diff options
Diffstat (limited to 'arch/x86/kvm/pmu.c')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 173 |
1 files changed, 139 insertions, 34 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 75e9cfc689f8..40ac4cb44ed2 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -26,11 +26,18 @@ /* This is enough to filter the vast majority of currently defined events. */ #define KVM_PMU_EVENT_FILTER_MAX_EVENTS 300 +/* Unadultered PMU capabilities of the host, i.e. of hardware. */ +static struct x86_pmu_capability __read_mostly kvm_host_pmu; + +/* KVM's PMU capabilities, i.e. the intersection of KVM and hardware support. */ struct x86_pmu_capability __read_mostly kvm_pmu_cap; -EXPORT_SYMBOL_GPL(kvm_pmu_cap); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_cap); -struct kvm_pmu_emulated_event_selectors __read_mostly kvm_pmu_eventsel; -EXPORT_SYMBOL_GPL(kvm_pmu_eventsel); +struct kvm_pmu_emulated_event_selectors { + u64 INSTRUCTIONS_RETIRED; + u64 BRANCH_INSTRUCTIONS_RETIRED; +}; +static struct kvm_pmu_emulated_event_selectors __read_mostly kvm_pmu_eventsel; /* Precise Distribution of Instructions Retired (PDIR) */ static const struct x86_cpu_id vmx_pebs_pdir_cpu[] = { @@ -96,6 +103,54 @@ void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops) #undef __KVM_X86_PMU_OP } +void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops) +{ + bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL; + int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS; + + perf_get_x86_pmu_capability(&kvm_host_pmu); + + /* + * Hybrid PMUs don't play nice with virtualization without careful + * configuration by userspace, and KVM's APIs for reporting supported + * vPMU features do not account for hybrid PMUs. Disable vPMU support + * for hybrid PMUs until KVM gains a way to let userspace opt-in. + */ + if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) + enable_pmu = false; + + if (enable_pmu) { + /* + * WARN if perf did NOT disable hardware PMU if the number of + * architecturally required GP counters aren't present, i.e. if + * there are a non-zero number of counters, but fewer than what + * is architecturally required. + */ + if (!kvm_host_pmu.num_counters_gp || + WARN_ON_ONCE(kvm_host_pmu.num_counters_gp < min_nr_gp_ctrs)) + enable_pmu = false; + else if (is_intel && !kvm_host_pmu.version) + enable_pmu = false; + } + + if (!enable_pmu) { + memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap)); + return; + } + + memcpy(&kvm_pmu_cap, &kvm_host_pmu, sizeof(kvm_host_pmu)); + kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2); + kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp, + pmu_ops->MAX_NR_GP_COUNTERS); + kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed, + KVM_MAX_NR_FIXED_COUNTERS); + + kvm_pmu_eventsel.INSTRUCTIONS_RETIRED = + perf_get_hw_event_config(PERF_COUNT_HW_INSTRUCTIONS); + kvm_pmu_eventsel.BRANCH_INSTRUCTIONS_RETIRED = + perf_get_hw_event_config(PERF_COUNT_HW_BRANCH_INSTRUCTIONS); +} + static inline void __kvm_perf_overflow(struct kvm_pmc *pmc, bool in_pmi) { struct kvm_pmu *pmu = pmc_to_pmu(pmc); @@ -318,7 +373,7 @@ void pmc_write_counter(struct kvm_pmc *pmc, u64 val) pmc->counter &= pmc_bitmask(pmc); pmc_update_sample_period(pmc); } -EXPORT_SYMBOL_GPL(pmc_write_counter); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(pmc_write_counter); static int filter_cmp(const void *pa, const void *pb, u64 mask) { @@ -426,7 +481,7 @@ static bool is_fixed_event_allowed(struct kvm_x86_pmu_event_filter *filter, return true; } -static bool check_pmu_event_filter(struct kvm_pmc *pmc) +static bool pmc_is_event_allowed(struct kvm_pmc *pmc) { struct kvm_x86_pmu_event_filter *filter; struct kvm *kvm = pmc->vcpu->kvm; @@ -441,12 +496,6 @@ 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 int reprogram_counter(struct kvm_pmc *pmc) { struct kvm_pmu *pmu = pmc_to_pmu(pmc); @@ -457,7 +506,8 @@ static int reprogram_counter(struct kvm_pmc *pmc) emulate_overflow = pmc_pause_counter(pmc); - if (!pmc_event_is_allowed(pmc)) + if (!pmc_is_globally_enabled(pmc) || !pmc_is_locally_enabled(pmc) || + !pmc_is_event_allowed(pmc)) return 0; if (emulate_overflow) @@ -492,6 +542,47 @@ static int reprogram_counter(struct kvm_pmc *pmc) eventsel & ARCH_PERFMON_EVENTSEL_INT); } +static bool pmc_is_event_match(struct kvm_pmc *pmc, u64 eventsel) +{ + /* + * Ignore checks for edge detect (all events currently emulated by KVM + * are always rising edges), pin control (unsupported by modern CPUs), + * and counter mask and its invert flag (KVM doesn't emulate multiple + * events in a single clock cycle). + * + * Note, the uppermost nibble of AMD's mask overlaps Intel's IN_TX (bit + * 32) and IN_TXCP (bit 33), as well as two reserved bits (bits 35:34). + * Checking the "in HLE/RTM transaction" flags is correct as the vCPU + * can't be in a transaction if KVM is emulating an instruction. + * + * Checking the reserved bits might be wrong if they are defined in the + * future, but so could ignoring them, so do the simple thing for now. + */ + return !((pmc->eventsel ^ eventsel) & AMD64_RAW_EVENT_MASK_NB); +} + +void kvm_pmu_recalc_pmc_emulation(struct kvm_pmu *pmu, struct kvm_pmc *pmc) +{ + bitmap_clear(pmu->pmc_counting_instructions, pmc->idx, 1); + bitmap_clear(pmu->pmc_counting_branches, pmc->idx, 1); + + /* + * Do NOT consult the PMU event filters, as the filters must be checked + * at the time of emulation to ensure KVM uses fresh information, e.g. + * omitting a PMC from a bitmap could result in a missed event if the + * filter is changed to allow counting the event. + */ + if (!pmc_is_locally_enabled(pmc)) + return; + + if (pmc_is_event_match(pmc, kvm_pmu_eventsel.INSTRUCTIONS_RETIRED)) + bitmap_set(pmu->pmc_counting_instructions, pmc->idx, 1); + + if (pmc_is_event_match(pmc, kvm_pmu_eventsel.BRANCH_INSTRUCTIONS_RETIRED)) + bitmap_set(pmu->pmc_counting_branches, pmc->idx, 1); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_recalc_pmc_emulation); + void kvm_pmu_handle_event(struct kvm_vcpu *vcpu) { DECLARE_BITMAP(bitmap, X86_PMC_IDX_MAX); @@ -527,6 +618,9 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu) */ if (unlikely(pmu->need_cleanup)) kvm_pmu_cleanup(vcpu); + + kvm_for_each_pmc(pmu, pmc, bit, bitmap) + kvm_pmu_recalc_pmc_emulation(pmu, pmc); } int kvm_pmu_check_rdpmc_early(struct kvm_vcpu *vcpu, unsigned int idx) @@ -650,6 +744,7 @@ int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = pmu->global_ctrl; break; case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: case MSR_CORE_PERF_GLOBAL_OVF_CTRL: msr_info->data = 0; break; @@ -711,6 +806,10 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated) pmu->global_status &= ~data; break; + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: + if (!msr_info->host_initiated) + pmu->global_status |= data & ~pmu->global_status_rsvd; + break; default: kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index); return kvm_pmu_call(set_msr)(vcpu, msr_info); @@ -789,6 +888,10 @@ void kvm_pmu_refresh(struct kvm_vcpu *vcpu) */ if (kvm_pmu_has_perf_global_ctrl(pmu) && pmu->nr_arch_gp_counters) pmu->global_ctrl = GENMASK_ULL(pmu->nr_arch_gp_counters - 1, 0); + + bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters); + bitmap_set(pmu->all_valid_pmc_idx, KVM_FIXED_PMC_BASE_IDX, + pmu->nr_arch_fixed_counters); } void kvm_pmu_init(struct kvm_vcpu *vcpu) @@ -813,7 +916,7 @@ void kvm_pmu_cleanup(struct kvm_vcpu *vcpu) pmu->pmc_in_use, X86_PMC_IDX_MAX); kvm_for_each_pmc(pmu, pmc, i, bitmask) { - if (pmc->perf_event && !pmc_speculative_in_use(pmc)) + if (pmc->perf_event && !pmc_is_locally_enabled(pmc)) pmc_stop_counter(pmc); } @@ -860,44 +963,46 @@ static inline bool cpl_is_matched(struct kvm_pmc *pmc) select_user; } -void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 eventsel) +static void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, + const unsigned long *event_pmcs) { DECLARE_BITMAP(bitmap, X86_PMC_IDX_MAX); struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); struct kvm_pmc *pmc; - int i; + int i, idx; BUILD_BUG_ON(sizeof(pmu->global_ctrl) * BITS_PER_BYTE != X86_PMC_IDX_MAX); + if (bitmap_empty(event_pmcs, X86_PMC_IDX_MAX)) + return; + if (!kvm_pmu_has_perf_global_ctrl(pmu)) - bitmap_copy(bitmap, pmu->all_valid_pmc_idx, X86_PMC_IDX_MAX); - else if (!bitmap_and(bitmap, pmu->all_valid_pmc_idx, + bitmap_copy(bitmap, event_pmcs, X86_PMC_IDX_MAX); + else if (!bitmap_and(bitmap, event_pmcs, (unsigned long *)&pmu->global_ctrl, X86_PMC_IDX_MAX)) return; + idx = srcu_read_lock(&vcpu->kvm->srcu); kvm_for_each_pmc(pmu, pmc, i, bitmap) { - /* - * Ignore checks for edge detect (all events currently emulated - * but KVM are always rising edges), pin control (unsupported - * by modern CPUs), and counter mask and its invert flag (KVM - * doesn't emulate multiple events in a single clock cycle). - * - * Note, the uppermost nibble of AMD's mask overlaps Intel's - * IN_TX (bit 32) and IN_TXCP (bit 33), as well as two reserved - * bits (bits 35:34). Checking the "in HLE/RTM transaction" - * flags is correct as the vCPU can't be in a transaction if - * KVM is emulating an instruction. Checking the reserved bits - * might be wrong if they are defined in the future, but so - * could ignoring them, so do the simple thing for now. - */ - if (((pmc->eventsel ^ eventsel) & AMD64_RAW_EVENT_MASK_NB) || - !pmc_event_is_allowed(pmc) || !cpl_is_matched(pmc)) + if (!pmc_is_event_allowed(pmc) || !cpl_is_matched(pmc)) continue; kvm_pmu_incr_counter(pmc); } + srcu_read_unlock(&vcpu->kvm->srcu, idx); +} + +void kvm_pmu_instruction_retired(struct kvm_vcpu *vcpu) +{ + kvm_pmu_trigger_event(vcpu, vcpu_to_pmu(vcpu)->pmc_counting_instructions); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_instruction_retired); + +void kvm_pmu_branch_retired(struct kvm_vcpu *vcpu) +{ + kvm_pmu_trigger_event(vcpu, vcpu_to_pmu(vcpu)->pmc_counting_branches); } -EXPORT_SYMBOL_GPL(kvm_pmu_trigger_event); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_branch_retired); static bool is_masked_filter_valid(const struct kvm_x86_pmu_event_filter *filter) { |