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 //#define DEBUG_MIGRATION
  30
  31 #ifdef DEBUG_MIGRATION
  32 #define DPRINTF(fmt, ...) \
  33     do { printf("migration: " fmt, ## __VA_ARGS__); } while (0)
  34 #else
  35 #define DPRINTF(fmt, ...) \
  36     do { } while (0)
  37 #endif
  38
  39 enum {
  40     MIG_STATE_ERROR = -1,
  41     MIG_STATE_NONE,
  42     MIG_STATE_SETUP,
  43     MIG_STATE_CANCELLING,
  44     MIG_STATE_CANCELLED,
  45     MIG_STATE_ACTIVE,
  46     MIG_STATE_COMPLETED,
  47 };
  48
  49 #define MAX_THROTTLE  (32 << 20)      /* Migration speed throttling */
  50
  51 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
  52  * data. */
  53 #define BUFFER_DELAY     100
  54 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
  55
  56 /* Migration XBZRLE default cache size */
  57 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
  58
  59 static NotifierList migration_state_notifiers =
  60     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
  61
  62 /* When we add fault tolerance, we could have several
  63    migrations at once.  For now we don't need to add
  64    dynamic creation of migration */
  65
  66 MigrationState *migrate_get_current(void)
  67 {
  68     static MigrationState current_migration = {
  69         .state = MIG_STATE_NONE,
  70         .bandwidth_limit = MAX_THROTTLE,
  71         .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
  72         .mbps = -1,
  73     };
  74
  75     return &current_migration;
  76 }
  77
  78 void qemu_start_incoming_migration(const char *uri, Error **errp)
  79 {
  80     const char *p;
  81
  82     if (strstart(uri, "tcp:", &p))
  83         tcp_start_incoming_migration(p, errp);
  84 #ifdef CONFIG_RDMA
  85     else if (strstart(uri, "rdma:", &p))
  86         rdma_start_incoming_migration(p, errp);
  87 #endif
  88 #if !defined(WIN32)
  89     else if (strstart(uri, "exec:", &p))
  90         exec_start_incoming_migration(p, errp);
  91     else if (strstart(uri, "unix:", &p))
  92         unix_start_incoming_migration(p, errp);
  93     else if (strstart(uri, "fd:", &p))
  94         fd_start_incoming_migration(p, errp);
  95 #endif
  96     else {
  97         error_setg(errp, "unknown migration protocol: %s", uri);
  98     }
  99 }
 100
 101 static void process_incoming_migration_co(void *opaque)
 102 {
 103     QEMUFile *f = opaque;
 104     Error *local_err = NULL;
 105     int ret;
 106
 107     ret = qemu_loadvm_state(f);
 108     qemu_fclose(f);
 109     free_xbzrle_decoded_buf();
 110     if (ret < 0) {
 111         fprintf(stderr, "load of migration failed\n");
 112         exit(EXIT_FAILURE);
 113     }
 114     qemu_announce_self();
 115     DPRINTF("successfully loaded vm state\n");
 116
 117     bdrv_clear_incoming_migration_all();
 118     /* Make sure all file formats flush their mutable metadata */
 119     bdrv_invalidate_cache_all(&local_err);
 120     if (local_err) {
 121         qerror_report_err(local_err);
 122         error_free(local_err);
 123         exit(EXIT_FAILURE);
 124     }
 125
 126     if (autostart) {
 127         vm_start();
 128     } else {
 129         runstate_set(RUN_STATE_PAUSED);
 130     }
 131 }
 132
 133 void process_incoming_migration(QEMUFile *f)
 134 {
 135     Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
 136     int fd = qemu_get_fd(f);
 137
 138     assert(fd != -1);
 139     qemu_set_nonblock(fd);
 140     qemu_coroutine_enter(co, f);
 141 }
 142
 143 /* amount of nanoseconds we are willing to wait for migration to be down.
 144  * the choice of nanoseconds is because it is the maximum resolution that
 145  * get_clock() can achieve. It is an internal measure. All user-visible
 146  * units must be in seconds */
 147 static uint64_t max_downtime = 30000000;
 148
 149 uint64_t migrate_max_downtime(void)
 150 {
 151     return max_downtime;
 152 }
 153
 154 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
 155 {
 156     MigrationCapabilityStatusList *head = NULL;
 157     MigrationCapabilityStatusList *caps;
 158     MigrationState *s = migrate_get_current();
 159     int i;
 160
 161     caps = NULL; /* silence compiler warning */
 162     for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
 163         if (head == NULL) {
 164             head = g_malloc0(sizeof(*caps));
 165             caps = head;
 166         } else {
 167             caps->next = g_malloc0(sizeof(*caps));
 168             caps = caps->next;
 169         }
 170         caps->value =
 171             g_malloc(sizeof(*caps->value));
 172         caps->value->capability = i;
 173         caps->value->state = s->enabled_capabilities[i];
 174     }
 175
 176     return head;
 177 }
 178
 179 static void get_xbzrle_cache_stats(MigrationInfo *info)
 180 {
 181     if (migrate_use_xbzrle()) {
 182         info->has_xbzrle_cache = true;
 183         info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
 184         info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
 185         info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
 186         info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
 187         info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
 188         info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
 189     }
 190 }
 191
 192 MigrationInfo *qmp_query_migrate(Error **errp)
 193 {
 194     MigrationInfo *info = g_malloc0(sizeof(*info));
 195     MigrationState *s = migrate_get_current();
 196
 197     switch (s->state) {
 198     case MIG_STATE_NONE:
 199         /* no migration has happened ever */
 200         break;
 201     case MIG_STATE_SETUP:
 202         info->has_status = true;
 203         info->status = g_strdup("setup");
 204         info->has_total_time = false;
 205         break;
 206     case MIG_STATE_ACTIVE:
 207     case MIG_STATE_CANCELLING:
 208         info->has_status = true;
 209         info->status = g_strdup("active");
 210         info->has_total_time = true;
 211         info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
 212             - s->total_time;
 213         info->has_expected_downtime = true;
 214         info->expected_downtime = s->expected_downtime;
 215         info->has_setup_time = true;
 216         info->setup_time = s->setup_time;
 217
 218         info->has_ram = true;
 219         info->ram = g_malloc0(sizeof(*info->ram));
 220         info->ram->transferred = ram_bytes_transferred();
 221         info->ram->remaining = ram_bytes_remaining();
 222         info->ram->total = ram_bytes_total();
 223         info->ram->duplicate = dup_mig_pages_transferred();
 224         info->ram->skipped = skipped_mig_pages_transferred();
 225         info->ram->normal = norm_mig_pages_transferred();
 226         info->ram->normal_bytes = norm_mig_bytes_transferred();
 227         info->ram->dirty_pages_rate = s->dirty_pages_rate;
 228         info->ram->mbps = s->mbps;
 229
 230         if (blk_mig_active()) {
 231             info->has_disk = true;
 232             info->disk = g_malloc0(sizeof(*info->disk));
 233             info->disk->transferred = blk_mig_bytes_transferred();
 234             info->disk->remaining = blk_mig_bytes_remaining();
 235             info->disk->total = blk_mig_bytes_total();
 236         }
 237
 238         get_xbzrle_cache_stats(info);
 239         break;
 240     case MIG_STATE_COMPLETED:
 241         get_xbzrle_cache_stats(info);
 242
 243         info->has_status = true;
 244         info->status = g_strdup("completed");
 245         info->has_total_time = true;
 246         info->total_time = s->total_time;
 247         info->has_downtime = true;
 248         info->downtime = s->downtime;
 249         info->has_setup_time = true;
 250         info->setup_time = s->setup_time;
 251
 252         info->has_ram = true;
 253         info->ram = g_malloc0(sizeof(*info->ram));
 254         info->ram->transferred = ram_bytes_transferred();
 255         info->ram->remaining = 0;
 256         info->ram->total = ram_bytes_total();
 257         info->ram->duplicate = dup_mig_pages_transferred();
 258         info->ram->skipped = skipped_mig_pages_transferred();
 259         info->ram->normal = norm_mig_pages_transferred();
 260         info->ram->normal_bytes = norm_mig_bytes_transferred();
 261         info->ram->mbps = s->mbps;
 262         break;
 263     case MIG_STATE_ERROR:
 264         info->has_status = true;
 265         info->status = g_strdup("failed");
 266         break;
 267     case MIG_STATE_CANCELLED:
 268         info->has_status = true;
 269         info->status = g_strdup("cancelled");
 270         break;
 271     }
 272
 273     return info;
 274 }
 275
 276 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
 277                                   Error **errp)
 278 {
 279     MigrationState *s = migrate_get_current();
 280     MigrationCapabilityStatusList *cap;
 281
 282     if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) {
 283         error_set(errp, QERR_MIGRATION_ACTIVE);
 284         return;
 285     }
 286
 287     for (cap = params; cap; cap = cap->next) {
 288         s->enabled_capabilities[cap->value->capability] = cap->value->state;
 289     }
 290 }
 291
 292 /* shared migration helpers */
 293
 294 static void migrate_set_state(MigrationState *s, int old_state, int new_state)
 295 {
 296     if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) {
 297         trace_migrate_set_state(new_state);
 298     }
 299 }
 300
 301 static void migrate_fd_cleanup(void *opaque)
 302 {
 303     MigrationState *s = opaque;
 304
 305     qemu_bh_delete(s->cleanup_bh);
 306     s->cleanup_bh = NULL;
 307
 308     if (s->file) {
 309         DPRINTF("closing file\n");
 310         qemu_mutex_unlock_iothread();
 311         qemu_thread_join(&s->thread);
 312         qemu_mutex_lock_iothread();
 313
 314         qemu_fclose(s->file);
 315         s->file = NULL;
 316     }
 317
 318     assert(s->state != MIG_STATE_ACTIVE);
 319
 320     if (s->state != MIG_STATE_COMPLETED) {
 321         qemu_savevm_state_cancel();
 322         if (s->state == MIG_STATE_CANCELLING) {
 323             migrate_set_state(s, MIG_STATE_CANCELLING, MIG_STATE_CANCELLED);
 324         }
 325     }
 326
 327     notifier_list_notify(&migration_state_notifiers, s);
 328 }
 329
 330 void migrate_fd_error(MigrationState *s)
 331 {
 332     DPRINTF("setting error state\n");
 333     assert(s->file == NULL);
 334     s->state = MIG_STATE_ERROR;
 335     trace_migrate_set_state(MIG_STATE_ERROR);
 336     notifier_list_notify(&migration_state_notifiers, s);
 337 }
 338
 339 static void migrate_fd_cancel(MigrationState *s)
 340 {
 341     int old_state ;
 342     DPRINTF("cancelling migration\n");
 343
 344     do {
 345         old_state = s->state;
 346         if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE) {
 347             break;
 348         }
 349         migrate_set_state(s, old_state, MIG_STATE_CANCELLING);
 350     } while (s->state != MIG_STATE_CANCELLING);
 351 }
 352
 353 void add_migration_state_change_notifier(Notifier *notify)
 354 {
 355     notifier_list_add(&migration_state_notifiers, notify);
 356 }
 357
 358 void remove_migration_state_change_notifier(Notifier *notify)
 359 {
 360     notifier_remove(notify);
 361 }
 362
 363 bool migration_in_setup(MigrationState *s)
 364 {
 365     return s->state == MIG_STATE_SETUP;
 366 }
 367
 368 bool migration_has_finished(MigrationState *s)
 369 {
 370     return s->state == MIG_STATE_COMPLETED;
 371 }
 372
 373 bool migration_has_failed(MigrationState *s)
 374 {
 375     return (s->state == MIG_STATE_CANCELLED ||
 376             s->state == MIG_STATE_ERROR);
 377 }
 378
 379 static MigrationState *migrate_init(const MigrationParams *params)
 380 {
 381     MigrationState *s = migrate_get_current();
 382     int64_t bandwidth_limit = s->bandwidth_limit;
 383     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
 384     int64_t xbzrle_cache_size = s->xbzrle_cache_size;
 385
 386     memcpy(enabled_capabilities, s->enabled_capabilities,
 387            sizeof(enabled_capabilities));
 388
 389     memset(s, 0, sizeof(*s));
 390     s->params = *params;
 391     memcpy(s->enabled_capabilities, enabled_capabilities,
 392            sizeof(enabled_capabilities));
 393     s->xbzrle_cache_size = xbzrle_cache_size;
 394
 395     s->bandwidth_limit = bandwidth_limit;
 396     s->state = MIG_STATE_SETUP;
 397     trace_migrate_set_state(MIG_STATE_SETUP);
 398
 399     s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 400     return s;
 401 }
 402
 403 static GSList *migration_blockers;
 404
 405 void migrate_add_blocker(Error *reason)
 406 {
 407     migration_blockers = g_slist_prepend(migration_blockers, reason);
 408 }
 409
 410 void migrate_del_blocker(Error *reason)
 411 {
 412     migration_blockers = g_slist_remove(migration_blockers, reason);
 413 }
 414
 415 void qmp_migrate(const char *uri, bool has_blk, bool blk,
 416                  bool has_inc, bool inc, bool has_detach, bool detach,
 417                  Error **errp)
 418 {
 419     Error *local_err = NULL;
 420     MigrationState *s = migrate_get_current();
 421     MigrationParams params;
 422     const char *p;
 423
 424     params.blk = has_blk && blk;
 425     params.shared = has_inc && inc;
 426
 427     if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP ||
 428         s->state == MIG_STATE_CANCELLING) {
 429         error_set(errp, QERR_MIGRATION_ACTIVE);
 430         return;
 431     }
 432
 433     if (qemu_savevm_state_blocked(errp)) {
 434         return;
 435     }
 436
 437     if (migration_blockers) {
 438         *errp = error_copy(migration_blockers->data);
 439         return;
 440     }
 441
 442     s = migrate_init(&params);
 443
 444     if (strstart(uri, "tcp:", &p)) {
 445         tcp_start_outgoing_migration(s, p, &local_err);
 446 #ifdef CONFIG_RDMA
 447     } else if (strstart(uri, "rdma:", &p)) {
 448         rdma_start_outgoing_migration(s, p, &local_err);
 449 #endif
 450 #if !defined(WIN32)
 451     } else if (strstart(uri, "exec:", &p)) {
 452         exec_start_outgoing_migration(s, p, &local_err);
 453     } else if (strstart(uri, "unix:", &p)) {
 454         unix_start_outgoing_migration(s, p, &local_err);
 455     } else if (strstart(uri, "fd:", &p)) {
 456         fd_start_outgoing_migration(s, p, &local_err);
 457 #endif
 458     } else {
 459         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol");
 460         s->state = MIG_STATE_ERROR;
 461         return;
 462     }
 463
 464     if (local_err) {
 465         migrate_fd_error(s);
 466         error_propagate(errp, local_err);
 467         return;
 468     }
 469 }
 470
 471 void qmp_migrate_cancel(Error **errp)
 472 {
 473     migrate_fd_cancel(migrate_get_current());
 474 }
 475
 476 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
 477 {
 478     MigrationState *s = migrate_get_current();
 479     int64_t new_size;
 480
 481     /* Check for truncation */
 482     if (value != (size_t)value) {
 483         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 484                   "exceeding address space");
 485         return;
 486     }
 487
 488     /* Cache should not be larger than guest ram size */
 489     if (value > ram_bytes_total()) {
 490         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 491                   "exceeds guest ram size ");
 492         return;
 493     }
 494
 495     new_size = xbzrle_cache_resize(value);
 496     if (new_size < 0) {
 497         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 498                   "is smaller than page size");
 499         return;
 500     }
 501
 502     s->xbzrle_cache_size = new_size;
 503 }
 504
 505 int64_t qmp_query_migrate_cache_size(Error **errp)
 506 {
 507     return migrate_xbzrle_cache_size();
 508 }
 509
 510 void qmp_migrate_set_speed(int64_t value, Error **errp)
 511 {
 512     MigrationState *s;
 513
 514     if (value < 0) {
 515         value = 0;
 516     }
 517     if (value > SIZE_MAX) {
 518         value = SIZE_MAX;
 519     }
 520
 521     s = migrate_get_current();
 522     s->bandwidth_limit = value;
 523     if (s->file) {
 524         qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO);
 525     }
 526 }
 527
 528 void qmp_migrate_set_downtime(double value, Error **errp)
 529 {
 530     value *= 1e9;
 531     value = MAX(0, MIN(UINT64_MAX, value));
 532     max_downtime = (uint64_t)value;
 533 }
 534
 535 bool migrate_rdma_pin_all(void)
 536 {
 537     MigrationState *s;
 538
 539     s = migrate_get_current();
 540
 541     return s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL];
 542 }
 543
 544 bool migrate_auto_converge(void)
 545 {
 546     MigrationState *s;
 547
 548     s = migrate_get_current();
 549
 550     return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
 551 }
 552
 553 bool migrate_zero_blocks(void)
 554 {
 555     MigrationState *s;
 556
 557     s = migrate_get_current();
 558
 559     return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
 560 }
 561
 562 int migrate_use_xbzrle(void)
 563 {
 564     MigrationState *s;
 565
 566     s = migrate_get_current();
 567
 568     return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
 569 }
 570
 571 int64_t migrate_xbzrle_cache_size(void)
 572 {
 573     MigrationState *s;
 574
 575     s = migrate_get_current();
 576
 577     return s->xbzrle_cache_size;
 578 }
 579
 580 /* migration thread support */
 581
 582 static void *migration_thread(void *opaque)
 583 {
 584     MigrationState *s = opaque;
 585     int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 586     int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 587     int64_t initial_bytes = 0;
 588     int64_t max_size = 0;
 589     int64_t start_time = initial_time;
 590     bool old_vm_running = false;
 591
 592     DPRINTF("beginning savevm\n");
 593     qemu_savevm_state_begin(s->file, &s->params);
 594
 595     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
 596     migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE);
 597
 598     DPRINTF("setup complete\n");
 599
 600     while (s->state == MIG_STATE_ACTIVE) {
 601         int64_t current_time;
 602         uint64_t pending_size;
 603
 604         if (!qemu_file_rate_limit(s->file)) {
 605             DPRINTF("iterate\n");
 606             pending_size = qemu_savevm_state_pending(s->file, max_size);
 607             DPRINTF("pending size %" PRIu64 " max %" PRIu64 "\n",
 608                     pending_size, max_size);
 609             if (pending_size && pending_size >= max_size) {
 610                 qemu_savevm_state_iterate(s->file);
 611             } else {
 612                 int ret;
 613
 614                 DPRINTF("done iterating\n");
 615                 qemu_mutex_lock_iothread();
 616                 start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 617                 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
 618                 old_vm_running = runstate_is_running();
 619
 620                 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
 621                 if (ret >= 0) {
 622                     qemu_file_set_rate_limit(s->file, INT64_MAX);
 623                     qemu_savevm_state_complete(s->file);
 624                 }
 625                 qemu_mutex_unlock_iothread();
 626
 627                 if (ret < 0) {
 628                     migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
 629                     break;
 630                 }
 631
 632                 if (!qemu_file_get_error(s->file)) {
 633                     migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);
 634                     break;
 635                 }
 636             }
 637         }
 638
 639         if (qemu_file_get_error(s->file)) {
 640             migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
 641             break;
 642         }
 643         current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 644         if (current_time >= initial_time + BUFFER_DELAY) {
 645             uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;
 646             uint64_t time_spent = current_time - initial_time;
 647             double bandwidth = transferred_bytes / time_spent;
 648             max_size = bandwidth * migrate_max_downtime() / 1000000;
 649
 650             s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
 651                     ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
 652
 653             DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64
 654                     " bandwidth %g max_size %" PRId64 "\n",
 655                     transferred_bytes, time_spent, bandwidth, max_size);
 656             /* if we haven't sent anything, we don't want to recalculate
 657                10000 is a small enough number for our purposes */
 658             if (s->dirty_bytes_rate && transferred_bytes > 10000) {
 659                 s->expected_downtime = s->dirty_bytes_rate / bandwidth;
 660             }
 661
 662             qemu_file_reset_rate_limit(s->file);
 663             initial_time = current_time;
 664             initial_bytes = qemu_ftell(s->file);
 665         }
 666         if (qemu_file_rate_limit(s->file)) {
 667             /* usleep expects microseconds */
 668             g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
 669         }
 670     }
 671
 672     qemu_mutex_lock_iothread();
 673     if (s->state == MIG_STATE_COMPLETED) {
 674         int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 675         s->total_time = end_time - s->total_time;
 676         s->downtime = end_time - start_time;
 677         runstate_set(RUN_STATE_POSTMIGRATE);
 678     } else {
 679         if (old_vm_running) {
 680             vm_start();
 681         }
 682     }
 683     qemu_bh_schedule(s->cleanup_bh);
 684     qemu_mutex_unlock_iothread();
 685
 686     return NULL;
 687 }
 688
 689 void migrate_fd_connect(MigrationState *s)
 690 {
 691     s->state = MIG_STATE_SETUP;
 692     trace_migrate_set_state(MIG_STATE_SETUP);
 693
 694     /* This is a best 1st approximation. ns to ms */
 695     s->expected_downtime = max_downtime/1000000;
 696     s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
 697
 698     qemu_file_set_rate_limit(s->file,
 699                              s->bandwidth_limit / XFER_LIMIT_RATIO);
 700
 701     /* Notify before starting migration thread */
 702     notifier_list_notify(&migration_state_notifiers, s);
 703
 704     qemu_thread_create(&s->thread, "migration", migration_thread, s,
 705                        QEMU_THREAD_JOINABLE);
 706 }