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/osdep.h" 17 #include "qemu/cutils.h" 18 #include "qemu/error-report.h" 19 #include "qemu/main-loop.h" 20 #include "migration/migration.h" 21 #include "migration/qemu-file.h" 22 #include "sysemu/sysemu.h" 23 #include "block/block.h" 24 #include "qapi/qmp/qerror.h" 25 #include "qapi/util.h" 26 #include "qemu/sockets.h" 27 #include "qemu/rcu.h" 28 #include "migration/block.h" 29 #include "migration/postcopy-ram.h" 30 #include "qemu/thread.h" 31 #include "qmp-commands.h" 32 #include "trace.h" 33 #include "qapi-event.h" 34 #include "qom/cpu.h" 35 #include "exec/memory.h" 36 #include "exec/address-spaces.h" 37 #include "io/channel-buffer.h" 38 #include "io/channel-tls.h" 39 #include "migration/colo.h" 40 41 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ 42 43 /* Amount of time to allocate to each "chunk" of bandwidth-throttled 44 * data. */ 45 #define BUFFER_DELAY 100 46 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) 47 48 /* Time in milliseconds we are allowed to stop the source, 49 * for sending the last part */ 50 #define DEFAULT_MIGRATE_SET_DOWNTIME 300 51 52 /* Default compression thread count */ 53 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8 54 /* Default decompression thread count, usually decompression is at 55 * least 4 times as fast as compression.*/ 56 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2 57 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */ 58 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1 59 /* Define default autoconverge cpu throttle migration parameters */ 60 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20 61 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10 62 63 /* Migration XBZRLE default cache size */ 64 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) 65 66 /* The delay time (in ms) between two COLO checkpoints 67 * Note: Please change this default value to 10000 when we support hybrid mode. 68 */ 69 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200 70 71 static NotifierList migration_state_notifiers = 72 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); 73 74 static bool deferred_incoming; 75 76 /* 77 * Current state of incoming postcopy; note this is not part of 78 * MigrationIncomingState since it's state is used during cleanup 79 * at the end as MIS is being freed. 80 */ 81 static PostcopyState incoming_postcopy_state; 82 83 /* When we add fault tolerance, we could have several 84 migrations at once. For now we don't need to add 85 dynamic creation of migration */ 86 87 /* For outgoing */ 88 MigrationState *migrate_get_current(void) 89 { 90 static bool once; 91 static MigrationState current_migration = { 92 .state = MIGRATION_STATUS_NONE, 93 .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE, 94 .mbps = -1, 95 .parameters = { 96 .compress_level = DEFAULT_MIGRATE_COMPRESS_LEVEL, 97 .compress_threads = DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT, 98 .decompress_threads = DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT, 99 .cpu_throttle_initial = DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL, 100 .cpu_throttle_increment = DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT, 101 .max_bandwidth = MAX_THROTTLE, 102 .downtime_limit = DEFAULT_MIGRATE_SET_DOWNTIME, 103 .x_checkpoint_delay = DEFAULT_MIGRATE_X_CHECKPOINT_DELAY, 104 }, 105 }; 106 107 if (!once) { 108 qemu_mutex_init(¤t_migration.src_page_req_mutex); 109 once = true; 110 } 111 return ¤t_migration; 112 } 113 114 MigrationIncomingState *migration_incoming_get_current(void) 115 { 116 static bool once; 117 static MigrationIncomingState mis_current; 118 119 if (!once) { 120 mis_current.state = MIGRATION_STATUS_NONE; 121 memset(&mis_current, 0, sizeof(MigrationIncomingState)); 122 QLIST_INIT(&mis_current.loadvm_handlers); 123 qemu_mutex_init(&mis_current.rp_mutex); 124 qemu_event_init(&mis_current.main_thread_load_event, false); 125 once = true; 126 } 127 return &mis_current; 128 } 129 130 void migration_incoming_state_destroy(void) 131 { 132 struct MigrationIncomingState *mis = migration_incoming_get_current(); 133 134 qemu_event_destroy(&mis->main_thread_load_event); 135 loadvm_free_handlers(mis); 136 } 137 138 139 typedef struct { 140 bool optional; 141 uint32_t size; 142 uint8_t runstate[100]; 143 RunState state; 144 bool received; 145 } GlobalState; 146 147 static GlobalState global_state; 148 149 int global_state_store(void) 150 { 151 if (!runstate_store((char *)global_state.runstate, 152 sizeof(global_state.runstate))) { 153 error_report("runstate name too big: %s", global_state.runstate); 154 trace_migrate_state_too_big(); 155 return -EINVAL; 156 } 157 return 0; 158 } 159 160 void global_state_store_running(void) 161 { 162 const char *state = RunState_lookup[RUN_STATE_RUNNING]; 163 strncpy((char *)global_state.runstate, 164 state, sizeof(global_state.runstate)); 165 } 166 167 static bool global_state_received(void) 168 { 169 return global_state.received; 170 } 171 172 static RunState global_state_get_runstate(void) 173 { 174 return global_state.state; 175 } 176 177 void global_state_set_optional(void) 178 { 179 global_state.optional = true; 180 } 181 182 static bool global_state_needed(void *opaque) 183 { 184 GlobalState *s = opaque; 185 char *runstate = (char *)s->runstate; 186 187 /* If it is not optional, it is mandatory */ 188 189 if (s->optional == false) { 190 return true; 191 } 192 193 /* If state is running or paused, it is not needed */ 194 195 if (strcmp(runstate, "running") == 0 || 196 strcmp(runstate, "paused") == 0) { 197 return false; 198 } 199 200 /* for any other state it is needed */ 201 return true; 202 } 203 204 static int global_state_post_load(void *opaque, int version_id) 205 { 206 GlobalState *s = opaque; 207 Error *local_err = NULL; 208 int r; 209 char *runstate = (char *)s->runstate; 210 211 s->received = true; 212 trace_migrate_global_state_post_load(runstate); 213 214 r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE__MAX, 215 -1, &local_err); 216 217 if (r == -1) { 218 if (local_err) { 219 error_report_err(local_err); 220 } 221 return -EINVAL; 222 } 223 s->state = r; 224 225 return 0; 226 } 227 228 static void global_state_pre_save(void *opaque) 229 { 230 GlobalState *s = opaque; 231 232 trace_migrate_global_state_pre_save((char *)s->runstate); 233 s->size = strlen((char *)s->runstate) + 1; 234 } 235 236 static const VMStateDescription vmstate_globalstate = { 237 .name = "globalstate", 238 .version_id = 1, 239 .minimum_version_id = 1, 240 .post_load = global_state_post_load, 241 .pre_save = global_state_pre_save, 242 .needed = global_state_needed, 243 .fields = (VMStateField[]) { 244 VMSTATE_UINT32(size, GlobalState), 245 VMSTATE_BUFFER(runstate, GlobalState), 246 VMSTATE_END_OF_LIST() 247 }, 248 }; 249 250 void register_global_state(void) 251 { 252 /* We would use it independently that we receive it */ 253 strcpy((char *)&global_state.runstate, ""); 254 global_state.received = false; 255 vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); 256 } 257 258 static void migrate_generate_event(int new_state) 259 { 260 if (migrate_use_events()) { 261 qapi_event_send_migration(new_state, &error_abort); 262 } 263 } 264 265 /* 266 * Called on -incoming with a defer: uri. 267 * The migration can be started later after any parameters have been 268 * changed. 269 */ 270 static void deferred_incoming_migration(Error **errp) 271 { 272 if (deferred_incoming) { 273 error_setg(errp, "Incoming migration already deferred"); 274 } 275 deferred_incoming = true; 276 } 277 278 /* Request a range of pages from the source VM at the given 279 * start address. 280 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same 281 * as the last request (a name must have been given previously) 282 * Start: Address offset within the RB 283 * Len: Length in bytes required - must be a multiple of pagesize 284 */ 285 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, 286 ram_addr_t start, size_t len) 287 { 288 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */ 289 size_t msglen = 12; /* start + len */ 290 291 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); 292 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); 293 294 if (rbname) { 295 int rbname_len = strlen(rbname); 296 assert(rbname_len < 256); 297 298 bufc[msglen++] = rbname_len; 299 memcpy(bufc + msglen, rbname, rbname_len); 300 msglen += rbname_len; 301 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc); 302 } else { 303 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc); 304 } 305 } 306 307 void qemu_start_incoming_migration(const char *uri, Error **errp) 308 { 309 const char *p; 310 311 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort); 312 if (!strcmp(uri, "defer")) { 313 deferred_incoming_migration(errp); 314 } else if (strstart(uri, "tcp:", &p)) { 315 tcp_start_incoming_migration(p, errp); 316 #ifdef CONFIG_RDMA 317 } else if (strstart(uri, "rdma:", &p)) { 318 rdma_start_incoming_migration(p, errp); 319 #endif 320 } else if (strstart(uri, "exec:", &p)) { 321 exec_start_incoming_migration(p, errp); 322 } else if (strstart(uri, "unix:", &p)) { 323 unix_start_incoming_migration(p, errp); 324 } else if (strstart(uri, "fd:", &p)) { 325 fd_start_incoming_migration(p, errp); 326 } else { 327 error_setg(errp, "unknown migration protocol: %s", uri); 328 } 329 } 330 331 static void process_incoming_migration_bh(void *opaque) 332 { 333 Error *local_err = NULL; 334 MigrationIncomingState *mis = opaque; 335 336 /* Make sure all file formats flush their mutable metadata */ 337 bdrv_invalidate_cache_all(&local_err); 338 if (local_err) { 339 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 340 MIGRATION_STATUS_FAILED); 341 error_report_err(local_err); 342 migrate_decompress_threads_join(); 343 exit(EXIT_FAILURE); 344 } 345 346 /* 347 * This must happen after all error conditions are dealt with and 348 * we're sure the VM is going to be running on this host. 349 */ 350 qemu_announce_self(); 351 352 /* If global state section was not received or we are in running 353 state, we need to obey autostart. Any other state is set with 354 runstate_set. */ 355 356 if (!global_state_received() || 357 global_state_get_runstate() == RUN_STATE_RUNNING) { 358 if (autostart) { 359 vm_start(); 360 } else { 361 runstate_set(RUN_STATE_PAUSED); 362 } 363 } else { 364 runstate_set(global_state_get_runstate()); 365 } 366 migrate_decompress_threads_join(); 367 /* 368 * This must happen after any state changes since as soon as an external 369 * observer sees this event they might start to prod at the VM assuming 370 * it's ready to use. 371 */ 372 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 373 MIGRATION_STATUS_COMPLETED); 374 qemu_bh_delete(mis->bh); 375 migration_incoming_state_destroy(); 376 } 377 378 static void process_incoming_migration_co(void *opaque) 379 { 380 QEMUFile *f = opaque; 381 MigrationIncomingState *mis = migration_incoming_get_current(); 382 PostcopyState ps; 383 int ret; 384 385 mis->from_src_file = f; 386 postcopy_state_set(POSTCOPY_INCOMING_NONE); 387 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE, 388 MIGRATION_STATUS_ACTIVE); 389 ret = qemu_loadvm_state(f); 390 391 ps = postcopy_state_get(); 392 trace_process_incoming_migration_co_end(ret, ps); 393 if (ps != POSTCOPY_INCOMING_NONE) { 394 if (ps == POSTCOPY_INCOMING_ADVISE) { 395 /* 396 * Where a migration had postcopy enabled (and thus went to advise) 397 * but managed to complete within the precopy period, we can use 398 * the normal exit. 399 */ 400 postcopy_ram_incoming_cleanup(mis); 401 } else if (ret >= 0) { 402 /* 403 * Postcopy was started, cleanup should happen at the end of the 404 * postcopy thread. 405 */ 406 trace_process_incoming_migration_co_postcopy_end_main(); 407 return; 408 } 409 /* Else if something went wrong then just fall out of the normal exit */ 410 } 411 412 /* we get COLO info, and know if we are in COLO mode */ 413 if (!ret && migration_incoming_enable_colo()) { 414 mis->migration_incoming_co = qemu_coroutine_self(); 415 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming", 416 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE); 417 mis->have_colo_incoming_thread = true; 418 qemu_coroutine_yield(); 419 420 /* Wait checkpoint incoming thread exit before free resource */ 421 qemu_thread_join(&mis->colo_incoming_thread); 422 } 423 424 qemu_fclose(f); 425 free_xbzrle_decoded_buf(); 426 427 if (ret < 0) { 428 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 429 MIGRATION_STATUS_FAILED); 430 error_report("load of migration failed: %s", strerror(-ret)); 431 migrate_decompress_threads_join(); 432 exit(EXIT_FAILURE); 433 } 434 435 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); 436 qemu_bh_schedule(mis->bh); 437 } 438 439 void migration_fd_process_incoming(QEMUFile *f) 440 { 441 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, f); 442 443 migrate_decompress_threads_create(); 444 qemu_file_set_blocking(f, false); 445 qemu_coroutine_enter(co); 446 } 447 448 449 void migration_channel_process_incoming(MigrationState *s, 450 QIOChannel *ioc) 451 { 452 trace_migration_set_incoming_channel( 453 ioc, object_get_typename(OBJECT(ioc))); 454 455 if (s->parameters.tls_creds && 456 !object_dynamic_cast(OBJECT(ioc), 457 TYPE_QIO_CHANNEL_TLS)) { 458 Error *local_err = NULL; 459 migration_tls_channel_process_incoming(s, ioc, &local_err); 460 if (local_err) { 461 error_report_err(local_err); 462 } 463 } else { 464 QEMUFile *f = qemu_fopen_channel_input(ioc); 465 migration_fd_process_incoming(f); 466 } 467 } 468 469 470 void migration_channel_connect(MigrationState *s, 471 QIOChannel *ioc, 472 const char *hostname) 473 { 474 trace_migration_set_outgoing_channel( 475 ioc, object_get_typename(OBJECT(ioc)), hostname); 476 477 if (s->parameters.tls_creds && 478 !object_dynamic_cast(OBJECT(ioc), 479 TYPE_QIO_CHANNEL_TLS)) { 480 Error *local_err = NULL; 481 migration_tls_channel_connect(s, ioc, hostname, &local_err); 482 if (local_err) { 483 migrate_fd_error(s, local_err); 484 error_free(local_err); 485 } 486 } else { 487 QEMUFile *f = qemu_fopen_channel_output(ioc); 488 489 s->to_dst_file = f; 490 491 migrate_fd_connect(s); 492 } 493 } 494 495 496 /* 497 * Send a message on the return channel back to the source 498 * of the migration. 499 */ 500 void migrate_send_rp_message(MigrationIncomingState *mis, 501 enum mig_rp_message_type message_type, 502 uint16_t len, void *data) 503 { 504 trace_migrate_send_rp_message((int)message_type, len); 505 qemu_mutex_lock(&mis->rp_mutex); 506 qemu_put_be16(mis->to_src_file, (unsigned int)message_type); 507 qemu_put_be16(mis->to_src_file, len); 508 qemu_put_buffer(mis->to_src_file, data, len); 509 qemu_fflush(mis->to_src_file); 510 qemu_mutex_unlock(&mis->rp_mutex); 511 } 512 513 /* 514 * Send a 'SHUT' message on the return channel with the given value 515 * to indicate that we've finished with the RP. Non-0 value indicates 516 * error. 517 */ 518 void migrate_send_rp_shut(MigrationIncomingState *mis, 519 uint32_t value) 520 { 521 uint32_t buf; 522 523 buf = cpu_to_be32(value); 524 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); 525 } 526 527 /* 528 * Send a 'PONG' message on the return channel with the given value 529 * (normally in response to a 'PING') 530 */ 531 void migrate_send_rp_pong(MigrationIncomingState *mis, 532 uint32_t value) 533 { 534 uint32_t buf; 535 536 buf = cpu_to_be32(value); 537 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); 538 } 539 540 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) 541 { 542 MigrationCapabilityStatusList *head = NULL; 543 MigrationCapabilityStatusList *caps; 544 MigrationState *s = migrate_get_current(); 545 int i; 546 547 caps = NULL; /* silence compiler warning */ 548 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 549 if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) { 550 continue; 551 } 552 if (head == NULL) { 553 head = g_malloc0(sizeof(*caps)); 554 caps = head; 555 } else { 556 caps->next = g_malloc0(sizeof(*caps)); 557 caps = caps->next; 558 } 559 caps->value = 560 g_malloc(sizeof(*caps->value)); 561 caps->value->capability = i; 562 caps->value->state = s->enabled_capabilities[i]; 563 } 564 565 return head; 566 } 567 568 MigrationParameters *qmp_query_migrate_parameters(Error **errp) 569 { 570 MigrationParameters *params; 571 MigrationState *s = migrate_get_current(); 572 573 params = g_malloc0(sizeof(*params)); 574 params->has_compress_level = true; 575 params->compress_level = s->parameters.compress_level; 576 params->has_compress_threads = true; 577 params->compress_threads = s->parameters.compress_threads; 578 params->has_decompress_threads = true; 579 params->decompress_threads = s->parameters.decompress_threads; 580 params->has_cpu_throttle_initial = true; 581 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; 582 params->has_cpu_throttle_increment = true; 583 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; 584 params->has_tls_creds = !!s->parameters.tls_creds; 585 params->tls_creds = g_strdup(s->parameters.tls_creds); 586 params->has_tls_hostname = !!s->parameters.tls_hostname; 587 params->tls_hostname = g_strdup(s->parameters.tls_hostname); 588 params->has_max_bandwidth = true; 589 params->max_bandwidth = s->parameters.max_bandwidth; 590 params->has_downtime_limit = true; 591 params->downtime_limit = s->parameters.downtime_limit; 592 params->has_x_checkpoint_delay = true; 593 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay; 594 595 return params; 596 } 597 598 /* 599 * Return true if we're already in the middle of a migration 600 * (i.e. any of the active or setup states) 601 */ 602 static bool migration_is_setup_or_active(int state) 603 { 604 switch (state) { 605 case MIGRATION_STATUS_ACTIVE: 606 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 607 case MIGRATION_STATUS_SETUP: 608 return true; 609 610 default: 611 return false; 612 613 } 614 } 615 616 static void get_xbzrle_cache_stats(MigrationInfo *info) 617 { 618 if (migrate_use_xbzrle()) { 619 info->has_xbzrle_cache = true; 620 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); 621 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); 622 info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred(); 623 info->xbzrle_cache->pages = xbzrle_mig_pages_transferred(); 624 info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss(); 625 info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate(); 626 info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow(); 627 } 628 } 629 630 static void populate_ram_info(MigrationInfo *info, MigrationState *s) 631 { 632 info->has_ram = true; 633 info->ram = g_malloc0(sizeof(*info->ram)); 634 info->ram->transferred = ram_bytes_transferred(); 635 info->ram->total = ram_bytes_total(); 636 info->ram->duplicate = dup_mig_pages_transferred(); 637 info->ram->skipped = skipped_mig_pages_transferred(); 638 info->ram->normal = norm_mig_pages_transferred(); 639 info->ram->normal_bytes = norm_mig_bytes_transferred(); 640 info->ram->mbps = s->mbps; 641 info->ram->dirty_sync_count = s->dirty_sync_count; 642 info->ram->postcopy_requests = s->postcopy_requests; 643 644 if (s->state != MIGRATION_STATUS_COMPLETED) { 645 info->ram->remaining = ram_bytes_remaining(); 646 info->ram->dirty_pages_rate = s->dirty_pages_rate; 647 } 648 } 649 650 MigrationInfo *qmp_query_migrate(Error **errp) 651 { 652 MigrationInfo *info = g_malloc0(sizeof(*info)); 653 MigrationState *s = migrate_get_current(); 654 655 switch (s->state) { 656 case MIGRATION_STATUS_NONE: 657 /* no migration has happened ever */ 658 break; 659 case MIGRATION_STATUS_SETUP: 660 info->has_status = true; 661 info->has_total_time = false; 662 break; 663 case MIGRATION_STATUS_ACTIVE: 664 case MIGRATION_STATUS_CANCELLING: 665 info->has_status = true; 666 info->has_total_time = true; 667 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 668 - s->total_time; 669 info->has_expected_downtime = true; 670 info->expected_downtime = s->expected_downtime; 671 info->has_setup_time = true; 672 info->setup_time = s->setup_time; 673 674 populate_ram_info(info, s); 675 676 if (blk_mig_active()) { 677 info->has_disk = true; 678 info->disk = g_malloc0(sizeof(*info->disk)); 679 info->disk->transferred = blk_mig_bytes_transferred(); 680 info->disk->remaining = blk_mig_bytes_remaining(); 681 info->disk->total = blk_mig_bytes_total(); 682 } 683 684 if (cpu_throttle_active()) { 685 info->has_cpu_throttle_percentage = true; 686 info->cpu_throttle_percentage = cpu_throttle_get_percentage(); 687 } 688 689 get_xbzrle_cache_stats(info); 690 break; 691 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 692 /* Mostly the same as active; TODO add some postcopy stats */ 693 info->has_status = true; 694 info->has_total_time = true; 695 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 696 - s->total_time; 697 info->has_expected_downtime = true; 698 info->expected_downtime = s->expected_downtime; 699 info->has_setup_time = true; 700 info->setup_time = s->setup_time; 701 702 populate_ram_info(info, s); 703 704 if (blk_mig_active()) { 705 info->has_disk = true; 706 info->disk = g_malloc0(sizeof(*info->disk)); 707 info->disk->transferred = blk_mig_bytes_transferred(); 708 info->disk->remaining = blk_mig_bytes_remaining(); 709 info->disk->total = blk_mig_bytes_total(); 710 } 711 712 get_xbzrle_cache_stats(info); 713 break; 714 case MIGRATION_STATUS_COLO: 715 info->has_status = true; 716 /* TODO: display COLO specific information (checkpoint info etc.) */ 717 break; 718 case MIGRATION_STATUS_COMPLETED: 719 get_xbzrle_cache_stats(info); 720 721 info->has_status = true; 722 info->has_total_time = true; 723 info->total_time = s->total_time; 724 info->has_downtime = true; 725 info->downtime = s->downtime; 726 info->has_setup_time = true; 727 info->setup_time = s->setup_time; 728 729 populate_ram_info(info, s); 730 break; 731 case MIGRATION_STATUS_FAILED: 732 info->has_status = true; 733 if (s->error) { 734 info->has_error_desc = true; 735 info->error_desc = g_strdup(error_get_pretty(s->error)); 736 } 737 break; 738 case MIGRATION_STATUS_CANCELLED: 739 info->has_status = true; 740 break; 741 } 742 info->status = s->state; 743 744 return info; 745 } 746 747 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 748 Error **errp) 749 { 750 MigrationState *s = migrate_get_current(); 751 MigrationCapabilityStatusList *cap; 752 bool old_postcopy_cap = migrate_postcopy_ram(); 753 754 if (migration_is_setup_or_active(s->state)) { 755 error_setg(errp, QERR_MIGRATION_ACTIVE); 756 return; 757 } 758 759 for (cap = params; cap; cap = cap->next) { 760 if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) { 761 if (!colo_supported()) { 762 error_setg(errp, "COLO is not currently supported, please" 763 " configure with --enable-colo option in order to" 764 " support COLO feature"); 765 continue; 766 } 767 } 768 s->enabled_capabilities[cap->value->capability] = cap->value->state; 769 } 770 771 if (migrate_postcopy_ram()) { 772 if (migrate_use_compression()) { 773 /* The decompression threads asynchronously write into RAM 774 * rather than use the atomic copies needed to avoid 775 * userfaulting. It should be possible to fix the decompression 776 * threads for compatibility in future. 777 */ 778 error_report("Postcopy is not currently compatible with " 779 "compression"); 780 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] = 781 false; 782 } 783 /* This check is reasonably expensive, so only when it's being 784 * set the first time, also it's only the destination that needs 785 * special support. 786 */ 787 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) && 788 !postcopy_ram_supported_by_host()) { 789 /* postcopy_ram_supported_by_host will have emitted a more 790 * detailed message 791 */ 792 error_report("Postcopy is not supported"); 793 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] = 794 false; 795 } 796 } 797 } 798 799 void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp) 800 { 801 MigrationState *s = migrate_get_current(); 802 803 if (params->has_compress_level && 804 (params->compress_level < 0 || params->compress_level > 9)) { 805 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level", 806 "is invalid, it should be in the range of 0 to 9"); 807 return; 808 } 809 if (params->has_compress_threads && 810 (params->compress_threads < 1 || params->compress_threads > 255)) { 811 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 812 "compress_threads", 813 "is invalid, it should be in the range of 1 to 255"); 814 return; 815 } 816 if (params->has_decompress_threads && 817 (params->decompress_threads < 1 || params->decompress_threads > 255)) { 818 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 819 "decompress_threads", 820 "is invalid, it should be in the range of 1 to 255"); 821 return; 822 } 823 if (params->has_cpu_throttle_initial && 824 (params->cpu_throttle_initial < 1 || 825 params->cpu_throttle_initial > 99)) { 826 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 827 "cpu_throttle_initial", 828 "an integer in the range of 1 to 99"); 829 return; 830 } 831 if (params->has_cpu_throttle_increment && 832 (params->cpu_throttle_increment < 1 || 833 params->cpu_throttle_increment > 99)) { 834 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 835 "cpu_throttle_increment", 836 "an integer in the range of 1 to 99"); 837 return; 838 } 839 if (params->has_max_bandwidth && 840 (params->max_bandwidth < 0 || params->max_bandwidth > SIZE_MAX)) { 841 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the" 842 " range of 0 to %zu bytes/second", SIZE_MAX); 843 return; 844 } 845 if (params->has_downtime_limit && 846 (params->downtime_limit < 0 || params->downtime_limit > 2000000)) { 847 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 848 "downtime_limit", 849 "an integer in the range of 0 to 2000000 milliseconds"); 850 return; 851 } 852 if (params->has_x_checkpoint_delay && (params->x_checkpoint_delay < 0)) { 853 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 854 "x_checkpoint_delay", 855 "is invalid, it should be positive"); 856 } 857 858 if (params->has_compress_level) { 859 s->parameters.compress_level = params->compress_level; 860 } 861 if (params->has_compress_threads) { 862 s->parameters.compress_threads = params->compress_threads; 863 } 864 if (params->has_decompress_threads) { 865 s->parameters.decompress_threads = params->decompress_threads; 866 } 867 if (params->has_cpu_throttle_initial) { 868 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial; 869 } 870 if (params->has_cpu_throttle_increment) { 871 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; 872 } 873 if (params->has_tls_creds) { 874 g_free(s->parameters.tls_creds); 875 s->parameters.tls_creds = g_strdup(params->tls_creds); 876 } 877 if (params->has_tls_hostname) { 878 g_free(s->parameters.tls_hostname); 879 s->parameters.tls_hostname = g_strdup(params->tls_hostname); 880 } 881 if (params->has_max_bandwidth) { 882 s->parameters.max_bandwidth = params->max_bandwidth; 883 if (s->to_dst_file) { 884 qemu_file_set_rate_limit(s->to_dst_file, 885 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 886 } 887 } 888 if (params->has_downtime_limit) { 889 s->parameters.downtime_limit = params->downtime_limit; 890 } 891 892 if (params->has_x_checkpoint_delay) { 893 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay; 894 if (migration_in_colo_state()) { 895 colo_checkpoint_notify(s); 896 } 897 } 898 } 899 900 901 void qmp_migrate_start_postcopy(Error **errp) 902 { 903 MigrationState *s = migrate_get_current(); 904 905 if (!migrate_postcopy_ram()) { 906 error_setg(errp, "Enable postcopy with migrate_set_capability before" 907 " the start of migration"); 908 return; 909 } 910 911 if (s->state == MIGRATION_STATUS_NONE) { 912 error_setg(errp, "Postcopy must be started after migration has been" 913 " started"); 914 return; 915 } 916 /* 917 * we don't error if migration has finished since that would be racy 918 * with issuing this command. 919 */ 920 atomic_set(&s->start_postcopy, true); 921 } 922 923 /* shared migration helpers */ 924 925 void migrate_set_state(int *state, int old_state, int new_state) 926 { 927 if (atomic_cmpxchg(state, old_state, new_state) == old_state) { 928 trace_migrate_set_state(new_state); 929 migrate_generate_event(new_state); 930 } 931 } 932 933 static void migrate_fd_cleanup(void *opaque) 934 { 935 MigrationState *s = opaque; 936 937 qemu_bh_delete(s->cleanup_bh); 938 s->cleanup_bh = NULL; 939 940 flush_page_queue(s); 941 942 if (s->to_dst_file) { 943 trace_migrate_fd_cleanup(); 944 qemu_mutex_unlock_iothread(); 945 if (s->migration_thread_running) { 946 qemu_thread_join(&s->thread); 947 s->migration_thread_running = false; 948 } 949 qemu_mutex_lock_iothread(); 950 951 migrate_compress_threads_join(); 952 qemu_fclose(s->to_dst_file); 953 s->to_dst_file = NULL; 954 } 955 956 assert((s->state != MIGRATION_STATUS_ACTIVE) && 957 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE)); 958 959 if (s->state == MIGRATION_STATUS_CANCELLING) { 960 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING, 961 MIGRATION_STATUS_CANCELLED); 962 } 963 964 notifier_list_notify(&migration_state_notifiers, s); 965 } 966 967 void migrate_fd_error(MigrationState *s, const Error *error) 968 { 969 trace_migrate_fd_error(error_get_pretty(error)); 970 assert(s->to_dst_file == NULL); 971 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 972 MIGRATION_STATUS_FAILED); 973 if (!s->error) { 974 s->error = error_copy(error); 975 } 976 notifier_list_notify(&migration_state_notifiers, s); 977 } 978 979 static void migrate_fd_cancel(MigrationState *s) 980 { 981 int old_state ; 982 QEMUFile *f = migrate_get_current()->to_dst_file; 983 trace_migrate_fd_cancel(); 984 985 if (s->rp_state.from_dst_file) { 986 /* shutdown the rp socket, so causing the rp thread to shutdown */ 987 qemu_file_shutdown(s->rp_state.from_dst_file); 988 } 989 990 do { 991 old_state = s->state; 992 if (!migration_is_setup_or_active(old_state)) { 993 break; 994 } 995 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING); 996 } while (s->state != MIGRATION_STATUS_CANCELLING); 997 998 /* 999 * If we're unlucky the migration code might be stuck somewhere in a 1000 * send/write while the network has failed and is waiting to timeout; 1001 * if we've got shutdown(2) available then we can force it to quit. 1002 * The outgoing qemu file gets closed in migrate_fd_cleanup that is 1003 * called in a bh, so there is no race against this cancel. 1004 */ 1005 if (s->state == MIGRATION_STATUS_CANCELLING && f) { 1006 qemu_file_shutdown(f); 1007 } 1008 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) { 1009 Error *local_err = NULL; 1010 1011 bdrv_invalidate_cache_all(&local_err); 1012 if (local_err) { 1013 error_report_err(local_err); 1014 } else { 1015 s->block_inactive = false; 1016 } 1017 } 1018 } 1019 1020 void add_migration_state_change_notifier(Notifier *notify) 1021 { 1022 notifier_list_add(&migration_state_notifiers, notify); 1023 } 1024 1025 void remove_migration_state_change_notifier(Notifier *notify) 1026 { 1027 notifier_remove(notify); 1028 } 1029 1030 bool migration_in_setup(MigrationState *s) 1031 { 1032 return s->state == MIGRATION_STATUS_SETUP; 1033 } 1034 1035 bool migration_has_finished(MigrationState *s) 1036 { 1037 return s->state == MIGRATION_STATUS_COMPLETED; 1038 } 1039 1040 bool migration_has_failed(MigrationState *s) 1041 { 1042 return (s->state == MIGRATION_STATUS_CANCELLED || 1043 s->state == MIGRATION_STATUS_FAILED); 1044 } 1045 1046 bool migration_in_postcopy(MigrationState *s) 1047 { 1048 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 1049 } 1050 1051 bool migration_in_postcopy_after_devices(MigrationState *s) 1052 { 1053 return migration_in_postcopy(s) && s->postcopy_after_devices; 1054 } 1055 1056 bool migration_is_idle(MigrationState *s) 1057 { 1058 if (!s) { 1059 s = migrate_get_current(); 1060 } 1061 1062 switch (s->state) { 1063 case MIGRATION_STATUS_NONE: 1064 case MIGRATION_STATUS_CANCELLED: 1065 case MIGRATION_STATUS_COMPLETED: 1066 case MIGRATION_STATUS_FAILED: 1067 return true; 1068 case MIGRATION_STATUS_SETUP: 1069 case MIGRATION_STATUS_CANCELLING: 1070 case MIGRATION_STATUS_ACTIVE: 1071 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 1072 case MIGRATION_STATUS_COLO: 1073 return false; 1074 case MIGRATION_STATUS__MAX: 1075 g_assert_not_reached(); 1076 } 1077 1078 return false; 1079 } 1080 1081 MigrationState *migrate_init(const MigrationParams *params) 1082 { 1083 MigrationState *s = migrate_get_current(); 1084 1085 /* 1086 * Reinitialise all migration state, except 1087 * parameters/capabilities that the user set, and 1088 * locks. 1089 */ 1090 s->bytes_xfer = 0; 1091 s->xfer_limit = 0; 1092 s->cleanup_bh = 0; 1093 s->to_dst_file = NULL; 1094 s->state = MIGRATION_STATUS_NONE; 1095 s->params = *params; 1096 s->rp_state.from_dst_file = NULL; 1097 s->rp_state.error = false; 1098 s->mbps = 0.0; 1099 s->downtime = 0; 1100 s->expected_downtime = 0; 1101 s->dirty_pages_rate = 0; 1102 s->dirty_bytes_rate = 0; 1103 s->setup_time = 0; 1104 s->dirty_sync_count = 0; 1105 s->start_postcopy = false; 1106 s->postcopy_after_devices = false; 1107 s->postcopy_requests = 0; 1108 s->migration_thread_running = false; 1109 s->last_req_rb = NULL; 1110 error_free(s->error); 1111 s->error = NULL; 1112 1113 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); 1114 1115 QSIMPLEQ_INIT(&s->src_page_requests); 1116 1117 s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1118 return s; 1119 } 1120 1121 static GSList *migration_blockers; 1122 1123 int migrate_add_blocker(Error *reason, Error **errp) 1124 { 1125 if (only_migratable) { 1126 error_propagate(errp, error_copy(reason)); 1127 error_prepend(errp, "disallowing migration blocker " 1128 "(--only_migratable) for: "); 1129 return -EACCES; 1130 } 1131 1132 if (migration_is_idle(NULL)) { 1133 migration_blockers = g_slist_prepend(migration_blockers, reason); 1134 return 0; 1135 } 1136 1137 error_propagate(errp, error_copy(reason)); 1138 error_prepend(errp, "disallowing migration blocker (migration in " 1139 "progress) for: "); 1140 return -EBUSY; 1141 } 1142 1143 void migrate_del_blocker(Error *reason) 1144 { 1145 migration_blockers = g_slist_remove(migration_blockers, reason); 1146 } 1147 1148 void qmp_migrate_incoming(const char *uri, Error **errp) 1149 { 1150 Error *local_err = NULL; 1151 static bool once = true; 1152 1153 if (!deferred_incoming) { 1154 error_setg(errp, "For use with '-incoming defer'"); 1155 return; 1156 } 1157 if (!once) { 1158 error_setg(errp, "The incoming migration has already been started"); 1159 } 1160 1161 qemu_start_incoming_migration(uri, &local_err); 1162 1163 if (local_err) { 1164 error_propagate(errp, local_err); 1165 return; 1166 } 1167 1168 once = false; 1169 } 1170 1171 bool migration_is_blocked(Error **errp) 1172 { 1173 if (qemu_savevm_state_blocked(errp)) { 1174 return true; 1175 } 1176 1177 if (migration_blockers) { 1178 *errp = error_copy(migration_blockers->data); 1179 return true; 1180 } 1181 1182 return false; 1183 } 1184 1185 void qmp_migrate(const char *uri, bool has_blk, bool blk, 1186 bool has_inc, bool inc, bool has_detach, bool detach, 1187 Error **errp) 1188 { 1189 Error *local_err = NULL; 1190 MigrationState *s = migrate_get_current(); 1191 MigrationParams params; 1192 const char *p; 1193 1194 params.blk = has_blk && blk; 1195 params.shared = has_inc && inc; 1196 1197 if (migration_is_setup_or_active(s->state) || 1198 s->state == MIGRATION_STATUS_CANCELLING || 1199 s->state == MIGRATION_STATUS_COLO) { 1200 error_setg(errp, QERR_MIGRATION_ACTIVE); 1201 return; 1202 } 1203 if (runstate_check(RUN_STATE_INMIGRATE)) { 1204 error_setg(errp, "Guest is waiting for an incoming migration"); 1205 return; 1206 } 1207 1208 if (migration_is_blocked(errp)) { 1209 return; 1210 } 1211 1212 s = migrate_init(¶ms); 1213 1214 if (strstart(uri, "tcp:", &p)) { 1215 tcp_start_outgoing_migration(s, p, &local_err); 1216 #ifdef CONFIG_RDMA 1217 } else if (strstart(uri, "rdma:", &p)) { 1218 rdma_start_outgoing_migration(s, p, &local_err); 1219 #endif 1220 } else if (strstart(uri, "exec:", &p)) { 1221 exec_start_outgoing_migration(s, p, &local_err); 1222 } else if (strstart(uri, "unix:", &p)) { 1223 unix_start_outgoing_migration(s, p, &local_err); 1224 } else if (strstart(uri, "fd:", &p)) { 1225 fd_start_outgoing_migration(s, p, &local_err); 1226 } else { 1227 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", 1228 "a valid migration protocol"); 1229 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1230 MIGRATION_STATUS_FAILED); 1231 return; 1232 } 1233 1234 if (local_err) { 1235 migrate_fd_error(s, local_err); 1236 error_propagate(errp, local_err); 1237 return; 1238 } 1239 } 1240 1241 void qmp_migrate_cancel(Error **errp) 1242 { 1243 migrate_fd_cancel(migrate_get_current()); 1244 } 1245 1246 void qmp_migrate_set_cache_size(int64_t value, Error **errp) 1247 { 1248 MigrationState *s = migrate_get_current(); 1249 int64_t new_size; 1250 1251 /* Check for truncation */ 1252 if (value != (size_t)value) { 1253 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1254 "exceeding address space"); 1255 return; 1256 } 1257 1258 /* Cache should not be larger than guest ram size */ 1259 if (value > ram_bytes_total()) { 1260 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1261 "exceeds guest ram size "); 1262 return; 1263 } 1264 1265 new_size = xbzrle_cache_resize(value); 1266 if (new_size < 0) { 1267 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1268 "is smaller than page size"); 1269 return; 1270 } 1271 1272 s->xbzrle_cache_size = new_size; 1273 } 1274 1275 int64_t qmp_query_migrate_cache_size(Error **errp) 1276 { 1277 return migrate_xbzrle_cache_size(); 1278 } 1279 1280 void qmp_migrate_set_speed(int64_t value, Error **errp) 1281 { 1282 MigrationParameters p = { 1283 .has_max_bandwidth = true, 1284 .max_bandwidth = value, 1285 }; 1286 1287 qmp_migrate_set_parameters(&p, errp); 1288 } 1289 1290 void qmp_migrate_set_downtime(double value, Error **errp) 1291 { 1292 value *= 1000; /* Convert to milliseconds */ 1293 value = MAX(0, MIN(INT64_MAX, value)); 1294 1295 MigrationParameters p = { 1296 .has_downtime_limit = true, 1297 .downtime_limit = value, 1298 }; 1299 1300 qmp_migrate_set_parameters(&p, errp); 1301 } 1302 1303 bool migrate_release_ram(void) 1304 { 1305 MigrationState *s; 1306 1307 s = migrate_get_current(); 1308 1309 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM]; 1310 } 1311 1312 bool migrate_postcopy_ram(void) 1313 { 1314 MigrationState *s; 1315 1316 s = migrate_get_current(); 1317 1318 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 1319 } 1320 1321 bool migrate_auto_converge(void) 1322 { 1323 MigrationState *s; 1324 1325 s = migrate_get_current(); 1326 1327 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; 1328 } 1329 1330 bool migrate_zero_blocks(void) 1331 { 1332 MigrationState *s; 1333 1334 s = migrate_get_current(); 1335 1336 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; 1337 } 1338 1339 bool migrate_use_compression(void) 1340 { 1341 MigrationState *s; 1342 1343 s = migrate_get_current(); 1344 1345 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS]; 1346 } 1347 1348 int migrate_compress_level(void) 1349 { 1350 MigrationState *s; 1351 1352 s = migrate_get_current(); 1353 1354 return s->parameters.compress_level; 1355 } 1356 1357 int migrate_compress_threads(void) 1358 { 1359 MigrationState *s; 1360 1361 s = migrate_get_current(); 1362 1363 return s->parameters.compress_threads; 1364 } 1365 1366 int migrate_decompress_threads(void) 1367 { 1368 MigrationState *s; 1369 1370 s = migrate_get_current(); 1371 1372 return s->parameters.decompress_threads; 1373 } 1374 1375 bool migrate_use_events(void) 1376 { 1377 MigrationState *s; 1378 1379 s = migrate_get_current(); 1380 1381 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS]; 1382 } 1383 1384 int migrate_use_xbzrle(void) 1385 { 1386 MigrationState *s; 1387 1388 s = migrate_get_current(); 1389 1390 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; 1391 } 1392 1393 int64_t migrate_xbzrle_cache_size(void) 1394 { 1395 MigrationState *s; 1396 1397 s = migrate_get_current(); 1398 1399 return s->xbzrle_cache_size; 1400 } 1401 1402 /* migration thread support */ 1403 /* 1404 * Something bad happened to the RP stream, mark an error 1405 * The caller shall print or trace something to indicate why 1406 */ 1407 static void mark_source_rp_bad(MigrationState *s) 1408 { 1409 s->rp_state.error = true; 1410 } 1411 1412 static struct rp_cmd_args { 1413 ssize_t len; /* -1 = variable */ 1414 const char *name; 1415 } rp_cmd_args[] = { 1416 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, 1417 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, 1418 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, 1419 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, 1420 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, 1421 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, 1422 }; 1423 1424 /* 1425 * Process a request for pages received on the return path, 1426 * We're allowed to send more than requested (e.g. to round to our page size) 1427 * and we don't need to send pages that have already been sent. 1428 */ 1429 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, 1430 ram_addr_t start, size_t len) 1431 { 1432 long our_host_ps = getpagesize(); 1433 1434 trace_migrate_handle_rp_req_pages(rbname, start, len); 1435 1436 /* 1437 * Since we currently insist on matching page sizes, just sanity check 1438 * we're being asked for whole host pages. 1439 */ 1440 if (start & (our_host_ps-1) || 1441 (len & (our_host_ps-1))) { 1442 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT 1443 " len: %zd", __func__, start, len); 1444 mark_source_rp_bad(ms); 1445 return; 1446 } 1447 1448 if (ram_save_queue_pages(ms, rbname, start, len)) { 1449 mark_source_rp_bad(ms); 1450 } 1451 } 1452 1453 /* 1454 * Handles messages sent on the return path towards the source VM 1455 * 1456 */ 1457 static void *source_return_path_thread(void *opaque) 1458 { 1459 MigrationState *ms = opaque; 1460 QEMUFile *rp = ms->rp_state.from_dst_file; 1461 uint16_t header_len, header_type; 1462 uint8_t buf[512]; 1463 uint32_t tmp32, sibling_error; 1464 ram_addr_t start = 0; /* =0 to silence warning */ 1465 size_t len = 0, expected_len; 1466 int res; 1467 1468 trace_source_return_path_thread_entry(); 1469 while (!ms->rp_state.error && !qemu_file_get_error(rp) && 1470 migration_is_setup_or_active(ms->state)) { 1471 trace_source_return_path_thread_loop_top(); 1472 header_type = qemu_get_be16(rp); 1473 header_len = qemu_get_be16(rp); 1474 1475 if (header_type >= MIG_RP_MSG_MAX || 1476 header_type == MIG_RP_MSG_INVALID) { 1477 error_report("RP: Received invalid message 0x%04x length 0x%04x", 1478 header_type, header_len); 1479 mark_source_rp_bad(ms); 1480 goto out; 1481 } 1482 1483 if ((rp_cmd_args[header_type].len != -1 && 1484 header_len != rp_cmd_args[header_type].len) || 1485 header_len > sizeof(buf)) { 1486 error_report("RP: Received '%s' message (0x%04x) with" 1487 "incorrect length %d expecting %zu", 1488 rp_cmd_args[header_type].name, header_type, header_len, 1489 (size_t)rp_cmd_args[header_type].len); 1490 mark_source_rp_bad(ms); 1491 goto out; 1492 } 1493 1494 /* We know we've got a valid header by this point */ 1495 res = qemu_get_buffer(rp, buf, header_len); 1496 if (res != header_len) { 1497 error_report("RP: Failed reading data for message 0x%04x" 1498 " read %d expected %d", 1499 header_type, res, header_len); 1500 mark_source_rp_bad(ms); 1501 goto out; 1502 } 1503 1504 /* OK, we have the message and the data */ 1505 switch (header_type) { 1506 case MIG_RP_MSG_SHUT: 1507 sibling_error = ldl_be_p(buf); 1508 trace_source_return_path_thread_shut(sibling_error); 1509 if (sibling_error) { 1510 error_report("RP: Sibling indicated error %d", sibling_error); 1511 mark_source_rp_bad(ms); 1512 } 1513 /* 1514 * We'll let the main thread deal with closing the RP 1515 * we could do a shutdown(2) on it, but we're the only user 1516 * anyway, so there's nothing gained. 1517 */ 1518 goto out; 1519 1520 case MIG_RP_MSG_PONG: 1521 tmp32 = ldl_be_p(buf); 1522 trace_source_return_path_thread_pong(tmp32); 1523 break; 1524 1525 case MIG_RP_MSG_REQ_PAGES: 1526 start = ldq_be_p(buf); 1527 len = ldl_be_p(buf + 8); 1528 migrate_handle_rp_req_pages(ms, NULL, start, len); 1529 break; 1530 1531 case MIG_RP_MSG_REQ_PAGES_ID: 1532 expected_len = 12 + 1; /* header + termination */ 1533 1534 if (header_len >= expected_len) { 1535 start = ldq_be_p(buf); 1536 len = ldl_be_p(buf + 8); 1537 /* Now we expect an idstr */ 1538 tmp32 = buf[12]; /* Length of the following idstr */ 1539 buf[13 + tmp32] = '\0'; 1540 expected_len += tmp32; 1541 } 1542 if (header_len != expected_len) { 1543 error_report("RP: Req_Page_id with length %d expecting %zd", 1544 header_len, expected_len); 1545 mark_source_rp_bad(ms); 1546 goto out; 1547 } 1548 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); 1549 break; 1550 1551 default: 1552 break; 1553 } 1554 } 1555 if (qemu_file_get_error(rp)) { 1556 trace_source_return_path_thread_bad_end(); 1557 mark_source_rp_bad(ms); 1558 } 1559 1560 trace_source_return_path_thread_end(); 1561 out: 1562 ms->rp_state.from_dst_file = NULL; 1563 qemu_fclose(rp); 1564 return NULL; 1565 } 1566 1567 static int open_return_path_on_source(MigrationState *ms) 1568 { 1569 1570 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); 1571 if (!ms->rp_state.from_dst_file) { 1572 return -1; 1573 } 1574 1575 trace_open_return_path_on_source(); 1576 qemu_thread_create(&ms->rp_state.rp_thread, "return path", 1577 source_return_path_thread, ms, QEMU_THREAD_JOINABLE); 1578 1579 trace_open_return_path_on_source_continue(); 1580 1581 return 0; 1582 } 1583 1584 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */ 1585 static int await_return_path_close_on_source(MigrationState *ms) 1586 { 1587 /* 1588 * If this is a normal exit then the destination will send a SHUT and the 1589 * rp_thread will exit, however if there's an error we need to cause 1590 * it to exit. 1591 */ 1592 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) { 1593 /* 1594 * shutdown(2), if we have it, will cause it to unblock if it's stuck 1595 * waiting for the destination. 1596 */ 1597 qemu_file_shutdown(ms->rp_state.from_dst_file); 1598 mark_source_rp_bad(ms); 1599 } 1600 trace_await_return_path_close_on_source_joining(); 1601 qemu_thread_join(&ms->rp_state.rp_thread); 1602 trace_await_return_path_close_on_source_close(); 1603 return ms->rp_state.error; 1604 } 1605 1606 /* 1607 * Switch from normal iteration to postcopy 1608 * Returns non-0 on error 1609 */ 1610 static int postcopy_start(MigrationState *ms, bool *old_vm_running) 1611 { 1612 int ret; 1613 QIOChannelBuffer *bioc; 1614 QEMUFile *fb; 1615 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1616 bool restart_block = false; 1617 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE, 1618 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1619 1620 trace_postcopy_start(); 1621 qemu_mutex_lock_iothread(); 1622 trace_postcopy_start_set_run(); 1623 1624 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1625 *old_vm_running = runstate_is_running(); 1626 global_state_store(); 1627 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1628 if (ret < 0) { 1629 goto fail; 1630 } 1631 1632 ret = bdrv_inactivate_all(); 1633 if (ret < 0) { 1634 goto fail; 1635 } 1636 restart_block = true; 1637 1638 /* 1639 * Cause any non-postcopiable, but iterative devices to 1640 * send out their final data. 1641 */ 1642 qemu_savevm_state_complete_precopy(ms->to_dst_file, true); 1643 1644 /* 1645 * in Finish migrate and with the io-lock held everything should 1646 * be quiet, but we've potentially still got dirty pages and we 1647 * need to tell the destination to throw any pages it's already received 1648 * that are dirty 1649 */ 1650 if (ram_postcopy_send_discard_bitmap(ms)) { 1651 error_report("postcopy send discard bitmap failed"); 1652 goto fail; 1653 } 1654 1655 /* 1656 * send rest of state - note things that are doing postcopy 1657 * will notice we're in POSTCOPY_ACTIVE and not actually 1658 * wrap their state up here 1659 */ 1660 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); 1661 /* Ping just for debugging, helps line traces up */ 1662 qemu_savevm_send_ping(ms->to_dst_file, 2); 1663 1664 /* 1665 * While loading the device state we may trigger page transfer 1666 * requests and the fd must be free to process those, and thus 1667 * the destination must read the whole device state off the fd before 1668 * it starts processing it. Unfortunately the ad-hoc migration format 1669 * doesn't allow the destination to know the size to read without fully 1670 * parsing it through each devices load-state code (especially the open 1671 * coded devices that use get/put). 1672 * So we wrap the device state up in a package with a length at the start; 1673 * to do this we use a qemu_buf to hold the whole of the device state. 1674 */ 1675 bioc = qio_channel_buffer_new(4096); 1676 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer"); 1677 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 1678 object_unref(OBJECT(bioc)); 1679 1680 /* 1681 * Make sure the receiver can get incoming pages before we send the rest 1682 * of the state 1683 */ 1684 qemu_savevm_send_postcopy_listen(fb); 1685 1686 qemu_savevm_state_complete_precopy(fb, false); 1687 qemu_savevm_send_ping(fb, 3); 1688 1689 qemu_savevm_send_postcopy_run(fb); 1690 1691 /* <><> end of stuff going into the package */ 1692 1693 /* Last point of recovery; as soon as we send the package the destination 1694 * can open devices and potentially start running. 1695 * Lets just check again we've not got any errors. 1696 */ 1697 ret = qemu_file_get_error(ms->to_dst_file); 1698 if (ret) { 1699 error_report("postcopy_start: Migration stream errored (pre package)"); 1700 goto fail_closefb; 1701 } 1702 1703 restart_block = false; 1704 1705 /* Now send that blob */ 1706 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) { 1707 goto fail_closefb; 1708 } 1709 qemu_fclose(fb); 1710 1711 /* Send a notify to give a chance for anything that needs to happen 1712 * at the transition to postcopy and after the device state; in particular 1713 * spice needs to trigger a transition now 1714 */ 1715 ms->postcopy_after_devices = true; 1716 notifier_list_notify(&migration_state_notifiers, ms); 1717 1718 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop; 1719 1720 qemu_mutex_unlock_iothread(); 1721 1722 /* 1723 * Although this ping is just for debug, it could potentially be 1724 * used for getting a better measurement of downtime at the source. 1725 */ 1726 qemu_savevm_send_ping(ms->to_dst_file, 4); 1727 1728 if (migrate_release_ram()) { 1729 ram_postcopy_migrated_memory_release(ms); 1730 } 1731 1732 ret = qemu_file_get_error(ms->to_dst_file); 1733 if (ret) { 1734 error_report("postcopy_start: Migration stream errored"); 1735 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1736 MIGRATION_STATUS_FAILED); 1737 } 1738 1739 return ret; 1740 1741 fail_closefb: 1742 qemu_fclose(fb); 1743 fail: 1744 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1745 MIGRATION_STATUS_FAILED); 1746 if (restart_block) { 1747 /* A failure happened early enough that we know the destination hasn't 1748 * accessed block devices, so we're safe to recover. 1749 */ 1750 Error *local_err = NULL; 1751 1752 bdrv_invalidate_cache_all(&local_err); 1753 if (local_err) { 1754 error_report_err(local_err); 1755 } 1756 } 1757 qemu_mutex_unlock_iothread(); 1758 return -1; 1759 } 1760 1761 /** 1762 * migration_completion: Used by migration_thread when there's not much left. 1763 * The caller 'breaks' the loop when this returns. 1764 * 1765 * @s: Current migration state 1766 * @current_active_state: The migration state we expect to be in 1767 * @*old_vm_running: Pointer to old_vm_running flag 1768 * @*start_time: Pointer to time to update 1769 */ 1770 static void migration_completion(MigrationState *s, int current_active_state, 1771 bool *old_vm_running, 1772 int64_t *start_time) 1773 { 1774 int ret; 1775 1776 if (s->state == MIGRATION_STATUS_ACTIVE) { 1777 qemu_mutex_lock_iothread(); 1778 *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1779 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1780 *old_vm_running = runstate_is_running(); 1781 ret = global_state_store(); 1782 1783 if (!ret) { 1784 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1785 /* 1786 * Don't mark the image with BDRV_O_INACTIVE flag if 1787 * we will go into COLO stage later. 1788 */ 1789 if (ret >= 0 && !migrate_colo_enabled()) { 1790 ret = bdrv_inactivate_all(); 1791 } 1792 if (ret >= 0) { 1793 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX); 1794 qemu_savevm_state_complete_precopy(s->to_dst_file, false); 1795 s->block_inactive = true; 1796 } 1797 } 1798 qemu_mutex_unlock_iothread(); 1799 1800 if (ret < 0) { 1801 goto fail; 1802 } 1803 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1804 trace_migration_completion_postcopy_end(); 1805 1806 qemu_savevm_state_complete_postcopy(s->to_dst_file); 1807 trace_migration_completion_postcopy_end_after_complete(); 1808 } 1809 1810 /* 1811 * If rp was opened we must clean up the thread before 1812 * cleaning everything else up (since if there are no failures 1813 * it will wait for the destination to send it's status in 1814 * a SHUT command). 1815 * Postcopy opens rp if enabled (even if it's not avtivated) 1816 */ 1817 if (migrate_postcopy_ram()) { 1818 int rp_error; 1819 trace_migration_completion_postcopy_end_before_rp(); 1820 rp_error = await_return_path_close_on_source(s); 1821 trace_migration_completion_postcopy_end_after_rp(rp_error); 1822 if (rp_error) { 1823 goto fail_invalidate; 1824 } 1825 } 1826 1827 if (qemu_file_get_error(s->to_dst_file)) { 1828 trace_migration_completion_file_err(); 1829 goto fail_invalidate; 1830 } 1831 1832 if (!migrate_colo_enabled()) { 1833 migrate_set_state(&s->state, current_active_state, 1834 MIGRATION_STATUS_COMPLETED); 1835 } 1836 1837 return; 1838 1839 fail_invalidate: 1840 /* If not doing postcopy, vm_start() will be called: let's regain 1841 * control on images. 1842 */ 1843 if (s->state == MIGRATION_STATUS_ACTIVE) { 1844 Error *local_err = NULL; 1845 1846 qemu_mutex_lock_iothread(); 1847 bdrv_invalidate_cache_all(&local_err); 1848 if (local_err) { 1849 error_report_err(local_err); 1850 } else { 1851 s->block_inactive = false; 1852 } 1853 qemu_mutex_unlock_iothread(); 1854 } 1855 1856 fail: 1857 migrate_set_state(&s->state, current_active_state, 1858 MIGRATION_STATUS_FAILED); 1859 } 1860 1861 bool migrate_colo_enabled(void) 1862 { 1863 MigrationState *s = migrate_get_current(); 1864 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO]; 1865 } 1866 1867 /* 1868 * Master migration thread on the source VM. 1869 * It drives the migration and pumps the data down the outgoing channel. 1870 */ 1871 static void *migration_thread(void *opaque) 1872 { 1873 MigrationState *s = opaque; 1874 /* Used by the bandwidth calcs, updated later */ 1875 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1876 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); 1877 int64_t initial_bytes = 0; 1878 int64_t max_size = 0; 1879 int64_t start_time = initial_time; 1880 int64_t end_time; 1881 bool old_vm_running = false; 1882 bool entered_postcopy = false; 1883 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */ 1884 enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE; 1885 bool enable_colo = migrate_colo_enabled(); 1886 1887 rcu_register_thread(); 1888 1889 qemu_savevm_state_header(s->to_dst_file); 1890 1891 if (migrate_postcopy_ram()) { 1892 /* Now tell the dest that it should open its end so it can reply */ 1893 qemu_savevm_send_open_return_path(s->to_dst_file); 1894 1895 /* And do a ping that will make stuff easier to debug */ 1896 qemu_savevm_send_ping(s->to_dst_file, 1); 1897 1898 /* 1899 * Tell the destination that we *might* want to do postcopy later; 1900 * if the other end can't do postcopy it should fail now, nice and 1901 * early. 1902 */ 1903 qemu_savevm_send_postcopy_advise(s->to_dst_file); 1904 } 1905 1906 qemu_savevm_state_begin(s->to_dst_file, &s->params); 1907 1908 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; 1909 current_active_state = MIGRATION_STATUS_ACTIVE; 1910 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1911 MIGRATION_STATUS_ACTIVE); 1912 1913 trace_migration_thread_setup_complete(); 1914 1915 while (s->state == MIGRATION_STATUS_ACTIVE || 1916 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1917 int64_t current_time; 1918 uint64_t pending_size; 1919 1920 if (!qemu_file_rate_limit(s->to_dst_file)) { 1921 uint64_t pend_post, pend_nonpost; 1922 1923 qemu_savevm_state_pending(s->to_dst_file, max_size, &pend_nonpost, 1924 &pend_post); 1925 pending_size = pend_nonpost + pend_post; 1926 trace_migrate_pending(pending_size, max_size, 1927 pend_post, pend_nonpost); 1928 if (pending_size && pending_size >= max_size) { 1929 /* Still a significant amount to transfer */ 1930 1931 if (migrate_postcopy_ram() && 1932 s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE && 1933 pend_nonpost <= max_size && 1934 atomic_read(&s->start_postcopy)) { 1935 1936 if (!postcopy_start(s, &old_vm_running)) { 1937 current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE; 1938 entered_postcopy = true; 1939 } 1940 1941 continue; 1942 } 1943 /* Just another iteration step */ 1944 qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy); 1945 } else { 1946 trace_migration_thread_low_pending(pending_size); 1947 migration_completion(s, current_active_state, 1948 &old_vm_running, &start_time); 1949 break; 1950 } 1951 } 1952 1953 if (qemu_file_get_error(s->to_dst_file)) { 1954 migrate_set_state(&s->state, current_active_state, 1955 MIGRATION_STATUS_FAILED); 1956 trace_migration_thread_file_err(); 1957 break; 1958 } 1959 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1960 if (current_time >= initial_time + BUFFER_DELAY) { 1961 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file) - 1962 initial_bytes; 1963 uint64_t time_spent = current_time - initial_time; 1964 double bandwidth = (double)transferred_bytes / time_spent; 1965 max_size = bandwidth * s->parameters.downtime_limit; 1966 1967 s->mbps = (((double) transferred_bytes * 8.0) / 1968 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; 1969 1970 trace_migrate_transferred(transferred_bytes, time_spent, 1971 bandwidth, max_size); 1972 /* if we haven't sent anything, we don't want to recalculate 1973 10000 is a small enough number for our purposes */ 1974 if (s->dirty_bytes_rate && transferred_bytes > 10000) { 1975 s->expected_downtime = s->dirty_bytes_rate / bandwidth; 1976 } 1977 1978 qemu_file_reset_rate_limit(s->to_dst_file); 1979 initial_time = current_time; 1980 initial_bytes = qemu_ftell(s->to_dst_file); 1981 } 1982 if (qemu_file_rate_limit(s->to_dst_file)) { 1983 /* usleep expects microseconds */ 1984 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); 1985 } 1986 } 1987 1988 trace_migration_thread_after_loop(); 1989 /* If we enabled cpu throttling for auto-converge, turn it off. */ 1990 cpu_throttle_stop(); 1991 end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1992 1993 qemu_mutex_lock_iothread(); 1994 /* 1995 * The resource has been allocated by migration will be reused in COLO 1996 * process, so don't release them. 1997 */ 1998 if (!enable_colo) { 1999 qemu_savevm_state_cleanup(); 2000 } 2001 if (s->state == MIGRATION_STATUS_COMPLETED) { 2002 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file); 2003 s->total_time = end_time - s->total_time; 2004 if (!entered_postcopy) { 2005 s->downtime = end_time - start_time; 2006 } 2007 if (s->total_time) { 2008 s->mbps = (((double) transferred_bytes * 8.0) / 2009 ((double) s->total_time)) / 1000; 2010 } 2011 runstate_set(RUN_STATE_POSTMIGRATE); 2012 } else { 2013 if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) { 2014 migrate_start_colo_process(s); 2015 qemu_savevm_state_cleanup(); 2016 /* 2017 * Fixme: we will run VM in COLO no matter its old running state. 2018 * After exited COLO, we will keep running. 2019 */ 2020 old_vm_running = true; 2021 } 2022 if (old_vm_running && !entered_postcopy) { 2023 vm_start(); 2024 } else { 2025 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) { 2026 runstate_set(RUN_STATE_POSTMIGRATE); 2027 } 2028 } 2029 } 2030 qemu_bh_schedule(s->cleanup_bh); 2031 qemu_mutex_unlock_iothread(); 2032 2033 rcu_unregister_thread(); 2034 return NULL; 2035 } 2036 2037 void migrate_fd_connect(MigrationState *s) 2038 { 2039 s->expected_downtime = s->parameters.downtime_limit; 2040 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); 2041 2042 qemu_file_set_blocking(s->to_dst_file, true); 2043 qemu_file_set_rate_limit(s->to_dst_file, 2044 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 2045 2046 /* Notify before starting migration thread */ 2047 notifier_list_notify(&migration_state_notifiers, s); 2048 2049 /* 2050 * Open the return path; currently for postcopy but other things might 2051 * also want it. 2052 */ 2053 if (migrate_postcopy_ram()) { 2054 if (open_return_path_on_source(s)) { 2055 error_report("Unable to open return-path for postcopy"); 2056 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 2057 MIGRATION_STATUS_FAILED); 2058 migrate_fd_cleanup(s); 2059 return; 2060 } 2061 } 2062 2063 migrate_compress_threads_create(); 2064 qemu_thread_create(&s->thread, "live_migration", migration_thread, s, 2065 QEMU_THREAD_JOINABLE); 2066 s->migration_thread_running = true; 2067 } 2068 2069 PostcopyState postcopy_state_get(void) 2070 { 2071 return atomic_mb_read(&incoming_postcopy_state); 2072 } 2073 2074 /* Set the state and return the old state */ 2075 PostcopyState postcopy_state_set(PostcopyState new_state) 2076 { 2077 return atomic_xchg(&incoming_postcopy_state, new_state); 2078 } 2079 2080