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