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 "migration/blocker.h" 20 #include "exec.h" 21 #include "fd.h" 22 #include "socket.h" 23 #include "rdma.h" 24 #include "ram.h" 25 #include "migration/global_state.h" 26 #include "migration/misc.h" 27 #include "migration.h" 28 #include "savevm.h" 29 #include "qemu-file-channel.h" 30 #include "qemu-file.h" 31 #include "migration/vmstate.h" 32 #include "block/block.h" 33 #include "qapi/error.h" 34 #include "qapi/qapi-commands-migration.h" 35 #include "qapi/qapi-events-migration.h" 36 #include "qapi/qmp/qerror.h" 37 #include "qapi/qmp/qnull.h" 38 #include "qemu/rcu.h" 39 #include "block.h" 40 #include "postcopy-ram.h" 41 #include "qemu/thread.h" 42 #include "trace.h" 43 #include "exec/target_page.h" 44 #include "io/channel-buffer.h" 45 #include "migration/colo.h" 46 #include "hw/boards.h" 47 #include "monitor/monitor.h" 48 49 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ 50 51 /* Amount of time to allocate to each "chunk" of bandwidth-throttled 52 * data. */ 53 #define BUFFER_DELAY 100 54 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) 55 56 /* Time in milliseconds we are allowed to stop the source, 57 * for sending the last part */ 58 #define DEFAULT_MIGRATE_SET_DOWNTIME 300 59 60 /* Maximum migrate downtime set to 2000 seconds */ 61 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000 62 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000) 63 64 /* Default compression thread count */ 65 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8 66 /* Default decompression thread count, usually decompression is at 67 * least 4 times as fast as compression.*/ 68 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2 69 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */ 70 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1 71 /* Define default autoconverge cpu throttle migration parameters */ 72 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20 73 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10 74 75 /* Migration XBZRLE default cache size */ 76 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024) 77 78 /* The delay time (in ms) between two COLO checkpoints 79 * Note: Please change this default value to 10000 when we support hybrid mode. 80 */ 81 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200 82 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2 83 #define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16 84 85 static NotifierList migration_state_notifiers = 86 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); 87 88 static bool deferred_incoming; 89 90 /* Messages sent on the return path from destination to source */ 91 enum mig_rp_message_type { 92 MIG_RP_MSG_INVALID = 0, /* Must be 0 */ 93 MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */ 94 MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */ 95 96 MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */ 97 MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */ 98 99 MIG_RP_MSG_MAX 100 }; 101 102 /* When we add fault tolerance, we could have several 103 migrations at once. For now we don't need to add 104 dynamic creation of migration */ 105 106 static MigrationState *current_migration; 107 108 static bool migration_object_check(MigrationState *ms, Error **errp); 109 static int migration_maybe_pause(MigrationState *s, 110 int *current_active_state, 111 int new_state); 112 113 void migration_object_init(void) 114 { 115 MachineState *ms = MACHINE(qdev_get_machine()); 116 Error *err = NULL; 117 118 /* This can only be called once. */ 119 assert(!current_migration); 120 current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION)); 121 122 if (!migration_object_check(current_migration, &err)) { 123 error_report_err(err); 124 exit(1); 125 } 126 127 /* 128 * We cannot really do this in migration_instance_init() since at 129 * that time global properties are not yet applied, then this 130 * value will be definitely replaced by something else. 131 */ 132 if (ms->enforce_config_section) { 133 current_migration->send_configuration = true; 134 } 135 } 136 137 void migration_object_finalize(void) 138 { 139 object_unref(OBJECT(current_migration)); 140 } 141 142 /* For outgoing */ 143 MigrationState *migrate_get_current(void) 144 { 145 /* This can only be called after the object created. */ 146 assert(current_migration); 147 return current_migration; 148 } 149 150 MigrationIncomingState *migration_incoming_get_current(void) 151 { 152 static bool once; 153 static MigrationIncomingState mis_current; 154 155 if (!once) { 156 mis_current.state = MIGRATION_STATUS_NONE; 157 memset(&mis_current, 0, sizeof(MigrationIncomingState)); 158 mis_current.postcopy_remote_fds = g_array_new(FALSE, TRUE, 159 sizeof(struct PostCopyFD)); 160 qemu_mutex_init(&mis_current.rp_mutex); 161 qemu_event_init(&mis_current.main_thread_load_event, false); 162 163 init_dirty_bitmap_incoming_migration(); 164 165 once = true; 166 } 167 return &mis_current; 168 } 169 170 void migration_incoming_state_destroy(void) 171 { 172 struct MigrationIncomingState *mis = migration_incoming_get_current(); 173 174 if (mis->to_src_file) { 175 /* Tell source that we are done */ 176 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0); 177 qemu_fclose(mis->to_src_file); 178 mis->to_src_file = NULL; 179 } 180 181 if (mis->from_src_file) { 182 qemu_fclose(mis->from_src_file); 183 mis->from_src_file = NULL; 184 } 185 if (mis->postcopy_remote_fds) { 186 g_array_free(mis->postcopy_remote_fds, TRUE); 187 mis->postcopy_remote_fds = NULL; 188 } 189 190 qemu_event_reset(&mis->main_thread_load_event); 191 } 192 193 static void migrate_generate_event(int new_state) 194 { 195 if (migrate_use_events()) { 196 qapi_event_send_migration(new_state, &error_abort); 197 } 198 } 199 200 /* 201 * Called on -incoming with a defer: uri. 202 * The migration can be started later after any parameters have been 203 * changed. 204 */ 205 static void deferred_incoming_migration(Error **errp) 206 { 207 if (deferred_incoming) { 208 error_setg(errp, "Incoming migration already deferred"); 209 } 210 deferred_incoming = true; 211 } 212 213 /* 214 * Send a message on the return channel back to the source 215 * of the migration. 216 */ 217 static int migrate_send_rp_message(MigrationIncomingState *mis, 218 enum mig_rp_message_type message_type, 219 uint16_t len, void *data) 220 { 221 int ret = 0; 222 223 trace_migrate_send_rp_message((int)message_type, len); 224 qemu_mutex_lock(&mis->rp_mutex); 225 226 /* 227 * It's possible that the file handle got lost due to network 228 * failures. 229 */ 230 if (!mis->to_src_file) { 231 ret = -EIO; 232 goto error; 233 } 234 235 qemu_put_be16(mis->to_src_file, (unsigned int)message_type); 236 qemu_put_be16(mis->to_src_file, len); 237 qemu_put_buffer(mis->to_src_file, data, len); 238 qemu_fflush(mis->to_src_file); 239 240 /* It's possible that qemu file got error during sending */ 241 ret = qemu_file_get_error(mis->to_src_file); 242 243 error: 244 qemu_mutex_unlock(&mis->rp_mutex); 245 return ret; 246 } 247 248 /* Request a range of pages from the source VM at the given 249 * start address. 250 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same 251 * as the last request (a name must have been given previously) 252 * Start: Address offset within the RB 253 * Len: Length in bytes required - must be a multiple of pagesize 254 */ 255 int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, 256 ram_addr_t start, size_t len) 257 { 258 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */ 259 size_t msglen = 12; /* start + len */ 260 enum mig_rp_message_type msg_type; 261 262 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); 263 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); 264 265 if (rbname) { 266 int rbname_len = strlen(rbname); 267 assert(rbname_len < 256); 268 269 bufc[msglen++] = rbname_len; 270 memcpy(bufc + msglen, rbname, rbname_len); 271 msglen += rbname_len; 272 msg_type = MIG_RP_MSG_REQ_PAGES_ID; 273 } else { 274 msg_type = MIG_RP_MSG_REQ_PAGES; 275 } 276 277 return migrate_send_rp_message(mis, msg_type, msglen, bufc); 278 } 279 280 void qemu_start_incoming_migration(const char *uri, Error **errp) 281 { 282 const char *p; 283 284 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort); 285 if (!strcmp(uri, "defer")) { 286 deferred_incoming_migration(errp); 287 } else if (strstart(uri, "tcp:", &p)) { 288 tcp_start_incoming_migration(p, errp); 289 #ifdef CONFIG_RDMA 290 } else if (strstart(uri, "rdma:", &p)) { 291 rdma_start_incoming_migration(p, errp); 292 #endif 293 } else if (strstart(uri, "exec:", &p)) { 294 exec_start_incoming_migration(p, errp); 295 } else if (strstart(uri, "unix:", &p)) { 296 unix_start_incoming_migration(p, errp); 297 } else if (strstart(uri, "fd:", &p)) { 298 fd_start_incoming_migration(p, errp); 299 } else { 300 error_setg(errp, "unknown migration protocol: %s", uri); 301 } 302 } 303 304 static void process_incoming_migration_bh(void *opaque) 305 { 306 Error *local_err = NULL; 307 MigrationIncomingState *mis = opaque; 308 309 /* Make sure all file formats flush their mutable metadata. 310 * If we get an error here, just don't restart the VM yet. */ 311 bdrv_invalidate_cache_all(&local_err); 312 if (local_err) { 313 error_report_err(local_err); 314 local_err = NULL; 315 autostart = false; 316 } 317 318 /* 319 * This must happen after all error conditions are dealt with and 320 * we're sure the VM is going to be running on this host. 321 */ 322 qemu_announce_self(); 323 324 if (multifd_load_cleanup(&local_err) != 0) { 325 error_report_err(local_err); 326 autostart = false; 327 } 328 /* If global state section was not received or we are in running 329 state, we need to obey autostart. Any other state is set with 330 runstate_set. */ 331 332 dirty_bitmap_mig_before_vm_start(); 333 334 if (!global_state_received() || 335 global_state_get_runstate() == RUN_STATE_RUNNING) { 336 if (autostart) { 337 vm_start(); 338 } else { 339 runstate_set(RUN_STATE_PAUSED); 340 } 341 } else { 342 runstate_set(global_state_get_runstate()); 343 } 344 /* 345 * This must happen after any state changes since as soon as an external 346 * observer sees this event they might start to prod at the VM assuming 347 * it's ready to use. 348 */ 349 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 350 MIGRATION_STATUS_COMPLETED); 351 qemu_bh_delete(mis->bh); 352 migration_incoming_state_destroy(); 353 } 354 355 static void process_incoming_migration_co(void *opaque) 356 { 357 MigrationIncomingState *mis = migration_incoming_get_current(); 358 PostcopyState ps; 359 int ret; 360 361 assert(mis->from_src_file); 362 mis->largest_page_size = qemu_ram_pagesize_largest(); 363 postcopy_state_set(POSTCOPY_INCOMING_NONE); 364 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE, 365 MIGRATION_STATUS_ACTIVE); 366 ret = qemu_loadvm_state(mis->from_src_file); 367 368 ps = postcopy_state_get(); 369 trace_process_incoming_migration_co_end(ret, ps); 370 if (ps != POSTCOPY_INCOMING_NONE) { 371 if (ps == POSTCOPY_INCOMING_ADVISE) { 372 /* 373 * Where a migration had postcopy enabled (and thus went to advise) 374 * but managed to complete within the precopy period, we can use 375 * the normal exit. 376 */ 377 postcopy_ram_incoming_cleanup(mis); 378 } else if (ret >= 0) { 379 /* 380 * Postcopy was started, cleanup should happen at the end of the 381 * postcopy thread. 382 */ 383 trace_process_incoming_migration_co_postcopy_end_main(); 384 return; 385 } 386 /* Else if something went wrong then just fall out of the normal exit */ 387 } 388 389 /* we get COLO info, and know if we are in COLO mode */ 390 if (!ret && migration_incoming_enable_colo()) { 391 mis->migration_incoming_co = qemu_coroutine_self(); 392 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming", 393 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE); 394 mis->have_colo_incoming_thread = true; 395 qemu_coroutine_yield(); 396 397 /* Wait checkpoint incoming thread exit before free resource */ 398 qemu_thread_join(&mis->colo_incoming_thread); 399 } 400 401 if (ret < 0) { 402 Error *local_err = NULL; 403 404 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 405 MIGRATION_STATUS_FAILED); 406 error_report("load of migration failed: %s", strerror(-ret)); 407 qemu_fclose(mis->from_src_file); 408 if (multifd_load_cleanup(&local_err) != 0) { 409 error_report_err(local_err); 410 } 411 exit(EXIT_FAILURE); 412 } 413 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); 414 qemu_bh_schedule(mis->bh); 415 } 416 417 static void migration_incoming_setup(QEMUFile *f) 418 { 419 MigrationIncomingState *mis = migration_incoming_get_current(); 420 421 if (multifd_load_setup() != 0) { 422 /* We haven't been able to create multifd threads 423 nothing better to do */ 424 exit(EXIT_FAILURE); 425 } 426 427 if (!mis->from_src_file) { 428 mis->from_src_file = f; 429 } 430 qemu_file_set_blocking(f, false); 431 } 432 433 static void migration_incoming_process(void) 434 { 435 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL); 436 qemu_coroutine_enter(co); 437 } 438 439 void migration_fd_process_incoming(QEMUFile *f) 440 { 441 migration_incoming_setup(f); 442 migration_incoming_process(); 443 } 444 445 void migration_ioc_process_incoming(QIOChannel *ioc) 446 { 447 MigrationIncomingState *mis = migration_incoming_get_current(); 448 449 if (!mis->from_src_file) { 450 QEMUFile *f = qemu_fopen_channel_input(ioc); 451 migration_fd_process_incoming(f); 452 } 453 /* We still only have a single channel. Nothing to do here yet */ 454 } 455 456 /** 457 * @migration_has_all_channels: We have received all channels that we need 458 * 459 * Returns true when we have got connections to all the channels that 460 * we need for migration. 461 */ 462 bool migration_has_all_channels(void) 463 { 464 return true; 465 } 466 467 /* 468 * Send a 'SHUT' message on the return channel with the given value 469 * to indicate that we've finished with the RP. Non-0 value indicates 470 * error. 471 */ 472 void migrate_send_rp_shut(MigrationIncomingState *mis, 473 uint32_t value) 474 { 475 uint32_t buf; 476 477 buf = cpu_to_be32(value); 478 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); 479 } 480 481 /* 482 * Send a 'PONG' message on the return channel with the given value 483 * (normally in response to a 'PING') 484 */ 485 void migrate_send_rp_pong(MigrationIncomingState *mis, 486 uint32_t value) 487 { 488 uint32_t buf; 489 490 buf = cpu_to_be32(value); 491 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); 492 } 493 494 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) 495 { 496 MigrationCapabilityStatusList *head = NULL; 497 MigrationCapabilityStatusList *caps; 498 MigrationState *s = migrate_get_current(); 499 int i; 500 501 caps = NULL; /* silence compiler warning */ 502 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 503 #ifndef CONFIG_LIVE_BLOCK_MIGRATION 504 if (i == MIGRATION_CAPABILITY_BLOCK) { 505 continue; 506 } 507 #endif 508 if (head == NULL) { 509 head = g_malloc0(sizeof(*caps)); 510 caps = head; 511 } else { 512 caps->next = g_malloc0(sizeof(*caps)); 513 caps = caps->next; 514 } 515 caps->value = 516 g_malloc(sizeof(*caps->value)); 517 caps->value->capability = i; 518 caps->value->state = s->enabled_capabilities[i]; 519 } 520 521 return head; 522 } 523 524 MigrationParameters *qmp_query_migrate_parameters(Error **errp) 525 { 526 MigrationParameters *params; 527 MigrationState *s = migrate_get_current(); 528 529 /* TODO use QAPI_CLONE() instead of duplicating it inline */ 530 params = g_malloc0(sizeof(*params)); 531 params->has_compress_level = true; 532 params->compress_level = s->parameters.compress_level; 533 params->has_compress_threads = true; 534 params->compress_threads = s->parameters.compress_threads; 535 params->has_decompress_threads = true; 536 params->decompress_threads = s->parameters.decompress_threads; 537 params->has_cpu_throttle_initial = true; 538 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; 539 params->has_cpu_throttle_increment = true; 540 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; 541 params->has_tls_creds = true; 542 params->tls_creds = g_strdup(s->parameters.tls_creds); 543 params->has_tls_hostname = true; 544 params->tls_hostname = g_strdup(s->parameters.tls_hostname); 545 params->has_max_bandwidth = true; 546 params->max_bandwidth = s->parameters.max_bandwidth; 547 params->has_downtime_limit = true; 548 params->downtime_limit = s->parameters.downtime_limit; 549 params->has_x_checkpoint_delay = true; 550 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay; 551 params->has_block_incremental = true; 552 params->block_incremental = s->parameters.block_incremental; 553 params->has_x_multifd_channels = true; 554 params->x_multifd_channels = s->parameters.x_multifd_channels; 555 params->has_x_multifd_page_count = true; 556 params->x_multifd_page_count = s->parameters.x_multifd_page_count; 557 params->has_xbzrle_cache_size = true; 558 params->xbzrle_cache_size = s->parameters.xbzrle_cache_size; 559 560 return params; 561 } 562 563 /* 564 * Return true if we're already in the middle of a migration 565 * (i.e. any of the active or setup states) 566 */ 567 static bool migration_is_setup_or_active(int state) 568 { 569 switch (state) { 570 case MIGRATION_STATUS_ACTIVE: 571 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 572 case MIGRATION_STATUS_SETUP: 573 case MIGRATION_STATUS_PRE_SWITCHOVER: 574 case MIGRATION_STATUS_DEVICE: 575 return true; 576 577 default: 578 return false; 579 580 } 581 } 582 583 static void populate_ram_info(MigrationInfo *info, MigrationState *s) 584 { 585 info->has_ram = true; 586 info->ram = g_malloc0(sizeof(*info->ram)); 587 info->ram->transferred = ram_counters.transferred; 588 info->ram->total = ram_bytes_total(); 589 info->ram->duplicate = ram_counters.duplicate; 590 /* legacy value. It is not used anymore */ 591 info->ram->skipped = 0; 592 info->ram->normal = ram_counters.normal; 593 info->ram->normal_bytes = ram_counters.normal * 594 qemu_target_page_size(); 595 info->ram->mbps = s->mbps; 596 info->ram->dirty_sync_count = ram_counters.dirty_sync_count; 597 info->ram->postcopy_requests = ram_counters.postcopy_requests; 598 info->ram->page_size = qemu_target_page_size(); 599 600 if (migrate_use_xbzrle()) { 601 info->has_xbzrle_cache = true; 602 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); 603 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); 604 info->xbzrle_cache->bytes = xbzrle_counters.bytes; 605 info->xbzrle_cache->pages = xbzrle_counters.pages; 606 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss; 607 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate; 608 info->xbzrle_cache->overflow = xbzrle_counters.overflow; 609 } 610 611 if (cpu_throttle_active()) { 612 info->has_cpu_throttle_percentage = true; 613 info->cpu_throttle_percentage = cpu_throttle_get_percentage(); 614 } 615 616 if (s->state != MIGRATION_STATUS_COMPLETED) { 617 info->ram->remaining = ram_bytes_remaining(); 618 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate; 619 } 620 } 621 622 static void populate_disk_info(MigrationInfo *info) 623 { 624 if (blk_mig_active()) { 625 info->has_disk = true; 626 info->disk = g_malloc0(sizeof(*info->disk)); 627 info->disk->transferred = blk_mig_bytes_transferred(); 628 info->disk->remaining = blk_mig_bytes_remaining(); 629 info->disk->total = blk_mig_bytes_total(); 630 } 631 } 632 633 MigrationInfo *qmp_query_migrate(Error **errp) 634 { 635 MigrationInfo *info = g_malloc0(sizeof(*info)); 636 MigrationState *s = migrate_get_current(); 637 638 switch (s->state) { 639 case MIGRATION_STATUS_NONE: 640 /* no migration has happened ever */ 641 break; 642 case MIGRATION_STATUS_SETUP: 643 info->has_status = true; 644 info->has_total_time = false; 645 break; 646 case MIGRATION_STATUS_ACTIVE: 647 case MIGRATION_STATUS_CANCELLING: 648 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 649 case MIGRATION_STATUS_PRE_SWITCHOVER: 650 case MIGRATION_STATUS_DEVICE: 651 /* TODO add some postcopy stats */ 652 info->has_status = true; 653 info->has_total_time = true; 654 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 655 - s->start_time; 656 info->has_expected_downtime = true; 657 info->expected_downtime = s->expected_downtime; 658 info->has_setup_time = true; 659 info->setup_time = s->setup_time; 660 661 populate_ram_info(info, s); 662 populate_disk_info(info); 663 break; 664 case MIGRATION_STATUS_COLO: 665 info->has_status = true; 666 /* TODO: display COLO specific information (checkpoint info etc.) */ 667 break; 668 case MIGRATION_STATUS_COMPLETED: 669 info->has_status = true; 670 info->has_total_time = true; 671 info->total_time = s->total_time; 672 info->has_downtime = true; 673 info->downtime = s->downtime; 674 info->has_setup_time = true; 675 info->setup_time = s->setup_time; 676 677 populate_ram_info(info, s); 678 break; 679 case MIGRATION_STATUS_FAILED: 680 info->has_status = true; 681 if (s->error) { 682 info->has_error_desc = true; 683 info->error_desc = g_strdup(error_get_pretty(s->error)); 684 } 685 break; 686 case MIGRATION_STATUS_CANCELLED: 687 info->has_status = true; 688 break; 689 } 690 info->status = s->state; 691 692 return info; 693 } 694 695 /** 696 * @migration_caps_check - check capability validity 697 * 698 * @cap_list: old capability list, array of bool 699 * @params: new capabilities to be applied soon 700 * @errp: set *errp if the check failed, with reason 701 * 702 * Returns true if check passed, otherwise false. 703 */ 704 static bool migrate_caps_check(bool *cap_list, 705 MigrationCapabilityStatusList *params, 706 Error **errp) 707 { 708 MigrationCapabilityStatusList *cap; 709 bool old_postcopy_cap; 710 MigrationIncomingState *mis = migration_incoming_get_current(); 711 712 old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 713 714 for (cap = params; cap; cap = cap->next) { 715 cap_list[cap->value->capability] = cap->value->state; 716 } 717 718 #ifndef CONFIG_LIVE_BLOCK_MIGRATION 719 if (cap_list[MIGRATION_CAPABILITY_BLOCK]) { 720 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) " 721 "block migration"); 722 error_append_hint(errp, "Use drive_mirror+NBD instead.\n"); 723 return false; 724 } 725 #endif 726 727 if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) { 728 if (cap_list[MIGRATION_CAPABILITY_COMPRESS]) { 729 /* The decompression threads asynchronously write into RAM 730 * rather than use the atomic copies needed to avoid 731 * userfaulting. It should be possible to fix the decompression 732 * threads for compatibility in future. 733 */ 734 error_setg(errp, "Postcopy is not currently compatible " 735 "with compression"); 736 return false; 737 } 738 739 /* This check is reasonably expensive, so only when it's being 740 * set the first time, also it's only the destination that needs 741 * special support. 742 */ 743 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) && 744 !postcopy_ram_supported_by_host(mis)) { 745 /* postcopy_ram_supported_by_host will have emitted a more 746 * detailed message 747 */ 748 error_setg(errp, "Postcopy is not supported"); 749 return false; 750 } 751 } 752 753 return true; 754 } 755 756 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 757 Error **errp) 758 { 759 MigrationState *s = migrate_get_current(); 760 MigrationCapabilityStatusList *cap; 761 bool cap_list[MIGRATION_CAPABILITY__MAX]; 762 763 if (migration_is_setup_or_active(s->state)) { 764 error_setg(errp, QERR_MIGRATION_ACTIVE); 765 return; 766 } 767 768 memcpy(cap_list, s->enabled_capabilities, sizeof(cap_list)); 769 if (!migrate_caps_check(cap_list, params, errp)) { 770 return; 771 } 772 773 for (cap = params; cap; cap = cap->next) { 774 s->enabled_capabilities[cap->value->capability] = cap->value->state; 775 } 776 } 777 778 /* 779 * Check whether the parameters are valid. Error will be put into errp 780 * (if provided). Return true if valid, otherwise false. 781 */ 782 static bool migrate_params_check(MigrationParameters *params, Error **errp) 783 { 784 if (params->has_compress_level && 785 (params->compress_level > 9)) { 786 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level", 787 "is invalid, it should be in the range of 0 to 9"); 788 return false; 789 } 790 791 if (params->has_compress_threads && (params->compress_threads < 1)) { 792 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 793 "compress_threads", 794 "is invalid, it should be in the range of 1 to 255"); 795 return false; 796 } 797 798 if (params->has_decompress_threads && (params->decompress_threads < 1)) { 799 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 800 "decompress_threads", 801 "is invalid, it should be in the range of 1 to 255"); 802 return false; 803 } 804 805 if (params->has_cpu_throttle_initial && 806 (params->cpu_throttle_initial < 1 || 807 params->cpu_throttle_initial > 99)) { 808 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 809 "cpu_throttle_initial", 810 "an integer in the range of 1 to 99"); 811 return false; 812 } 813 814 if (params->has_cpu_throttle_increment && 815 (params->cpu_throttle_increment < 1 || 816 params->cpu_throttle_increment > 99)) { 817 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 818 "cpu_throttle_increment", 819 "an integer in the range of 1 to 99"); 820 return false; 821 } 822 823 if (params->has_max_bandwidth && (params->max_bandwidth > SIZE_MAX)) { 824 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the" 825 " range of 0 to %zu bytes/second", SIZE_MAX); 826 return false; 827 } 828 829 if (params->has_downtime_limit && 830 (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) { 831 error_setg(errp, "Parameter 'downtime_limit' expects an integer in " 832 "the range of 0 to %d milliseconds", 833 MAX_MIGRATE_DOWNTIME); 834 return false; 835 } 836 837 /* x_checkpoint_delay is now always positive */ 838 839 if (params->has_x_multifd_channels && (params->x_multifd_channels < 1)) { 840 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 841 "multifd_channels", 842 "is invalid, it should be in the range of 1 to 255"); 843 return false; 844 } 845 if (params->has_x_multifd_page_count && 846 (params->x_multifd_page_count < 1 || 847 params->x_multifd_page_count > 10000)) { 848 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 849 "multifd_page_count", 850 "is invalid, it should be in the range of 1 to 10000"); 851 return false; 852 } 853 854 if (params->has_xbzrle_cache_size && 855 (params->xbzrle_cache_size < qemu_target_page_size() || 856 !is_power_of_2(params->xbzrle_cache_size))) { 857 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 858 "xbzrle_cache_size", 859 "is invalid, it should be bigger than target page size" 860 " and a power of two"); 861 return false; 862 } 863 864 return true; 865 } 866 867 static void migrate_params_test_apply(MigrateSetParameters *params, 868 MigrationParameters *dest) 869 { 870 *dest = migrate_get_current()->parameters; 871 872 /* TODO use QAPI_CLONE() instead of duplicating it inline */ 873 874 if (params->has_compress_level) { 875 dest->compress_level = params->compress_level; 876 } 877 878 if (params->has_compress_threads) { 879 dest->compress_threads = params->compress_threads; 880 } 881 882 if (params->has_decompress_threads) { 883 dest->decompress_threads = params->decompress_threads; 884 } 885 886 if (params->has_cpu_throttle_initial) { 887 dest->cpu_throttle_initial = params->cpu_throttle_initial; 888 } 889 890 if (params->has_cpu_throttle_increment) { 891 dest->cpu_throttle_increment = params->cpu_throttle_increment; 892 } 893 894 if (params->has_tls_creds) { 895 assert(params->tls_creds->type == QTYPE_QSTRING); 896 dest->tls_creds = g_strdup(params->tls_creds->u.s); 897 } 898 899 if (params->has_tls_hostname) { 900 assert(params->tls_hostname->type == QTYPE_QSTRING); 901 dest->tls_hostname = g_strdup(params->tls_hostname->u.s); 902 } 903 904 if (params->has_max_bandwidth) { 905 dest->max_bandwidth = params->max_bandwidth; 906 } 907 908 if (params->has_downtime_limit) { 909 dest->downtime_limit = params->downtime_limit; 910 } 911 912 if (params->has_x_checkpoint_delay) { 913 dest->x_checkpoint_delay = params->x_checkpoint_delay; 914 } 915 916 if (params->has_block_incremental) { 917 dest->block_incremental = params->block_incremental; 918 } 919 if (params->has_x_multifd_channels) { 920 dest->x_multifd_channels = params->x_multifd_channels; 921 } 922 if (params->has_x_multifd_page_count) { 923 dest->x_multifd_page_count = params->x_multifd_page_count; 924 } 925 if (params->has_xbzrle_cache_size) { 926 dest->xbzrle_cache_size = params->xbzrle_cache_size; 927 } 928 } 929 930 static void migrate_params_apply(MigrateSetParameters *params, Error **errp) 931 { 932 MigrationState *s = migrate_get_current(); 933 934 /* TODO use QAPI_CLONE() instead of duplicating it inline */ 935 936 if (params->has_compress_level) { 937 s->parameters.compress_level = params->compress_level; 938 } 939 940 if (params->has_compress_threads) { 941 s->parameters.compress_threads = params->compress_threads; 942 } 943 944 if (params->has_decompress_threads) { 945 s->parameters.decompress_threads = params->decompress_threads; 946 } 947 948 if (params->has_cpu_throttle_initial) { 949 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial; 950 } 951 952 if (params->has_cpu_throttle_increment) { 953 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; 954 } 955 956 if (params->has_tls_creds) { 957 g_free(s->parameters.tls_creds); 958 assert(params->tls_creds->type == QTYPE_QSTRING); 959 s->parameters.tls_creds = g_strdup(params->tls_creds->u.s); 960 } 961 962 if (params->has_tls_hostname) { 963 g_free(s->parameters.tls_hostname); 964 assert(params->tls_hostname->type == QTYPE_QSTRING); 965 s->parameters.tls_hostname = g_strdup(params->tls_hostname->u.s); 966 } 967 968 if (params->has_max_bandwidth) { 969 s->parameters.max_bandwidth = params->max_bandwidth; 970 if (s->to_dst_file) { 971 qemu_file_set_rate_limit(s->to_dst_file, 972 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 973 } 974 } 975 976 if (params->has_downtime_limit) { 977 s->parameters.downtime_limit = params->downtime_limit; 978 } 979 980 if (params->has_x_checkpoint_delay) { 981 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay; 982 if (migration_in_colo_state()) { 983 colo_checkpoint_notify(s); 984 } 985 } 986 987 if (params->has_block_incremental) { 988 s->parameters.block_incremental = params->block_incremental; 989 } 990 if (params->has_x_multifd_channels) { 991 s->parameters.x_multifd_channels = params->x_multifd_channels; 992 } 993 if (params->has_x_multifd_page_count) { 994 s->parameters.x_multifd_page_count = params->x_multifd_page_count; 995 } 996 if (params->has_xbzrle_cache_size) { 997 s->parameters.xbzrle_cache_size = params->xbzrle_cache_size; 998 xbzrle_cache_resize(params->xbzrle_cache_size, errp); 999 } 1000 } 1001 1002 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) 1003 { 1004 MigrationParameters tmp; 1005 1006 /* TODO Rewrite "" to null instead */ 1007 if (params->has_tls_creds 1008 && params->tls_creds->type == QTYPE_QNULL) { 1009 QDECREF(params->tls_creds->u.n); 1010 params->tls_creds->type = QTYPE_QSTRING; 1011 params->tls_creds->u.s = strdup(""); 1012 } 1013 /* TODO Rewrite "" to null instead */ 1014 if (params->has_tls_hostname 1015 && params->tls_hostname->type == QTYPE_QNULL) { 1016 QDECREF(params->tls_hostname->u.n); 1017 params->tls_hostname->type = QTYPE_QSTRING; 1018 params->tls_hostname->u.s = strdup(""); 1019 } 1020 1021 migrate_params_test_apply(params, &tmp); 1022 1023 if (!migrate_params_check(&tmp, errp)) { 1024 /* Invalid parameter */ 1025 return; 1026 } 1027 1028 migrate_params_apply(params, errp); 1029 } 1030 1031 1032 void qmp_migrate_start_postcopy(Error **errp) 1033 { 1034 MigrationState *s = migrate_get_current(); 1035 1036 if (!migrate_postcopy()) { 1037 error_setg(errp, "Enable postcopy with migrate_set_capability before" 1038 " the start of migration"); 1039 return; 1040 } 1041 1042 if (s->state == MIGRATION_STATUS_NONE) { 1043 error_setg(errp, "Postcopy must be started after migration has been" 1044 " started"); 1045 return; 1046 } 1047 /* 1048 * we don't error if migration has finished since that would be racy 1049 * with issuing this command. 1050 */ 1051 atomic_set(&s->start_postcopy, true); 1052 } 1053 1054 /* shared migration helpers */ 1055 1056 void migrate_set_state(int *state, int old_state, int new_state) 1057 { 1058 assert(new_state < MIGRATION_STATUS__MAX); 1059 if (atomic_cmpxchg(state, old_state, new_state) == old_state) { 1060 trace_migrate_set_state(MigrationStatus_str(new_state)); 1061 migrate_generate_event(new_state); 1062 } 1063 } 1064 1065 static MigrationCapabilityStatusList *migrate_cap_add( 1066 MigrationCapabilityStatusList *list, 1067 MigrationCapability index, 1068 bool state) 1069 { 1070 MigrationCapabilityStatusList *cap; 1071 1072 cap = g_new0(MigrationCapabilityStatusList, 1); 1073 cap->value = g_new0(MigrationCapabilityStatus, 1); 1074 cap->value->capability = index; 1075 cap->value->state = state; 1076 cap->next = list; 1077 1078 return cap; 1079 } 1080 1081 void migrate_set_block_enabled(bool value, Error **errp) 1082 { 1083 MigrationCapabilityStatusList *cap; 1084 1085 cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value); 1086 qmp_migrate_set_capabilities(cap, errp); 1087 qapi_free_MigrationCapabilityStatusList(cap); 1088 } 1089 1090 static void migrate_set_block_incremental(MigrationState *s, bool value) 1091 { 1092 s->parameters.block_incremental = value; 1093 } 1094 1095 static void block_cleanup_parameters(MigrationState *s) 1096 { 1097 if (s->must_remove_block_options) { 1098 /* setting to false can never fail */ 1099 migrate_set_block_enabled(false, &error_abort); 1100 migrate_set_block_incremental(s, false); 1101 s->must_remove_block_options = false; 1102 } 1103 } 1104 1105 static void migrate_fd_cleanup(void *opaque) 1106 { 1107 MigrationState *s = opaque; 1108 1109 qemu_bh_delete(s->cleanup_bh); 1110 s->cleanup_bh = NULL; 1111 1112 qemu_savevm_state_cleanup(); 1113 1114 if (s->to_dst_file) { 1115 Error *local_err = NULL; 1116 1117 trace_migrate_fd_cleanup(); 1118 qemu_mutex_unlock_iothread(); 1119 if (s->migration_thread_running) { 1120 qemu_thread_join(&s->thread); 1121 s->migration_thread_running = false; 1122 } 1123 qemu_mutex_lock_iothread(); 1124 1125 if (multifd_save_cleanup(&local_err) != 0) { 1126 error_report_err(local_err); 1127 } 1128 qemu_fclose(s->to_dst_file); 1129 s->to_dst_file = NULL; 1130 } 1131 1132 assert((s->state != MIGRATION_STATUS_ACTIVE) && 1133 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE)); 1134 1135 if (s->state == MIGRATION_STATUS_CANCELLING) { 1136 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING, 1137 MIGRATION_STATUS_CANCELLED); 1138 } 1139 1140 if (s->error) { 1141 /* It is used on info migrate. We can't free it */ 1142 error_report_err(error_copy(s->error)); 1143 } 1144 notifier_list_notify(&migration_state_notifiers, s); 1145 block_cleanup_parameters(s); 1146 } 1147 1148 void migrate_set_error(MigrationState *s, const Error *error) 1149 { 1150 qemu_mutex_lock(&s->error_mutex); 1151 if (!s->error) { 1152 s->error = error_copy(error); 1153 } 1154 qemu_mutex_unlock(&s->error_mutex); 1155 } 1156 1157 void migrate_fd_error(MigrationState *s, const Error *error) 1158 { 1159 trace_migrate_fd_error(error_get_pretty(error)); 1160 assert(s->to_dst_file == NULL); 1161 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1162 MIGRATION_STATUS_FAILED); 1163 migrate_set_error(s, error); 1164 } 1165 1166 static void migrate_fd_cancel(MigrationState *s) 1167 { 1168 int old_state ; 1169 QEMUFile *f = migrate_get_current()->to_dst_file; 1170 trace_migrate_fd_cancel(); 1171 1172 if (s->rp_state.from_dst_file) { 1173 /* shutdown the rp socket, so causing the rp thread to shutdown */ 1174 qemu_file_shutdown(s->rp_state.from_dst_file); 1175 } 1176 1177 do { 1178 old_state = s->state; 1179 if (!migration_is_setup_or_active(old_state)) { 1180 break; 1181 } 1182 /* If the migration is paused, kick it out of the pause */ 1183 if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) { 1184 qemu_sem_post(&s->pause_sem); 1185 } 1186 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING); 1187 } while (s->state != MIGRATION_STATUS_CANCELLING); 1188 1189 /* 1190 * If we're unlucky the migration code might be stuck somewhere in a 1191 * send/write while the network has failed and is waiting to timeout; 1192 * if we've got shutdown(2) available then we can force it to quit. 1193 * The outgoing qemu file gets closed in migrate_fd_cleanup that is 1194 * called in a bh, so there is no race against this cancel. 1195 */ 1196 if (s->state == MIGRATION_STATUS_CANCELLING && f) { 1197 qemu_file_shutdown(f); 1198 } 1199 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) { 1200 Error *local_err = NULL; 1201 1202 bdrv_invalidate_cache_all(&local_err); 1203 if (local_err) { 1204 error_report_err(local_err); 1205 } else { 1206 s->block_inactive = false; 1207 } 1208 } 1209 } 1210 1211 void add_migration_state_change_notifier(Notifier *notify) 1212 { 1213 notifier_list_add(&migration_state_notifiers, notify); 1214 } 1215 1216 void remove_migration_state_change_notifier(Notifier *notify) 1217 { 1218 notifier_remove(notify); 1219 } 1220 1221 bool migration_in_setup(MigrationState *s) 1222 { 1223 return s->state == MIGRATION_STATUS_SETUP; 1224 } 1225 1226 bool migration_has_finished(MigrationState *s) 1227 { 1228 return s->state == MIGRATION_STATUS_COMPLETED; 1229 } 1230 1231 bool migration_has_failed(MigrationState *s) 1232 { 1233 return (s->state == MIGRATION_STATUS_CANCELLED || 1234 s->state == MIGRATION_STATUS_FAILED); 1235 } 1236 1237 bool migration_in_postcopy(void) 1238 { 1239 MigrationState *s = migrate_get_current(); 1240 1241 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 1242 } 1243 1244 bool migration_in_postcopy_after_devices(MigrationState *s) 1245 { 1246 return migration_in_postcopy() && s->postcopy_after_devices; 1247 } 1248 1249 bool migration_is_idle(void) 1250 { 1251 MigrationState *s = migrate_get_current(); 1252 1253 switch (s->state) { 1254 case MIGRATION_STATUS_NONE: 1255 case MIGRATION_STATUS_CANCELLED: 1256 case MIGRATION_STATUS_COMPLETED: 1257 case MIGRATION_STATUS_FAILED: 1258 return true; 1259 case MIGRATION_STATUS_SETUP: 1260 case MIGRATION_STATUS_CANCELLING: 1261 case MIGRATION_STATUS_ACTIVE: 1262 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 1263 case MIGRATION_STATUS_COLO: 1264 case MIGRATION_STATUS_PRE_SWITCHOVER: 1265 case MIGRATION_STATUS_DEVICE: 1266 return false; 1267 case MIGRATION_STATUS__MAX: 1268 g_assert_not_reached(); 1269 } 1270 1271 return false; 1272 } 1273 1274 void migrate_init(MigrationState *s) 1275 { 1276 /* 1277 * Reinitialise all migration state, except 1278 * parameters/capabilities that the user set, and 1279 * locks. 1280 */ 1281 s->bytes_xfer = 0; 1282 s->xfer_limit = 0; 1283 s->cleanup_bh = 0; 1284 s->to_dst_file = NULL; 1285 s->state = MIGRATION_STATUS_NONE; 1286 s->rp_state.from_dst_file = NULL; 1287 s->rp_state.error = false; 1288 s->mbps = 0.0; 1289 s->downtime = 0; 1290 s->expected_downtime = 0; 1291 s->setup_time = 0; 1292 s->start_postcopy = false; 1293 s->postcopy_after_devices = false; 1294 s->migration_thread_running = false; 1295 error_free(s->error); 1296 s->error = NULL; 1297 1298 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); 1299 1300 s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1301 s->total_time = 0; 1302 s->vm_was_running = false; 1303 s->iteration_initial_bytes = 0; 1304 s->threshold_size = 0; 1305 } 1306 1307 static GSList *migration_blockers; 1308 1309 int migrate_add_blocker(Error *reason, Error **errp) 1310 { 1311 if (migrate_get_current()->only_migratable) { 1312 error_propagate(errp, error_copy(reason)); 1313 error_prepend(errp, "disallowing migration blocker " 1314 "(--only_migratable) for: "); 1315 return -EACCES; 1316 } 1317 1318 if (migration_is_idle()) { 1319 migration_blockers = g_slist_prepend(migration_blockers, reason); 1320 return 0; 1321 } 1322 1323 error_propagate(errp, error_copy(reason)); 1324 error_prepend(errp, "disallowing migration blocker (migration in " 1325 "progress) for: "); 1326 return -EBUSY; 1327 } 1328 1329 void migrate_del_blocker(Error *reason) 1330 { 1331 migration_blockers = g_slist_remove(migration_blockers, reason); 1332 } 1333 1334 void qmp_migrate_incoming(const char *uri, Error **errp) 1335 { 1336 Error *local_err = NULL; 1337 static bool once = true; 1338 1339 if (!deferred_incoming) { 1340 error_setg(errp, "For use with '-incoming defer'"); 1341 return; 1342 } 1343 if (!once) { 1344 error_setg(errp, "The incoming migration has already been started"); 1345 } 1346 1347 qemu_start_incoming_migration(uri, &local_err); 1348 1349 if (local_err) { 1350 error_propagate(errp, local_err); 1351 return; 1352 } 1353 1354 once = false; 1355 } 1356 1357 bool migration_is_blocked(Error **errp) 1358 { 1359 if (qemu_savevm_state_blocked(errp)) { 1360 return true; 1361 } 1362 1363 if (migration_blockers) { 1364 error_propagate(errp, error_copy(migration_blockers->data)); 1365 return true; 1366 } 1367 1368 return false; 1369 } 1370 1371 void qmp_migrate(const char *uri, bool has_blk, bool blk, 1372 bool has_inc, bool inc, bool has_detach, bool detach, 1373 Error **errp) 1374 { 1375 Error *local_err = NULL; 1376 MigrationState *s = migrate_get_current(); 1377 const char *p; 1378 1379 if (migration_is_setup_or_active(s->state) || 1380 s->state == MIGRATION_STATUS_CANCELLING || 1381 s->state == MIGRATION_STATUS_COLO) { 1382 error_setg(errp, QERR_MIGRATION_ACTIVE); 1383 return; 1384 } 1385 if (runstate_check(RUN_STATE_INMIGRATE)) { 1386 error_setg(errp, "Guest is waiting for an incoming migration"); 1387 return; 1388 } 1389 1390 if (migration_is_blocked(errp)) { 1391 return; 1392 } 1393 1394 if ((has_blk && blk) || (has_inc && inc)) { 1395 if (migrate_use_block() || migrate_use_block_incremental()) { 1396 error_setg(errp, "Command options are incompatible with " 1397 "current migration capabilities"); 1398 return; 1399 } 1400 migrate_set_block_enabled(true, &local_err); 1401 if (local_err) { 1402 error_propagate(errp, local_err); 1403 return; 1404 } 1405 s->must_remove_block_options = true; 1406 } 1407 1408 if (has_inc && inc) { 1409 migrate_set_block_incremental(s, true); 1410 } 1411 1412 migrate_init(s); 1413 1414 if (strstart(uri, "tcp:", &p)) { 1415 tcp_start_outgoing_migration(s, p, &local_err); 1416 #ifdef CONFIG_RDMA 1417 } else if (strstart(uri, "rdma:", &p)) { 1418 rdma_start_outgoing_migration(s, p, &local_err); 1419 #endif 1420 } else if (strstart(uri, "exec:", &p)) { 1421 exec_start_outgoing_migration(s, p, &local_err); 1422 } else if (strstart(uri, "unix:", &p)) { 1423 unix_start_outgoing_migration(s, p, &local_err); 1424 } else if (strstart(uri, "fd:", &p)) { 1425 fd_start_outgoing_migration(s, p, &local_err); 1426 } else { 1427 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", 1428 "a valid migration protocol"); 1429 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1430 MIGRATION_STATUS_FAILED); 1431 block_cleanup_parameters(s); 1432 return; 1433 } 1434 1435 if (local_err) { 1436 migrate_fd_error(s, local_err); 1437 error_propagate(errp, local_err); 1438 return; 1439 } 1440 } 1441 1442 void qmp_migrate_cancel(Error **errp) 1443 { 1444 migrate_fd_cancel(migrate_get_current()); 1445 } 1446 1447 void qmp_migrate_continue(MigrationStatus state, Error **errp) 1448 { 1449 MigrationState *s = migrate_get_current(); 1450 if (s->state != state) { 1451 error_setg(errp, "Migration not in expected state: %s", 1452 MigrationStatus_str(s->state)); 1453 return; 1454 } 1455 qemu_sem_post(&s->pause_sem); 1456 } 1457 1458 void qmp_migrate_set_cache_size(int64_t value, Error **errp) 1459 { 1460 MigrateSetParameters p = { 1461 .has_xbzrle_cache_size = true, 1462 .xbzrle_cache_size = value, 1463 }; 1464 1465 qmp_migrate_set_parameters(&p, errp); 1466 } 1467 1468 int64_t qmp_query_migrate_cache_size(Error **errp) 1469 { 1470 return migrate_xbzrle_cache_size(); 1471 } 1472 1473 void qmp_migrate_set_speed(int64_t value, Error **errp) 1474 { 1475 MigrateSetParameters p = { 1476 .has_max_bandwidth = true, 1477 .max_bandwidth = value, 1478 }; 1479 1480 qmp_migrate_set_parameters(&p, errp); 1481 } 1482 1483 void qmp_migrate_set_downtime(double value, Error **errp) 1484 { 1485 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) { 1486 error_setg(errp, "Parameter 'downtime_limit' expects an integer in " 1487 "the range of 0 to %d seconds", 1488 MAX_MIGRATE_DOWNTIME_SECONDS); 1489 return; 1490 } 1491 1492 value *= 1000; /* Convert to milliseconds */ 1493 value = MAX(0, MIN(INT64_MAX, value)); 1494 1495 MigrateSetParameters p = { 1496 .has_downtime_limit = true, 1497 .downtime_limit = value, 1498 }; 1499 1500 qmp_migrate_set_parameters(&p, errp); 1501 } 1502 1503 bool migrate_release_ram(void) 1504 { 1505 MigrationState *s; 1506 1507 s = migrate_get_current(); 1508 1509 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM]; 1510 } 1511 1512 bool migrate_postcopy_ram(void) 1513 { 1514 MigrationState *s; 1515 1516 s = migrate_get_current(); 1517 1518 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 1519 } 1520 1521 bool migrate_postcopy(void) 1522 { 1523 return migrate_postcopy_ram() || migrate_dirty_bitmaps(); 1524 } 1525 1526 bool migrate_auto_converge(void) 1527 { 1528 MigrationState *s; 1529 1530 s = migrate_get_current(); 1531 1532 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; 1533 } 1534 1535 bool migrate_zero_blocks(void) 1536 { 1537 MigrationState *s; 1538 1539 s = migrate_get_current(); 1540 1541 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; 1542 } 1543 1544 bool migrate_use_compression(void) 1545 { 1546 MigrationState *s; 1547 1548 s = migrate_get_current(); 1549 1550 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS]; 1551 } 1552 1553 int migrate_compress_level(void) 1554 { 1555 MigrationState *s; 1556 1557 s = migrate_get_current(); 1558 1559 return s->parameters.compress_level; 1560 } 1561 1562 int migrate_compress_threads(void) 1563 { 1564 MigrationState *s; 1565 1566 s = migrate_get_current(); 1567 1568 return s->parameters.compress_threads; 1569 } 1570 1571 int migrate_decompress_threads(void) 1572 { 1573 MigrationState *s; 1574 1575 s = migrate_get_current(); 1576 1577 return s->parameters.decompress_threads; 1578 } 1579 1580 bool migrate_dirty_bitmaps(void) 1581 { 1582 MigrationState *s; 1583 1584 s = migrate_get_current(); 1585 1586 return s->enabled_capabilities[MIGRATION_CAPABILITY_DIRTY_BITMAPS]; 1587 } 1588 1589 bool migrate_use_events(void) 1590 { 1591 MigrationState *s; 1592 1593 s = migrate_get_current(); 1594 1595 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS]; 1596 } 1597 1598 bool migrate_use_multifd(void) 1599 { 1600 MigrationState *s; 1601 1602 s = migrate_get_current(); 1603 1604 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD]; 1605 } 1606 1607 bool migrate_pause_before_switchover(void) 1608 { 1609 MigrationState *s; 1610 1611 s = migrate_get_current(); 1612 1613 return s->enabled_capabilities[ 1614 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER]; 1615 } 1616 1617 int migrate_multifd_channels(void) 1618 { 1619 MigrationState *s; 1620 1621 s = migrate_get_current(); 1622 1623 return s->parameters.x_multifd_channels; 1624 } 1625 1626 int migrate_multifd_page_count(void) 1627 { 1628 MigrationState *s; 1629 1630 s = migrate_get_current(); 1631 1632 return s->parameters.x_multifd_page_count; 1633 } 1634 1635 int migrate_use_xbzrle(void) 1636 { 1637 MigrationState *s; 1638 1639 s = migrate_get_current(); 1640 1641 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; 1642 } 1643 1644 int64_t migrate_xbzrle_cache_size(void) 1645 { 1646 MigrationState *s; 1647 1648 s = migrate_get_current(); 1649 1650 return s->parameters.xbzrle_cache_size; 1651 } 1652 1653 bool migrate_use_block(void) 1654 { 1655 MigrationState *s; 1656 1657 s = migrate_get_current(); 1658 1659 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK]; 1660 } 1661 1662 bool migrate_use_return_path(void) 1663 { 1664 MigrationState *s; 1665 1666 s = migrate_get_current(); 1667 1668 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH]; 1669 } 1670 1671 bool migrate_use_block_incremental(void) 1672 { 1673 MigrationState *s; 1674 1675 s = migrate_get_current(); 1676 1677 return s->parameters.block_incremental; 1678 } 1679 1680 /* migration thread support */ 1681 /* 1682 * Something bad happened to the RP stream, mark an error 1683 * The caller shall print or trace something to indicate why 1684 */ 1685 static void mark_source_rp_bad(MigrationState *s) 1686 { 1687 s->rp_state.error = true; 1688 } 1689 1690 static struct rp_cmd_args { 1691 ssize_t len; /* -1 = variable */ 1692 const char *name; 1693 } rp_cmd_args[] = { 1694 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, 1695 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, 1696 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, 1697 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, 1698 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, 1699 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, 1700 }; 1701 1702 /* 1703 * Process a request for pages received on the return path, 1704 * We're allowed to send more than requested (e.g. to round to our page size) 1705 * and we don't need to send pages that have already been sent. 1706 */ 1707 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, 1708 ram_addr_t start, size_t len) 1709 { 1710 long our_host_ps = getpagesize(); 1711 1712 trace_migrate_handle_rp_req_pages(rbname, start, len); 1713 1714 /* 1715 * Since we currently insist on matching page sizes, just sanity check 1716 * we're being asked for whole host pages. 1717 */ 1718 if (start & (our_host_ps-1) || 1719 (len & (our_host_ps-1))) { 1720 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT 1721 " len: %zd", __func__, start, len); 1722 mark_source_rp_bad(ms); 1723 return; 1724 } 1725 1726 if (ram_save_queue_pages(rbname, start, len)) { 1727 mark_source_rp_bad(ms); 1728 } 1729 } 1730 1731 /* 1732 * Handles messages sent on the return path towards the source VM 1733 * 1734 */ 1735 static void *source_return_path_thread(void *opaque) 1736 { 1737 MigrationState *ms = opaque; 1738 QEMUFile *rp = ms->rp_state.from_dst_file; 1739 uint16_t header_len, header_type; 1740 uint8_t buf[512]; 1741 uint32_t tmp32, sibling_error; 1742 ram_addr_t start = 0; /* =0 to silence warning */ 1743 size_t len = 0, expected_len; 1744 int res; 1745 1746 trace_source_return_path_thread_entry(); 1747 while (!ms->rp_state.error && !qemu_file_get_error(rp) && 1748 migration_is_setup_or_active(ms->state)) { 1749 trace_source_return_path_thread_loop_top(); 1750 header_type = qemu_get_be16(rp); 1751 header_len = qemu_get_be16(rp); 1752 1753 if (qemu_file_get_error(rp)) { 1754 mark_source_rp_bad(ms); 1755 goto out; 1756 } 1757 1758 if (header_type >= MIG_RP_MSG_MAX || 1759 header_type == MIG_RP_MSG_INVALID) { 1760 error_report("RP: Received invalid message 0x%04x length 0x%04x", 1761 header_type, header_len); 1762 mark_source_rp_bad(ms); 1763 goto out; 1764 } 1765 1766 if ((rp_cmd_args[header_type].len != -1 && 1767 header_len != rp_cmd_args[header_type].len) || 1768 header_len > sizeof(buf)) { 1769 error_report("RP: Received '%s' message (0x%04x) with" 1770 "incorrect length %d expecting %zu", 1771 rp_cmd_args[header_type].name, header_type, header_len, 1772 (size_t)rp_cmd_args[header_type].len); 1773 mark_source_rp_bad(ms); 1774 goto out; 1775 } 1776 1777 /* We know we've got a valid header by this point */ 1778 res = qemu_get_buffer(rp, buf, header_len); 1779 if (res != header_len) { 1780 error_report("RP: Failed reading data for message 0x%04x" 1781 " read %d expected %d", 1782 header_type, res, header_len); 1783 mark_source_rp_bad(ms); 1784 goto out; 1785 } 1786 1787 /* OK, we have the message and the data */ 1788 switch (header_type) { 1789 case MIG_RP_MSG_SHUT: 1790 sibling_error = ldl_be_p(buf); 1791 trace_source_return_path_thread_shut(sibling_error); 1792 if (sibling_error) { 1793 error_report("RP: Sibling indicated error %d", sibling_error); 1794 mark_source_rp_bad(ms); 1795 } 1796 /* 1797 * We'll let the main thread deal with closing the RP 1798 * we could do a shutdown(2) on it, but we're the only user 1799 * anyway, so there's nothing gained. 1800 */ 1801 goto out; 1802 1803 case MIG_RP_MSG_PONG: 1804 tmp32 = ldl_be_p(buf); 1805 trace_source_return_path_thread_pong(tmp32); 1806 break; 1807 1808 case MIG_RP_MSG_REQ_PAGES: 1809 start = ldq_be_p(buf); 1810 len = ldl_be_p(buf + 8); 1811 migrate_handle_rp_req_pages(ms, NULL, start, len); 1812 break; 1813 1814 case MIG_RP_MSG_REQ_PAGES_ID: 1815 expected_len = 12 + 1; /* header + termination */ 1816 1817 if (header_len >= expected_len) { 1818 start = ldq_be_p(buf); 1819 len = ldl_be_p(buf + 8); 1820 /* Now we expect an idstr */ 1821 tmp32 = buf[12]; /* Length of the following idstr */ 1822 buf[13 + tmp32] = '\0'; 1823 expected_len += tmp32; 1824 } 1825 if (header_len != expected_len) { 1826 error_report("RP: Req_Page_id with length %d expecting %zd", 1827 header_len, expected_len); 1828 mark_source_rp_bad(ms); 1829 goto out; 1830 } 1831 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); 1832 break; 1833 1834 default: 1835 break; 1836 } 1837 } 1838 if (qemu_file_get_error(rp)) { 1839 trace_source_return_path_thread_bad_end(); 1840 mark_source_rp_bad(ms); 1841 } 1842 1843 trace_source_return_path_thread_end(); 1844 out: 1845 ms->rp_state.from_dst_file = NULL; 1846 qemu_fclose(rp); 1847 return NULL; 1848 } 1849 1850 static int open_return_path_on_source(MigrationState *ms) 1851 { 1852 1853 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); 1854 if (!ms->rp_state.from_dst_file) { 1855 return -1; 1856 } 1857 1858 trace_open_return_path_on_source(); 1859 qemu_thread_create(&ms->rp_state.rp_thread, "return path", 1860 source_return_path_thread, ms, QEMU_THREAD_JOINABLE); 1861 1862 trace_open_return_path_on_source_continue(); 1863 1864 return 0; 1865 } 1866 1867 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */ 1868 static int await_return_path_close_on_source(MigrationState *ms) 1869 { 1870 /* 1871 * If this is a normal exit then the destination will send a SHUT and the 1872 * rp_thread will exit, however if there's an error we need to cause 1873 * it to exit. 1874 */ 1875 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) { 1876 /* 1877 * shutdown(2), if we have it, will cause it to unblock if it's stuck 1878 * waiting for the destination. 1879 */ 1880 qemu_file_shutdown(ms->rp_state.from_dst_file); 1881 mark_source_rp_bad(ms); 1882 } 1883 trace_await_return_path_close_on_source_joining(); 1884 qemu_thread_join(&ms->rp_state.rp_thread); 1885 trace_await_return_path_close_on_source_close(); 1886 return ms->rp_state.error; 1887 } 1888 1889 /* 1890 * Switch from normal iteration to postcopy 1891 * Returns non-0 on error 1892 */ 1893 static int postcopy_start(MigrationState *ms) 1894 { 1895 int ret; 1896 QIOChannelBuffer *bioc; 1897 QEMUFile *fb; 1898 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1899 bool restart_block = false; 1900 int cur_state = MIGRATION_STATUS_ACTIVE; 1901 if (!migrate_pause_before_switchover()) { 1902 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE, 1903 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1904 } 1905 1906 trace_postcopy_start(); 1907 qemu_mutex_lock_iothread(); 1908 trace_postcopy_start_set_run(); 1909 1910 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1911 global_state_store(); 1912 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1913 if (ret < 0) { 1914 goto fail; 1915 } 1916 1917 ret = migration_maybe_pause(ms, &cur_state, 1918 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1919 if (ret < 0) { 1920 goto fail; 1921 } 1922 1923 ret = bdrv_inactivate_all(); 1924 if (ret < 0) { 1925 goto fail; 1926 } 1927 restart_block = true; 1928 1929 /* 1930 * Cause any non-postcopiable, but iterative devices to 1931 * send out their final data. 1932 */ 1933 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false); 1934 1935 /* 1936 * in Finish migrate and with the io-lock held everything should 1937 * be quiet, but we've potentially still got dirty pages and we 1938 * need to tell the destination to throw any pages it's already received 1939 * that are dirty 1940 */ 1941 if (migrate_postcopy_ram()) { 1942 if (ram_postcopy_send_discard_bitmap(ms)) { 1943 error_report("postcopy send discard bitmap failed"); 1944 goto fail; 1945 } 1946 } 1947 1948 /* 1949 * send rest of state - note things that are doing postcopy 1950 * will notice we're in POSTCOPY_ACTIVE and not actually 1951 * wrap their state up here 1952 */ 1953 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); 1954 if (migrate_postcopy_ram()) { 1955 /* Ping just for debugging, helps line traces up */ 1956 qemu_savevm_send_ping(ms->to_dst_file, 2); 1957 } 1958 1959 /* 1960 * While loading the device state we may trigger page transfer 1961 * requests and the fd must be free to process those, and thus 1962 * the destination must read the whole device state off the fd before 1963 * it starts processing it. Unfortunately the ad-hoc migration format 1964 * doesn't allow the destination to know the size to read without fully 1965 * parsing it through each devices load-state code (especially the open 1966 * coded devices that use get/put). 1967 * So we wrap the device state up in a package with a length at the start; 1968 * to do this we use a qemu_buf to hold the whole of the device state. 1969 */ 1970 bioc = qio_channel_buffer_new(4096); 1971 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer"); 1972 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 1973 object_unref(OBJECT(bioc)); 1974 1975 /* 1976 * Make sure the receiver can get incoming pages before we send the rest 1977 * of the state 1978 */ 1979 qemu_savevm_send_postcopy_listen(fb); 1980 1981 qemu_savevm_state_complete_precopy(fb, false, false); 1982 if (migrate_postcopy_ram()) { 1983 qemu_savevm_send_ping(fb, 3); 1984 } 1985 1986 qemu_savevm_send_postcopy_run(fb); 1987 1988 /* <><> end of stuff going into the package */ 1989 1990 /* Last point of recovery; as soon as we send the package the destination 1991 * can open devices and potentially start running. 1992 * Lets just check again we've not got any errors. 1993 */ 1994 ret = qemu_file_get_error(ms->to_dst_file); 1995 if (ret) { 1996 error_report("postcopy_start: Migration stream errored (pre package)"); 1997 goto fail_closefb; 1998 } 1999 2000 restart_block = false; 2001 2002 /* Now send that blob */ 2003 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) { 2004 goto fail_closefb; 2005 } 2006 qemu_fclose(fb); 2007 2008 /* Send a notify to give a chance for anything that needs to happen 2009 * at the transition to postcopy and after the device state; in particular 2010 * spice needs to trigger a transition now 2011 */ 2012 ms->postcopy_after_devices = true; 2013 notifier_list_notify(&migration_state_notifiers, ms); 2014 2015 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop; 2016 2017 qemu_mutex_unlock_iothread(); 2018 2019 if (migrate_postcopy_ram()) { 2020 /* 2021 * Although this ping is just for debug, it could potentially be 2022 * used for getting a better measurement of downtime at the source. 2023 */ 2024 qemu_savevm_send_ping(ms->to_dst_file, 4); 2025 } 2026 2027 if (migrate_release_ram()) { 2028 ram_postcopy_migrated_memory_release(ms); 2029 } 2030 2031 ret = qemu_file_get_error(ms->to_dst_file); 2032 if (ret) { 2033 error_report("postcopy_start: Migration stream errored"); 2034 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2035 MIGRATION_STATUS_FAILED); 2036 } 2037 2038 return ret; 2039 2040 fail_closefb: 2041 qemu_fclose(fb); 2042 fail: 2043 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2044 MIGRATION_STATUS_FAILED); 2045 if (restart_block) { 2046 /* A failure happened early enough that we know the destination hasn't 2047 * accessed block devices, so we're safe to recover. 2048 */ 2049 Error *local_err = NULL; 2050 2051 bdrv_invalidate_cache_all(&local_err); 2052 if (local_err) { 2053 error_report_err(local_err); 2054 } 2055 } 2056 qemu_mutex_unlock_iothread(); 2057 return -1; 2058 } 2059 2060 /** 2061 * migration_maybe_pause: Pause if required to by 2062 * migrate_pause_before_switchover called with the iothread locked 2063 * Returns: 0 on success 2064 */ 2065 static int migration_maybe_pause(MigrationState *s, 2066 int *current_active_state, 2067 int new_state) 2068 { 2069 if (!migrate_pause_before_switchover()) { 2070 return 0; 2071 } 2072 2073 /* Since leaving this state is not atomic with posting the semaphore 2074 * it's possible that someone could have issued multiple migrate_continue 2075 * and the semaphore is incorrectly positive at this point; 2076 * the docs say it's undefined to reinit a semaphore that's already 2077 * init'd, so use timedwait to eat up any existing posts. 2078 */ 2079 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) { 2080 /* This block intentionally left blank */ 2081 } 2082 2083 qemu_mutex_unlock_iothread(); 2084 migrate_set_state(&s->state, *current_active_state, 2085 MIGRATION_STATUS_PRE_SWITCHOVER); 2086 qemu_sem_wait(&s->pause_sem); 2087 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER, 2088 new_state); 2089 *current_active_state = new_state; 2090 qemu_mutex_lock_iothread(); 2091 2092 return s->state == new_state ? 0 : -EINVAL; 2093 } 2094 2095 /** 2096 * migration_completion: Used by migration_thread when there's not much left. 2097 * The caller 'breaks' the loop when this returns. 2098 * 2099 * @s: Current migration state 2100 */ 2101 static void migration_completion(MigrationState *s) 2102 { 2103 int ret; 2104 int current_active_state = s->state; 2105 2106 if (s->state == MIGRATION_STATUS_ACTIVE) { 2107 qemu_mutex_lock_iothread(); 2108 s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2109 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 2110 s->vm_was_running = runstate_is_running(); 2111 ret = global_state_store(); 2112 2113 if (!ret) { 2114 bool inactivate = !migrate_colo_enabled(); 2115 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 2116 if (ret >= 0) { 2117 ret = migration_maybe_pause(s, ¤t_active_state, 2118 MIGRATION_STATUS_DEVICE); 2119 } 2120 if (ret >= 0) { 2121 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX); 2122 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false, 2123 inactivate); 2124 } 2125 if (inactivate && ret >= 0) { 2126 s->block_inactive = true; 2127 } 2128 } 2129 qemu_mutex_unlock_iothread(); 2130 2131 if (ret < 0) { 2132 goto fail; 2133 } 2134 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 2135 trace_migration_completion_postcopy_end(); 2136 2137 qemu_savevm_state_complete_postcopy(s->to_dst_file); 2138 trace_migration_completion_postcopy_end_after_complete(); 2139 } 2140 2141 /* 2142 * If rp was opened we must clean up the thread before 2143 * cleaning everything else up (since if there are no failures 2144 * it will wait for the destination to send it's status in 2145 * a SHUT command). 2146 */ 2147 if (s->rp_state.from_dst_file) { 2148 int rp_error; 2149 trace_migration_return_path_end_before(); 2150 rp_error = await_return_path_close_on_source(s); 2151 trace_migration_return_path_end_after(rp_error); 2152 if (rp_error) { 2153 goto fail_invalidate; 2154 } 2155 } 2156 2157 if (qemu_file_get_error(s->to_dst_file)) { 2158 trace_migration_completion_file_err(); 2159 goto fail_invalidate; 2160 } 2161 2162 if (!migrate_colo_enabled()) { 2163 migrate_set_state(&s->state, current_active_state, 2164 MIGRATION_STATUS_COMPLETED); 2165 } 2166 2167 return; 2168 2169 fail_invalidate: 2170 /* If not doing postcopy, vm_start() will be called: let's regain 2171 * control on images. 2172 */ 2173 if (s->state == MIGRATION_STATUS_ACTIVE || 2174 s->state == MIGRATION_STATUS_DEVICE) { 2175 Error *local_err = NULL; 2176 2177 qemu_mutex_lock_iothread(); 2178 bdrv_invalidate_cache_all(&local_err); 2179 if (local_err) { 2180 error_report_err(local_err); 2181 } else { 2182 s->block_inactive = false; 2183 } 2184 qemu_mutex_unlock_iothread(); 2185 } 2186 2187 fail: 2188 migrate_set_state(&s->state, current_active_state, 2189 MIGRATION_STATUS_FAILED); 2190 } 2191 2192 bool migrate_colo_enabled(void) 2193 { 2194 MigrationState *s = migrate_get_current(); 2195 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO]; 2196 } 2197 2198 static void migration_calculate_complete(MigrationState *s) 2199 { 2200 uint64_t bytes = qemu_ftell(s->to_dst_file); 2201 int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2202 2203 s->total_time = end_time - s->start_time; 2204 if (!s->downtime) { 2205 /* 2206 * It's still not set, so we are precopy migration. For 2207 * postcopy, downtime is calculated during postcopy_start(). 2208 */ 2209 s->downtime = end_time - s->downtime_start; 2210 } 2211 2212 if (s->total_time) { 2213 s->mbps = ((double) bytes * 8.0) / s->total_time / 1000; 2214 } 2215 } 2216 2217 static void migration_update_counters(MigrationState *s, 2218 int64_t current_time) 2219 { 2220 uint64_t transferred, time_spent; 2221 double bandwidth; 2222 2223 if (current_time < s->iteration_start_time + BUFFER_DELAY) { 2224 return; 2225 } 2226 2227 transferred = qemu_ftell(s->to_dst_file) - s->iteration_initial_bytes; 2228 time_spent = current_time - s->iteration_start_time; 2229 bandwidth = (double)transferred / time_spent; 2230 s->threshold_size = bandwidth * s->parameters.downtime_limit; 2231 2232 s->mbps = (((double) transferred * 8.0) / 2233 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; 2234 2235 /* 2236 * if we haven't sent anything, we don't want to 2237 * recalculate. 10000 is a small enough number for our purposes 2238 */ 2239 if (ram_counters.dirty_pages_rate && transferred > 10000) { 2240 s->expected_downtime = ram_counters.dirty_pages_rate * 2241 qemu_target_page_size() / bandwidth; 2242 } 2243 2244 qemu_file_reset_rate_limit(s->to_dst_file); 2245 2246 s->iteration_start_time = current_time; 2247 s->iteration_initial_bytes = qemu_ftell(s->to_dst_file); 2248 2249 trace_migrate_transferred(transferred, time_spent, 2250 bandwidth, s->threshold_size); 2251 } 2252 2253 /* Migration thread iteration status */ 2254 typedef enum { 2255 MIG_ITERATE_RESUME, /* Resume current iteration */ 2256 MIG_ITERATE_SKIP, /* Skip current iteration */ 2257 MIG_ITERATE_BREAK, /* Break the loop */ 2258 } MigIterateState; 2259 2260 /* 2261 * Return true if continue to the next iteration directly, false 2262 * otherwise. 2263 */ 2264 static MigIterateState migration_iteration_run(MigrationState *s) 2265 { 2266 uint64_t pending_size, pend_pre, pend_compat, pend_post; 2267 bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE; 2268 2269 qemu_savevm_state_pending(s->to_dst_file, s->threshold_size, &pend_pre, 2270 &pend_compat, &pend_post); 2271 pending_size = pend_pre + pend_compat + pend_post; 2272 2273 trace_migrate_pending(pending_size, s->threshold_size, 2274 pend_pre, pend_compat, pend_post); 2275 2276 if (pending_size && pending_size >= s->threshold_size) { 2277 /* Still a significant amount to transfer */ 2278 if (migrate_postcopy() && !in_postcopy && 2279 pend_pre <= s->threshold_size && 2280 atomic_read(&s->start_postcopy)) { 2281 if (postcopy_start(s)) { 2282 error_report("%s: postcopy failed to start", __func__); 2283 } 2284 return MIG_ITERATE_SKIP; 2285 } 2286 /* Just another iteration step */ 2287 qemu_savevm_state_iterate(s->to_dst_file, 2288 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 2289 } else { 2290 trace_migration_thread_low_pending(pending_size); 2291 migration_completion(s); 2292 return MIG_ITERATE_BREAK; 2293 } 2294 2295 return MIG_ITERATE_RESUME; 2296 } 2297 2298 static void migration_iteration_finish(MigrationState *s) 2299 { 2300 /* If we enabled cpu throttling for auto-converge, turn it off. */ 2301 cpu_throttle_stop(); 2302 2303 qemu_mutex_lock_iothread(); 2304 switch (s->state) { 2305 case MIGRATION_STATUS_COMPLETED: 2306 migration_calculate_complete(s); 2307 runstate_set(RUN_STATE_POSTMIGRATE); 2308 break; 2309 2310 case MIGRATION_STATUS_ACTIVE: 2311 /* 2312 * We should really assert here, but since it's during 2313 * migration, let's try to reduce the usage of assertions. 2314 */ 2315 if (!migrate_colo_enabled()) { 2316 error_report("%s: critical error: calling COLO code without " 2317 "COLO enabled", __func__); 2318 } 2319 migrate_start_colo_process(s); 2320 /* 2321 * Fixme: we will run VM in COLO no matter its old running state. 2322 * After exited COLO, we will keep running. 2323 */ 2324 s->vm_was_running = true; 2325 /* Fallthrough */ 2326 case MIGRATION_STATUS_FAILED: 2327 case MIGRATION_STATUS_CANCELLED: 2328 if (s->vm_was_running) { 2329 vm_start(); 2330 } else { 2331 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) { 2332 runstate_set(RUN_STATE_POSTMIGRATE); 2333 } 2334 } 2335 break; 2336 2337 default: 2338 /* Should not reach here, but if so, forgive the VM. */ 2339 error_report("%s: Unknown ending state %d", __func__, s->state); 2340 break; 2341 } 2342 qemu_bh_schedule(s->cleanup_bh); 2343 qemu_mutex_unlock_iothread(); 2344 } 2345 2346 /* 2347 * Master migration thread on the source VM. 2348 * It drives the migration and pumps the data down the outgoing channel. 2349 */ 2350 static void *migration_thread(void *opaque) 2351 { 2352 MigrationState *s = opaque; 2353 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); 2354 2355 rcu_register_thread(); 2356 2357 s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2358 2359 qemu_savevm_state_header(s->to_dst_file); 2360 2361 /* 2362 * If we opened the return path, we need to make sure dst has it 2363 * opened as well. 2364 */ 2365 if (s->rp_state.from_dst_file) { 2366 /* Now tell the dest that it should open its end so it can reply */ 2367 qemu_savevm_send_open_return_path(s->to_dst_file); 2368 2369 /* And do a ping that will make stuff easier to debug */ 2370 qemu_savevm_send_ping(s->to_dst_file, 1); 2371 } 2372 2373 if (migrate_postcopy()) { 2374 /* 2375 * Tell the destination that we *might* want to do postcopy later; 2376 * if the other end can't do postcopy it should fail now, nice and 2377 * early. 2378 */ 2379 qemu_savevm_send_postcopy_advise(s->to_dst_file); 2380 } 2381 2382 qemu_savevm_state_setup(s->to_dst_file); 2383 2384 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; 2385 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 2386 MIGRATION_STATUS_ACTIVE); 2387 2388 trace_migration_thread_setup_complete(); 2389 2390 while (s->state == MIGRATION_STATUS_ACTIVE || 2391 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 2392 int64_t current_time; 2393 2394 if (!qemu_file_rate_limit(s->to_dst_file)) { 2395 MigIterateState iter_state = migration_iteration_run(s); 2396 if (iter_state == MIG_ITERATE_SKIP) { 2397 continue; 2398 } else if (iter_state == MIG_ITERATE_BREAK) { 2399 break; 2400 } 2401 } 2402 2403 if (qemu_file_get_error(s->to_dst_file)) { 2404 if (migration_is_setup_or_active(s->state)) { 2405 migrate_set_state(&s->state, s->state, 2406 MIGRATION_STATUS_FAILED); 2407 } 2408 trace_migration_thread_file_err(); 2409 break; 2410 } 2411 2412 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2413 2414 migration_update_counters(s, current_time); 2415 2416 if (qemu_file_rate_limit(s->to_dst_file)) { 2417 /* usleep expects microseconds */ 2418 g_usleep((s->iteration_start_time + BUFFER_DELAY - 2419 current_time) * 1000); 2420 } 2421 } 2422 2423 trace_migration_thread_after_loop(); 2424 migration_iteration_finish(s); 2425 rcu_unregister_thread(); 2426 return NULL; 2427 } 2428 2429 void migrate_fd_connect(MigrationState *s, Error *error_in) 2430 { 2431 s->expected_downtime = s->parameters.downtime_limit; 2432 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); 2433 if (error_in) { 2434 migrate_fd_error(s, error_in); 2435 migrate_fd_cleanup(s); 2436 return; 2437 } 2438 2439 qemu_file_set_blocking(s->to_dst_file, true); 2440 qemu_file_set_rate_limit(s->to_dst_file, 2441 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 2442 2443 /* Notify before starting migration thread */ 2444 notifier_list_notify(&migration_state_notifiers, s); 2445 2446 /* 2447 * Open the return path. For postcopy, it is used exclusively. For 2448 * precopy, only if user specified "return-path" capability would 2449 * QEMU uses the return path. 2450 */ 2451 if (migrate_postcopy_ram() || migrate_use_return_path()) { 2452 if (open_return_path_on_source(s)) { 2453 error_report("Unable to open return-path for postcopy"); 2454 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 2455 MIGRATION_STATUS_FAILED); 2456 migrate_fd_cleanup(s); 2457 return; 2458 } 2459 } 2460 2461 if (multifd_save_setup() != 0) { 2462 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 2463 MIGRATION_STATUS_FAILED); 2464 migrate_fd_cleanup(s); 2465 return; 2466 } 2467 qemu_thread_create(&s->thread, "live_migration", migration_thread, s, 2468 QEMU_THREAD_JOINABLE); 2469 s->migration_thread_running = true; 2470 } 2471 2472 void migration_global_dump(Monitor *mon) 2473 { 2474 MigrationState *ms = migrate_get_current(); 2475 2476 monitor_printf(mon, "globals:\n"); 2477 monitor_printf(mon, "store-global-state: %s\n", 2478 ms->store_global_state ? "on" : "off"); 2479 monitor_printf(mon, "only-migratable: %s\n", 2480 ms->only_migratable ? "on" : "off"); 2481 monitor_printf(mon, "send-configuration: %s\n", 2482 ms->send_configuration ? "on" : "off"); 2483 monitor_printf(mon, "send-section-footer: %s\n", 2484 ms->send_section_footer ? "on" : "off"); 2485 } 2486 2487 #define DEFINE_PROP_MIG_CAP(name, x) \ 2488 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false) 2489 2490 static Property migration_properties[] = { 2491 DEFINE_PROP_BOOL("store-global-state", MigrationState, 2492 store_global_state, true), 2493 DEFINE_PROP_BOOL("only-migratable", MigrationState, only_migratable, false), 2494 DEFINE_PROP_BOOL("send-configuration", MigrationState, 2495 send_configuration, true), 2496 DEFINE_PROP_BOOL("send-section-footer", MigrationState, 2497 send_section_footer, true), 2498 2499 /* Migration parameters */ 2500 DEFINE_PROP_UINT8("x-compress-level", MigrationState, 2501 parameters.compress_level, 2502 DEFAULT_MIGRATE_COMPRESS_LEVEL), 2503 DEFINE_PROP_UINT8("x-compress-threads", MigrationState, 2504 parameters.compress_threads, 2505 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT), 2506 DEFINE_PROP_UINT8("x-decompress-threads", MigrationState, 2507 parameters.decompress_threads, 2508 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT), 2509 DEFINE_PROP_UINT8("x-cpu-throttle-initial", MigrationState, 2510 parameters.cpu_throttle_initial, 2511 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL), 2512 DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState, 2513 parameters.cpu_throttle_increment, 2514 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT), 2515 DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState, 2516 parameters.max_bandwidth, MAX_THROTTLE), 2517 DEFINE_PROP_UINT64("x-downtime-limit", MigrationState, 2518 parameters.downtime_limit, 2519 DEFAULT_MIGRATE_SET_DOWNTIME), 2520 DEFINE_PROP_UINT32("x-checkpoint-delay", MigrationState, 2521 parameters.x_checkpoint_delay, 2522 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY), 2523 DEFINE_PROP_UINT8("x-multifd-channels", MigrationState, 2524 parameters.x_multifd_channels, 2525 DEFAULT_MIGRATE_MULTIFD_CHANNELS), 2526 DEFINE_PROP_UINT32("x-multifd-page-count", MigrationState, 2527 parameters.x_multifd_page_count, 2528 DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT), 2529 DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState, 2530 parameters.xbzrle_cache_size, 2531 DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE), 2532 2533 /* Migration capabilities */ 2534 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE), 2535 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL), 2536 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE), 2537 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS), 2538 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS), 2539 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS), 2540 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM), 2541 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO), 2542 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM), 2543 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK), 2544 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH), 2545 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_X_MULTIFD), 2546 2547 DEFINE_PROP_END_OF_LIST(), 2548 }; 2549 2550 static void migration_class_init(ObjectClass *klass, void *data) 2551 { 2552 DeviceClass *dc = DEVICE_CLASS(klass); 2553 2554 dc->user_creatable = false; 2555 dc->props = migration_properties; 2556 } 2557 2558 static void migration_instance_finalize(Object *obj) 2559 { 2560 MigrationState *ms = MIGRATION_OBJ(obj); 2561 MigrationParameters *params = &ms->parameters; 2562 2563 qemu_mutex_destroy(&ms->error_mutex); 2564 g_free(params->tls_hostname); 2565 g_free(params->tls_creds); 2566 qemu_sem_destroy(&ms->pause_sem); 2567 error_free(ms->error); 2568 } 2569 2570 static void migration_instance_init(Object *obj) 2571 { 2572 MigrationState *ms = MIGRATION_OBJ(obj); 2573 MigrationParameters *params = &ms->parameters; 2574 2575 ms->state = MIGRATION_STATUS_NONE; 2576 ms->mbps = -1; 2577 qemu_sem_init(&ms->pause_sem, 0); 2578 qemu_mutex_init(&ms->error_mutex); 2579 2580 params->tls_hostname = g_strdup(""); 2581 params->tls_creds = g_strdup(""); 2582 2583 /* Set has_* up only for parameter checks */ 2584 params->has_compress_level = true; 2585 params->has_compress_threads = true; 2586 params->has_decompress_threads = true; 2587 params->has_cpu_throttle_initial = true; 2588 params->has_cpu_throttle_increment = true; 2589 params->has_max_bandwidth = true; 2590 params->has_downtime_limit = true; 2591 params->has_x_checkpoint_delay = true; 2592 params->has_block_incremental = true; 2593 params->has_x_multifd_channels = true; 2594 params->has_x_multifd_page_count = true; 2595 params->has_xbzrle_cache_size = true; 2596 } 2597 2598 /* 2599 * Return true if check pass, false otherwise. Error will be put 2600 * inside errp if provided. 2601 */ 2602 static bool migration_object_check(MigrationState *ms, Error **errp) 2603 { 2604 MigrationCapabilityStatusList *head = NULL; 2605 /* Assuming all off */ 2606 bool cap_list[MIGRATION_CAPABILITY__MAX] = { 0 }, ret; 2607 int i; 2608 2609 if (!migrate_params_check(&ms->parameters, errp)) { 2610 return false; 2611 } 2612 2613 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 2614 if (ms->enabled_capabilities[i]) { 2615 head = migrate_cap_add(head, i, true); 2616 } 2617 } 2618 2619 ret = migrate_caps_check(cap_list, head, errp); 2620 2621 /* It works with head == NULL */ 2622 qapi_free_MigrationCapabilityStatusList(head); 2623 2624 return ret; 2625 } 2626 2627 static const TypeInfo migration_type = { 2628 .name = TYPE_MIGRATION, 2629 /* 2630 * NOTE: TYPE_MIGRATION is not really a device, as the object is 2631 * not created using qdev_create(), it is not attached to the qdev 2632 * device tree, and it is never realized. 2633 * 2634 * TODO: Make this TYPE_OBJECT once QOM provides something like 2635 * TYPE_DEVICE's "-global" properties. 2636 */ 2637 .parent = TYPE_DEVICE, 2638 .class_init = migration_class_init, 2639 .class_size = sizeof(MigrationClass), 2640 .instance_size = sizeof(MigrationState), 2641 .instance_init = migration_instance_init, 2642 .instance_finalize = migration_instance_finalize, 2643 }; 2644 2645 static void register_migration_types(void) 2646 { 2647 type_register_static(&migration_type); 2648 } 2649 2650 type_init(register_migration_types); 2651