1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * KVM PMU support for Intel CPUs 4 * 5 * Copyright 2011 Red Hat, Inc. and/or its affiliates. 6 * 7 * Authors: 8 * Avi Kivity <avi@redhat.com> 9 * Gleb Natapov <gleb@redhat.com> 10 */ 11 #include <linux/types.h> 12 #include <linux/kvm_host.h> 13 #include <linux/perf_event.h> 14 #include <asm/perf_event.h> 15 #include "x86.h" 16 #include "cpuid.h" 17 #include "lapic.h" 18 #include "nested.h" 19 #include "pmu.h" 20 21 #define MSR_PMC_FULL_WIDTH_BIT (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0) 22 23 static struct kvm_event_hw_type_mapping intel_arch_events[] = { 24 [0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES }, 25 [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS }, 26 [2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES }, 27 [3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES }, 28 [4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES }, 29 [5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS }, 30 [6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES }, 31 /* The above index must match CPUID 0x0A.EBX bit vector */ 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 __set_bit(INTEL_PMC_IDX_FIXED + i, pmu->pmc_in_use); 53 reprogram_fixed_counter(pmc, new_ctrl, i); 54 } 55 56 pmu->fixed_ctr_ctrl = data; 57 } 58 59 /* function is called when global control register has been updated. */ 60 static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data) 61 { 62 int bit; 63 u64 diff = pmu->global_ctrl ^ data; 64 65 pmu->global_ctrl = data; 66 67 for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) 68 reprogram_counter(pmu, bit); 69 } 70 71 static unsigned int intel_pmc_perf_hw_id(struct kvm_pmc *pmc) 72 { 73 struct kvm_pmu *pmu = pmc_to_pmu(pmc); 74 u8 event_select = pmc->eventsel & ARCH_PERFMON_EVENTSEL_EVENT; 75 u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; 76 int i; 77 78 for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++) { 79 if (intel_arch_events[i].eventsel != event_select || 80 intel_arch_events[i].unit_mask != unit_mask) 81 continue; 82 83 /* disable event that reported as not present by cpuid */ 84 if ((i < 7) && !(pmu->available_event_types & (1 << i))) 85 return PERF_COUNT_HW_MAX + 1; 86 87 break; 88 } 89 90 if (i == ARRAY_SIZE(intel_arch_events)) 91 return PERF_COUNT_HW_MAX; 92 93 return intel_arch_events[i].event_type; 94 } 95 96 /* check if a PMC is enabled by comparing it with globl_ctrl bits. */ 97 static bool intel_pmc_is_enabled(struct kvm_pmc *pmc) 98 { 99 struct kvm_pmu *pmu = pmc_to_pmu(pmc); 100 101 return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl); 102 } 103 104 static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx) 105 { 106 if (pmc_idx < INTEL_PMC_IDX_FIXED) 107 return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx, 108 MSR_P6_EVNTSEL0); 109 else { 110 u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED; 111 112 return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0); 113 } 114 } 115 116 static bool intel_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx) 117 { 118 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 119 bool fixed = idx & (1u << 30); 120 121 idx &= ~(3u << 30); 122 123 return fixed ? idx < pmu->nr_arch_fixed_counters 124 : idx < pmu->nr_arch_gp_counters; 125 } 126 127 static struct kvm_pmc *intel_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu, 128 unsigned int idx, u64 *mask) 129 { 130 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 131 bool fixed = idx & (1u << 30); 132 struct kvm_pmc *counters; 133 unsigned int num_counters; 134 135 idx &= ~(3u << 30); 136 if (fixed) { 137 counters = pmu->fixed_counters; 138 num_counters = pmu->nr_arch_fixed_counters; 139 } else { 140 counters = pmu->gp_counters; 141 num_counters = pmu->nr_arch_gp_counters; 142 } 143 if (idx >= num_counters) 144 return NULL; 145 *mask &= pmu->counter_bitmask[fixed ? KVM_PMC_FIXED : KVM_PMC_GP]; 146 return &counters[array_index_nospec(idx, num_counters)]; 147 } 148 149 static inline u64 vcpu_get_perf_capabilities(struct kvm_vcpu *vcpu) 150 { 151 if (!guest_cpuid_has(vcpu, X86_FEATURE_PDCM)) 152 return 0; 153 154 return vcpu->arch.perf_capabilities; 155 } 156 157 static inline bool fw_writes_is_enabled(struct kvm_vcpu *vcpu) 158 { 159 return (vcpu_get_perf_capabilities(vcpu) & PMU_CAP_FW_WRITES) != 0; 160 } 161 162 static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr) 163 { 164 if (!fw_writes_is_enabled(pmu_to_vcpu(pmu))) 165 return NULL; 166 167 return get_gp_pmc(pmu, msr, MSR_IA32_PMC0); 168 } 169 170 bool intel_pmu_lbr_is_compatible(struct kvm_vcpu *vcpu) 171 { 172 /* 173 * As a first step, a guest could only enable LBR feature if its 174 * cpu model is the same as the host because the LBR registers 175 * would be pass-through to the guest and they're model specific. 176 */ 177 return boot_cpu_data.x86_model == guest_cpuid_model(vcpu); 178 } 179 180 bool intel_pmu_lbr_is_enabled(struct kvm_vcpu *vcpu) 181 { 182 struct x86_pmu_lbr *lbr = vcpu_to_lbr_records(vcpu); 183 184 return lbr->nr && (vcpu_get_perf_capabilities(vcpu) & PMU_CAP_LBR_FMT); 185 } 186 187 static bool intel_pmu_is_valid_lbr_msr(struct kvm_vcpu *vcpu, u32 index) 188 { 189 struct x86_pmu_lbr *records = vcpu_to_lbr_records(vcpu); 190 bool ret = false; 191 192 if (!intel_pmu_lbr_is_enabled(vcpu)) 193 return ret; 194 195 ret = (index == MSR_LBR_SELECT) || (index == MSR_LBR_TOS) || 196 (index >= records->from && index < records->from + records->nr) || 197 (index >= records->to && index < records->to + records->nr); 198 199 if (!ret && records->info) 200 ret = (index >= records->info && index < records->info + records->nr); 201 202 return ret; 203 } 204 205 static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) 206 { 207 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 208 int ret; 209 210 switch (msr) { 211 case MSR_CORE_PERF_FIXED_CTR_CTRL: 212 case MSR_CORE_PERF_GLOBAL_STATUS: 213 case MSR_CORE_PERF_GLOBAL_CTRL: 214 case MSR_CORE_PERF_GLOBAL_OVF_CTRL: 215 ret = pmu->version > 1; 216 break; 217 default: 218 ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) || 219 get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) || 220 get_fixed_pmc(pmu, msr) || get_fw_gp_pmc(pmu, msr) || 221 intel_pmu_is_valid_lbr_msr(vcpu, msr); 222 break; 223 } 224 225 return ret; 226 } 227 228 static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr) 229 { 230 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 231 struct kvm_pmc *pmc; 232 233 pmc = get_fixed_pmc(pmu, msr); 234 pmc = pmc ? pmc : get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0); 235 pmc = pmc ? pmc : get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0); 236 237 return pmc; 238 } 239 240 static inline void intel_pmu_release_guest_lbr_event(struct kvm_vcpu *vcpu) 241 { 242 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 243 244 if (lbr_desc->event) { 245 perf_event_release_kernel(lbr_desc->event); 246 lbr_desc->event = NULL; 247 vcpu_to_pmu(vcpu)->event_count--; 248 } 249 } 250 251 int intel_pmu_create_guest_lbr_event(struct kvm_vcpu *vcpu) 252 { 253 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 254 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 255 struct perf_event *event; 256 257 /* 258 * The perf_event_attr is constructed in the minimum efficient way: 259 * - set 'pinned = true' to make it task pinned so that if another 260 * cpu pinned event reclaims LBR, the event->oncpu will be set to -1; 261 * - set '.exclude_host = true' to record guest branches behavior; 262 * 263 * - set '.config = INTEL_FIXED_VLBR_EVENT' to indicates host perf 264 * schedule the event without a real HW counter but a fake one; 265 * check is_guest_lbr_event() and __intel_get_event_constraints(); 266 * 267 * - set 'sample_type = PERF_SAMPLE_BRANCH_STACK' and 268 * 'branch_sample_type = PERF_SAMPLE_BRANCH_CALL_STACK | 269 * PERF_SAMPLE_BRANCH_USER' to configure it as a LBR callstack 270 * event, which helps KVM to save/restore guest LBR records 271 * during host context switches and reduces quite a lot overhead, 272 * check branch_user_callstack() and intel_pmu_lbr_sched_task(); 273 */ 274 struct perf_event_attr attr = { 275 .type = PERF_TYPE_RAW, 276 .size = sizeof(attr), 277 .config = INTEL_FIXED_VLBR_EVENT, 278 .sample_type = PERF_SAMPLE_BRANCH_STACK, 279 .pinned = true, 280 .exclude_host = true, 281 .branch_sample_type = PERF_SAMPLE_BRANCH_CALL_STACK | 282 PERF_SAMPLE_BRANCH_USER, 283 }; 284 285 if (unlikely(lbr_desc->event)) { 286 __set_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use); 287 return 0; 288 } 289 290 event = perf_event_create_kernel_counter(&attr, -1, 291 current, NULL, NULL); 292 if (IS_ERR(event)) { 293 pr_debug_ratelimited("%s: failed %ld\n", 294 __func__, PTR_ERR(event)); 295 return PTR_ERR(event); 296 } 297 lbr_desc->event = event; 298 pmu->event_count++; 299 __set_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use); 300 return 0; 301 } 302 303 /* 304 * It's safe to access LBR msrs from guest when they have not 305 * been passthrough since the host would help restore or reset 306 * the LBR msrs records when the guest LBR event is scheduled in. 307 */ 308 static bool intel_pmu_handle_lbr_msrs_access(struct kvm_vcpu *vcpu, 309 struct msr_data *msr_info, bool read) 310 { 311 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 312 u32 index = msr_info->index; 313 314 if (!intel_pmu_is_valid_lbr_msr(vcpu, index)) 315 return false; 316 317 if (!lbr_desc->event && intel_pmu_create_guest_lbr_event(vcpu) < 0) 318 goto dummy; 319 320 /* 321 * Disable irq to ensure the LBR feature doesn't get reclaimed by the 322 * host at the time the value is read from the msr, and this avoids the 323 * host LBR value to be leaked to the guest. If LBR has been reclaimed, 324 * return 0 on guest reads. 325 */ 326 local_irq_disable(); 327 if (lbr_desc->event->state == PERF_EVENT_STATE_ACTIVE) { 328 if (read) 329 rdmsrl(index, msr_info->data); 330 else 331 wrmsrl(index, msr_info->data); 332 __set_bit(INTEL_PMC_IDX_FIXED_VLBR, vcpu_to_pmu(vcpu)->pmc_in_use); 333 local_irq_enable(); 334 return true; 335 } 336 clear_bit(INTEL_PMC_IDX_FIXED_VLBR, vcpu_to_pmu(vcpu)->pmc_in_use); 337 local_irq_enable(); 338 339 dummy: 340 if (read) 341 msr_info->data = 0; 342 return true; 343 } 344 345 static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 346 { 347 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 348 struct kvm_pmc *pmc; 349 u32 msr = msr_info->index; 350 351 switch (msr) { 352 case MSR_CORE_PERF_FIXED_CTR_CTRL: 353 msr_info->data = pmu->fixed_ctr_ctrl; 354 return 0; 355 case MSR_CORE_PERF_GLOBAL_STATUS: 356 msr_info->data = pmu->global_status; 357 return 0; 358 case MSR_CORE_PERF_GLOBAL_CTRL: 359 msr_info->data = pmu->global_ctrl; 360 return 0; 361 case MSR_CORE_PERF_GLOBAL_OVF_CTRL: 362 msr_info->data = 0; 363 return 0; 364 default: 365 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || 366 (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { 367 u64 val = pmc_read_counter(pmc); 368 msr_info->data = 369 val & pmu->counter_bitmask[KVM_PMC_GP]; 370 return 0; 371 } else if ((pmc = get_fixed_pmc(pmu, msr))) { 372 u64 val = pmc_read_counter(pmc); 373 msr_info->data = 374 val & pmu->counter_bitmask[KVM_PMC_FIXED]; 375 return 0; 376 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { 377 msr_info->data = pmc->eventsel; 378 return 0; 379 } else if (intel_pmu_handle_lbr_msrs_access(vcpu, msr_info, true)) 380 return 0; 381 } 382 383 return 1; 384 } 385 386 static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 387 { 388 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 389 struct kvm_pmc *pmc; 390 u32 msr = msr_info->index; 391 u64 data = msr_info->data; 392 u64 reserved_bits; 393 394 switch (msr) { 395 case MSR_CORE_PERF_FIXED_CTR_CTRL: 396 if (pmu->fixed_ctr_ctrl == data) 397 return 0; 398 if (!(data & 0xfffffffffffff444ull)) { 399 reprogram_fixed_counters(pmu, data); 400 return 0; 401 } 402 break; 403 case MSR_CORE_PERF_GLOBAL_STATUS: 404 if (msr_info->host_initiated) { 405 pmu->global_status = data; 406 return 0; 407 } 408 break; /* RO MSR */ 409 case MSR_CORE_PERF_GLOBAL_CTRL: 410 if (pmu->global_ctrl == data) 411 return 0; 412 if (kvm_valid_perf_global_ctrl(pmu, data)) { 413 global_ctrl_changed(pmu, data); 414 return 0; 415 } 416 break; 417 case MSR_CORE_PERF_GLOBAL_OVF_CTRL: 418 if (!(data & pmu->global_ovf_ctrl_mask)) { 419 if (!msr_info->host_initiated) 420 pmu->global_status &= ~data; 421 return 0; 422 } 423 break; 424 default: 425 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || 426 (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { 427 if ((msr & MSR_PMC_FULL_WIDTH_BIT) && 428 (data & ~pmu->counter_bitmask[KVM_PMC_GP])) 429 return 1; 430 if (!msr_info->host_initiated && 431 !(msr & MSR_PMC_FULL_WIDTH_BIT)) 432 data = (s64)(s32)data; 433 pmc->counter += data - pmc_read_counter(pmc); 434 if (pmc->perf_event && !pmc->is_paused) 435 perf_event_period(pmc->perf_event, 436 get_sample_period(pmc, data)); 437 return 0; 438 } else if ((pmc = get_fixed_pmc(pmu, msr))) { 439 pmc->counter += data - pmc_read_counter(pmc); 440 if (pmc->perf_event && !pmc->is_paused) 441 perf_event_period(pmc->perf_event, 442 get_sample_period(pmc, data)); 443 return 0; 444 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { 445 if (data == pmc->eventsel) 446 return 0; 447 reserved_bits = pmu->reserved_bits; 448 if ((pmc->idx == 2) && 449 (pmu->raw_event_mask & HSW_IN_TX_CHECKPOINTED)) 450 reserved_bits ^= HSW_IN_TX_CHECKPOINTED; 451 if (!(data & reserved_bits)) { 452 reprogram_gp_counter(pmc, data); 453 return 0; 454 } 455 } else if (intel_pmu_handle_lbr_msrs_access(vcpu, msr_info, false)) 456 return 0; 457 } 458 459 return 1; 460 } 461 462 static void setup_fixed_pmc_eventsel(struct kvm_pmu *pmu) 463 { 464 size_t size = ARRAY_SIZE(fixed_pmc_events); 465 struct kvm_pmc *pmc; 466 u32 event; 467 int i; 468 469 for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { 470 pmc = &pmu->fixed_counters[i]; 471 event = fixed_pmc_events[array_index_nospec(i, size)]; 472 pmc->eventsel = (intel_arch_events[event].unit_mask << 8) | 473 intel_arch_events[event].eventsel; 474 } 475 } 476 477 static void intel_pmu_refresh(struct kvm_vcpu *vcpu) 478 { 479 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 480 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 481 482 struct x86_pmu_capability x86_pmu; 483 struct kvm_cpuid_entry2 *entry; 484 union cpuid10_eax eax; 485 union cpuid10_edx edx; 486 487 pmu->nr_arch_gp_counters = 0; 488 pmu->nr_arch_fixed_counters = 0; 489 pmu->counter_bitmask[KVM_PMC_GP] = 0; 490 pmu->counter_bitmask[KVM_PMC_FIXED] = 0; 491 pmu->version = 0; 492 pmu->reserved_bits = 0xffffffff00200000ull; 493 pmu->raw_event_mask = X86_RAW_EVENT_MASK; 494 495 entry = kvm_find_cpuid_entry(vcpu, 0xa, 0); 496 if (!entry || !vcpu->kvm->arch.enable_pmu) 497 return; 498 eax.full = entry->eax; 499 edx.full = entry->edx; 500 501 pmu->version = eax.split.version_id; 502 if (!pmu->version) 503 return; 504 505 perf_get_x86_pmu_capability(&x86_pmu); 506 507 pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters, 508 x86_pmu.num_counters_gp); 509 eax.split.bit_width = min_t(int, eax.split.bit_width, x86_pmu.bit_width_gp); 510 pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1; 511 eax.split.mask_length = min_t(int, eax.split.mask_length, x86_pmu.events_mask_len); 512 pmu->available_event_types = ~entry->ebx & 513 ((1ull << eax.split.mask_length) - 1); 514 515 if (pmu->version == 1) { 516 pmu->nr_arch_fixed_counters = 0; 517 } else { 518 pmu->nr_arch_fixed_counters = 519 min3(ARRAY_SIZE(fixed_pmc_events), 520 (size_t) edx.split.num_counters_fixed, 521 (size_t) x86_pmu.num_counters_fixed); 522 edx.split.bit_width_fixed = min_t(int, 523 edx.split.bit_width_fixed, x86_pmu.bit_width_fixed); 524 pmu->counter_bitmask[KVM_PMC_FIXED] = 525 ((u64)1 << edx.split.bit_width_fixed) - 1; 526 setup_fixed_pmc_eventsel(pmu); 527 } 528 529 pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) | 530 (((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED); 531 pmu->global_ctrl_mask = ~pmu->global_ctrl; 532 pmu->global_ovf_ctrl_mask = pmu->global_ctrl_mask 533 & ~(MSR_CORE_PERF_GLOBAL_OVF_CTRL_OVF_BUF | 534 MSR_CORE_PERF_GLOBAL_OVF_CTRL_COND_CHGD); 535 if (vmx_pt_mode_is_host_guest()) 536 pmu->global_ovf_ctrl_mask &= 537 ~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI; 538 539 entry = kvm_find_cpuid_entry(vcpu, 7, 0); 540 if (entry && 541 (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) && 542 (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM))) { 543 pmu->reserved_bits ^= HSW_IN_TX; 544 pmu->raw_event_mask |= (HSW_IN_TX|HSW_IN_TX_CHECKPOINTED); 545 } 546 547 bitmap_set(pmu->all_valid_pmc_idx, 548 0, pmu->nr_arch_gp_counters); 549 bitmap_set(pmu->all_valid_pmc_idx, 550 INTEL_PMC_MAX_GENERIC, pmu->nr_arch_fixed_counters); 551 552 nested_vmx_pmu_refresh(vcpu, 553 intel_is_valid_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL)); 554 555 if (intel_pmu_lbr_is_compatible(vcpu)) 556 x86_perf_get_lbr(&lbr_desc->records); 557 else 558 lbr_desc->records.nr = 0; 559 560 if (lbr_desc->records.nr) 561 bitmap_set(pmu->all_valid_pmc_idx, INTEL_PMC_IDX_FIXED_VLBR, 1); 562 } 563 564 static void intel_pmu_init(struct kvm_vcpu *vcpu) 565 { 566 int i; 567 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 568 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 569 570 for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) { 571 pmu->gp_counters[i].type = KVM_PMC_GP; 572 pmu->gp_counters[i].vcpu = vcpu; 573 pmu->gp_counters[i].idx = i; 574 pmu->gp_counters[i].current_config = 0; 575 } 576 577 for (i = 0; i < KVM_PMC_MAX_FIXED; i++) { 578 pmu->fixed_counters[i].type = KVM_PMC_FIXED; 579 pmu->fixed_counters[i].vcpu = vcpu; 580 pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED; 581 pmu->fixed_counters[i].current_config = 0; 582 } 583 584 vcpu->arch.perf_capabilities = vmx_get_perf_capabilities(); 585 lbr_desc->records.nr = 0; 586 lbr_desc->event = NULL; 587 lbr_desc->msr_passthrough = false; 588 } 589 590 static void intel_pmu_reset(struct kvm_vcpu *vcpu) 591 { 592 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 593 struct kvm_pmc *pmc = NULL; 594 int i; 595 596 for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) { 597 pmc = &pmu->gp_counters[i]; 598 599 pmc_stop_counter(pmc); 600 pmc->counter = pmc->eventsel = 0; 601 } 602 603 for (i = 0; i < KVM_PMC_MAX_FIXED; i++) { 604 pmc = &pmu->fixed_counters[i]; 605 606 pmc_stop_counter(pmc); 607 pmc->counter = 0; 608 } 609 610 pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = 0; 611 612 intel_pmu_release_guest_lbr_event(vcpu); 613 } 614 615 /* 616 * Emulate LBR_On_PMI behavior for 1 < pmu.version < 4. 617 * 618 * If Freeze_LBR_On_PMI = 1, the LBR is frozen on PMI and 619 * the KVM emulates to clear the LBR bit (bit 0) in IA32_DEBUGCTL. 620 * 621 * Guest needs to re-enable LBR to resume branches recording. 622 */ 623 static void intel_pmu_legacy_freezing_lbrs_on_pmi(struct kvm_vcpu *vcpu) 624 { 625 u64 data = vmcs_read64(GUEST_IA32_DEBUGCTL); 626 627 if (data & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI) { 628 data &= ~DEBUGCTLMSR_LBR; 629 vmcs_write64(GUEST_IA32_DEBUGCTL, data); 630 } 631 } 632 633 static void intel_pmu_deliver_pmi(struct kvm_vcpu *vcpu) 634 { 635 u8 version = vcpu_to_pmu(vcpu)->version; 636 637 if (!intel_pmu_lbr_is_enabled(vcpu)) 638 return; 639 640 if (version > 1 && version < 4) 641 intel_pmu_legacy_freezing_lbrs_on_pmi(vcpu); 642 } 643 644 static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set) 645 { 646 struct x86_pmu_lbr *lbr = vcpu_to_lbr_records(vcpu); 647 int i; 648 649 for (i = 0; i < lbr->nr; i++) { 650 vmx_set_intercept_for_msr(vcpu, lbr->from + i, MSR_TYPE_RW, set); 651 vmx_set_intercept_for_msr(vcpu, lbr->to + i, MSR_TYPE_RW, set); 652 if (lbr->info) 653 vmx_set_intercept_for_msr(vcpu, lbr->info + i, MSR_TYPE_RW, set); 654 } 655 656 vmx_set_intercept_for_msr(vcpu, MSR_LBR_SELECT, MSR_TYPE_RW, set); 657 vmx_set_intercept_for_msr(vcpu, MSR_LBR_TOS, MSR_TYPE_RW, set); 658 } 659 660 static inline void vmx_disable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) 661 { 662 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 663 664 if (!lbr_desc->msr_passthrough) 665 return; 666 667 vmx_update_intercept_for_lbr_msrs(vcpu, true); 668 lbr_desc->msr_passthrough = false; 669 } 670 671 static inline void vmx_enable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) 672 { 673 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 674 675 if (lbr_desc->msr_passthrough) 676 return; 677 678 vmx_update_intercept_for_lbr_msrs(vcpu, false); 679 lbr_desc->msr_passthrough = true; 680 } 681 682 /* 683 * Higher priority host perf events (e.g. cpu pinned) could reclaim the 684 * pmu resources (e.g. LBR) that were assigned to the guest. This is 685 * usually done via ipi calls (more details in perf_install_in_context). 686 * 687 * Before entering the non-root mode (with irq disabled here), double 688 * confirm that the pmu features enabled to the guest are not reclaimed 689 * by higher priority host events. Otherwise, disallow vcpu's access to 690 * the reclaimed features. 691 */ 692 void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu) 693 { 694 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 695 struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); 696 697 if (!lbr_desc->event) { 698 vmx_disable_lbr_msrs_passthrough(vcpu); 699 if (vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR) 700 goto warn; 701 if (test_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use)) 702 goto warn; 703 return; 704 } 705 706 if (lbr_desc->event->state < PERF_EVENT_STATE_ACTIVE) { 707 vmx_disable_lbr_msrs_passthrough(vcpu); 708 __clear_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use); 709 goto warn; 710 } else 711 vmx_enable_lbr_msrs_passthrough(vcpu); 712 713 return; 714 715 warn: 716 pr_warn_ratelimited("kvm: vcpu-%d: fail to passthrough LBR.\n", 717 vcpu->vcpu_id); 718 } 719 720 static void intel_pmu_cleanup(struct kvm_vcpu *vcpu) 721 { 722 if (!(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR)) 723 intel_pmu_release_guest_lbr_event(vcpu); 724 } 725 726 struct kvm_pmu_ops intel_pmu_ops = { 727 .pmc_perf_hw_id = intel_pmc_perf_hw_id, 728 .pmc_is_enabled = intel_pmc_is_enabled, 729 .pmc_idx_to_pmc = intel_pmc_idx_to_pmc, 730 .rdpmc_ecx_to_pmc = intel_rdpmc_ecx_to_pmc, 731 .msr_idx_to_pmc = intel_msr_idx_to_pmc, 732 .is_valid_rdpmc_ecx = intel_is_valid_rdpmc_ecx, 733 .is_valid_msr = intel_is_valid_msr, 734 .get_msr = intel_pmu_get_msr, 735 .set_msr = intel_pmu_set_msr, 736 .refresh = intel_pmu_refresh, 737 .init = intel_pmu_init, 738 .reset = intel_pmu_reset, 739 .deliver_pmi = intel_pmu_deliver_pmi, 740 .cleanup = intel_pmu_cleanup, 741 }; 742