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 <zlib.h>
  15 #include "qapi/error.h"
  16 #include "cpu.h"
  17 #include "exec/ramblock.h"
  18 #include "exec/ram_addr.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
  32 /*
  33  * total_dirty_pages is procted by BQL and is used
  34  * to stat dirty pages during the period of two
  35  * memory_global_dirty_log_sync
  36  */
  37 uint64_t total_dirty_pages;
  38
  39 typedef struct DirtyPageRecord {
  40     uint64_t start_pages;
  41     uint64_t end_pages;
  42 } DirtyPageRecord;
  43
  44 static int CalculatingState = DIRTY_RATE_STATUS_UNSTARTED;
  45 static struct DirtyRateStat DirtyStat;
  46 static DirtyRateMeasureMode dirtyrate_mode =
  47                 DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING;
  48
  49 static int64_t dirty_stat_wait(int64_t msec, int64_t initial_time)
  50 {
  51     int64_t current_time;
  52
  53     current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
  54     if ((current_time - initial_time) >= msec) {
  55         msec = current_time - initial_time;
  56     } else {
  57         g_usleep((msec + initial_time - current_time) * 1000);
  58     }
  59
  60     return msec;
  61 }
  62
  63 static inline void record_dirtypages(DirtyPageRecord *dirty_pages,
  64                                      CPUState *cpu, bool start)
  65 {
  66     if (start) {
  67         dirty_pages[cpu->cpu_index].start_pages = cpu->dirty_pages;
  68     } else {
  69         dirty_pages[cpu->cpu_index].end_pages = cpu->dirty_pages;
  70     }
  71 }
  72
  73 static int64_t do_calculate_dirtyrate(DirtyPageRecord dirty_pages,
  74                                       int64_t calc_time_ms)
  75 {
  76     uint64_t memory_size_MB;
  77     uint64_t increased_dirty_pages =
  78         dirty_pages.end_pages - dirty_pages.start_pages;
  79
  80     memory_size_MB = (increased_dirty_pages * TARGET_PAGE_SIZE) >> 20;
  81
  82     return memory_size_MB * 1000 / calc_time_ms;
  83 }
  84
  85 void global_dirty_log_change(unsigned int flag, bool start)
  86 {
  87     qemu_mutex_lock_iothread();
  88     if (start) {
  89         memory_global_dirty_log_start(flag);
  90     } else {
  91         memory_global_dirty_log_stop(flag);
  92     }
  93     qemu_mutex_unlock_iothread();
  94 }
  95
  96 /*
  97  * global_dirty_log_sync
  98  * 1. sync dirty log from kvm
  99  * 2. stop dirty tracking if needed.
 100  */
 101 static void global_dirty_log_sync(unsigned int flag, bool one_shot)
 102 {
 103     qemu_mutex_lock_iothread();
 104     memory_global_dirty_log_sync();
 105     if (one_shot) {
 106         memory_global_dirty_log_stop(flag);
 107     }
 108     qemu_mutex_unlock_iothread();
 109 }
 110
 111 static DirtyPageRecord *vcpu_dirty_stat_alloc(VcpuStat *stat)
 112 {
 113     CPUState *cpu;
 114     DirtyPageRecord *records;
 115     int nvcpu = 0;
 116
 117     CPU_FOREACH(cpu) {
 118         nvcpu++;
 119     }
 120
 121     stat->nvcpu = nvcpu;
 122     stat->rates = g_new0(DirtyRateVcpu, nvcpu);
 123
 124     records = g_new0(DirtyPageRecord, nvcpu);
 125
 126     return records;
 127 }
 128
 129 static void vcpu_dirty_stat_collect(VcpuStat *stat,
 130                                     DirtyPageRecord *records,
 131                                     bool start)
 132 {
 133     CPUState *cpu;
 134
 135     CPU_FOREACH(cpu) {
 136         record_dirtypages(records, cpu, start);
 137     }
 138 }
 139
 140 int64_t vcpu_calculate_dirtyrate(int64_t calc_time_ms,
 141                                  VcpuStat *stat,
 142                                  unsigned int flag,
 143                                  bool one_shot)
 144 {
 145     DirtyPageRecord *records;
 146     int64_t init_time_ms;
 147     int64_t duration;
 148     int64_t dirtyrate;
 149     int i = 0;
 150     unsigned int gen_id;
 151
 152 retry:
 153     init_time_ms = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 154
 155     cpu_list_lock();
 156     gen_id = cpu_list_generation_id_get();
 157     records = vcpu_dirty_stat_alloc(stat);
 158     vcpu_dirty_stat_collect(stat, records, true);
 159     cpu_list_unlock();
 160
 161     duration = dirty_stat_wait(calc_time_ms, init_time_ms);
 162
 163     global_dirty_log_sync(flag, one_shot);
 164
 165     cpu_list_lock();
 166     if (gen_id != cpu_list_generation_id_get()) {
 167         g_free(records);
 168         g_free(stat->rates);
 169         cpu_list_unlock();
 170         goto retry;
 171     }
 172     vcpu_dirty_stat_collect(stat, records, false);
 173     cpu_list_unlock();
 174
 175     for (i = 0; i < stat->nvcpu; i++) {
 176         dirtyrate = do_calculate_dirtyrate(records[i], duration);
 177
 178         stat->rates[i].id = i;
 179         stat->rates[i].dirty_rate = dirtyrate;
 180
 181         trace_dirtyrate_do_calculate_vcpu(i, dirtyrate);
 182     }
 183
 184     g_free(records);
 185
 186     return duration;
 187 }
 188
 189 static bool is_sample_period_valid(int64_t sec)
 190 {
 191     if (sec < MIN_FETCH_DIRTYRATE_TIME_SEC ||
 192         sec > MAX_FETCH_DIRTYRATE_TIME_SEC) {
 193         return false;
 194     }
 195
 196     return true;
 197 }
 198
 199 static bool is_sample_pages_valid(int64_t pages)
 200 {
 201     return pages >= MIN_SAMPLE_PAGE_COUNT &&
 202            pages <= MAX_SAMPLE_PAGE_COUNT;
 203 }
 204
 205 static int dirtyrate_set_state(int *state, int old_state, int new_state)
 206 {
 207     assert(new_state < DIRTY_RATE_STATUS__MAX);
 208     trace_dirtyrate_set_state(DirtyRateStatus_str(new_state));
 209     if (qatomic_cmpxchg(state, old_state, new_state) == old_state) {
 210         return 0;
 211     } else {
 212         return -1;
 213     }
 214 }
 215
 216 static struct DirtyRateInfo *query_dirty_rate_info(void)
 217 {
 218     int i;
 219     int64_t dirty_rate = DirtyStat.dirty_rate;
 220     struct DirtyRateInfo *info = g_new0(DirtyRateInfo, 1);
 221     DirtyRateVcpuList *head = NULL, **tail = &head;
 222
 223     info->status = CalculatingState;
 224     info->start_time = DirtyStat.start_time;
 225     info->calc_time = DirtyStat.calc_time;
 226     info->sample_pages = DirtyStat.sample_pages;
 227     info->mode = dirtyrate_mode;
 228
 229     if (qatomic_read(&CalculatingState) == DIRTY_RATE_STATUS_MEASURED) {
 230         info->has_dirty_rate = true;
 231         info->dirty_rate = dirty_rate;
 232
 233         if (dirtyrate_mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 234             /*
 235              * set sample_pages with 0 to indicate page sampling
 236              * isn't enabled
 237              **/
 238             info->sample_pages = 0;
 239             info->has_vcpu_dirty_rate = true;
 240             for (i = 0; i < DirtyStat.dirty_ring.nvcpu; i++) {
 241                 DirtyRateVcpu *rate = g_new0(DirtyRateVcpu, 1);
 242                 rate->id = DirtyStat.dirty_ring.rates[i].id;
 243                 rate->dirty_rate = DirtyStat.dirty_ring.rates[i].dirty_rate;
 244                 QAPI_LIST_APPEND(tail, rate);
 245             }
 246             info->vcpu_dirty_rate = head;
 247         }
 248
 249         if (dirtyrate_mode == DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP) {
 250             info->sample_pages = 0;
 251         }
 252     }
 253
 254     trace_query_dirty_rate_info(DirtyRateStatus_str(CalculatingState));
 255
 256     return info;
 257 }
 258
 259 static void init_dirtyrate_stat(int64_t start_time,
 260                                 struct DirtyRateConfig config)
 261 {
 262     DirtyStat.dirty_rate = -1;
 263     DirtyStat.start_time = start_time;
 264     DirtyStat.calc_time = config.sample_period_seconds;
 265     DirtyStat.sample_pages = config.sample_pages_per_gigabytes;
 266
 267     switch (config.mode) {
 268     case DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING:
 269         DirtyStat.page_sampling.total_dirty_samples = 0;
 270         DirtyStat.page_sampling.total_sample_count = 0;
 271         DirtyStat.page_sampling.total_block_mem_MB = 0;
 272         break;
 273     case DIRTY_RATE_MEASURE_MODE_DIRTY_RING:
 274         DirtyStat.dirty_ring.nvcpu = -1;
 275         DirtyStat.dirty_ring.rates = NULL;
 276         break;
 277     default:
 278         break;
 279     }
 280 }
 281
 282 static void cleanup_dirtyrate_stat(struct DirtyRateConfig config)
 283 {
 284     /* last calc-dirty-rate qmp use dirty ring mode */
 285     if (dirtyrate_mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 286         free(DirtyStat.dirty_ring.rates);
 287         DirtyStat.dirty_ring.rates = NULL;
 288     }
 289 }
 290
 291 static void update_dirtyrate_stat(struct RamblockDirtyInfo *info)
 292 {
 293     DirtyStat.page_sampling.total_dirty_samples += info->sample_dirty_count;
 294     DirtyStat.page_sampling.total_sample_count += info->sample_pages_count;
 295     /* size of total pages in MB */
 296     DirtyStat.page_sampling.total_block_mem_MB += (info->ramblock_pages *
 297                                                    TARGET_PAGE_SIZE) >> 20;
 298 }
 299
 300 static void update_dirtyrate(uint64_t msec)
 301 {
 302     uint64_t dirtyrate;
 303     uint64_t total_dirty_samples = DirtyStat.page_sampling.total_dirty_samples;
 304     uint64_t total_sample_count = DirtyStat.page_sampling.total_sample_count;
 305     uint64_t total_block_mem_MB = DirtyStat.page_sampling.total_block_mem_MB;
 306
 307     dirtyrate = total_dirty_samples * total_block_mem_MB *
 308                 1000 / (total_sample_count * msec);
 309
 310     DirtyStat.dirty_rate = dirtyrate;
 311 }
 312
 313 /*
 314  * get hash result for the sampled memory with length of TARGET_PAGE_SIZE
 315  * in ramblock, which starts from ramblock base address.
 316  */
 317 static uint32_t get_ramblock_vfn_hash(struct RamblockDirtyInfo *info,
 318                                       uint64_t vfn)
 319 {
 320     uint32_t crc;
 321
 322     crc = crc32(0, (info->ramblock_addr +
 323                 vfn * TARGET_PAGE_SIZE), TARGET_PAGE_SIZE);
 324
 325     trace_get_ramblock_vfn_hash(info->idstr, vfn, crc);
 326     return crc;
 327 }
 328
 329 static bool save_ramblock_hash(struct RamblockDirtyInfo *info)
 330 {
 331     unsigned int sample_pages_count;
 332     int i;
 333     GRand *rand;
 334
 335     sample_pages_count = info->sample_pages_count;
 336
 337     /* ramblock size less than one page, return success to skip this ramblock */
 338     if (unlikely(info->ramblock_pages == 0 || sample_pages_count == 0)) {
 339         return true;
 340     }
 341
 342     info->hash_result = g_try_malloc0_n(sample_pages_count,
 343                                         sizeof(uint32_t));
 344     if (!info->hash_result) {
 345         return false;
 346     }
 347
 348     info->sample_page_vfn = g_try_malloc0_n(sample_pages_count,
 349                                             sizeof(uint64_t));
 350     if (!info->sample_page_vfn) {
 351         g_free(info->hash_result);
 352         return false;
 353     }
 354
 355     rand  = g_rand_new();
 356     for (i = 0; i < sample_pages_count; i++) {
 357         info->sample_page_vfn[i] = g_rand_int_range(rand, 0,
 358                                                     info->ramblock_pages - 1);
 359         info->hash_result[i] = get_ramblock_vfn_hash(info,
 360                                                      info->sample_page_vfn[i]);
 361     }
 362     g_rand_free(rand);
 363
 364     return true;
 365 }
 366
 367 static void get_ramblock_dirty_info(RAMBlock *block,
 368                                     struct RamblockDirtyInfo *info,
 369                                     struct DirtyRateConfig *config)
 370 {
 371     uint64_t sample_pages_per_gigabytes = config->sample_pages_per_gigabytes;
 372
 373     /* Right shift 30 bits to calc ramblock size in GB */
 374     info->sample_pages_count = (qemu_ram_get_used_length(block) *
 375                                 sample_pages_per_gigabytes) >> 30;
 376     /* Right shift TARGET_PAGE_BITS to calc page count */
 377     info->ramblock_pages = qemu_ram_get_used_length(block) >>
 378                            TARGET_PAGE_BITS;
 379     info->ramblock_addr = qemu_ram_get_host_addr(block);
 380     strcpy(info->idstr, qemu_ram_get_idstr(block));
 381 }
 382
 383 static void free_ramblock_dirty_info(struct RamblockDirtyInfo *infos, int count)
 384 {
 385     int i;
 386
 387     if (!infos) {
 388         return;
 389     }
 390
 391     for (i = 0; i < count; i++) {
 392         g_free(infos[i].sample_page_vfn);
 393         g_free(infos[i].hash_result);
 394     }
 395     g_free(infos);
 396 }
 397
 398 static bool skip_sample_ramblock(RAMBlock *block)
 399 {
 400     /*
 401      * Sample only blocks larger than MIN_RAMBLOCK_SIZE.
 402      */
 403     if (qemu_ram_get_used_length(block) < (MIN_RAMBLOCK_SIZE << 10)) {
 404         trace_skip_sample_ramblock(block->idstr,
 405                                    qemu_ram_get_used_length(block));
 406         return true;
 407     }
 408
 409     return false;
 410 }
 411
 412 static bool record_ramblock_hash_info(struct RamblockDirtyInfo **block_dinfo,
 413                                       struct DirtyRateConfig config,
 414                                       int *block_count)
 415 {
 416     struct RamblockDirtyInfo *info = NULL;
 417     struct RamblockDirtyInfo *dinfo = NULL;
 418     RAMBlock *block = NULL;
 419     int total_count = 0;
 420     int index = 0;
 421     bool ret = false;
 422
 423     RAMBLOCK_FOREACH_MIGRATABLE(block) {
 424         if (skip_sample_ramblock(block)) {
 425             continue;
 426         }
 427         total_count++;
 428     }
 429
 430     dinfo = g_try_malloc0_n(total_count, sizeof(struct RamblockDirtyInfo));
 431     if (dinfo == NULL) {
 432         goto out;
 433     }
 434
 435     RAMBLOCK_FOREACH_MIGRATABLE(block) {
 436         if (skip_sample_ramblock(block)) {
 437             continue;
 438         }
 439         if (index >= total_count) {
 440             break;
 441         }
 442         info = &dinfo[index];
 443         get_ramblock_dirty_info(block, info, &config);
 444         if (!save_ramblock_hash(info)) {
 445             goto out;
 446         }
 447         index++;
 448     }
 449     ret = true;
 450
 451 out:
 452     *block_count = index;
 453     *block_dinfo = dinfo;
 454     return ret;
 455 }
 456
 457 static void calc_page_dirty_rate(struct RamblockDirtyInfo *info)
 458 {
 459     uint32_t crc;
 460     int i;
 461
 462     for (i = 0; i < info->sample_pages_count; i++) {
 463         crc = get_ramblock_vfn_hash(info, info->sample_page_vfn[i]);
 464         if (crc != info->hash_result[i]) {
 465             trace_calc_page_dirty_rate(info->idstr, crc, info->hash_result[i]);
 466             info->sample_dirty_count++;
 467         }
 468     }
 469 }
 470
 471 static struct RamblockDirtyInfo *
 472 find_block_matched(RAMBlock *block, int count,
 473                   struct RamblockDirtyInfo *infos)
 474 {
 475     int i;
 476     struct RamblockDirtyInfo *matched;
 477
 478     for (i = 0; i < count; i++) {
 479         if (!strcmp(infos[i].idstr, qemu_ram_get_idstr(block))) {
 480             break;
 481         }
 482     }
 483
 484     if (i == count) {
 485         return NULL;
 486     }
 487
 488     if (infos[i].ramblock_addr != qemu_ram_get_host_addr(block) ||
 489         infos[i].ramblock_pages !=
 490             (qemu_ram_get_used_length(block) >> TARGET_PAGE_BITS)) {
 491         trace_find_page_matched(block->idstr);
 492         return NULL;
 493     }
 494
 495     matched = &infos[i];
 496
 497     return matched;
 498 }
 499
 500 static bool compare_page_hash_info(struct RamblockDirtyInfo *info,
 501                                   int block_count)
 502 {
 503     struct RamblockDirtyInfo *block_dinfo = NULL;
 504     RAMBlock *block = NULL;
 505
 506     RAMBLOCK_FOREACH_MIGRATABLE(block) {
 507         if (skip_sample_ramblock(block)) {
 508             continue;
 509         }
 510         block_dinfo = find_block_matched(block, block_count, info);
 511         if (block_dinfo == NULL) {
 512             continue;
 513         }
 514         calc_page_dirty_rate(block_dinfo);
 515         update_dirtyrate_stat(block_dinfo);
 516     }
 517
 518     if (DirtyStat.page_sampling.total_sample_count == 0) {
 519         return false;
 520     }
 521
 522     return true;
 523 }
 524
 525 static inline void record_dirtypages_bitmap(DirtyPageRecord *dirty_pages,
 526                                             bool start)
 527 {
 528     if (start) {
 529         dirty_pages->start_pages = total_dirty_pages;
 530     } else {
 531         dirty_pages->end_pages = total_dirty_pages;
 532     }
 533 }
 534
 535 static inline void dirtyrate_manual_reset_protect(void)
 536 {
 537     RAMBlock *block = NULL;
 538
 539     WITH_RCU_READ_LOCK_GUARD() {
 540         RAMBLOCK_FOREACH_MIGRATABLE(block) {
 541             memory_region_clear_dirty_bitmap(block->mr, 0,
 542                                              block->used_length);
 543         }
 544     }
 545 }
 546
 547 static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config)
 548 {
 549     int64_t msec = 0;
 550     int64_t start_time;
 551     DirtyPageRecord dirty_pages;
 552
 553     qemu_mutex_lock_iothread();
 554     memory_global_dirty_log_start(GLOBAL_DIRTY_DIRTY_RATE);
 555
 556     /*
 557      * 1'round of log sync may return all 1 bits with
 558      * KVM_DIRTY_LOG_INITIALLY_SET enable
 559      * skip it unconditionally and start dirty tracking
 560      * from 2'round of log sync
 561      */
 562     memory_global_dirty_log_sync();
 563
 564     /*
 565      * reset page protect manually and unconditionally.
 566      * this make sure kvm dirty log be cleared if
 567      * KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE cap is enabled.
 568      */
 569     dirtyrate_manual_reset_protect();
 570     qemu_mutex_unlock_iothread();
 571
 572     record_dirtypages_bitmap(&dirty_pages, true);
 573
 574     start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 575     DirtyStat.start_time = start_time / 1000;
 576
 577     msec = config.sample_period_seconds * 1000;
 578     msec = dirty_stat_wait(msec, start_time);
 579     DirtyStat.calc_time = msec / 1000;
 580
 581     /*
 582      * do two things.
 583      * 1. fetch dirty bitmap from kvm
 584      * 2. stop dirty tracking
 585      */
 586     global_dirty_log_sync(GLOBAL_DIRTY_DIRTY_RATE, true);
 587
 588     record_dirtypages_bitmap(&dirty_pages, false);
 589
 590     DirtyStat.dirty_rate = do_calculate_dirtyrate(dirty_pages, msec);
 591 }
 592
 593 static void calculate_dirtyrate_dirty_ring(struct DirtyRateConfig config)
 594 {
 595     int64_t duration;
 596     uint64_t dirtyrate = 0;
 597     uint64_t dirtyrate_sum = 0;
 598     int i = 0;
 599
 600     /* start log sync */
 601     global_dirty_log_change(GLOBAL_DIRTY_DIRTY_RATE, true);
 602
 603     DirtyStat.start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
 604
 605     /* calculate vcpu dirtyrate */
 606     duration = vcpu_calculate_dirtyrate(config.sample_period_seconds * 1000,
 607                                         &DirtyStat.dirty_ring,
 608                                         GLOBAL_DIRTY_DIRTY_RATE,
 609                                         true);
 610
 611     DirtyStat.calc_time = duration / 1000;
 612
 613     /* calculate vm dirtyrate */
 614     for (i = 0; i < DirtyStat.dirty_ring.nvcpu; i++) {
 615         dirtyrate = DirtyStat.dirty_ring.rates[i].dirty_rate;
 616         DirtyStat.dirty_ring.rates[i].dirty_rate = dirtyrate;
 617         dirtyrate_sum += dirtyrate;
 618     }
 619
 620     DirtyStat.dirty_rate = dirtyrate_sum;
 621 }
 622
 623 static void calculate_dirtyrate_sample_vm(struct DirtyRateConfig config)
 624 {
 625     struct RamblockDirtyInfo *block_dinfo = NULL;
 626     int block_count = 0;
 627     int64_t msec = 0;
 628     int64_t initial_time;
 629
 630     rcu_read_lock();
 631     initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 632     if (!record_ramblock_hash_info(&block_dinfo, config, &block_count)) {
 633         goto out;
 634     }
 635     rcu_read_unlock();
 636
 637     msec = config.sample_period_seconds * 1000;
 638     msec = dirty_stat_wait(msec, initial_time);
 639     DirtyStat.start_time = initial_time / 1000;
 640     DirtyStat.calc_time = msec / 1000;
 641
 642     rcu_read_lock();
 643     if (!compare_page_hash_info(block_dinfo, block_count)) {
 644         goto out;
 645     }
 646
 647     update_dirtyrate(msec);
 648
 649 out:
 650     rcu_read_unlock();
 651     free_ramblock_dirty_info(block_dinfo, block_count);
 652 }
 653
 654 static void calculate_dirtyrate(struct DirtyRateConfig config)
 655 {
 656     if (config.mode == DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP) {
 657         calculate_dirtyrate_dirty_bitmap(config);
 658     } else if (config.mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 659         calculate_dirtyrate_dirty_ring(config);
 660     } else {
 661         calculate_dirtyrate_sample_vm(config);
 662     }
 663
 664     trace_dirtyrate_calculate(DirtyStat.dirty_rate);
 665 }
 666
 667 void *get_dirtyrate_thread(void *arg)
 668 {
 669     struct DirtyRateConfig config = *(struct DirtyRateConfig *)arg;
 670     int ret;
 671     rcu_register_thread();
 672
 673     ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_UNSTARTED,
 674                               DIRTY_RATE_STATUS_MEASURING);
 675     if (ret == -1) {
 676         error_report("change dirtyrate state failed.");
 677         return NULL;
 678     }
 679
 680     calculate_dirtyrate(config);
 681
 682     ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_MEASURING,
 683                               DIRTY_RATE_STATUS_MEASURED);
 684     if (ret == -1) {
 685         error_report("change dirtyrate state failed.");
 686     }
 687
 688     rcu_unregister_thread();
 689     return NULL;
 690 }
 691
 692 void qmp_calc_dirty_rate(int64_t calc_time,
 693                          bool has_sample_pages,
 694                          int64_t sample_pages,
 695                          bool has_mode,
 696                          DirtyRateMeasureMode mode,
 697                          Error **errp)
 698 {
 699     static struct DirtyRateConfig config;
 700     QemuThread thread;
 701     int ret;
 702     int64_t start_time;
 703
 704     /*
 705      * If the dirty rate is already being measured, don't attempt to start.
 706      */
 707     if (qatomic_read(&CalculatingState) == DIRTY_RATE_STATUS_MEASURING) {
 708         error_setg(errp, "the dirty rate is already being measured.");
 709         return;
 710     }
 711
 712     if (!is_sample_period_valid(calc_time)) {
 713         error_setg(errp, "calc-time is out of range[%d, %d].",
 714                          MIN_FETCH_DIRTYRATE_TIME_SEC,
 715                          MAX_FETCH_DIRTYRATE_TIME_SEC);
 716         return;
 717     }
 718
 719     if (!has_mode) {
 720         mode =  DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING;
 721     }
 722
 723     if (has_sample_pages && mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) {
 724         error_setg(errp, "either sample-pages or dirty-ring can be specified.");
 725         return;
 726     }
 727
 728     if (has_sample_pages) {
 729         if (!is_sample_pages_valid(sample_pages)) {
 730             error_setg(errp, "sample-pages is out of range[%d, %d].",
 731                             MIN_SAMPLE_PAGE_COUNT,
 732                             MAX_SAMPLE_PAGE_COUNT);
 733             return;
 734         }
 735     } else {
 736         sample_pages = DIRTYRATE_DEFAULT_SAMPLE_PAGES;
 737     }
 738
 739     /*
 740      * dirty ring mode only works when kvm dirty ring is enabled.
 741      * on the contrary, dirty bitmap mode is not.
 742      */
 743     if (((mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) &&
 744         !kvm_dirty_ring_enabled()) ||
 745         ((mode == DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP) &&
 746          kvm_dirty_ring_enabled())) {
 747         error_setg(errp, "mode %s is not enabled, use other method instead.",
 748                          DirtyRateMeasureMode_str(mode));
 749          return;
 750     }
 751
 752     /*
 753      * Init calculation state as unstarted.
 754      */
 755     ret = dirtyrate_set_state(&CalculatingState, CalculatingState,
 756                               DIRTY_RATE_STATUS_UNSTARTED);
 757     if (ret == -1) {
 758         error_setg(errp, "init dirty rate calculation state failed.");
 759         return;
 760     }
 761
 762     config.sample_period_seconds = calc_time;
 763     config.sample_pages_per_gigabytes = sample_pages;
 764     config.mode = mode;
 765
 766     cleanup_dirtyrate_stat(config);
 767
 768     /*
 769      * update dirty rate mode so that we can figure out what mode has
 770      * been used in last calculation
 771      **/
 772     dirtyrate_mode = mode;
 773
 774     start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
 775     init_dirtyrate_stat(start_time, config);
 776
 777     qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread,
 778                        (void *)&config, QEMU_THREAD_DETACHED);
 779 }
 780
 781 struct DirtyRateInfo *qmp_query_dirty_rate(Error **errp)
 782 {
 783     return query_dirty_rate_info();
 784 }
 785
 786 void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict)
 787 {
 788     DirtyRateInfo *info = query_dirty_rate_info();
 789
 790     monitor_printf(mon, "Status: %s\n",
 791                    DirtyRateStatus_str(info->status));
 792     monitor_printf(mon, "Start Time: %"PRIi64" (ms)\n",
 793                    info->start_time);
 794     monitor_printf(mon, "Sample Pages: %"PRIu64" (per GB)\n",
 795                    info->sample_pages);
 796     monitor_printf(mon, "Period: %"PRIi64" (sec)\n",
 797                    info->calc_time);
 798     monitor_printf(mon, "Mode: %s\n",
 799                    DirtyRateMeasureMode_str(info->mode));
 800     monitor_printf(mon, "Dirty rate: ");
 801     if (info->has_dirty_rate) {
 802         monitor_printf(mon, "%"PRIi64" (MB/s)\n", info->dirty_rate);
 803         if (info->has_vcpu_dirty_rate) {
 804             DirtyRateVcpuList *rate, *head = info->vcpu_dirty_rate;
 805             for (rate = head; rate != NULL; rate = rate->next) {
 806                 monitor_printf(mon, "vcpu[%"PRIi64"], Dirty rate: %"PRIi64
 807                                " (MB/s)\n", rate->value->id,
 808                                rate->value->dirty_rate);
 809             }
 810         }
 811     } else {
 812         monitor_printf(mon, "(not ready)\n");
 813     }
 814
 815     qapi_free_DirtyRateVcpuList(info->vcpu_dirty_rate);
 816     g_free(info);
 817 }
 818
 819 void hmp_calc_dirty_rate(Monitor *mon, const QDict *qdict)
 820 {
 821     int64_t sec = qdict_get_try_int(qdict, "second", 0);
 822     int64_t sample_pages = qdict_get_try_int(qdict, "sample_pages_per_GB", -1);
 823     bool has_sample_pages = (sample_pages != -1);
 824     bool dirty_ring = qdict_get_try_bool(qdict, "dirty_ring", false);
 825     bool dirty_bitmap = qdict_get_try_bool(qdict, "dirty_bitmap", false);
 826     DirtyRateMeasureMode mode = DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING;
 827     Error *err = NULL;
 828
 829     if (!sec) {
 830         monitor_printf(mon, "Incorrect period length specified!\n");
 831         return;
 832     }
 833
 834     if (dirty_ring && dirty_bitmap) {
 835         monitor_printf(mon, "Either dirty ring or dirty bitmap "
 836                        "can be specified!\n");
 837         return;
 838     }
 839
 840     if (dirty_bitmap) {
 841         mode = DIRTY_RATE_MEASURE_MODE_DIRTY_BITMAP;
 842     } else if (dirty_ring) {
 843         mode = DIRTY_RATE_MEASURE_MODE_DIRTY_RING;
 844     }
 845
 846     qmp_calc_dirty_rate(sec, has_sample_pages, sample_pages, true,
 847                         mode, &err);
 848     if (err) {
 849         hmp_handle_error(mon, err);
 850         return;
 851     }
 852
 853     monitor_printf(mon, "Starting dirty rate measurement with period %"PRIi64
 854                    " seconds\n", sec);
 855     monitor_printf(mon, "[Please use 'info dirty_rate' to check results]\n");
 856 }