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