diff options
Diffstat (limited to 'virt/kvm/arm')
| -rw-r--r-- | virt/kvm/arm/pmu.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index f8dc17430813..591a11d1bd13 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -62,6 +62,27 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx); } +/** + * kvm_pmu_stop_counter - stop PMU counter + * @pmc: The PMU counter pointer + * + * If this counter has been configured to monitor some event, release it here. + */ +static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc) +{ + u64 counter, reg; + + if (pmc->perf_event) { + counter = kvm_pmu_get_counter_value(vcpu, pmc->idx); + reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx; + vcpu_sys_reg(vcpu, reg) = counter; + perf_event_disable(pmc->perf_event); + perf_event_release_kernel(pmc->perf_event); + pmc->perf_event = NULL; + } +} + u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu) { u64 val = vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMU_PMCR_N_SHIFT; @@ -127,3 +148,56 @@ void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val) perf_event_disable(pmc->perf_event); } } + +static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) +{ + return (vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) && + (vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & BIT(select_idx)); +} + +/** + * kvm_pmu_set_counter_event_type - set selected counter to monitor some event + * @vcpu: The vcpu pointer + * @data: The data guest writes to PMXEVTYPER_EL0 + * @select_idx: The number of selected counter + * + * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an + * event with given hardware event number. Here we call perf_event API to + * emulate this action and create a kernel perf event for it. + */ +void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, + u64 select_idx) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc = &pmu->pmc[select_idx]; + struct perf_event *event; + struct perf_event_attr attr; + u64 eventsel, counter; + + kvm_pmu_stop_counter(vcpu, pmc); + eventsel = data & ARMV8_PMU_EVTYPE_EVENT; + + memset(&attr, 0, sizeof(struct perf_event_attr)); + attr.type = PERF_TYPE_RAW; + attr.size = sizeof(attr); + attr.pinned = 1; + attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, select_idx); + attr.exclude_user = data & ARMV8_PMU_EXCLUDE_EL0 ? 1 : 0; + attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0; + attr.exclude_hv = 1; /* Don't count EL2 events */ + attr.exclude_host = 1; /* Don't count host events */ + attr.config = eventsel; + + counter = kvm_pmu_get_counter_value(vcpu, select_idx); + /* The initial sample period (overflow count) of an event. */ + attr.sample_period = (-counter) & pmc->bitmask; + + event = perf_event_create_kernel_counter(&attr, -1, current, NULL, pmc); + if (IS_ERR(event)) { + pr_err_once("kvm: pmu event creation failed %ld\n", + PTR_ERR(event)); + return; + } + + pmc->perf_event = event; +} |