1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * intel_pt.c: Intel Processor Trace support 4 * Copyright (c) 2013-2015, Intel Corporation. 5 */ 6 7#include <errno.h> 8#include <stdbool.h> 9#include <linux/kernel.h> 10#include <linux/types.h> 11#include <linux/bitops.h> 12#include <linux/log2.h> 13#include <linux/zalloc.h> 14#include <cpuid.h> 15 16#include "../../../util/session.h" 17#include "../../../util/event.h" 18#include "../../../util/evlist.h" 19#include "../../../util/evsel.h" 20#include "../../../util/evsel_config.h" 21#include "../../../util/cpumap.h" 22#include "../../../util/mmap.h" 23#include <subcmd/parse-options.h> 24#include "../../../util/parse-events.h" 25#include "../../../util/pmu.h" 26#include "../../../util/debug.h" 27#include "../../../util/auxtrace.h" 28#include "../../../util/perf_api_probe.h" 29#include "../../../util/record.h" 30#include "../../../util/target.h" 31#include "../../../util/tsc.h" 32#include <internal/lib.h> // page_size 33#include "../../../util/intel-pt.h" 34 35#define KiB(x) ((x) * 1024) 36#define MiB(x) ((x) * 1024 * 1024) 37#define KiB_MASK(x) (KiB(x) - 1) 38#define MiB_MASK(x) (MiB(x) - 1) 39 40#define INTEL_PT_PSB_PERIOD_NEAR 256 41 42struct intel_pt_snapshot_ref { 43 void *ref_buf; 44 size_t ref_offset; 45 bool wrapped; 46}; 47 48struct intel_pt_recording { 49 struct auxtrace_record itr; 50 struct perf_pmu *intel_pt_pmu; 51 int have_sched_switch; 52 struct evlist *evlist; 53 bool snapshot_mode; 54 bool snapshot_init_done; 55 size_t snapshot_size; 56 size_t snapshot_ref_buf_size; 57 int snapshot_ref_cnt; 58 struct intel_pt_snapshot_ref *snapshot_refs; 59 size_t priv_size; 60}; 61 62static int intel_pt_parse_terms_with_default(const char *pmu_name, 63 struct list_head *formats, 64 const char *str, 65 u64 *config) 66{ 67 struct list_head *terms; 68 struct perf_event_attr attr = { .size = 0, }; 69 int err; 70 71 terms = malloc(sizeof(struct list_head)); 72 if (!terms) 73 return -ENOMEM; 74 75 INIT_LIST_HEAD(terms); 76 77 err = parse_events_terms(terms, str); 78 if (err) 79 goto out_free; 80 81 attr.config = *config; 82 err = perf_pmu__config_terms(pmu_name, formats, &attr, terms, true, 83 NULL); 84 if (err) 85 goto out_free; 86 87 *config = attr.config; 88out_free: 89 parse_events_terms__delete(terms); 90 return err; 91} 92 93static int intel_pt_parse_terms(const char *pmu_name, struct list_head *formats, 94 const char *str, u64 *config) 95{ 96 *config = 0; 97 return intel_pt_parse_terms_with_default(pmu_name, formats, str, 98 config); 99} 100 101static u64 intel_pt_masked_bits(u64 mask, u64 bits) 102{ 103 const u64 top_bit = 1ULL << 63; 104 u64 res = 0; 105 int i; 106 107 for (i = 0; i < 64; i++) { 108 if (mask & top_bit) { 109 res <<= 1; 110 if (bits & top_bit) 111 res |= 1; 112 } 113 mask <<= 1; 114 bits <<= 1; 115 } 116 117 return res; 118} 119 120static int intel_pt_read_config(struct perf_pmu *intel_pt_pmu, const char *str, 121 struct evlist *evlist, u64 *res) 122{ 123 struct evsel *evsel; 124 u64 mask; 125 126 *res = 0; 127 128 mask = perf_pmu__format_bits(&intel_pt_pmu->format, str); 129 if (!mask) 130 return -EINVAL; 131 132 evlist__for_each_entry(evlist, evsel) { 133 if (evsel->core.attr.type == intel_pt_pmu->type) { 134 *res = intel_pt_masked_bits(mask, evsel->core.attr.config); 135 return 0; 136 } 137 } 138 139 return -EINVAL; 140} 141 142static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu, 143 struct evlist *evlist) 144{ 145 u64 val; 146 int err, topa_multiple_entries; 147 size_t psb_period; 148 149 if (perf_pmu__scan_file(intel_pt_pmu, "caps/topa_multiple_entries", 150 "%d", &topa_multiple_entries) != 1) 151 topa_multiple_entries = 0; 152 153 /* 154 * Use caps/topa_multiple_entries to indicate early hardware that had 155 * extra frequent PSBs. 156 */ 157 if (!topa_multiple_entries) { 158 psb_period = 256; 159 goto out; 160 } 161 162 err = intel_pt_read_config(intel_pt_pmu, "psb_period", evlist, &val); 163 if (err) 164 val = 0; 165 166 psb_period = 1 << (val + 11); 167out: 168 pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period); 169 return psb_period; 170} 171 172static int intel_pt_pick_bit(int bits, int target) 173{ 174 int pos, pick = -1; 175 176 for (pos = 0; bits; bits >>= 1, pos++) { 177 if (bits & 1) { 178 if (pos <= target || pick < 0) 179 pick = pos; 180 if (pos >= target) 181 break; 182 } 183 } 184 185 return pick; 186} 187 188static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu) 189{ 190 char buf[256]; 191 int mtc, mtc_periods = 0, mtc_period; 192 int psb_cyc, psb_periods, psb_period; 193 int pos = 0; 194 u64 config; 195 char c; 196 197 pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc"); 198 199 if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc", "%d", 200 &mtc) != 1) 201 mtc = 1; 202 203 if (mtc) { 204 if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc_periods", "%x", 205 &mtc_periods) != 1) 206 mtc_periods = 0; 207 if (mtc_periods) { 208 mtc_period = intel_pt_pick_bit(mtc_periods, 3); 209 pos += scnprintf(buf + pos, sizeof(buf) - pos, 210 ",mtc,mtc_period=%d", mtc_period); 211 } 212 } 213 214 if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d", 215 &psb_cyc) != 1) 216 psb_cyc = 1; 217 218 if (psb_cyc && mtc_periods) { 219 if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x", 220 &psb_periods) != 1) 221 psb_periods = 0; 222 if (psb_periods) { 223 psb_period = intel_pt_pick_bit(psb_periods, 3); 224 pos += scnprintf(buf + pos, sizeof(buf) - pos, 225 ",psb_period=%d", psb_period); 226 } 227 } 228 229 if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 && 230 perf_pmu__scan_file(intel_pt_pmu, "format/branch", "%c", &c) == 1) 231 pos += scnprintf(buf + pos, sizeof(buf) - pos, ",pt,branch"); 232 233 pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf); 234 235 intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, buf, 236 &config); 237 238 return config; 239} 240 241static int intel_pt_parse_snapshot_options(struct auxtrace_record *itr, 242 struct record_opts *opts, 243 const char *str) 244{ 245 struct intel_pt_recording *ptr = 246 container_of(itr, struct intel_pt_recording, itr); 247 unsigned long long snapshot_size = 0; 248 char *endptr; 249 250 if (str) { 251 snapshot_size = strtoull(str, &endptr, 0); 252 if (*endptr || snapshot_size > SIZE_MAX) 253 return -1; 254 } 255 256 opts->auxtrace_snapshot_mode = true; 257 opts->auxtrace_snapshot_size = snapshot_size; 258 259 ptr->snapshot_size = snapshot_size; 260 261 return 0; 262} 263 264struct perf_event_attr * 265intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu) 266{ 267 struct perf_event_attr *attr; 268 269 attr = zalloc(sizeof(struct perf_event_attr)); 270 if (!attr) 271 return NULL; 272 273 attr->config = intel_pt_default_config(intel_pt_pmu); 274 275 intel_pt_pmu->selectable = true; 276 277 return attr; 278} 279 280static const char *intel_pt_find_filter(struct evlist *evlist, 281 struct perf_pmu *intel_pt_pmu) 282{ 283 struct evsel *evsel; 284 285 evlist__for_each_entry(evlist, evsel) { 286 if (evsel->core.attr.type == intel_pt_pmu->type) 287 return evsel->filter; 288 } 289 290 return NULL; 291} 292 293static size_t intel_pt_filter_bytes(const char *filter) 294{ 295 size_t len = filter ? strlen(filter) : 0; 296 297 return len ? roundup(len + 1, 8) : 0; 298} 299 300static size_t 301intel_pt_info_priv_size(struct auxtrace_record *itr, struct evlist *evlist) 302{ 303 struct intel_pt_recording *ptr = 304 container_of(itr, struct intel_pt_recording, itr); 305 const char *filter = intel_pt_find_filter(evlist, ptr->intel_pt_pmu); 306 307 ptr->priv_size = (INTEL_PT_AUXTRACE_PRIV_MAX * sizeof(u64)) + 308 intel_pt_filter_bytes(filter); 309 310 return ptr->priv_size; 311} 312 313static void intel_pt_tsc_ctc_ratio(u32 *n, u32 *d) 314{ 315 unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0; 316 317 __get_cpuid(0x15, &eax, &ebx, &ecx, &edx); 318 *n = ebx; 319 *d = eax; 320} 321 322static int intel_pt_info_fill(struct auxtrace_record *itr, 323 struct perf_session *session, 324 struct perf_record_auxtrace_info *auxtrace_info, 325 size_t priv_size) 326{ 327 struct intel_pt_recording *ptr = 328 container_of(itr, struct intel_pt_recording, itr); 329 struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu; 330 struct perf_event_mmap_page *pc; 331 struct perf_tsc_conversion tc = { .time_mult = 0, }; 332 bool cap_user_time_zero = false, per_cpu_mmaps; 333 u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit; 334 u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d; 335 unsigned long max_non_turbo_ratio; 336 size_t filter_str_len; 337 const char *filter; 338 __u64 *info; 339 int err; 340 341 if (priv_size != ptr->priv_size) 342 return -EINVAL; 343 344 intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, 345 "tsc", &tsc_bit); 346 intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, 347 "noretcomp", &noretcomp_bit); 348 intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, 349 "mtc", &mtc_bit); 350 mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format, 351 "mtc_period"); 352 intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, 353 "cyc", &cyc_bit); 354 355 intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d); 356 357 if (perf_pmu__scan_file(intel_pt_pmu, "max_nonturbo_ratio", 358 "%lu", &max_non_turbo_ratio) != 1) 359 max_non_turbo_ratio = 0; 360 361 filter = intel_pt_find_filter(session->evlist, ptr->intel_pt_pmu); 362 filter_str_len = filter ? strlen(filter) : 0; 363 364 if (!session->evlist->core.nr_mmaps) 365 return -EINVAL; 366 367 pc = session->evlist->mmap[0].core.base; 368 if (pc) { 369 err = perf_read_tsc_conversion(pc, &tc); 370 if (err) { 371 if (err != -EOPNOTSUPP) 372 return err; 373 } else { 374 cap_user_time_zero = tc.time_mult != 0; 375 } 376 if (!cap_user_time_zero) 377 ui__warning("Intel Processor Trace: TSC not available\n"); 378 } 379 380 per_cpu_mmaps = !perf_cpu_map__empty(session->evlist->core.cpus); 381 382 auxtrace_info->type = PERF_AUXTRACE_INTEL_PT; 383 auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type; 384 auxtrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift; 385 auxtrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult; 386 auxtrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero; 387 auxtrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero; 388 auxtrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit; 389 auxtrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit; 390 auxtrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch; 391 auxtrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode; 392 auxtrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps; 393 auxtrace_info->priv[INTEL_PT_MTC_BIT] = mtc_bit; 394 auxtrace_info->priv[INTEL_PT_MTC_FREQ_BITS] = mtc_freq_bits; 395 auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n; 396 auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d; 397 auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit; 398 auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO] = max_non_turbo_ratio; 399 auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] = filter_str_len; 400 401 info = &auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] + 1; 402 403 if (filter_str_len) { 404 size_t len = intel_pt_filter_bytes(filter); 405 406 strncpy((char *)info, filter, len); 407 info += len >> 3; 408 } 409 410 return 0; 411} 412 413static int intel_pt_track_switches(struct evlist *evlist) 414{ 415 const char *sched_switch = "sched:sched_switch"; 416 struct evsel *evsel; 417 int err; 418 419 if (!perf_evlist__can_select_event(evlist, sched_switch)) 420 return -EPERM; 421 422 err = parse_events(evlist, sched_switch, NULL); 423 if (err) { 424 pr_debug2("%s: failed to parse %s, error %d\n", 425 __func__, sched_switch, err); 426 return err; 427 } 428 429 evsel = evlist__last(evlist); 430 431 evsel__set_sample_bit(evsel, CPU); 432 evsel__set_sample_bit(evsel, TIME); 433 434 evsel->core.system_wide = true; 435 evsel->no_aux_samples = true; 436 evsel->immediate = true; 437 438 return 0; 439} 440 441static void intel_pt_valid_str(char *str, size_t len, u64 valid) 442{ 443 unsigned int val, last = 0, state = 1; 444 int p = 0; 445 446 str[0] = '\0'; 447 448 for (val = 0; val <= 64; val++, valid >>= 1) { 449 if (valid & 1) { 450 last = val; 451 switch (state) { 452 case 0: 453 p += scnprintf(str + p, len - p, ","); 454 /* Fall through */ 455 case 1: 456 p += scnprintf(str + p, len - p, "%u", val); 457 state = 2; 458 break; 459 case 2: 460 state = 3; 461 break; 462 case 3: 463 state = 4; 464 break; 465 default: 466 break; 467 } 468 } else { 469 switch (state) { 470 case 3: 471 p += scnprintf(str + p, len - p, ",%u", last); 472 state = 0; 473 break; 474 case 4: 475 p += scnprintf(str + p, len - p, "-%u", last); 476 state = 0; 477 break; 478 default: 479 break; 480 } 481 if (state != 1) 482 state = 0; 483 } 484 } 485} 486 487static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu, 488 const char *caps, const char *name, 489 const char *supported, u64 config) 490{ 491 char valid_str[256]; 492 unsigned int shift; 493 unsigned long long valid; 494 u64 bits; 495 int ok; 496 497 if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1) 498 valid = 0; 499 500 if (supported && 501 perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok) 502 valid = 0; 503 504 valid |= 1; 505 506 bits = perf_pmu__format_bits(&intel_pt_pmu->format, name); 507 508 config &= bits; 509 510 for (shift = 0; bits && !(bits & 1); shift++) 511 bits >>= 1; 512 513 config >>= shift; 514 515 if (config > 63) 516 goto out_err; 517 518 if (valid & (1 << config)) 519 return 0; 520out_err: 521 intel_pt_valid_str(valid_str, sizeof(valid_str), valid); 522 pr_err("Invalid %s for %s. Valid values are: %s\n", 523 name, INTEL_PT_PMU_NAME, valid_str); 524 return -EINVAL; 525} 526 527static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu, 528 struct evsel *evsel) 529{ 530 int err; 531 char c; 532 533 if (!evsel) 534 return 0; 535 536 /* 537 * If supported, force pass-through config term (pt=1) even if user 538 * sets pt=0, which avoids senseless kernel errors. 539 */ 540 if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 && 541 !(evsel->core.attr.config & 1)) { 542 pr_warning("pt=0 doesn't make sense, forcing pt=1\n"); 543 evsel->core.attr.config |= 1; 544 } 545 546 err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds", 547 "cyc_thresh", "caps/psb_cyc", 548 evsel->core.attr.config); 549 if (err) 550 return err; 551 552 err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods", 553 "mtc_period", "caps/mtc", 554 evsel->core.attr.config); 555 if (err) 556 return err; 557 558 return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods", 559 "psb_period", "caps/psb_cyc", 560 evsel->core.attr.config); 561} 562 563static void intel_pt_config_sample_mode(struct perf_pmu *intel_pt_pmu, 564 struct evsel *evsel) 565{ 566 u64 user_bits = 0, bits; 567 struct evsel_config_term *term = evsel__get_config_term(evsel, CFG_CHG); 568 569 if (term) 570 user_bits = term->val.cfg_chg; 571 572 bits = perf_pmu__format_bits(&intel_pt_pmu->format, "psb_period"); 573 574 /* Did user change psb_period */ 575 if (bits & user_bits) 576 return; 577 578 /* Set psb_period to 0 */ 579 evsel->core.attr.config &= ~bits; 580} 581 582static void intel_pt_min_max_sample_sz(struct evlist *evlist, 583 size_t *min_sz, size_t *max_sz) 584{ 585 struct evsel *evsel; 586 587 evlist__for_each_entry(evlist, evsel) { 588 size_t sz = evsel->core.attr.aux_sample_size; 589 590 if (!sz) 591 continue; 592 if (min_sz && (sz < *min_sz || !*min_sz)) 593 *min_sz = sz; 594 if (max_sz && sz > *max_sz) 595 *max_sz = sz; 596 } 597} 598 599/* 600 * Currently, there is not enough information to disambiguate different PEBS 601 * events, so only allow one. 602 */ 603static bool intel_pt_too_many_aux_output(struct evlist *evlist) 604{ 605 struct evsel *evsel; 606 int aux_output_cnt = 0; 607 608 evlist__for_each_entry(evlist, evsel) 609 aux_output_cnt += !!evsel->core.attr.aux_output; 610 611 if (aux_output_cnt > 1) { 612 pr_err(INTEL_PT_PMU_NAME " supports at most one event with aux-output\n"); 613 return true; 614 } 615 616 return false; 617} 618 619static int intel_pt_recording_options(struct auxtrace_record *itr, 620 struct evlist *evlist, 621 struct record_opts *opts) 622{ 623 struct intel_pt_recording *ptr = 624 container_of(itr, struct intel_pt_recording, itr); 625 struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu; 626 bool have_timing_info, need_immediate = false; 627 struct evsel *evsel, *intel_pt_evsel = NULL; 628 const struct perf_cpu_map *cpus = evlist->core.cpus; 629 bool privileged = perf_event_paranoid_check(-1); 630 u64 tsc_bit; 631 int err; 632 633 ptr->evlist = evlist; 634 ptr->snapshot_mode = opts->auxtrace_snapshot_mode; 635 636 evlist__for_each_entry(evlist, evsel) { 637 if (evsel->core.attr.type == intel_pt_pmu->type) { 638 if (intel_pt_evsel) { 639 pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n"); 640 return -EINVAL; 641 } 642 evsel->core.attr.freq = 0; 643 evsel->core.attr.sample_period = 1; 644 evsel->no_aux_samples = true; 645 intel_pt_evsel = evsel; 646 opts->full_auxtrace = true; 647 } 648 } 649 650 if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) { 651 pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n"); 652 return -EINVAL; 653 } 654 655 if (opts->auxtrace_snapshot_mode && opts->auxtrace_sample_mode) { 656 pr_err("Snapshot mode (" INTEL_PT_PMU_NAME " PMU) and sample trace cannot be used together\n"); 657 return -EINVAL; 658 } 659 660 if (opts->use_clockid) { 661 pr_err("Cannot use clockid (-k option) with " INTEL_PT_PMU_NAME "\n"); 662 return -EINVAL; 663 } 664 665 if (intel_pt_too_many_aux_output(evlist)) 666 return -EINVAL; 667 668 if (!opts->full_auxtrace) 669 return 0; 670 671 if (opts->auxtrace_sample_mode) 672 intel_pt_config_sample_mode(intel_pt_pmu, intel_pt_evsel); 673 674 err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel); 675 if (err) 676 return err; 677 678 /* Set default sizes for snapshot mode */ 679 if (opts->auxtrace_snapshot_mode) { 680 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist); 681 682 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) { 683 if (privileged) { 684 opts->auxtrace_mmap_pages = MiB(4) / page_size; 685 } else { 686 opts->auxtrace_mmap_pages = KiB(128) / page_size; 687 if (opts->mmap_pages == UINT_MAX) 688 opts->mmap_pages = KiB(256) / page_size; 689 } 690 } else if (!opts->auxtrace_mmap_pages && !privileged && 691 opts->mmap_pages == UINT_MAX) { 692 opts->mmap_pages = KiB(256) / page_size; 693 } 694 if (!opts->auxtrace_snapshot_size) 695 opts->auxtrace_snapshot_size = 696 opts->auxtrace_mmap_pages * (size_t)page_size; 697 if (!opts->auxtrace_mmap_pages) { 698 size_t sz = opts->auxtrace_snapshot_size; 699 700 sz = round_up(sz, page_size) / page_size; 701 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz); 702 } 703 if (opts->auxtrace_snapshot_size > 704 opts->auxtrace_mmap_pages * (size_t)page_size) { 705 pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n", 706 opts->auxtrace_snapshot_size, 707 opts->auxtrace_mmap_pages * (size_t)page_size); 708 return -EINVAL; 709 } 710 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) { 711 pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n"); 712 return -EINVAL; 713 } 714 pr_debug2("Intel PT snapshot size: %zu\n", 715 opts->auxtrace_snapshot_size); 716 if (psb_period && 717 opts->auxtrace_snapshot_size <= psb_period + 718 INTEL_PT_PSB_PERIOD_NEAR) 719 ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n", 720 opts->auxtrace_snapshot_size, psb_period); 721 } 722 723 /* Set default sizes for sample mode */ 724 if (opts->auxtrace_sample_mode) { 725 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist); 726 size_t min_sz = 0, max_sz = 0; 727 728 intel_pt_min_max_sample_sz(evlist, &min_sz, &max_sz); 729 if (!opts->auxtrace_mmap_pages && !privileged && 730 opts->mmap_pages == UINT_MAX) 731 opts->mmap_pages = KiB(256) / page_size; 732 if (!opts->auxtrace_mmap_pages) { 733 size_t sz = round_up(max_sz, page_size) / page_size; 734 735 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz); 736 } 737 if (max_sz > opts->auxtrace_mmap_pages * (size_t)page_size) { 738 pr_err("Sample size %zu must not be greater than AUX area tracing mmap size %zu\n", 739 max_sz, 740 opts->auxtrace_mmap_pages * (size_t)page_size); 741 return -EINVAL; 742 } 743 pr_debug2("Intel PT min. sample size: %zu max. sample size: %zu\n", 744 min_sz, max_sz); 745 if (psb_period && 746 min_sz <= psb_period + INTEL_PT_PSB_PERIOD_NEAR) 747 ui__warning("Intel PT sample size (%zu) may be too small for PSB period (%zu)\n", 748 min_sz, psb_period); 749 } 750 751 /* Set default sizes for full trace mode */ 752 if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) { 753 if (privileged) { 754 opts->auxtrace_mmap_pages = MiB(4) / page_size; 755 } else { 756 opts->auxtrace_mmap_pages = KiB(128) / page_size; 757 if (opts->mmap_pages == UINT_MAX) 758 opts->mmap_pages = KiB(256) / page_size; 759 } 760 } 761 762 /* Validate auxtrace_mmap_pages */ 763 if (opts->auxtrace_mmap_pages) { 764 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size; 765 size_t min_sz; 766 767 if (opts->auxtrace_snapshot_mode || opts->auxtrace_sample_mode) 768 min_sz = KiB(4); 769 else 770 min_sz = KiB(8); 771 772 if (sz < min_sz || !is_power_of_2(sz)) { 773 pr_err("Invalid mmap size for Intel Processor Trace: must be at least %zuKiB and a power of 2\n", 774 min_sz / 1024); 775 return -EINVAL; 776 } 777 } 778 779 intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, 780 "tsc", &tsc_bit); 781 782 if (opts->full_auxtrace && (intel_pt_evsel->core.attr.config & tsc_bit)) 783 have_timing_info = true; 784 else 785 have_timing_info = false; 786 787 /* 788 * Per-cpu recording needs sched_switch events to distinguish different 789 * threads. 790 */ 791 if (have_timing_info && !perf_cpu_map__empty(cpus) && 792 !record_opts__no_switch_events(opts)) { 793 if (perf_can_record_switch_events()) { 794 bool cpu_wide = !target__none(&opts->target) && 795 !target__has_task(&opts->target); 796 797 if (!cpu_wide && perf_can_record_cpu_wide()) { 798 struct evsel *switch_evsel; 799 800 err = parse_events(evlist, "dummy:u", NULL); 801 if (err) 802 return err; 803 804 switch_evsel = evlist__last(evlist); 805 806 switch_evsel->core.attr.freq = 0; 807 switch_evsel->core.attr.sample_period = 1; 808 switch_evsel->core.attr.context_switch = 1; 809 810 switch_evsel->core.system_wide = true; 811 switch_evsel->no_aux_samples = true; 812 switch_evsel->immediate = true; 813 814 evsel__set_sample_bit(switch_evsel, TID); 815 evsel__set_sample_bit(switch_evsel, TIME); 816 evsel__set_sample_bit(switch_evsel, CPU); 817 evsel__reset_sample_bit(switch_evsel, BRANCH_STACK); 818 819 opts->record_switch_events = false; 820 ptr->have_sched_switch = 3; 821 } else { 822 opts->record_switch_events = true; 823 need_immediate = true; 824 if (cpu_wide) 825 ptr->have_sched_switch = 3; 826 else 827 ptr->have_sched_switch = 2; 828 } 829 } else { 830 err = intel_pt_track_switches(evlist); 831 if (err == -EPERM) 832 pr_debug2("Unable to select sched:sched_switch\n"); 833 else if (err) 834 return err; 835 else 836 ptr->have_sched_switch = 1; 837 } 838 } 839 840 if (have_timing_info && !intel_pt_evsel->core.attr.exclude_kernel && 841 perf_can_record_text_poke_events() && perf_can_record_cpu_wide()) 842 opts->text_poke = true; 843 844 if (intel_pt_evsel) { 845 /* 846 * To obtain the auxtrace buffer file descriptor, the auxtrace 847 * event must come first. 848 */ 849 perf_evlist__to_front(evlist, intel_pt_evsel); 850 /* 851 * In the case of per-cpu mmaps, we need the CPU on the 852 * AUX event. 853 */ 854 if (!perf_cpu_map__empty(cpus)) 855 evsel__set_sample_bit(intel_pt_evsel, CPU); 856 } 857 858 /* Add dummy event to keep tracking */ 859 if (opts->full_auxtrace) { 860 struct evsel *tracking_evsel; 861 862 err = parse_events(evlist, "dummy:u", NULL); 863 if (err) 864 return err; 865 866 tracking_evsel = evlist__last(evlist); 867 868 perf_evlist__set_tracking_event(evlist, tracking_evsel); 869 870 tracking_evsel->core.attr.freq = 0; 871 tracking_evsel->core.attr.sample_period = 1; 872 873 tracking_evsel->no_aux_samples = true; 874 if (need_immediate) 875 tracking_evsel->immediate = true; 876 877 /* In per-cpu case, always need the time of mmap events etc */ 878 if (!perf_cpu_map__empty(cpus)) { 879 evsel__set_sample_bit(tracking_evsel, TIME); 880 /* And the CPU for switch events */ 881 evsel__set_sample_bit(tracking_evsel, CPU); 882 } 883 evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK); 884 } 885 886 /* 887 * Warn the user when we do not have enough information to decode i.e. 888 * per-cpu with no sched_switch (except workload-only). 889 */ 890 if (!ptr->have_sched_switch && !perf_cpu_map__empty(cpus) && 891 !target__none(&opts->target) && 892 !intel_pt_evsel->core.attr.exclude_user) 893 ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n"); 894 895 return 0; 896} 897 898static int intel_pt_snapshot_start(struct auxtrace_record *itr) 899{ 900 struct intel_pt_recording *ptr = 901 container_of(itr, struct intel_pt_recording, itr); 902 struct evsel *evsel; 903 904 evlist__for_each_entry(ptr->evlist, evsel) { 905 if (evsel->core.attr.type == ptr->intel_pt_pmu->type) 906 return evsel__disable(evsel); 907 } 908 return -EINVAL; 909} 910 911static int intel_pt_snapshot_finish(struct auxtrace_record *itr) 912{ 913 struct intel_pt_recording *ptr = 914 container_of(itr, struct intel_pt_recording, itr); 915 struct evsel *evsel; 916 917 evlist__for_each_entry(ptr->evlist, evsel) { 918 if (evsel->core.attr.type == ptr->intel_pt_pmu->type) 919 return evsel__enable(evsel); 920 } 921 return -EINVAL; 922} 923 924static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx) 925{ 926 const size_t sz = sizeof(struct intel_pt_snapshot_ref); 927 int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2; 928 struct intel_pt_snapshot_ref *refs; 929 930 if (!new_cnt) 931 new_cnt = 16; 932 933 while (new_cnt <= idx) 934 new_cnt *= 2; 935 936 refs = calloc(new_cnt, sz); 937 if (!refs) 938 return -ENOMEM; 939 940 memcpy(refs, ptr->snapshot_refs, cnt * sz); 941 942 ptr->snapshot_refs = refs; 943 ptr->snapshot_ref_cnt = new_cnt; 944 945 return 0; 946} 947 948static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr) 949{ 950 int i; 951 952 for (i = 0; i < ptr->snapshot_ref_cnt; i++) 953 zfree(&ptr->snapshot_refs[i].ref_buf); 954 zfree(&ptr->snapshot_refs); 955} 956 957static void intel_pt_recording_free(struct auxtrace_record *itr) 958{ 959 struct intel_pt_recording *ptr = 960 container_of(itr, struct intel_pt_recording, itr); 961 962 intel_pt_free_snapshot_refs(ptr); 963 free(ptr); 964} 965 966static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx, 967 size_t snapshot_buf_size) 968{ 969 size_t ref_buf_size = ptr->snapshot_ref_buf_size; 970 void *ref_buf; 971 972 ref_buf = zalloc(ref_buf_size); 973 if (!ref_buf) 974 return -ENOMEM; 975 976 ptr->snapshot_refs[idx].ref_buf = ref_buf; 977 ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size; 978 979 return 0; 980} 981 982static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr, 983 size_t snapshot_buf_size) 984{ 985 const size_t max_size = 256 * 1024; 986 size_t buf_size = 0, psb_period; 987 988 if (ptr->snapshot_size <= 64 * 1024) 989 return 0; 990 991 psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist); 992 if (psb_period) 993 buf_size = psb_period * 2; 994 995 if (!buf_size || buf_size > max_size) 996 buf_size = max_size; 997 998 if (buf_size >= snapshot_buf_size) 999 return 0; 1000 1001 if (buf_size >= ptr->snapshot_size / 2) 1002 return 0; 1003 1004 return buf_size; 1005} 1006 1007static int intel_pt_snapshot_init(struct intel_pt_recording *ptr, 1008 size_t snapshot_buf_size) 1009{ 1010 if (ptr->snapshot_init_done) 1011 return 0; 1012 1013 ptr->snapshot_init_done = true; 1014 1015 ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr, 1016 snapshot_buf_size); 1017 1018 return 0; 1019} 1020 1021/** 1022 * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer. 1023 * @buf1: first buffer 1024 * @compare_size: number of bytes to compare 1025 * @buf2: second buffer (a circular buffer) 1026 * @offs2: offset in second buffer 1027 * @buf2_size: size of second buffer 1028 * 1029 * The comparison allows for the possibility that the bytes to compare in the 1030 * circular buffer are not contiguous. It is assumed that @compare_size <= 1031 * @buf2_size. This function returns %false if the bytes are identical, %true 1032 * otherwise. 1033 */ 1034static bool intel_pt_compare_buffers(void *buf1, size_t compare_size, 1035 void *buf2, size_t offs2, size_t buf2_size) 1036{ 1037 size_t end2 = offs2 + compare_size, part_size; 1038 1039 if (end2 <= buf2_size) 1040 return memcmp(buf1, buf2 + offs2, compare_size); 1041 1042 part_size = end2 - buf2_size; 1043 if (memcmp(buf1, buf2 + offs2, part_size)) 1044 return true; 1045 1046 compare_size -= part_size; 1047 1048 return memcmp(buf1 + part_size, buf2, compare_size); 1049} 1050 1051static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset, 1052 size_t ref_size, size_t buf_size, 1053 void *data, size_t head) 1054{ 1055 size_t ref_end = ref_offset + ref_size; 1056 1057 if (ref_end > buf_size) { 1058 if (head > ref_offset || head < ref_end - buf_size) 1059 return true; 1060 } else if (head > ref_offset && head < ref_end) { 1061 return true; 1062 } 1063 1064 return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset, 1065 buf_size); 1066} 1067 1068static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size, 1069 void *data, size_t head) 1070{ 1071 if (head >= ref_size) { 1072 memcpy(ref_buf, data + head - ref_size, ref_size); 1073 } else { 1074 memcpy(ref_buf, data, head); 1075 ref_size -= head; 1076 memcpy(ref_buf + head, data + buf_size - ref_size, ref_size); 1077 } 1078} 1079 1080static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx, 1081 struct auxtrace_mmap *mm, unsigned char *data, 1082 u64 head) 1083{ 1084 struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx]; 1085 bool wrapped; 1086 1087 wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset, 1088 ptr->snapshot_ref_buf_size, mm->len, 1089 data, head); 1090 1091 intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len, 1092 data, head); 1093 1094 return wrapped; 1095} 1096 1097static bool intel_pt_first_wrap(u64 *data, size_t buf_size) 1098{ 1099 int i, a, b; 1100 1101 b = buf_size >> 3; 1102 a = b - 512; 1103 if (a < 0) 1104 a = 0; 1105 1106 for (i = a; i < b; i++) { 1107 if (data[i]) 1108 return true; 1109 } 1110 1111 return false; 1112} 1113 1114static int intel_pt_find_snapshot(struct auxtrace_record *itr, int idx, 1115 struct auxtrace_mmap *mm, unsigned char *data, 1116 u64 *head, u64 *old) 1117{ 1118 struct intel_pt_recording *ptr = 1119 container_of(itr, struct intel_pt_recording, itr); 1120 bool wrapped; 1121 int err; 1122 1123 pr_debug3("%s: mmap index %d old head %zu new head %zu\n", 1124 __func__, idx, (size_t)*old, (size_t)*head); 1125 1126 err = intel_pt_snapshot_init(ptr, mm->len); 1127 if (err) 1128 goto out_err; 1129 1130 if (idx >= ptr->snapshot_ref_cnt) { 1131 err = intel_pt_alloc_snapshot_refs(ptr, idx); 1132 if (err) 1133 goto out_err; 1134 } 1135 1136 if (ptr->snapshot_ref_buf_size) { 1137 if (!ptr->snapshot_refs[idx].ref_buf) { 1138 err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len); 1139 if (err) 1140 goto out_err; 1141 } 1142 wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head); 1143 } else { 1144 wrapped = ptr->snapshot_refs[idx].wrapped; 1145 if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) { 1146 ptr->snapshot_refs[idx].wrapped = true; 1147 wrapped = true; 1148 } 1149 } 1150 1151 /* 1152 * In full trace mode 'head' continually increases. However in snapshot 1153 * mode 'head' is an offset within the buffer. Here 'old' and 'head' 1154 * are adjusted to match the full trace case which expects that 'old' is 1155 * always less than 'head'. 1156 */ 1157 if (wrapped) { 1158 *old = *head; 1159 *head += mm->len; 1160 } else { 1161 if (mm->mask) 1162 *old &= mm->mask; 1163 else 1164 *old %= mm->len; 1165 if (*old > *head) 1166 *head += mm->len; 1167 } 1168 1169 pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n", 1170 __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head); 1171 1172 return 0; 1173 1174out_err: 1175 pr_err("%s: failed, error %d\n", __func__, err); 1176 return err; 1177} 1178 1179static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused) 1180{ 1181 return rdtsc(); 1182} 1183 1184struct auxtrace_record *intel_pt_recording_init(int *err) 1185{ 1186 struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME); 1187 struct intel_pt_recording *ptr; 1188 1189 if (!intel_pt_pmu) 1190 return NULL; 1191 1192 if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) { 1193 *err = -errno; 1194 return NULL; 1195 } 1196 1197 ptr = zalloc(sizeof(struct intel_pt_recording)); 1198 if (!ptr) { 1199 *err = -ENOMEM; 1200 return NULL; 1201 } 1202 1203 ptr->intel_pt_pmu = intel_pt_pmu; 1204 ptr->itr.pmu = intel_pt_pmu; 1205 ptr->itr.recording_options = intel_pt_recording_options; 1206 ptr->itr.info_priv_size = intel_pt_info_priv_size; 1207 ptr->itr.info_fill = intel_pt_info_fill; 1208 ptr->itr.free = intel_pt_recording_free; 1209 ptr->itr.snapshot_start = intel_pt_snapshot_start; 1210 ptr->itr.snapshot_finish = intel_pt_snapshot_finish; 1211 ptr->itr.find_snapshot = intel_pt_find_snapshot; 1212 ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options; 1213 ptr->itr.reference = intel_pt_reference; 1214 ptr->itr.read_finish = auxtrace_record__read_finish; 1215 /* 1216 * Decoding starts at a PSB packet. Minimum PSB period is 2K so 4K 1217 * should give at least 1 PSB per sample. 1218 */ 1219 ptr->itr.default_aux_sample_size = 4096; 1220 return &ptr->itr; 1221} 1222