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| author | Like Xu <likexu@tencent.com> | 2023-04-04 15:17:59 +0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-04-05 16:33:10 -0700 |
| commit | 7e768ce8278bafe43e2a4771a82b61856190a3fc (patch) | |
| tree | 1e9e1aadaf35e5abd21be169900724e488035c42 /arch/x86/kvm/pmu.c | |
| parent | 12aad9164763bb4890277d3b2a4664f443a48e3f (diff) | |
| download | lwn-7e768ce8278bafe43e2a4771a82b61856190a3fc.tar.gz lwn-7e768ce8278bafe43e2a4771a82b61856190a3fc.zip | |
KVM: x86/pmu: Zero out pmu->all_valid_pmc_idx each time it's refreshed
The kvm_pmu_refresh() may be called repeatedly (e.g. configure guest
CPUID repeatedly or update MSR_IA32_PERF_CAPABILITIES) and each
call will use the last pmu->all_valid_pmc_idx value, with the residual
bits introducing additional overhead later in the vPMU emulation.
Fixes: b35e5548b411 ("KVM: x86/vPMU: Add lazy mechanism to release perf_event per vPMC")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230404071759.75376-1-likexu@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/pmu.c')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 612e6c70ce2e..29492c2a0c82 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -589,6 +589,7 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) */ void kvm_pmu_refresh(struct kvm_vcpu *vcpu) { + bitmap_zero(vcpu_to_pmu(vcpu)->all_valid_pmc_idx, X86_PMC_IDX_MAX); static_call(kvm_x86_pmu_refresh)(vcpu); } |