When the PMU is disabled, don't bother sharing the PMU MSRs with userspace through KVM_GET_MSR_INDEX_LIST. Instead, filter them out so userspace doesn't have to keep track of them. Note that 'enable_pmu' is read-only, so userspace has no control over whether the PMU MSRs are included in the list or not. Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 521b433f978c..19bc42a6946d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7042,13 +7042,20 @@ static void kvm_init_msr_list(void) continue; break; case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17: - if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >= - min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) + if ((msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >= + min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) || + !enable_pmu) continue; break; case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17: - if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >= - min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) + if ((msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >= + min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) || + !enable_pmu) + continue; + break; + case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5: + case MSR_K7_EVNTSEL0 ... MSR_K7_PERFCTR3: + if (!enable_pmu) continue; break; case MSR_IA32_XFD: -- 2.38.1.431.g37b22c650d-goog
