KVM: x86: Intel PERF_CAPABILITIES fix and cleanups

[PATCH 0/3] KVM: x86: Intel PERF_CAPABILITIES fix and cleanups

Sean Christopherson posted 3 patches 3 years, 8 months ago

Download series mbox

arch/x86/kvm/vmx/pmu_intel.c | 12 +++---------
arch/x86/kvm/vmx/vmx.h       | 29 ++++++++++++++++++++---------
arch/x86/kvm/x86.c           |  4 ++--
3 files changed, 25 insertions(+), 20 deletions(-)

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[PATCH 0/3] KVM: x86: Intel PERF_CAPABILITIES fix and cleanups

Posted by Sean Christopherson 3 years, 8 months ago

Fix a bug where KVM doesn't refresh the vPMU after userspace writes
PERF_CAPABILITIES, and then leverage that fix to avoiding checking
guest_cpuid_has(X86_FEATURE_PDCM) during VM-Enter, which is slow enough
that it shows up in perf traces[*].

[*] https://gist.github.com/avagin/f50a6d569440c9ae382281448c187f4e

Sean Christopherson (3):
  KVM: x86: Refresh PMU after writes to MSR_IA32_PERF_CAPABILITIES
  KVM: VMX: Use proper type-safe functions for vCPU => LBRs helpers
  KVM: VMX: Adjust number of LBR records for PERF_CAPABILITIES at
    refresh

 arch/x86/kvm/vmx/pmu_intel.c | 12 +++---------
 arch/x86/kvm/vmx/vmx.h       | 29 ++++++++++++++++++++---------
 arch/x86/kvm/x86.c           |  4 ++--
 3 files changed, 25 insertions(+), 20 deletions(-)


base-commit: 1a4d88a361af4f2e91861d632c6a1fe87a9665c2
-- 
2.37.1.359.gd136c6c3e2-goog

Re: [PATCH 0/3] KVM: x86: Intel PERF_CAPABILITIES fix and cleanups

Posted by Paolo Bonzini 3 years, 8 months ago

Queued, thanks.  The patches have been out for almost two weeks and,
based on the thread, any other cleanups/fixes can be one on top
(particularly the feature MSR one).

Paolo