pmu.h

Go to the documentation of this file.

/* 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 + pmc->emulated_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);
}
 
void pmc_write_counter(struct kvm_pmc *pmc, u64 val);
 
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 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_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 */