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