arch/x86/kvm/pmu_intel.c

   1 /*
   2  * KVM PMU support for Intel CPUs
   3  *
   4  * Copyright 2011 Red Hat, Inc. and/or its affiliates.
   5  *
   6  * Authors:
   7  *   Avi Kivity   <avi@redhat.com>
   8  *   Gleb Natapov <gleb@redhat.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  */
  14 #include <linux/types.h>
  15 #include <linux/kvm_host.h>
  16 #include <linux/perf_event.h>
  17 #include <asm/perf_event.h>
  18 #include "x86.h"
  19 #include "cpuid.h"
  20 #include "lapic.h"
  21 #include "pmu.h"
  22
  23 static struct kvm_event_hw_type_mapping intel_arch_events[] = {
  24         /* Index must match CPUID 0x0A.EBX bit vector */
  25         [0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
  26         [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
  27         [2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES  },
  28         [3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES },
  29         [4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES },
  30         [5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
  31         [6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
  32         [7] = { 0x00, 0x03, PERF_COUNT_HW_REF_CPU_CYCLES },
  33 };
  34
  35 /* mapping between fixed pmc index and intel_arch_events array */
  36 static int fixed_pmc_events[] = {1, 0, 7};
  37
  38 static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
  39 {
  40         int i;
  41
  42         for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
  43                 u8 new_ctrl = fixed_ctrl_field(data, i);
  44                 u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
  45                 struct kvm_pmc *pmc;
  46
  47                 pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
  48
  49                 if (old_ctrl == new_ctrl)
  50                         continue;
  51
  52                 reprogram_fixed_counter(pmc, new_ctrl, i);
  53         }
  54
  55         pmu->fixed_ctr_ctrl = data;
  56 }
  57
  58 /* function is called when global control register has been updated. */
  59 static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
  60 {
  61         int bit;
  62         u64 diff = pmu->global_ctrl ^ data;
  63
  64         pmu->global_ctrl = data;
  65
  66         for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
  67                 reprogram_counter(pmu, bit);
  68 }
  69
  70 static unsigned intel_find_arch_event(struct kvm_pmu *pmu,
  71                                       u8 event_select,
  72                                       u8 unit_mask)
  73 {
  74         int i;
  75
  76         for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++)
  77                 if (intel_arch_events[i].eventsel == event_select
  78                     && intel_arch_events[i].unit_mask == unit_mask
  79                     && (pmu->available_event_types & (1 << i)))
  80                         break;
  81
  82         if (i == ARRAY_SIZE(intel_arch_events))
  83                 return PERF_COUNT_HW_MAX;
  84
  85         return intel_arch_events[i].event_type;
  86 }
  87
  88 static unsigned intel_find_fixed_event(int idx)
  89 {
  90         u32 event;
  91         size_t size = ARRAY_SIZE(fixed_pmc_events);
  92
  93         if (idx >= size)
  94                 return PERF_COUNT_HW_MAX;
  95
  96         event = fixed_pmc_events[array_index_nospec(idx, size)];
  97         return intel_arch_events[event].event_type;
  98 }
  99
 100 /* check if a PMC is enabled by comparing it with globl_ctrl bits. */
 101 static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
 102 {
 103         struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 104
 105         return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 106 }
 107
 108 static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
 109 {
 110         if (pmc_idx < INTEL_PMC_IDX_FIXED)
 111                 return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
 112                                   MSR_P6_EVNTSEL0);
 113         else {
 114                 u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
 115
 116                 return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
 117         }
 118 }
 119
 120 /* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
 121 static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
 122 {
 123         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 124         bool fixed = idx & (1u << 30);
 125
 126         idx &= ~(3u << 30);
 127
 128         return (!fixed && idx >= pmu->nr_arch_gp_counters) ||
 129                 (fixed && idx >= pmu->nr_arch_fixed_counters);
 130 }
 131
 132 static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
 133                                             unsigned idx, u64 *mask)
 134 {
 135         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 136         bool fixed = idx & (1u << 30);
 137         struct kvm_pmc *counters;
 138         unsigned int num_counters;
 139
 140         idx &= ~(3u << 30);
 141         if (fixed) {
 142                 counters = pmu->fixed_counters;
 143                 num_counters = pmu->nr_arch_fixed_counters;
 144         } else {
 145                 counters = pmu->gp_counters;
 146                 num_counters = pmu->nr_arch_gp_counters;
 147         }
 148         if (idx >= num_counters)
 149                 return NULL;
 150         *mask &= pmu->counter_bitmask[fixed ? KVM_PMC_FIXED : KVM_PMC_GP];
 151         return &counters[array_index_nospec(idx, num_counters)];
 152 }
 153
 154 static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 155 {
 156         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 157         int ret;
 158
 159         switch (msr) {
 160         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 161         case MSR_CORE_PERF_GLOBAL_STATUS:
 162         case MSR_CORE_PERF_GLOBAL_CTRL:
 163         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 164                 ret = pmu->version > 1;
 165                 break;
 166         default:
 167                 ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
 168                         get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
 169                         get_fixed_pmc(pmu, msr);
 170                 break;
 171         }
 172
 173         return ret;
 174 }
 175
 176 static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
 177 {
 178         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 179         struct kvm_pmc *pmc;
 180
 181         switch (msr) {
 182         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 183                 *data = pmu->fixed_ctr_ctrl;
 184                 return 0;
 185         case MSR_CORE_PERF_GLOBAL_STATUS:
 186                 *data = pmu->global_status;
 187                 return 0;
 188         case MSR_CORE_PERF_GLOBAL_CTRL:
 189                 *data = pmu->global_ctrl;
 190                 return 0;
 191         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 192                 *data = pmu->global_ovf_ctrl;
 193                 return 0;
 194         default:
 195                 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
 196                         u64 val = pmc_read_counter(pmc);
 197                         *data = val & pmu->counter_bitmask[KVM_PMC_GP];
 198                         return 0;
 199                 } else if ((pmc = get_fixed_pmc(pmu, msr))) {
 200                         u64 val = pmc_read_counter(pmc);
 201                         *data = val & pmu->counter_bitmask[KVM_PMC_FIXED];
 202                         return 0;
 203                 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 204                         *data = pmc->eventsel;
 205                         return 0;
 206                 }
 207         }
 208
 209         return 1;
 210 }
 211
 212 static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 213 {
 214         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 215         struct kvm_pmc *pmc;
 216         u32 msr = msr_info->index;
 217         u64 data = msr_info->data;
 218
 219         switch (msr) {
 220         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 221                 if (pmu->fixed_ctr_ctrl == data)
 222                         return 0;
 223                 if (!(data & 0xfffffffffffff444ull)) {
 224                         reprogram_fixed_counters(pmu, data);
 225                         return 0;
 226                 }
 227                 break;
 228         case MSR_CORE_PERF_GLOBAL_STATUS:
 229                 if (msr_info->host_initiated) {
 230                         pmu->global_status = data;
 231                         return 0;
 232                 }
 233                 break; /* RO MSR */
 234         case MSR_CORE_PERF_GLOBAL_CTRL:
 235                 if (pmu->global_ctrl == data)
 236                         return 0;
 237                 if (!(data & pmu->global_ctrl_mask)) {
 238                         global_ctrl_changed(pmu, data);
 239                         return 0;
 240                 }
 241                 break;
 242         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 243                 if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) {
 244                         if (!msr_info->host_initiated)
 245                                 pmu->global_status &= ~data;
 246                         pmu->global_ovf_ctrl = data;
 247                         return 0;
 248                 }
 249                 break;
 250         default:
 251                 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
 252                         if (msr_info->host_initiated)
 253                                 pmc->counter = data;
 254                         else
 255                                 pmc->counter = (s32)data;
 256                         return 0;
 257                 } else if ((pmc = get_fixed_pmc(pmu, msr))) {
 258                         pmc->counter = data;
 259                         return 0;
 260                 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 261                         if (data == pmc->eventsel)
 262                                 return 0;
 263                         if (!(data & pmu->reserved_bits)) {
 264                                 reprogram_gp_counter(pmc, data);
 265                                 return 0;
 266                         }
 267                 }
 268         }
 269
 270         return 1;
 271 }
 272
 273 static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 274 {
 275         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 276         struct kvm_cpuid_entry2 *entry;
 277         union cpuid10_eax eax;
 278         union cpuid10_edx edx;
 279
 280         pmu->nr_arch_gp_counters = 0;
 281         pmu->nr_arch_fixed_counters = 0;
 282         pmu->counter_bitmask[KVM_PMC_GP] = 0;
 283         pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
 284         pmu->version = 0;
 285         pmu->reserved_bits = 0xffffffff00200000ull;
 286
 287         entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
 288         if (!entry)
 289                 return;
 290         eax.full = entry->eax;
 291         edx.full = entry->edx;
 292
 293         pmu->version = eax.split.version_id;
 294         if (!pmu->version)
 295                 return;
 296
 297         pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
 298                                         INTEL_PMC_MAX_GENERIC);
 299         pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1;
 300         pmu->available_event_types = ~entry->ebx &
 301                                         ((1ull << eax.split.mask_length) - 1);
 302
 303         if (pmu->version == 1) {
 304                 pmu->nr_arch_fixed_counters = 0;
 305         } else {
 306                 pmu->nr_arch_fixed_counters =
 307                         min_t(int, edx.split.num_counters_fixed,
 308                                 INTEL_PMC_MAX_FIXED);
 309                 pmu->counter_bitmask[KVM_PMC_FIXED] =
 310                         ((u64)1 << edx.split.bit_width_fixed) - 1;
 311         }
 312
 313         pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) |
 314                 (((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
 315         pmu->global_ctrl_mask = ~pmu->global_ctrl;
 316
 317         entry = kvm_find_cpuid_entry(vcpu, 7, 0);
 318         if (entry &&
 319             (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
 320             (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
 321                 pmu->reserved_bits ^= HSW_IN_TX|HSW_IN_TX_CHECKPOINTED;
 322 }
 323
 324 static void intel_pmu_init(struct kvm_vcpu *vcpu)
 325 {
 326         int i;
 327         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 328
 329         for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 330                 pmu->gp_counters[i].type = KVM_PMC_GP;
 331                 pmu->gp_counters[i].vcpu = vcpu;
 332                 pmu->gp_counters[i].idx = i;
 333         }
 334
 335         for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) {
 336                 pmu->fixed_counters[i].type = KVM_PMC_FIXED;
 337                 pmu->fixed_counters[i].vcpu = vcpu;
 338                 pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
 339         }
 340 }
 341
 342 static void intel_pmu_reset(struct kvm_vcpu *vcpu)
 343 {
 344         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 345         int i;
 346
 347         for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 348                 struct kvm_pmc *pmc = &pmu->gp_counters[i];
 349
 350                 pmc_stop_counter(pmc);
 351                 pmc->counter = pmc->eventsel = 0;
 352         }
 353
 354         for (i = 0; i < INTEL_PMC_MAX_FIXED; i++)
 355                 pmc_stop_counter(&pmu->fixed_counters[i]);
 356
 357         pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status =
 358                 pmu->global_ovf_ctrl = 0;
 359 }
 360
 361 struct kvm_pmu_ops intel_pmu_ops = {
 362         .find_arch_event = intel_find_arch_event,
 363         .find_fixed_event = intel_find_fixed_event,
 364         .pmc_is_enabled = intel_pmc_is_enabled,
 365         .pmc_idx_to_pmc = intel_pmc_idx_to_pmc,
 366         .msr_idx_to_pmc = intel_msr_idx_to_pmc,
 367         .is_valid_msr_idx = intel_is_valid_msr_idx,
 368         .is_valid_msr = intel_is_valid_msr,
 369         .get_msr = intel_pmu_get_msr,
 370         .set_msr = intel_pmu_set_msr,
 371         .refresh = intel_pmu_refresh,
 372         .init = intel_pmu_init,
 373         .reset = intel_pmu_reset,
 374 };