diff options
| author | Eric Hankland <ehankland@google.com> | 2020-02-21 18:34:13 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 17:57:30 +0100 |
| commit | 168d918f2643d7d3f0240e768d40b4f8aba3540a (patch) | |
| tree | 1279f78c5f7baa15856fbfe9fd87ca7def67c28a /arch/x86 | |
| parent | 7f42aa76d4a5587939ee98d541ea1b97b382f408 (diff) | |
KVM: x86: Adjust counter sample period after a wrmsr
The sample_period of a counter tracks when that counter will
overflow and set global status/trigger a PMI. However this currently
only gets set when the initial counter is created or when a counter is
resumed; this updates the sample period after a wrmsr so running
counters will accurately reflect their new value.
Signed-off-by: Eric Hankland <ehankland@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/pmu.h | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 6 |
3 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index bcc6a73d6628..d1f8ca57d354 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -111,7 +111,7 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, .config = config, }; - attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc); + attr.sample_period = get_sample_period(pmc, pmc->counter); if (in_tx) attr.config |= HSW_IN_TX; @@ -158,7 +158,7 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc) /* recalibrate sample period and check if it's accepted by perf core */ if (perf_event_period(pmc->perf_event, - (-pmc->counter) & pmc_bitmask(pmc))) + get_sample_period(pmc, pmc->counter))) return false; /* reuse perf_event to serve as pmc_reprogram_counter() does*/ diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index 13332984b6d5..d7da2b9e0755 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -129,6 +129,15 @@ static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr) return NULL; } +static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value) +{ + u64 sample_period = (-counter_value) & pmc_bitmask(pmc); + + if (!sample_period) + sample_period = pmc_bitmask(pmc) + 1; + return sample_period; +} + void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel); void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int fixed_idx); void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx); diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index fd21cdb10b79..e933541751fb 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -263,9 +263,15 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated) data = (s64)(s32)data; pmc->counter += data - pmc_read_counter(pmc); + if (pmc->perf_event) + perf_event_period(pmc->perf_event, + get_sample_period(pmc, data)); return 0; } else if ((pmc = get_fixed_pmc(pmu, msr))) { pmc->counter += data - pmc_read_counter(pmc); + if (pmc->perf_event) + perf_event_period(pmc->perf_event, + get_sample_period(pmc, data)); return 0; } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { if (data == pmc->eventsel) |