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 } 577