Commit Graph

901016 Commits

Author SHA1 Message Date
Sean Christopherson
0774a964ef KVM: Fix out of range accesses to memslots
Reset the LRU slot if it becomes invalid when deleting a memslot to fix
an out-of-bounds/use-after-free access when searching through memslots.

Explicitly check for there being no used slots in search_memslots(), and
in the caller of s390's approximation variant.

Fixes: 36947254e5 ("KVM: Dynamically size memslot array based on number of used slots")
Reported-by: Qian Cai <cai@lca.pw>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200320205546.2396-2-sean.j.christopherson@intel.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-26 05:58:27 -04:00
Wanpeng Li
d5361678e6 KVM: X86: Micro-optimize IPI fastpath delay
This patch optimizes the virtual IPI fastpath emulation sequence:

write ICR2                          send virtual IPI
read ICR2                           write ICR2
send virtual IPI         ==>        write ICR
write ICR

We can observe ~0.67% performance improvement for IPI microbenchmark
(https://lore.kernel.org/kvm/20171219085010.4081-1-ynorov@caviumnetworks.com/)
on Skylake server.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1585189202-1708-4-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-26 05:58:26 -04:00
Wanpeng Li
8a1038de11 KVM: X86: Delay read msr data iff writes ICR MSR
Delay read msr data until we identify guest accesses ICR MSR to avoid
to penalize all other MSR writes.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1585189202-1708-2-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-26 05:58:25 -04:00
Sean Christopherson
4f6ea0a876 KVM: VMX: Gracefully handle faults on VMXON
Gracefully handle faults on VMXON, e.g. #GP due to VMX being disabled by
BIOS, instead of letting the fault crash the system.  Now that KVM uses
cpufeatures to query support instead of reading MSR_IA32_FEAT_CTL
directly, it's possible for a bug in a different subsystem to cause KVM
to incorrectly attempt VMXON[*].  Crashing the system is especially
annoying if the system is configured such that hardware_enable() will
be triggered during boot.

Oppurtunistically rename @addr to @vmxon_pointer and use a named param
to reference it in the inline assembly.

Print 0xdeadbeef in the ultra-"rare" case that reading MSR_IA32_FEAT_CTL
also faults.

[*] https://lkml.kernel.org/r/20200226231615.13664-1-sean.j.christopherson@intel.com
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321193751.24985-4-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:26 -04:00
Sean Christopherson
d260f9ef50 KVM: VMX: Fold loaded_vmcs_init() into alloc_loaded_vmcs()
Subsume loaded_vmcs_init() into alloc_loaded_vmcs(), its only remaining
caller, and drop the VMCLEAR on the shadow VMCS, which is guaranteed to
be NULL.  loaded_vmcs_init() was previously used by loaded_vmcs_clear(),
but loaded_vmcs_clear() also subsumed loaded_vmcs_init() to properly
handle smp_wmb() with respect to VMCLEAR.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321193751.24985-3-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:26 -04:00
Sean Christopherson
31603d4fc2 KVM: VMX: Always VMCLEAR in-use VMCSes during crash with kexec support
VMCLEAR all in-use VMCSes during a crash, even if kdump's NMI shootdown
interrupted a KVM update of the percpu in-use VMCS list.

Because NMIs are not blocked by disabling IRQs, it's possible that
crash_vmclear_local_loaded_vmcss() could be called while the percpu list
of VMCSes is being modified, e.g. in the middle of list_add() in
vmx_vcpu_load_vmcs().  This potential corner case was called out in the
original commit[*], but the analysis of its impact was wrong.

Skipping the VMCLEARs is wrong because it all but guarantees that a
loaded, and therefore cached, VMCS will live across kexec and corrupt
memory in the new kernel.  Corruption will occur because the CPU's VMCS
cache is non-coherent, i.e. not snooped, and so the writeback of VMCS
memory on its eviction will overwrite random memory in the new kernel.
The VMCS will live because the NMI shootdown also disables VMX, i.e. the
in-progress VMCLEAR will #UD, and existing Intel CPUs do not flush the
VMCS cache on VMXOFF.

Furthermore, interrupting list_add() and list_del() is safe due to
crash_vmclear_local_loaded_vmcss() using forward iteration.  list_add()
ensures the new entry is not visible to forward iteration unless the
entire add completes, via WRITE_ONCE(prev->next, new).  A bad "prev"
pointer could be observed if the NMI shootdown interrupted list_del() or
list_add(), but list_for_each_entry() does not consume ->prev.

In addition to removing the temporary disabling of VMCLEAR, open code
loaded_vmcs_init() in __loaded_vmcs_clear() and reorder VMCLEAR so that
the VMCS is deleted from the list only after it's been VMCLEAR'd.
Deleting the VMCS before VMCLEAR would allow a race where the NMI
shootdown could arrive between list_del() and vmcs_clear() and thus
neither flow would execute a successful VMCLEAR.  Alternatively, more
code could be moved into loaded_vmcs_init(), but that gets rather silly
as the only other user, alloc_loaded_vmcs(), doesn't need the smp_wmb()
and would need to work around the list_del().

Update the smp_*() comments related to the list manipulation, and
opportunistically reword them to improve clarity.

[*] https://patchwork.kernel.org/patch/1675731/#3720461

Fixes: 8f536b7697 ("KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321193751.24985-2-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:25 -04:00
Zhenyu Wang
e3747407c4 KVM: x86: Expose fast short REP MOV for supported cpuid
For CPU supporting fast short REP MOV (XF86_FEATURE_FSRM) e.g Icelake,
Tigerlake, expose it in KVM supported cpuid as well.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Message-Id: <20200323092236.3703-1-zhenyuw@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:24 -04:00
Stefan Raspl
0c794dcefb tools/kvm_stat: add command line switch '-c' to log in csv format
Add an alternative format that can be more easily used for further
processing later on.
Note that we add a timestamp in the first column for both, the regular
and the new csv format.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Message-Id: <20200306114250.57585-5-raspl@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:21 -04:00
Stefan Raspl
3cbb394d9f tools/kvm_stat: add command line switch '-s' to set update interval
This now controls both, the refresh rate of the interactive mode as well
as the logging mode. Which, as a consequence, means that the default of
logging mode is now 3s, too (use command line switch '-s' to adjust to
your liking).

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Message-Id: <20200306114250.57585-4-raspl@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:20 -04:00
Stefan Raspl
0e6618fba8 tools/kvm_stat: switch to argparse
optparse is deprecated for a while, hence switching over to argparse
(which also works with python2).
As a consequence, help output has some subtle changes, the most
significant one being that the options are all listed explicitly
instead of a universal '[options]' indicator. Also, some of the error
messages are phrased slightly different.
While at it, squashed a number of minor PEP8 issues.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Message-Id: <20200306114250.57585-3-raspl@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:20 -04:00
Stefan Raspl
eecda7a956 tools/kvm_stat: rework command line sequence and message texts
Make sure command line arguments are sorted alphabetically
everywhere, and adjusted existing texts for interactive command 's' to
become consistent with the long form --set-delay.
Throwing in some PEP8 fixes (all cosmetics) for good measure.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Message-Id: <20200306114250.57585-2-raspl@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:19 -04:00
Andrew Jones
bfcaa84975 KVM: selftests: Rework timespec functions and usage
The steal_time test's timespec stop condition was wrong and should have
used the timespec functions instead to avoid being wrong, but
timespec_diff had a strange interface. Rework all the timespec API and
its use.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 14:08:56 +01:00
Xiaoyao Li
cf6c26ec7b KVM: x86: Code style cleanup in kvm_arch_dev_ioctl()
In kvm_arch_dev_ioctl(), the brackets of case KVM_X86_GET_MCE_CAP_SUPPORTED
accidently encapsulates case KVM_GET_MSR_FEATURE_INDEX_LIST and case
KVM_GET_MSRS. It doesn't affect functionality but it's misleading.

Remove unnecessary brackets and opportunistically add a "break" in the
default path.

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 14:05:45 +01:00
Sean Christopherson
2b110b6164 KVM: x86: Add blurb to CPUID tracepoint when using max basic leaf values
Tack on "used max basic" at the end of the CPUID tracepoint when the
output values correspond to the max basic leaf, i.e. when emulating
Intel's out-of-range CPUID behavior.  Observing "cpuid entry not found"
in the tracepoint with non-zero output values is confusing for users
that aren't familiar with the out-of-range semantics, and qualifying the
"not found" case hopefully makes it clear that "found" means "found the
exact entry".

Suggested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 13:44:43 +01:00
Sean Christopherson
e7adda2810 KVM: x86: Add requested index to the CPUID tracepoint
Output the requested index when tracing CPUID emulation; it's basically
mandatory for leafs where the index is meaningful, and is helpful for
verifying KVM correctness even when the index isn't meaningful, e.g. the
trace for a Linux guest's hypervisor_cpuid_base() probing appears to
be broken (returns all zeroes) at first glance, but is correct because
the index is non-zero, i.e. the output values correspond to a random
index in the maximum basic leaf.

Suggested-by: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 13:44:18 +01:00
Paolo Bonzini
d55c9d4009 KVM: nSVM: check for EFER.SVME=1 before entering guest
EFER is set for L2 using svm_set_efer, which hardcodes EFER_SVME to 1 and hides
an incorrect value for EFER.SVME in the L1 VMCB.  Perform the check manually
to detect invalid guest state.

Reported-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 13:41:32 +01:00
Zhenyu Wang
9401f2e5b0 KVM: x86: Expose AVX512 VP2INTERSECT in cpuid for TGL
On Tigerlake new AVX512 VP2INTERSECT feature is available.
This allows to expose it via KVM_GET_SUPPORTED_CPUID.

Cc: "Zhong, Yang" <yang.zhong@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 12:25:45 +01:00
Paolo Bonzini
96b100cd14 KVM: nVMX: remove side effects from nested_vmx_exit_reflected
The name of nested_vmx_exit_reflected suggests that it's purely
a test, but it actually marks VMCS12 pages as dirty.  Move this to
vmx_handle_exit, observing that the initial nested_run_pending check in
nested_vmx_exit_reflected is pointless---nested_run_pending has just
been cleared in vmx_vcpu_run and won't be set until handle_vmlaunch
or handle_vmresume.

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 12:16:39 +01:00
Uros Bizjak
bb03911f79 KVM: VMX: access regs array in vmenter.S in its natural order
Registers in "regs" array are indexed as rax/rcx/rdx/.../rsi/rdi/r8/...
Reorder access to "regs" array in vmenter.S to follow its natural order.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-17 14:14:32 +01:00
Paolo Bonzini
1c482452d5 KVM: s390: Features and Enhancements for 5.7 part1
1. Allow to disable gisa
 2. protected virtual machines
   Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's
   state like guest memory and guest registers anymore. Instead the
   PVMs are mostly managed by a new entity called Ultravisor (UV),
   which provides an API, so KVM and the PV can request management
   actions.
 
   PVMs are encrypted at rest and protected from hypervisor access
   while running.  They switch from a normal operation into protected
   mode, so we can still use the standard boot process to load a
   encrypted blob and then move it into protected mode.
 
   Rebooting is only possible by passing through the unprotected/normal
   mode and switching to protected again.
 
   One mm related patch will go via Andrews mm tree ( mm/gup/writeback:
   add callbacks for inaccessible pages)
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Merge tag 'kvm-s390-next-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Features and Enhancements for 5.7 part1

1. Allow to disable gisa
2. protected virtual machines
  Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's
  state like guest memory and guest registers anymore. Instead the
  PVMs are mostly managed by a new entity called Ultravisor (UV),
  which provides an API, so KVM and the PV can request management
  actions.

  PVMs are encrypted at rest and protected from hypervisor access
  while running.  They switch from a normal operation into protected
  mode, so we can still use the standard boot process to load a
  encrypted blob and then move it into protected mode.

  Rebooting is only possible by passing through the unprotected/normal
  mode and switching to protected again.

  One mm related patch will go via Andrews mm tree ( mm/gup/writeback:
  add callbacks for inaccessible pages)
2020-03-16 18:19:34 +01:00
Vitaly Kuznetsov
6d05a965ad KVM: selftests: enlightened VMPTRLD with an incorrect GPA
Check that guest doesn't hang when an invalid eVMCS GPA is specified.
Testing that #UD is injected would probably be better but selftests lack
the infrastructure currently.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 18:19:32 +01:00
Vitaly Kuznetsov
41b0552aa6 KVM: selftests: test enlightened vmenter with wrong eVMCS version
Check that VMfailInvalid happens when eVMCS revision is is invalid.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 18:19:32 +01:00
Vitaly Kuznetsov
7bcf732e74 KVM: selftests: define and use EVMCS_VERSION
KVM allows to use revision_id from MSR_IA32_VMX_BASIC as eVMCS revision_id
to workaround a bug in genuine Hyper-V (see the comment in
nested_vmx_handle_enlightened_vmptrld()), this shouldn't be used by
default. Switch to using KVM_EVMCS_VERSION(1).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 18:19:31 +01:00
Vitaly Kuznetsov
b6a0653ae2 KVM: nVMX: properly handle errors in nested_vmx_handle_enlightened_vmptrld()
nested_vmx_handle_enlightened_vmptrld() fails in two cases:
- when we fail to kvm_vcpu_map() the supplied GPA
- when revision_id is incorrect.
Genuine Hyper-V raises #UD in the former case (at least with *some*
incorrect GPAs) and does VMfailInvalid() in the later. KVM doesn't do
anything so L1 just gets stuck retrying the same faulty VMLAUNCH.

nested_vmx_handle_enlightened_vmptrld() has two call sites:
nested_vmx_run() and nested_get_vmcs12_pages(). The former needs to queue
do much: the failure there happens after migration when L2 was running (and
L1 did something weird like wrote to VP assist page from a different vCPU),
just kill L1 with KVM_EXIT_INTERNAL_ERROR.

Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
[Squash kbuild autopatch. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 18:19:30 +01:00
Vitaly Kuznetsov
e942dbf8c5 KVM: nVMX: stop abusing need_vmcs12_to_shadow_sync for eVMCS mapping
When vmx_set_nested_state() happens, we may not have all the required
data to map enlightened VMCS: e.g. HV_X64_MSR_VP_ASSIST_PAGE MSR may not
yet be restored so we need a postponed action. Currently, we (ab)use
need_vmcs12_to_shadow_sync/nested_sync_vmcs12_to_shadow() for that but
this is not ideal:
- We may not need to sync anything if L2 is running
- It is hard to propagate errors from nested_sync_vmcs12_to_shadow()
 as we call it from vmx_prepare_switch_to_guest() which happens just
 before we do VMLAUNCH, the code is not ready to handle errors there.

Move eVMCS mapping to nested_get_vmcs12_pages() and request
KVM_REQ_GET_VMCS12_PAGES, it seems to be is less abusive in nature.
It would probably be possible to introduce a specialized KVM_REQ_EVMCS_MAP
but it is undesirable to propagate eVMCS specifics all the way up to x86.c

Note, we don't need to request KVM_REQ_GET_VMCS12_PAGES from
vmx_set_nested_state() directly as nested_vmx_enter_non_root_mode() already
does that. Requesting KVM_REQ_GET_VMCS12_PAGES is done to document the
(non-obvious) side-effect and to be future proof.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 18:19:29 +01:00
Paolo Bonzini
0c546725ee Merge branch 'kvm-null-pointer-fix' into HEAD 2020-03-16 17:59:11 +01:00
Wainer dos Santos Moschetta
352be2c539 selftests: kvm: Uses TEST_FAIL in tests/utilities
Changed all tests and utilities to use TEST_FAIL macro
instead of TEST_ASSERT(false,...).

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:11 +01:00
Wainer dos Santos Moschetta
a46f8a63cd selftests: kvm: Introduce the TEST_FAIL macro
Some tests/utilities use the TEST_ASSERT(false, ...) pattern to
indicate a failure and stop execution.

This change introduces the TEST_FAIL macro which is a wrap around
TEST_ASSERT(false, ...) and so provides a direct alternative for
failing a test.

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:10 +01:00
Christian Borntraeger
3203a01737 selftests: KVM: s390: check for registers to NOT change on reset
Normal reset and initial CPU reset do not clear all registers. Add a
test that those registers are NOT changed.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:09 +01:00
Christian Borntraeger
b0435a12a6 selftests: KVM: s390: test more register variants for the reset ioctl
We should not only test the oneregs or the get_(x)regs interfaces but
also the sync_regs. Those are usually the canonical place for register
content.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:08 +01:00
Christian Borntraeger
41cbed5b07 selftests: KVM: s390: fix early guest crash
The guest crashes very early due to changes in the control registers
used by dynamic address translation. Let us use different registers
that will not crash the guest.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:07 +01:00
Andrew Jones
94c4b76b88 KVM: selftests: Introduce steal-time test
The steal-time test confirms what is reported to the guest as stolen
time is consistent with the run_delay reported for the VCPU thread
on the host. Both x86_64 and AArch64 have the concept of steal/stolen
time so this test is introduced for both architectures.

While adding the test we ensure .gitignore has all tests listed
(it was missing s390x/resets) and that the Makefile has all tests
listed in alphabetical order (not really necessary, but it almost
was already...). We also extend the common API with a new num-guest-
pages call and a new timespec call.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:07 +01:00
Andrew Jones
beca54702d KVM: selftests: virt_map should take npages, not size
Also correct the comment and prototype for vm_create_default(),
as it takes a number of pages, not a size.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:06 +01:00
Andrew Jones
d0aac3320d KVM: selftests: Use consistent message for test skipping
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:05 +01:00
Andrew Jones
d9eaf19ecc KVM: selftests: Enable printf format warnings for TEST_ASSERT
Use the format attribute to enable printf format warnings, and
then fix them all.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:04 +01:00
Christian Borntraeger
6a46fcf92f selftests: KVM: s390: fix format strings for access reg test
acrs are 32 bit and not 64 bit.

Reported-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:03 +01:00
Christian Borntraeger
53362fe930 selftests: KVM: s390: fixup fprintf format error in reset.c
value is u64 and not string.

Reported-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:03 +01:00
Andrew Jones
425936246f KVM: selftests: Share common API documentation
Move function documentation comment blocks to the header files in
order to avoid duplicating them for each architecture. While at
it clean up and fix up the comment blocks.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:02 +01:00
Andrew Jones
1914f624f5 selftests: KVM: SVM: Add vmcall test to gitignore
Add svm_vmcall_test to gitignore list, and realphabetize it.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:01 +01:00
Miaohe Lin
0b66465344 KVM: nSVM: Remove an obsolete comment.
The function does not return bool anymore.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:59:00 +01:00
Paolo Bonzini
8e205a6b2a KVM: X86: correct meaningless kvm_apicv_activated() check
After test_and_set_bit() for kvm->arch.apicv_inhibit_reasons, we will
always get false when calling kvm_apicv_activated() because it's sure
apicv_inhibit_reasons do not equal to 0.

What the code wants to do, is check whether APICv was *already* active
and if so skip the costly request; we can do this using cmpxchg.

Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:59 +01:00
Oliver Upton
212617dbb6 KVM: nVMX: Consolidate nested MTF checks to helper function
commit 5ef8acbdd6 ("KVM: nVMX: Emulate MTF when performing
instruction emulation") introduced a helper to check the MTF
VM-execution control in vmcs12. Change pre-existing check in
nested_vmx_exit_reflected() to instead use the helper.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:59 +01:00
Wanpeng Li
041bc42ce2 KVM: VMX: Micro-optimize vmexit time when not exposing PMU
PMU is not exposed to guest by most of products from cloud providers since the
bad performance of PMU emulation and security concern. However, it calls
perf_guest_switch_get_msrs() and clear_atomic_switch_msr() unconditionally
even if PMU is not exposed to the guest before each vmentry.

~2% vmexit time reduced can be observed by kvm-unit-tests/vmexit.flat on my
SKX server.

Before patch:
vmcall 1559

After patch:
vmcall 1529

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:58 +01:00
Andrew Jones
331b4de9a7 KVM: selftests: s390x: Provide additional num-guest-pages adjustment
s390 requires 1M aligned guest sizes. Embedding the rounding in
vm_adjust_num_guest_pages() allows us to remove it from a few
other places.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:57 +01:00
Suravee Suthikulpanit
ab56f8e62d kvm: svm: Introduce GA Log tracepoint for AVIC
GA Log tracepoint is useful when debugging AVIC performance
issue as it can be used with perf to count the number of times
IOMMU AVIC injects interrupts through the slow-path instead of
directly inject interrupts to the target vcpu.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:56 +01:00
Peter Xu
3ac40c404c KVM: Documentation: Update fast page fault for indirect sp
Clarify locking.rst to mention early that we're not enabling fast page
fault for indirect sps.  The previous wording is confusing, in that it
seems the proposed solution has been already implemented but it has not.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:56 +01:00
Paolo Bonzini
78f2145c4d KVM: nSVM: avoid loss of pending IRQ/NMI before entering L2
This patch reproduces for nSVM the change that was made for nVMX in
commit b5861e5cf2 ("KVM: nVMX: Fix loss of pending IRQ/NMI before
entering L2").  While I do not have a test that breaks without it, I
cannot see why it would not be necessary since all events are unblocked
by VMRUN's setting of GIF back to 1.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:55 +01:00
Paolo Bonzini
b518ba9fa6 KVM: nSVM: implement check_nested_events for interrupts
The current implementation of physical interrupt delivery to a nested guest
is quite broken.  It relies on svm_interrupt_allowed returning false if
VINTR=1 so that the interrupt can be injected from enable_irq_window,
but this does not work for guests that do not intercept HLT or that rely
on clearing the host IF to block physical interrupts while L2 runs.

This patch can be split in two logical parts, but including only
one breaks tests so I am combining both changes together.

The first and easiest is simply to return true for svm_interrupt_allowed
if HF_VINTR_MASK is set and HIF is set.  This way the semantics of
svm_interrupt_allowed are respected: svm_interrupt_allowed being false
does not mean "call enable_irq_window", it means "interrupts cannot
be injected now".

After doing this, however, we need another place to inject the
interrupt, and fortunately we already have one, check_nested_events,
which nested SVM does not implement but which is meant exactly for this
purpose.  It is called before interrupts are injected, and it can
therefore do the L2->L1 switch while leaving inject_pending_event
none the wiser.

This patch was developed together with Cathy Avery, who wrote the
test and did a lot of the initial debugging.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:54 +01:00
Paolo Bonzini
64b5bd2704 KVM: nSVM: ignore L1 interrupt window while running L2 with V_INTR_MASKING=1
If a nested VM is started while an IRQ was pending and with
V_INTR_MASKING=1, the behavior of the guest depends on host IF.  If it
is 1, the VM should exit immediately, before executing the first
instruction of the guest, because VMRUN sets GIF back to 1.

If it is 0 and the host has VGIF, however, at the time of the VMRUN
instruction L0 is running the guest with a pending interrupt window
request.  This interrupt window request is completely irrelevant to
L2, since IF only controls virtual interrupts, so this patch drops
INTERCEPT_VINTR from the VMCB while running L2 under these circumstances.
To simplify the code, both steps of enabling the interrupt window
(setting the VINTR intercept and requesting a fake virtual interrupt
in svm_inject_irq) are grouped in the svm_set_vintr function, and
likewise for dismissing the interrupt window request in svm_clear_vintr.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:53 +01:00
Paolo Bonzini
b5ec2e020b KVM: nSVM: do not change host intercepts while nested VM is running
Instead of touching the host intercepts so that the bitwise OR in
recalc_intercepts just works, mask away uninteresting intercepts
directly in recalc_intercepts.

This is cleaner and keeps the logic in one place even for intercepts
that can change even while L2 is running.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:53 +01:00