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| author | Like Xu <like.xu@linux.intel.com> | 2021-02-01 08:10:36 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 13:27:25 +0300 |
| commit | e6209a3bef793e8fe29c873a7612023916eaa611 (patch) | |
| tree | b885d145d233977d0b6e5105d5194d5a5a6ad3ab /arch/x86/kvm/vmx/vmx.c | |
| parent | 9254beaafd12e27d48149fab3b16db372bc90ad7 (diff) | |
| download | linux-e6209a3bef793e8fe29c873a7612023916eaa611.tar.xz | |
KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI
The current vPMU only supports Architecture Version 2. According to
Intel SDM "17.4.7 Freezing LBR and Performance Counters on PMI", if
IA32_DEBUGCTL.Freeze_LBR_On_PMI = 1, the LBR is frozen on the virtual
PMI and the KVM would emulate to clear the LBR bit (bit 0) in
IA32_DEBUGCTL. Also, guest needs to re-enable IA32_DEBUGCTL.LBR
to resume recording branches.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Message-Id: <20210201051039.255478-9-like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index e2f8c3c68f02..9169c700874e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1963,7 +1963,7 @@ static u64 vcpu_supported_debugctl(struct kvm_vcpu *vcpu) u64 debugctl = vmx_supported_debugctl(); if (!intel_pmu_lbr_is_enabled(vcpu)) - debugctl &= ~DEBUGCTLMSR_LBR; + debugctl &= ~DEBUGCTLMSR_LBR_MASK; return debugctl; } |