migration/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/error-report.h"
  18 #include "qemu/main-loop.h"
  19 #include "migration/migration.h"
  20 #include "migration/qemu-file.h"
  21 #include "sysemu/sysemu.h"
  22 #include "block/block.h"
  23 #include "qapi/qmp/qerror.h"
  24 #include "qemu/sockets.h"
  25 #include "qemu/rcu.h"
  26 #include "migration/block.h"
  27 #include "qemu/thread.h"
  28 #include "qmp-commands.h"
  29 #include "trace.h"
  30 #include "qapi/util.h"
  31 #include "qapi-event.h"
  32 #include "qom/cpu.h"
  33
  34 #define MAX_THROTTLE  (32 << 20)      /* Migration transfer speed throttling */
  35
  36 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
  37  * data. */
  38 #define BUFFER_DELAY     100
  39 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
  40
  41 /* Default compression thread count */
  42 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
  43 /* Default decompression thread count, usually decompression is at
  44  * least 4 times as fast as compression.*/
  45 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
  46 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
  47 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
  48 /* Define default autoconverge cpu throttle migration parameters */
  49 #define DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL 20
  50 #define DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT 10
  51
  52 /* Migration XBZRLE default cache size */
  53 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
  54
  55 static NotifierList migration_state_notifiers =
  56     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
  57
  58 static bool deferred_incoming;
  59
  60 /* When we add fault tolerance, we could have several
  61    migrations at once.  For now we don't need to add
  62    dynamic creation of migration */
  63
  64 /* For outgoing */
  65 MigrationState *migrate_get_current(void)
  66 {
  67     static MigrationState current_migration = {
  68         .state = MIGRATION_STATUS_NONE,
  69         .bandwidth_limit = MAX_THROTTLE,
  70         .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
  71         .mbps = -1,
  72         .parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] =
  73                 DEFAULT_MIGRATE_COMPRESS_LEVEL,
  74         .parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
  75                 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT,
  76         .parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
  77                 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
  78         .parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL] =
  79                 DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL,
  80         .parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] =
  81                 DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT,
  82     };
  83
  84     return &current_migration;
  85 }
  86
  87 /* For incoming */
  88 static MigrationIncomingState *mis_current;
  89
  90 MigrationIncomingState *migration_incoming_get_current(void)
  91 {
  92     return mis_current;
  93 }
  94
  95 MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
  96 {
  97     mis_current = g_new0(MigrationIncomingState, 1);
  98     mis_current->from_src_file = f;
  99     QLIST_INIT(&mis_current->loadvm_handlers);
 100     qemu_mutex_init(&mis_current->rp_mutex);
 101     qemu_event_init(&mis_current->main_thread_load_event, false);
 102
 103     return mis_current;
 104 }
 105
 106 void migration_incoming_state_destroy(void)
 107 {
 108     qemu_event_destroy(&mis_current->main_thread_load_event);
 109     loadvm_free_handlers(mis_current);
 110     g_free(mis_current);
 111     mis_current = NULL;
 112 }
 113
 114
 115 typedef struct {
 116     bool optional;
 117     uint32_t size;
 118     uint8_t runstate[100];
 119     RunState state;
 120     bool received;
 121 } GlobalState;
 122
 123 static GlobalState global_state;
 124
 125 int global_state_store(void)
 126 {
 127     if (!runstate_store((char *)global_state.runstate,
 128                         sizeof(global_state.runstate))) {
 129         error_report("runstate name too big: %s", global_state.runstate);
 130         trace_migrate_state_too_big();
 131         return -EINVAL;
 132     }
 133     return 0;
 134 }
 135
 136 void global_state_store_running(void)
 137 {
 138     const char *state = RunState_lookup[RUN_STATE_RUNNING];
 139     strncpy((char *)global_state.runstate,
 140            state, sizeof(global_state.runstate));
 141 }
 142
 143 static bool global_state_received(void)
 144 {
 145     return global_state.received;
 146 }
 147
 148 static RunState global_state_get_runstate(void)
 149 {
 150     return global_state.state;
 151 }
 152
 153 void global_state_set_optional(void)
 154 {
 155     global_state.optional = true;
 156 }
 157
 158 static bool global_state_needed(void *opaque)
 159 {
 160     GlobalState *s = opaque;
 161     char *runstate = (char *)s->runstate;
 162
 163     /* If it is not optional, it is mandatory */
 164
 165     if (s->optional == false) {
 166         return true;
 167     }
 168
 169     /* If state is running or paused, it is not needed */
 170
 171     if (strcmp(runstate, "running") == 0 ||
 172         strcmp(runstate, "paused") == 0) {
 173         return false;
 174     }
 175
 176     /* for any other state it is needed */
 177     return true;
 178 }
 179
 180 static int global_state_post_load(void *opaque, int version_id)
 181 {
 182     GlobalState *s = opaque;
 183     Error *local_err = NULL;
 184     int r;
 185     char *runstate = (char *)s->runstate;
 186
 187     s->received = true;
 188     trace_migrate_global_state_post_load(runstate);
 189
 190     r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE_MAX,
 191                                 -1, &local_err);
 192
 193     if (r == -1) {
 194         if (local_err) {
 195             error_report_err(local_err);
 196         }
 197         return -EINVAL;
 198     }
 199     s->state = r;
 200
 201     return 0;
 202 }
 203
 204 static void global_state_pre_save(void *opaque)
 205 {
 206     GlobalState *s = opaque;
 207
 208     trace_migrate_global_state_pre_save((char *)s->runstate);
 209     s->size = strlen((char *)s->runstate) + 1;
 210 }
 211
 212 static const VMStateDescription vmstate_globalstate = {
 213     .name = "globalstate",
 214     .version_id = 1,
 215     .minimum_version_id = 1,
 216     .post_load = global_state_post_load,
 217     .pre_save = global_state_pre_save,
 218     .needed = global_state_needed,
 219     .fields = (VMStateField[]) {
 220         VMSTATE_UINT32(size, GlobalState),
 221         VMSTATE_BUFFER(runstate, GlobalState),
 222         VMSTATE_END_OF_LIST()
 223     },
 224 };
 225
 226 void register_global_state(void)
 227 {
 228     /* We would use it independently that we receive it */
 229     strcpy((char *)&global_state.runstate, "");
 230     global_state.received = false;
 231     vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
 232 }
 233
 234 static void migrate_generate_event(int new_state)
 235 {
 236     if (migrate_use_events()) {
 237         qapi_event_send_migration(new_state, &error_abort);
 238     }
 239 }
 240
 241 /*
 242  * Called on -incoming with a defer: uri.
 243  * The migration can be started later after any parameters have been
 244  * changed.
 245  */
 246 static void deferred_incoming_migration(Error **errp)
 247 {
 248     if (deferred_incoming) {
 249         error_setg(errp, "Incoming migration already deferred");
 250     }
 251     deferred_incoming = true;
 252 }
 253
 254 void qemu_start_incoming_migration(const char *uri, Error **errp)
 255 {
 256     const char *p;
 257
 258     qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort);
 259     if (!strcmp(uri, "defer")) {
 260         deferred_incoming_migration(errp);
 261     } else if (strstart(uri, "tcp:", &p)) {
 262         tcp_start_incoming_migration(p, errp);
 263 #ifdef CONFIG_RDMA
 264     } else if (strstart(uri, "rdma:", &p)) {
 265         rdma_start_incoming_migration(p, errp);
 266 #endif
 267 #if !defined(WIN32)
 268     } else if (strstart(uri, "exec:", &p)) {
 269         exec_start_incoming_migration(p, errp);
 270     } else if (strstart(uri, "unix:", &p)) {
 271         unix_start_incoming_migration(p, errp);
 272     } else if (strstart(uri, "fd:", &p)) {
 273         fd_start_incoming_migration(p, errp);
 274 #endif
 275     } else {
 276         error_setg(errp, "unknown migration protocol: %s", uri);
 277     }
 278 }
 279
 280 static void process_incoming_migration_co(void *opaque)
 281 {
 282     QEMUFile *f = opaque;
 283     Error *local_err = NULL;
 284     int ret;
 285
 286     migration_incoming_state_new(f);
 287     migrate_generate_event(MIGRATION_STATUS_ACTIVE);
 288     ret = qemu_loadvm_state(f);
 289
 290     qemu_fclose(f);
 291     free_xbzrle_decoded_buf();
 292     migration_incoming_state_destroy();
 293
 294     if (ret < 0) {
 295         migrate_generate_event(MIGRATION_STATUS_FAILED);
 296         error_report("load of migration failed: %s", strerror(-ret));
 297         migrate_decompress_threads_join();
 298         exit(EXIT_FAILURE);
 299     }
 300
 301     /* Make sure all file formats flush their mutable metadata */
 302     bdrv_invalidate_cache_all(&local_err);
 303     if (local_err) {
 304         migrate_generate_event(MIGRATION_STATUS_FAILED);
 305         error_report_err(local_err);
 306         migrate_decompress_threads_join();
 307         exit(EXIT_FAILURE);
 308     }
 309
 310     /*
 311      * This must happen after all error conditions are dealt with and
 312      * we're sure the VM is going to be running on this host.
 313      */
 314     qemu_announce_self();
 315
 316     /* If global state section was not received or we are in running
 317        state, we need to obey autostart. Any other state is set with
 318        runstate_set. */
 319
 320     if (!global_state_received() ||
 321         global_state_get_runstate() == RUN_STATE_RUNNING) {
 322         if (autostart) {
 323             vm_start();
 324         } else {
 325             runstate_set(RUN_STATE_PAUSED);
 326         }
 327     } else {
 328         runstate_set(global_state_get_runstate());
 329     }
 330     migrate_decompress_threads_join();
 331     /*
 332      * This must happen after any state changes since as soon as an external
 333      * observer sees this event they might start to prod at the VM assuming
 334      * it's ready to use.
 335      */
 336     migrate_generate_event(MIGRATION_STATUS_COMPLETED);
 337 }
 338
 339 void process_incoming_migration(QEMUFile *f)
 340 {
 341     Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
 342     int fd = qemu_get_fd(f);
 343
 344     assert(fd != -1);
 345     migrate_decompress_threads_create();
 346     qemu_set_nonblock(fd);
 347     qemu_coroutine_enter(co, f);
 348 }
 349
 350 /*
 351  * Send a message on the return channel back to the source
 352  * of the migration.
 353  */
 354 void migrate_send_rp_message(MigrationIncomingState *mis,
 355                              enum mig_rp_message_type message_type,
 356                              uint16_t len, void *data)
 357 {
 358     trace_migrate_send_rp_message((int)message_type, len);
 359     qemu_mutex_lock(&mis->rp_mutex);
 360     qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
 361     qemu_put_be16(mis->to_src_file, len);
 362     qemu_put_buffer(mis->to_src_file, data, len);
 363     qemu_fflush(mis->to_src_file);
 364     qemu_mutex_unlock(&mis->rp_mutex);
 365 }
 366
 367 /*
 368  * Send a 'SHUT' message on the return channel with the given value
 369  * to indicate that we've finished with the RP.  Non-0 value indicates
 370  * error.
 371  */
 372 void migrate_send_rp_shut(MigrationIncomingState *mis,
 373                           uint32_t value)
 374 {
 375     uint32_t buf;
 376
 377     buf = cpu_to_be32(value);
 378     migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
 379 }
 380
 381 /*
 382  * Send a 'PONG' message on the return channel with the given value
 383  * (normally in response to a 'PING')
 384  */
 385 void migrate_send_rp_pong(MigrationIncomingState *mis,
 386                           uint32_t value)
 387 {
 388     uint32_t buf;
 389
 390     buf = cpu_to_be32(value);
 391     migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
 392 }
 393
 394 /* amount of nanoseconds we are willing to wait for migration to be down.
 395  * the choice of nanoseconds is because it is the maximum resolution that
 396  * get_clock() can achieve. It is an internal measure. All user-visible
 397  * units must be in seconds */
 398 static uint64_t max_downtime = 300000000;
 399
 400 uint64_t migrate_max_downtime(void)
 401 {
 402     return max_downtime;
 403 }
 404
 405 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
 406 {
 407     MigrationCapabilityStatusList *head = NULL;
 408     MigrationCapabilityStatusList *caps;
 409     MigrationState *s = migrate_get_current();
 410     int i;
 411
 412     caps = NULL; /* silence compiler warning */
 413     for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
 414         if (head == NULL) {
 415             head = g_malloc0(sizeof(*caps));
 416             caps = head;
 417         } else {
 418             caps->next = g_malloc0(sizeof(*caps));
 419             caps = caps->next;
 420         }
 421         caps->value =
 422             g_malloc(sizeof(*caps->value));
 423         caps->value->capability = i;
 424         caps->value->state = s->enabled_capabilities[i];
 425     }
 426
 427     return head;
 428 }
 429
 430 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
 431 {
 432     MigrationParameters *params;
 433     MigrationState *s = migrate_get_current();
 434
 435     params = g_malloc0(sizeof(*params));
 436     params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
 437     params->compress_threads =
 438             s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
 439     params->decompress_threads =
 440             s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
 441     params->x_cpu_throttle_initial =
 442             s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL];
 443     params->x_cpu_throttle_increment =
 444             s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT];
 445
 446     return params;
 447 }
 448
 449 /*
 450  * Return true if we're already in the middle of a migration
 451  * (i.e. any of the active or setup states)
 452  */
 453 static bool migration_is_setup_or_active(int state)
 454 {
 455     switch (state) {
 456     case MIGRATION_STATUS_ACTIVE:
 457     case MIGRATION_STATUS_SETUP:
 458         return true;
 459
 460     default:
 461         return false;
 462
 463     }
 464 }
 465
 466 static void get_xbzrle_cache_stats(MigrationInfo *info)
 467 {
 468     if (migrate_use_xbzrle()) {
 469         info->has_xbzrle_cache = true;
 470         info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
 471         info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
 472         info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
 473         info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
 474         info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
 475         info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate();
 476         info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
 477     }
 478 }
 479
 480 MigrationInfo *qmp_query_migrate(Error **errp)
 481 {
 482     MigrationInfo *info = g_malloc0(sizeof(*info));
 483     MigrationState *s = migrate_get_current();
 484
 485     switch (s->state) {
 486     case MIGRATION_STATUS_NONE:
 487         /* no migration has happened ever */
 488         break;
 489     case MIGRATION_STATUS_SETUP:
 490         info->has_status = true;
 491         info->has_total_time = false;
 492         break;
 493     case MIGRATION_STATUS_ACTIVE:
 494     case MIGRATION_STATUS_CANCELLING:
 495         info->has_status = true;
 496         info->has_total_time = true;
 497         info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
 498             - s->total_time;
 499         info->has_expected_downtime = true;
 500         info->expected_downtime = s->expected_downtime;
 501         info->has_setup_time = true;
 502         info->setup_time = s->setup_time;
 503
 504         info->has_ram = true;
 505         info->ram = g_malloc0(sizeof(*info->ram));
 506         info->ram->transferred = ram_bytes_transferred();
 507         info->ram->remaining = ram_bytes_remaining();
 508         info->ram->total = ram_bytes_total();
 509         info->ram->duplicate = dup_mig_pages_transferred();
 510         info->ram->skipped = skipped_mig_pages_transferred();
 511         info->ram->normal = norm_mig_pages_transferred();
 512         info->ram->normal_bytes = norm_mig_bytes_transferred();
 513         info->ram->dirty_pages_rate = s->dirty_pages_rate;
 514         info->ram->mbps = s->mbps;
 515         info->ram->dirty_sync_count = s->dirty_sync_count;
 516
 517         if (blk_mig_active()) {
 518             info->has_disk = true;
 519             info->disk = g_malloc0(sizeof(*info->disk));
 520             info->disk->transferred = blk_mig_bytes_transferred();
 521             info->disk->remaining = blk_mig_bytes_remaining();
 522             info->disk->total = blk_mig_bytes_total();
 523         }
 524
 525         if (cpu_throttle_active()) {
 526             info->has_x_cpu_throttle_percentage = true;
 527             info->x_cpu_throttle_percentage = cpu_throttle_get_percentage();
 528         }
 529
 530         get_xbzrle_cache_stats(info);
 531         break;
 532     case MIGRATION_STATUS_COMPLETED:
 533         get_xbzrle_cache_stats(info);
 534
 535         info->has_status = true;
 536         info->has_total_time = true;
 537         info->total_time = s->total_time;
 538         info->has_downtime = true;
 539         info->downtime = s->downtime;
 540         info->has_setup_time = true;
 541         info->setup_time = s->setup_time;
 542
 543         info->has_ram = true;
 544         info->ram = g_malloc0(sizeof(*info->ram));
 545         info->ram->transferred = ram_bytes_transferred();
 546         info->ram->remaining = 0;
 547         info->ram->total = ram_bytes_total();
 548         info->ram->duplicate = dup_mig_pages_transferred();
 549         info->ram->skipped = skipped_mig_pages_transferred();
 550         info->ram->normal = norm_mig_pages_transferred();
 551         info->ram->normal_bytes = norm_mig_bytes_transferred();
 552         info->ram->mbps = s->mbps;
 553         info->ram->dirty_sync_count = s->dirty_sync_count;
 554         break;
 555     case MIGRATION_STATUS_FAILED:
 556         info->has_status = true;
 557         break;
 558     case MIGRATION_STATUS_CANCELLED:
 559         info->has_status = true;
 560         break;
 561     }
 562     info->status = s->state;
 563
 564     return info;
 565 }
 566
 567 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
 568                                   Error **errp)
 569 {
 570     MigrationState *s = migrate_get_current();
 571     MigrationCapabilityStatusList *cap;
 572
 573     if (migration_is_setup_or_active(s->state)) {
 574         error_setg(errp, QERR_MIGRATION_ACTIVE);
 575         return;
 576     }
 577
 578     for (cap = params; cap; cap = cap->next) {
 579         s->enabled_capabilities[cap->value->capability] = cap->value->state;
 580     }
 581
 582     if (migrate_postcopy_ram()) {
 583         if (migrate_use_compression()) {
 584             /* The decompression threads asynchronously write into RAM
 585              * rather than use the atomic copies needed to avoid
 586              * userfaulting.  It should be possible to fix the decompression
 587              * threads for compatibility in future.
 588              */
 589             error_report("Postcopy is not currently compatible with "
 590                          "compression");
 591             s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM] =
 592                 false;
 593         }
 594     }
 595 }
 596
 597 void qmp_migrate_set_parameters(bool has_compress_level,
 598                                 int64_t compress_level,
 599                                 bool has_compress_threads,
 600                                 int64_t compress_threads,
 601                                 bool has_decompress_threads,
 602                                 int64_t decompress_threads,
 603                                 bool has_x_cpu_throttle_initial,
 604                                 int64_t x_cpu_throttle_initial,
 605                                 bool has_x_cpu_throttle_increment,
 606                                 int64_t x_cpu_throttle_increment, Error **errp)
 607 {
 608     MigrationState *s = migrate_get_current();
 609
 610     if (has_compress_level && (compress_level < 0 || compress_level > 9)) {
 611         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
 612                    "is invalid, it should be in the range of 0 to 9");
 613         return;
 614     }
 615     if (has_compress_threads &&
 616             (compress_threads < 1 || compress_threads > 255)) {
 617         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 618                    "compress_threads",
 619                    "is invalid, it should be in the range of 1 to 255");
 620         return;
 621     }
 622     if (has_decompress_threads &&
 623             (decompress_threads < 1 || decompress_threads > 255)) {
 624         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 625                    "decompress_threads",
 626                    "is invalid, it should be in the range of 1 to 255");
 627         return;
 628     }
 629     if (has_x_cpu_throttle_initial &&
 630             (x_cpu_throttle_initial < 1 || x_cpu_throttle_initial > 99)) {
 631         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 632                    "x_cpu_throttle_initial",
 633                    "an integer in the range of 1 to 99");
 634     }
 635     if (has_x_cpu_throttle_increment &&
 636             (x_cpu_throttle_increment < 1 || x_cpu_throttle_increment > 99)) {
 637         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 638                    "x_cpu_throttle_increment",
 639                    "an integer in the range of 1 to 99");
 640     }
 641
 642     if (has_compress_level) {
 643         s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
 644     }
 645     if (has_compress_threads) {
 646         s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads;
 647     }
 648     if (has_decompress_threads) {
 649         s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
 650                                                     decompress_threads;
 651     }
 652     if (has_x_cpu_throttle_initial) {
 653         s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL] =
 654                                                     x_cpu_throttle_initial;
 655     }
 656
 657     if (has_x_cpu_throttle_increment) {
 658         s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] =
 659                                                     x_cpu_throttle_increment;
 660     }
 661 }
 662
 663 /* shared migration helpers */
 664
 665 static void migrate_set_state(MigrationState *s, int old_state, int new_state)
 666 {
 667     if (atomic_cmpxchg(&s->state, old_state, new_state) == old_state) {
 668         trace_migrate_set_state(new_state);
 669         migrate_generate_event(new_state);
 670     }
 671 }
 672
 673 static void migrate_fd_cleanup(void *opaque)
 674 {
 675     MigrationState *s = opaque;
 676
 677     qemu_bh_delete(s->cleanup_bh);
 678     s->cleanup_bh = NULL;
 679
 680     if (s->file) {
 681         trace_migrate_fd_cleanup();
 682         qemu_mutex_unlock_iothread();
 683         qemu_thread_join(&s->thread);
 684         qemu_mutex_lock_iothread();
 685
 686         migrate_compress_threads_join();
 687         qemu_fclose(s->file);
 688         s->file = NULL;
 689     }
 690
 691     assert(s->state != MIGRATION_STATUS_ACTIVE);
 692
 693     if (s->state == MIGRATION_STATUS_CANCELLING) {
 694         migrate_set_state(s, MIGRATION_STATUS_CANCELLING,
 695                           MIGRATION_STATUS_CANCELLED);
 696     }
 697
 698     notifier_list_notify(&migration_state_notifiers, s);
 699 }
 700
 701 void migrate_fd_error(MigrationState *s)
 702 {
 703     trace_migrate_fd_error();
 704     assert(s->file == NULL);
 705     migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
 706     notifier_list_notify(&migration_state_notifiers, s);
 707 }
 708
 709 static void migrate_fd_cancel(MigrationState *s)
 710 {
 711     int old_state ;
 712     QEMUFile *f = migrate_get_current()->file;
 713     trace_migrate_fd_cancel();
 714
 715     if (s->rp_state.from_dst_file) {
 716         /* shutdown the rp socket, so causing the rp thread to shutdown */
 717         qemu_file_shutdown(s->rp_state.from_dst_file);
 718     }
 719
 720     do {
 721         old_state = s->state;
 722         if (!migration_is_setup_or_active(old_state)) {
 723             break;
 724         }
 725         migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING);
 726     } while (s->state != MIGRATION_STATUS_CANCELLING);
 727
 728     /*
 729      * If we're unlucky the migration code might be stuck somewhere in a
 730      * send/write while the network has failed and is waiting to timeout;
 731      * if we've got shutdown(2) available then we can force it to quit.
 732      * The outgoing qemu file gets closed in migrate_fd_cleanup that is
 733      * called in a bh, so there is no race against this cancel.
 734      */
 735     if (s->state == MIGRATION_STATUS_CANCELLING && f) {
 736         qemu_file_shutdown(f);
 737     }
 738 }
 739
 740 void add_migration_state_change_notifier(Notifier *notify)
 741 {
 742     notifier_list_add(&migration_state_notifiers, notify);
 743 }
 744
 745 void remove_migration_state_change_notifier(Notifier *notify)
 746 {
 747     notifier_remove(notify);
 748 }
 749
 750 bool migration_in_setup(MigrationState *s)
 751 {
 752     return s->state == MIGRATION_STATUS_SETUP;
 753 }
 754
 755 bool migration_has_finished(MigrationState *s)
 756 {
 757     return s->state == MIGRATION_STATUS_COMPLETED;
 758 }
 759
 760 bool migration_has_failed(MigrationState *s)
 761 {
 762     return (s->state == MIGRATION_STATUS_CANCELLED ||
 763             s->state == MIGRATION_STATUS_FAILED);
 764 }
 765
 766 MigrationState *migrate_init(const MigrationParams *params)
 767 {
 768     MigrationState *s = migrate_get_current();
 769     int64_t bandwidth_limit = s->bandwidth_limit;
 770     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
 771     int64_t xbzrle_cache_size = s->xbzrle_cache_size;
 772     int compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
 773     int compress_thread_count =
 774             s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
 775     int decompress_thread_count =
 776             s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
 777     int x_cpu_throttle_initial =
 778             s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL];
 779     int x_cpu_throttle_increment =
 780             s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT];
 781
 782     memcpy(enabled_capabilities, s->enabled_capabilities,
 783            sizeof(enabled_capabilities));
 784
 785     memset(s, 0, sizeof(*s));
 786     s->params = *params;
 787     memcpy(s->enabled_capabilities, enabled_capabilities,
 788            sizeof(enabled_capabilities));
 789     s->xbzrle_cache_size = xbzrle_cache_size;
 790
 791     s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
 792     s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
 793                compress_thread_count;
 794     s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
 795                decompress_thread_count;
 796     s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL] =
 797                 x_cpu_throttle_initial;
 798     s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] =
 799                 x_cpu_throttle_increment;
 800     s->bandwidth_limit = bandwidth_limit;
 801     migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
 802
 803     s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 804     return s;
 805 }
 806
 807 static GSList *migration_blockers;
 808
 809 void migrate_add_blocker(Error *reason)
 810 {
 811     migration_blockers = g_slist_prepend(migration_blockers, reason);
 812 }
 813
 814 void migrate_del_blocker(Error *reason)
 815 {
 816     migration_blockers = g_slist_remove(migration_blockers, reason);
 817 }
 818
 819 void qmp_migrate_incoming(const char *uri, Error **errp)
 820 {
 821     Error *local_err = NULL;
 822     static bool once = true;
 823
 824     if (!deferred_incoming) {
 825         error_setg(errp, "For use with '-incoming defer'");
 826         return;
 827     }
 828     if (!once) {
 829         error_setg(errp, "The incoming migration has already been started");
 830     }
 831
 832     qemu_start_incoming_migration(uri, &local_err);
 833
 834     if (local_err) {
 835         error_propagate(errp, local_err);
 836         return;
 837     }
 838
 839     once = false;
 840 }
 841
 842 void qmp_migrate(const char *uri, bool has_blk, bool blk,
 843                  bool has_inc, bool inc, bool has_detach, bool detach,
 844                  Error **errp)
 845 {
 846     Error *local_err = NULL;
 847     MigrationState *s = migrate_get_current();
 848     MigrationParams params;
 849     const char *p;
 850
 851     params.blk = has_blk && blk;
 852     params.shared = has_inc && inc;
 853
 854     if (migration_is_setup_or_active(s->state) ||
 855         s->state == MIGRATION_STATUS_CANCELLING) {
 856         error_setg(errp, QERR_MIGRATION_ACTIVE);
 857         return;
 858     }
 859     if (runstate_check(RUN_STATE_INMIGRATE)) {
 860         error_setg(errp, "Guest is waiting for an incoming migration");
 861         return;
 862     }
 863
 864     if (qemu_savevm_state_blocked(errp)) {
 865         return;
 866     }
 867
 868     if (migration_blockers) {
 869         *errp = error_copy(migration_blockers->data);
 870         return;
 871     }
 872
 873     /* We are starting a new migration, so we want to start in a clean
 874        state.  This change is only needed if previous migration
 875        failed/was cancelled.  We don't use migrate_set_state() because
 876        we are setting the initial state, not changing it. */
 877     s->state = MIGRATION_STATUS_NONE;
 878
 879     s = migrate_init(&params);
 880
 881     if (strstart(uri, "tcp:", &p)) {
 882         tcp_start_outgoing_migration(s, p, &local_err);
 883 #ifdef CONFIG_RDMA
 884     } else if (strstart(uri, "rdma:", &p)) {
 885         rdma_start_outgoing_migration(s, p, &local_err);
 886 #endif
 887 #if !defined(WIN32)
 888     } else if (strstart(uri, "exec:", &p)) {
 889         exec_start_outgoing_migration(s, p, &local_err);
 890     } else if (strstart(uri, "unix:", &p)) {
 891         unix_start_outgoing_migration(s, p, &local_err);
 892     } else if (strstart(uri, "fd:", &p)) {
 893         fd_start_outgoing_migration(s, p, &local_err);
 894 #endif
 895     } else {
 896         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
 897                    "a valid migration protocol");
 898         migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
 899         return;
 900     }
 901
 902     if (local_err) {
 903         migrate_fd_error(s);
 904         error_propagate(errp, local_err);
 905         return;
 906     }
 907 }
 908
 909 void qmp_migrate_cancel(Error **errp)
 910 {
 911     migrate_fd_cancel(migrate_get_current());
 912 }
 913
 914 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
 915 {
 916     MigrationState *s = migrate_get_current();
 917     int64_t new_size;
 918
 919     /* Check for truncation */
 920     if (value != (size_t)value) {
 921         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 922                    "exceeding address space");
 923         return;
 924     }
 925
 926     /* Cache should not be larger than guest ram size */
 927     if (value > ram_bytes_total()) {
 928         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 929                    "exceeds guest ram size ");
 930         return;
 931     }
 932
 933     new_size = xbzrle_cache_resize(value);
 934     if (new_size < 0) {
 935         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
 936                    "is smaller than page size");
 937         return;
 938     }
 939
 940     s->xbzrle_cache_size = new_size;
 941 }
 942
 943 int64_t qmp_query_migrate_cache_size(Error **errp)
 944 {
 945     return migrate_xbzrle_cache_size();
 946 }
 947
 948 void qmp_migrate_set_speed(int64_t value, Error **errp)
 949 {
 950     MigrationState *s;
 951
 952     if (value < 0) {
 953         value = 0;
 954     }
 955     if (value > SIZE_MAX) {
 956         value = SIZE_MAX;
 957     }
 958
 959     s = migrate_get_current();
 960     s->bandwidth_limit = value;
 961     if (s->file) {
 962         qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO);
 963     }
 964 }
 965
 966 void qmp_migrate_set_downtime(double value, Error **errp)
 967 {
 968     value *= 1e9;
 969     value = MAX(0, MIN(UINT64_MAX, value));
 970     max_downtime = (uint64_t)value;
 971 }
 972
 973 bool migrate_postcopy_ram(void)
 974 {
 975     MigrationState *s;
 976
 977     s = migrate_get_current();
 978
 979     return s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM];
 980 }
 981
 982 bool migrate_auto_converge(void)
 983 {
 984     MigrationState *s;
 985
 986     s = migrate_get_current();
 987
 988     return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
 989 }
 990
 991 bool migrate_zero_blocks(void)
 992 {
 993     MigrationState *s;
 994
 995     s = migrate_get_current();
 996
 997     return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
 998 }
 999
1000 bool migrate_use_compression(void)
1001 {
1002     MigrationState *s;
1003
1004     s = migrate_get_current();
1005
1006     return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
1007 }
1008
1009 int migrate_compress_level(void)
1010 {
1011     MigrationState *s;
1012
1013     s = migrate_get_current();
1014
1015     return s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
1016 }
1017
1018 int migrate_compress_threads(void)
1019 {
1020     MigrationState *s;
1021
1022     s = migrate_get_current();
1023
1024     return s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
1025 }
1026
1027 int migrate_decompress_threads(void)
1028 {
1029     MigrationState *s;
1030
1031     s = migrate_get_current();
1032
1033     return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
1034 }
1035
1036 bool migrate_use_events(void)
1037 {
1038     MigrationState *s;
1039
1040     s = migrate_get_current();
1041
1042     return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
1043 }
1044
1045 int migrate_use_xbzrle(void)
1046 {
1047     MigrationState *s;
1048
1049     s = migrate_get_current();
1050
1051     return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
1052 }
1053
1054 int64_t migrate_xbzrle_cache_size(void)
1055 {
1056     MigrationState *s;
1057
1058     s = migrate_get_current();
1059
1060     return s->xbzrle_cache_size;
1061 }
1062
1063 /* migration thread support */
1064 /*
1065  * Something bad happened to the RP stream, mark an error
1066  * The caller shall print or trace something to indicate why
1067  */
1068 static void mark_source_rp_bad(MigrationState *s)
1069 {
1070     s->rp_state.error = true;
1071 }
1072
1073 static struct rp_cmd_args {
1074     ssize_t     len; /* -1 = variable */
1075     const char *name;
1076 } rp_cmd_args[] = {
1077     [MIG_RP_MSG_INVALID]        = { .len = -1, .name = "INVALID" },
1078     [MIG_RP_MSG_SHUT]           = { .len =  4, .name = "SHUT" },
1079     [MIG_RP_MSG_PONG]           = { .len =  4, .name = "PONG" },
1080     [MIG_RP_MSG_MAX]            = { .len = -1, .name = "MAX" },
1081 };
1082
1083 /*
1084  * Handles messages sent on the return path towards the source VM
1085  *
1086  */
1087 static void *source_return_path_thread(void *opaque)
1088 {
1089     MigrationState *ms = opaque;
1090     QEMUFile *rp = ms->rp_state.from_dst_file;
1091     uint16_t header_len, header_type;
1092     const int max_len = 512;
1093     uint8_t buf[max_len];
1094     uint32_t tmp32, sibling_error;
1095     int res;
1096
1097     trace_source_return_path_thread_entry();
1098     while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
1099            migration_is_setup_or_active(ms->state)) {
1100         trace_source_return_path_thread_loop_top();
1101         header_type = qemu_get_be16(rp);
1102         header_len = qemu_get_be16(rp);
1103
1104         if (header_type >= MIG_RP_MSG_MAX ||
1105             header_type == MIG_RP_MSG_INVALID) {
1106             error_report("RP: Received invalid message 0x%04x length 0x%04x",
1107                     header_type, header_len);
1108             mark_source_rp_bad(ms);
1109             goto out;
1110         }
1111
1112         if ((rp_cmd_args[header_type].len != -1 &&
1113             header_len != rp_cmd_args[header_type].len) ||
1114             header_len > max_len) {
1115             error_report("RP: Received '%s' message (0x%04x) with"
1116                     "incorrect length %d expecting %zu",
1117                     rp_cmd_args[header_type].name, header_type, header_len,
1118                     (size_t)rp_cmd_args[header_type].len);
1119             mark_source_rp_bad(ms);
1120             goto out;
1121         }
1122
1123         /* We know we've got a valid header by this point */
1124         res = qemu_get_buffer(rp, buf, header_len);
1125         if (res != header_len) {
1126             error_report("RP: Failed reading data for message 0x%04x"
1127                          " read %d expected %d",
1128                          header_type, res, header_len);
1129             mark_source_rp_bad(ms);
1130             goto out;
1131         }
1132
1133         /* OK, we have the message and the data */
1134         switch (header_type) {
1135         case MIG_RP_MSG_SHUT:
1136             sibling_error = be32_to_cpup((uint32_t *)buf);
1137             trace_source_return_path_thread_shut(sibling_error);
1138             if (sibling_error) {
1139                 error_report("RP: Sibling indicated error %d", sibling_error);
1140                 mark_source_rp_bad(ms);
1141             }
1142             /*
1143              * We'll let the main thread deal with closing the RP
1144              * we could do a shutdown(2) on it, but we're the only user
1145              * anyway, so there's nothing gained.
1146              */
1147             goto out;
1148
1149         case MIG_RP_MSG_PONG:
1150             tmp32 = be32_to_cpup((uint32_t *)buf);
1151             trace_source_return_path_thread_pong(tmp32);
1152             break;
1153
1154         default:
1155             break;
1156         }
1157     }
1158     if (rp && qemu_file_get_error(rp)) {
1159         trace_source_return_path_thread_bad_end();
1160         mark_source_rp_bad(ms);
1161     }
1162
1163     trace_source_return_path_thread_end();
1164 out:
1165     ms->rp_state.from_dst_file = NULL;
1166     qemu_fclose(rp);
1167     return NULL;
1168 }
1169
1170 __attribute__ (( unused )) /* Until later in patch series */
1171 static int open_return_path_on_source(MigrationState *ms)
1172 {
1173
1174     ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->file);
1175     if (!ms->rp_state.from_dst_file) {
1176         return -1;
1177     }
1178
1179     trace_open_return_path_on_source();
1180     qemu_thread_create(&ms->rp_state.rp_thread, "return path",
1181                        source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
1182
1183     trace_open_return_path_on_source_continue();
1184
1185     return 0;
1186 }
1187
1188 __attribute__ (( unused )) /* Until later in patch series */
1189 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1190 static int await_return_path_close_on_source(MigrationState *ms)
1191 {
1192     /*
1193      * If this is a normal exit then the destination will send a SHUT and the
1194      * rp_thread will exit, however if there's an error we need to cause
1195      * it to exit.
1196      */
1197     if (qemu_file_get_error(ms->file) && ms->rp_state.from_dst_file) {
1198         /*
1199          * shutdown(2), if we have it, will cause it to unblock if it's stuck
1200          * waiting for the destination.
1201          */
1202         qemu_file_shutdown(ms->rp_state.from_dst_file);
1203         mark_source_rp_bad(ms);
1204     }
1205     trace_await_return_path_close_on_source_joining();
1206     qemu_thread_join(&ms->rp_state.rp_thread);
1207     trace_await_return_path_close_on_source_close();
1208     return ms->rp_state.error;
1209 }
1210
1211 /**
1212  * migration_completion: Used by migration_thread when there's not much left.
1213  *   The caller 'breaks' the loop when this returns.
1214  *
1215  * @s: Current migration state
1216  * @*old_vm_running: Pointer to old_vm_running flag
1217  * @*start_time: Pointer to time to update
1218  */
1219 static void migration_completion(MigrationState *s, bool *old_vm_running,
1220                                  int64_t *start_time)
1221 {
1222     int ret;
1223
1224     qemu_mutex_lock_iothread();
1225     *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1226     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
1227     *old_vm_running = runstate_is_running();
1228
1229     ret = global_state_store();
1230     if (!ret) {
1231         ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
1232         if (ret >= 0) {
1233             qemu_file_set_rate_limit(s->file, INT64_MAX);
1234             qemu_savevm_state_complete_precopy(s->file);
1235         }
1236     }
1237     qemu_mutex_unlock_iothread();
1238
1239     if (ret < 0) {
1240         goto fail;
1241     }
1242
1243     if (qemu_file_get_error(s->file)) {
1244         trace_migration_completion_file_err();
1245         goto fail;
1246     }
1247
1248     migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_COMPLETED);
1249     return;
1250
1251 fail:
1252     migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_FAILED);
1253 }
1254
1255 /*
1256  * Master migration thread on the source VM.
1257  * It drives the migration and pumps the data down the outgoing channel.
1258  */
1259 static void *migration_thread(void *opaque)
1260 {
1261     MigrationState *s = opaque;
1262     int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1263     int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
1264     int64_t initial_bytes = 0;
1265     int64_t max_size = 0;
1266     int64_t start_time = initial_time;
1267     int64_t end_time;
1268     bool old_vm_running = false;
1269
1270     rcu_register_thread();
1271
1272     qemu_savevm_state_header(s->file);
1273     qemu_savevm_state_begin(s->file, &s->params);
1274
1275     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
1276     migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE);
1277
1278     while (s->state == MIGRATION_STATUS_ACTIVE) {
1279         int64_t current_time;
1280         uint64_t pending_size;
1281
1282         if (!qemu_file_rate_limit(s->file)) {
1283             pending_size = qemu_savevm_state_pending(s->file, max_size);
1284             trace_migrate_pending(pending_size, max_size);
1285             if (pending_size && pending_size >= max_size) {
1286                 qemu_savevm_state_iterate(s->file);
1287             } else {
1288                 trace_migration_thread_low_pending(pending_size);
1289                 migration_completion(s, &old_vm_running, &start_time);
1290                 break;
1291             }
1292         }
1293
1294         if (qemu_file_get_error(s->file)) {
1295             migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
1296                               MIGRATION_STATUS_FAILED);
1297             break;
1298         }
1299         current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1300         if (current_time >= initial_time + BUFFER_DELAY) {
1301             uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;
1302             uint64_t time_spent = current_time - initial_time;
1303             double bandwidth = transferred_bytes / time_spent;
1304             max_size = bandwidth * migrate_max_downtime() / 1000000;
1305
1306             s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
1307                     ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
1308
1309             trace_migrate_transferred(transferred_bytes, time_spent,
1310                                       bandwidth, max_size);
1311             /* if we haven't sent anything, we don't want to recalculate
1312                10000 is a small enough number for our purposes */
1313             if (s->dirty_bytes_rate && transferred_bytes > 10000) {
1314                 s->expected_downtime = s->dirty_bytes_rate / bandwidth;
1315             }
1316
1317             qemu_file_reset_rate_limit(s->file);
1318             initial_time = current_time;
1319             initial_bytes = qemu_ftell(s->file);
1320         }
1321         if (qemu_file_rate_limit(s->file)) {
1322             /* usleep expects microseconds */
1323             g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
1324         }
1325     }
1326
1327     /* If we enabled cpu throttling for auto-converge, turn it off. */
1328     cpu_throttle_stop();
1329     end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1330
1331     qemu_mutex_lock_iothread();
1332     qemu_savevm_state_cleanup();
1333     if (s->state == MIGRATION_STATUS_COMPLETED) {
1334         uint64_t transferred_bytes = qemu_ftell(s->file);
1335         s->total_time = end_time - s->total_time;
1336         s->downtime = end_time - start_time;
1337         if (s->total_time) {
1338             s->mbps = (((double) transferred_bytes * 8.0) /
1339                        ((double) s->total_time)) / 1000;
1340         }
1341         runstate_set(RUN_STATE_POSTMIGRATE);
1342     } else {
1343         if (old_vm_running) {
1344             vm_start();
1345         }
1346     }
1347     qemu_bh_schedule(s->cleanup_bh);
1348     qemu_mutex_unlock_iothread();
1349
1350     rcu_unregister_thread();
1351     return NULL;
1352 }
1353
1354 void migrate_fd_connect(MigrationState *s)
1355 {
1356     /* This is a best 1st approximation. ns to ms */
1357     s->expected_downtime = max_downtime/1000000;
1358     s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
1359
1360     qemu_file_set_rate_limit(s->file,
1361                              s->bandwidth_limit / XFER_LIMIT_RATIO);
1362
1363     /* Notify before starting migration thread */
1364     notifier_list_notify(&migration_state_notifiers, s);
1365
1366     migrate_compress_threads_create();
1367     qemu_thread_create(&s->thread, "migration", migration_thread, s,
1368                        QEMU_THREAD_JOINABLE);
1369 }