diff options
| author | Eric Hankland <ehankland@google.com> | 2020-01-27 13:22:56 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-02-05 16:01:15 +0100 |
| commit | 4400cf546b4bb62d49198f6642add01bf6e9b34d (patch) | |
| tree | 7dc14820cd501a5bd7f6c0b463545a8f591148e5 /arch/x86/kvm | |
| parent | a83502314ce303c6341b249c41121759c7477ba1 (diff) | |
KVM: x86: Fix perfctr WRMSR for running counters
Correct the logic in intel_pmu_set_msr() for fixed and general purpose
counters. This was recently changed to set pmc->counter without taking
in to account the value of pmc_read_counter() which will be incorrect if
the counter is currently running and non-zero; this changes back to the
old logic which accounted for the value of currently running counters.
Signed-off-by: Eric Hankland <ehankland@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 34a3a17bb6d7..fd21cdb10b79 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -260,13 +260,12 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; default: if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) { - if (msr_info->host_initiated) - pmc->counter = data; - else - pmc->counter = (s32)data; + if (!msr_info->host_initiated) + data = (s64)(s32)data; + pmc->counter += data - pmc_read_counter(pmc); return 0; } else if ((pmc = get_fixed_pmc(pmu, msr))) { - pmc->counter = data; + pmc->counter += data - pmc_read_counter(pmc); return 0; } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { if (data == pmc->eventsel) |