kernel/arch/x86/kvm/pmu.c

   1 /*
   2  * Kernel-based Virtual Machine -- Performance Monitoring Unit support
   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
  15 #include <linux/types.h>
  16 #include <linux/kvm_host.h>
  17 #include <linux/perf_event.h>
  18 #include <asm/perf_event.h>
  19 #include "x86.h"
  20 #include "cpuid.h"
  21 #include "lapic.h"
  22
  23 static struct kvm_arch_event_perf_mapping {
  24         u8 eventsel;
  25         u8 unit_mask;
  26         unsigned event_type;
  27         bool inexact;
  28 } arch_events[] = {
  29         /* Index must match CPUID 0x0A.EBX bit vector */
  30         [0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
  31         [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
  32         [2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES  },
  33         [3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES },
  34         [4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES },
  35         [5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
  36         [6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
  37         [7] = { 0x00, 0x30, PERF_COUNT_HW_REF_CPU_CYCLES },
  38 };
  39
  40 /* mapping between fixed pmc index and arch_events array */
  41 static int fixed_pmc_events[] = {1, 0, 7};
  42
  43 static bool pmc_is_gp(struct kvm_pmc *pmc)
  44 {
  45         return pmc->type == KVM_PMC_GP;
  46 }
  47
  48 static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
  49 {
  50         struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
  51
  52         return pmu->counter_bitmask[pmc->type];
  53 }
  54
  55 static inline bool pmc_enabled(struct kvm_pmc *pmc)
  56 {
  57         struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
  58         return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
  59 }
  60
  61 static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
  62                                          u32 base)
  63 {
  64         if (msr >= base && msr < base + pmu->nr_arch_gp_counters)
  65                 return &pmu->gp_counters[msr - base];
  66         return NULL;
  67 }
  68
  69 static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
  70 {
  71         int base = MSR_CORE_PERF_FIXED_CTR0;
  72         if (msr >= base && msr < base + pmu->nr_arch_fixed_counters)
  73                 return &pmu->fixed_counters[msr - base];
  74         return NULL;
  75 }
  76
  77 static inline struct kvm_pmc *get_fixed_pmc_idx(struct kvm_pmu *pmu, int idx)
  78 {
  79         return get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + idx);
  80 }
  81
  82 static struct kvm_pmc *global_idx_to_pmc(struct kvm_pmu *pmu, int idx)
  83 {
  84         if (idx < INTEL_PMC_IDX_FIXED)
  85                 return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + idx, MSR_P6_EVNTSEL0);
  86         else
  87                 return get_fixed_pmc_idx(pmu, idx - INTEL_PMC_IDX_FIXED);
  88 }
  89
  90 void kvm_deliver_pmi(struct kvm_vcpu *vcpu)
  91 {
  92         if (vcpu->arch.apic)
  93                 kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC);
  94 }
  95
  96 static void trigger_pmi(struct irq_work *irq_work)
  97 {
  98         struct kvm_pmu *pmu = container_of(irq_work, struct kvm_pmu,
  99                         irq_work);
 100         struct kvm_vcpu *vcpu = container_of(pmu, struct kvm_vcpu,
 101                         arch.pmu);
 102
 103         kvm_deliver_pmi(vcpu);
 104 }
 105
 106 static void kvm_perf_overflow(struct perf_event *perf_event,
 107                               struct perf_sample_data *data,
 108                               struct pt_regs *regs)
 109 {
 110         struct kvm_pmc *pmc = perf_event->overflow_handler_context;
 111         struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
 112         if (!test_and_set_bit(pmc->idx, (unsigned long *)&pmu->reprogram_pmi)) {
 113                 __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
 114                 kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
 115         }
 116 }
 117
 118 static void kvm_perf_overflow_intr(struct perf_event *perf_event,
 119                 struct perf_sample_data *data, struct pt_regs *regs)
 120 {
 121         struct kvm_pmc *pmc = perf_event->overflow_handler_context;
 122         struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
 123         if (!test_and_set_bit(pmc->idx, (unsigned long *)&pmu->reprogram_pmi)) {
 124                 __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
 125                 kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
 126                 /*
 127                  * Inject PMI. If vcpu was in a guest mode during NMI PMI
 128                  * can be ejected on a guest mode re-entry. Otherwise we can't
 129                  * be sure that vcpu wasn't executing hlt instruction at the
 130                  * time of vmexit and is not going to re-enter guest mode until,
 131                  * woken up. So we should wake it, but this is impossible from
 132                  * NMI context. Do it from irq work instead.
 133                  */
 134                 if (!kvm_is_in_guest())
 135                         irq_work_queue(&pmc->vcpu->arch.pmu.irq_work);
 136                 else
 137                         kvm_make_request(KVM_REQ_PMI, pmc->vcpu);
 138         }
 139 }
 140
 141 static u64 read_pmc(struct kvm_pmc *pmc)
 142 {
 143         u64 counter, enabled, running;
 144
 145         counter = pmc->counter;
 146
 147         if (pmc->perf_event)
 148                 counter += perf_event_read_value(pmc->perf_event,
 149                                                  &enabled, &running);
 150
 151         /* FIXME: Scaling needed? */
 152
 153         return counter & pmc_bitmask(pmc);
 154 }
 155
 156 static void stop_counter(struct kvm_pmc *pmc)
 157 {
 158         if (pmc->perf_event) {
 159                 pmc->counter = read_pmc(pmc);
 160                 perf_event_release_kernel(pmc->perf_event);
 161                 pmc->perf_event = NULL;
 162         }
 163 }
 164
 165 static void reprogram_counter(struct kvm_pmc *pmc, u32 type,
 166                 unsigned config, bool exclude_user, bool exclude_kernel,
 167                 bool intr, bool in_tx, bool in_tx_cp)
 168 {
 169         struct perf_event *event;
 170         struct perf_event_attr attr = {
 171                 .type = type,
 172                 .size = sizeof(attr),
 173                 .pinned = true,
 174                 .exclude_idle = true,
 175                 .exclude_host = 1,
 176                 .exclude_user = exclude_user,
 177                 .exclude_kernel = exclude_kernel,
 178                 .config = config,
 179         };
 180         if (in_tx)
 181                 attr.config |= HSW_IN_TX;
 182         if (in_tx_cp)
 183                 attr.config |= HSW_IN_TX_CHECKPOINTED;
 184
 185         attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc);
 186
 187         event = perf_event_create_kernel_counter(&attr, -1, current,
 188                                                  intr ? kvm_perf_overflow_intr :
 189                                                  kvm_perf_overflow, pmc);
 190         if (IS_ERR(event)) {
 191                 printk_once("kvm: pmu event creation failed %ld\n",
 192                                 PTR_ERR(event));
 193                 return;
 194         }
 195
 196         pmc->perf_event = event;
 197         clear_bit(pmc->idx, (unsigned long*)&pmc->vcpu->arch.pmu.reprogram_pmi);
 198 }
 199
 200 static unsigned find_arch_event(struct kvm_pmu *pmu, u8 event_select,
 201                 u8 unit_mask)
 202 {
 203         int i;
 204
 205         for (i = 0; i < ARRAY_SIZE(arch_events); i++)
 206                 if (arch_events[i].eventsel == event_select
 207                                 && arch_events[i].unit_mask == unit_mask
 208                                 && (pmu->available_event_types & (1 << i)))
 209                         break;
 210
 211         if (i == ARRAY_SIZE(arch_events))
 212                 return PERF_COUNT_HW_MAX;
 213
 214         return arch_events[i].event_type;
 215 }
 216
 217 static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
 218 {
 219         unsigned config, type = PERF_TYPE_RAW;
 220         u8 event_select, unit_mask;
 221
 222         if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
 223                 printk_once("kvm pmu: pin control bit is ignored\n");
 224
 225         pmc->eventsel = eventsel;
 226
 227         stop_counter(pmc);
 228
 229         if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_enabled(pmc))
 230                 return;
 231
 232         event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
 233         unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
 234
 235         if (!(eventsel & (ARCH_PERFMON_EVENTSEL_EDGE |
 236                                 ARCH_PERFMON_EVENTSEL_INV |
 237                                 ARCH_PERFMON_EVENTSEL_CMASK |
 238                                 HSW_IN_TX |
 239                                 HSW_IN_TX_CHECKPOINTED))) {
 240                 config = find_arch_event(&pmc->vcpu->arch.pmu, event_select,
 241                                 unit_mask);
 242                 if (config != PERF_COUNT_HW_MAX)
 243                         type = PERF_TYPE_HARDWARE;
 244         }
 245
 246         if (type == PERF_TYPE_RAW)
 247                 config = eventsel & X86_RAW_EVENT_MASK;
 248
 249         reprogram_counter(pmc, type, config,
 250                         !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
 251                         !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
 252                         eventsel & ARCH_PERFMON_EVENTSEL_INT,
 253                         (eventsel & HSW_IN_TX),
 254                         (eventsel & HSW_IN_TX_CHECKPOINTED));
 255 }
 256
 257 static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx)
 258 {
 259         unsigned en = en_pmi & 0x3;
 260         bool pmi = en_pmi & 0x8;
 261
 262         stop_counter(pmc);
 263
 264         if (!en || !pmc_enabled(pmc))
 265                 return;
 266
 267         reprogram_counter(pmc, PERF_TYPE_HARDWARE,
 268                         arch_events[fixed_pmc_events[idx]].event_type,
 269                         !(en & 0x2), /* exclude user */
 270                         !(en & 0x1), /* exclude kernel */
 271                         pmi, false, false);
 272 }
 273
 274 static inline u8 fixed_en_pmi(u64 ctrl, int idx)
 275 {
 276         return (ctrl >> (idx * 4)) & 0xf;
 277 }
 278
 279 static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 280 {
 281         int i;
 282
 283         for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
 284                 u8 en_pmi = fixed_en_pmi(data, i);
 285                 struct kvm_pmc *pmc = get_fixed_pmc_idx(pmu, i);
 286
 287                 if (fixed_en_pmi(pmu->fixed_ctr_ctrl, i) == en_pmi)
 288                         continue;
 289
 290                 reprogram_fixed_counter(pmc, en_pmi, i);
 291         }
 292
 293         pmu->fixed_ctr_ctrl = data;
 294 }
 295
 296 static void reprogram_idx(struct kvm_pmu *pmu, int idx)
 297 {
 298         struct kvm_pmc *pmc = global_idx_to_pmc(pmu, idx);
 299
 300         if (!pmc)
 301                 return;
 302
 303         if (pmc_is_gp(pmc))
 304                 reprogram_gp_counter(pmc, pmc->eventsel);
 305         else {
 306                 int fidx = idx - INTEL_PMC_IDX_FIXED;
 307                 reprogram_fixed_counter(pmc,
 308                                 fixed_en_pmi(pmu->fixed_ctr_ctrl, fidx), fidx);
 309         }
 310 }
 311
 312 static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
 313 {
 314         int bit;
 315         u64 diff = pmu->global_ctrl ^ data;
 316
 317         pmu->global_ctrl = data;
 318
 319         for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
 320                 reprogram_idx(pmu, bit);
 321 }
 322
 323 bool kvm_pmu_msr(struct kvm_vcpu *vcpu, u32 msr)
 324 {
 325         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 326         int ret;
 327
 328         switch (msr) {
 329         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 330         case MSR_CORE_PERF_GLOBAL_STATUS:
 331         case MSR_CORE_PERF_GLOBAL_CTRL:
 332         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 333                 ret = pmu->version > 1;
 334                 break;
 335         default:
 336                 ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)
 337                         || get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0)
 338                         || get_fixed_pmc(pmu, msr);
 339                 break;
 340         }
 341         return ret;
 342 }
 343
 344 int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data)
 345 {
 346         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 347         struct kvm_pmc *pmc;
 348
 349         switch (index) {
 350         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 351                 *data = pmu->fixed_ctr_ctrl;
 352                 return 0;
 353         case MSR_CORE_PERF_GLOBAL_STATUS:
 354                 *data = pmu->global_status;
 355                 return 0;
 356         case MSR_CORE_PERF_GLOBAL_CTRL:
 357                 *data = pmu->global_ctrl;
 358                 return 0;
 359         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 360                 *data = pmu->global_ovf_ctrl;
 361                 return 0;
 362         default:
 363                 if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) ||
 364                                 (pmc = get_fixed_pmc(pmu, index))) {
 365                         *data = read_pmc(pmc);
 366                         return 0;
 367                 } else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) {
 368                         *data = pmc->eventsel;
 369                         return 0;
 370                 }
 371         }
 372         return 1;
 373 }
 374
 375 int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 376 {
 377         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 378         struct kvm_pmc *pmc;
 379         u32 index = msr_info->index;
 380         u64 data = msr_info->data;
 381
 382         switch (index) {
 383         case MSR_CORE_PERF_FIXED_CTR_CTRL:
 384                 if (pmu->fixed_ctr_ctrl == data)
 385                         return 0;
 386                 if (!(data & 0xfffffffffffff444ull)) {
 387                         reprogram_fixed_counters(pmu, data);
 388                         return 0;
 389                 }
 390                 break;
 391         case MSR_CORE_PERF_GLOBAL_STATUS:
 392                 if (msr_info->host_initiated) {
 393                         pmu->global_status = data;
 394                         return 0;
 395                 }
 396                 break; /* RO MSR */
 397         case MSR_CORE_PERF_GLOBAL_CTRL:
 398                 if (pmu->global_ctrl == data)
 399                         return 0;
 400                 if (!(data & pmu->global_ctrl_mask)) {
 401                         global_ctrl_changed(pmu, data);
 402                         return 0;
 403                 }
 404                 break;
 405         case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 406                 if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) {
 407                         if (!msr_info->host_initiated)
 408                                 pmu->global_status &= ~data;
 409                         pmu->global_ovf_ctrl = data;
 410                         return 0;
 411                 }
 412                 break;
 413         default:
 414                 if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) ||
 415                                 (pmc = get_fixed_pmc(pmu, index))) {
 416                         if (!msr_info->host_initiated)
 417                                 data = (s64)(s32)data;
 418                         pmc->counter += data - read_pmc(pmc);
 419                         return 0;
 420                 } else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) {
 421                         if (data == pmc->eventsel)
 422                                 return 0;
 423                         if (!(data & pmu->reserved_bits)) {
 424                                 reprogram_gp_counter(pmc, data);
 425                                 return 0;
 426                         }
 427                 }
 428         }
 429         return 1;
 430 }
 431
 432 int kvm_pmu_check_pmc(struct kvm_vcpu *vcpu, unsigned pmc)
 433 {
 434         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 435         bool fixed = pmc & (1u << 30);
 436         pmc &= ~(3u << 30);
 437         return (!fixed && pmc >= pmu->nr_arch_gp_counters) ||
 438                 (fixed && pmc >= pmu->nr_arch_fixed_counters);
 439 }
 440
 441 int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data)
 442 {
 443         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 444         bool fast_mode = pmc & (1u << 31);
 445         bool fixed = pmc & (1u << 30);
 446         struct kvm_pmc *counters;
 447         u64 ctr;
 448
 449         pmc &= ~(3u << 30);
 450         if (!fixed && pmc >= pmu->nr_arch_gp_counters)
 451                 return 1;
 452         if (fixed && pmc >= pmu->nr_arch_fixed_counters)
 453                 return 1;
 454         counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
 455         ctr = read_pmc(&counters[pmc]);
 456         if (fast_mode)
 457                 ctr = (u32)ctr;
 458         *data = ctr;
 459
 460         return 0;
 461 }
 462
 463 void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu)
 464 {
 465         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 466         struct kvm_cpuid_entry2 *entry;
 467         union cpuid10_eax eax;
 468         union cpuid10_edx edx;
 469
 470         pmu->nr_arch_gp_counters = 0;
 471         pmu->nr_arch_fixed_counters = 0;
 472         pmu->counter_bitmask[KVM_PMC_GP] = 0;
 473         pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
 474         pmu->version = 0;
 475         pmu->reserved_bits = 0xffffffff00200000ull;
 476
 477         entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
 478         if (!entry)
 479                 return;
 480         eax.full = entry->eax;
 481         edx.full = entry->edx;
 482
 483         pmu->version = eax.split.version_id;
 484         if (!pmu->version)
 485                 return;
 486
 487         pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
 488                                         INTEL_PMC_MAX_GENERIC);
 489         pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1;
 490         pmu->available_event_types = ~entry->ebx &
 491                                         ((1ull << eax.split.mask_length) - 1);
 492
 493         if (pmu->version == 1) {
 494                 pmu->nr_arch_fixed_counters = 0;
 495         } else {
 496                 pmu->nr_arch_fixed_counters =
 497                         min_t(int, edx.split.num_counters_fixed,
 498                                 INTEL_PMC_MAX_FIXED);
 499                 pmu->counter_bitmask[KVM_PMC_FIXED] =
 500                         ((u64)1 << edx.split.bit_width_fixed) - 1;
 501         }
 502
 503         pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) |
 504                 (((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
 505         pmu->global_ctrl_mask = ~pmu->global_ctrl;
 506
 507         entry = kvm_find_cpuid_entry(vcpu, 7, 0);
 508         if (entry &&
 509             (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
 510             (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
 511                 pmu->reserved_bits ^= HSW_IN_TX|HSW_IN_TX_CHECKPOINTED;
 512 }
 513
 514 void kvm_pmu_init(struct kvm_vcpu *vcpu)
 515 {
 516         int i;
 517         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 518
 519         memset(pmu, 0, sizeof(*pmu));
 520         for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 521                 pmu->gp_counters[i].type = KVM_PMC_GP;
 522                 pmu->gp_counters[i].vcpu = vcpu;
 523                 pmu->gp_counters[i].idx = i;
 524         }
 525         for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) {
 526                 pmu->fixed_counters[i].type = KVM_PMC_FIXED;
 527                 pmu->fixed_counters[i].vcpu = vcpu;
 528                 pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
 529         }
 530         init_irq_work(&pmu->irq_work, trigger_pmi);
 531         kvm_pmu_cpuid_update(vcpu);
 532 }
 533
 534 void kvm_pmu_reset(struct kvm_vcpu *vcpu)
 535 {
 536         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 537         int i;
 538
 539         irq_work_sync(&pmu->irq_work);
 540         for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 541                 struct kvm_pmc *pmc = &pmu->gp_counters[i];
 542                 stop_counter(pmc);
 543                 pmc->counter = pmc->eventsel = 0;
 544         }
 545
 546         for (i = 0; i < INTEL_PMC_MAX_FIXED; i++)
 547                 stop_counter(&pmu->fixed_counters[i]);
 548
 549         pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status =
 550                 pmu->global_ovf_ctrl = 0;
 551 }
 552
 553 void kvm_pmu_destroy(struct kvm_vcpu *vcpu)
 554 {
 555         kvm_pmu_reset(vcpu);
 556 }
 557
 558 void kvm_handle_pmu_event(struct kvm_vcpu *vcpu)
 559 {
 560         struct kvm_pmu *pmu = &vcpu->arch.pmu;
 561         u64 bitmask;
 562         int bit;
 563
 564         bitmask = pmu->reprogram_pmi;
 565
 566         for_each_set_bit(bit, (unsigned long *)&bitmask, X86_PMC_IDX_MAX) {
 567                 struct kvm_pmc *pmc = global_idx_to_pmc(pmu, bit);
 568
 569                 if (unlikely(!pmc || !pmc->perf_event)) {
 570                         clear_bit(bit, (unsigned long *)&pmu->reprogram_pmi);
 571                         continue;
 572                 }
 573
 574                 reprogram_idx(pmu, bit);
 575         }
 576 }