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