EFAULT;
if (writeback && copy_to_user(user_msrs->entries, entries, size))
goto out_free;
r = n;
out_free:
kfree(entries);
out:
return r;
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r;
switch (ext) {
case KVM_CAP_IRQCHIP:
case KVM_CAP_HLT:
case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
case KVM_CAP_SET_TSS_ADDR:
case KVM_CAP_EXT_CPUID:
case KVM_CAP_EXT_EMUL_CPUID:
case KVM_CAP_CLOCKSOURCE:
case KVM_CAP_PIT:
case KVM_CAP_NOP_IO_DELAY:
case KVM_CAP_MP_STATE:
case KVM_CAP_SYNC_MMU:
case KVM_CAP_USER_NMI:
case KVM_CAP_REINJECT_CONTROL:
case KVM_CAP_IRQ_INJECT_STATUS:
KVM: add ioeventfd support ioeventfd is a mechanism to register PIO/MMIO regions to trigger an eventfd signal when written to by a guest. Host userspace can register any arbitrary IO address with a corresponding eventfd and then pass the eventfd to a specific end-point of interest for handling. Normal IO requires a blocking round-trip since the operation may cause side-effects in the emulated model or may return data to the caller. Therefore, an IO in KVM traps from the guest to the host, causes a VMX/SVM "heavy-weight" exit back to userspace, and is ultimately serviced by qemu's device model synchronously before returning control back to the vcpu. However, there is a subclass of IO which acts purely as a trigger for other IO (such as to kick off an out-of-band DMA request, etc). For these patterns, the synchronous call is particularly expensive since we really only want to simply get our notification transmitted asychronously and return as quickly as possible. All the sychronous infrastructure to ensure proper data-dependencies are met in the normal IO case are just unecessary overhead for signalling. This adds additional computational load on the system, as well as latency to the signalling path. Therefore, we provide a mechanism for registration of an in-kernel trigger point that allows the VCPU to only require a very brief, lightweight exit just long enough to signal an eventfd. This also means that any clients compatible with the eventfd interface (which includes userspace and kernelspace equally well) can now register to be notified. The end result should be a more flexible and higher performance notification API for the backend KVM hypervisor and perhipheral components. To test this theory, we built a test-harness called "doorbell". This module has a function called "doorbell_ring()" which simply increments a counter for each time the doorbell is signaled. It supports signalling from either an eventfd, or an ioctl(). We then wired up two paths to the doorbell: One via QEMU via a registered io region and through the doorbell ioctl(). The other is direct via ioeventfd. You can download this test harness here: ftp://ftp.novell.com/dev/ghaskins/doorbell.tar.bz2 The measured results are as follows: qemu-mmio: 110000 iops, 9.09us rtt ioeventfd-mmio: 200100 iops, 5.00us rtt ioeventfd-pio: 367300 iops, 2.72us rtt I didn't measure qemu-pio, because I have to figure out how to register a PIO region with qemu's device model, and I got lazy. However, for now we can extrapolate based on the data from the NULLIO runs of +2.56us for MMIO, and -350ns for HC, we get: qemu-pio: 153139 iops, 6.53us rtt ioeventfd-hc: 412585 iops, 2.37us rtt these are just for fun, for now, until I can gather more data. Here is a graph for your convenience: http://developer.novell.com/wiki/images/7/76/Iofd-chart.png The conclusion to draw is that we save about 4us by skipping the userspace hop. -------------------- Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-07-07 21:08:49 +00:00
case KVM_CAP_IOEVENTFD:
case KVM_CAP_IOEVENTFD_NO_LENGTH:
case KVM_CAP_PIT2:
case KVM_CAP_PIT_STATE2:
case KVM_CAP_SET_IDENTITY_MAP_ADDR:
case KVM_CAP_XEN_HVM:
case KVM_CAP_ADJUST_CLOCK:
case KVM_CAP_VCPU_EVENTS:
case KVM_CAP_HYPERV:
case KVM_CAP_HYPERV_VAPIC:
case KVM_CAP_HYPERV_SPIN:
case KVM_CAP_PCI_SEGMENT:
case KVM_CAP_DEBUGREGS:
case KVM_CAP_X86_ROBUST_SINGLESTEP:
case KVM_CAP_XSAVE:
case KVM_CAP_ASYNC_PF:
case KVM_CAP_GET_TSC_KHZ:
case KVM_CAP_KVMCLOCK_CTRL:
case KVM_CAP_READONLY_MEM:
case KVM_CAP_HYPERV_TIME:
case KVM_CAP_IOAPIC_POLARITY_IGNORED:
case KVM_CAP_TSC_DEADLINE_TIMER:
case KVM_CAP_ENABLE_CAP_VM:
case KVM_CAP_DISABLE_QUIRKS:
case KVM_CAP_SET_BOOT_CPU_ID:
#ifdef CONFIG_KVM_DEVICE_ASSIGNMENT
case KVM_CAP_ASSIGN_DEV_IRQ:
case KVM_CAP_PCI_2_3:
#endif
r = 1;
break;
case KVM_CAP_X86_SMM:
/* SMBASE is usually relocated above 1M on modern chipsets,
* and SMM handlers might indeed rely on 4G segment limits,
* so do not report SMM to be available if real mode is
* emulated via vm86 mode. Still, do not go to great lengths
* to avoid userspace's usage of the feature, because it is a
* fringe case that is not enabled except via specific settings
* of the module parameters.
*/
r = kvm_x86_ops->cpu_has_high_real_mode_segbase();
break;
case KVM_CAP_COALESCED_MMIO:
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
break;
case KVM_CAP_VAPIC:
r = !kvm_x86_ops->cpu_has_accelerated_tpr();
break;
case KVM_CAP_NR_VCPUS:
r = KVM_SOFT_MAX_VCPUS;
break;
case KVM_CAP_MAX_VCPUS:
r = KVM_MAX_VCPUS;
break;
case KVM_CAP_NR_MEMSLOTS:
r = KVM_USER_MEM_SLOTS;
break;
case KVM_CAP_PV_MMU: /* obsolete */
r = 0;
break;
#ifdef CONFIG_KVM_DEVICE_ASSIGNMENT
case KVM_CAP_IOMMU:
r = iommu_present(&pci_bus_type);
break;
#endif
case KVM_CAP_MCE:
r = KVM_MAX_MCE_BANKS;
break;
case KVM_CAP_XCRS:
r = cpu_has_xsave;
break;
case KVM_CAP_TSC_CONTROL:
r = kvm_has_tsc_control;
break;
default:
r = 0;
break;
}
return r;
}
long kvm_arch_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
void __user *argp = (void __user *)arg;
long r;
switch (ioctl) {
case KVM_GET_MSR_INDEX_LIST: {
struct kvm_msr_list __user *user_msr_list = argp;
struct kvm_msr_list msr_list;
unsigned n;
r = -EFAULT;
if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
goto out;
n = msr_list.nmsrs;
msr_list.nmsrs = num_msrs_to_save + num_emulated_msrs;
if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
goto out;
r = -E2BIG;
if (n < msr_list.nmsrs)
goto out;
r = -EFAULT;
if (copy_to_user(user_msr_list->indices, &msrs_to_save,
num_msrs_to_save * sizeof(u32)))
goto out;
if (copy_to_user(user_msr_list->indices + num_msrs_to_save,
&emulated_msrs,
num_emulated_msrs * sizeof(u32)))
goto out;
r = 0;
break;
}
case KVM_GET_SUPPORTED_CPUID:
case KVM_GET_EMULATED_CPUID: {
struct kvm_cpuid2 __user *cpuid_arg = argp;
struct kvm_cpuid2 cpuid;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
goto out;
r = kvm_dev_ioctl_get_cpuid(&cpuid, cpuid_arg->entries,
ioctl);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
goto out;
r = 0;
break;
}
case KVM_X86_GET_MCE_CAP_SUPPORTED: {
u64 mce_cap;
mce_cap = KVM_MCE_CAP_SUPPORTED;
r = -EFAULT;
if (copy_to_user(argp, &mce_cap, sizeof mce_cap))
goto out;
r = 0;
break;
}
default:
r = -EINVAL;
}
out:
return r;
}
static void wbinvd_ipi(void *garbage)
{
wbinvd();
}
static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)
{
return kvm_arch_has_noncoherent_dma(vcpu->kvm);
}
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
/* Address WBINVD may be executed by guest */
if (need_emulate_wbinvd(vcpu)) {
if (kvm_x86_ops->has_wbinvd_exit())
cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
smp_call_function_single(vcpu->cpu,
wbinvd_ipi, NULL, 1);
}
kvm_x86_ops->vcpu_load(vcpu, cpu);
/* Apply any externally detected TSC adjustments (due to suspend) */
if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
vcpu->arch.tsc_offset_adjustment = 0;
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
}
if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
rdtsc() - vcpu->arch.last_host_tsc;
if (tsc_delta < 0)
mark_tsc_unstable("KVM discovered backwards TSC");
if (check_tsc_unstable()) {
u64 offset = kvm_x86_ops->compute_tsc_offset(vcpu,
vcpu->arch.last_guest_tsc);
kvm_x86_ops->write_tsc_offset(vcpu, offset);
vcpu->arch.tsc_catchup = 1;
}
/*
* On a host with synchronized TSC, there is no need to update
* kvmclock on vcpu->cpu migration
*/
if (!vcpu->kvm->arch.use_master_clock || vcpu->cpu == -1)
kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);
if (vcpu->cpu != cpu)
kvm_migrate_timers(vcpu);
vcpu->cpu = cpu;
}
accumulate_steal_time(vcpu);
kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->vcpu_put(vcpu);
kvm_put_guest_fpu(vcpu);
vcpu->arch.last_host_tsc = rdtsc();
}
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
kvm_x86_ops->sync_pir_to_irr(vcpu);
memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s);
return 0;
}
static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
kvm_apic_post_state_restore(vcpu, s);
update_cr8_intercept(vcpu);
return 0;
}
static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
struct kvm_interrupt *irq)
{
if (irq->irq >= KVM_NR_INTERRUPTS)
return -EINVAL;
if (irqchip_in_kernel(vcpu->kvm))
return -ENXIO;
kvm_queue_interrupt(vcpu, irq->irq, false);
kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
{
kvm_inject_nmi(vcpu);
return 0;
}
static int kvm_vcpu_ioctl_smi(struct kvm_vcpu *vcpu)
{
kvm_make_request(KVM_REQ_SMI, vcpu);
return 0;
}
static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
struct kvm_tpr_access_ctl *tac)
{
if (tac->flags)
return -EINVAL;
vcpu->arch.tpr_access_reporting = !!tac->enabled;
return 0;
}
static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
u64 mcg_cap)
{
int r;
unsigned bank_num = mcg_cap & 0xff, bank;
r = -EINVAL;
if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS)
goto out;
if (mcg_cap & ~(KVM_MCE_CAP_SUPPORTED | 0xff | 0xff0000))
goto out;
r = 0;
vcpu->arch.mcg_cap = mcg_cap;
/* Init IA32_MCG_CTL to all 1s */
if (mcg_cap & MCG_CTL_P)
vcpu->arch.mcg_ctl = ~(u64)0;
/* Init IA32_MCi_CTL to all 1s */
for (bank = 0; bank < bank_num; bank++)
vcpu->arch.mce_banks[bank*4] = ~(u64)0;
out:
return r;
}
static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
struct kvm_x86_mce *mce)
{
u64 mcg_cap = vcpu->arch.mcg_cap;
unsigned bank_num = mcg_cap & 0xff;
u64 *banks = vcpu->arch.mce_banks;
if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL))
return -EINVAL;
/*
* if IA32_MCG_CTL is not all 1s, the uncorrected error
* reporting is disabled
*/
if ((mce->status & MCI_STATUS_UC) && (mcg_cap & MCG_CTL_P) &&
vcpu->arch.mcg_ctl != ~(u64)0)
return 0;
banks += 4 * mce->bank;
/*
* if IA32_MCi_CTL is not all 1s, the uncorrected error
* reporting is disabled for the bank
*/
if ((mce->status & MCI_STATUS_UC) && banks[0] != ~(u64)0)
return 0;
if (mce->status & MCI_STATUS_UC) {
if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
!kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
return 0;
}
if (banks[1] & MCI_STATUS_VAL)
mce->status |= MCI_STATUS_OVER;
banks[2] = mce->addr;
banks[3] = mce->misc;
vcpu->arch.mcg_status = mce->mcg_status;
banks[1] = mce->status;
kvm_queue_exception(vcpu, MC_VECTOR);
} else if (!(banks[1] & MCI_STATUS_VAL)
|| !(banks[1] & MCI_STATUS_UC)) {
if (banks[1] & MCI_STATUS_VAL)
mce->status |= MCI_STATUS_OVER;
banks[2] = mce->addr;
banks[3] = mce->misc;
banks[1] = mce->status;
} else
banks[1] |= MCI_STATUS_OVER;
return 0;
}
static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
struct kvm_vcpu_events *events)
{
process_nmi(vcpu);
events->exception.injected =
vcpu->arch.exception.pending &&
!kvm_exception_is_soft(vcpu->arch.exception.nr);
events->exception.nr = vcpu->arch.exception.nr;
events->exception.has_error_code = vcpu->arch.exception.has_error_code;
events->exception.pad = 0;
events->exception.error_code = vcpu->arch.exception.error_code;
events->interrupt.injected =
vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft;
events->interrupt.nr = vcpu->arch.interrupt.nr;
events->interrupt.soft = 0;
events->interrupt.shadow = kvm_x86_ops->get_interrupt_shadow(vcpu);
events->nmi.injected = vcpu->arch.nmi_injected;
events->nmi.pending = vcpu->arch.nmi_pending != 0;
events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu);
events->nmi.pad = 0;
events->sipi_vector = 0; /* never valid when reporting to user space */
events->smi.smm = is_smm(vcpu);
events->smi.pending = vcpu->arch.smi_pending;
events->smi.smm_inside_nmi =
!!(vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK);
events->smi.latched_init = kvm_lapic_latched_init(vcpu);
events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
| KVM_VCPUEVENT_VALID_SHADOW
| KVM_VCPUEVENT_VALID_SMM);
memset(&events->reserved, 0, sizeof(events->reserved));
}
static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
struct kvm_vcpu_events *events)
{
if (events->flags & ~(KVM_VCPUEVENT_VALID_NMI_PENDING
| KVM_VCPUEVENT_VALID_SIPI_VECTOR
| KVM_VCPUEVENT_VALID_SHADOW
| KVM_VCPUEVENT_VALID_SMM))
return -EINVAL;
process_nmi(vcpu);
vcpu->arch.exception.pending = events->exception.injected;
vcpu->arch.exception.nr = events->exception.nr;
vcpu->arch.exception.has_error_code = events->exception.has_error_code;
vcpu->arch.exception.error_code = events->exception.error_code;
vcpu->arch.interrupt.pending = events->interrupt.injected;
vcpu->arch.interrupt.nr = events->interrupt.nr;
vcpu->arch.interrupt.soft = events->interrupt.soft;
if (events->flags & KVM_VCPUEVENT_VALID_SHADOW)
kvm_x86_ops->set_interrupt_shadow(vcpu,
events->interrupt.shadow);
vcpu->arch.nmi_injected = events->nmi.injected;
if (events->flags & KVM_VCPUEVENT_VALID_NMI_PENDING)
vcpu->arch.nmi_pending = events->nmi.pending;
kvm_x86_ops->set_nmi_mask(vcpu, events->nmi.masked);
if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR &&
kvm_vcpu_has_lapic(vcpu))
vcpu->arch.apic->sipi_vector = events->sipi_vector;
if (events->flags & KVM_VCPUEVENT_VALID_SMM) {
if (events->smi.smm)
vcpu->arch.hflags |= HF_SMM_MASK;
else
vcpu->arch.hflags &= ~HF_SMM_MASK;
vcpu->arch.smi_pending = events->smi.pending;
if (events->smi.smm_inside_nmi)
vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
else
vcpu->arch.hflags &= ~HF_SMM_INSIDE_NMI_MASK;
if (kvm_vcpu_has_lapic(vcpu)) {
if (events->smi.latched_init)
set_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
else
clear_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
}
}
kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
struct kvm_debugregs *dbgregs)
{
unsigned long val;
memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
kvm_get_dr(vcpu, 6, &val);
dbgregs->dr6 = val;
dbgregs->dr7 = vcpu->arch.dr7;
dbgregs->flags = 0;
memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
}
static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
struct kvm_debugregs *dbgregs)
{
if (dbgregs->flags)
return -EINVAL;
memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db));
kvm_update_dr0123(vcpu);
vcpu->arch.dr6 = dbgregs->dr6;
kvm_update_dr6(vcpu);
vcpu->arch.dr7 = dbgregs->dr7;
kvm_update_dr7(vcpu);
return 0;
}
#define XSTATE_COMPACTION_ENABLED (1ULL << 63)
static void fill_xsave(u8 *dest, struct kvm_vcpu *vcpu)
{
struct xregs_state *xsave = &vcpu->arch.guest_fpu.state.xsave;
u64 xstate_bv = xsave->header.xfeatures;
u64 valid;
/*
* Copy legacy XSAVE area, to avoid complications with CPUID
* leaves 0 and 1 in the loop below.
*/
memcpy(dest, xsave, XSAVE_HDR_OFFSET);
/* Set XSTATE_BV */
*(u64 *)(dest + XSAVE_HDR_OFFSET) = xstate_bv;
/*
* Copy each region from the possibly compacted offset to the
* non-compacted offset.
*/
valid = xstate_bv & ~XSTATE_FPSSE;
while (valid) {
u64 feature = valid & -valid;
int index = fls64(feature) - 1;
void *src = get_xsave_addr(xsave, feature);
if (src) {
u32 size, offset, ecx, edx;
cpuid_count(XSTATE_CPUID, index,
&size, &offset, &ecx, &edx);
memcpy(dest + offset, src, size);
}
valid -= feature;
}
}
static void load_xsave(struct kvm_vcpu *vcpu, u8 *src)
{
struct xregs_state *xsave = &vcpu->arch.guest_fpu.state.xsave;
u64 xstate_bv = *(u64 *)(src + XSAVE_HDR_OFFSET);
u64 valid;
/*
* Copy legacy XSAVE area, to avoid complications with CPUID
* leaves 0 and 1 in the loop below.
*/
memcpy(xsave, src, XSAVE_HDR_OFFSET);
/* Set XSTATE_BV and possibly XCOMP_BV. */
xsave->header.xfeatures = xstate_bv;
if (cpu_has_xsaves)
xsave->header.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED;
/*
* Copy each region from the non-compacted offset to the
* possibly compacted offset.
*/
valid = xstate_bv & ~XSTATE_FPSSE;
while (valid) {
u64 feature = valid & -valid;
int index = fls64(feature) - 1;
void *dest = get_xsave_addr(xsave, feature);
if (dest) {
u32 size, offset, ecx, edx;
cpuid_count(XSTATE_CPUID, index,
&size, &offset, &ecx, &edx);
memcpy(dest, src + offset, size);
kvm: x86: fix load xsave feature warning [ 68.196974] WARNING: CPU: 1 PID: 2140 at arch/x86/kvm/x86.c:3161 kvm_arch_vcpu_ioctl+0xe88/0x1340 [kvm]() [ 68.196975] Modules linked in: snd_hda_codec_hdmi i915 rfcomm bnep bluetooth i2c_algo_bit rfkill nfsd drm_kms_helper nfs_acl nfs drm lockd grace sunrpc fscache snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_dummy snd_seq_oss x86_pkg_temp_thermal snd_seq_midi kvm_intel snd_seq_midi_event snd_rawmidi kvm snd_seq ghash_clmulni_intel fuse snd_timer aesni_intel parport_pc ablk_helper snd_seq_device cryptd ppdev snd lp parport lrw dcdbas gf128mul i2c_core glue_helper lpc_ich video shpchp mfd_core soundcore serio_raw acpi_cpufreq ext4 mbcache jbd2 sd_mod crc32c_intel ahci libahci libata e1000e ptp pps_core [ 68.197005] CPU: 1 PID: 2140 Comm: qemu-system-x86 Not tainted 4.2.0-rc1+ #2 [ 68.197006] Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015 [ 68.197007] ffffffffa03b0657 ffff8800d984bca8 ffffffff815915a2 0000000000000000 [ 68.197009] 0000000000000000 ffff8800d984bce8 ffffffff81057c0a 00007ff6d0001000 [ 68.197010] 0000000000000002 ffff880211c1a000 0000000000000004 ffff8800ce0288c0 [ 68.197012] Call Trace: [ 68.197017] [<ffffffff815915a2>] dump_stack+0x45/0x57 [ 68.197020] [<ffffffff81057c0a>] warn_slowpath_common+0x8a/0xc0 [ 68.197022] [<ffffffff81057cfa>] warn_slowpath_null+0x1a/0x20 [ 68.197029] [<ffffffffa037bed8>] kvm_arch_vcpu_ioctl+0xe88/0x1340 [kvm] [ 68.197035] [<ffffffffa037aede>] ? kvm_arch_vcpu_load+0x4e/0x1c0 [kvm] [ 68.197040] [<ffffffffa03696a6>] kvm_vcpu_ioctl+0xc6/0x5c0 [kvm] [ 68.197043] [<ffffffff811252d2>] ? perf_pmu_enable+0x22/0x30 [ 68.197044] [<ffffffff8112663e>] ? perf_event_context_sched_in+0x7e/0xb0 [ 68.197048] [<ffffffff811a6882>] do_vfs_ioctl+0x2c2/0x4a0 [ 68.197050] [<ffffffff8107bf33>] ? finish_task_switch+0x173/0x220 [ 68.197053] [<ffffffff8123307f>] ? selinux_file_ioctl+0x4f/0xd0 [ 68.197055] [<ffffffff8122cac3>] ? security_file_ioctl+0x43/0x60 [ 68.197057] [<ffffffff811a6ad9>] SyS_ioctl+0x79/0x90 [ 68.197060] [<ffffffff81597e57>] entry_SYSCALL_64_fastpath+0x12/0x6a [ 68.197061] ---[ end trace 558a5ebf9445fc80 ]--- After commit (0c4109bec0 'x86/fpu/xstate: Fix up bad get_xsave_addr() assumptions'), there is no assumption an xsave bit is present in the hardware (pcntxt_mask) that it is always present in a given xsave buffer. An enabled state to be present on 'pcntxt_mask', but *not* in 'xstate_bv' could happen when the last 'xsave' did not request that this feature be saved (unlikely) or because the "init optimization" caused it to not be saved. This patch kill the assumption. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-09 07:44:52 +00:00
}
valid -= feature;
}
}
static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
struct kvm_xsave *guest_xsave)
{
if (cpu_has_xsave) {
memset(guest_xsave, 0, sizeof(struct kvm_xsave));
fill_xsave((u8 *) guest_xsave->region, vcpu);
} else {
memcpy(guest_xsave->region,
x86/fpu: Simplify FPU handling by embedding the fpstate in task_struct (again) So 6 years ago we made the FPU fpstate dynamically allocated: aa283f49276e ("x86, fpu: lazy allocation of FPU area - v5") 61c4628b5386 ("x86, fpu: split FPU state from task struct - v5") In hindsight this was a mistake: - it complicated context allocation failure handling, such as: /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(fpstate_alloc_init(fpu))) force_sig(SIGKILL, tsk); - it caused us to enable irqs in fpu__restore(): local_irq_enable(); /* * does a slab alloc which can sleep */ if (fpstate_alloc_init(fpu)) { /* * ran out of memory! */ do_group_exit(SIGKILL); return; } local_irq_disable(); - it (slightly) slowed down task creation/destruction by adding slab allocation/free pattens. - it made access to context contents (slightly) slower by adding one more pointer dereference. The motivation for the dynamic allocation was two-fold: - reduce memory consumption by non-FPU tasks - allocate and handle only the necessary amount of context for various XSAVE processors that have varying hardware frame sizes. These days, with glibc using SSE memcpy by default and GCC optimizing for SSE/AVX by default, the scope of FPU using apps on an x86 system is much larger than it was 6 years ago. For example on a freshly installed Fedora 21 desktop system, with a recent kernel, all non-kthread tasks have used the FPU shortly after bootup. Also, even modern embedded x86 CPUs try to support the latest vector instruction set - so they'll too often use the larger xstate frame sizes. So remove the dynamic allocation complication by embedding the FPU fpstate in task_struct again. This should make the FPU a lot more accessible to all sorts of atomic contexts. We could still optimize for the xstate frame size in the future, by moving the state structure to the last element of task_struct, and allocating only a part of that. This change is kept minimal by still keeping the ctx_alloc()/free() routines (that now do nothing substantial) - we'll remove them in the following patches. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-27 02:19:39 +00:00
&vcpu->arch.guest_fpu.state.fxsave,
sizeof(struct fxregs_state));
*(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)] =
XSTATE_FPSSE;
}
}
static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
struct kvm_xsave *guest_xsave)
{
u64 xstate_bv =
*(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)];
if (cpu_has_xsave) {
/*
* Here we allow setting states that are not present in
* CPUID leaf 0xD, index 0, EDX:EAX. This is for compatibility
* with old userspace.
*/
if (xstate_bv & ~kvm_supported_xcr0())
return -EINVAL;
load_xsave(vcpu, (u8 *)guest_xsave->region);
} else {
if (xstate_bv & ~XSTATE_FPSSE)
return -EINVAL;
x86/fpu: Simplify FPU handling by embedding the fpstate in task_struct (again) So 6 years ago we made the FPU fpstate dynamically allocated: aa283f49276e ("x86, fpu: lazy allocation of FPU area - v5") 61c4628b5386 ("x86, fpu: split FPU state from task struct - v5") In hindsight this was a mistake: - it complicated context allocation failure handling, such as: /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(fpstate_alloc_init(fpu))) force_sig(SIGKILL, tsk); - it caused us to enable irqs in fpu__restore(): local_irq_enable(); /* * does a slab alloc which can sleep */ if (fpstate_alloc_init(fpu)) { /* * ran out of memory! */ do_group_exit(SIGKILL); return; } local_irq_disable(); - it (slightly) slowed down task creation/destruction by adding slab allocation/free pattens. - it made access to context contents (slightly) slower by adding one more pointer dereference. The motivation for the dynamic allocation was two-fold: - reduce memory consumption by non-FPU tasks - allocate and handle only the necessary amount of context for various XSAVE processors that have varying hardware frame sizes. These days, with glibc using SSE memcpy by default and GCC optimizing for SSE/AVX by default, the scope of FPU using apps on an x86 system is much larger than it was 6 years ago. For example on a freshly installed Fedora 21 desktop system, with a recent kernel, all non-kthread tasks have used the FPU shortly after bootup. Also, even modern embedded x86 CPUs try to support the latest vector instruction set - so they'll too often use the larger xstate frame sizes. So remove the dynamic allocation complication by embedding the FPU fpstate in task_struct again. This should make the FPU a lot more accessible to all sorts of atomic contexts. We could still optimize for the xstate frame size in the future, by moving the state structure to the last element of task_struct, and allocating only a part of that. This change is kept minimal by still keeping the ctx_alloc()/free() routines (that now do nothing substantial) - we'll remove them in the following patches. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-27 02:19:39 +00:00
memcpy(&vcpu->arch.guest_fpu.state.fxsave,
guest_xsave->region, sizeof(struct fxregs_state));
}
return 0;
}
static void kvm_vcpu_ioctl_x86_get_xcrs(struct kvm_vcpu *vcpu,
struct kvm_xcrs *guest_xcrs)
{
if (!cpu_has_xsave) {
guest_xcrs->nr_xcrs = 0;
return;
}
guest_xcrs->nr_xcrs = 1;
guest_xcrs->flags = 0;
guest_xcrs->xcrs[0].xcr = XCR_XFEATURE_ENABLED_MASK;
guest_xcrs->xcrs[0].value = vcpu->arch.xcr0;
}
static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu,
struct kvm_xcrs *guest_xcrs)
{
int i, r = 0;
if (!cpu_has_xsave)
return -EINVAL;
if (guest_xcrs->nr_xcrs > KVM_MAX_XCRS || guest_xcrs->flags)
return -EINVAL;
for (i = 0; i < guest_xcrs->nr_xcrs; i++)
/* Only support XCR0 currently */
if (guest_xcrs->xcrs[i].xcr == XCR_XFEATURE_ENABLED_MASK) {
r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
guest_xcrs->xcrs[i].value);
break;
}
if (r)
r = -EINVAL;
return r;
}
/*
* kvm_set_guest_paused() indicates to the guest kernel that it has been
* stopped by the hypervisor. This function will be called from the host only.
* EINVAL is returned when the host attempts to set the flag for a guest that
* does not support pv clocks.
*/
static int kvm_set_guest_paused(struct kvm_vcpu *vcpu)
{
if (!vcpu->arch.pv_time_enabled)
return -EINVAL;
vcpu->arch.pvclock_set_guest_stopped_request = true;
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
return 0;
}
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
int r;
union {
struct kvm_lapic_state *lapic;
struct kvm_xsave *xsave;
struct kvm_xcrs *xcrs;
void *buffer;
} u;
u.buffer = NULL;
switch (ioctl) {
case KVM_GET_LAPIC: {
r = -EINVAL;
if (!vcpu->arch.apic)
goto out;
u.lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
r = -ENOMEM;
if (!u.lapic)
goto out;
r = kvm_vcpu_ioctl_get_lapic(vcpu, u.lapic);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, u.lapic, sizeof(struct kvm_lapic_state)))
goto out;
r = 0;
break;
}
case KVM_SET_LAPIC: {
r = -EINVAL;
if (!vcpu->arch.apic)
goto out;
u.lapic = memdup_user(argp, sizeof(*u.lapic));
if (IS_ERR(u.lapic))
return PTR_ERR(u.lapic);
r = kvm_vcpu_ioctl_set_lapic(vcpu, u.lapic);
break;
}
case KVM_INTERRUPT: {
struct kvm_interrupt irq;
r = -EFAULT;
if (copy_from_user(&irq, argp, sizeof irq))
goto out;
r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
break;
}
case KVM_NMI: {
r = kvm_vcpu_ioctl_nmi(vcpu);
break;
}
case KVM_SMI: {
r = kvm_vcpu_ioctl_smi(vcpu);
break;
}
case KVM_SET_CPUID: {
struct kvm_cpuid __user *cpuid_arg = argp;
struct kvm_cpuid cpuid;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
goto out;
r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries);
break;
}
case KVM_SET_CPUID2: {
struct kvm_cpuid2 __user *cpuid_arg = argp;
struct kvm_cpuid2 cpuid;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
goto out;
r = kvm_vcpu_ioctl_set_cpuid2(vcpu, &cpuid,
cpuid_arg->entries);
break;
}
case KVM_GET_CPUID2: {
struct kvm_cpuid2 __user *cpuid_arg = argp;
struct kvm_cpuid2 cpuid;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
goto out;
r = kvm_vcpu_ioctl_get_cpuid2(vcpu, &cpuid,
cpuid_arg->entries);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
goto out;
r = 0;
break;
}
case KVM_GET_MSRS:
r = msr_io(vcpu, argp, do_get_msr, 1);
break;
case KVM_SET_MSRS:
r = msr_io(vcpu, argp, do_set_msr, 0);
break;
case KVM_TPR_ACCESS_REPORTING: {
struct kvm_tpr_access_ctl tac;
r = -EFAULT;
if (copy_from_user(&tac, argp, sizeof tac))
goto out;
r = vcpu_ioctl_tpr_access_reporting(vcpu, &tac);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &tac, sizeof tac))
goto out;
r = 0;
break;
};
case KVM_SET_VAPIC_ADDR: {
struct kvm_vapic_addr va;
r = -EINVAL;
if (!irqchip_in_kernel(vcpu->kvm))
goto out;
r = -EFAULT;
if (copy_from_user(&va, argp, sizeof va))
goto out;
r = kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
break;
}
case KVM_X86_SETUP_MCE: {
u64 mcg_cap;
r = -EFAULT;
if (copy_from_user(&mcg_cap, argp, sizeof mcg_cap))
goto out;
r = kvm_vcpu_ioctl_x86_setup_mce(vcpu, mcg_cap);
break;
}
case KVM_X86_SET_MCE: {
struct kvm_x86_mce mce;
r = -EFAULT;
if (copy_from_user(&mce, argp, sizeof mce))
goto out;
r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
break;
}
case KVM_GET_VCPU_EVENTS: {
struct kvm_vcpu_events events;
kvm_vcpu_ioctl_x86_get_vcpu_events(vcpu, &events);
r = -EFAULT;
if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events)))
break;
r = 0;
break;
}
case KVM_SET_VCPU_EVENTS: {
struct kvm_vcpu_events events;
r = -EFAULT;
if (copy_from_user(&events, argp, sizeof(struct kvm_vcpu_events)))
break;
r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events);
break;
}
case KVM_GET_DEBUGREGS: {
struct kvm_debugregs dbgregs;
kvm_vcpu_ioctl_x86_get_debugregs(vcpu, &dbgregs);
r = -EFAULT;
if (copy_to_user(argp, &dbgregs,
sizeof(struct kvm_debugregs)))
break;
r = 0;
break;
}
case KVM_SET_DEBUGREGS: {
struct kvm_debugregs dbgregs;
r = -EFAULT;
if (copy_from_user(&dbgregs, argp,
sizeof(struct kvm_debugregs)))
break;
r = kvm_vcpu_ioctl_x86_set_debugregs(vcpu, &dbgregs);
break;
}
case KVM_GET_XSAVE: {
u.xsave = kzalloc(sizeof(struct kvm_xsave), GFP_KERNEL);
r = -ENOMEM;
if (!u.xsave)
break;
kvm_vcpu_ioctl_x86_get_xsave(vcpu, u.xsave);
r = -EFAULT;
if (copy_to_user(argp, u.xsave, sizeof(struct kvm_xsave)))
break;
r = 0;
break;
}
case KVM_SET_XSAVE: {
u.xsave = memdup_user(argp, sizeof(*u.xsave));
if (IS_ERR(u.xsave))
return PTR_ERR(u.xsave);
r = kvm_vcpu_ioctl_x86_set_xsave(vcpu, u.xsave);
break;
}
case KVM_GET_XCRS: {
u.xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL);
r = -ENOMEM;
if (!u.xcrs)
break;
kvm_vcpu_ioctl_x86_get_xcrs(vcpu, u.xcrs);
r = -EFAULT;
if (copy_to_user(argp, u.xcrs,
sizeof(struct kvm_xcrs)))
break;
r = 0;
break;
}
case KVM_SET_XCRS: {
u.xcrs = memdup_user(argp, sizeof(*u.xcrs));
if (IS_ERR(u.xcrs))
return PTR_ERR(u.xcrs);
r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, u.xcrs);
break;
}
case KVM_SET_TSC_KHZ: {
u32 user_tsc_khz;
r = -EINVAL;
user_tsc_khz = (u32)arg;
if (user_tsc_khz >= kvm_max_guest_tsc_khz)
goto out;
2012-02-03 17:43:50 +00:00
if (user_tsc_khz == 0)
user_tsc_khz = tsc_khz;
kvm_set_tsc_khz(vcpu, user_tsc_khz);
r = 0;
goto out;
}
case KVM_GET_TSC_KHZ: {
2012-02-03 17:43:50 +00:00
r = vcpu->arch.virtual_tsc_khz;
goto out;
}
case KVM_KVMCLOCK_CTRL: {
r = kvm_set_guest_paused(vcpu);
goto out;
}
default:
r = -EINVAL;
}
out:
kfree(u.buffer);
return r;
}
int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
return VM_FAULT_SIGBUS;
}
static int kvm_vm_ioctl_set_tss_addr(struct kvm *kvm, unsigned long addr)
{
int ret;
if (addr > (unsigned int)(-3 * PAGE_SIZE))
return -EINVAL;
ret = kvm_x86_ops->set_tss_addr(kvm, addr);
return ret;
}
static int kvm_vm_ioctl_set_identity_map_addr(struct kvm *kvm,
u64 ident_addr)
{
kvm->arch.ept_identity_map_addr = ident_addr;
return 0;
}
static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
u32 kvm_nr_mmu_pages)
{
if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
return -EINVAL;
mutex_lock(&kvm->slots_lock);
kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;
mutex_unlock(&kvm->slots_lock);
return 0;
}
static int kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm)
{
return kvm->arch.n_max_mmu_pages;
}
static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
int r;
r = 0;
switch (chip->chip_id) {
case KVM_IRQCHIP_PIC_MASTER:
memcpy(&chip->chip.pic,
&pic_irqchip(kvm)->pics[0],
sizeof(struct kvm_pic_state));
break;
case KVM_IRQCHIP_PIC_SLAVE:
memcpy(&chip->chip.pic,
&pic_irqchip(kvm)->pics[1],
sizeof(struct kvm_pic_state));
break;
case KVM_IRQCHIP_IOAPIC:
r = kvm_get_ioapic(kvm, &chip->chip.ioapic);
break;
default:
r = -EINVAL;
break;
}
return r;
}
static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
int r;
r = 0;
switch (chip->chip_id) {
case KVM_IRQCHIP_PIC_MASTER:
spin_lock(&pic_irqchip(kvm)->lock);
memcpy(&pic_irqchip(kvm)->pics[0],
&chip->chip.pic,
sizeof(struct kvm_pic_state));
spin_unlock(&pic_irqchip(kvm)->lock);
break;
case KVM_IRQCHIP_PIC_SLAVE:
spin_lock(&pic_irqchip(kvm)->lock);
memcpy(&pic_irqchip(kvm)->pics[1],
&chip->chip.pic,
sizeof(struct kvm_pic_state));
spin_unlock(&pic_irqchip(kvm)->lock);
break;
case KVM_IRQCHIP_IOAPIC:
r = kvm_set_ioapic(kvm, &chip->chip.ioapic);
break;
default:
r = -EINVAL;
break;
}
kvm_pic_update_irq(pic_irqchip(kvm));
return r;
}
static int kvm_vm_ioctl_get_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
int r = 0;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
memcpy(ps, &kvm->arch.vpit->pit_state, sizeof(struct kvm_pit_state));
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
return r;
}
static int kvm_vm_ioctl_set_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
int r = 0;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
memcpy(&kvm->arch.vpit->pit_state, ps, sizeof(struct kvm_pit_state));
kvm_pit_load_count(kvm, 0, ps->channels[0].count, 0);
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
return r;
}
static int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
int r = 0;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
memcpy(ps->channels, &kvm->arch.vpit->pit_state.channels,
sizeof(ps->channels));
ps->flags = kvm->arch.vpit->pit_state.flags;
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
memset(&ps->reserved, 0, sizeof(ps->reserved));
return r;
}
static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
int r = 0, start = 0;
u32 prev_legacy, cur_legacy;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
prev_legacy = kvm->arch.vpit->pit_state.flags & KVM_PIT_FLAGS_HPET_LEGACY;
cur_legacy = ps->flags & KVM_PIT_FLAGS_HPET_LEGACY;
if (!prev_legacy && cur_legacy)
start = 1;
memcpy(&kvm->arch.vpit->pit_state.channels, &ps->channels,
sizeof(kvm->arch.vpit->pit_state.channels));
kvm->arch.vpit->pit_state.flags = ps->flags;
kvm_pit_load_count(kvm, 0, kvm->arch.vpit->pit_state.channels[0].count, start);
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
return r;
}
static int kvm_vm_ioctl_reinject(struct kvm *kvm,
struct kvm_reinject_control *control)
{
if (!kvm->arch.vpit)
return -ENXIO;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
kvm->arch.vpit->pit_state.reinject = control->pit_reinject;
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
return 0;
}
/**
KVM: Switch to srcu-less get_dirty_log() We have seen some problems of the current implementation of get_dirty_log() which uses synchronize_srcu_expedited() for updating dirty bitmaps; e.g. it is noticeable that this sometimes gives us ms order of latency when we use VGA displays. Furthermore the recent discussion on the following thread "srcu: Implement call_srcu()" http://lkml.org/lkml/2012/1/31/211 also motivated us to implement get_dirty_log() without SRCU. This patch achieves this goal without sacrificing the performance of both VGA and live migration: in practice the new code is much faster than the old one unless we have too many dirty pages. Implementation: The key part of the implementation is the use of xchg() operation for clearing dirty bits atomically. Since this allows us to update only BITS_PER_LONG pages at once, we need to iterate over the dirty bitmap until every dirty bit is cleared again for the next call. Although some people may worry about the problem of using the atomic memory instruction many times to the concurrently accessible bitmap, it is usually accessed with mmu_lock held and we rarely see concurrent accesses: so what we need to care about is the pure xchg() overheads. Another point to note is that we do not use for_each_set_bit() to check which ones in each BITS_PER_LONG pages are actually dirty. Instead we simply use __ffs() in a loop. This is much faster than repeatedly call find_next_bit(). Performance: The dirty-log-perf unit test showed nice improvements, some times faster than before, except for some extreme cases; for such cases the speed of getting dirty page information is much faster than we process it in the userspace. For real workloads, both VGA and live migration, we have observed pure improvements: when the guest was reading a file during live migration, we originally saw a few ms of latency, but with the new method the latency was less than 200us. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-03 05:21:48 +00:00
* kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
* @kvm: kvm instance
* @log: slot id and address to which we copy the log
*
* Steps 1-4 below provide general overview of dirty page logging. See
* kvm_get_dirty_log_protect() function description for additional details.
*
* We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
* always flush the TLB (step 4) even if previous step failed and the dirty
* bitmap may be corrupt. Regardless of previous outcome the KVM logging API
* does not preclude user space subsequent dirty log read. Flushing TLB ensures
* writes will be marked dirty for next log read.
*
KVM: Switch to srcu-less get_dirty_log() We have seen some problems of the current implementation of get_dirty_log() which uses synchronize_srcu_expedited() for updating dirty bitmaps; e.g. it is noticeable that this sometimes gives us ms order of latency when we use VGA displays. Furthermore the recent discussion on the following thread "srcu: Implement call_srcu()" http://lkml.org/lkml/2012/1/31/211 also motivated us to implement get_dirty_log() without SRCU. This patch achieves this goal without sacrificing the performance of both VGA and live migration: in practice the new code is much faster than the old one unless we have too many dirty pages. Implementation: The key part of the implementation is the use of xchg() operation for clearing dirty bits atomically. Since this allows us to update only BITS_PER_LONG pages at once, we need to iterate over the dirty bitmap until every dirty bit is cleared again for the next call. Although some people may worry about the problem of using the atomic memory instruction many times to the concurrently accessible bitmap, it is usually accessed with mmu_lock held and we rarely see concurrent accesses: so what we need to care about is the pure xchg() overheads. Another point to note is that we do not use for_each_set_bit() to check which ones in each BITS_PER_LONG pages are actually dirty. Instead we simply use __ffs() in a loop. This is much faster than repeatedly call find_next_bit(). Performance: The dirty-log-perf unit test showed nice improvements, some times faster than before, except for some extreme cases; for such cases the speed of getting dirty page information is much faster than we process it in the userspace. For real workloads, both VGA and live migration, we have observed pure improvements: when the guest was reading a file during live migration, we originally saw a few ms of latency, but with the new method the latency was less than 200us. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-03 05:21:48 +00:00
* 1. Take a snapshot of the bit and clear it if needed.
* 2. Write protect the corresponding page.
* 3. Copy the snapshot to the userspace.
* 4. Flush TLB's if needed.
*/
KVM: Switch to srcu-less get_dirty_log() We have seen some problems of the current implementation of get_dirty_log() which uses synchronize_srcu_expedited() for updating dirty bitmaps; e.g. it is noticeable that this sometimes gives us ms order of latency when we use VGA displays. Furthermore the recent discussion on the following thread "srcu: Implement call_srcu()" http://lkml.org/lkml/2012/1/31/211 also motivated us to implement get_dirty_log() without SRCU. This patch achieves this goal without sacrificing the performance of both VGA and live migration: in practice the new code is much faster than the old one unless we have too many dirty pages. Implementation: The key part of the implementation is the use of xchg() operation for clearing dirty bits atomically. Since this allows us to update only BITS_PER_LONG pages at once, we need to iterate over the dirty bitmap until every dirty bit is cleared again for the next call. Although some people may worry about the problem of using the atomic memory instruction many times to the concurrently accessible bitmap, it is usually accessed with mmu_lock held and we rarely see concurrent accesses: so what we need to care about is the pure xchg() overheads. Another point to note is that we do not use for_each_set_bit() to check which ones in each BITS_PER_LONG pages are actually dirty. Instead we simply use __ffs() in a loop. This is much faster than repeatedly call find_next_bit(). Performance: The dirty-log-perf unit test showed nice improvements, some times faster than before, except for some extreme cases; for such cases the speed of getting dirty page information is much faster than we process it in the userspace. For real workloads, both VGA and live migration, we have observed pure improvements: when the guest was reading a file during live migration, we originally saw a few ms of latency, but with the new method the latency was less than 200us. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-03 05:21:48 +00:00
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
{
KVM: Switch to srcu-less get_dirty_log() We have seen some problems of the current implementation of get_dirty_log() which uses synchronize_srcu_expedited() for updating dirty bitmaps; e.g. it is noticeable that this sometimes gives us ms order of latency when we use VGA displays. Furthermore the recent discussion on the following thread "srcu: Implement call_srcu()" http://lkml.org/lkml/2012/1/31/211 also motivated us to implement get_dirty_log() without SRCU. This patch achieves this goal without sacrificing the performance of both VGA and live migration: in practice the new code is much faster than the old one unless we have too many dirty pages. Implementation: The key part of the implementation is the use of xchg() operation for clearing dirty bits atomically. Since this allows us to update only BITS_PER_LONG pages at once, we need to iterate over the dirty bitmap until every dirty bit is cleared again for the next call. Although some people may worry about the problem of using the atomic memory instruction many times to the concurrently accessible bitmap, it is usually accessed with mmu_lock held and we rarely see concurrent accesses: so what we need to care about is the pure xchg() overheads. Another point to note is that we do not use for_each_set_bit() to check which ones in each BITS_PER_LONG pages are actually dirty. Instead we simply use __ffs() in a loop. This is much faster than repeatedly call find_next_bit(). Performance: The dirty-log-perf unit test showed nice improvements, some times faster than before, except for some extreme cases; for such cases the speed of getting dirty page information is much faster than we process it in the userspace. For real workloads, both VGA and live migration, we have observed pure improvements: when the guest was reading a file during live migration, we originally saw a few ms of latency, but with the new method the latency was less than 200us. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-03 05:21:48 +00:00
bool is_dirty = false;
int r;
mutex_lock(&kvm->slots_lock);
/*
* Flush potentially hardware-cached dirty pages to dirty_bitmap.
*/
if (kvm_x86_ops->flush_log_dirty)
kvm_x86_ops->flush_log_dirty(kvm);
r = kvm_get_dirty_log_protect(kvm, log, &is_dirty);
/*
* All the TLBs can be flushed out of mmu lock, see the comments in
* kvm_mmu_slot_remove_write_access().
*/
lockdep_assert_held(&kvm->slots_lock);
if (is_dirty)
kvm_flush_remote_tlbs(kvm);
mutex_unlock(&kvm->slots_lock);
return r;
}
int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_event,
bool line_status)
{
if (!irqchip_in_kernel(kvm))
return -ENXIO;
irq_event->status = kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
irq_event->irq, irq_event->level,
line_status);
return 0;
}
static int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
struct kvm_enable_cap *cap)
{
int r;
if (cap->flags)
return -EINVAL;
switch (cap->cap) {
case KVM_CAP_DISABLE_QUIRKS:
kvm->arch.disabled_quirks = cap->args[0];
r = 0;
break;
default:
r = -EINVAL;
break;
}
return r;
}
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm *kvm = filp->private_data;
void __user *argp = (void __user *)arg;
int r = -ENOTTY;
/*
* This union makes it completely explicit to gcc-3.x
* that these two variables' stack usage should be
* combined, not added together.
*/
union {
struct kvm_pit_state ps;
struct kvm_pit_state2 ps2;
struct kvm_pit_config pit_config;
} u;
switch (ioctl) {
case KVM_SET_TSS_ADDR:
r = kvm_vm_ioctl_set_tss_addr(kvm, arg);
break;
case KVM_SET_IDENTITY_MAP_ADDR: {
u64 ident_addr;
r = -EFAULT;
if (copy_from_user(&ident_addr, argp, sizeof ident_addr))
goto out;
r = kvm_vm_ioctl_set_identity_map_addr(kvm, ident_addr);
break;
}
case KVM_SET_NR_MMU_PAGES:
r = kvm_vm_ioctl_set_nr_mmu_pages(kvm, arg);
break;
case KVM_GET_NR_MMU_PAGES:
r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
break;
case KVM_CREATE_IRQCHIP: {
struct kvm_pic *vpic;
mutex_lock(&kvm->lock);
r = -EEXIST;
if (kvm->arch.vpic)
goto create_irqchip_unlock;
r = -EINVAL;
if (atomic_read(&kvm->online_vcpus))
goto create_irqchip_unlock;
r = -ENOMEM;
vpic = kvm_create_pic(kvm);
if (vpic) {
r = kvm_ioapic_init(kvm);
if (r) {
mutex_lock(&kvm->slots_lock);
kvm_destroy_pic(vpic);
mutex_unlock(&kvm->slots_lock);
goto create_irqchip_unlock;
}
} else
goto create_irqchip_unlock;
r = kvm_setup_default_irq_routing(kvm);
if (r) {
mutex_lock(&kvm->slots_lock);
mutex_lock(&kvm->irq_lock);
kvm_ioapic_destroy(kvm);
kvm_destroy_pic(vpic);
mutex_unlock(&kvm->irq_lock);
mutex_unlock(&kvm->slots_lock);
goto create_irqchip_unlock;
}
/* Write kvm->irq_routing before kvm->arch.vpic. */
smp_wmb();
kvm->arch.vpic = vpic;
create_irqchip_unlock:
mutex_unlock(&kvm->lock);
break;
}
case KVM_CREATE_PIT:
u.pit_config.flags = KVM_PIT_SPEAKER_DUMMY;
goto create_pit;
case KVM_CREATE_PIT2:
r = -EFAULT;
if (copy_from_user(&u.pit_config, argp,
sizeof(struct kvm_pit_config)))
goto out;
create_pit:
mutex_lock(&kvm->slots_lock);
r = -EEXIST;
if (kvm->arch.vpit)
goto create_pit_unlock;
r = -ENOMEM;
kvm->arch.vpit = kvm_create_pit(kvm, u.pit_config.flags);
if (kvm->arch.vpit)
r = 0;
create_pit_unlock:
mutex_unlock(&kvm->slots_lock);
break;
case KVM_GET_IRQCHIP: {
/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
struct kvm_irqchip *chip;
chip = memdup_user(argp, sizeof(*chip));
if (IS_ERR(chip)) {
r = PTR_ERR(chip);
goto out;
}
r = -ENXIO;
if (!irqchip_in_kernel(kvm))
goto get_irqchip_out;
r = kvm_vm_ioctl_get_irqchip(kvm, chip);
if (r)
goto get_irqchip_out;
r = -EFAULT;
if (copy_to_user(argp, chip, sizeof *chip))
goto get_irqchip_out;
r = 0;
get_irqchip_out:
kfree(chip);
break;
}
case KVM_SET_IRQCHIP: {
/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
struct kvm_irqchip *chip;
chip = memdup_user(argp, sizeof(*chip));
if (IS_ERR(chip)) {
r = PTR_ERR(chip);
goto out;
}
r = -ENXIO;
if (!irqchip_in_kernel(kvm))
goto set_irqchip_out;
r = kvm_vm_ioctl_set_irqchip(kvm, chip);
if (r)
goto set_irqchip_out;
r = 0;
set_irqchip_out:
kfree(chip);
break;
}
case KVM_GET_PIT: {
r = -EFAULT;
if (copy_from_user(&u.ps, argp, sizeof(struct kvm_pit_state)))
goto out;
r = -ENXIO;
if (!kvm->arch.vpit)
goto out;
r = kvm_vm_ioctl_get_pit(kvm, &u.ps);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &u.ps, sizeof(struct kvm_pit_state)))
goto out;
r = 0;
break;
}
case KVM_SET_PIT: {
r = -EFAULT;
if (copy_from_user(&u.ps, argp, sizeof u.ps))
goto out;
r = -ENXIO;
if (!kvm->arch.vpit)
goto out;
r = kvm_vm_ioctl_set_pit(kvm, &u.ps);
break;
}
case KVM_GET_PIT2: {
r = -ENXIO;
if (!kvm->arch.vpit)
goto out;
r = kvm_vm_ioctl_get_pit2(kvm, &u.ps2);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &u.ps2, sizeof(u.ps2)))
goto out;
r = 0;
break;
}
case KVM_SET_PIT2: {
r = -EFAULT;
if (copy_from_user(&u.ps2, argp, sizeof(u.ps2)))
goto out;
r = -ENXIO;
if (!kvm->arch.vpit)
goto out;
r = kvm_vm_ioctl_set_pit2(kvm, &u.ps2);
break;
}
case KVM_REINJECT_CONTROL: {
struct kvm_reinject_control control;
r = -EFAULT;
if (copy_from_user(&control, argp, sizeof(control)))
goto out;
r = kvm_vm_ioctl_reinject(kvm, &control);
break;
}
case KVM_SET_BOOT_CPU_ID:
r = 0;
mutex_lock(&kvm->lock);
if (atomic_read(&kvm->online_vcpus) != 0)
r = -EBUSY;
else
kvm->arch.bsp_vcpu_id = arg;
mutex_unlock(&kvm->lock);
break;
case KVM_XEN_HVM_CONFIG: {
r = -EFAULT;
if (copy_from_user(&kvm->arch.xen_hvm_config, argp,
sizeof(struct kvm_xen_hvm_config)))
goto out;
r = -EINVAL;
if (kvm->arch.xen_hvm_config.flags)
goto out;
r = 0;
break;
}
case KVM_SET_CLOCK: {
struct kvm_clock_data user_ns;
u64 now_ns;
s64 delta;
r = -EFAULT;
if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
goto out;
r = -EINVAL;
if (user_ns.flags)
goto out;
r = 0;
local_irq_disable();
now_ns = get_kernel_ns();
delta = user_ns.clock - now_ns;
local_irq_enable();
kvm->arch.kvmclock_offset = delta;
kvm_gen_update_masterclock(kvm);
break;
}
case KVM_GET_CLOCK: {
struct kvm_clock_data user_ns;
u64 now_ns;
local_irq_disable();
now_ns = get_kernel_ns();
user_ns.clock = kvm->arch.kvmclock_offset + now_ns;
local_irq_enable();
user_ns.flags = 0;
memset(&user_ns.pad, 0, sizeof(user_ns.pad));
r = -EFAULT;
if (copy_to_user(argp, &user_ns, sizeof(user_ns)))
goto out;
r = 0;
break;
}
case KVM_ENABLE_CAP: {
struct kvm_enable_cap cap;
r = -EFAULT;
if (copy_from_user(&cap, argp, sizeof(cap)))
goto out;
r = kvm_vm_ioctl_enable_cap(kvm, &cap);
break;
}
default:
r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
}
out:
return r;
}
static void kvm_init_msr_list(void)
{
u32 dummy[2];
unsigned i, j;
for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
continue;
/*
* Even MSRs that are valid in the host may not be exposed
* to the guests in some cases. We could work around this
* in VMX with the generic MSR save/load machinery, but it
* is not really worthwhile since it will really only
* happen with nested virtualization.
*/
switch (msrs_to_save[i]) {
case MSR_IA32_BNDCFGS:
if (!kvm_x86_ops->mpx_supported())
continue;
break;
default:
break;
}
if (j < i)
msrs_to_save[j] = msrs_to_save[i];
j++;
}
num_msrs_to_save = j;
for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) {
switch (emulated_msrs[i]) {
case MSR_IA32_SMBASE:
if (!kvm_x86_ops->cpu_has_high_real_mode_segbase())
continue;
break;
default:
break;
}
if (j < i)
emulated_msrs[j] = emulated_msrs[i];
j++;
}
num_emulated_msrs = j;
}
static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
const void *v)
{
int handled = 0;
int n;
do {
n = min(len, 8);
if (!(vcpu->arch.apic &&
!kvm_iodevice_write(vcpu, &vcpu->arch.apic->dev, addr, n, v))
&& kvm_io_bus_write(vcpu, KVM_MMIO_BUS, addr, n, v))
break;
handled += n;
addr += n;
len -= n;
v += n;
} while (len);
return handled;
}
static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
{
int handled = 0;
int n;
do {
n = min(len, 8);
if (!(vcpu->arch.apic &&
!kvm_iodevice_read(vcpu, &vcpu->arch.apic->dev,
addr, n, v))
&& kvm_io_bus_read(vcpu, KVM_MMIO_BUS, addr, n, v))
break;
trace_kvm_mmio(KVM_TRACE_MMIO_READ, n, addr, *(u64 *)v);
handled += n;
addr += n;
len -= n;
v += n;
} while (len);
return handled;
}
static void kvm_set_segment(struct kvm_vcpu *vcpu,
struct kvm_segment *var, int seg)
{
kvm_x86_ops->set_segment(vcpu, var, seg);
}
void kvm_get_segment(struct kvm_vcpu *vcpu,
struct kvm_segment *var, int seg)
{
kvm_x86_ops->get_segment(vcpu, var, seg);
}
gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
struct x86_exception *exception)
{
gpa_t t_gpa;
BUG_ON(!mmu_is_nested(vcpu));
/* NPT walks are always user-walks */
access |= PFERR_USER_MASK;
t_gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gpa, access, exception);
return t_gpa;
}
gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
struct x86_exception *exception)
{
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
}
gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
struct x86_exception *exception)
{
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
access |= PFERR_FETCH_MASK;
return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
}
gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
struct x86_exception *exception)
{
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
access |= PFERR_WRITE_MASK;
return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
}
/* uses this to access any guest's mapped memory without checking CPL */
gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
struct x86_exception *exception)
{
return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, 0, exception);
}
static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
struct kvm_vcpu *vcpu, u32 access,
struct x86_exception *exception)
{
void *data = val;
int r = X86EMUL_CONTINUE;
while (bytes) {
gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access,
exception);
unsigned offset = addr & (PAGE_SIZE-1);
unsigned toread = min(bytes, (unsigned)PAGE_SIZE - offset);
int ret;
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, data,
offset, toread);
if (ret < 0) {
r = X86EMUL_IO_NEEDED;
goto out;
}
bytes -= toread;
data += toread;
addr += toread;
}
out:
return r;
}
/* used for instruction fetching */
static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
gva_t addr, void *val, unsigned int bytes,
struct x86_exception *exception)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
unsigned offset;
int ret;
/* Inline kvm_read_guest_virt_helper for speed. */
gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access|PFERR_FETCH_MASK,
exception);
if (unlikely(gpa == UNMAPPED_GVA))
return X86EMUL_PROPAGATE_FAULT;
offset = addr & (PAGE_SIZE-1);
if (WARN_ON(offset + bytes > PAGE_SIZE))
bytes = (unsigned)PAGE_SIZE - offset;
ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, val,
offset, bytes);
if (unlikely(ret < 0))
return X86EMUL_IO_NEEDED;
return X86EMUL_CONTINUE;
}
int kvm_read_guest_virt(struct x86_emulate_ctxt *ctxt,
gva_t addr, void *val, unsigned int bytes,
struct x86_exception *exception)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access,
exception);
}
EXPORT_SYMBOL_GPL(kvm_read_guest_virt);
static int kvm_read_guest_virt_system(struct x86_emulate_ctxt *ctxt,
gva_t addr, void *val, unsigned int bytes,
struct x86_exception *exception)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, 0, exception);
}
int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt,
gva_t addr, void *val,
unsigned int bytes,
struct x86_exception *exception)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
void *data = val;
int r = X86EMUL_CONTINUE;
while (bytes) {
gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr,
PFERR_WRITE_MASK,
exception);
unsigned offset = addr & (PAGE_SIZE-1);
unsigned towrite = min(bytes, (unsigned)PAGE_SIZE - offset);
int ret;
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
ret = kvm_vcpu_write_guest(vcpu, gpa, data, towrite);
if (ret < 0) {
r = X86EMUL_IO_NEEDED;
goto out;
}
bytes -= towrite;
data += towrite;
addr += towrite;
}
out:
return r;
}
EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
gpa_t *gpa, struct x86_exception *exception,
bool write)
{
u32 access = ((kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0)
| (write ? PFERR_WRITE_MASK : 0);
if (vcpu_match_mmio_gva(vcpu, gva)
&& !permission_fault(vcpu, vcpu->arch.walk_mmu,
vcpu->arch.access, access)) {
*gpa = vcpu->arch.mmio_gfn << PAGE_SHIFT |
(gva & (PAGE_SIZE - 1));
trace_vcpu_match_mmio(gva, *gpa, write, false);
return 1;
}
*gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
if (*gpa == UNMAPPED_GVA)
return -1;
/* For APIC access vmexit */
if ((*gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
return 1;
if (vcpu_match_mmio_gpa(vcpu, *gpa)) {
trace_vcpu_match_mmio(gva, *gpa, write, true);
return 1;
}
return 0;
}
int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
const void *val, int bytes)
{
int ret;
ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
if (ret < 0)
return 0;
kvm_mmu_pte_write(vcpu, gpa, val, bytes);
return 1;
}
struct read_write_emulator_ops {
int (*read_write_prepare)(struct kvm_vcpu *vcpu, void *val,
int bytes);
int (*read_write_emulate)(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes);
int (*read_write_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
int bytes, void *val);
int (*read_write_exit_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes);
bool write;
};
static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
{
if (vcpu->mmio_read_completed) {
trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
vcpu->mmio_fragments[0].gpa, *(u64 *)val);
vcpu->mmio_read_completed = 0;
return 1;
}
return 0;
}
static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes)
{
return !kvm_vcpu_read_guest(vcpu, gpa, val, bytes);
}
static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes)
{
return emulator_write_phys(vcpu, gpa, val, bytes);
}
static int write_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes, void *val)
{
trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, *(u64 *)val);
return vcpu_mmio_write(vcpu, gpa, bytes, val);
}
static int read_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes)
{
trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, bytes, gpa, 0);
return X86EMUL_IO_NEEDED;
}
static int write_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes)
{
struct kvm_mmio_fragment *frag = &vcpu->mmio_fragments[0];
memcpy(vcpu->run->mmio.data, frag->data, min(8u, frag->len));
return X86EMUL_CONTINUE;
}
static const struct read_write_emulator_ops read_emultor = {
.read_write_prepare = read_prepare,
.read_write_emulate = read_emulate,
.read_write_mmio = vcpu_mmio_read,
.read_write_exit_mmio = read_exit_mmio,
};
static const struct read_write_emulator_ops write_emultor = {
.read_write_emulate = write_emulate,
.read_write_mmio = write_mmio,
.read_write_exit_mmio = write_exit_mmio,
.write = true,
};
static int emulator_read_write_onepage(unsigned long addr, void *val,
unsigned int bytes,
struct x86_exception *exception,
struct kvm_vcpu *vcpu,
const struct read_write_emulator_ops *ops)
{
gpa_t gpa;
int handled, ret;
bool write = ops->write;
struct kvm_mmio_fragment *frag;
ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
if (ret < 0)
return X86EMUL_PROPAGATE_FAULT;
/* For APIC access vmexit */
if (ret)
goto mmio;
if (ops->read_write_emulate(vcpu, gpa, val, bytes))
return X86EMUL_CONTINUE;
mmio:
/*
* Is this MMIO handled locally?
*/
handled = ops->read_write_mmio(vcpu, gpa, bytes, val);
if (handled == bytes)
return X86EMUL_CONTINUE;
gpa += handled;
bytes -= handled;
val += handled;
WARN_ON(vcpu->mmio_nr_fragments >= KVM_MAX_MMIO_FRAGMENTS);
frag = &vcpu->mmio_fragments[vcpu->mmio_nr_fragments++];
frag->gpa = gpa;
frag->data = val;
frag->len = bytes;
return X86EMUL_CONTINUE;
}
static int emulator_read_write(struct x86_emulate_ctxt *ctxt,
unsigned long addr,
void *val, unsigned int bytes,
struct x86_exception *exception,
const struct read_write_emulator_ops *ops)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
gpa_t gpa;
int rc;
if (ops->read_write_prepare &&
ops->read_write_prepare(vcpu, val, bytes))
return X86EMUL_CONTINUE;
vcpu->mmio_nr_fragments = 0;
/* Crossing a page boundary? */
if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
int now;
now = -addr & ~PAGE_MASK;
rc = emulator_read_write_onepage(addr, val, now, exception,
vcpu, ops);
if (rc != X86EMUL_CONTINUE)
return rc;
addr += now;
if (ctxt->mode != X86EMUL_MODE_PROT64)
addr = (u32)addr;
val += now;
bytes -= now;
}
rc = emulator_read_write_onepage(addr, val, bytes, exception,
vcpu, ops);
if (rc != X86EMUL_CONTINUE)
return rc;
if (!vcpu->mmio_nr_fragments)
return rc;
gpa = vcpu->mmio_fragments[0].gpa;
vcpu->mmio_needed = 1;
vcpu->mmio_cur_fragment = 0;
vcpu->run->mmio.len = min(8u, vcpu->mmio_fragments[0].len);
vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write;
vcpu->run->exit_reason = KVM_EXIT_MMIO;
vcpu->run->mmio.phys_addr = gpa;
return ops->read_write_exit_mmio(vcpu, gpa, val, bytes);
}
static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt,
unsigned long addr,
void *val,
unsigned int bytes,
struct x86_exception *exception)
{
return emulator_read_write(ctxt, addr, val, bytes,
exception, &read_emultor);
}
static int emulator_write_emulated(struct x86_emulate_ctxt *ctxt,
unsigned long addr,
const void *val,
unsigned int bytes,
struct x86_exception *exception)
{
return emulator_read_write(ctxt, addr, (void *)val, bytes,
exception, &write_emultor);
}
#define CMPXCHG_TYPE(t, ptr, old, new) \
(cmpxchg((t *)(ptr), *(t *)(old), *(t *)(new)) == *(t *)(old))
#ifdef CONFIG_X86_64
# define CMPXCHG64(ptr, old, new) CMPXCHG_TYPE(u64, ptr, old, new)
#else
# define CMPXCHG64(ptr, old, new) \
(cmpxchg64((u64 *)(ptr), *(u64 *)(old), *(u64 *)(new)) == *(u64 *)(old))
#endif
static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
unsigned long addr,
const void *old,
const void *new,
unsigned int bytes,
struct x86_exception *exception)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
gpa_t gpa;
struct page *page;
char *kaddr;
bool exchanged;
/* guests cmpxchg8b have to be emulated atomically */
if (bytes > 8 || (bytes & (bytes - 1)))
goto emul_write;
gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, NULL);
if (gpa == UNMAPPED_GVA ||
(gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
goto emul_write;
if (((gpa + bytes - 1) & PAGE_MASK) != (gpa & PAGE_MASK))
goto emul_write;
page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
if (is_error_page(page))
goto emul_write;
kaddr = kmap_atomic(page);
kaddr += offset_in_page(gpa);
switch (bytes) {
case 1:
exchanged = CMPXCHG_TYPE(u8, kaddr, old, new);
break;
case 2:
exchanged = CMPXCHG_TYPE(u16, kaddr, old, new);
break;
case 4:
exchanged = CMPXCHG_TYPE(u32, kaddr, old, new);
break;
case 8:
exchanged = CMPXCHG64(kaddr, old, new);
break;
default:
BUG();
}
kunmap_atomic(kaddr);
kvm_release_page_dirty(page);
if (!exchanged)
return X86EMUL_CMPXCHG_FAILED;
kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
kvm_mmu_pte_write(vcpu, gpa, new, bytes);
return X86EMUL_CONTINUE;
emul_write:
printk_once(KERN_WARNING "kvm: emulating exchange as write\n");
return emulator_write_emulated(ctxt, addr, new, bytes, exception);
}
static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
{
/* TODO: String I/O for in kernel device */
int r;
if (vcpu->arch.pio.in)
r = kvm_io_bus_read(vcpu, KVM_PIO_BUS, vcpu->arch.pio.port,
vcpu->arch.pio.size, pd);
else
r = kvm_io_bus_write(vcpu, KVM_PIO_BUS,
vcpu->arch.pio.port, vcpu->arch.pio.size,
pd);
return r;
}
static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
unsigned short port, void *val,
unsigned int count, bool in)
{
vcpu->arch.pio.port = port;
vcpu->arch.pio.in = in;
vcpu->arch.pio.count = count;
vcpu->arch.pio.size = size;
if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
vcpu->arch.pio.count = 0;
return 1;
}
vcpu->run->exit_reason = KVM_EXIT_IO;
vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
vcpu->run->io.size = size;
vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
vcpu->run->io.count = count;
vcpu->run->io.port = port;
return 0;
}
static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt,
int size, unsigned short port, void *val,
unsigned int count)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
int ret;
if (vcpu->arch.pio.count)
goto data_avail;
ret = emulator_pio_in_out(vcpu, size, port, val, count, true);
if (ret) {
data_avail:
memcpy(val, vcpu->arch.pio_data, size * count);
trace_kvm_pio(KVM_PIO_IN, port, size, count, vcpu->arch.pio_data);
vcpu->arch.pio.count = 0;
return 1;
}
return 0;
}
static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,
int size, unsigned short port,
const void *val, unsigned int count)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
memcpy(vcpu->arch.pio_data, val, size * count);
trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
return emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
}
static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
return kvm_x86_ops->get_segment_base(vcpu, seg);
}
static void emulator_invlpg(struct x86_emulate_ctxt *ctxt, ulong address)
{
kvm_mmu_invlpg(emul_to_vcpu(ctxt), address);
}
int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu)
{
if (!need_emulate_wbinvd(vcpu))
return X86EMUL_CONTINUE;
if (kvm_x86_ops->has_wbinvd_exit()) {
int cpu = get_cpu();
cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
wbinvd_ipi, NULL, 1);
put_cpu();
cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
} else
wbinvd();
return X86EMUL_CONTINUE;
}
int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->skip_emulated_instruction(vcpu);
return kvm_emulate_wbinvd_noskip(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd);
static void emulator_wbinvd(struct x86_emulate_ctxt *ctxt)
{
kvm_emulate_wbinvd_noskip(emul_to_vcpu(ctxt));
}
static int emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr,
unsigned long *dest)
{
return kvm_get_dr(emul_to_vcpu(ctxt), dr, dest);
}
static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr,
unsigned long value)
{
return __kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
}
static u64 mk_cr_64(u64 curr_cr, u32 new_val)
{
return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
}
static unsigned long emulator_get_cr(struct x86_emulate_ctxt *ctxt, int cr)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
unsigned long value;
switch (cr) {
case 0:
value = kvm_read_cr0(vcpu);
break;
case 2:
value = vcpu->arch.cr2;
break;
case 3:
value = kvm_read_cr3(vcpu);
break;
case 4:
value = kvm_read_cr4(vcpu);
break;
case 8:
value = kvm_get_cr8(vcpu);
break;
default:
kvm_err("%s: unexpected cr %u\n", __func__, cr);
return 0;
}
return value;
}
static int emulator_set_cr(struct x86_emulate_ctxt *ctxt, int cr, ulong val)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
int res = 0;
switch (cr) {
case 0:
res = kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val));
break;
case 2:
vcpu->arch.cr2 = val;
break;
case 3:
res = kvm_set_cr3(vcpu, val);
break;
case 4:
res = kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val));
break;
case 8:
res = kvm_set_cr8(vcpu, val);
break;
default:
kvm_err("%s: unexpected cr %u\n", __func__, cr);
res = -1;
}
return res;
}
static int emulator_get_cpl(struct x86_emulate_ctxt *ctxt)
{
return kvm_x86_ops->get_cpl(emul_to_vcpu(ctxt));
}
static void emulator_get_gdt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
kvm_x86_ops->get_gdt(emul_to_vcpu(ctxt), dt);
}
static void emulator_get_idt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
kvm_x86_ops->get_idt(emul_to_vcpu(ctxt), dt);
}
static void emulator_set_gdt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
kvm_x86_ops->set_gdt(emul_to_vcpu(ctxt), dt);
}
static void emulator_set_idt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
kvm_x86_ops->set_idt(emul_to_vcpu(ctxt), dt);
}
static unsigned long emulator_get_cached_segment_base(
struct x86_emulate_ctxt *ctxt, int seg)
{
return get_segment_base(emul_to_vcpu(ctxt), seg);
}
static bool emulator_get_segment(struct x86_emulate_ctxt *ctxt, u16 *selector,
struct desc_struct *desc, u32 *base3,
int seg)
{
struct kvm_segment var;
kvm_get_segment(emul_to_vcpu(ctxt), &var, seg);
*selector = var.selector;
if (var.unusable) {
memset(desc, 0, sizeof(*desc));
return false;
}
if (var.g)
var.limit >>= 12;
set_desc_limit(desc, var.limit);
set_desc_base(desc, (unsigned long)var.base);
#ifdef CONFIG_X86_64
if (base3)
*base3 = var.base >> 32;
#endif
desc->type = var.type;
desc->s = var.s;
desc->dpl = var.dpl;
desc->p = var.present;
desc->avl = var.avl;
desc->l = var.l;
desc->d = var.db;
desc->g = var.g;
return true;
}
static void emulator_set_segment(struct x86_emulate_ctxt *ctxt, u16 selector,
struct desc_struct *desc, u32 base3,
int seg)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
struct kvm_segment var;
var.selector = selector;
var.base = get_desc_base(desc);
#ifdef CONFIG_X86_64
var.base |= ((u64)base3) << 32;
#endif
var.limit = get_desc_limit(desc);
if (desc->g)
var.limit = (var.limit << 12) | 0xfff;
var.type = desc->type;
var.dpl = desc->dpl;
var.db = desc->d;
var.s = desc->s;
var.l = desc->l;
var.g = desc->g;
var.avl = desc->avl;
var.present = desc->p;
var.unusable = !var.present;
var.padding = 0;
kvm_set_segment(vcpu, &var, seg);
return;
}
static int emulator_get_msr(struct x86_emulate_ctxt *ctxt,
u32 msr_index, u64 *pdata)
{
struct msr_data msr;
int r;
msr.index = msr_index;
msr.host_initiated = false;
r = kvm_get_msr(emul_to_vcpu(ctxt), &msr);
if (r)
return r;
*pdata = msr.data;
return 0;
}
static int emulator_set_msr(struct x86_emulate_ctxt *ctxt,
u32 msr_index, u64 data)
{
struct msr_data msr;
msr.data = data;
msr.index = msr_index;
msr.host_initiated = false;
return kvm_set_msr(emul_to_vcpu(ctxt), &msr);
}
static u64 emulator_get_smbase(struct x86_emulate_ctxt *ctxt)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
return vcpu->arch.smbase;
}
static void emulator_set_smbase(struct x86_emulate_ctxt *ctxt, u64 smbase)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
vcpu->arch.smbase = smbase;
}
static int emulator_check_pmc(struct x86_emulate_ctxt *ctxt,
u32 pmc)
{
return kvm_pmu_is_valid_msr_idx(emul_to_vcpu(ctxt), pmc);
}
static int emulator_read_pmc(struct x86_emulate_ctxt *ctxt,
u32 pmc, u64 *pdata)
{
return kvm_pmu_rdpmc(emul_to_vcpu(ctxt), pmc, pdata);
}
static void emulator_halt(struct x86_emulate_ctxt *ctxt)
{
emul_to_vcpu(ctxt)->arch.halt_request = 1;
}
static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt)
{
preempt_disable();
kvm_load_guest_fpu(emul_to_vcpu(ctxt));
/*
* CR0.TS may reference the host fpu state, not the guest fpu state,
* so it may be clear at this point.
*/
clts();
}
static void emulator_put_fpu(struct x86_emulate_ctxt *ctxt)
{
preempt_enable();
}
static int emulator_intercept(struct x86_emulate_ctxt *ctxt,
struct x86_instruction_info *info,
enum x86_intercept_stage stage)
{
return kvm_x86_ops->check_intercept(emul_to_vcpu(ctxt), info, stage);
}
static void emulator_get_cpuid(struct x86_emulate_ctxt *ctxt,
u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
{
kvm_cpuid(emul_to_vcpu(ctxt), eax, ebx, ecx, edx);
}
static ulong emulator_read_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg)
{
return kvm_register_read(emul_to_vcpu(ctxt), reg);
}
static void emulator_write_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val)
{
kvm_register_write(emul_to_vcpu(ctxt), reg, val);
}
static void emulator_set_nmi_mask(struct x86_emulate_ctxt *ctxt, bool masked)
{
kvm_x86_ops->set_nmi_mask(emul_to_vcpu(ctxt), masked);
}
static const struct x86_emulate_ops emulate_ops = {
.read_gpr = emulator_read_gpr,
.write_gpr = emulator_write_gpr,
.read_std = kvm_read_guest_virt_system,
.write_std = kvm_write_guest_virt_system,
.fetch = kvm_fetch_guest_virt,
.read_emulated = emulator_read_emulated,
.write_emulated = emulator_write_emulated,
.cmpxchg_emulated = emulator_cmpxchg_emulated,
.invlpg = emulator_invlpg,
.pio_in_emulated = emulator_pio_in_emulated,
.pio_out_emulated = emulator_pio_out_emulated,
.get_segment = emulator_get_segment,
.set_segment = emulator_set_segment,
.get_cached_segment_base = emulator_get_cached_segment_base,
.get_gdt = emulator_get_gdt,
.get_idt = emulator_get_idt,
.set_gdt = emulator_set_gdt,
.set_idt = emulator_set_idt,
.get_cr = emulator_get_cr,
.set_cr = emulator_set_cr,
.cpl = emulator_get_cpl,
.get_dr = emulator_get_dr,
.set_dr = emulator_set_dr,
.get_smbase = emulator_get_smbase,
.set_smbase = emulator_set_smbase,
.set_msr = emulator_set_msr,
.get_msr = emulator_get_msr,
.check_pmc = emulator_check_pmc,
.read_pmc = emulator_read_pmc,
.halt = emulator_halt,
.wbinvd = emulator_wbinvd,
.fix_hypercall = emulator_fix_hypercall,
.get_fpu = emulator_get_fpu,
.put_fpu = emulator_put_fpu,
.intercept = emulator_intercept,
.get_cpuid = emulator_get_cpuid,
.set_nmi_mask = emulator_set_nmi_mask,
};
static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
{
u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(vcpu);
/*
* an sti; sti; sequence only disable interrupts for the first
* instruction. So, if the last instruction, be it emulated or
* not, left the system with the INT_STI flag enabled, it
* means that the last instruction is an sti. We should not
* leave the flag on in this case. The same goes for mov ss
*/
if (int_shadow & mask)
mask = 0;
if (unlikely(int_shadow || mask)) {
kvm_x86_ops->set_interrupt_shadow(vcpu, mask);
if (!mask)
kvm_make_request(KVM_REQ_EVENT, vcpu);
}
}
static bool inject_emulated_exception(struct kvm_vcpu *vcpu)
{
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
if (ctxt->exception.vector == PF_VECTOR)
return kvm_propagate_fault(vcpu, &ctxt->exception);
if (ctxt->exception.error_code_valid)
kvm_queue_exception_e(vcpu, ctxt->exception.vector,
ctxt->exception.error_code);
else
kvm_queue_exception(vcpu, ctxt->exception.vector);
return false;
}
static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
{
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
int cs_db, cs_l;
kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
ctxt->eflags = kvm_get_rflags(vcpu);
ctxt->eip = kvm_rip_read(vcpu);
ctxt->mode = (!is_protmode(vcpu)) ? X86EMUL_MODE_REAL :
(ctxt->eflags & X86_EFLAGS_VM) ? X86EMUL_MODE_VM86 :
(cs_l && is_long_mode(vcpu)) ? X86EMUL_MODE_PROT64 :
cs_db ? X86EMUL_MODE_PROT32 :
X86EMUL_MODE_PROT16;
BUILD_BUG_ON(HF_GUEST_MASK != X86EMUL_GUEST_MASK);
BUILD_BUG_ON(HF_SMM_MASK != X86EMUL_SMM_MASK);
BUILD_BUG_ON(HF_SMM_INSIDE_NMI_MASK != X86EMUL_SMM_INSIDE_NMI_MASK);
ctxt->emul_flags = vcpu->arch.hflags;
init_decode_cache(ctxt);
vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
}
int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip)
{
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
int ret;
init_emulate_ctxt(vcpu);
ctxt->op_bytes = 2;
ctxt->ad_bytes = 2;
ctxt->_eip = ctxt->eip + inc_eip;
ret = emulate_int_real(ctxt, irq);
if (ret != X86EMUL_CONTINUE)
return EMULATE_FAIL;
ctxt->eip = ctxt->_eip;
kvm_rip_write(vcpu, ctxt->eip);
kvm_set_rflags(vcpu, ctxt->eflags);
if (irq == NMI_VECTOR)
vcpu->arch.nmi_pending = 0;
else
vcpu->arch.interrupt.pending = false;
return EMULATE_DONE;
}
EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt);
static int handle_emulation_failure(struct kvm_vcpu *vcpu)
{
int r = EMULATE_DONE;
++vcpu->stat.insn_emulation_fail;
trace_kvm_emulate_insn_failed(vcpu);
if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) {
vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
vcpu->run->internal.ndata = 0;
r = EMULATE_FAIL;
}
kvm_queue_exception(vcpu, UD_VECTOR);
return r;
}
static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t cr2,
bool write_fault_to_shadow_pgtable,
int emulation_type)
{
gpa_t gpa = cr2;
pfn_t pfn;
if (emulation_type & EMULTYPE_NO_REEXECUTE)
return false;
if (!vcpu->arch.mmu.direct_map) {
/*
* Write permission should be allowed since only
* write access need to be emulated.
*/
gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL);
/*
* If the mapping is invalid in guest, let cpu retry
* it to generate fault.
*/
if (gpa == UNMAPPED_GVA)
return true;
}
/*
* Do not retry the unhandleable instruction if it faults on the
* readonly host memory, otherwise it will goto a infinite loop:
* retry instruction -> write #PF -> emulation fail -> retry
* instruction -> ...
*/
pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa));
/*
* If the instruction failed on the error pfn, it can not be fixed,
* report the error to userspace.
*/
if (is_error_noslot_pfn(pfn))
return false;
kvm_release_pfn_clean(pfn);
/* The instructions are well-emulated on direct mmu. */
if (vcpu->arch.mmu.direct_map) {
unsigned int indirect_shadow_pages;
spin_lock(&vcpu->kvm->mmu_lock);
indirect_shadow_pages = vcpu->kvm->arch.indirect_shadow_pages;
spin_unlock(&vcpu->kvm->mmu_lock);
if (indirect_shadow_pages)
kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
return true;
}
/*
* if emulation was due to access to shadowed page table
* and it failed try to unshadow page and re-enter the
* guest to let CPU execute the instruction.
*/
kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
/*
* If the access faults on its page table, it can not
* be fixed by unprotecting shadow page and it should
* be reported to userspace.
*/
return !write_fault_to_shadow_pgtable;
}
static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
unsigned long cr2, int emulation_type)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
unsigned long last_retry_eip, last_retry_addr, gpa = cr2;
last_retry_eip = vcpu->arch.last_retry_eip;
last_retry_addr = vcpu->arch.last_retry_addr;
/*
* If the emulation is caused by #PF and it is non-page_table
* writing instruction, it means the VM-EXIT is caused by shadow
* page protected, we can zap the shadow page and retry this
* instruction directly.
*
* Note: if the guest uses a non-page-table modifying instruction
* on the PDE that points to the instruction, then we will unmap
* the instruction and go to an infinite loop. So, we cache the
* last retried eip and the last fault address, if we meet the eip
* and the address again, we can break out of the potential infinite
* loop.
*/
vcpu->arch.last_retry_eip = vcpu->arch.last_retry_addr = 0;
if (!(emulation_type & EMULTYPE_RETRY))
return false;
if (x86_page_table_writing_insn(ctxt))
return false;
if (ctxt->eip == last_retry_eip && last_retry_addr == cr2)
return false;
vcpu->arch.last_retry_eip = ctxt->eip;
vcpu->arch.last_retry_addr = cr2;
if (!vcpu->arch.mmu.direct_map)
gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL);
kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
return true;
}
static int complete_emulated_mmio(struct kvm_vcpu *vcpu);
static int complete_emulated_pio(struct kvm_vcpu *vcpu);
static void kvm_smm_changed(struct kvm_vcpu *vcpu)
{
if (!(vcpu->arch.hflags & HF_SMM_MASK)) {
/* This is a good place to trace that we are exiting SMM. */
trace_kvm_enter_smm(vcpu->vcpu_id, vcpu->arch.smbase, false);
if (unlikely(vcpu->arch.smi_pending)) {
kvm_make_request(KVM_REQ_SMI, vcpu);
vcpu->arch.smi_pending = 0;
} else {
/* Process a latched INIT, if any. */
kvm_make_request(KVM_REQ_EVENT, vcpu);
}
}
kvm_mmu_reset_context(vcpu);
}
static void kvm_set_hflags(struct kvm_vcpu *vcpu, unsigned emul_flags)
{
unsigned changed = vcpu->arch.hflags ^ emul_flags;
vcpu->arch.hflags = emul_flags;
if (changed & HF_SMM_MASK)
kvm_smm_changed(vcpu);
}
static int kvm_vcpu_check_hw_bp(unsigned long addr, u32 type, u32 dr7,
unsigned long *db)
{
u32 dr6 = 0;
int i;
u32 enable, rwlen;
enable = dr7;
rwlen = dr7 >> 16;
for (i = 0; i < 4; i++, enable >>= 2, rwlen >>= 4)
if ((enable & 3) && (rwlen & 15) == type && db[i] == addr)
dr6 |= (1 << i);
return dr6;
}
static void kvm_vcpu_check_singlestep(struct kvm_vcpu *vcpu, unsigned long rflags, int *r)
{
struct kvm_run *kvm_run = vcpu->run;
/*
* rflags is the old, "raw" value of the flags. The new value has
* not been saved yet.
*
* This is correct even for TF set by the guest, because "the
* processor will not generate this exception after the instruction
* that sets the TF flag".
*/
if (unlikely(rflags & X86_EFLAGS_TF)) {
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
kvm_run->debug.arch.dr6 = DR6_BS | DR6_FIXED_1 |
DR6_RTM;
kvm_run->debug.arch.pc = vcpu->arch.singlestep_rip;
kvm_run->debug.arch.exception = DB_VECTOR;
kvm_run->exit_reason = KVM_EXIT_DEBUG;
*r = EMULATE_USER_EXIT;
} else {
vcpu->arch.emulate_ctxt.eflags &= ~X86_EFLAGS_TF;
/*
* "Certain debug exceptions may clear bit 0-3. The
* remaining contents of the DR6 register are never
* cleared by the processor".
*/
vcpu->arch.dr6 &= ~15;
vcpu->arch.dr6 |= DR6_BS | DR6_RTM;
kvm_queue_exception(vcpu, DB_VECTOR);
}
}
}
static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r)
{
if (unlikely(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) &&
(vcpu->arch.guest_debug_dr7 & DR7_BP_EN_MASK)) {
struct kvm_run *kvm_run = vcpu->run;
unsigned long eip = kvm_get_linear_rip(vcpu);
u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0,
vcpu->arch.guest_debug_dr7,
vcpu->arch.eff_db);
if (dr6 != 0) {
kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1 | DR6_RTM;
kvm_run->debug.arch.pc = eip;
kvm_run->debug.arch.exception = DB_VECTOR;
kvm_run->exit_reason = KVM_EXIT_DEBUG;
*r = EMULATE_USER_EXIT;
return true;
}
}
if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK) &&
!(kvm_get_rflags(vcpu) & X86_EFLAGS_RF)) {
unsigned long eip = kvm_get_linear_rip(vcpu);
u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0,
vcpu->arch.dr7,
vcpu->arch.db);
if (dr6 != 0) {
vcpu->arch.dr6 &= ~15;
vcpu->arch.dr6 |= dr6 | DR6_RTM;
kvm_queue_exception(vcpu, DB_VECTOR);
*r = EMULATE_DONE;
return true;
}
}
return false;
}
int x86_emulate_instruction(struct kvm_vcpu *vcpu,
unsigned long cr2,
int emulation_type,
void *insn,
int insn_len)
{
int r;
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
bool writeback = true;
bool write_fault_to_spt = vcpu->arch.write_fault_to_shadow_pgtable;
/*
* Clear write_fault_to_shadow_pgtable here to ensure it is
* never reused.
*/
vcpu->arch.write_fault_to_shadow_pgtable = false;
kvm_clear_exception_queue(vcpu);
if (!(emulation_type & EMULTYPE_NO_DECODE)) {
init_emulate_ctxt(vcpu);
/*
* We will reenter on the same instruction since
* we do not set complete_userspace_io. This does not
* handle watchpoints yet, those would be handled in
* the emulate_ops.
*/
if (kvm_vcpu_check_breakpoint(vcpu, &r))
return r;
ctxt->interruptibility = 0;
ctxt->have_exception = false;
ctxt->exception.vector = -1;
ctxt->perm_ok = false;
ctxt->ud = emulation_type & EMULTYPE_TRAP_UD;
r = x86_decode_insn(ctxt, insn, insn_len);
trace_kvm_emulate_insn_start(vcpu);
++vcpu->stat.insn_emulation;
if (r != EMULATION_OK) {
if (emulation_type & EMULTYPE_TRAP_UD)
return EMULATE_FAIL;
if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
emulation_type))
return EMULATE_DONE;
if (emulation_type & EMULTYPE_SKIP)
return EMULATE_FAIL;
return handle_emulation_failure(vcpu);
}
}
if (emulation_type & EMULTYPE_SKIP) {
kvm_rip_write(vcpu, ctxt->_eip);
if (ctxt->eflags & X86_EFLAGS_RF)
kvm_set_rflags(vcpu, ctxt->eflags & ~X86_EFLAGS_RF);
return EMULATE_DONE;
}
if (retry_instruction(ctxt, cr2, emulation_type))
return EMULATE_DONE;
/* this is needed for vmware backdoor interface to work since it
changes registers values during IO operation */
if (vcpu->arch.emulate_regs_need_sync_from_vcpu) {
vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
emulator_invalidate_register_cache(ctxt);
}
restart:
r = x86_emulate_insn(ctxt);
if (r == EMULATION_INTERCEPTED)
return EMULATE_DONE;
if (r == EMULATION_FAILED) {
if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
emulation_type))
return EMULATE_DONE;
return handle_emulation_failure(vcpu);
}
if (ctxt->have_exception) {
r = EMULATE_DONE;
if (inject_emulated_exception(vcpu))
return r;
} else if (vcpu->arch.pio.count) {
if (!vcpu->arch.pio.in) {
/* FIXME: return into emulator if single-stepping. */
vcpu->arch.pio.count = 0;
} else {
writeback = false;
vcpu->arch.complete_userspace_io = complete_emulated_pio;
}
r = EMULATE_USER_EXIT;
} else if (vcpu->mmio_needed) {
if (!vcpu->mmio_is_write)
writeback = false;
r = EMULATE_USER_EXIT;
vcpu->arch.complete_userspace_io = complete_emulated_mmio;
} else if (r == EMULATION_RESTART)
goto restart;
else
r = EMULATE_DONE;
if (writeback) {
unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
toggle_interruptibility(vcpu, ctxt->interruptibility);
vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
if (vcpu->arch.hflags != ctxt->emul_flags)
kvm_set_hflags(vcpu, ctxt->emul_flags);
kvm_rip_write(vcpu, ctxt->eip);
if (r == EMULATE_DONE)
kvm_vcpu_check_singlestep(vcpu, rflags, &r);
if (!ctxt->have_exception ||
exception_type(ctxt->exception.vector) == EXCPT_TRAP)
__kvm_set_rflags(vcpu, ctxt->eflags);
/*
* For STI, interrupts are shadowed; so KVM_REQ_EVENT will
* do nothing, and it will be requested again as soon as
* the shadow expires. But we still need to check here,
* because POPF has no interrupt shadow.
*/
if (unlikely((ctxt->eflags & ~rflags) & X86_EFLAGS_IF))
kvm_make_request(KVM_REQ_EVENT, vcpu);
} else
vcpu->arch.emulate_regs_need_sync_to_vcpu = true;
return r;
}
EXPORT_SYMBOL_GPL(x86_emulate_instruction);
int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port)
{
unsigned long val = kvm_register_read(vcpu, VCPU_REGS_RAX);
int ret = emulator_pio_out_emulated(&vcpu->arch.emulate_ctxt,
size, port, &val, 1);
/* do not return to emulator after return from userspace */
vcpu->arch.pio.count = 0;
return ret;
}
EXPORT_SYMBOL_GPL(kvm_fast_pio_out);
static void tsc_bad(void *info)
{
__this_cpu_write(cpu_tsc_khz, 0);
}
static void tsc_khz_changed(void *data)
{
struct cpufreq_freqs *freq = data;
unsigned long khz = 0;
if (data)
khz = freq->new;
else if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
khz = cpufreq_quick_get(raw_smp_processor_id());
if (!khz)
khz = tsc_khz;
__this_cpu_write(cpu_tsc_khz, khz);
}
static int kvmclock_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
struct cpufreq_freqs *freq = data;
struct kvm *kvm;
struct kvm_vcpu *vcpu;
int i, send_ipi = 0;
/*
* We allow guests to temporarily run on slowing clocks,
* provided we notify them after, or to run on accelerating
* clocks, provided we notify them before. Thus time never
* goes backwards.
*
* However, we have a problem. We can't atomically update
* the frequency of a given CPU from this function; it is
* merely a notifier, which can be called from any CPU.
* Changing the TSC frequency at arbitrary points in time
* requires a recomputation of local variables related to
* the TSC for each VCPU. We must flag these local variables
* to be updated and be sure the update takes place with the
* new frequency before any guests proceed.
*
* Unfortunately, the combination of hotplug CPU and frequency
* change creates an intractable locking scenario; the order
* of when these callouts happen is undefined with respect to
* CPU hotplug, and they can race with each other. As such,
* merely setting per_cpu(cpu_tsc_khz) = X during a hotadd is
* undefined; you can actually have a CPU frequency change take
* place in between the computation of X and the setting of the
* variable. To protect against this problem, all updates of
* the per_cpu tsc_khz variable are done in an interrupt
* protected IPI, and all callers wishing to update the value
* must wait for a synchronous IPI to complete (which is trivial
* if the caller is on the CPU already). This establishes the
* necessary total order on variable updates.
*
* Note that because a guest time update may take place
* anytime after the setting of the VCPU's request bit, the
* correct TSC value must be set before the request. However,
* to ensure the update actually makes it to any guest which
* starts running in hardware virtualization between the set
* and the acquisition of the spinlock, we must also ping the
* CPU after setting the request bit.
*
*/
if (val == CPUFREQ_PRECHANGE && freq->old > freq->new)
return 0;
if (val == CPUFREQ_POSTCHANGE && freq->old < freq->new)
return 0;
smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1);
KVM: Convert kvm_lock back to non-raw spinlock In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"), the kvm_lock was made a raw lock. However, the kvm mmu_shrink() function tries to grab the (non-raw) mmu_lock within the scope of the raw locked kvm_lock being held. This leads to the following: BUG: sleeping function called from invalid context at kernel/rtmutex.c:659 in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0 Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm] Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt Call Trace: [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm] [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0 [<ffffffff811185bf>] kswapd+0x18f/0x490 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730 [<ffffffff81060d2b>] kthread+0xdb/0xe0 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10 [<ffffffff81060c50>] ? __init_kthread_worker+0x After the previous patch, kvm_lock need not be a raw spinlock anymore, so change it back. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: kvm@vger.kernel.org Cc: gleb@redhat.com Cc: jan.kiszka@siemens.com Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-25 11:53:07 +00:00
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_for_each_vcpu(i, vcpu, kvm) {
if (vcpu->cpu != freq->cpu)
continue;
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
if (vcpu->cpu != smp_processor_id())
send_ipi = 1;
}
}
KVM: Convert kvm_lock back to non-raw spinlock In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"), the kvm_lock was made a raw lock. However, the kvm mmu_shrink() function tries to grab the (non-raw) mmu_lock within the scope of the raw locked kvm_lock being held. This leads to the following: BUG: sleeping function called from invalid context at kernel/rtmutex.c:659 in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0 Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm] Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt Call Trace: [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm] [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0 [<ffffffff811185bf>] kswapd+0x18f/0x490 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730 [<ffffffff81060d2b>] kthread+0xdb/0xe0 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10 [<ffffffff81060c50>] ? __init_kthread_worker+0x After the previous patch, kvm_lock need not be a raw spinlock anymore, so change it back. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: kvm@vger.kernel.org Cc: gleb@redhat.com Cc: jan.kiszka@siemens.com Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-25 11:53:07 +00:00
spin_unlock(&kvm_lock);
if (freq->old < freq->new && send_ipi) {
/*
* We upscale the frequency. Must make the guest
* doesn't see old kvmclock values while running with
* the new frequency, otherwise we risk the guest sees
* time go backwards.
*
* In case we update the frequency for another cpu
* (which might be in guest context) send an interrupt
* to kick the cpu out of guest context. Next time
* guest context is entered kvmclock will be updated,
* so the guest will not see stale values.
*/
smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1);
}
return 0;
}
static struct notifier_block kvmclock_cpufreq_notifier_block = {
.notifier_call = kvmclock_cpufreq_notifier
};
static int kvmclock_cpu_notifier(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
break;
case CPU_DOWN_PREPARE:
smp_call_function_single(cpu, tsc_bad, NULL, 1);
break;
}
return NOTIFY_OK;
}
static struct notifier_block kvmclock_cpu_notifier_block = {
.notifier_call = kvmclock_cpu_notifier,
.priority = -INT_MAX
};
static void kvm_timer_init(void)
{
int cpu;
max_tsc_khz = tsc_khz;
cpu_notifier_register_begin();
if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
#ifdef CONFIG_CPU_FREQ
struct cpufreq_policy policy;
memset(&policy, 0, sizeof(policy));
cpu = get_cpu();
cpufreq_get_policy(&policy, cpu);
if (policy.cpuinfo.max_freq)
max_tsc_khz = policy.cpuinfo.max_freq;
put_cpu();
#endif
cpufreq_register_notifier(&kvmclock_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
pr_debug("kvm: max_tsc_khz = %ld\n", max_tsc_khz);
for_each_online_cpu(cpu)
smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
__register_hotcpu_notifier(&kvmclock_cpu_notifier_block);
cpu_notifier_register_done();
}
static DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);
int kvm_is_in_guest(void)
{
return __this_cpu_read(current_vcpu) != NULL;
}
static int kvm_is_user_mode(void)
{
int user_mode = 3;
if (__this_cpu_read(current_vcpu))
user_mode = kvm_x86_ops->get_cpl(__this_cpu_read(current_vcpu));
return user_mode != 0;
}
static unsigned long kvm_get_guest_ip(void)
{
unsigned long ip = 0;
if (__this_cpu_read(current_vcpu))
ip = kvm_rip_read(__this_cpu_read(current_vcpu));
return ip;
}
static struct perf_guest_info_callbacks kvm_guest_cbs = {
.is_in_guest = kvm_is_in_guest,
.is_user_mode = kvm_is_user_mode,
.get_guest_ip = kvm_get_guest_ip,
};
void kvm_before_handle_nmi(struct kvm_vcpu *vcpu)
{
__this_cpu_write(current_vcpu, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_before_handle_nmi);
void kvm_after_handle_nmi(struct kvm_vcpu *vcpu)
{
__this_cpu_write(current_vcpu, NULL);
}
EXPORT_SYMBOL_GPL(kvm_after_handle_nmi);
static void kvm_set_mmio_spte_mask(void)
{
u64 mask;
int maxphyaddr = boot_cpu_data.x86_phys_bits;
/*
* Set the reserved bits and the present bit of an paging-structure
* entry to generate page fault with PFER.RSV = 1.
*/
/* Mask the reserved physical address bits. */
mask = rsvd_bits(maxphyaddr, 51);
/* Bit 62 is always reserved for 32bit host. */
mask |= 0x3ull << 62;
/* Set the present bit. */
mask |= 1ull;
#ifdef CONFIG_X86_64
/*
* If reserved bit is not supported, clear the present bit to disable
* mmio page fault.
*/
if (maxphyaddr == 52)
mask &= ~1ull;
#endif
kvm_mmu_set_mmio_spte_mask(mask);
}
#ifdef CONFIG_X86_64
static void pvclock_gtod_update_fn(struct work_struct *work)
{
struct kvm *kvm;
struct kvm_vcpu *vcpu;
int i;
KVM: Convert kvm_lock back to non-raw spinlock In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"), the kvm_lock was made a raw lock. However, the kvm mmu_shrink() function tries to grab the (non-raw) mmu_lock within the scope of the raw locked kvm_lock being held. This leads to the following: BUG: sleeping function called from invalid context at kernel/rtmutex.c:659 in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0 Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm] Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt Call Trace: [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm] [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0 [<ffffffff811185bf>] kswapd+0x18f/0x490 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730 [<ffffffff81060d2b>] kthread+0xdb/0xe0 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10 [<ffffffff81060c50>] ? __init_kthread_worker+0x After the previous patch, kvm_lock need not be a raw spinlock anymore, so change it back. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: kvm@vger.kernel.org Cc: gleb@redhat.com Cc: jan.kiszka@siemens.com Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-25 11:53:07 +00:00
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list)
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
atomic_set(&kvm_guest_has_master_clock, 0);
KVM: Convert kvm_lock back to non-raw spinlock In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"), the kvm_lock was made a raw lock. However, the kvm mmu_shrink() function tries to grab the (non-raw) mmu_lock within the scope of the raw locked kvm_lock being held. This leads to the following: BUG: sleeping function called from invalid context at kernel/rtmutex.c:659 in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0 Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm] Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt Call Trace: [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm] [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0 [<ffffffff811185bf>] kswapd+0x18f/0x490 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730 [<ffffffff81060d2b>] kthread+0xdb/0xe0 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10 [<ffffffff81060c50>] ? __init_kthread_worker+0x After the previous patch, kvm_lock need not be a raw spinlock anymore, so change it back. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: kvm@vger.kernel.org Cc: gleb@redhat.com Cc: jan.kiszka@siemens.com Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-25 11:53:07 +00:00
spin_unlock(&kvm_lock);
}
static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn);
/*
* Notification about pvclock gtod data update.
*/
static int pvclock_gtod_notify(struct notifier_block *nb, unsigned long unused,
void *priv)
{
struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
struct timekeeper *tk = priv;
update_pvclock_gtod(tk);
/* disable master clock if host does not trust, or does not
* use, TSC clocksource
*/
if (gtod->clock.vclock_mode != VCLOCK_TSC &&
atomic_read(&kvm_guest_has_master_clock) != 0)
queue_work(system_long_wq, &pvclock_gtod_work);
return 0;
}
static struct notifier_block pvclock_gtod_notifier = {
.notifier_call = pvclock_gtod_notify,
};
#endif
int kvm_arch_init(void *opaque)
{
int r;
struct kvm_x86_ops *ops = opaque;
if (kvm_x86_ops) {
printk(KERN_ERR "kvm: already loaded the other module\n");
r = -EEXIST;
goto out;
}
if (!ops->cpu_has_kvm_support()) {
printk(KERN_ERR "kvm: no hardware support\n");
r = -EOPNOTSUPP;
goto out;
}
if (ops->disabled_by_bios()) {
printk(KERN_ERR "kvm: disabled by bios\n");
r = -EOPNOTSUPP;
goto out;
}
r = -ENOMEM;
shared_msrs = alloc_percpu(struct kvm_shared_msrs);
if (!shared_msrs) {
printk(KERN_ERR "kvm: failed to allocate percpu kvm_shared_msrs\n");
goto out;
}
r = kvm_mmu_module_init();
if (r)
goto out_free_percpu;
kvm_set_mmio_spte_mask();
kvm_x86_ops = ops;
kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK,
PT_DIRTY_MASK, PT64_NX_MASK, 0);
kvm_timer_init();
perf_register_guest_info_callbacks(&kvm_guest_cbs);
if (cpu_has_xsave)
host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
kvm_lapic_init();
#ifdef CONFIG_X86_64
pvclock_gtod_register_notifier(&pvclock_gtod_notifier);
#endif
return 0;
out_free_percpu:
free_percpu(shared_msrs);
out:
return r;
}
void kvm_arch_exit(void)
{
perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
unregister_hotcpu_notifier(&kvmclock_cpu_notifier_block);
#ifdef CONFIG_X86_64
pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier);
#endif
kvm_x86_ops = NULL;
kvm_mmu_module_exit();
free_percpu(shared_msrs);
}
int kvm_vcpu_halt(struct kvm_vcpu *vcpu)
{
++vcpu->stat.halt_exits;
if (irqchip_in_kernel(vcpu->kvm)) {
vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
return 1;
} else {
vcpu->run->exit_reason = KVM_EXIT_HLT;
return 0;
}
}
EXPORT_SYMBOL_GPL(kvm_vcpu_halt);
int kvm_emulate_halt(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->skip_emulated_instruction(vcpu);
return kvm_vcpu_halt(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_halt);
/*
* kvm_pv_kick_cpu_op: Kick a vcpu.
*
* @apicid - apicid of vcpu to be kicked.
*/
static void kvm_pv_kick_cpu_op(struct kvm *kvm, unsigned long flags, int apicid)
{
struct kvm_lapic_irq lapic_irq;
lapic_irq.shorthand = 0;
lapic_irq.dest_mode = 0;
lapic_irq.dest_id = apicid;
lapic_irq.msi_redir_hint = false;
lapic_irq.delivery_mode = APIC_DM_REMRD;
kvm_irq_delivery_to_apic(kvm, NULL, &lapic_irq, NULL);
}
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
unsigned long nr, a0, a1, a2, a3, ret;
int op_64_bit, r = 1;
kvm_x86_ops->skip_emulated_instruction(vcpu);
if (kvm_hv_hypercall_enabled(vcpu->kvm))
return kvm_hv_hypercall(vcpu);
nr = kvm_register_read(vcpu, VCPU_REGS_RAX);
a0 = kvm_register_read(vcpu, VCPU_REGS_RBX);
a1 = kvm_register_read(vcpu, VCPU_REGS_RCX);
a2 = kvm_register_read(vcpu, VCPU_REGS_RDX);
a3 = kvm_register_read(vcpu, VCPU_REGS_RSI);
trace_kvm_hypercall(nr, a0, a1, a2, a3);
op_64_bit = is_64_bit_mode(vcpu);
if (!op_64_bit) {
nr &= 0xFFFFFFFF;
a0 &= 0xFFFFFFFF;
a1 &= 0xFFFFFFFF;
a2 &= 0xFFFFFFFF;
a3 &= 0xFFFFFFFF;
}
if (kvm_x86_ops->get_cpl(vcpu) != 0) {
ret = -KVM_EPERM;
goto out;
}
switch (nr) {
case KVM_HC_VAPIC_POLL_IRQ:
ret = 0;
break;
case KVM_HC_KICK_CPU:
kvm_pv_kick_cpu_op(vcpu->kvm, a0, a1);
ret = 0;
break;
default:
ret = -KVM_ENOSYS;
break;
}
out:
if (!op_64_bit)
ret = (u32)ret;
kvm_register_write(vcpu, VCPU_REGS_RAX, ret);
++vcpu->stat.hypercalls;
return r;
}
EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);
static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
char instruction[3];
unsigned long rip = kvm_rip_read(vcpu);
kvm_x86_ops->patch_hypercall(vcpu, instruction);
return emulator_write_emulated(ctxt, rip, instruction, 3, NULL);
}
/*
* Check if userspace requested an interrupt window, and that the
* interrupt window is open.
*
* No need to exit to userspace if we already have an interrupt queued.
*/
static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
{
return (!irqchip_in_kernel(vcpu->kvm) && !kvm_cpu_has_interrupt(vcpu) &&
vcpu->run->request_interrupt_window &&
kvm_arch_interrupt_allowed(vcpu));
}
static void post_kvm_run_save(struct kvm_vcpu *vcpu)
{
struct kvm_run *kvm_run = vcpu->run;
kvm_run->if_flag = (kvm_get_rflags(vcpu) & X86_EFLAGS_IF) != 0;
kvm_run->flags = is_smm(vcpu) ? KVM_RUN_X86_SMM : 0;
kvm_run->cr8 = kvm_get_cr8(vcpu);
kvm_run->apic_base = kvm_get_apic_base(vcpu);
if (irqchip_in_kernel(vcpu->kvm))
kvm_run->ready_for_interrupt_injection = 1;
else
kvm_run->ready_for_interrupt_injection =
kvm_arch_interrupt_allowed(vcpu) &&
!kvm_cpu_has_interrupt(vcpu) &&
!kvm_event_needs_reinjection(vcpu);
}
static void update_cr8_intercept(struct kvm_vcpu *vcpu)
{
int max_irr, tpr;
if (!kvm_x86_ops->update_cr8_intercept)
return;
if (!vcpu->arch.apic)
return;
if (!vcpu->arch.apic->vapic_addr)
max_irr = kvm_lapic_find_highest_irr(vcpu);
else
max_irr = -1;
if (max_irr != -1)
max_irr >>= 4;
tpr = kvm_lapic_get_cr8(vcpu);
kvm_x86_ops->update_cr8_intercept(vcpu, tpr, max_irr);
}
static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
{
int r;
/* try to reinject previous events if any */
if (vcpu->arch.exception.pending) {
trace_kvm_inj_exception(vcpu->arch.exception.nr,
vcpu->arch.exception.has_error_code,
vcpu->arch.exception.error_code);
if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT)
__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
X86_EFLAGS_RF);
if (vcpu->arch.exception.nr == DB_VECTOR &&
(vcpu->arch.dr7 & DR7_GD)) {
vcpu->arch.dr7 &= ~DR7_GD;
kvm_update_dr7(vcpu);
}
kvm_x86_ops->queue_exception(vcpu, vcpu->arch.exception.nr,
vcpu->arch.exception.has_error_code,
vcpu->arch.exception.error_code,
vcpu->arch.exception.reinject);
return 0;
}
if (vcpu->arch.nmi_injected) {
kvm_x86_ops->set_nmi(vcpu);
return 0;
}
if (vcpu->arch.interrupt.pending) {
kvm_x86_ops->set_irq(vcpu);
return 0;
}
if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) {
r = kvm_x86_ops->check_nested_events(vcpu, req_int_win);
if (r != 0)
return r;
}
/* try to inject new event if pending */
if (vcpu->arch.nmi_pending) {
if (kvm_x86_ops->nmi_allowed(vcpu)) {
--vcpu->arch.nmi_pending;
vcpu->arch.nmi_injected = true;
kvm_x86_ops->set_nmi(vcpu);
}
} else if (kvm_cpu_has_injectable_intr(vcpu)) {
/*
* Because interrupts can be injected asynchronously, we are
* calling check_nested_events again here to avoid a race condition.
* See https://lkml.org/lkml/2014/7/2/60 for discussion about this
* proposal and current concerns. Perhaps we should be setting
* KVM_REQ_EVENT only on certain events and not unconditionally?
*/
if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) {
r = kvm_x86_ops->check_nested_events(vcpu, req_int_win);
if (r != 0)
return r;
}
if (kvm_x86_ops->interrupt_allowed(vcpu)) {
kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
false);
kvm_x86_ops->set_irq(vcpu);
}
}
return 0;
}
static void process_nmi(struct kvm_vcpu *vcpu)
{
unsigned limit = 2;
/*
* x86 is limited to one NMI running, and one NMI pending after it.
* If an NMI is already in progress, limit further NMIs to just one.
* Otherwise, allow two (and we'll inject the first one immediately).
*/
if (kvm_x86_ops->get_nmi_mask(vcpu) || vcpu->arch.nmi_injected)
limit = 1;
vcpu->arch.nmi_pending += atomic_xchg(&vcpu->arch.nmi_queued, 0);
vcpu->arch.nmi_pending = min(vcpu->arch.nmi_pending, limit);
kvm_make_request(KVM_REQ_EVENT, vcpu);
}
#define put_smstate(type, buf, offset, val) \
*(type *)((buf) + (offset) - 0x7e00) = val
static u32 process_smi_get_segment_flags(struct kvm_segment *seg)
{
u32 flags = 0;
flags |= seg->g << 23;
flags |= seg->db << 22;
flags |= seg->l << 21;
flags |= seg->avl << 20;
flags |= seg->present << 15;
flags |= seg->dpl << 13;
flags |= seg->s << 12;
flags |= seg->type << 8;
return flags;
}
static void process_smi_save_seg_32(struct kvm_vcpu *vcpu, char *buf, int n)
{
struct kvm_segment seg;
int offset;
kvm_get_segment(vcpu, &seg, n);
put_smstate(u32, buf, 0x7fa8 + n * 4, seg.selector);
if (n < 3)
offset = 0x7f84 + n * 12;
else
offset = 0x7f2c + (n - 3) * 12;
put_smstate(u32, buf, offset + 8, seg.base);
put_smstate(u32, buf, offset + 4, seg.limit);
put_smstate(u32, buf, offset, process_smi_get_segment_flags(&seg));
}
#ifdef CONFIG_X86_64
static void process_smi_save_seg_64(struct kvm_vcpu *vcpu, char *buf, int n)
{
struct kvm_segment seg;
int offset;
u16 flags;
kvm_get_segment(vcpu, &seg, n);
offset = 0x7e00 + n * 16;
flags = process_smi_get_segment_flags(&seg) >> 8;
put_smstate(u16, buf, offset, seg.selector);
put_smstate(u16, buf, offset + 2, flags);
put_smstate(u32, buf, offset + 4, seg.limit);
put_smstate(u64, buf, offset + 8, seg.base);
}
#endif
static void process_smi_save_state_32(struct kvm_vcpu *vcpu, char *buf)
{
struct desc_ptr dt;
struct kvm_segment seg;
unsigned long val;
int i;
put_smstate(u32, buf, 0x7ffc, kvm_read_cr0(vcpu));
put_smstate(u32, buf, 0x7ff8, kvm_read_cr3(vcpu));
put_smstate(u32, buf, 0x7ff4, kvm_get_rflags(vcpu));
put_smstate(u32, buf, 0x7ff0, kvm_rip_read(vcpu));
for (i = 0; i < 8; i++)
put_smstate(u32, buf, 0x7fd0 + i * 4, kvm_register_read(vcpu, i));
kvm_get_dr(vcpu, 6, &val);
put_smstate(u32, buf, 0x7fcc, (u32)val);
kvm_get_dr(vcpu, 7, &val);
put_smstate(u32, buf, 0x7fc8, (u32)val);
kvm_get_segment(vcpu, &seg, VCPU_SREG_TR);
put_smstate(u32, buf, 0x7fc4, seg.selector);
put_smstate(u32, buf, 0x7f64, seg.base);
put_smstate(u32, buf, 0x7f60, seg.limit);
put_smstate(u32, buf, 0x7f5c, process_smi_get_segment_flags(&seg));
kvm_get_segment(vcpu, &seg, VCPU_SREG_LDTR);
put_smstate(u32, buf, 0x7fc0, seg.selector);
put_smstate(u32, buf, 0x7f80, seg.base);
put_smstate(u32, buf, 0x7f7c, seg.limit);
put_smstate(u32, buf, 0x7f78, process_smi_get_segment_flags(&seg));
kvm_x86_ops->get_gdt(vcpu, &dt);
put_smstate(u32, buf, 0x7f74, dt.address);
put_smstate(u32, buf, 0x7f70, dt.size);
kvm_x86_ops->get_idt(vcpu, &dt);
put_smstate(u32, buf, 0x7f58, dt.address);
put_smstate(u32, buf, 0x7f54, dt.size);
for (i = 0; i < 6; i++)
process_smi_save_seg_32(vcpu, buf, i);
put_smstate(u32, buf, 0x7f14, kvm_read_cr4(vcpu));
/* revision id */
put_smstate(u32, buf, 0x7efc, 0x00020000);
put_smstate(u32, buf, 0x7ef8, vcpu->arch.smbase);
}
static void process_smi_save_state_64(struct kvm_vcpu *vcpu, char *buf)
{
#ifdef CONFIG_X86_64
struct desc_ptr dt;
struct kvm_segment seg;
unsigned long val;
int i;
for (i = 0; i < 16; i++)
put_smstate(u64, buf, 0x7ff8 - i * 8, kvm_register_read(vcpu, i));
put_smstate(u64, buf, 0x7f78, kvm_rip_read(vcpu));
put_smstate(u32, buf, 0x7f70, kvm_get_rflags(vcpu));
kvm_get_dr(vcpu, 6, &val);
put_smstate(u64, buf, 0x7f68, val);
kvm_get_dr(vcpu, 7, &val);
put_smstate(u64, buf, 0x7f60, val);
put_smstate(u64, buf, 0x7f58, kvm_read_cr0(vcpu));
put_smstate(u64, buf, 0x7f50, kvm_read_cr3(vcpu));
put_smstate(u64, buf, 0x7f48, kvm_read_cr4(vcpu));
put_smstate(u32, buf, 0x7f00, vcpu->arch.smbase);
/* revision id */
put_smstate(u32, buf, 0x7efc, 0x00020064);
put_smstate(u64, buf, 0x7ed0, vcpu->arch.efer);
kvm_get_segment(vcpu, &seg, VCPU_SREG_TR);
put_smstate(u16, buf, 0x7e90, seg.selector);
put_smstate(u16, buf, 0x7e92, process_smi_get_segment_flags(&seg) >> 8);
put_smstate(u32, buf, 0x7e94, seg.limit);
put_smstate(u64, buf, 0x7e98, seg.base);
kvm_x86_ops->get_idt(vcpu, &dt);
put_smstate(u32, buf, 0x7e84, dt.size);
put_smstate(u64, buf, 0x7e88, dt.address);
kvm_get_segment(vcpu, &seg, VCPU_SREG_LDTR);
put_smstate(u16, buf, 0x7e70, seg.selector);
put_smstate(u16, buf, 0x7e72, process_smi_get_segment_flags(&seg) >> 8);
put_smstate(u32, buf, 0x7e74, seg.limit);
put_smstate(u64, buf, 0x7e78, seg.base);
kvm_x86_ops->get_gdt(vcpu, &dt);
put_smstate(u32, buf, 0x7e64, dt.size);
put_smstate(u64, buf, 0x7e68, dt.address);
for (i = 0; i < 6; i++)
process_smi_save_seg_64(vcpu, buf, i);
#else
WARN_ON_ONCE(1);
#endif
}
static void process_smi(struct kvm_vcpu *vcpu)
{
struct kvm_segment cs, ds;
struct desc_ptr dt;
char buf[512];
u32 cr0;
if (is_smm(vcpu)) {
vcpu->arch.smi_pending = true;
return;
}
trace_kvm_enter_smm(vcpu->vcpu_id, vcpu->arch.smbase, true);
vcpu->arch.hflags |= HF_SMM_MASK;
memset(buf, 0, 512);
if (guest_cpuid_has_longmode(vcpu))
process_smi_save_state_64(vcpu, buf);
else
process_smi_save_state_32(vcpu, buf);
kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf));
if (kvm_x86_ops->get_nmi_mask(vcpu))
vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
else
kvm_x86_ops->set_nmi_mask(vcpu, true);
kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
kvm_rip_write(vcpu, 0x8000);
cr0 = vcpu->arch.cr0 & ~(X86_CR0_PE | X86_CR0_EM | X86_CR0_TS | X86_CR0_PG);
kvm_x86_ops->set_cr0(vcpu, cr0);
vcpu->arch.cr0 = cr0;
kvm_x86_ops->set_cr4(vcpu, 0);
/* Undocumented: IDT limit is set to zero on entry to SMM. */
dt.address = dt.size = 0;
kvm_x86_ops->set_idt(vcpu, &dt);
__kvm_set_dr(vcpu, 7, DR7_FIXED_1);
cs.selector = (vcpu->arch.smbase >> 4) & 0xffff;
cs.base = vcpu->arch.smbase;
ds.selector = 0;
ds.base = 0;
cs.limit = ds.limit = 0xffffffff;
cs.type = ds.type = 0x3;
cs.dpl = ds.dpl = 0;
cs.db = ds.db = 0;
cs.s = ds.s = 1;
cs.l = ds.l = 0;
cs.g = ds.g = 1;
cs.avl = ds.avl = 0;
cs.present = ds.present = 1;
cs.unusable = ds.unusable = 0;
cs.padding = ds.padding = 0;
kvm_set_segment(vcpu, &cs, VCPU_SREG_CS);
kvm_set_segment(vcpu, &ds, VCPU_SREG_DS);
kvm_set_segment(vcpu, &ds, VCPU_SREG_ES);
kvm_set_segment(vcpu, &ds, VCPU_SREG_FS);
kvm_set_segment(vcpu, &ds, VCPU_SREG_GS);
kvm_set_segment(vcpu, &ds, VCPU_SREG_SS);
if (guest_cpuid_has_longmode(vcpu))
kvm_x86_ops->set_efer(vcpu, 0);
kvm_update_cpuid(vcpu);
kvm_mmu_reset_context(vcpu);
}
static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
{
u64 eoi_exit_bitmap[4];
u32 tmr[8];
if (!kvm_apic_hw_enabled(vcpu->arch.apic))
return;
memset(eoi_exit_bitmap, 0, 32);
memset(tmr, 0, 32);
kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
kvm_apic_update_tmr(vcpu, tmr);
}
static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
{
++vcpu->stat.tlb_flush;
kvm_x86_ops->tlb_flush(vcpu);
}
void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
{
struct page *page = NULL;
kvm: do not handle APIC access page if in-kernel irqchip is not in use This fixes the following OOPS: loaded kvm module (v3.17-rc1-168-gcec26bc) BUG: unable to handle kernel paging request at fffffffffffffffe IP: [<ffffffff81168449>] put_page+0x9/0x30 PGD 1e15067 PUD 1e17067 PMD 0 Oops: 0000 [#1] PREEMPT SMP [<ffffffffa063271d>] ? kvm_vcpu_reload_apic_access_page+0x5d/0x70 [kvm] [<ffffffffa013b6db>] vmx_vcpu_reset+0x21b/0x470 [kvm_intel] [<ffffffffa0658816>] ? kvm_pmu_reset+0x76/0xb0 [kvm] [<ffffffffa064032a>] kvm_vcpu_reset+0x15a/0x1b0 [kvm] [<ffffffffa06403ac>] kvm_arch_vcpu_setup+0x2c/0x50 [kvm] [<ffffffffa062e540>] kvm_vm_ioctl+0x200/0x780 [kvm] [<ffffffff81212170>] do_vfs_ioctl+0x2d0/0x4b0 [<ffffffff8108bd99>] ? __mmdrop+0x69/0xb0 [<ffffffff812123d1>] SyS_ioctl+0x81/0xa0 [<ffffffff8112a6f6>] ? __audit_syscall_exit+0x1f6/0x2a0 [<ffffffff817229e9>] system_call_fastpath+0x16/0x1b Code: c6 78 ce a3 81 4c 89 e7 e8 d9 80 ff ff 0f 0b 4c 89 e7 e8 8f f6 ff ff e9 fa fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 <48> f7 07 00 c0 00 00 55 48 89 e5 75 1e 8b 47 1c 85 c0 74 27 f0 RIP [<ffffffff81193045>] put_page+0x5/0x50 when not using the in-kernel irqchip ("-machine kernel_irqchip=off" with QEMU). The fix is to make the same check in kvm_vcpu_reload_apic_access_page that we already have in vmx.c's vm_need_virtualize_apic_accesses(). Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Jan Kiszka <jan.kiszka@siemens.com> Fixes: 4256f43f9fab91e1c17b5846a240cf4b66a768a8 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-02 11:53:24 +00:00
if (!irqchip_in_kernel(vcpu->kvm))
return;
if (!kvm_x86_ops->set_apic_access_page_addr)
return;
page = gfn_to_page(vcpu->kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
kvm: fix crash in kvm_vcpu_reload_apic_access_page memslot->userfault_addr is set by the kernel with a mmap executed from the kernel but the userland can still munmap it and lead to the below oops after memslot->userfault_addr points to a host virtual address that has no vma or mapping. [ 327.538306] BUG: unable to handle kernel paging request at fffffffffffffffe [ 327.538407] IP: [<ffffffff811a7b55>] put_page+0x5/0x50 [ 327.538474] PGD 1a01067 PUD 1a03067 PMD 0 [ 327.538529] Oops: 0000 [#1] SMP [ 327.538574] Modules linked in: macvtap macvlan xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT iptable_filter ip_tables tun bridge stp llc rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache xprtrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp scsi_tgt ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ipmi_devintf iTCO_wdt iTCO_vendor_support intel_powerclamp coretemp dcdbas intel_rapl kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd pcspkr sb_edac edac_core ipmi_si ipmi_msghandler acpi_pad wmi acpi_power_meter lpc_ich mfd_core mei_me [ 327.539488] mei shpchp nfsd auth_rpcgss nfs_acl lockd grace sunrpc mlx4_ib ib_sa ib_mad ib_core mlx4_en vxlan ib_addr ip_tunnel xfs libcrc32c sd_mod crc_t10dif crct10dif_common crc32c_intel mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit drm_kms_helper ttm drm ahci i2c_core libahci mlx4_core libata tg3 ptp pps_core megaraid_sas ntb dm_mirror dm_region_hash dm_log dm_mod [ 327.539956] CPU: 3 PID: 3161 Comm: qemu-kvm Not tainted 3.10.0-240.el7.userfault19.4ca4011.x86_64.debug #1 [ 327.540045] Hardware name: Dell Inc. PowerEdge R420/0CN7CM, BIOS 2.1.2 01/20/2014 [ 327.540115] task: ffff8803280ccf00 ti: ffff880317c58000 task.ti: ffff880317c58000 [ 327.540184] RIP: 0010:[<ffffffff811a7b55>] [<ffffffff811a7b55>] put_page+0x5/0x50 [ 327.540261] RSP: 0018:ffff880317c5bcf8 EFLAGS: 00010246 [ 327.540313] RAX: 00057ffffffff000 RBX: ffff880616a20000 RCX: 0000000000000000 [ 327.540379] RDX: 0000000000002014 RSI: 00057ffffffff000 RDI: fffffffffffffffe [ 327.540445] RBP: ffff880317c5bd10 R08: 0000000000000103 R09: 0000000000000000 [ 327.540511] R10: 0000000000000000 R11: 0000000000000000 R12: fffffffffffffffe [ 327.540576] R13: 0000000000000000 R14: ffff880317c5bd70 R15: ffff880317c5bd50 [ 327.540643] FS: 00007fd230b7f700(0000) GS:ffff880630800000(0000) knlGS:0000000000000000 [ 327.540717] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 327.540771] CR2: fffffffffffffffe CR3: 000000062a2c3000 CR4: 00000000000427e0 [ 327.540837] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 327.540904] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 327.540974] Stack: [ 327.541008] ffffffffa05d6d0c ffff880616a20000 0000000000000000 ffff880317c5bdc0 [ 327.541093] ffffffffa05ddaa2 0000000000000000 00000000002191bf 00000042f3feab2d [ 327.541177] 00000042f3feab2d 0000000000000002 0000000000000001 0321000000000000 [ 327.541261] Call Trace: [ 327.541321] [<ffffffffa05d6d0c>] ? kvm_vcpu_reload_apic_access_page+0x6c/0x80 [kvm] [ 327.543615] [<ffffffffa05ddaa2>] vcpu_enter_guest+0x3f2/0x10f0 [kvm] [ 327.545918] [<ffffffffa05e2f10>] kvm_arch_vcpu_ioctl_run+0x2b0/0x5a0 [kvm] [ 327.548211] [<ffffffffa05e2d02>] ? kvm_arch_vcpu_ioctl_run+0xa2/0x5a0 [kvm] [ 327.550500] [<ffffffffa05ca845>] kvm_vcpu_ioctl+0x2b5/0x680 [kvm] [ 327.552768] [<ffffffff810b8d12>] ? creds_are_invalid.part.1+0x12/0x50 [ 327.555069] [<ffffffff810b8d71>] ? creds_are_invalid+0x21/0x30 [ 327.557373] [<ffffffff812d6066>] ? inode_has_perm.isra.49.constprop.65+0x26/0x80 [ 327.559663] [<ffffffff8122d985>] do_vfs_ioctl+0x305/0x530 [ 327.561917] [<ffffffff8122dc51>] SyS_ioctl+0xa1/0xc0 [ 327.564185] [<ffffffff816de829>] system_call_fastpath+0x16/0x1b [ 327.566480] Code: 0b 31 f6 4c 89 e7 e8 4b 7f ff ff 0f 0b e8 24 fd ff ff e9 a9 fd ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 <48> f7 07 00 c0 00 00 55 48 89 e5 75 2a 8b 47 1c 85 c0 74 1e f0 Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-08 12:32:56 +00:00
if (is_error_page(page))
return;
kvm_x86_ops->set_apic_access_page_addr(vcpu, page_to_phys(page));
/*
* Do not pin apic access page in memory, the MMU notifier
* will call us again if it is migrated or swapped out.
*/
put_page(page);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page);
void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
unsigned long address)
{
/*
* The physical address of apic access page is stored in the VMCS.
* Update it when it becomes invalid.
*/
if (address == gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT))
kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
}
/*
* Returns 1 to let vcpu_run() continue the guest execution loop without
* exiting to the userspace. Otherwise, the value will be returned to the
* userspace.
*/
static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
{
int r;
bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
vcpu->run->request_interrupt_window;
bool req_immediate_exit = false;
if (vcpu->requests) {
if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu))
kvm_mmu_unload(vcpu);
if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu))
__kvm_migrate_timers(vcpu);
if (kvm_check_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu))
kvm_gen_update_masterclock(vcpu->kvm);
if (kvm_check_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu))
kvm_gen_kvmclock_update(vcpu);
if (kvm_check_request(KVM_REQ_CLOCK_UPDATE, vcpu)) {
r = kvm_guest_time_update(vcpu);
if (unlikely(r))
goto out;
}
if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu))
kvm_mmu_sync_roots(vcpu);
if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu))
kvm_vcpu_flush_tlb(vcpu);
if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) {
vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS;
r = 0;
goto out;
}
if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) {
vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
r = 0;
goto out;
}
if (kvm_check_request(KVM_REQ_DEACTIVATE_FPU, vcpu)) {
vcpu->fpu_active = 0;
kvm_x86_ops->fpu_deactivate(vcpu);
}
if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) {
/* Page is swapped out. Do synthetic halt */
vcpu->arch.apf.halted = true;
r = 1;
goto out;
}
if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu))
record_steal_time(vcpu);
if (kvm_check_request(KVM_REQ_SMI, vcpu))
process_smi(vcpu);
if (kvm_check_request(KVM_REQ_NMI, vcpu))
process_nmi(vcpu);
if (kvm_check_request(KVM_REQ_PMU, vcpu))
kvm_pmu_handle_event(vcpu);
if (kvm_check_request(KVM_REQ_PMI, vcpu))
kvm_pmu_deliver_pmi(vcpu);
if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu))
vcpu_scan_ioapic(vcpu);
if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu))
kvm_vcpu_reload_apic_access_page(vcpu);
if (kvm_check_request(KVM_REQ_HV_CRASH, vcpu)) {
vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
vcpu->run->system_event.type = KVM_SYSTEM_EVENT_CRASH;
r = 0;
goto out;
}
}
if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
kvm_apic_accept_events(vcpu);
if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
r = 1;
goto out;
}
if (inject_pending_event(vcpu, req_int_win) != 0)
req_immediate_exit = true;
/* enable NMI/IRQ window open exits if needed */
else if (vcpu->arch.nmi_pending)
kvm_x86_ops->enable_nmi_window(vcpu);
else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win)
kvm_x86_ops->enable_irq_window(vcpu);
if (kvm_lapic_enabled(vcpu)) {
/*
* Update architecture specific hints for APIC
* virtual interrupt delivery.
*/
if (kvm_x86_ops->hwapic_irr_update)
kvm_x86_ops->hwapic_irr_update(vcpu,
kvm_lapic_find_highest_irr(vcpu));
update_cr8_intercept(vcpu);
kvm_lapic_sync_to_vapic(vcpu);
}
}
r = kvm_mmu_reload(vcpu);
if (unlikely(r)) {
goto cancel_injection;
}
preempt_disable();
kvm_x86_ops->prepare_guest_switch(vcpu);
if (vcpu->fpu_active)
kvm_load_guest_fpu(vcpu);
kvm_load_guest_xcr0(vcpu);
vcpu->mode = IN_GUEST_MODE;
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
/* We should set ->mode before check ->requests,
* see the comment in make_all_cpus_request.
*/
smp_mb__after_srcu_read_unlock();
local_irq_disable();
if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests
|| need_resched() || signal_pending(current)) {
vcpu->mode = OUTSIDE_GUEST_MODE;
smp_wmb();
local_irq_enable();
preempt_enable();
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
r = 1;
goto cancel_injection;
}
KVM: nVMX: Add KVM_REQ_IMMEDIATE_EXIT This patch adds a new vcpu->requests bit, KVM_REQ_IMMEDIATE_EXIT. This bit requests that when next entering the guest, we should run it only for as little as possible, and exit again. We use this new option in nested VMX: When L1 launches L2, but L0 wishes L1 to continue running so it can inject an event to it, we unfortunately cannot just pretend to have run L2 for a little while - We must really launch L2, otherwise certain one-off vmcs12 parameters (namely, L1 injection into L2) will be lost. So the existing code runs L2 in this case. But L2 could potentially run for a long time until it exits, and the injection into L1 will be delayed. The new KVM_REQ_IMMEDIATE_EXIT allows us to request that L2 will be entered, as necessary, but will exit as soon as possible after entry. Our implementation of this request uses smp_send_reschedule() to send a self-IPI, with interrupts disabled. The interrupts remain disabled until the guest is entered, and then, after the entry is complete (often including processing an injection and jumping to the relevant handler), the physical interrupt is noticed and causes an exit. On recent Intel processors, we could have achieved the same goal by using MTF instead of a self-IPI. Another technique worth considering in the future is to use VM_EXIT_ACK_INTR_ON_EXIT and a highest-priority vector IPI - to slightly improve performance by avoiding the useless interrupt handler which ends up being called when smp_send_reschedule() is used. Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-09-22 10:52:56 +00:00
if (req_immediate_exit)
smp_send_reschedule(vcpu->cpu);
__kvm_guest_enter();
if (unlikely(vcpu->arch.switch_db_regs)) {
set_debugreg(0, 7);
set_debugreg(vcpu->arch.eff_db[0], 0);
set_debugreg(vcpu->arch.eff_db[1], 1);
set_debugreg(vcpu->arch.eff_db[2], 2);
set_debugreg(vcpu->arch.eff_db[3], 3);
set_debugreg(vcpu->arch.dr6, 6);
vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD;
}
trace_kvm_entry(vcpu->vcpu_id);
wait_lapic_expire(vcpu);
kvm_x86_ops->run(vcpu);
/*
* Do this here before restoring debug registers on the host. And
* since we do this before handling the vmexit, a DR access vmexit
* can (a) read the correct value of the debug registers, (b) set
* KVM_DEBUGREG_WONT_EXIT again.
*/
if (unlikely(vcpu->arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)) {
int i;
WARN_ON(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP);
kvm_x86_ops->sync_dirty_debug_regs(vcpu);
for (i = 0; i < KVM_NR_DB_REGS; i++)
vcpu->arch.eff_db[i] = vcpu->arch.db[i];
}
hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
2009-09-09 17:22:48 +00:00
/*
* If the guest has used debug registers, at least dr7
* will be disabled while returning to the host.
* If we don't have active breakpoints in the host, we don't
* care about the messed up debug address registers. But if
* we have some of them active, restore the old state.
*/
if (hw_breakpoint_active())
hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
2009-09-09 17:22:48 +00:00
hw_breakpoint_restore();
vcpu->arch.last_guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu,
rdtsc());
vcpu->mode = OUTSIDE_GUEST_MODE;
smp_wmb();
/* Interrupt is enabled by handle_external_intr() */
kvm_x86_ops->handle_external_intr(vcpu);
++vcpu->stat.exits;
/*
* We must have an instruction between local_irq_enable() and
* kvm_guest_exit(), so the timer interrupt isn't delayed by
* the interrupt shadow. The stat.exits increment will do nicely.
* But we need to prevent reordering, hence this barrier():
*/
barrier();
kvm_guest_exit();
preempt_enable();
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
/*
* Profile KVM exit RIPs:
*/
if (unlikely(prof_on == KVM_PROFILING)) {
unsigned long rip = kvm_rip_read(vcpu);
profile_hit(KVM_PROFILING, (void *)rip);
}
2012-02-03 17:43:50 +00:00
if (unlikely(vcpu->arch.tsc_always_catchup))
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
if (vcpu->arch.apic_attention)
kvm_lapic_sync_from_vapic(vcpu);
r = kvm_x86_ops->handle_exit(vcpu);
return r;
cancel_injection:
kvm_x86_ops->cancel_injection(vcpu);
if (unlikely(vcpu->arch.apic_attention))
kvm_lapic_sync_from_vapic(vcpu);
out:
return r;
}
static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
{
if (!kvm_arch_vcpu_runnable(vcpu)) {
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
kvm_vcpu_block(vcpu);
vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
if (!kvm_check_request(KVM_REQ_UNHALT, vcpu))
return 1;
}
kvm_apic_accept_events(vcpu);
switch(vcpu->arch.mp_state) {
case KVM_MP_STATE_HALTED:
vcpu->arch.pv.pv_unhalted = false;
vcpu->arch.mp_state =
KVM_MP_STATE_RUNNABLE;
case KVM_MP_STATE_RUNNABLE:
vcpu->arch.apf.halted = false;
break;
case KVM_MP_STATE_INIT_RECEIVED:
break;
default:
return -EINTR;
break;
}
return 1;
}
static int vcpu_run(struct kvm_vcpu *vcpu)
{
int r;
struct kvm *kvm = vcpu->kvm;
vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
for (;;) {
if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
!vcpu->arch.apf.halted)
r = vcpu_enter_guest(vcpu);
else
r = vcpu_block(kvm, vcpu);
if (r <= 0)
break;
clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
if (kvm_cpu_has_pending_timer(vcpu))
kvm_inject_pending_timer_irqs(vcpu);
if (dm_request_for_irq_injection(vcpu)) {
r = -EINTR;
vcpu->run->exit_reason = KVM_EXIT_INTR;
++vcpu->stat.request_irq_exits;
break;
}
kvm_check_async_pf_completion(vcpu);
if (signal_pending(current)) {
r = -EINTR;
vcpu->run->exit_reason = KVM_EXIT_INTR;
++vcpu->stat.signal_exits;
break;
}
if (need_resched()) {
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
cond_resched();
vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
}
}
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
return r;
}
static inline int complete_emulated_io(struct kvm_vcpu *vcpu)
{
int r;
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
r = emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (r != EMULATE_DONE)
return 0;
return 1;
}
static int complete_emulated_pio(struct kvm_vcpu *vcpu)
{
BUG_ON(!vcpu->arch.pio.count);
return complete_emulated_io(vcpu);
}
/*
* Implements the following, as a state machine:
*
* read:
* for each fragment
* for each mmio piece in the fragment
* write gpa, len
* exit
* copy data
* execute insn
*
* write:
* for each fragment
* for each mmio piece in the fragment
* write gpa, len
* copy data
* exit
*/
static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
struct kvm_mmio_fragment *frag;
unsigned len;
BUG_ON(!vcpu->mmio_needed);
/* Complete previous fragment */
frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment];
len = min(8u, frag->len);
if (!vcpu->mmio_is_write)
memcpy(frag->data, run->mmio.data, len);
if (frag->len <= 8) {
/* Switch to the next fragment. */
frag++;
vcpu->mmio_cur_fragment++;
} else {
/* Go forward to the next mmio piece. */
frag->data += len;
frag->gpa += len;
frag->len -= len;
}
if (vcpu->mmio_cur_fragment >= vcpu->mmio_nr_fragments) {
vcpu->mmio_needed = 0;
/* FIXME: return into emulator if single-stepping. */
if (vcpu->mmio_is_write)
return 1;
vcpu->mmio_read_completed = 1;
return complete_emulated_io(vcpu);
}
run->exit_reason = KVM_EXIT_MMIO;
run->mmio.phys_addr = frag->gpa;
if (vcpu->mmio_is_write)
memcpy(run->mmio.data, frag->data, min(8u, frag->len));
run->mmio.len = min(8u, frag->len);
run->mmio.is_write = vcpu->mmio_is_write;
vcpu->arch.complete_userspace_io = complete_emulated_mmio;
return 0;
}
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
struct fpu *fpu = &current->thread.fpu;
int r;
sigset_t sigsaved;
fpu__activate_curr(fpu);
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
kvm_vcpu_block(vcpu);
kvm_apic_accept_events(vcpu);
clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
r = -EAGAIN;
goto out;
}
/* re-sync apic's tpr */
if (!irqchip_in_kernel(vcpu->kvm)) {
if (kvm_set_cr8(vcpu, kvm_run->cr8) != 0) {
r = -EINVAL;
goto out;
}
}
if (unlikely(vcpu->arch.complete_userspace_io)) {
int (*cui)(struct kvm_vcpu *) = vcpu->arch.complete_userspace_io;
vcpu->arch.complete_userspace_io = NULL;
r = cui(vcpu);
if (r <= 0)
goto out;
} else
WARN_ON(vcpu->arch.pio.count || vcpu->mmio_needed);
r = vcpu_run(vcpu);
out:
post_kvm_run_save(vcpu);
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
return r;
}
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
if (vcpu->arch.emulate_regs_need_sync_to_vcpu) {
/*
* We are here if userspace calls get_regs() in the middle of
* instruction emulation. Registers state needs to be copied
* back from emulation context to vcpu. Userspace shouldn't do
* that usually, but some bad designed PV devices (vmware
* backdoor interface) need this to work
*/
emulator_writeback_register_cache(&vcpu->arch.emulate_ctxt);
vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
}
regs->rax = kvm_register_read(vcpu, VCPU_REGS_RAX);
regs->rbx = kvm_register_read(vcpu, VCPU_REGS_RBX);
regs->rcx = kvm_register_read(vcpu, VCPU_REGS_RCX);
regs->rdx = kvm_register_read(vcpu, VCPU_REGS_RDX);
regs->rsi = kvm_register_read(vcpu, VCPU_REGS_RSI);
regs->rdi = kvm_register_read(vcpu, VCPU_REGS_RDI);
regs->rsp = kvm_register_read(vcpu, VCPU_REGS_RSP);
regs->rbp = kvm_register_read(vcpu, VCPU_REGS_RBP);
#ifdef CONFIG_X86_64
regs->r8 = kvm_register_read(vcpu, VCPU_REGS_R8);
regs->r9 = kvm_register_read(vcpu, VCPU_REGS_R9);
regs->r10 = kvm_register_read(vcpu, VCPU_REGS_R10);
regs->r11 = kvm_register_read(vcpu, VCPU_REGS_R11);
regs->r12 = kvm_register_read(vcpu, VCPU_REGS_R12);
regs->r13 = kvm_register_read(vcpu, VCPU_REGS_R13);
regs->r14 = kvm_register_read(vcpu, VCPU_REGS_R14);
regs->r15 = kvm_register_read(vcpu, VCPU_REGS_R15);
#endif
regs->rip = kvm_rip_read(vcpu);
regs->rflags = kvm_get_rflags(vcpu);
return 0;
}
int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
vcpu->arch.emulate_regs_need_sync_from_vcpu = true;
vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
kvm_register_write(vcpu, VCPU_REGS_RAX, regs->rax);
kvm_register_write(vcpu, VCPU_REGS_RBX, regs->rbx);
kvm_register_write(vcpu, VCPU_REGS_RCX, regs->rcx);
kvm_register_write(vcpu, VCPU_REGS_RDX, regs->rdx);
kvm_register_write(vcpu, VCPU_REGS_RSI, regs->rsi);
kvm_register_write(vcpu, VCPU_REGS_RDI, regs->rdi);
kvm_register_write(vcpu, VCPU_REGS_RSP, regs->rsp);
kvm_register_write(vcpu, VCPU_REGS_RBP, regs->rbp);
#ifdef CONFIG_X86_64
kvm_register_write(vcpu, VCPU_REGS_R8, regs->r8);
kvm_register_write(vcpu, VCPU_REGS_R9, regs->r9);
kvm_register_write(vcpu, VCPU_REGS_R10, regs->r10);
kvm_register_write(vcpu, VCPU_REGS_R11, regs->r11);
kvm_register_write(vcpu, VCPU_REGS_R12, regs->r12);
kvm_register_write(vcpu, VCPU_REGS_R13, regs->r13);
kvm_register_write(vcpu, VCPU_REGS_R14, regs->r14);
kvm_register_write(vcpu, VCPU_REGS_R15, regs->r15);
#endif
kvm_rip_write(vcpu, regs->rip);
kvm_set_rflags(vcpu, regs->rflags);
vcpu->arch.exception.pending = false;
kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
{
struct kvm_segment cs;
kvm_get_segment(vcpu, &cs, VCPU_SREG_CS);
*db = cs.db;
*l = cs.l;
}
EXPORT_SYMBOL_GPL(kvm_get_cs_db_l_bits);
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct desc_ptr dt;
kvm_get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
kvm_get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
kvm_get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
kvm_get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
kvm_get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
kvm_get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
kvm_get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
kvm_get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
kvm_x86_ops->get_idt(vcpu, &dt);
sregs->idt.limit = dt.size;
sregs->idt.base = dt.address;
kvm_x86_ops->get_gdt(vcpu, &dt);
sregs->gdt.limit = dt.size;
sregs->gdt.base = dt.address;
sregs->cr0 = kvm_read_cr0(vcpu);
sregs->cr2 = vcpu->arch.cr2;
sregs->cr3 = kvm_read_cr3(vcpu);
sregs->cr4 = kvm_read_cr4(vcpu);
sregs->cr8 = kvm_get_cr8(vcpu);
sregs->efer = vcpu->arch.efer;
sregs->apic_base = kvm_get_apic_base(vcpu);
memset(sregs->interrupt_bitmap, 0, sizeof sregs->interrupt_bitmap);
if (vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft)
set_bit(vcpu->arch.interrupt.nr,
(unsigned long *)sregs->interrupt_bitmap);
return 0;
}
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
kvm_apic_accept_events(vcpu);
if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED &&
vcpu->arch.pv.pv_unhalted)
mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
else
mp_state->mp_state = vcpu->arch.mp_state;
return 0;
}
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
if (!kvm_vcpu_has_lapic(vcpu) &&
mp_state->mp_state != KVM_MP_STATE_RUNNABLE)
return -EINVAL;
if (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED) {
vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
set_bit(KVM_APIC_SIPI, &vcpu->arch.apic->pending_events);
} else
vcpu->arch.mp_state = mp_state->mp_state;
kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
int reason, bool has_error_code, u32 error_code)
{
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
int ret;
init_emulate_ctxt(vcpu);
ret = emulator_task_switch(ctxt, tss_selector, idt_index, reason,
has_error_code, error_code);
if (ret)
return EMULATE_FAIL;
kvm_rip_write(vcpu, ctxt->eip);
kvm_set_rflags(vcpu, ctxt->eflags);
kvm_make_request(KVM_REQ_EVENT, vcpu);
return EMULATE_DONE;
}
EXPORT_SYMBOL_GPL(kvm_task_switch);
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct msr_data apic_base_msr;
int mmu_reset_needed = 0;
int pending_vec, max_bits, idx;
struct desc_ptr dt;
KVM: x86: invalid opcode oops on SET_SREGS with OSXSAVE bit set (CVE-2012-4461) On hosts without the XSAVE support unprivileged local user can trigger oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN ioctl. invalid opcode: 0000 [#2] SMP Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables ... Pid: 24935, comm: zoog_kvm_monito Tainted: G D 3.2.0-3-686-pae EIP: 0060:[<f8b9550c>] EFLAGS: 00210246 CPU: 0 EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000 ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0 task.ti=d7c62000) Stack: 00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000 ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0 c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80 Call Trace: [<f8b940a9>] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm] ... [<c12bfb44>] ? syscall_call+0x7/0xb Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74 1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 <0f> 01 d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89 EIP: [<f8b9550c>] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP 0068:d7c63e70 QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID and then sets them later. So guest's X86_FEATURE_XSAVE should be masked out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with X86_FEATURE_XSAVE even on hosts that do not support it, might be susceptible to this attack from inside the guest as well. Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support. Signed-off-by: Petr Matousek <pmatouse@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-06 18:24:07 +00:00
if (!guest_cpuid_has_xsave(vcpu) && (sregs->cr4 & X86_CR4_OSXSAVE))
return -EINVAL;
dt.size = sregs->idt.limit;
dt.address = sregs->idt.base;
kvm_x86_ops->set_idt(vcpu, &dt);
dt.size = sregs->gdt.limit;
dt.address = sregs->gdt.base;
kvm_x86_ops->set_gdt(vcpu, &dt);
vcpu->arch.cr2 = sregs->cr2;
mmu_reset_needed |= kvm_read_cr3(vcpu) != sregs->cr3;
vcpu->arch.cr3 = sregs->cr3;
__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
kvm_set_cr8(vcpu, sregs->cr8);
mmu_reset_needed |= vcpu->arch.efer != sregs->efer;
kvm_x86_ops->set_efer(vcpu, sregs->efer);
apic_base_msr.data = sregs->apic_base;
apic_base_msr.host_initiated = true;
kvm_set_apic_base(vcpu, &apic_base_msr);
mmu_reset_needed |= kvm_read_cr0(vcpu) != sregs->cr0;
kvm_x86_ops->set_cr0(vcpu, sregs->cr0);
vcpu->arch.cr0 = sregs->cr0;
mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
if (sregs->cr4 & X86_CR4_OSXSAVE)
kvm_update_cpuid(vcpu);
idx = srcu_read_lock(&vcpu->kvm->srcu);
if (!is_long_mode(vcpu) && is_pae(vcpu)) {
load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
mmu_reset_needed = 1;
}
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (mmu_reset_needed)
kvm_mmu_reset_context(vcpu);
max_bits = KVM_NR_INTERRUPTS;
pending_vec = find_first_bit(
(const unsigned long *)sregs->interrupt_bitmap, max_bits);
if (pending_vec < max_bits) {
kvm_queue_interrupt(vcpu, pending_vec, false);
pr_debug("Set back pending irq %d\n", pending_vec);
}
kvm_set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
kvm_set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
kvm_set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
kvm_set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
kvm_set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
kvm_set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
kvm_set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
kvm_set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
update_cr8_intercept(vcpu);
/* Older userspace won't unhalt the vcpu on reset. */
if (kvm_vcpu_is_bsp(vcpu) && kvm_rip_read(vcpu) == 0xfff0 &&
sregs->cs.selector == 0xf000 && sregs->cs.base == 0xffff0000 &&
!is_protmode(vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg)
{
unsigned long rflags;
int i, r;
if (dbg->control & (KVM_GUESTDBG_INJECT_DB | KVM_GUESTDBG_INJECT_BP)) {
r = -EBUSY;
if (vcpu->arch.exception.pending)
goto out;
if (dbg->control & KVM_GUESTDBG_INJECT_DB)
kvm_queue_exception(vcpu, DB_VECTOR);
else
kvm_queue_exception(vcpu, BP_VECTOR);
}
/*
* Read rflags as long as potentially injected trace flags are still
* filtered out.
*/
rflags = kvm_get_rflags(vcpu);
vcpu->guest_debug = dbg->control;
if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
vcpu->guest_debug = 0;
if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
for (i = 0; i < KVM_NR_DB_REGS; ++i)
vcpu->arch.eff_db[i] = dbg->arch.debugreg[i];
vcpu->arch.guest_debug_dr7 = dbg->arch.debugreg[7];
} else {
for (i = 0; i < KVM_NR_DB_REGS; i++)
vcpu->arch.eff_db[i] = vcpu->arch.db[i];
}
kvm_update_dr7(vcpu);
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
vcpu->arch.singlestep_rip = kvm_rip_read(vcpu) +
get_segment_base(vcpu, VCPU_SREG_CS);
/*
* Trigger an rflags update that will inject or remove the trace
* flags.
*/
kvm_set_rflags(vcpu, rflags);
kvm_x86_ops->update_db_bp_intercept(vcpu);
r = 0;
out:
return r;
}
/*
* Translate a guest virtual address to a guest physical address.
*/
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr)
{
unsigned long vaddr = tr->linear_address;
gpa_t gpa;
int idx;
idx = srcu_read_lock(&vcpu->kvm->srcu);
gpa = kvm_mmu_gva_to_gpa_system(vcpu, vaddr, NULL);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
tr->physical_address = gpa;
tr->valid = gpa != UNMAPPED_GVA;
tr->writeable = 1;
tr->usermode = 0;
return 0;
}
int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
struct fxregs_state *fxsave =
x86/fpu: Simplify FPU handling by embedding the fpstate in task_struct (again) So 6 years ago we made the FPU fpstate dynamically allocated: aa283f49276e ("x86, fpu: lazy allocation of FPU area - v5") 61c4628b5386 ("x86, fpu: split FPU state from task struct - v5") In hindsight this was a mistake: - it complicated context allocation failure handling, such as: /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(fpstate_alloc_init(fpu))) force_sig(SIGKILL, tsk); - it caused us to enable irqs in fpu__restore(): local_irq_enable(); /* * does a slab alloc which can sleep */ if (fpstate_alloc_init(fpu)) { /* * ran out of memory! */ do_group_exit(SIGKILL); return; } local_irq_disable(); - it (slightly) slowed down task creation/destruction by adding slab allocation/free pattens. - it made access to context contents (slightly) slower by adding one more pointer dereference. The motivation for the dynamic allocation was two-fold: - reduce memory consumption by non-FPU tasks - allocate and handle only the necessary amount of context for various XSAVE processors that have varying hardware frame sizes. These days, with glibc using SSE memcpy by default and GCC optimizing for SSE/AVX by default, the scope of FPU using apps on an x86 system is much larger than it was 6 years ago. For example on a freshly installed Fedora 21 desktop system, with a recent kernel, all non-kthread tasks have used the FPU shortly after bootup. Also, even modern embedded x86 CPUs try to support the latest vector instruction set - so they'll too often use the larger xstate frame sizes. So remove the dynamic allocation complication by embedding the FPU fpstate in task_struct again. This should make the FPU a lot more accessible to all sorts of atomic contexts. We could still optimize for the xstate frame size in the future, by moving the state structure to the last element of task_struct, and allocating only a part of that. This change is kept minimal by still keeping the ctx_alloc()/free() routines (that now do nothing substantial) - we'll remove them in the following patches. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-27 02:19:39 +00:00
&vcpu->arch.guest_fpu.state.fxsave;
memcpy(fpu->fpr, fxsave->st_space, 128);
fpu->fcw = fxsave->cwd;
fpu->fsw = fxsave->swd;
fpu->ftwx = fxsave->twd;
fpu->last_opcode = fxsave->fop;
fpu->last_ip = fxsave->rip;
fpu->last_dp = fxsave->rdp;
memcpy(fpu->xmm, fxsave->xmm_space, sizeof fxsave->xmm_space);
return 0;
}
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
struct fxregs_state *fxsave =
x86/fpu: Simplify FPU handling by embedding the fpstate in task_struct (again) So 6 years ago we made the FPU fpstate dynamically allocated: aa283f49276e ("x86, fpu: lazy allocation of FPU area - v5") 61c4628b5386 ("x86, fpu: split FPU state from task struct - v5") In hindsight this was a mistake: - it complicated context allocation failure handling, such as: /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(fpstate_alloc_init(fpu))) force_sig(SIGKILL, tsk); - it caused us to enable irqs in fpu__restore(): local_irq_enable(); /* * does a slab alloc which can sleep */ if (fpstate_alloc_init(fpu)) { /* * ran out of memory! */ do_group_exit(SIGKILL); return; } local_irq_disable(); - it (slightly) slowed down task creation/destruction by adding slab allocation/free pattens. - it made access to context contents (slightly) slower by adding one more pointer dereference. The motivation for the dynamic allocation was two-fold: - reduce memory consumption by non-FPU tasks - allocate and handle only the necessary amount of context for various XSAVE processors that have varying hardware frame sizes. These days, with glibc using SSE memcpy by default and GCC optimizing for SSE/AVX by default, the scope of FPU using apps on an x86 system is much larger than it was 6 years ago. For example on a freshly installed Fedora 21 desktop system, with a recent kernel, all non-kthread tasks have used the FPU shortly after bootup. Also, even modern embedded x86 CPUs try to support the latest vector instruction set - so they'll too often use the larger xstate frame sizes. So remove the dynamic allocation complication by embedding the FPU fpstate in task_struct again. This should make the FPU a lot more accessible to all sorts of atomic contexts. We could still optimize for the xstate frame size in the future, by moving the state structure to the last element of task_struct, and allocating only a part of that. This change is kept minimal by still keeping the ctx_alloc()/free() routines (that now do nothing substantial) - we'll remove them in the following patches. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-27 02:19:39 +00:00
&vcpu->arch.guest_fpu.state.fxsave;
memcpy(fxsave->st_space, fpu->fpr, 128);
fxsave->cwd = fpu->fcw;
fxsave->swd = fpu->fsw;
fxsave->twd = fpu->ftwx;
fxsave->fop = fpu->last_opcode;
fxsave->rip = fpu->last_ip;
fxsave->rdp = fpu->last_dp;
memcpy(fxsave->xmm_space, fpu->xmm, sizeof fxsave->xmm_space);
return 0;
}
static void fx_init(struct kvm_vcpu *vcpu)
{
fpstate_init(&vcpu->arch.guest_fpu.state);
if (cpu_has_xsaves)
x86/fpu: Simplify FPU handling by embedding the fpstate in task_struct (again) So 6 years ago we made the FPU fpstate dynamically allocated: aa283f49276e ("x86, fpu: lazy allocation of FPU area - v5") 61c4628b5386 ("x86, fpu: split FPU state from task struct - v5") In hindsight this was a mistake: - it complicated context allocation failure handling, such as: /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(fpstate_alloc_init(fpu))) force_sig(SIGKILL, tsk); - it caused us to enable irqs in fpu__restore(): local_irq_enable(); /* * does a slab alloc which can sleep */ if (fpstate_alloc_init(fpu)) { /* * ran out of memory! */ do_group_exit(SIGKILL); return; } local_irq_disable(); - it (slightly) slowed down task creation/destruction by adding slab allocation/free pattens. - it made access to context contents (slightly) slower by adding one more pointer dereference. The motivation for the dynamic allocation was two-fold: - reduce memory consumption by non-FPU tasks - allocate and handle only the necessary amount of context for various XSAVE processors that have varying hardware frame sizes. These days, with glibc using SSE memcpy by default and GCC optimizing for SSE/AVX by default, the scope of FPU using apps on an x86 system is much larger than it was 6 years ago. For example on a freshly installed Fedora 21 desktop system, with a recent kernel, all non-kthread tasks have used the FPU shortly after bootup. Also, even modern embedded x86 CPUs try to support the latest vector instruction set - so they'll too often use the larger xstate frame sizes. So remove the dynamic allocation complication by embedding the FPU fpstate in task_struct again. This should make the FPU a lot more accessible to all sorts of atomic contexts. We could still optimize for the xstate frame size in the future, by moving the state structure to the last element of task_struct, and allocating only a part of that. This change is kept minimal by still keeping the ctx_alloc()/free() routines (that now do nothing substantial) - we'll remove them in the following patches. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-27 02:19:39 +00:00
vcpu->arch.guest_fpu.state.xsave.header.xcomp_bv =
host_xcr0 | XSTATE_COMPACTION_ENABLED;
/*
* Ensure guest xcr0 is valid for loading
*/
vcpu->arch.xcr0 = XSTATE_FP;
vcpu->arch.cr0 |= X86_CR0_ET;
}
void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_fpu_loaded)
return;
/*
* Restore all possible states in the guest,
* and assume host would use all available bits.
* Guest xcr0 would be loaded later.
*/
kvm_put_guest_xcr0(vcpu);
vcpu->guest_fpu_loaded = 1;
__kernel_fpu_begin();
__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state);
trace_kvm_fpu(1);
}
void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
{
kvm_put_guest_xcr0(vcpu);
if (!vcpu->guest_fpu_loaded) {
vcpu->fpu_counter = 0;
return;
}
vcpu->guest_fpu_loaded = 0;
x86/fpu: Rename fpu_save_init() to copy_fpregs_to_fpstate() So fpu_save_init() is a historic name that got its name when the only way the FPU state was FNSAVE, which cleared (well, destroyed) the FPU state after saving it. Nowadays the name is misleading, because ever since the introduction of FXSAVE (and more modern FPU saving instructions) the 'we need to reload the FPU state' part is only true if there's a pending FPU exception [*], which is almost never the case. So rename it to copy_fpregs_to_fpstate() to make it clear what's happening. Also add a few comments about why we cannot keep registers in certain cases. Also clean up the control flow a bit, to make it more apparent when we are dropping/keeping FP registers, and to optimize the common case (of keeping fpregs) some more. [*] Probably not true anymore, modern instructions always leave the FPU state intact, even if exceptions are pending: because pending FP exceptions are posted on the next FP instruction, not asynchronously. They were truly asynchronous back in the IRQ13 case, and we had to synchronize with them, but that code is not working anymore: we don't have IRQ13 mapped in the IDT anymore. But a cleanup patch is obviously not the place to change subtle behavior. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-27 00:53:16 +00:00
copy_fpregs_to_fpstate(&vcpu->arch.guest_fpu);
__kernel_fpu_end();
++vcpu->stat.fpu_reload;
/*
* If using eager FPU mode, or if the guest is a frequent user
* of the FPU, just leave the FPU active for next time.
* Every 255 times fpu_counter rolls over to 0; a guest that uses
* the FPU in bursts will revert to loading it on demand.
*/
if (!vcpu->arch.eager_fpu) {
if (++vcpu->fpu_counter < 5)
kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu);
}
trace_kvm_fpu(0);
}
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
kvmclock_reset(vcpu);
free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
kvm_x86_ops->vcpu_free(vcpu);
}
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
unsigned int id)
{
struct kvm_vcpu *vcpu;
if (check_tsc_unstable() && atomic_read(&kvm->online_vcpus) != 0)
printk_once(KERN_WARNING
"kvm: SMP vm created on host with unstable TSC; "
"guest TSC will not be reliable\n");
vcpu = kvm_x86_ops->vcpu_create(kvm, id);
return vcpu;
}
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
int r;
kvm_vcpu_mtrr_init(vcpu);
r = vcpu_load(vcpu);
if (r)
return r;
kvm_vcpu_reset(vcpu, false);
kvm_mmu_setup(vcpu);
vcpu_put(vcpu);
return r;
}
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
struct msr_data msr;
struct kvm *kvm = vcpu->kvm;
if (vcpu_load(vcpu))
return;
msr.data = 0x0;
msr.index = MSR_IA32_TSC;
msr.host_initiated = true;
kvm_write_tsc(vcpu, &msr);
vcpu_put(vcpu);
if (!kvmclock_periodic_sync)
return;
schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
KVMCLOCK_SYNC_PERIOD);
}
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
int r;
vcpu->arch.apf.msr_val = 0;
r = vcpu_load(vcpu);
BUG_ON(r);
kvm_mmu_unload(vcpu);
vcpu_put(vcpu);
kvm_x86_ops->vcpu_free(vcpu);
}
void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
{
vcpu->arch.hflags = 0;
atomic_set(&vcpu->arch.nmi_queued, 0);
vcpu->arch.nmi_pending = 0;
vcpu->arch.nmi_injected = false;
kvm_clear_interrupt_queue(vcpu);
kvm_clear_exception_queue(vcpu);
memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
kvm_update_dr0123(vcpu);
vcpu->arch.dr6 = DR6_INIT;
kvm_update_dr6(vcpu);
vcpu->arch.dr7 = DR7_FIXED_1;
kvm_update_dr7(vcpu);
vcpu->arch.cr2 = 0;
kvm_make_request(KVM_REQ_EVENT, vcpu);
vcpu->arch.apf.msr_val = 0;
vcpu->arch.st.msr_val = 0;
kvmclock_reset(vcpu);
kvm_clear_async_pf_completion_queue(vcpu);
kvm_async_pf_hash_reset(vcpu);
vcpu->arch.apf.halted = false;
if (!init_event) {
kvm_pmu_reset(vcpu);
vcpu->arch.smbase = 0x30000;
}
memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
vcpu->arch.regs_avail = ~0;
vcpu->arch.regs_dirty = ~0;
kvm_x86_ops->vcpu_reset(vcpu, init_event);
}
void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
{
struct kvm_segment cs;
kvm_get_segment(vcpu, &cs, VCPU_SREG_CS);
cs.selector = vector << 8;
cs.base = vector << 12;
kvm_set_segment(vcpu, &cs, VCPU_SREG_CS);
kvm_rip_write(vcpu, 0);
}
int kvm_arch_hardware_enable(void)
{
struct kvm *kvm;
struct kvm_vcpu *vcpu;
int i;
int ret;
u64 local_tsc;
u64 max_tsc = 0;
bool stable, backwards_tsc = false;
kvm_shared_msr_cpu_online();
ret = kvm_x86_ops->hardware_enable();
if (ret != 0)
return ret;
local_tsc = rdtsc();
stable = !check_tsc_unstable();
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!stable && vcpu->cpu == smp_processor_id())
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
if (stable && vcpu->arch.last_host_tsc > local_tsc) {
backwards_tsc = true;
if (vcpu->arch.last_host_tsc > max_tsc)
max_tsc = vcpu->arch.last_host_tsc;
}
}
}
/*
* Sometimes, even reliable TSCs go backwards. This happens on
* platforms that reset TSC during suspend or hibernate actions, but
* maintain synchronization. We must compensate. Fortunately, we can
* detect that condition here, which happens early in CPU bringup,
* before any KVM threads can be running. Unfortunately, we can't
* bring the TSCs fully up to date with real time, as we aren't yet far
* enough into CPU bringup that we know how much real time has actually
* elapsed; our helper function, get_kernel_ns() will be using boot
* variables that haven't been updated yet.
*
* So we simply find the maximum observed TSC above, then record the
* adjustment to TSC in each VCPU. When the VCPU later gets loaded,
* the adjustment will be applied. Note that we accumulate
* adjustments, in case multiple suspend cycles happen before some VCPU
* gets a chance to run again. In the event that no KVM threads get a
* chance to run, we will miss the entire elapsed period, as we'll have
* reset last_host_tsc, so VCPUs will not have the TSC adjusted and may
* loose cycle time. This isn't too big a deal, since the loss will be
* uniform across all VCPUs (not to mention the scenario is extremely
* unlikely). It is possible that a second hibernate recovery happens
* much faster than a first, causing the observed TSC here to be
* smaller; this would require additional padding adjustment, which is
* why we set last_host_tsc to the local tsc observed here.
*
* N.B. - this code below runs only on platforms with reliable TSC,
* as that is the only way backwards_tsc is set above. Also note
* that this runs for ALL vcpus, which is not a bug; all VCPUs should
* have the same delta_cyc adjustment applied if backwards_tsc
* is detected. Note further, this adjustment is only done once,
* as we reset last_host_tsc on all VCPUs to stop this from being
* called multiple times (one for each physical CPU bringup).
*
* Platforms with unreliable TSCs don't have to deal with this, they
* will be compensated by the logic in vcpu_load, which sets the TSC to
* catchup mode. This will catchup all VCPUs to real time, but cannot
* guarantee that they stay in perfect synchronization.
*/
if (backwards_tsc) {
u64 delta_cyc = max_tsc - local_tsc;
backwards_tsc_observed = true;
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_for_each_vcpu(i, vcpu, kvm) {
vcpu->arch.tsc_offset_adjustment += delta_cyc;
vcpu->arch.last_host_tsc = local_tsc;
kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
}
/*
* We have to disable TSC offset matching.. if you were
* booting a VM while issuing an S4 host suspend....
* you may have some problem. Solving this issue is
* left as an exercise to the reader.
*/
kvm->arch.last_tsc_nsec = 0;
kvm->arch.last_tsc_write = 0;
}
}
return 0;
}
void kvm_arch_hardware_disable(void)
{
kvm_x86_ops->hardware_disable();
drop_user_return_notifiers();
}
int kvm_arch_hardware_setup(void)
{
int r;
r = kvm_x86_ops->hardware_setup();
if (r != 0)
return r;
kvm_init_msr_list();
return 0;
}
void kvm_arch_hardware_unsetup(void)
{
kvm_x86_ops->hardware_unsetup();
}
void kvm_arch_check_processor_compat(void *rtn)
{
kvm_x86_ops->check_processor_compatibility(rtn);
}
bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_is_reset_bsp);
bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
{
return (vcpu->arch.apic_base & MSR_IA32_APICBASE_BSP) != 0;
}
bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu)
{
return irqchip_in_kernel(vcpu->kvm) == (vcpu->arch.apic != NULL);
}
struct static_key kvm_no_apic_vcpu __read_mostly;
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
struct page *page;
struct kvm *kvm;
int r;
BUG_ON(vcpu->kvm == NULL);
kvm = vcpu->kvm;
vcpu->arch.pv.pv_unhalted = false;
vcpu->arch.emulate_ctxt.ops = &emulate_ops;
if (!irqchip_in_kernel(kvm) || kvm_vcpu_is_reset_bsp(vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
else
vcpu->arch.mp_state = KVM_MP_STATE_UNINITIALIZED;
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!page) {
r = -ENOMEM;
goto fail;
}
vcpu->arch.pio_data = page_address(page);
2012-02-03 17:43:50 +00:00
kvm_set_tsc_khz(vcpu, max_tsc_khz);
r = kvm_mmu_create(vcpu);
if (r < 0)
goto fail_free_pio_data;
if (irqchip_in_kernel(kvm)) {
r = kvm_create_lapic(vcpu);
if (r < 0)
goto fail_mmu_destroy;
} else
static_key_slow_inc(&kvm_no_apic_vcpu);
vcpu->arch.mce_banks = kzalloc(KVM_MAX_MCE_BANKS * sizeof(u64) * 4,
GFP_KERNEL);
if (!vcpu->arch.mce_banks) {
r = -ENOMEM;
goto fail_free_lapic;
}
vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;
if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask, GFP_KERNEL)) {
r = -ENOMEM;
goto fail_free_mce_banks;
}
fx_init(vcpu);
KVM: x86: Emulate IA32_TSC_ADJUST MSR CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 20:42:50 +00:00
vcpu->arch.ia32_tsc_adjust_msr = 0x0;
vcpu->arch.pv_time_enabled = false;
vcpu->arch.guest_supported_xcr0 = 0;
vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;
kvm_async_pf_hash_reset(vcpu);
kvm_pmu_init(vcpu);
return 0;
fail_free_mce_banks:
kfree(vcpu->arch.mce_banks);
fail_free_lapic:
kvm_free_lapic(vcpu);
fail_mmu_destroy:
kvm_mmu_destroy(vcpu);
fail_free_pio_data:
free_page((unsigned long)vcpu->arch.pio_data);
fail:
return r;
}
void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
int idx;
kvm_pmu_destroy(vcpu);
kfree(vcpu->arch.mce_banks);
kvm_free_lapic(vcpu);
idx = srcu_read_lock(&vcpu->kvm->srcu);
kvm_mmu_destroy(vcpu);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
free_page((unsigned long)vcpu->arch.pio_data);
if (!irqchip_in_kernel(vcpu->kvm))
static_key_slow_dec(&kvm_no_apic_vcpu);
}
void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
{
kvm_x86_ops->sched_in(vcpu, cpu);
}
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
if (type)
return -EINVAL;
INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages);
INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
atomic_set(&kvm->arch.noncoherent_dma_count, 0);
/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);
/* Reserve bit 1 of irq_sources_bitmap for irqfd-resampler */
set_bit(KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
&kvm->arch.irq_sources_bitmap);
raw_spin_lock_init(&kvm->arch.tsc_write_lock);
mutex_init(&kvm->arch.apic_map_lock);
spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock);
pvclock_update_vm_gtod_copy(kvm);
INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn);
INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);
return 0;
}
static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
{
int r;
r = vcpu_load(vcpu);
BUG_ON(r);
kvm_mmu_unload(vcpu);
vcpu_put(vcpu);
}
static void kvm_free_vcpus(struct kvm *kvm)
{
unsigned int i;
struct kvm_vcpu *vcpu;
/*
* Unpin any mmu pages first.
*/
kvm_for_each_vcpu(i, vcpu, kvm) {
kvm_clear_async_pf_completion_queue(vcpu);
kvm_unload_vcpu_mmu(vcpu);
}
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_arch_vcpu_free(vcpu);
mutex_lock(&kvm->lock);
for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
kvm->vcpus[i] = NULL;
atomic_set(&kvm->online_vcpus, 0);
mutex_unlock(&kvm->lock);
}
void kvm_arch_sync_events(struct kvm *kvm)
{
cancel_delayed_work_sync(&kvm->arch.kvmclock_sync_work);
cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work);
kvm_free_all_assigned_devices(kvm);
kvm_free_pit(kvm);
}
int __x86_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem)
{
int i, r;
/* Called with kvm->slots_lock held. */
BUG_ON(mem->slot >= KVM_MEM_SLOTS_NUM);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
struct kvm_userspace_memory_region m = *mem;
m.slot |= i << 16;
r = __kvm_set_memory_region(kvm, &m);
if (r < 0)
return r;
}
return 0;
}
EXPORT_SYMBOL_GPL(__x86_set_memory_region);
int x86_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem)
{
int r;
mutex_lock(&kvm->slots_lock);
r = __x86_set_memory_region(kvm, mem);
mutex_unlock(&kvm->slots_lock);
return r;
}
EXPORT_SYMBOL_GPL(x86_set_memory_region);
void kvm_arch_destroy_vm(struct kvm *kvm)
{
if (current->mm == kvm->mm) {
/*
* Free memory regions allocated on behalf of userspace,
* unless the the memory map has changed due to process exit
* or fd copying.
*/
struct kvm_userspace_memory_region mem;
memset(&mem, 0, sizeof(mem));
mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
x86_set_memory_region(kvm, &mem);
mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
x86_set_memory_region(kvm, &mem);
mem.slot = TSS_PRIVATE_MEMSLOT;
x86_set_memory_region(kvm, &mem);
}
kvm_iommu_unmap_guest(kvm);
kfree(kvm->arch.vpic);
kfree(kvm->arch.vioapic);
kvm_free_vcpus(kvm);
kfree(rcu_dereference_check(kvm->arch.apic_map, 1));
}
void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
struct kvm_memory_slot *dont)
{
int i;
for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
if (!dont || free->arch.rmap[i] != dont->arch.rmap[i]) {
kvfree(free->arch.rmap[i]);
free->arch.rmap[i] = NULL;
}
if (i == 0)
continue;
if (!dont || free->arch.lpage_info[i - 1] !=
dont->arch.lpage_info[i - 1]) {
kvfree(free->arch.lpage_info[i - 1]);
free->arch.lpage_info[i - 1] = NULL;
}
}
}
int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
unsigned long npages)
{
int i;
for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
unsigned long ugfn;
int lpages;
int level = i + 1;
lpages = gfn_to_index(slot->base_gfn + npages - 1,
slot->base_gfn, level) + 1;
slot->arch.rmap[i] =
kvm_kvzalloc(lpages * sizeof(*slot->arch.rmap[i]));
if (!slot->arch.rmap[i])
goto out_free;
if (i == 0)
continue;
slot->arch.lpage_info[i - 1] = kvm_kvzalloc(lpages *
sizeof(*slot->arch.lpage_info[i - 1]));
if (!slot->arch.lpage_info[i - 1])
goto out_free;
if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
slot->arch.lpage_info[i - 1][0].write_count = 1;
if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
slot->arch.lpage_info[i - 1][lpages - 1].write_count = 1;
ugfn = slot->userspace_addr >> PAGE_SHIFT;
/*
* If the gfn and userspace address are not aligned wrt each
* other, or if explicitly asked to, disable large page
* support for this slot
*/
if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
!kvm_largepages_enabled()) {
unsigned long j;
for (j = 0; j < lpages; ++j)
slot->arch.lpage_info[i - 1][j].write_count = 1;
}
}
return 0;
out_free:
for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
kvfree(slot->arch.rmap[i]);
slot->arch.rmap[i] = NULL;
if (i == 0)
continue;
kvfree(slot->arch.lpage_info[i - 1]);
slot->arch.lpage_info[i - 1] = NULL;
}
return -ENOMEM;
}
void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
{
/*
* memslots->generation has been incremented.
* mmio generation may have reached its maximum value.
*/
kvm_mmu_invalidate_mmio_sptes(kvm, slots);
}
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
const struct kvm_userspace_memory_region *mem,
enum kvm_mr_change change)
{
/*
* Only private memory slots need to be mapped here since
* KVM_SET_MEMORY_REGION ioctl is no longer supported.
*/
if ((memslot->id >= KVM_USER_MEM_SLOTS) && (change == KVM_MR_CREATE)) {
unsigned long userspace_addr;
/*
* MAP_SHARED to prevent internal slot pages from being moved
* by fork()/COW.
*/
userspace_addr = vm_mmap(NULL, 0, memslot->npages * PAGE_SIZE,
PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, 0);
if (IS_ERR((void *)userspace_addr))
return PTR_ERR((void *)userspace_addr);
memslot->userspace_addr = userspace_addr;
}
return 0;
}
static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
struct kvm_memory_slot *new)
{
/* Still write protect RO slot */
if (new->flags & KVM_MEM_READONLY) {
kvm_mmu_slot_remove_write_access(kvm, new);
return;
}
/*
* Call kvm_x86_ops dirty logging hooks when they are valid.
*
* kvm_x86_ops->slot_disable_log_dirty is called when:
*
* - KVM_MR_CREATE with dirty logging is disabled
* - KVM_MR_FLAGS_ONLY with dirty logging is disabled in new flag
*
* The reason is, in case of PML, we need to set D-bit for any slots
* with dirty logging disabled in order to eliminate unnecessary GPA
* logging in PML buffer (and potential PML buffer full VMEXT). This
* guarantees leaving PML enabled during guest's lifetime won't have
* any additonal overhead from PML when guest is running with dirty
* logging disabled for memory slots.
*
* kvm_x86_ops->slot_enable_log_dirty is called when switching new slot
* to dirty logging mode.
*
* If kvm_x86_ops dirty logging hooks are invalid, use write protect.
*
* In case of write protect:
*
* Write protect all pages for dirty logging.
*
* All the sptes including the large sptes which point to this
* slot are set to readonly. We can not create any new large
* spte on this slot until the end of the logging.
*
* See the comments in fast_page_fault().
*/
if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
if (kvm_x86_ops->slot_enable_log_dirty)
kvm_x86_ops->slot_enable_log_dirty(kvm, new);
else
kvm_mmu_slot_remove_write_access(kvm, new);
} else {
if (kvm_x86_ops->slot_disable_log_dirty)
kvm_x86_ops->slot_disable_log_dirty(kvm, new);
}
}
void kvm_arch_commit_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem,
const struct kvm_memory_slot *old,
const struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
int nr_mmu_pages = 0;
if (change == KVM_MR_DELETE && old->id >= KVM_USER_MEM_SLOTS) {
int ret;
ret = vm_munmap(old->userspace_addr,
old->npages * PAGE_SIZE);
if (ret < 0)
printk(KERN_WARNING
"kvm_vm_ioctl_set_memory_region: "
"failed to munmap memory\n");
}
if (!kvm->arch.n_requested_mmu_pages)
nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
if (nr_mmu_pages)
kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
/*
* Dirty logging tracks sptes in 4k granularity, meaning that large
* sptes have to be split. If live migration is successful, the guest
* in the source machine will be destroyed and large sptes will be
* created in the destination. However, if the guest continues to run
* in the source machine (for example if live migration fails), small
* sptes will remain around and cause bad performance.
*
* Scan sptes if dirty logging has been stopped, dropping those
* which can be collapsed into a single large-page spte. Later
* page faults will create the large-page sptes.
*/
if ((change != KVM_MR_DELETE) &&
(old->flags & KVM_MEM_LOG_DIRTY_PAGES) &&
!(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
kvm_mmu_zap_collapsible_sptes(kvm, new);
/*
* Set up write protection and/or dirty logging for the new slot.
*
* For KVM_MR_DELETE and KVM_MR_MOVE, the shadow pages of old slot have
* been zapped so no dirty logging staff is needed for old slot. For
* KVM_MR_FLAGS_ONLY, the old slot is essentially the same one as the
* new and it's also covered when dealing with the new slot.
*
* FIXME: const-ify all uses of struct kvm_memory_slot.
*/
if (change != KVM_MR_DELETE)
kvm_mmu_slot_apply_flags(kvm, (struct kvm_memory_slot *) new);
}
void kvm_arch_flush_shadow_all(struct kvm *kvm)
{
kvm_mmu_invalidate_zap_all_pages(kvm);
}
void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot)
{
kvm_mmu_invalidate_zap_all_pages(kvm);
}
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
{
if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events)
kvm_x86_ops->check_nested_events(vcpu, false);
return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
!vcpu->arch.apf.halted)
|| !list_empty_careful(&vcpu->async_pf.done)
|| kvm_apic_has_events(vcpu)
|| vcpu->arch.pv.pv_unhalted
|| atomic_read(&vcpu->arch.nmi_queued) ||
(kvm_arch_interrupt_allowed(vcpu) &&
kvm_cpu_has_interrupt(vcpu));
}
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
}
int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
{
return kvm_x86_ops->interrupt_allowed(vcpu);
}
unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu)
{
if (is_64_bit_mode(vcpu))
return kvm_rip_read(vcpu);
return (u32)(get_segment_base(vcpu, VCPU_SREG_CS) +
kvm_rip_read(vcpu));
}
EXPORT_SYMBOL_GPL(kvm_get_linear_rip);
bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip)
{
return kvm_get_linear_rip(vcpu) == linear_rip;
}
EXPORT_SYMBOL_GPL(kvm_is_linear_rip);
unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu)
{
unsigned long rflags;
rflags = kvm_x86_ops->get_rflags(vcpu);
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
rflags &= ~X86_EFLAGS_TF;
return rflags;
}
EXPORT_SYMBOL_GPL(kvm_get_rflags);
static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP &&
kvm_is_linear_rip(vcpu, vcpu->arch.singlestep_rip))
rflags |= X86_EFLAGS_TF;
kvm_x86_ops->set_rflags(vcpu, rflags);
}
void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
__kvm_set_rflags(vcpu, rflags);
kvm_make_request(KVM_REQ_EVENT, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_set_rflags);
void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
{
int r;
if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) ||
work->wakeup_all)
return;
r = kvm_mmu_reload(vcpu);
if (unlikely(r))
return;
if (!vcpu->arch.mmu.direct_map &&
work->arch.cr3 != vcpu->arch.mmu.get_cr3(vcpu))
return;
vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true);
}
static inline u32 kvm_async_pf_hash_fn(gfn_t gfn)
{
return hash_32(gfn & 0xffffffff, order_base_2(ASYNC_PF_PER_VCPU));
}
static inline u32 kvm_async_pf_next_probe(u32 key)
{
return (key + 1) & (roundup_pow_of_two(ASYNC_PF_PER_VCPU) - 1);
}
static void kvm_add_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
u32 key = kvm_async_pf_hash_fn(gfn);
while (vcpu->arch.apf.gfns[key] != ~0)
key = kvm_async_pf_next_probe(key);
vcpu->arch.apf.gfns[key] = gfn;
}
static u32 kvm_async_pf_gfn_slot(struct kvm_vcpu *vcpu, gfn_t gfn)
{
int i;
u32 key = kvm_async_pf_hash_fn(gfn);
for (i = 0; i < roundup_pow_of_two(ASYNC_PF_PER_VCPU) &&
(vcpu->arch.apf.gfns[key] != gfn &&
vcpu->arch.apf.gfns[key] != ~0); i++)
key = kvm_async_pf_next_probe(key);
return key;
}
bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
return vcpu->arch.apf.gfns[kvm_async_pf_gfn_slot(vcpu, gfn)] == gfn;
}
static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
u32 i, j, k;
i = j = kvm_async_pf_gfn_slot(vcpu, gfn);
while (true) {
vcpu->arch.apf.gfns[i] = ~0;
do {
j = kvm_async_pf_next_probe(j);
if (vcpu->arch.apf.gfns[j] == ~0)
return;
k = kvm_async_pf_hash_fn(vcpu->arch.apf.gfns[j]);
/*
* k lies cyclically in ]i,j]
* | i.k.j |
* |....j i.k.| or |.k..j i...|
*/
} while ((i <= j) ? (i < k && k <= j) : (i < k || k <= j));
vcpu->arch.apf.gfns[i] = vcpu->arch.apf.gfns[j];
i = j;
}
}
static int apf_put_user(struct kvm_vcpu *vcpu, u32 val)
{
return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &val,
sizeof(val));
}
void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
struct kvm_async_pf *work)
{
struct x86_exception fault;
trace_kvm_async_pf_not_present(work->arch.token, work->gva);
kvm_add_async_pf_gfn(vcpu, work->arch.gfn);
if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) ||
(vcpu->arch.apf.send_user_only &&
kvm_x86_ops->get_cpl(vcpu) == 0))
kvm_make_request(KVM_REQ_APF_HALT, vcpu);
else if (!apf_put_user(vcpu, KVM_PV_REASON_PAGE_NOT_PRESENT)) {
fault.vector = PF_VECTOR;
fault.error_code_valid = true;
fault.error_code = 0;
fault.nested_page_fault = false;
fault.address = work->arch.token;
kvm_inject_page_fault(vcpu, &fault);
}
}
void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
struct kvm_async_pf *work)
{
struct x86_exception fault;
trace_kvm_async_pf_ready(work->arch.token, work->gva);
if (work->wakeup_all)
work->arch.token = ~0; /* broadcast wakeup */
else
kvm_del_async_pf_gfn(vcpu, work->arch.gfn);
if ((vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) &&
!apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) {
fault.vector = PF_VECTOR;
fault.error_code_valid = true;
fault.error_code = 0;
fault.nested_page_fault = false;
fault.address = work->arch.token;
kvm_inject_page_fault(vcpu, &fault);
}
vcpu->arch.apf.halted = false;
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
}
bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu)
{
if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED))
return true;
else
return !kvm_event_needs_reinjection(vcpu) &&
kvm_x86_ops->interrupt_allowed(vcpu);
}
void kvm_arch_start_assignment(struct kvm *kvm)
{
atomic_inc(&kvm->arch.assigned_device_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_start_assignment);
void kvm_arch_end_assignment(struct kvm *kvm)
{
atomic_dec(&kvm->arch.assigned_device_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_end_assignment);
bool kvm_arch_has_assigned_device(struct kvm *kvm)
{
return atomic_read(&kvm->arch.assigned_device_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);
void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
{
atomic_inc(&kvm->arch.noncoherent_dma_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma);
void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
{
atomic_dec(&kvm->arch.noncoherent_dma_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma);
bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
{
return atomic_read(&kvm->arch.noncoherent_dma_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_msr);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_cr);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmrun);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit_inject);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intr_vmexit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
kvm: Add a tracepoint write_tsc_offset Add a tracepoint write_tsc_offset for tracing TSC offset change. We want to merge ftrace's trace data of guest OSs and the host OS using TSC for timestamp in chronological order. We need "TSC offset" values for each guest when merge those because the TSC value on a guest is always the host TSC plus guest's TSC offset. If we get the TSC offset values, we can calculate the host TSC value for each guest events from the TSC offset and the event TSC value. The host TSC values of the guest events are used when we want to merge trace data of guests and the host in chronological order. (Note: the trace_clock of both the host and the guest must be set x86-tsc in this case) This tracepoint also records vcpu_id which can be used to merge trace data for SMP guests. A merge tool will read TSC offset for each vcpu, then the tool converts guest TSC values to host TSC values for each vcpu. TSC offset is stored in the VMCS by vmx_write_tsc_offset() or vmx_adjust_tsc_offset(). KVM executes the former function when a guest boots. The latter function is executed when kvm clock is updated. Only host can read TSC offset value from VMCS, so a host needs to output TSC offset value when TSC offset is changed. Since the TSC offset is not often changed, it could be overwritten by other frequent events while tracing. To avoid that, I recommend to use a special instance for getting this event: 1. set a instance before booting a guest # cd /sys/kernel/debug/tracing/instances # mkdir tsc_offset # cd tsc_offset # echo x86-tsc > trace_clock # echo 1 > events/kvm/kvm_write_tsc_offset/enable 2. boot a guest Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-12 07:43:44 +00:00
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full);