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