Variable MTRR MSRs are 64 bits which are directly accessed with full length,
no reason to split them to two 32 bits
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop kvm_mtrr->enable, omit the decode/code workload and get rid of
all the hard code
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Only KVM_NR_VAR_MTRR variable MTRRs are available in KVM guest
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vMTRR does not depend on any host MTRR feature and fixed MTRRs have always
been implemented, so drop this field
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MTRR code locates in x86.c and mmu.c so that move them to a separate file to
make the organization more clearer and it will be the place where we fully
implement vMTRR
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
... and we're done. :)
Because SMBASE is usually relocated above 1M on modern chipsets, and
SMM handlers might indeed rely on 4G segment limits, we only expose it
if KVM is able to run the guest in big real mode. This includes any
of VMX+emulate_invalid_guest_state, VMX+unrestricted_guest, or SVM.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is now very simple to do. The only interesting part is a simple
trick to find the right memslot in gfn_to_rmap, retrieving the address
space from the spte role word. The same trick is used in the auditing
code.
The comment on top of union kvm_mmu_page_role has been stale forever,
so remove it. Speaking of stale code, remove pad_for_nice_hex_output
too: it was splitting the "access" bitfield across two bytes and thus
had effectively turned into pad_for_ugly_hex_output.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch has no semantic change, but it prepares for the introduction
of a second address space for system management mode.
A new function x86_set_memory_region (and the "slots_lock taken"
counterpart __x86_set_memory_region) is introduced in order to
operate on all address spaces when adding or deleting private
memory slots.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We need to hide SMRAM from guests not running in SMM. Therefore,
all uses of kvm_read_guest* and kvm_write_guest* must be changed to
check whether the VCPU is in system management mode and use a
different set of memslots. Switch from kvm_* to the newly-introduced
kvm_vcpu_*, which call into kvm_arch_vcpu_memslots_id.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds the interface between x86.c and the emulator: the
SMBASE register, a new emulator flag, the RSM instruction. It also
adds a new request bit that will be used by the KVM_SMI ioctl.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch includes changes to the external API for SMM support.
Userspace can predicate the availability of the new fields and
ioctls on a new capability, KVM_CAP_X86_SMM, which is added at the end
of the patch series.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SMBASE is only readable from SMM for the VCPU, but it must be always
accessible if userspace is accessing it. Thus, all functions that
read MSRs are changed to accept a struct msr_data; the host_initiated
and index fields are pre-initialized, while the data field is filled
on return.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This lets the function access the new memory slot without going through
kvm_memslots and id_to_memslot. It will simplify the code when more
than one address space will be supported.
Unfortunately, the "const"ness of the new argument must be casted
away in two places. Fixing KVM to accept const struct kvm_memory_slot
pointers would require modifications in pretty much all architectures,
and is left for later.
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The MPX feature requires eager KVM FPU restore support. We have verified
that MPX cannot work correctly with the current lazy KVM FPU restore
mechanism. Eager KVM FPU restore should be enabled if the MPX feature is
exposed to VM.
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Signed-off-by: Liang Li <liang.z.li@intel.com>
[Also activate the FPU on AMD processors. - Paolo]
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM may turn a user page to a kernel page when kernel writes a readonly
user page if CR0.WP = 1. This shadow page entry will be reused after
SMAP is enabled so that kernel is allowed to access this user page
Fix it by setting SMAP && !CR0.WP into shadow page's role and reset mmu
once CR4.SMAP is updated
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM may turn a user page to a kernel page when kernel writes a readonly
user page if CR0.WP = 1. This shadow page entry will be reused after
SMAP is enabled so that kernel is allowed to access this user page
Fix it by setting SMAP && !CR0.WP into shadow page's role and reset mmu
once CR4.SMAP is updated
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Extended struct kvm_lapic_irq with bool msi_redir_hint, which will
be used to determine if the delivery of the MSI should target only
the lowest priority CPU in the logical group specified for delivery.
(In physical dest mode, the RH bit is not relevant). Initialized the value
of msi_redir_hint to true when RH=1 in kvm_set_msi_irq(), and initialized
to false in all other cases.
Added value of msi_redir_hint to a debug message dump of an IRQ in
apic_send_ipi().
Signed-off-by: James Sullivan <sullivan.james.f@gmail.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Change to u16 if they only contain data in the low 16 bits.
Change the level field to bool, since we assign 1 sometimes, but
just mask icr_low with APIC_INT_ASSERT in apic_send_ipi.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86 architecture defines differences between the reset and INIT sequences.
INIT does not initialize the FPU (including MMX, XMM, YMM, etc.), TSC, PMU,
MSRs (in general), MTRRs machine-check, APIC ID, APIC arbitration ID and BSP.
References (from Intel SDM):
"If the MP protocol has completed and a BSP is chosen, subsequent INITs (either
to a specific processor or system wide) do not cause the MP protocol to be
repeated." [8.4.2: MP Initialization Protocol Requirements and Restrictions]
[Table 9-1. IA-32 Processor States Following Power-up, Reset, or INIT]
"If the processor is reset by asserting the INIT# pin, the x87 FPU state is not
changed." [9.2: X87 FPU INITIALIZATION]
"The state of the local APIC following an INIT reset is the same as it is after
a power-up or hardware reset, except that the APIC ID and arbitration ID
registers are not affected." [10.4.7.3: Local APIC State After an INIT Reset
("Wait-for-SIPI" State)]
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1428924848-28212-1-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introducing KVM_CAP_DISABLE_QUIRKS for disabling x86 quirks that were previous
created in order to overcome QEMU issues. Those issue were mostly result of
invalid VM BIOS. Currently there are two quirks that can be disabled:
1. KVM_QUIRK_LINT0_REENABLED - LINT0 was enabled after boot
2. KVM_QUIRK_CD_NW_CLEARED - CD and NW are cleared after boot
These two issues are already resolved in recent releases of QEMU, and would
therefore be disabled by QEMU.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1428879221-29996-1-git-send-email-namit@cs.technion.ac.il>
[Report capability from KVM_CHECK_EXTENSION too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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, the guest continues to run in the source machine
(for example if live migration fails), small sptes will remain around
and cause bad performance.
This patch introduce lazy collapsing of small sptes into large sptes.
The rmap will be scanned in ioctl context when dirty logging is stopped,
dropping those sptes which can be collapsed into a single large-page spte.
Later page faults will create the large-page sptes.
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Message-Id: <1428046825-6905-1-git-send-email-wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DR0-DR3 are not cleared as they should during reset and when they are set from
userspace. It appears to be caused by c77fb5fe6f ("KVM: x86: Allow the guest
to run with dirty debug registers").
Force their reload on these situations.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427933438-12782-4-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
recalculate_apic_map() uses two passes over all VCPUs. This is a relic
from time when we selected a global mode in the first pass and set up
the optimized table in the second pass (to have a consistent mode).
Recent changes made mixed mode unoptimized and we can do it in one pass.
Format of logical MDA is a function of the mode, so we encode it in
apic_logical_id() and drop obsoleted variables from the struct.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-5-git-send-email-rkrcmar@redhat.com>
[Add lid_bits temporary in apic_logical_id. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We want to support mixed modes and the easiest solution is to avoid
optimizing those weird and unlikely scenarios.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-4-git-send-email-rkrcmar@redhat.com>
[Add comment above KVM_APIC_MODE_* defines. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Broadcast allowed only one global APIC mode, but mixed modes are
theoretically possible. x2APIC IPI doesn't mean 0xff as broadcast,
the rest does.
x2APIC broadcasts are accepted by xAPIC. If we take SDM to be logical,
even addreses beginning with 0xff should be accepted, but real hardware
disagrees. This patch aims for simple code by considering most of real
behavior as undefined.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1423766494-26150-3-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cpuid_maxphyaddr(), which performs lot of memory accesses is called
extensively across KVM, especially in nVMX code.
This patch adds a cached value of maxphyaddr to vcpu.arch to reduce the
pressure onto CPU cache and simplify the code of cpuid_maxphyaddr()
callers. The cached value is initialized in kvm_arch_vcpu_init() and
reloaded every time CPUID is updated by usermode. It is obvious that
these reloads occur infrequently.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205612.GA1223@gnote>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some constants are redfined in emulate.c. Avoid it.
s/SELECTOR_RPL_MASK/SEGMENT_RPL_MASK
s/SELECTOR_TI_MASK/SEGMENT_TI_MASK
No functional change.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427635984-8113-3-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The eflags are redefined (using other defines) in emulate.c.
Use the definition from processor-flags.h as some mess already started.
No functional change.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427635984-8113-2-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently kvm_emulate() skips the instruction but kvm_emulate_* sometimes
don't. The end reult is the caller ends up doing the skip themselves.
Let's make them consistant.
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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>
Revert 7c6a98dfa1, given
that testing PIR is not necessary anymore.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds new kvm_x86_ops dirty logging hooks to enable/disable dirty
logging for particular memory slot, and to flush potentially logged dirty GPAs
before reporting slot->dirty_bitmap to userspace.
kvm x86 common code calls these hooks when they are available so PML logic can
be hidden to VMX specific. SVM won't be impacted as these hooks remain NULL
there.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch changes the second parameter of kvm_mmu_slot_remove_write_access from
'slot id' to 'struct kvm_memory_slot *' to align with kvm_x86_ops dirty logging
hooks, which will be introduced in further patch.
Better way is to change second parameter of kvm_arch_commit_memory_region from
'struct kvm_userspace_memory_region *' to 'struct kvm_memory_slot * new', but it
requires changes on other non-x86 ARCH too, so avoid it now.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds new mmu layer functions to clear/set D-bit for memory slot, and
to write protect superpages for memory slot.
In case of PML, CPU logs the dirty GPA automatically to PML buffer when CPU
updates D-bit from 0 to 1, therefore we don't have to write protect 4K pages,
instead, we only need to clear D-bit in order to log that GPA.
For superpages, we still write protect it and let page fault code to handle
dirty page logging, as we still need to split superpage to 4K pages in PML.
As PML is always enabled during guest's lifetime, to eliminate unnecessary PML
GPA logging, we set D-bit manually for the slot with dirty logging disabled.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/emulate.c: In function ‘check_cr_write’:
arch/x86/kvm/emulate.c:3552:4: warning: left shift count >= width of type
rsvd = CR3_L_MODE_RESERVED_BITS & ~CR3_PCID_INVD;
happens because sizeof(UL) on 32-bit is 4 bytes but we shift it 63 bits
to the left.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SuSE's 2.6.16 kernel fails to boot if the delta between tsc_timestamp
and rdtsc is larger than a given threshold:
* If we get more than the below threshold into the future, we rerequest
* the real time from the host again which has only little offset then
* that we need to adjust using the TSC.
*
* For now that threshold is 1/5th of a jiffie. That should be good
* enough accuracy for completely broken systems, but also give us swing
* to not call out to the host all the time.
*/
#define PVCLOCK_DELTA_MAX ((1000000000ULL / HZ) / 5)
Disable masterclock support (which increases said delta) in case the
boot vcpu does not use MSR_KVM_SYSTEM_TIME_NEW.
Upstreams kernels which support pvclock vsyscalls (and therefore make
use of PVCLOCK_STABLE_BIT) use MSR_KVM_SYSTEM_TIME_NEW.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We now have a generic function that does most of the work of
kvm_vm_ioctl_get_dirty_log, now use it.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
When emulating an instruction that reads the destination memory operand (i.e.,
instructions without the Mov flag in the emulator), the operand is first read.
If a page-fault is detected in this phase, the error-code which would be
delivered to the VM does not indicate that the access that caused the exception
is a write one. This does not conform with real hardware, and may cause the VM
to enter the page-fault handler twice for no reason (once for read, once for
write).
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_x86_ops->test_posted_interrupt() returns true/false depending
whether 'vector' is set.
Next patch makes use of this interface.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add logic to get/set the XSS model-specific register.
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Expose the XSAVES feature to the guest if the kvm_x86_ops say it is
available.
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cs.base is declared as a __u64 variable and vector is a u32 so this
causes a static checker warning. The user indeed can set "sipi_vector"
to any u32 value in kvm_vcpu_ioctl_x86_set_vcpu_events(), but the
value should really have 8-bit precision only.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create a new header, and hide the device assignment functions there.
Move struct kvm_assigned_dev_kernel to assigned-dev.c by modifying
arch/x86/kvm/iommu.c to take a PCI device struct.
Based on a patch by Radim Krcmar <rkrcmark@redhat.com>.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that ia64 is gone, we can hide deprecated device assignment in x86.
Notable changes:
- kvm_vm_ioctl_assigned_device() was moved to x86/kvm_arch_vm_ioctl()
The easy parts were removed from generic kvm code, remaining
- kvm_iommu_(un)map_pages() would require new code to be moved
- struct kvm_assigned_dev_kernel depends on struct kvm_irq_ack_notifier
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
ia64 does not need them anymore. Ack notifiers become x86-specific
too.
Suggested-by: Gleb Natapov <gleb@kernel.org>
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
