migration.c

   1 /*
   2  * QEMU live migration
   3  *
   4  * Copyright IBM, Corp. 2008
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  * Contributions after 2012-01-13 are licensed under the terms of the
  13  * GNU GPL, version 2 or (at your option) any later version.
  14  */
  15
  16 #include "qemu-common.h"
  17 #include "qemu/main-loop.h"
  18 #include "migration/migration.h"
  19 #include "monitor/monitor.h"
  20 #include "migration/qemu-file.h"
  21 #include "sysemu/sysemu.h"
  22 #include "block/block.h"
  23 #include "qemu/sockets.h"
  24 #include "migration/block.h"
  25 #include "qemu/thread.h"
  26 #include "qmp-commands.h"
  27 #include "trace.h"
  28
  29 enum {
  30     MIG_STATE_ERROR = -1,
  31     MIG_STATE_NONE,
  32     MIG_STATE_SETUP,
  33     MIG_STATE_CANCELLING,
  34     MIG_STATE_CANCELLED,
  35     MIG_STATE_ACTIVE,
  36     MIG_STATE_COMPLETED,
  37 };
  38
  39 #define MAX_THROTTLE  (32 << 20)      /* Migration speed throttling */
  40
  41 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
  42  * data. */
  43 #define BUFFER_DELAY     100
  44 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
  45
  46 /* Migration XBZRLE default cache size */
  47 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
  48
  49 static NotifierList migration_state_notifiers =
  50     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
  51
  52 /* When we add fault tolerance, we could have several
  53    migrations at once.  For now we don't need to add
  54    dynamic creation of migration */
  55
  56 MigrationState *migrate_get_current(void)
  57 {
  58     static MigrationState current_migration = {
  59         .state = MIG_STATE_NONE,
  60         .bandwidth_limit = MAX_THROTTLE,
  61         .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
  62         .mbps = -1,
  63     };
  64
  65     return &current_migration;
  66 }
  67
  68 void qemu_start_incoming_migration(const char *uri, Error **errp)
  69 {
  70     const char *p;
  71
  72     if (strstart(uri, "tcp:", &p))
  73         tcp_start_incoming_migration(p, errp);
  74 #ifdef CONFIG_RDMA
  75     else if (strstart(uri, "rdma:", &p))
  76         rdma_start_incoming_migration(p, errp);
  77 #endif
  78 #if !defined(WIN32)
  79     else if (strstart(uri, "exec:", &p))
  80         exec_start_incoming_migration(p, errp);
  81     else if (strstart(uri, "unix:", &p))
  82         unix_start_incoming_migration(p, errp);
  83     else if (strstart(uri, "fd:", &p))
  84         fd_start_incoming_migration(p, errp);
  85 #endif
  86     else {
  87         error_setg(errp, "unknown migration protocol: %s", uri);
  88     }
  89 }
  90
  91 static void process_incoming_migration_co(void *opaque)
  92 {
  93     QEMUFile *f = opaque;
  94     Error *local_err = NULL;
  95     int ret;
  96
  97     ret = qemu_loadvm_state(f);
  98     qemu_fclose(f);
  99     free_xbzrle_decoded_buf();
 100     if (ret < 0) {
 101         error_report("load of migration failed: %s", strerror(-ret));
 102         exit(EXIT_FAILURE);
 103     }
 104     qemu_announce_self();
 105
 106     /* Make sure all file formats flush their mutable metadata */
 107     bdrv_invalidate_cache_all(&local_err);
 108     if (local_err) {
 109         qerror_report_err(local_err);
 110         error_free(local_err);
 111         exit(EXIT_FAILURE);
 112     }
 113
 114     if (autostart) {
 115         vm_start();
 116     } else {
 117         runstate_set(RUN_STATE_PAUSED);
 118     }
 119 }
 120
 121 void process_incoming_migration(QEMUFile *f)
 122 {
 123     Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
 124     int fd = qemu_get_fd(f);
 125
 126     assert(fd != -1);
 127     qemu_set_nonblock(fd);
 128     qemu_coroutine_enter(co, f);
 129 }
 130
 131 /* amount of nanoseconds we are willing to wait for migration to be down.
 132  * the choice of nanoseconds is because it is the maximum resolution that
 133  * get_clock() can achieve. It is an internal measure. All user-visible
 134  * units must be in seconds */
 135 static uint64_t max_downtime = 300000000;
 136
 137 uint64_t migrate_max_downtime(void)
 138 {
 139     return max_downtime;
 140 }
 141
 142 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
 143 {
 144     MigrationCapabilityStatusList *head = NULL;
 145     MigrationCapabilityStatusList *caps;
 146     MigrationState *s = migrate_get_current();
 147     int i;
 148
 149     caps = NULL; /* silence compiler warning */
 150     for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
 151         if (head == NULL) {
 152             head = g_malloc0(sizeof(*caps));
 153             caps = head;
 154         } else {
 155             caps->next = g_malloc0(sizeof(*caps));
 156             caps = caps->next;
 157         }
 158         caps->value =
 159             g_malloc(sizeof(*caps->value));
 160         caps->value->capability = i;
 161         caps->value->state = s->enabled_capabilities[i];
 162     }
 163
 164     return head;
 165 }
 166
 167 static void get_xbzrle_cache_stats(MigrationInfo *info)
 168 {
 169     if (migrate_use_xbzrle()) {
 170         info->has_xbzrle_cache = true;
 171         info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
 172         info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
 173         info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
 174         info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
 175         info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
 176         info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate();
 177         info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
 178     }
 179 }
 180
 181 MigrationInfo *qmp_query_migrate(Error **errp)
 182 {
 183     MigrationInfo *info = g_malloc0(sizeof(*info));
 184     MigrationState *s = migrate_get_current();
 185
 186     switch (s->state) {
 187     case MIG_STATE_NONE:
 188         /* no migration has happened ever */
 189         break;
 190     case MIG_STATE_SETUP:
 191         info->has_status = true;
 192         info->status = g_strdup("setup");
 193         info->has_total_time = false;
 194         break;
 195     case MIG_STATE_ACTIVE:
 196     case MIG_STATE_CANCELLING:
 197         info->has_status = true;
 198         info->status = g_strdup("active");
 199         info->has_total_time = true;
 200         info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
 201             - s->total_time;
 202         info->has_expected_downtime = true;
 203         info->expected_downtime = s->expected_downtime;
 204         info->has_setup_time = true;
 205         info->setup_time = s->setup_time;
 206
 207         info->has_ram = true;
 208         info->ram = g_malloc0(sizeof(*info->ram));
 209         info->ram->transferred = ram_bytes_transferred();
 210         info->ram->remaining = ram_bytes_remaining();
 211         info->ram->total = ram_bytes_total();
 212         info->ram->duplicate = dup_mig_pages_transferred();
 213         info->ram->skipped = skipped_mig_pages_transferred();
 214         info->ram->normal = norm_mig_pages_transferred();
 215         info->ram->normal_bytes = norm_mig_bytes_transferred();
 216         info->ram->dirty_pages_rate = s->dirty_pages_rate;
 217         info->ram->mbps = s->mbps;
 218         info->ram->dirty_sync_count = s->dirty_sync_count;
 219
 220         if (blk_mig_active()) {
 221             info->has_disk = true;
 222             info->disk = g_malloc0(sizeof(*info->disk));
 223             info->disk->transferred = blk_mig_bytes_transferred();
 224             info->disk->remaining = blk_mig_bytes_remaining();
 225             info->disk->total = blk_mig_bytes_total();
 226         }
 227
 228         get_xbzrle_cache_stats(info);
 229         break;
 230     case MIG_STATE_COMPLETED:
 231         get_xbzrle_cache_stats(info);
 232
 233         info->has_status = true;
 234         info->status = g_strdup("completed");
 235         info->has_total_time = true;
 236         info->total_time = s->total_time;
 237         info->has_downtime = true;
 238         info->downtime = s->downtime;
 239         info->has_setup_time = true;
 240         info->setup_time = s->setup_time;
 241
 242         info->has_ram = true;
 243         info->ram = g_malloc0(sizeof(*info->ram));
 244         info->ram->transferred = ram_bytes_transferred();
 245         info->ram->remaining = 0;
 246         info->ram->total = ram_bytes_total();
 247         info->ram->duplicate = dup_mig_pages_transferred();
 248         info->ram->skipped = skipped_mig_pages_transferred();
 249         info->ram->normal = norm_mig_pages_transferred();
 250         info->ram->normal_bytes = norm_mig_bytes_transferred();
 251         info->ram->mbps = s->mbps;
 252         info->ram->dirty_sync_count = s->dirty_sync_count;
 253         break;
 254     case MIG_STATE_ERROR:
 255         info->has_status = true;
 256         info->status = g_strdup("failed");
 257         break;
 258     case MIG_STATE_CANCELLED:
 259         info->has_status = true;
 260         info->status = g_strdup("cancelled");
 261         break;
 262     }
 263
 264     return info;
 265 }
 266
 267 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
 268                                   Error **errp)
 269 {
 270     MigrationState *s = migrate_get_current();
 271     MigrationCapabilityStatusList *cap;
 272
 273     if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) {
 274         error_set(errp, QERR_MIGRATION_ACTIVE);
 275         return;
 276     }
 277
 278     for (cap = params; cap; cap = cap->next) {
 279         s->enabled_capabilities[cap->value->capability] = cap->value->state;
 280     }
 281 }
 282
 283 /* shared migration helpers */
 284
 285 static void migrate_set_state(MigrationState *s, int old_state, int new_state)
 286 {
 287     if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) {
 288         trace_migrate_set_state(new_state);
 289     }
 290 }
 291
 292 static void migrate_fd_cleanup(void *opaque)
 293 {
 294     MigrationState *s = opaque;
 295
 296     qemu_bh_delete(s->cleanup_bh);
 297     s->cleanup_bh = NULL;
 298
 299     if (s->file) {
 300         trace_migrate_fd_cleanup();
 301         qemu_mutex_unlock_iothread();
 302         qemu_thread_join(&s->thread);
 303         qemu_mutex_lock_iothread();
 304
 305         qemu_fclose(s->file);
 306         s->file = NULL;
 307     }
 308
 309     assert(s->state != MIG_STATE_ACTIVE);
 310
 311     if (s->state != MIG_STATE_COMPLETED) {
 312         qemu_savevm_state_cancel();
 313         if (s->state == MIG_STATE_CANCELLING) {
 314             migrate_set_state(s, MIG_STATE_CANCELLING, MIG_STATE_CANCELLED);
 315         }
 316     }
 317
 318     notifier_list_notify(&migration_state_notifiers, s);
 319 }
 320
 321 void migrate_fd_error(MigrationState *s)
 322 {
 323     trace_migrate_fd_error();
 324     assert(s->file == NULL);
 325     s->state = MIG_STATE_ERROR;
 326     trace_migrate_set_state(MIG_STATE_ERROR);
 327     notifier_list_notify(&migration_state_notifiers, s);
 328 }
 329
 330 static void migrate_fd_cancel(MigrationState *s)
 331 {
 332     int old_state ;
 333     trace_migrate_fd_cancel();
 334
 335     do {
 336         old_state = s->state;
 337         if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE) {
 338             break;
 339         }
 340         migrate_set_state(s, old_state, MIG_STATE_CANCELLING);
 341     } while (s->state != MIG_STATE_CANCELLING);
 342 }
 343
 344 void add_migration_state_change_notifier(Notifier *notify)
 345 {
 346     notifier_list_add(&migration_state_notifiers, notify);
 347 }
 348
 349 void remove_migration_state_change_notifier(Notifier *notify)
 350 {
 351     notifier_remove(notify);
 352 }
 353
 354 bool migration_in_setup(MigrationState *s)
 355 {
 356     return s->state == MIG_STATE_SETUP;
 357 }
 358
 359 bool migration_has_finished(MigrationState *s)
 360 {
 361     return s->state == MIG_STATE_COMPLETED;
 362 }
 363
 364 bool migration_has_failed(MigrationState *s)
 365 {
 366     return (s->state == MIG_STATE_CANCELLED ||
 367             s->state == MIG_STATE_ERROR);
 368 }
 369
 370 static MigrationState *migrate_init(const MigrationParams *params)
 371 {
 372     MigrationState *s = migrate_get_current();
 373     int64_t bandwidth_limit = s->bandwidth_limit;
 374     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
 375     int64_t xbzrle_cache_size = s->xbzrle_cache_size;
 376
 377     memcpy(enabled_capabilities, s->enabled_capabilities,
 378            sizeof(enabled_capabilities));
 379
 380     memset(s, 0, sizeof(*s));
 381     s->params = *params;
 382     memcpy(s->enabled_capabilities, enabled_capabilities,
 383            sizeof(enabled_capabilities));
 384     s->xbzrle_cache_size = xbzrle_cache_size;
 385
 386     s->bandwidth_limit = bandwidth_limit;
 387     s->state = MIG_STATE_SETUP;
 388     trace_migrate_set_state(MIG_STATE_SETUP);
 389
 390     s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 391     return s;
 392 }
 393
 394 static GSList *migration_blockers;
 395
 396 void migrate_add_blocker(Error *reason)
 397 {
 398     migration_blockers = g_slist_prepend(migration_blockers, reason);
 399 }
 400
 401 void migrate_del_blocker(Error *reason)
 402 {
 403     migration_blockers = g_slist_remove(migration_blockers, reason);
 404 }
 405
 406 void qmp_migrate(const char *uri, bool has_blk, bool blk,
 407                  bool has_inc, bool inc, bool has_detach, bool detach,
 408                  Error **errp)
 409 {
 410     Error *local_err = NULL;
 411     MigrationState *s = migrate_get_current();
 412     MigrationParams params;
 413     const char *p;
 414
 415     params.blk = has_blk && blk;
 416     params.shared = has_inc && inc;
 417
 418     if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP ||
 419         s->state == MIG_STATE_CANCELLING) {
 420         error_set(errp, QERR_MIGRATION_ACTIVE);
 421         return;
 422     }
 423
 424     if (runstate_check(RUN_STATE_INMIGRATE)) {
 425         error_setg(errp, "Guest is waiting for an incoming migration");
 426         return;
 427     }
 428
 429     if (qemu_savevm_state_blocked(errp)) {
 430         return;
 431     }
 432
 433     if (migration_blockers) {
 434         *errp = error_copy(migration_blockers->data);
 435         return;
 436     }
 437
 438     s = migrate_init(&params);
 439
 440     if (strstart(uri, "tcp:", &p)) {
 441         tcp_start_outgoing_migration(s, p, &local_err);
 442 #ifdef CONFIG_RDMA
 443     } else if (strstart(uri, "rdma:", &p)) {
 444         rdma_start_outgoing_migration(s, p, &local_err);
 445 #endif
 446 #if !defined(WIN32)
 447     } else if (strstart(uri, "exec:", &p)) {
 448         exec_start_outgoing_migration(s, p, &local_err);
 449     } else if (strstart(uri, "unix:", &p)) {
 450         unix_start_outgoing_migration(s, p, &local_err);
 451     } else if (strstart(uri, "fd:", &p)) {
 452         fd_start_outgoing_migration(s, p, &local_err);
 453 #endif
 454     } else {
 455         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol");
 456         s->state = MIG_STATE_ERROR;
 457         return;
 458     }
 459
 460     if (local_err) {
 461         migrate_fd_error(s);
 462         error_propagate(errp, local_err);
 463         return;
 464     }
 465 }
 466
 467 void qmp_migrate_cancel(Error **errp)
 468 {
 469     migrate_fd_cancel(migrate_get_current());
 470 }
 471
 472 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
 473 {
 474     MigrationState *s = migrate_get_current();
 475     int64_t new_size;
 476
 477     /* Check for truncation */
 478     if (value != (size_t)value) {
 479         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 480                   "exceeding address space");
 481         return;
 482     }
 483
 484     /* Cache should not be larger than guest ram size */
 485     if (value > ram_bytes_total()) {
 486         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 487                   "exceeds guest ram size ");
 488         return;
 489     }
 490
 491     new_size = xbzrle_cache_resize(value);
 492     if (new_size < 0) {
 493         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 494                   "is smaller than page size");
 495         return;
 496     }
 497
 498     s->xbzrle_cache_size = new_size;
 499 }
 500
 501 int64_t qmp_query_migrate_cache_size(Error **errp)
 502 {
 503     return migrate_xbzrle_cache_size();
 504 }
 505
 506 void qmp_migrate_set_speed(int64_t value, Error **errp)
 507 {
 508     MigrationState *s;
 509
 510     if (value < 0) {
 511         value = 0;
 512     }
 513     if (value > SIZE_MAX) {
 514         value = SIZE_MAX;
 515     }
 516
 517     s = migrate_get_current();
 518     s->bandwidth_limit = value;
 519     if (s->file) {
 520         qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO);
 521     }
 522 }
 523
 524 void qmp_migrate_set_downtime(double value, Error **errp)
 525 {
 526     value *= 1e9;
 527     value = MAX(0, MIN(UINT64_MAX, value));
 528     max_downtime = (uint64_t)value;
 529 }
 530
 531 bool migrate_rdma_pin_all(void)
 532 {
 533     MigrationState *s;
 534
 535     s = migrate_get_current();
 536
 537     return s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL];
 538 }
 539
 540 bool migrate_auto_converge(void)
 541 {
 542     MigrationState *s;
 543
 544     s = migrate_get_current();
 545
 546     return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
 547 }
 548
 549 bool migrate_zero_blocks(void)
 550 {
 551     MigrationState *s;
 552
 553     s = migrate_get_current();
 554
 555     return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
 556 }
 557
 558 int migrate_use_xbzrle(void)
 559 {
 560     MigrationState *s;
 561
 562     s = migrate_get_current();
 563
 564     return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
 565 }
 566
 567 int64_t migrate_xbzrle_cache_size(void)
 568 {
 569     MigrationState *s;
 570
 571     s = migrate_get_current();
 572
 573     return s->xbzrle_cache_size;
 574 }
 575
 576 /* migration thread support */
 577
 578 static void *migration_thread(void *opaque)
 579 {
 580     MigrationState *s = opaque;
 581     int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 582     int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 583     int64_t initial_bytes = 0;
 584     int64_t max_size = 0;
 585     int64_t start_time = initial_time;
 586     bool old_vm_running = false;
 587
 588     qemu_savevm_state_begin(s->file, &s->params);
 589
 590     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
 591     migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE);
 592
 593     while (s->state == MIG_STATE_ACTIVE) {
 594         int64_t current_time;
 595         uint64_t pending_size;
 596
 597         if (!qemu_file_rate_limit(s->file)) {
 598             pending_size = qemu_savevm_state_pending(s->file, max_size);
 599             trace_migrate_pending(pending_size, max_size);
 600             if (pending_size && pending_size >= max_size) {
 601                 qemu_savevm_state_iterate(s->file);
 602             } else {
 603                 int ret;
 604
 605                 qemu_mutex_lock_iothread();
 606                 start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 607                 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
 608                 old_vm_running = runstate_is_running();
 609
 610                 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
 611                 if (ret >= 0) {
 612                     qemu_file_set_rate_limit(s->file, INT64_MAX);
 613                     qemu_savevm_state_complete(s->file);
 614                 }
 615                 qemu_mutex_unlock_iothread();
 616
 617                 if (ret < 0) {
 618                     migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
 619                     break;
 620                 }
 621
 622                 if (!qemu_file_get_error(s->file)) {
 623                     migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);
 624                     break;
 625                 }
 626             }
 627         }
 628
 629         if (qemu_file_get_error(s->file)) {
 630             migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
 631             break;
 632         }
 633         current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 634         if (current_time >= initial_time + BUFFER_DELAY) {
 635             uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;
 636             uint64_t time_spent = current_time - initial_time;
 637             double bandwidth = transferred_bytes / time_spent;
 638             max_size = bandwidth * migrate_max_downtime() / 1000000;
 639
 640             s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
 641                     ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
 642
 643             trace_migrate_transferred(transferred_bytes, time_spent,
 644                                       bandwidth, max_size);
 645             /* if we haven't sent anything, we don't want to recalculate
 646                10000 is a small enough number for our purposes */
 647             if (s->dirty_bytes_rate && transferred_bytes > 10000) {
 648                 s->expected_downtime = s->dirty_bytes_rate / bandwidth;
 649             }
 650
 651             qemu_file_reset_rate_limit(s->file);
 652             initial_time = current_time;
 653             initial_bytes = qemu_ftell(s->file);
 654         }
 655         if (qemu_file_rate_limit(s->file)) {
 656             /* usleep expects microseconds */
 657             g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
 658         }
 659     }
 660
 661     qemu_mutex_lock_iothread();
 662     if (s->state == MIG_STATE_COMPLETED) {
 663         int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 664         uint64_t transferred_bytes = qemu_ftell(s->file);
 665         s->total_time = end_time - s->total_time;
 666         s->downtime = end_time - start_time;
 667         if (s->total_time) {
 668             s->mbps = (((double) transferred_bytes * 8.0) /
 669                        ((double) s->total_time)) / 1000;
 670         }
 671         runstate_set(RUN_STATE_POSTMIGRATE);
 672     } else {
 673         if (old_vm_running) {
 674             vm_start();
 675         }
 676     }
 677     qemu_bh_schedule(s->cleanup_bh);
 678     qemu_mutex_unlock_iothread();
 679
 680     return NULL;
 681 }
 682
 683 void migrate_fd_connect(MigrationState *s)
 684 {
 685     s->state = MIG_STATE_SETUP;
 686     trace_migrate_set_state(MIG_STATE_SETUP);
 687
 688     /* This is a best 1st approximation. ns to ms */
 689     s->expected_downtime = max_downtime/1000000;
 690     s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
 691
 692     qemu_file_set_rate_limit(s->file,
 693                              s->bandwidth_limit / XFER_LIMIT_RATIO);
 694
 695     /* Notify before starting migration thread */
 696     notifier_list_notify(&migration_state_notifiers, s);
 697
 698     qemu_thread_create(&s->thread, "migration", migration_thread, s,
 699                        QEMU_THREAD_JOINABLE);
 700 }