migration/dirtyrate.c

   1 /*
   2  * Dirtyrate implement code
   3  *
   4  * Copyright (c) 2020 HUAWEI TECHNOLOGIES CO.,LTD.
   5  *
   6  * Authors:
   7  *  Chuan Zheng <zhengchuan@huawei.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qemu/osdep.h"
  14 #include "qemu/error-report.h"
  15 #include <zlib.h>
  16 #include "hw/core/cpu.h"
  17 #include "qapi/error.h"
  18 #include "exec/ramblock.h"
  19 #include "exec/target_page.h"
  20 #include "qemu/rcu_queue.h"
  21 #include "qemu/main-loop.h"
  22 #include "qapi/qapi-commands-migration.h"
  23 #include "ram.h"
  24 #include "trace.h"
  25 #include "dirtyrate.h"
  26 #include "monitor/hmp.h"
  27 #include "monitor/monitor.h"
  28 #include "qapi/qmp/qdict.h"
  29 #include "sysemu/kvm.h"
  30 #include "sysemu/runstate.h"
  31 #include "exec/memory.h"
  32 #include "qemu/xxhash.h"
  33
  34 /*
  35  * total_dirty_pages is procted by BQL and is used
  36  * to stat dirty pages during the period of two
  37  * memory_global_dirty_log_sync
  38  */
  39 uint64_t total_dirty_pages;
  40
  41 typedef struct DirtyPageRecord {
  42     uint64_t start_pages;
  43     uint64_t end_pages;
  44 } DirtyPageRecord;
  45
  46 static int CalculatingState = DIRTY_RATE_STATUS_UNSTARTED;
  47 static struct DirtyRateStat DirtyStat;
  48 static DirtyRateMeasureMode dirtyrate_mode =
  49                 DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING;
  50
  51 static int64_t dirty_stat_wait(int64_t msec, int64_t initial_time)
  52 {
  53     int64_t current_time;
  54
  55     current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
  56     if ((current_time - initial_time) >= msec) {
  57         msec = current_time - initial_time;
  58     } else {
  59         g_usleep((msec + initial_time - current_time) * 1000);
  60         /* g_usleep may overshoot */
  61         msec = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - initial_time;
  62     }
  63
  64     return msec;
  65 }
  66
  67 static inline void record_dirtypages(DirtyPageRecord *dirty_pages,
  68                                      CPUState *cpu, bool start)
  69 {
  70     if (start) {
  71         dirty_pages[cpu->cpu_index].start_pages = cpu->dirty_pages;
  72     } else {
  73         dirty_pages[cpu->cpu_index].end_pages = cpu->dirty_pages;
  74     }
  75 }
  76
  77 static int64_t do_calculate_dirtyrate(DirtyPageRecord dirty_pages,
  78                                       int64_t calc_time_ms)
  79 {
  80     uint64_t increased_dirty_pages =
  81         dirty_pages.end_pages - dirty_pages.start_pages;
  82
  83     /*
  84      * multiply by 1000ms/s _before_ converting down to megabytes
  85      * to avoid losing precision
  86      */
  87     return qemu_target_pages_to_MiB(increased_dirty_pages * 1000) /
  88         calc_time_ms;
  89 }
  90
  91 void global_dirty_log_change(unsigned int flag, bool start)
  92 {
  93     Error *local_err = NULL;
  94     bool ret;
  95
  96     bql_lock();
  97     if (start) {
  98         ret = memory_global_dirty_log_start(flag, &local_err);
  99         if (!ret) {
 100             error_report_err(local_err);
 101         }
 102     } else {
 103         memory_global_dirty_log_stop(flag);
 104     }
 105     bql_unlock();
 106 }
 107
 108 /*
 109  * global_dirty_log_sync
 110  * 1. sync dirty log from kvm
 111  * 2. stop dirty tracking if needed.
 112  */
 113 static void global_dirty_log_sync(unsigned int flag, bool one_shot)
 114 {
 115     bql_lock();
 116     memory_global_dirty_log_sync(false);
 117     if (one_shot) {
 118         memory_global_dirty_log_stop(flag);
 119     }
 120     bql_unlock();
 121 }
 122
 123 static DirtyPageRecord *vcpu_dirty_stat_alloc(VcpuStat *stat)
 124 {
 125     CPUState *cpu;
 126     int nvcpu = 0;
 127
 128     CPU_FOREACH(cpu) {
 129         nvcpu++;
 130     }
 131
 132     stat->nvcpu = nvcpu;
 133     stat->rates = g_new0(DirtyRateVcpu, nvcpu);
 134
 135     return g_new0(DirtyPageRecord, nvcpu);
 136 }
 137
 138 static void vcpu_dirty_stat_collect(DirtyPageRecord *records,
 139                                     bool start)
 140 {
 141     CPUState *cpu;
 142
 143     CPU_FOREACH(cpu) {
 144         record_dirtypages(records, cpu, start);
 145     }
 146 }
 147
 148 int64_t vcpu_calculate_dirtyrate(int64_t calc_time_ms,
 149                                  VcpuStat *stat,
 150                                  unsigned int flag,
 151                                  bool one_shot)
 152 {
 153     DirtyPageRecord *records;
 154     int64_t init_time_ms;
 155     int64_t duration;
 156     int64_t dirtyrate;
 157     int i = 0;
 158     unsigned int gen_id;
 159
 160 retry:
 161     init_time_ms = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 162
 163     WITH_QEMU_LOCK_GUARD(&qemu_cpu_list_lock) {
 164         gen_id = cpu_list_generation_id_get();
 165         records = vcpu_dirty_stat_alloc(stat);
 166         vcpu_dirty_stat_collect(records, true);
 167     }
 168
 169     duration = dirty_stat_wait(calc_time_ms, init_time_ms);
 170
 171     global_dirty_log_sync(flag, one_shot);
 172
 173     WITH_QEMU_LOCK_GUARD(&qemu_cpu_list_lock) {
 174         if (gen_id != cpu_list_generation_id_get()) {
 175             g_free(records);
 176             g_free(stat->rates);
 177             cpu_list_unlock();
 178             goto retry;
 179         }
 180         vcpu_dirty_stat_collect(records, false);
 181     }
 182
 183     for (i = 0; i < stat->nvcpu; i++) {
 184         dirtyrate = do_calculate_dirtyrate(records[i], duration);
 185
 186         stat->rates[i].id = i;
 187         stat->rates[i].dirty_rate = dirtyrate;
 188
 189         trace_dirtyrate_do_calculate_vcpu(i, dirtyrate);
 190     }
 191
 192     g_free(records);
 193
 194     return duration;
 195 }
 196
 197 static bool is_calc_time_valid(int64_t msec)
 198 {
 199     if ((msec < MIN_CALC_TIME_MS) || (msec > MAX_CALC_TIME_MS)) {
 200         return false;
 201     }
 202
 203     return true;
 204 }
 205
 206 static bool is_sample_pages_valid(int64_t pages)
 207 {
 208     return pages >= MIN_SAMPLE_PAGE_COUNT &&
 209            pages <= MAX_SAMPLE_PAGE_COUNT;
 210 }
 211
 212 static int dirtyrate_set_state(int *state, int old_state, int new_state)
 213 {
 214     assert(new_state < DIRTY_RATE_STATUS__MAX);
 215     trace_dirtyrate_set_state(DirtyRateStatus_str(new_state));
 216     if (qatomic_cmpxchg(state, old_state, new_state) == old_state) {
 217         return 0;
 218     } else {
 219         return -1;
 220     }
 221 }
 222
 223 /* Decimal power of given time unit relative to one second */
 224 static int time_unit_to_power(TimeUnit time_unit)
 225 {
 226     switch (time_unit) {
 227     case TIME_UNIT_SECOND:
 228         return 0;
 229     case TIME_UNIT_MILLISECOND:
 230         return -3;
 231     default:
 232         assert(false); /* unreachable */
 233         return 0;
 234     }
 235 }
 236
 237 static int64_t convert_time_unit(int64_t value, TimeUnit unit_from,
 238                                  TimeUnit unit_to)
 239 {
 240     int power = time_unit_to_power(unit_from) -
 241                 time_unit_to_power(unit_to);
 242     while (power < 0) {
 243         value /= 10;
 244         power += 1;
 245     }
 246     while (power > 0) {
 247         value *= 10;
 248         power -= 1;
 249     }
 250     return value;
 251 }
 252
 253
 254 static struct DirtyRateInfo *
 255 query_dirty_rate_info(TimeUnit calc_time_unit)
 256 {
 257     int i;
 258     int64_t dirty_rate = DirtyStat.dirty_rate;
 259     struct DirtyRateInfo *info = g_new0(DirtyRateInfo, 1);
 260     DirtyRateVcpuList *head = NULL, **tail = &head;
 261
 262     info->status = CalculatingState;
 263     info->start_time = DirtyStat.start_time;
 264     info->calc_time = convert_time_unit(DirtyStat.calc_time_ms,
 265                                         TIME_UNIT_MILLISECOND,
 266                                         calc_time_unit);
 267     info->calc_time_unit = calc_time_unit;
 268     info->sample_pages = DirtyStat.sample_pages;
 269     info->mode = dirtyrate_mode;
 270
 271     if (qatomic_read(&CalculatingState) == DIRTY_RATE_STATUS_MEASURED) {
 272         info->has_dirty_rate = true;
 273         info->dirty_rate = dirty_rate;
 274
 275         if (dirtyrate_mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 276             /*
 277              * set sample_pages with 0 to indicate page sampling
 278              * isn't enabled
 279              **/
 280             info->sample_pages = 0;
 281             info->has_vcpu_dirty_rate = true;
 282             for (i = 0; i < DirtyStat.dirty_ring.nvcpu; i++) {
 283                 DirtyRateVcpu *rate = g_new0(DirtyRateVcpu, 1);
 284                 rate->id = DirtyStat.dirty_ring.rates[i].id;
 285                 rate->dirty_rate = DirtyStat.dirty_ring.rates[i].dirty_rate;
 286                 QAPI_LIST_APPEND(tail, rate);
 287             }
 288             info->vcpu_dirty_rate = head;
 289         }
 290
 291         if (dirtyrate_mode == DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP) {
 292             info->sample_pages = 0;
 293         }
 294     }
 295
 296     trace_query_dirty_rate_info(DirtyRateStatus_str(CalculatingState));
 297
 298     return info;
 299 }
 300
 301 static void init_dirtyrate_stat(struct DirtyRateConfig config)
 302 {
 303     DirtyStat.dirty_rate = -1;
 304     DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
 305     DirtyStat.calc_time_ms = config.calc_time_ms;
 306     DirtyStat.sample_pages = config.sample_pages_per_gigabytes;
 307
 308     switch (config.mode) {
 309     case DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING:
 310         DirtyStat.page_sampling.total_dirty_samples = 0;
 311         DirtyStat.page_sampling.total_sample_count = 0;
 312         DirtyStat.page_sampling.total_block_mem_MB = 0;
 313         break;
 314     case DIRTY_RATE_MEASURE_MODE_DIRTY_RING:
 315         DirtyStat.dirty_ring.nvcpu = -1;
 316         DirtyStat.dirty_ring.rates = NULL;
 317         break;
 318     default:
 319         break;
 320     }
 321 }
 322
 323 static void cleanup_dirtyrate_stat(struct DirtyRateConfig config)
 324 {
 325     /* last calc-dirty-rate qmp use dirty ring mode */
 326     if (dirtyrate_mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 327         free(DirtyStat.dirty_ring.rates);
 328         DirtyStat.dirty_ring.rates = NULL;
 329     }
 330 }
 331
 332 static void update_dirtyrate_stat(struct RamblockDirtyInfo *info)
 333 {
 334     DirtyStat.page_sampling.total_dirty_samples += info->sample_dirty_count;
 335     DirtyStat.page_sampling.total_sample_count += info->sample_pages_count;
 336     /* size of total pages in MB */
 337     DirtyStat.page_sampling.total_block_mem_MB +=
 338         qemu_target_pages_to_MiB(info->ramblock_pages);
 339 }
 340
 341 static void update_dirtyrate(uint64_t msec)
 342 {
 343     uint64_t dirtyrate;
 344     uint64_t total_dirty_samples = DirtyStat.page_sampling.total_dirty_samples;
 345     uint64_t total_sample_count = DirtyStat.page_sampling.total_sample_count;
 346     uint64_t total_block_mem_MB = DirtyStat.page_sampling.total_block_mem_MB;
 347
 348     dirtyrate = total_dirty_samples * total_block_mem_MB *
 349                 1000 / (total_sample_count * msec);
 350
 351     DirtyStat.dirty_rate = dirtyrate;
 352 }
 353
 354 /*
 355  * Compute hash of a single page of size TARGET_PAGE_SIZE.
 356  */
 357 static uint32_t compute_page_hash(void *ptr)
 358 {
 359     size_t page_size = qemu_target_page_size();
 360     uint32_t i;
 361     uint64_t v1, v2, v3, v4;
 362     uint64_t res;
 363     const uint64_t *p = ptr;
 364
 365     v1 = QEMU_XXHASH_SEED + XXH_PRIME64_1 + XXH_PRIME64_2;
 366     v2 = QEMU_XXHASH_SEED + XXH_PRIME64_2;
 367     v3 = QEMU_XXHASH_SEED + 0;
 368     v4 = QEMU_XXHASH_SEED - XXH_PRIME64_1;
 369     for (i = 0; i < page_size / 8; i += 4) {
 370         v1 = XXH64_round(v1, p[i + 0]);
 371         v2 = XXH64_round(v2, p[i + 1]);
 372         v3 = XXH64_round(v3, p[i + 2]);
 373         v4 = XXH64_round(v4, p[i + 3]);
 374     }
 375     res = XXH64_mergerounds(v1, v2, v3, v4);
 376     res += page_size;
 377     res = XXH64_avalanche(res);
 378     return (uint32_t)(res & UINT32_MAX);
 379 }
 380
 381
 382 /*
 383  * get hash result for the sampled memory with length of TARGET_PAGE_SIZE
 384  * in ramblock, which starts from ramblock base address.
 385  */
 386 static uint32_t get_ramblock_vfn_hash(struct RamblockDirtyInfo *info,
 387                                       uint64_t vfn)
 388 {
 389     uint32_t hash;
 390
 391     hash = compute_page_hash(info->ramblock_addr +
 392                              vfn * qemu_target_page_size());
 393
 394     trace_get_ramblock_vfn_hash(info->idstr, vfn, hash);
 395     return hash;
 396 }
 397
 398 static bool save_ramblock_hash(struct RamblockDirtyInfo *info)
 399 {
 400     unsigned int sample_pages_count;
 401     int i;
 402     GRand *rand;
 403
 404     sample_pages_count = info->sample_pages_count;
 405
 406     /* ramblock size less than one page, return success to skip this ramblock */
 407     if (unlikely(info->ramblock_pages == 0 || sample_pages_count == 0)) {
 408         return true;
 409     }
 410
 411     info->hash_result = g_try_malloc0_n(sample_pages_count,
 412                                         sizeof(uint32_t));
 413     if (!info->hash_result) {
 414         return false;
 415     }
 416
 417     info->sample_page_vfn = g_try_malloc0_n(sample_pages_count,
 418                                             sizeof(uint64_t));
 419     if (!info->sample_page_vfn) {
 420         g_free(info->hash_result);
 421         return false;
 422     }
 423
 424     rand  = g_rand_new();
 425     for (i = 0; i < sample_pages_count; i++) {
 426         info->sample_page_vfn[i] = g_rand_int_range(rand, 0,
 427                                                     info->ramblock_pages - 1);
 428         info->hash_result[i] = get_ramblock_vfn_hash(info,
 429                                                      info->sample_page_vfn[i]);
 430     }
 431     g_rand_free(rand);
 432
 433     return true;
 434 }
 435
 436 static void get_ramblock_dirty_info(RAMBlock *block,
 437                                     struct RamblockDirtyInfo *info,
 438                                     struct DirtyRateConfig *config)
 439 {
 440     uint64_t sample_pages_per_gigabytes = config->sample_pages_per_gigabytes;
 441
 442     /* Right shift 30 bits to calc ramblock size in GB */
 443     info->sample_pages_count = (qemu_ram_get_used_length(block) *
 444                                 sample_pages_per_gigabytes) >> 30;
 445     /* Right shift TARGET_PAGE_BITS to calc page count */
 446     info->ramblock_pages = qemu_ram_get_used_length(block) >>
 447                            qemu_target_page_bits();
 448     info->ramblock_addr = qemu_ram_get_host_addr(block);
 449     strcpy(info->idstr, qemu_ram_get_idstr(block));
 450 }
 451
 452 static void free_ramblock_dirty_info(struct RamblockDirtyInfo *infos, int count)
 453 {
 454     int i;
 455
 456     if (!infos) {
 457         return;
 458     }
 459
 460     for (i = 0; i < count; i++) {
 461         g_free(infos[i].sample_page_vfn);
 462         g_free(infos[i].hash_result);
 463     }
 464     g_free(infos);
 465 }
 466
 467 static bool skip_sample_ramblock(RAMBlock *block)
 468 {
 469     /*
 470      * Sample only blocks larger than MIN_RAMBLOCK_SIZE.
 471      */
 472     if (qemu_ram_get_used_length(block) < (MIN_RAMBLOCK_SIZE << 10)) {
 473         trace_skip_sample_ramblock(block->idstr,
 474                                    qemu_ram_get_used_length(block));
 475         return true;
 476     }
 477
 478     return false;
 479 }
 480
 481 static bool record_ramblock_hash_info(struct RamblockDirtyInfo **block_dinfo,
 482                                       struct DirtyRateConfig config,
 483                                       int *block_count)
 484 {
 485     struct RamblockDirtyInfo *info = NULL;
 486     struct RamblockDirtyInfo *dinfo = NULL;
 487     RAMBlock *block = NULL;
 488     int total_count = 0;
 489     int index = 0;
 490     bool ret = false;
 491
 492     RAMBLOCK_FOREACH_MIGRATABLE(block) {
 493         if (skip_sample_ramblock(block)) {
 494             continue;
 495         }
 496         total_count++;
 497     }
 498
 499     dinfo = g_try_malloc0_n(total_count, sizeof(struct RamblockDirtyInfo));
 500     if (dinfo == NULL) {
 501         goto out;
 502     }
 503
 504     RAMBLOCK_FOREACH_MIGRATABLE(block) {
 505         if (skip_sample_ramblock(block)) {
 506             continue;
 507         }
 508         if (index >= total_count) {
 509             break;
 510         }
 511         info = &dinfo[index];
 512         get_ramblock_dirty_info(block, info, &config);
 513         if (!save_ramblock_hash(info)) {
 514             goto out;
 515         }
 516         index++;
 517     }
 518     ret = true;
 519
 520 out:
 521     *block_count = index;
 522     *block_dinfo = dinfo;
 523     return ret;
 524 }
 525
 526 static void calc_page_dirty_rate(struct RamblockDirtyInfo *info)
 527 {
 528     uint32_t hash;
 529     int i;
 530
 531     for (i = 0; i < info->sample_pages_count; i++) {
 532         hash = get_ramblock_vfn_hash(info, info->sample_page_vfn[i]);
 533         if (hash != info->hash_result[i]) {
 534             trace_calc_page_dirty_rate(info->idstr, hash, info->hash_result[i]);
 535             info->sample_dirty_count++;
 536         }
 537     }
 538 }
 539
 540 static struct RamblockDirtyInfo *
 541 find_block_matched(RAMBlock *block, int count,
 542                   struct RamblockDirtyInfo *infos)
 543 {
 544     int i;
 545
 546     for (i = 0; i < count; i++) {
 547         if (!strcmp(infos[i].idstr, qemu_ram_get_idstr(block))) {
 548             break;
 549         }
 550     }
 551
 552     if (i == count) {
 553         return NULL;
 554     }
 555
 556     if (infos[i].ramblock_addr != qemu_ram_get_host_addr(block) ||
 557         infos[i].ramblock_pages !=
 558             (qemu_ram_get_used_length(block) >> qemu_target_page_bits())) {
 559         trace_find_page_matched(block->idstr);
 560         return NULL;
 561     }
 562
 563     return &infos[i];
 564 }
 565
 566 static bool compare_page_hash_info(struct RamblockDirtyInfo *info,
 567                                   int block_count)
 568 {
 569     struct RamblockDirtyInfo *block_dinfo = NULL;
 570     RAMBlock *block = NULL;
 571
 572     RAMBLOCK_FOREACH_MIGRATABLE(block) {
 573         if (skip_sample_ramblock(block)) {
 574             continue;
 575         }
 576         block_dinfo = find_block_matched(block, block_count, info);
 577         if (block_dinfo == NULL) {
 578             continue;
 579         }
 580         calc_page_dirty_rate(block_dinfo);
 581         update_dirtyrate_stat(block_dinfo);
 582     }
 583
 584     if (DirtyStat.page_sampling.total_sample_count == 0) {
 585         return false;
 586     }
 587
 588     return true;
 589 }
 590
 591 static inline void record_dirtypages_bitmap(DirtyPageRecord *dirty_pages,
 592                                             bool start)
 593 {
 594     if (start) {
 595         dirty_pages->start_pages = total_dirty_pages;
 596     } else {
 597         dirty_pages->end_pages = total_dirty_pages;
 598     }
 599 }
 600
 601 static inline void dirtyrate_manual_reset_protect(void)
 602 {
 603     RAMBlock *block = NULL;
 604
 605     WITH_RCU_READ_LOCK_GUARD() {
 606         RAMBLOCK_FOREACH_MIGRATABLE(block) {
 607             memory_region_clear_dirty_bitmap(block->mr, 0,
 608                                              block->used_length);
 609         }
 610     }
 611 }
 612
 613 static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config)
 614 {
 615     int64_t start_time;
 616     DirtyPageRecord dirty_pages;
 617     Error *local_err = NULL;
 618
 619     bql_lock();
 620     if (!memory_global_dirty_log_start(GLOBAL_DIRTY_DIRTY_RATE, &local_err)) {
 621         error_report_err(local_err);
 622     }
 623
 624     /*
 625      * 1'round of log sync may return all 1 bits with
 626      * KVM_DIRTY_LOG_INITIALLY_SET enable
 627      * skip it unconditionally and start dirty tracking
 628      * from 2'round of log sync
 629      */
 630     memory_global_dirty_log_sync(false);
 631
 632     /*
 633      * reset page protect manually and unconditionally.
 634      * this make sure kvm dirty log be cleared if
 635      * KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE cap is enabled.
 636      */
 637     dirtyrate_manual_reset_protect();
 638     bql_unlock();
 639
 640     record_dirtypages_bitmap(&dirty_pages, true);
 641
 642     start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 643     DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
 644
 645     DirtyStat.calc_time_ms = dirty_stat_wait(config.calc_time_ms, start_time);
 646
 647     /*
 648      * do two things.
 649      * 1. fetch dirty bitmap from kvm
 650      * 2. stop dirty tracking
 651      */
 652     global_dirty_log_sync(GLOBAL_DIRTY_DIRTY_RATE, true);
 653
 654     record_dirtypages_bitmap(&dirty_pages, false);
 655
 656     DirtyStat.dirty_rate = do_calculate_dirtyrate(dirty_pages,
 657                                                   DirtyStat.calc_time_ms);
 658 }
 659
 660 static void calculate_dirtyrate_dirty_ring(struct DirtyRateConfig config)
 661 {
 662     uint64_t dirtyrate = 0;
 663     uint64_t dirtyrate_sum = 0;
 664     int i = 0;
 665
 666     /* start log sync */
 667     global_dirty_log_change(GLOBAL_DIRTY_DIRTY_RATE, true);
 668
 669     DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
 670
 671     /* calculate vcpu dirtyrate */
 672     DirtyStat.calc_time_ms = vcpu_calculate_dirtyrate(config.calc_time_ms,
 673                                                       &DirtyStat.dirty_ring,
 674                                                       GLOBAL_DIRTY_DIRTY_RATE,
 675                                                       true);
 676
 677     /* calculate vm dirtyrate */
 678     for (i = 0; i < DirtyStat.dirty_ring.nvcpu; i++) {
 679         dirtyrate = DirtyStat.dirty_ring.rates[i].dirty_rate;
 680         DirtyStat.dirty_ring.rates[i].dirty_rate = dirtyrate;
 681         dirtyrate_sum += dirtyrate;
 682     }
 683
 684     DirtyStat.dirty_rate = dirtyrate_sum;
 685 }
 686
 687 static void calculate_dirtyrate_sample_vm(struct DirtyRateConfig config)
 688 {
 689     struct RamblockDirtyInfo *block_dinfo = NULL;
 690     int block_count = 0;
 691     int64_t initial_time;
 692
 693     rcu_read_lock();
 694     initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 695     DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
 696     if (!record_ramblock_hash_info(&block_dinfo, config, &block_count)) {
 697         goto out;
 698     }
 699     rcu_read_unlock();
 700
 701     DirtyStat.calc_time_ms = dirty_stat_wait(config.calc_time_ms,
 702                                              initial_time);
 703
 704     rcu_read_lock();
 705     if (!compare_page_hash_info(block_dinfo, block_count)) {
 706         goto out;
 707     }
 708
 709     update_dirtyrate(DirtyStat.calc_time_ms);
 710
 711 out:
 712     rcu_read_unlock();
 713     free_ramblock_dirty_info(block_dinfo, block_count);
 714 }
 715
 716 static void calculate_dirtyrate(struct DirtyRateConfig config)
 717 {
 718     if (config.mode == DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP) {
 719         calculate_dirtyrate_dirty_bitmap(config);
 720     } else if (config.mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 721         calculate_dirtyrate_dirty_ring(config);
 722     } else {
 723         calculate_dirtyrate_sample_vm(config);
 724     }
 725
 726     trace_dirtyrate_calculate(DirtyStat.dirty_rate);
 727 }
 728
 729 void *get_dirtyrate_thread(void *arg)
 730 {
 731     struct DirtyRateConfig config = *(struct DirtyRateConfig *)arg;
 732     int ret;
 733     rcu_register_thread();
 734
 735     ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_UNSTARTED,
 736                               DIRTY_RATE_STATUS_MEASURING);
 737     if (ret == -1) {
 738         error_report("change dirtyrate state failed.");
 739         return NULL;
 740     }
 741
 742     calculate_dirtyrate(config);
 743
 744     ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_MEASURING,
 745                               DIRTY_RATE_STATUS_MEASURED);
 746     if (ret == -1) {
 747         error_report("change dirtyrate state failed.");
 748     }
 749
 750     rcu_unregister_thread();
 751     return NULL;
 752 }
 753
 754 void qmp_calc_dirty_rate(int64_t calc_time,
 755                          bool has_calc_time_unit,
 756                          TimeUnit calc_time_unit,
 757                          bool has_sample_pages,
 758                          int64_t sample_pages,
 759                          bool has_mode,
 760                          DirtyRateMeasureMode mode,
 761                          Error **errp)
 762 {
 763     static struct DirtyRateConfig config;
 764     QemuThread thread;
 765     int ret;
 766
 767     /*
 768      * If the dirty rate is already being measured, don't attempt to start.
 769      */
 770     if (qatomic_read(&CalculatingState) == DIRTY_RATE_STATUS_MEASURING) {
 771         error_setg(errp, "the dirty rate is already being measured.");
 772         return;
 773     }
 774
 775     int64_t calc_time_ms = convert_time_unit(
 776         calc_time,
 777         has_calc_time_unit ? calc_time_unit : TIME_UNIT_SECOND,
 778         TIME_UNIT_MILLISECOND
 779     );
 780
 781     if (!is_calc_time_valid(calc_time_ms)) {
 782         error_setg(errp, "Calculation time is out of range [%dms, %dms].",
 783                          MIN_CALC_TIME_MS, MAX_CALC_TIME_MS);
 784         return;
 785     }
 786
 787     if (!has_mode) {
 788         mode =  DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING;
 789     }
 790
 791     if (has_sample_pages && mode != DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING) {
 792         error_setg(errp, "sample-pages is used only in page-sampling mode");
 793         return;
 794     }
 795
 796     if (has_sample_pages) {
 797         if (!is_sample_pages_valid(sample_pages)) {
 798             error_setg(errp, "sample-pages is out of range[%d, %d].",
 799                             MIN_SAMPLE_PAGE_COUNT,
 800                             MAX_SAMPLE_PAGE_COUNT);
 801             return;
 802         }
 803     } else {
 804         sample_pages = DIRTYRATE_DEFAULT_SAMPLE_PAGES;
 805     }
 806
 807     /*
 808      * dirty ring mode only works when kvm dirty ring is enabled.
 809      * on the contrary, dirty bitmap mode is not.
 810      */
 811     if (((mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) &&
 812         !kvm_dirty_ring_enabled()) ||
 813         ((mode == DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP) &&
 814          kvm_dirty_ring_enabled())) {
 815         error_setg(errp, "mode %s is not enabled, use other method instead.",
 816                          DirtyRateMeasureMode_str(mode));
 817          return;
 818     }
 819
 820     /*
 821      * Init calculation state as unstarted.
 822      */
 823     ret = dirtyrate_set_state(&CalculatingState, CalculatingState,
 824                               DIRTY_RATE_STATUS_UNSTARTED);
 825     if (ret == -1) {
 826         error_setg(errp, "init dirty rate calculation state failed.");
 827         return;
 828     }
 829
 830     config.calc_time_ms = calc_time_ms;
 831     config.sample_pages_per_gigabytes = sample_pages;
 832     config.mode = mode;
 833
 834     cleanup_dirtyrate_stat(config);
 835
 836     /*
 837      * update dirty rate mode so that we can figure out what mode has
 838      * been used in last calculation
 839      **/
 840     dirtyrate_mode = mode;
 841
 842     init_dirtyrate_stat(config);
 843
 844     qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread,
 845                        (void *)&config, QEMU_THREAD_DETACHED);
 846 }
 847
 848
 849 struct DirtyRateInfo *qmp_query_dirty_rate(bool has_calc_time_unit,
 850                                            TimeUnit calc_time_unit,
 851                                            Error **errp)
 852 {
 853     return query_dirty_rate_info(
 854         has_calc_time_unit ? calc_time_unit : TIME_UNIT_SECOND);
 855 }
 856
 857 void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict)
 858 {
 859     DirtyRateInfo *info = query_dirty_rate_info(TIME_UNIT_SECOND);
 860
 861     monitor_printf(mon, "Status: %s\n",
 862                    DirtyRateStatus_str(info->status));
 863     monitor_printf(mon, "Start Time: %"PRIi64" (ms)\n",
 864                    info->start_time);
 865     if (info->mode == DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING) {
 866         monitor_printf(mon, "Sample Pages: %"PRIu64" (per GB)\n",
 867                        info->sample_pages);
 868     }
 869     monitor_printf(mon, "Period: %"PRIi64" (sec)\n",
 870                    info->calc_time);
 871     monitor_printf(mon, "Mode: %s\n",
 872                    DirtyRateMeasureMode_str(info->mode));
 873     monitor_printf(mon, "Dirty rate: ");
 874     if (info->has_dirty_rate) {
 875         monitor_printf(mon, "%"PRIi64" (MB/s)\n", info->dirty_rate);
 876         if (info->has_vcpu_dirty_rate) {
 877             DirtyRateVcpuList *rate, *head = info->vcpu_dirty_rate;
 878             for (rate = head; rate != NULL; rate = rate->next) {
 879                 monitor_printf(mon, "vcpu[%"PRIi64"], Dirty rate: %"PRIi64
 880                                " (MB/s)\n", rate->value->id,
 881                                rate->value->dirty_rate);
 882             }
 883         }
 884     } else {
 885         monitor_printf(mon, "(not ready)\n");
 886     }
 887
 888     qapi_free_DirtyRateVcpuList(info->vcpu_dirty_rate);
 889     g_free(info);
 890 }
 891
 892 void hmp_calc_dirty_rate(Monitor *mon, const QDict *qdict)
 893 {
 894     int64_t sec = qdict_get_try_int(qdict, "second", 0);
 895     int64_t sample_pages = qdict_get_try_int(qdict, "sample_pages_per_GB", -1);
 896     bool has_sample_pages = (sample_pages != -1);
 897     bool dirty_ring = qdict_get_try_bool(qdict, "dirty_ring", false);
 898     bool dirty_bitmap = qdict_get_try_bool(qdict, "dirty_bitmap", false);
 899     DirtyRateMeasureMode mode = DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING;
 900     Error *err = NULL;
 901
 902     if (!sec) {
 903         monitor_printf(mon, "Incorrect period length specified!\n");
 904         return;
 905     }
 906
 907     if (dirty_ring && dirty_bitmap) {
 908         monitor_printf(mon, "Either dirty ring or dirty bitmap "
 909                        "can be specified!\n");
 910         return;
 911     }
 912
 913     if (dirty_bitmap) {
 914         mode = DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP;
 915     } else if (dirty_ring) {
 916         mode = DIRTY_RATE_MEASURE_MODE_DIRTY_RING;
 917     }
 918
 919     qmp_calc_dirty_rate(sec, /* calc-time */
 920                         false, TIME_UNIT_SECOND, /* calc-time-unit */
 921                         has_sample_pages, sample_pages,
 922                         true, mode,
 923                         &err);
 924     if (err) {
 925         hmp_handle_error(mon, err);
 926         return;
 927     }
 928
 929     monitor_printf(mon, "Starting dirty rate measurement with period %"PRIi64
 930                    " seconds\n", sec);
 931     monitor_printf(mon, "[Please use 'info dirty_rate' to check results]\n");
 932 }