arch/x86/kvm/pmu.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __KVM_X86_PMU_H
   3 #define __KVM_X86_PMU_H
   4
   5 #include <linux/nospec.h>
   6
   7 #define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
   8 #define pmu_to_vcpu(pmu)  (container_of((pmu), struct kvm_vcpu, arch.pmu))
   9 #define pmc_to_pmu(pmc)   (&(pmc)->vcpu->arch.pmu)
  10
  11 #define MSR_IA32_MISC_ENABLE_PMU_RO_MASK (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL |   \
  12                                           MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)
  13
  14 /* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
  15 #define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf)
  16
  17 #define VMWARE_BACKDOOR_PMC_HOST_TSC            0x10000
  18 #define VMWARE_BACKDOOR_PMC_REAL_TIME           0x10001
  19 #define VMWARE_BACKDOOR_PMC_APPARENT_TIME       0x10002
  20
  21 struct kvm_pmu_ops {
  22         bool (*hw_event_available)(struct kvm_pmc *pmc);
  23         struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);
  24         struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,
  25                 unsigned int idx, u64 *mask);
  26         struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, u32 msr);
  27         bool (*is_valid_rdpmc_ecx)(struct kvm_vcpu *vcpu, unsigned int idx);
  28         bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
  29         int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
  30         int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
  31         void (*refresh)(struct kvm_vcpu *vcpu);
  32         void (*init)(struct kvm_vcpu *vcpu);
  33         void (*reset)(struct kvm_vcpu *vcpu);
  34         void (*deliver_pmi)(struct kvm_vcpu *vcpu);
  35         void (*cleanup)(struct kvm_vcpu *vcpu);
  36
  37         const u64 EVENTSEL_EVENT;
  38         const int MAX_NR_GP_COUNTERS;
  39         const int MIN_NR_GP_COUNTERS;
  40 };
  41
  42 void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops);
  43
  44 static inline bool kvm_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu)
  45 {
  46         /*
  47          * Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is
  48          * supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is
  49          * greater than zero.  However, KVM only exposes and emulates the MSR
  50          * to/for the guest if the guest PMU supports at least "Architectural
  51          * Performance Monitoring Version 2".
  52          *
  53          * AMD's version of PERF_GLOBAL_CTRL conveniently shows up with v2.
  54          */
  55         return pmu->version > 1;
  56 }
  57
  58 static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
  59 {
  60         struct kvm_pmu *pmu = pmc_to_pmu(pmc);
  61
  62         return pmu->counter_bitmask[pmc->type];
  63 }
  64
  65 static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
  66 {
  67         u64 counter, enabled, running;
  68
  69         counter = pmc->counter;
  70         if (pmc->perf_event && !pmc->is_paused)
  71                 counter += perf_event_read_value(pmc->perf_event,
  72                                                  &enabled, &running);
  73         /* FIXME: Scaling needed? */
  74         return counter & pmc_bitmask(pmc);
  75 }
  76
  77 static inline void pmc_release_perf_event(struct kvm_pmc *pmc)
  78 {
  79         if (pmc->perf_event) {
  80                 perf_event_release_kernel(pmc->perf_event);
  81                 pmc->perf_event = NULL;
  82                 pmc->current_config = 0;
  83                 pmc_to_pmu(pmc)->event_count--;
  84         }
  85 }
  86
  87 static inline void pmc_stop_counter(struct kvm_pmc *pmc)
  88 {
  89         if (pmc->perf_event) {
  90                 pmc->counter = pmc_read_counter(pmc);
  91                 pmc_release_perf_event(pmc);
  92         }
  93 }
  94
  95 static inline bool pmc_is_gp(struct kvm_pmc *pmc)
  96 {
  97         return pmc->type == KVM_PMC_GP;
  98 }
  99
 100 static inline bool pmc_is_fixed(struct kvm_pmc *pmc)
 101 {
 102         return pmc->type == KVM_PMC_FIXED;
 103 }
 104
 105 static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu,
 106                                                  u64 data)
 107 {
 108         return !(pmu->global_ctrl_mask & data);
 109 }
 110
 111 /* returns general purpose PMC with the specified MSR. Note that it can be
 112  * used for both PERFCTRn and EVNTSELn; that is why it accepts base as a
 113  * parameter to tell them apart.
 114  */
 115 static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
 116                                          u32 base)
 117 {
 118         if (msr >= base && msr < base + pmu->nr_arch_gp_counters) {
 119                 u32 index = array_index_nospec(msr - base,
 120                                                pmu->nr_arch_gp_counters);
 121
 122                 return &pmu->gp_counters[index];
 123         }
 124
 125         return NULL;
 126 }
 127
 128 /* returns fixed PMC with the specified MSR */
 129 static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
 130 {
 131         int base = MSR_CORE_PERF_FIXED_CTR0;
 132
 133         if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) {
 134                 u32 index = array_index_nospec(msr - base,
 135                                                pmu->nr_arch_fixed_counters);
 136
 137                 return &pmu->fixed_counters[index];
 138         }
 139
 140         return NULL;
 141 }
 142
 143 static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value)
 144 {
 145         u64 sample_period = (-counter_value) & pmc_bitmask(pmc);
 146
 147         if (!sample_period)
 148                 sample_period = pmc_bitmask(pmc) + 1;
 149         return sample_period;
 150 }
 151
 152 static inline void pmc_update_sample_period(struct kvm_pmc *pmc)
 153 {
 154         if (!pmc->perf_event || pmc->is_paused ||
 155             !is_sampling_event(pmc->perf_event))
 156                 return;
 157
 158         perf_event_period(pmc->perf_event,
 159                           get_sample_period(pmc, pmc->counter));
 160 }
 161
 162 static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc)
 163 {
 164         struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 165
 166         if (pmc_is_fixed(pmc))
 167                 return fixed_ctrl_field(pmu->fixed_ctr_ctrl,
 168                                         pmc->idx - INTEL_PMC_IDX_FIXED) & 0x3;
 169
 170         return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
 171 }
 172
 173 extern struct x86_pmu_capability kvm_pmu_cap;
 174
 175 static inline void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops)
 176 {
 177         bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;
 178         int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS;
 179
 180         /*
 181          * Hybrid PMUs don't play nice with virtualization without careful
 182          * configuration by userspace, and KVM's APIs for reporting supported
 183          * vPMU features do not account for hybrid PMUs.  Disable vPMU support
 184          * for hybrid PMUs until KVM gains a way to let userspace opt-in.
 185          */
 186         if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
 187                 enable_pmu = false;
 188
 189         if (enable_pmu) {
 190                 perf_get_x86_pmu_capability(&kvm_pmu_cap);
 191
 192                 /*
 193                  * WARN if perf did NOT disable hardware PMU if the number of
 194                  * architecturally required GP counters aren't present, i.e. if
 195                  * there are a non-zero number of counters, but fewer than what
 196                  * is architecturally required.
 197                  */
 198                 if (!kvm_pmu_cap.num_counters_gp ||
 199                     WARN_ON_ONCE(kvm_pmu_cap.num_counters_gp < min_nr_gp_ctrs))
 200                         enable_pmu = false;
 201                 else if (is_intel && !kvm_pmu_cap.version)
 202                         enable_pmu = false;
 203         }
 204
 205         if (!enable_pmu) {
 206                 memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap));
 207                 return;
 208         }
 209
 210         kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2);
 211         kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp,
 212                                           pmu_ops->MAX_NR_GP_COUNTERS);
 213         kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed,
 214                                              KVM_PMC_MAX_FIXED);
 215 }
 216
 217 static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
 218 {
 219         set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
 220         kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
 221 }
 222
 223 static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
 224 {
 225         int bit;
 226
 227         if (!diff)
 228                 return;
 229
 230         for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
 231                 set_bit(bit, pmu->reprogram_pmi);
 232         kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu));
 233 }
 234
 235 /*
 236  * Check if a PMC is enabled by comparing it against global_ctrl bits.
 237  *
 238  * If the vPMU doesn't have global_ctrl MSR, all vPMCs are enabled.
 239  */
 240 static inline bool pmc_is_globally_enabled(struct kvm_pmc *pmc)
 241 {
 242         struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 243
 244         if (!kvm_pmu_has_perf_global_ctrl(pmu))
 245                 return true;
 246
 247         return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 248 }
 249
 250 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
 251 void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);
 252 int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
 253 bool kvm_pmu_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx);
 254 bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr);
 255 int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
 256 int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
 257 void kvm_pmu_refresh(struct kvm_vcpu *vcpu);
 258 void kvm_pmu_reset(struct kvm_vcpu *vcpu);
 259 void kvm_pmu_init(struct kvm_vcpu *vcpu);
 260 void kvm_pmu_cleanup(struct kvm_vcpu *vcpu);
 261 void kvm_pmu_destroy(struct kvm_vcpu *vcpu);
 262 int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp);
 263 void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id);
 264
 265 bool is_vmware_backdoor_pmc(u32 pmc_idx);
 266
 267 extern struct kvm_pmu_ops intel_pmu_ops;
 268 extern struct kvm_pmu_ops amd_pmu_ops;
 269 #endif /* __KVM_X86_PMU_H */