diff options
Diffstat (limited to 'arch/x86/kvm/pmu.h')
| -rw-r--r-- | arch/x86/kvm/pmu.h | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h new file mode 100644 index 0000000000..a46aa9b251 --- /dev/null +++ b/arch/x86/kvm/pmu.h @@ -0,0 +1,257 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __KVM_X86_PMU_H +#define __KVM_X86_PMU_H + +#include <linux/nospec.h> + +#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu) +#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu)) +#define pmc_to_pmu(pmc) (&(pmc)->vcpu->arch.pmu) + +#define MSR_IA32_MISC_ENABLE_PMU_RO_MASK (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL | \ + MSR_IA32_MISC_ENABLE_BTS_UNAVAIL) + +/* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */ +#define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf) + +#define VMWARE_BACKDOOR_PMC_HOST_TSC 0x10000 +#define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001 +#define VMWARE_BACKDOOR_PMC_APPARENT_TIME 0x10002 + +struct kvm_pmu_ops { + bool (*hw_event_available)(struct kvm_pmc *pmc); + struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx); + struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu, + unsigned int idx, u64 *mask); + struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, u32 msr); + bool (*is_valid_rdpmc_ecx)(struct kvm_vcpu *vcpu, unsigned int idx); + bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr); + int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info); + int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info); + void (*refresh)(struct kvm_vcpu *vcpu); + void (*init)(struct kvm_vcpu *vcpu); + void (*reset)(struct kvm_vcpu *vcpu); + void (*deliver_pmi)(struct kvm_vcpu *vcpu); + void (*cleanup)(struct kvm_vcpu *vcpu); + + const u64 EVENTSEL_EVENT; + const int MAX_NR_GP_COUNTERS; + const int MIN_NR_GP_COUNTERS; +}; + +void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops); + +static inline bool kvm_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu) +{ + /* + * Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is + * supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is + * greater than zero. However, KVM only exposes and emulates the MSR + * to/for the guest if the guest PMU supports at least "Architectural + * Performance Monitoring Version 2". + * + * AMD's version of PERF_GLOBAL_CTRL conveniently shows up with v2. + */ + return pmu->version > 1; +} + +static inline u64 pmc_bitmask(struct kvm_pmc *pmc) +{ + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + + return pmu->counter_bitmask[pmc->type]; +} + +static inline u64 pmc_read_counter(struct kvm_pmc *pmc) +{ + u64 counter, enabled, running; + + counter = pmc->counter; + if (pmc->perf_event && !pmc->is_paused) + counter += perf_event_read_value(pmc->perf_event, + &enabled, &running); + /* FIXME: Scaling needed? */ + return counter & pmc_bitmask(pmc); +} + +static inline void pmc_write_counter(struct kvm_pmc *pmc, u64 val) +{ + pmc->counter += val - pmc_read_counter(pmc); + pmc->counter &= pmc_bitmask(pmc); +} + +static inline bool pmc_is_gp(struct kvm_pmc *pmc) +{ + return pmc->type == KVM_PMC_GP; +} + +static inline bool pmc_is_fixed(struct kvm_pmc *pmc) +{ + return pmc->type == KVM_PMC_FIXED; +} + +static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu, + u64 data) +{ + return !(pmu->global_ctrl_mask & data); +} + +/* returns general purpose PMC with the specified MSR. Note that it can be + * used for both PERFCTRn and EVNTSELn; that is why it accepts base as a + * parameter to tell them apart. + */ +static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr, + u32 base) +{ + if (msr >= base && msr < base + pmu->nr_arch_gp_counters) { + u32 index = array_index_nospec(msr - base, + pmu->nr_arch_gp_counters); + + return &pmu->gp_counters[index]; + } + + return NULL; +} + +/* returns fixed PMC with the specified MSR */ +static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr) +{ + int base = MSR_CORE_PERF_FIXED_CTR0; + + if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) { + u32 index = array_index_nospec(msr - base, + pmu->nr_arch_fixed_counters); + + return &pmu->fixed_counters[index]; + } + + 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; +} + +static inline void pmc_update_sample_period(struct kvm_pmc *pmc) +{ + if (!pmc->perf_event || pmc->is_paused || + !is_sampling_event(pmc->perf_event)) + return; + + perf_event_period(pmc->perf_event, + get_sample_period(pmc, pmc->counter)); +} + +static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc) +{ + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + + if (pmc_is_fixed(pmc)) + return fixed_ctrl_field(pmu->fixed_ctr_ctrl, + pmc->idx - INTEL_PMC_IDX_FIXED) & 0x3; + + return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE; +} + +extern struct x86_pmu_capability kvm_pmu_cap; + +static inline 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; + + /* + * 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) { + perf_get_x86_pmu_capability(&kvm_pmu_cap); + + /* + * 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_pmu_cap.num_counters_gp || + WARN_ON_ONCE(kvm_pmu_cap.num_counters_gp < min_nr_gp_ctrs)) + enable_pmu = false; + else if (is_intel && !kvm_pmu_cap.version) + enable_pmu = false; + } + + if (!enable_pmu) { + memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap)); + return; + } + + 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_PMC_MAX_FIXED); +} + +static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc) +{ + set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi); + kvm_make_request(KVM_REQ_PMU, pmc->vcpu); +} + +static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff) +{ + int bit; + + if (!diff) + return; + + for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) + set_bit(bit, pmu->reprogram_pmi); + kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu)); +} + +/* + * Check if a PMC is enabled by comparing it against global_ctrl bits. + * + * If the vPMU doesn't have global_ctrl MSR, all vPMCs are enabled. + */ +static inline bool pmc_is_globally_enabled(struct kvm_pmc *pmc) +{ + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + + if (!kvm_pmu_has_perf_global_ctrl(pmu)) + return true; + + return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl); +} + +void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu); +void kvm_pmu_handle_event(struct kvm_vcpu *vcpu); +int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data); +bool kvm_pmu_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx); +bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr); +int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info); +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info); +void kvm_pmu_refresh(struct kvm_vcpu *vcpu); +void kvm_pmu_reset(struct kvm_vcpu *vcpu); +void kvm_pmu_init(struct kvm_vcpu *vcpu); +void kvm_pmu_cleanup(struct kvm_vcpu *vcpu); +void kvm_pmu_destroy(struct kvm_vcpu *vcpu); +int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp); +void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id); + +bool is_vmware_backdoor_pmc(u32 pmc_idx); + +extern struct kvm_pmu_ops intel_pmu_ops; +extern struct kvm_pmu_ops amd_pmu_ops; +#endif /* __KVM_X86_PMU_H */ |