linux/arch/powerpc/kvm/powerpc.c
Hollis Blanchard 73e75b416f KVM: ppc: Implement in-kernel exit timing statistics
Existing KVM statistics are either just counters (kvm_stat) reported for
KVM generally or trace based aproaches like kvm_trace.
For KVM on powerpc we had the need to track the timings of the different exit
types. While this could be achieved parsing data created with a kvm_trace
extension this adds too much overhead (at least on embedded PowerPC) slowing
down the workloads we wanted to measure.

Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm
code. These statistic is available per vm&vcpu under the kvm debugfs directory.
As this statistic is low, but still some overhead it can be enabled via a
.config entry and should be off by default.

Since this patch touched all powerpc kvm_stat code anyway this code is now
merged and simplified together with the exit timing statistic code (still
working with exit timing disabled in .config).

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:41 +02:00

458 lines
9.8 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright IBM Corp. 2007
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
* Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <asm/cputable.h>
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
#include <asm/tlbflush.h>
#include "timing.h"
#include "../mm/mmu_decl.h"
gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
{
return gfn;
}
int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
{
return !!(v->arch.pending_exceptions);
}
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
return !(v->arch.msr & MSR_WE);
}
int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
enum emulation_result er;
int r;
er = kvmppc_emulate_instruction(run, vcpu);
switch (er) {
case EMULATE_DONE:
/* Future optimization: only reload non-volatiles if they were
* actually modified. */
r = RESUME_GUEST_NV;
break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
/* We must reload nonvolatiles because "update" load/store
* instructions modify register state. */
/* Future optimization: only reload non-volatiles if they were
* actually modified. */
r = RESUME_HOST_NV;
break;
case EMULATE_FAIL:
/* XXX Deliver Program interrupt to guest. */
printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
vcpu->arch.last_inst);
r = RESUME_HOST;
break;
default:
BUG();
}
return r;
}
void kvm_arch_hardware_enable(void *garbage)
{
}
void kvm_arch_hardware_disable(void *garbage)
{
}
int kvm_arch_hardware_setup(void)
{
return 0;
}
void kvm_arch_hardware_unsetup(void)
{
}
void kvm_arch_check_processor_compat(void *rtn)
{
*(int *)rtn = kvmppc_core_check_processor_compat();
}
struct kvm *kvm_arch_create_vm(void)
{
struct kvm *kvm;
kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
if (!kvm)
return ERR_PTR(-ENOMEM);
return kvm;
}
static void kvmppc_free_vcpus(struct kvm *kvm)
{
unsigned int i;
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
if (kvm->vcpus[i]) {
kvm_arch_vcpu_free(kvm->vcpus[i]);
kvm->vcpus[i] = NULL;
}
}
}
void kvm_arch_destroy_vm(struct kvm *kvm)
{
kvmppc_free_vcpus(kvm);
kvm_free_physmem(kvm);
kfree(kvm);
}
int kvm_dev_ioctl_check_extension(long ext)
{
int r;
switch (ext) {
case KVM_CAP_USER_MEMORY:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
break;
default:
r = 0;
break;
}
return r;
}
long kvm_arch_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
return -EINVAL;
}
int kvm_arch_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
struct kvm_memory_slot old,
int user_alloc)
{
return 0;
}
void kvm_arch_flush_shadow(struct kvm *kvm)
{
}
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
struct kvm_vcpu *vcpu;
vcpu = kvmppc_core_vcpu_create(kvm, id);
kvmppc_create_vcpu_debugfs(vcpu, id);
return vcpu;
}
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
kvmppc_remove_vcpu_debugfs(vcpu);
kvmppc_core_vcpu_free(vcpu);
}
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
kvm_arch_vcpu_free(vcpu);
}
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
return kvmppc_core_pending_dec(vcpu);
}
static void kvmppc_decrementer_func(unsigned long data)
{
struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
kvmppc_core_queue_dec(vcpu);
if (waitqueue_active(&vcpu->wq)) {
wake_up_interruptible(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
}
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
setup_timer(&vcpu->arch.dec_timer, kvmppc_decrementer_func,
(unsigned long)vcpu);
return 0;
}
void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
kvmppc_core_destroy_mmu(vcpu);
}
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
if (vcpu->guest_debug.enabled)
kvmppc_core_load_guest_debugstate(vcpu);
kvmppc_core_vcpu_load(vcpu, cpu);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_debug.enabled)
kvmppc_core_load_host_debugstate(vcpu);
/* Don't leave guest TLB entries resident when being de-scheduled. */
/* XXX It would be nice to differentiate between heavyweight exit and
* sched_out here, since we could avoid the TLB flush for heavyweight
* exits. */
_tlbil_all();
kvmppc_core_vcpu_put(vcpu);
}
int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
struct kvm_debug_guest *dbg)
{
int i;
vcpu->guest_debug.enabled = dbg->enabled;
if (vcpu->guest_debug.enabled) {
for (i=0; i < ARRAY_SIZE(vcpu->guest_debug.bp); i++) {
if (dbg->breakpoints[i].enabled)
vcpu->guest_debug.bp[i] = dbg->breakpoints[i].address;
else
vcpu->guest_debug.bp[i] = 0;
}
}
return 0;
}
static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu,
struct kvm_run *run)
{
ulong *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
*gpr = run->dcr.data;
}
static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
struct kvm_run *run)
{
ulong *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
if (run->mmio.len > sizeof(*gpr)) {
printk(KERN_ERR "bad MMIO length: %d\n", run->mmio.len);
return;
}
if (vcpu->arch.mmio_is_bigendian) {
switch (run->mmio.len) {
case 4: *gpr = *(u32 *)run->mmio.data; break;
case 2: *gpr = *(u16 *)run->mmio.data; break;
case 1: *gpr = *(u8 *)run->mmio.data; break;
}
} else {
/* Convert BE data from userland back to LE. */
switch (run->mmio.len) {
case 4: *gpr = ld_le32((u32 *)run->mmio.data); break;
case 2: *gpr = ld_le16((u16 *)run->mmio.data); break;
case 1: *gpr = *(u8 *)run->mmio.data; break;
}
}
}
int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int rt, unsigned int bytes, int is_bigendian)
{
if (bytes > sizeof(run->mmio.data)) {
printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr = vcpu->arch.paddr_accessed;
run->mmio.len = bytes;
run->mmio.is_write = 0;
vcpu->arch.io_gpr = rt;
vcpu->arch.mmio_is_bigendian = is_bigendian;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 0;
return EMULATE_DO_MMIO;
}
int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
u32 val, unsigned int bytes, int is_bigendian)
{
void *data = run->mmio.data;
if (bytes > sizeof(run->mmio.data)) {
printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr = vcpu->arch.paddr_accessed;
run->mmio.len = bytes;
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
/* Store the value at the lowest bytes in 'data'. */
if (is_bigendian) {
switch (bytes) {
case 4: *(u32 *)data = val; break;
case 2: *(u16 *)data = val; break;
case 1: *(u8 *)data = val; break;
}
} else {
/* Store LE value into 'data'. */
switch (bytes) {
case 4: st_le32(data, val); break;
case 2: st_le16(data, val); break;
case 1: *(u8 *)data = val; break;
}
}
return EMULATE_DO_MMIO;
}
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
int r;
sigset_t sigsaved;
vcpu_load(vcpu);
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
if (vcpu->mmio_needed) {
if (!vcpu->mmio_is_write)
kvmppc_complete_mmio_load(vcpu, run);
vcpu->mmio_needed = 0;
} else if (vcpu->arch.dcr_needed) {
if (!vcpu->arch.dcr_is_write)
kvmppc_complete_dcr_load(vcpu, run);
vcpu->arch.dcr_needed = 0;
}
kvmppc_core_deliver_interrupts(vcpu);
local_irq_disable();
kvm_guest_enter();
r = __kvmppc_vcpu_run(run, vcpu);
kvm_guest_exit();
local_irq_enable();
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
vcpu_put(vcpu);
return r;
}
int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
kvmppc_core_queue_external(vcpu, irq);
if (waitqueue_active(&vcpu->wq)) {
wake_up_interruptible(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
return 0;
}
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
return -EINVAL;
}
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
return -EINVAL;
}
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;
long r;
switch (ioctl) {
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;
}
default:
r = -EINVAL;
}
out:
return r;
}
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
{
return -ENOTSUPP;
}
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
long r;
switch (ioctl) {
default:
r = -EINVAL;
}
return r;
}
int kvm_arch_init(void *opaque)
{
return 0;
}
void kvm_arch_exit(void)
{
}