diff options
| author | Aaron Lewis <aaronlewis@google.com> | 2023-03-07 15:13:56 +0100 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-04-07 18:24:16 +0200 |
| commit | dfdeda67ea2dac57d2d7506d65cfe5a0878ad285 (patch) | |
| tree | cf88035aea3e9860e1cca9e3d500c345776e7185 /arch/x86 | |
| parent | KVM: x86/pmu: Fix a typo in kvm_pmu_request_counter_reprogam() (diff) | |
| download | linux-dfdeda67ea2dac57d2d7506d65cfe5a0878ad285.tar.xz linux-dfdeda67ea2dac57d2d7506d65cfe5a0878ad285.zip | |
KVM: x86/pmu: Prevent the PMU from counting disallowed events
When counting "Instructions Retired" (0xc0) in a guest, KVM will
occasionally increment the PMU counter regardless of if that event is
being filtered. This is because some PMU events are incremented via
kvm_pmu_trigger_event(), which doesn't know about the event filter. Add
the event filter to kvm_pmu_trigger_event(), so events that are
disallowed do not increment their counters.
Fixes: 9cd803d496e7 ("KVM: x86: Update vPMCs when retiring instructions")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230307141400.1486314-2-aaronlewis@google.com
[sean: prepend "pmc" to the new function]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 2226db9601e2..597a8f8f90b9 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -400,6 +400,12 @@ static bool check_pmu_event_filter(struct kvm_pmc *pmc) return is_fixed_event_allowed(filter, pmc->idx); } +static bool pmc_event_is_allowed(struct kvm_pmc *pmc) +{ + return pmc_is_globally_enabled(pmc) && pmc_speculative_in_use(pmc) && + check_pmu_event_filter(pmc); +} + static void reprogram_counter(struct kvm_pmc *pmc) { struct kvm_pmu *pmu = pmc_to_pmu(pmc); @@ -409,10 +415,7 @@ static void reprogram_counter(struct kvm_pmc *pmc) pmc_pause_counter(pmc); - if (!pmc_speculative_in_use(pmc) || !pmc_is_globally_enabled(pmc)) - goto reprogram_complete; - - if (!check_pmu_event_filter(pmc)) + if (!pmc_event_is_allowed(pmc)) goto reprogram_complete; if (pmc->counter < pmc->prev_counter) @@ -688,7 +691,7 @@ void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id) for_each_set_bit(i, pmu->all_valid_pmc_idx, X86_PMC_IDX_MAX) { pmc = static_call(kvm_x86_pmu_pmc_idx_to_pmc)(pmu, i); - if (!pmc || !pmc_is_globally_enabled(pmc) || !pmc_speculative_in_use(pmc)) + if (!pmc || !pmc_event_is_allowed(pmc)) continue; /* Ignore checks for edge detect, pin control, invert and CMASK bits */ |