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 /* For incoming */ 115 static MigrationIncomingState *mis_current; 116 117 MigrationIncomingState *migration_incoming_get_current(void) 118 { 119 return mis_current; 120 } 121 122 MigrationIncomingState *migration_incoming_state_new(QEMUFile* f) 123 { 124 mis_current = g_new0(MigrationIncomingState, 1); 125 mis_current->from_src_file = f; 126 mis_current->state = MIGRATION_STATUS_NONE; 127 QLIST_INIT(&mis_current->loadvm_handlers); 128 qemu_mutex_init(&mis_current->rp_mutex); 129 qemu_event_init(&mis_current->main_thread_load_event, false); 130 131 return mis_current; 132 } 133 134 void migration_incoming_state_destroy(void) 135 { 136 qemu_event_destroy(&mis_current->main_thread_load_event); 137 loadvm_free_handlers(mis_current); 138 g_free(mis_current); 139 mis_current = NULL; 140 } 141 142 143 typedef struct { 144 bool optional; 145 uint32_t size; 146 uint8_t runstate[100]; 147 RunState state; 148 bool received; 149 } GlobalState; 150 151 static GlobalState global_state; 152 153 int global_state_store(void) 154 { 155 if (!runstate_store((char *)global_state.runstate, 156 sizeof(global_state.runstate))) { 157 error_report("runstate name too big: %s", global_state.runstate); 158 trace_migrate_state_too_big(); 159 return -EINVAL; 160 } 161 return 0; 162 } 163 164 void global_state_store_running(void) 165 { 166 const char *state = RunState_lookup[RUN_STATE_RUNNING]; 167 strncpy((char *)global_state.runstate, 168 state, sizeof(global_state.runstate)); 169 } 170 171 static bool global_state_received(void) 172 { 173 return global_state.received; 174 } 175 176 static RunState global_state_get_runstate(void) 177 { 178 return global_state.state; 179 } 180 181 void global_state_set_optional(void) 182 { 183 global_state.optional = true; 184 } 185 186 static bool global_state_needed(void *opaque) 187 { 188 GlobalState *s = opaque; 189 char *runstate = (char *)s->runstate; 190 191 /* If it is not optional, it is mandatory */ 192 193 if (s->optional == false) { 194 return true; 195 } 196 197 /* If state is running or paused, it is not needed */ 198 199 if (strcmp(runstate, "running") == 0 || 200 strcmp(runstate, "paused") == 0) { 201 return false; 202 } 203 204 /* for any other state it is needed */ 205 return true; 206 } 207 208 static int global_state_post_load(void *opaque, int version_id) 209 { 210 GlobalState *s = opaque; 211 Error *local_err = NULL; 212 int r; 213 char *runstate = (char *)s->runstate; 214 215 s->received = true; 216 trace_migrate_global_state_post_load(runstate); 217 218 r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE__MAX, 219 -1, &local_err); 220 221 if (r == -1) { 222 if (local_err) { 223 error_report_err(local_err); 224 } 225 return -EINVAL; 226 } 227 s->state = r; 228 229 return 0; 230 } 231 232 static void global_state_pre_save(void *opaque) 233 { 234 GlobalState *s = opaque; 235 236 trace_migrate_global_state_pre_save((char *)s->runstate); 237 s->size = strlen((char *)s->runstate) + 1; 238 } 239 240 static const VMStateDescription vmstate_globalstate = { 241 .name = "globalstate", 242 .version_id = 1, 243 .minimum_version_id = 1, 244 .post_load = global_state_post_load, 245 .pre_save = global_state_pre_save, 246 .needed = global_state_needed, 247 .fields = (VMStateField[]) { 248 VMSTATE_UINT32(size, GlobalState), 249 VMSTATE_BUFFER(runstate, GlobalState), 250 VMSTATE_END_OF_LIST() 251 }, 252 }; 253 254 void register_global_state(void) 255 { 256 /* We would use it independently that we receive it */ 257 strcpy((char *)&global_state.runstate, ""); 258 global_state.received = false; 259 vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); 260 } 261 262 static void migrate_generate_event(int new_state) 263 { 264 if (migrate_use_events()) { 265 qapi_event_send_migration(new_state, &error_abort); 266 } 267 } 268 269 /* 270 * Called on -incoming with a defer: uri. 271 * The migration can be started later after any parameters have been 272 * changed. 273 */ 274 static void deferred_incoming_migration(Error **errp) 275 { 276 if (deferred_incoming) { 277 error_setg(errp, "Incoming migration already deferred"); 278 } 279 deferred_incoming = true; 280 } 281 282 /* Request a range of pages from the source VM at the given 283 * start address. 284 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same 285 * as the last request (a name must have been given previously) 286 * Start: Address offset within the RB 287 * Len: Length in bytes required - must be a multiple of pagesize 288 */ 289 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, 290 ram_addr_t start, size_t len) 291 { 292 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */ 293 size_t msglen = 12; /* start + len */ 294 295 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); 296 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); 297 298 if (rbname) { 299 int rbname_len = strlen(rbname); 300 assert(rbname_len < 256); 301 302 bufc[msglen++] = rbname_len; 303 memcpy(bufc + msglen, rbname, rbname_len); 304 msglen += rbname_len; 305 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc); 306 } else { 307 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc); 308 } 309 } 310 311 void qemu_start_incoming_migration(const char *uri, Error **errp) 312 { 313 const char *p; 314 315 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort); 316 if (!strcmp(uri, "defer")) { 317 deferred_incoming_migration(errp); 318 } else if (strstart(uri, "tcp:", &p)) { 319 tcp_start_incoming_migration(p, errp); 320 #ifdef CONFIG_RDMA 321 } else if (strstart(uri, "rdma:", &p)) { 322 rdma_start_incoming_migration(p, errp); 323 #endif 324 } else if (strstart(uri, "exec:", &p)) { 325 exec_start_incoming_migration(p, errp); 326 } else if (strstart(uri, "unix:", &p)) { 327 unix_start_incoming_migration(p, errp); 328 } else if (strstart(uri, "fd:", &p)) { 329 fd_start_incoming_migration(p, errp); 330 } else { 331 error_setg(errp, "unknown migration protocol: %s", uri); 332 } 333 } 334 335 static void process_incoming_migration_bh(void *opaque) 336 { 337 Error *local_err = NULL; 338 MigrationIncomingState *mis = opaque; 339 340 /* Make sure all file formats flush their mutable metadata */ 341 bdrv_invalidate_cache_all(&local_err); 342 if (local_err) { 343 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 344 MIGRATION_STATUS_FAILED); 345 error_report_err(local_err); 346 migrate_decompress_threads_join(); 347 exit(EXIT_FAILURE); 348 } 349 350 /* 351 * This must happen after all error conditions are dealt with and 352 * we're sure the VM is going to be running on this host. 353 */ 354 qemu_announce_self(); 355 356 /* If global state section was not received or we are in running 357 state, we need to obey autostart. Any other state is set with 358 runstate_set. */ 359 360 if (!global_state_received() || 361 global_state_get_runstate() == RUN_STATE_RUNNING) { 362 if (autostart) { 363 vm_start(); 364 } else { 365 runstate_set(RUN_STATE_PAUSED); 366 } 367 } else { 368 runstate_set(global_state_get_runstate()); 369 } 370 migrate_decompress_threads_join(); 371 /* 372 * This must happen after any state changes since as soon as an external 373 * observer sees this event they might start to prod at the VM assuming 374 * it's ready to use. 375 */ 376 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 377 MIGRATION_STATUS_COMPLETED); 378 qemu_bh_delete(mis->bh); 379 migration_incoming_state_destroy(); 380 } 381 382 static void process_incoming_migration_co(void *opaque) 383 { 384 QEMUFile *f = opaque; 385 MigrationIncomingState *mis; 386 PostcopyState ps; 387 int ret; 388 389 mis = migration_incoming_state_new(f); 390 postcopy_state_set(POSTCOPY_INCOMING_NONE); 391 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE, 392 MIGRATION_STATUS_ACTIVE); 393 ret = qemu_loadvm_state(f); 394 395 ps = postcopy_state_get(); 396 trace_process_incoming_migration_co_end(ret, ps); 397 if (ps != POSTCOPY_INCOMING_NONE) { 398 if (ps == POSTCOPY_INCOMING_ADVISE) { 399 /* 400 * Where a migration had postcopy enabled (and thus went to advise) 401 * but managed to complete within the precopy period, we can use 402 * the normal exit. 403 */ 404 postcopy_ram_incoming_cleanup(mis); 405 } else if (ret >= 0) { 406 /* 407 * Postcopy was started, cleanup should happen at the end of the 408 * postcopy thread. 409 */ 410 trace_process_incoming_migration_co_postcopy_end_main(); 411 return; 412 } 413 /* Else if something went wrong then just fall out of the normal exit */ 414 } 415 416 /* we get COLO info, and know if we are in COLO mode */ 417 if (!ret && migration_incoming_enable_colo()) { 418 mis->migration_incoming_co = qemu_coroutine_self(); 419 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming", 420 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE); 421 mis->have_colo_incoming_thread = true; 422 qemu_coroutine_yield(); 423 424 /* Wait checkpoint incoming thread exit before free resource */ 425 qemu_thread_join(&mis->colo_incoming_thread); 426 } 427 428 qemu_fclose(f); 429 free_xbzrle_decoded_buf(); 430 431 if (ret < 0) { 432 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 433 MIGRATION_STATUS_FAILED); 434 error_report("load of migration failed: %s", strerror(-ret)); 435 migrate_decompress_threads_join(); 436 exit(EXIT_FAILURE); 437 } 438 439 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); 440 qemu_bh_schedule(mis->bh); 441 } 442 443 void migration_fd_process_incoming(QEMUFile *f) 444 { 445 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, f); 446 447 migrate_decompress_threads_create(); 448 qemu_file_set_blocking(f, false); 449 qemu_coroutine_enter(co); 450 } 451 452 453 void migration_channel_process_incoming(MigrationState *s, 454 QIOChannel *ioc) 455 { 456 trace_migration_set_incoming_channel( 457 ioc, object_get_typename(OBJECT(ioc))); 458 459 if (s->parameters.tls_creds && 460 !object_dynamic_cast(OBJECT(ioc), 461 TYPE_QIO_CHANNEL_TLS)) { 462 Error *local_err = NULL; 463 migration_tls_channel_process_incoming(s, ioc, &local_err); 464 if (local_err) { 465 error_report_err(local_err); 466 } 467 } else { 468 QEMUFile *f = qemu_fopen_channel_input(ioc); 469 migration_fd_process_incoming(f); 470 } 471 } 472 473 474 void migration_channel_connect(MigrationState *s, 475 QIOChannel *ioc, 476 const char *hostname) 477 { 478 trace_migration_set_outgoing_channel( 479 ioc, object_get_typename(OBJECT(ioc)), hostname); 480 481 if (s->parameters.tls_creds && 482 !object_dynamic_cast(OBJECT(ioc), 483 TYPE_QIO_CHANNEL_TLS)) { 484 Error *local_err = NULL; 485 migration_tls_channel_connect(s, ioc, hostname, &local_err); 486 if (local_err) { 487 migrate_fd_error(s, local_err); 488 error_free(local_err); 489 } 490 } else { 491 QEMUFile *f = qemu_fopen_channel_output(ioc); 492 493 s->to_dst_file = f; 494 495 migrate_fd_connect(s); 496 } 497 } 498 499 500 /* 501 * Send a message on the return channel back to the source 502 * of the migration. 503 */ 504 void migrate_send_rp_message(MigrationIncomingState *mis, 505 enum mig_rp_message_type message_type, 506 uint16_t len, void *data) 507 { 508 trace_migrate_send_rp_message((int)message_type, len); 509 qemu_mutex_lock(&mis->rp_mutex); 510 qemu_put_be16(mis->to_src_file, (unsigned int)message_type); 511 qemu_put_be16(mis->to_src_file, len); 512 qemu_put_buffer(mis->to_src_file, data, len); 513 qemu_fflush(mis->to_src_file); 514 qemu_mutex_unlock(&mis->rp_mutex); 515 } 516 517 /* 518 * Send a 'SHUT' message on the return channel with the given value 519 * to indicate that we've finished with the RP. Non-0 value indicates 520 * error. 521 */ 522 void migrate_send_rp_shut(MigrationIncomingState *mis, 523 uint32_t value) 524 { 525 uint32_t buf; 526 527 buf = cpu_to_be32(value); 528 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); 529 } 530 531 /* 532 * Send a 'PONG' message on the return channel with the given value 533 * (normally in response to a 'PING') 534 */ 535 void migrate_send_rp_pong(MigrationIncomingState *mis, 536 uint32_t value) 537 { 538 uint32_t buf; 539 540 buf = cpu_to_be32(value); 541 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); 542 } 543 544 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) 545 { 546 MigrationCapabilityStatusList *head = NULL; 547 MigrationCapabilityStatusList *caps; 548 MigrationState *s = migrate_get_current(); 549 int i; 550 551 caps = NULL; /* silence compiler warning */ 552 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 553 if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) { 554 continue; 555 } 556 if (head == NULL) { 557 head = g_malloc0(sizeof(*caps)); 558 caps = head; 559 } else { 560 caps->next = g_malloc0(sizeof(*caps)); 561 caps = caps->next; 562 } 563 caps->value = 564 g_malloc(sizeof(*caps->value)); 565 caps->value->capability = i; 566 caps->value->state = s->enabled_capabilities[i]; 567 } 568 569 return head; 570 } 571 572 MigrationParameters *qmp_query_migrate_parameters(Error **errp) 573 { 574 MigrationParameters *params; 575 MigrationState *s = migrate_get_current(); 576 577 params = g_malloc0(sizeof(*params)); 578 params->has_compress_level = true; 579 params->compress_level = s->parameters.compress_level; 580 params->has_compress_threads = true; 581 params->compress_threads = s->parameters.compress_threads; 582 params->has_decompress_threads = true; 583 params->decompress_threads = s->parameters.decompress_threads; 584 params->has_cpu_throttle_initial = true; 585 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; 586 params->has_cpu_throttle_increment = true; 587 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; 588 params->has_tls_creds = !!s->parameters.tls_creds; 589 params->tls_creds = g_strdup(s->parameters.tls_creds); 590 params->has_tls_hostname = !!s->parameters.tls_hostname; 591 params->tls_hostname = g_strdup(s->parameters.tls_hostname); 592 params->has_max_bandwidth = true; 593 params->max_bandwidth = s->parameters.max_bandwidth; 594 params->has_downtime_limit = true; 595 params->downtime_limit = s->parameters.downtime_limit; 596 params->has_x_checkpoint_delay = true; 597 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay; 598 599 return params; 600 } 601 602 /* 603 * Return true if we're already in the middle of a migration 604 * (i.e. any of the active or setup states) 605 */ 606 static bool migration_is_setup_or_active(int state) 607 { 608 switch (state) { 609 case MIGRATION_STATUS_ACTIVE: 610 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 611 case MIGRATION_STATUS_SETUP: 612 return true; 613 614 default: 615 return false; 616 617 } 618 } 619 620 static void get_xbzrle_cache_stats(MigrationInfo *info) 621 { 622 if (migrate_use_xbzrle()) { 623 info->has_xbzrle_cache = true; 624 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); 625 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); 626 info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred(); 627 info->xbzrle_cache->pages = xbzrle_mig_pages_transferred(); 628 info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss(); 629 info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate(); 630 info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow(); 631 } 632 } 633 634 static void populate_ram_info(MigrationInfo *info, MigrationState *s) 635 { 636 info->has_ram = true; 637 info->ram = g_malloc0(sizeof(*info->ram)); 638 info->ram->transferred = ram_bytes_transferred(); 639 info->ram->total = ram_bytes_total(); 640 info->ram->duplicate = dup_mig_pages_transferred(); 641 info->ram->skipped = skipped_mig_pages_transferred(); 642 info->ram->normal = norm_mig_pages_transferred(); 643 info->ram->normal_bytes = norm_mig_bytes_transferred(); 644 info->ram->mbps = s->mbps; 645 info->ram->dirty_sync_count = s->dirty_sync_count; 646 info->ram->postcopy_requests = s->postcopy_requests; 647 648 if (s->state != MIGRATION_STATUS_COMPLETED) { 649 info->ram->remaining = ram_bytes_remaining(); 650 info->ram->dirty_pages_rate = s->dirty_pages_rate; 651 } 652 } 653 654 MigrationInfo *qmp_query_migrate(Error **errp) 655 { 656 MigrationInfo *info = g_malloc0(sizeof(*info)); 657 MigrationState *s = migrate_get_current(); 658 659 switch (s->state) { 660 case MIGRATION_STATUS_NONE: 661 /* no migration has happened ever */ 662 break; 663 case MIGRATION_STATUS_SETUP: 664 info->has_status = true; 665 info->has_total_time = false; 666 break; 667 case MIGRATION_STATUS_ACTIVE: 668 case MIGRATION_STATUS_CANCELLING: 669 info->has_status = true; 670 info->has_total_time = true; 671 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 672 - s->total_time; 673 info->has_expected_downtime = true; 674 info->expected_downtime = s->expected_downtime; 675 info->has_setup_time = true; 676 info->setup_time = s->setup_time; 677 678 populate_ram_info(info, s); 679 680 if (blk_mig_active()) { 681 info->has_disk = true; 682 info->disk = g_malloc0(sizeof(*info->disk)); 683 info->disk->transferred = blk_mig_bytes_transferred(); 684 info->disk->remaining = blk_mig_bytes_remaining(); 685 info->disk->total = blk_mig_bytes_total(); 686 } 687 688 if (cpu_throttle_active()) { 689 info->has_cpu_throttle_percentage = true; 690 info->cpu_throttle_percentage = cpu_throttle_get_percentage(); 691 } 692 693 get_xbzrle_cache_stats(info); 694 break; 695 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 696 /* Mostly the same as active; TODO add some postcopy stats */ 697 info->has_status = true; 698 info->has_total_time = true; 699 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 700 - s->total_time; 701 info->has_expected_downtime = true; 702 info->expected_downtime = s->expected_downtime; 703 info->has_setup_time = true; 704 info->setup_time = s->setup_time; 705 706 populate_ram_info(info, s); 707 708 if (blk_mig_active()) { 709 info->has_disk = true; 710 info->disk = g_malloc0(sizeof(*info->disk)); 711 info->disk->transferred = blk_mig_bytes_transferred(); 712 info->disk->remaining = blk_mig_bytes_remaining(); 713 info->disk->total = blk_mig_bytes_total(); 714 } 715 716 get_xbzrle_cache_stats(info); 717 break; 718 case MIGRATION_STATUS_COLO: 719 info->has_status = true; 720 /* TODO: display COLO specific information (checkpoint info etc.) */ 721 break; 722 case MIGRATION_STATUS_COMPLETED: 723 get_xbzrle_cache_stats(info); 724 725 info->has_status = true; 726 info->has_total_time = true; 727 info->total_time = s->total_time; 728 info->has_downtime = true; 729 info->downtime = s->downtime; 730 info->has_setup_time = true; 731 info->setup_time = s->setup_time; 732 733 populate_ram_info(info, s); 734 break; 735 case MIGRATION_STATUS_FAILED: 736 info->has_status = true; 737 if (s->error) { 738 info->has_error_desc = true; 739 info->error_desc = g_strdup(error_get_pretty(s->error)); 740 } 741 break; 742 case MIGRATION_STATUS_CANCELLED: 743 info->has_status = true; 744 break; 745 } 746 info->status = s->state; 747 748 return info; 749 } 750 751 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 752 Error **errp) 753 { 754 MigrationState *s = migrate_get_current(); 755 MigrationCapabilityStatusList *cap; 756 bool old_postcopy_cap = migrate_postcopy_ram(); 757 758 if (migration_is_setup_or_active(s->state)) { 759 error_setg(errp, QERR_MIGRATION_ACTIVE); 760 return; 761 } 762 763 for (cap = params; cap; cap = cap->next) { 764 if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) { 765 if (!colo_supported()) { 766 error_setg(errp, "COLO is not currently supported, please" 767 " configure with --enable-colo option in order to" 768 " support COLO feature"); 769 continue; 770 } 771 } 772 s->enabled_capabilities[cap->value->capability] = cap->value->state; 773 } 774 775 if (migrate_postcopy_ram()) { 776 if (migrate_use_compression()) { 777 /* The decompression threads asynchronously write into RAM 778 * rather than use the atomic copies needed to avoid 779 * userfaulting. It should be possible to fix the decompression 780 * threads for compatibility in future. 781 */ 782 error_report("Postcopy is not currently compatible with " 783 "compression"); 784 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] = 785 false; 786 } 787 /* This check is reasonably expensive, so only when it's being 788 * set the first time, also it's only the destination that needs 789 * special support. 790 */ 791 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) && 792 !postcopy_ram_supported_by_host()) { 793 /* postcopy_ram_supported_by_host will have emitted a more 794 * detailed message 795 */ 796 error_report("Postcopy is not supported"); 797 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] = 798 false; 799 } 800 } 801 } 802 803 void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp) 804 { 805 MigrationState *s = migrate_get_current(); 806 807 if (params->has_compress_level && 808 (params->compress_level < 0 || params->compress_level > 9)) { 809 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level", 810 "is invalid, it should be in the range of 0 to 9"); 811 return; 812 } 813 if (params->has_compress_threads && 814 (params->compress_threads < 1 || params->compress_threads > 255)) { 815 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 816 "compress_threads", 817 "is invalid, it should be in the range of 1 to 255"); 818 return; 819 } 820 if (params->has_decompress_threads && 821 (params->decompress_threads < 1 || params->decompress_threads > 255)) { 822 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 823 "decompress_threads", 824 "is invalid, it should be in the range of 1 to 255"); 825 return; 826 } 827 if (params->has_cpu_throttle_initial && 828 (params->cpu_throttle_initial < 1 || 829 params->cpu_throttle_initial > 99)) { 830 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 831 "cpu_throttle_initial", 832 "an integer in the range of 1 to 99"); 833 return; 834 } 835 if (params->has_cpu_throttle_increment && 836 (params->cpu_throttle_increment < 1 || 837 params->cpu_throttle_increment > 99)) { 838 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 839 "cpu_throttle_increment", 840 "an integer in the range of 1 to 99"); 841 return; 842 } 843 if (params->has_max_bandwidth && 844 (params->max_bandwidth < 0 || params->max_bandwidth > SIZE_MAX)) { 845 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the" 846 " range of 0 to %zu bytes/second", SIZE_MAX); 847 return; 848 } 849 if (params->has_downtime_limit && 850 (params->downtime_limit < 0 || params->downtime_limit > 2000000)) { 851 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 852 "downtime_limit", 853 "an integer in the range of 0 to 2000000 milliseconds"); 854 return; 855 } 856 if (params->has_x_checkpoint_delay && (params->x_checkpoint_delay < 0)) { 857 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 858 "x_checkpoint_delay", 859 "is invalid, it should be positive"); 860 } 861 862 if (params->has_compress_level) { 863 s->parameters.compress_level = params->compress_level; 864 } 865 if (params->has_compress_threads) { 866 s->parameters.compress_threads = params->compress_threads; 867 } 868 if (params->has_decompress_threads) { 869 s->parameters.decompress_threads = params->decompress_threads; 870 } 871 if (params->has_cpu_throttle_initial) { 872 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial; 873 } 874 if (params->has_cpu_throttle_increment) { 875 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; 876 } 877 if (params->has_tls_creds) { 878 g_free(s->parameters.tls_creds); 879 s->parameters.tls_creds = g_strdup(params->tls_creds); 880 } 881 if (params->has_tls_hostname) { 882 g_free(s->parameters.tls_hostname); 883 s->parameters.tls_hostname = g_strdup(params->tls_hostname); 884 } 885 if (params->has_max_bandwidth) { 886 s->parameters.max_bandwidth = params->max_bandwidth; 887 if (s->to_dst_file) { 888 qemu_file_set_rate_limit(s->to_dst_file, 889 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 890 } 891 } 892 if (params->has_downtime_limit) { 893 s->parameters.downtime_limit = params->downtime_limit; 894 } 895 896 if (params->has_x_checkpoint_delay) { 897 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay; 898 } 899 } 900 901 902 void qmp_migrate_start_postcopy(Error **errp) 903 { 904 MigrationState *s = migrate_get_current(); 905 906 if (!migrate_postcopy_ram()) { 907 error_setg(errp, "Enable postcopy with migrate_set_capability before" 908 " the start of migration"); 909 return; 910 } 911 912 if (s->state == MIGRATION_STATUS_NONE) { 913 error_setg(errp, "Postcopy must be started after migration has been" 914 " started"); 915 return; 916 } 917 /* 918 * we don't error if migration has finished since that would be racy 919 * with issuing this command. 920 */ 921 atomic_set(&s->start_postcopy, true); 922 } 923 924 /* shared migration helpers */ 925 926 void migrate_set_state(int *state, int old_state, int new_state) 927 { 928 if (atomic_cmpxchg(state, old_state, new_state) == old_state) { 929 trace_migrate_set_state(new_state); 930 migrate_generate_event(new_state); 931 } 932 } 933 934 static void migrate_fd_cleanup(void *opaque) 935 { 936 MigrationState *s = opaque; 937 938 qemu_bh_delete(s->cleanup_bh); 939 s->cleanup_bh = NULL; 940 941 flush_page_queue(s); 942 943 if (s->to_dst_file) { 944 trace_migrate_fd_cleanup(); 945 qemu_mutex_unlock_iothread(); 946 if (s->migration_thread_running) { 947 qemu_thread_join(&s->thread); 948 s->migration_thread_running = false; 949 } 950 qemu_mutex_lock_iothread(); 951 952 migrate_compress_threads_join(); 953 qemu_fclose(s->to_dst_file); 954 s->to_dst_file = NULL; 955 } 956 957 assert((s->state != MIGRATION_STATUS_ACTIVE) && 958 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE)); 959 960 if (s->state == MIGRATION_STATUS_CANCELLING) { 961 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING, 962 MIGRATION_STATUS_CANCELLED); 963 } 964 965 notifier_list_notify(&migration_state_notifiers, s); 966 } 967 968 void migrate_fd_error(MigrationState *s, const Error *error) 969 { 970 trace_migrate_fd_error(error_get_pretty(error)); 971 assert(s->to_dst_file == NULL); 972 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 973 MIGRATION_STATUS_FAILED); 974 if (!s->error) { 975 s->error = error_copy(error); 976 } 977 notifier_list_notify(&migration_state_notifiers, s); 978 } 979 980 static void migrate_fd_cancel(MigrationState *s) 981 { 982 int old_state ; 983 QEMUFile *f = migrate_get_current()->to_dst_file; 984 trace_migrate_fd_cancel(); 985 986 if (s->rp_state.from_dst_file) { 987 /* shutdown the rp socket, so causing the rp thread to shutdown */ 988 qemu_file_shutdown(s->rp_state.from_dst_file); 989 } 990 991 do { 992 old_state = s->state; 993 if (!migration_is_setup_or_active(old_state)) { 994 break; 995 } 996 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING); 997 } while (s->state != MIGRATION_STATUS_CANCELLING); 998 999 /* 1000 * If we're unlucky the migration code might be stuck somewhere in a 1001 * send/write while the network has failed and is waiting to timeout; 1002 * if we've got shutdown(2) available then we can force it to quit. 1003 * The outgoing qemu file gets closed in migrate_fd_cleanup that is 1004 * called in a bh, so there is no race against this cancel. 1005 */ 1006 if (s->state == MIGRATION_STATUS_CANCELLING && f) { 1007 qemu_file_shutdown(f); 1008 } 1009 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) { 1010 Error *local_err = NULL; 1011 1012 bdrv_invalidate_cache_all(&local_err); 1013 if (local_err) { 1014 error_report_err(local_err); 1015 } else { 1016 s->block_inactive = false; 1017 } 1018 } 1019 } 1020 1021 void add_migration_state_change_notifier(Notifier *notify) 1022 { 1023 notifier_list_add(&migration_state_notifiers, notify); 1024 } 1025 1026 void remove_migration_state_change_notifier(Notifier *notify) 1027 { 1028 notifier_remove(notify); 1029 } 1030 1031 bool migration_in_setup(MigrationState *s) 1032 { 1033 return s->state == MIGRATION_STATUS_SETUP; 1034 } 1035 1036 bool migration_has_finished(MigrationState *s) 1037 { 1038 return s->state == MIGRATION_STATUS_COMPLETED; 1039 } 1040 1041 bool migration_has_failed(MigrationState *s) 1042 { 1043 return (s->state == MIGRATION_STATUS_CANCELLED || 1044 s->state == MIGRATION_STATUS_FAILED); 1045 } 1046 1047 bool migration_in_postcopy(MigrationState *s) 1048 { 1049 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 1050 } 1051 1052 bool migration_in_postcopy_after_devices(MigrationState *s) 1053 { 1054 return migration_in_postcopy(s) && s->postcopy_after_devices; 1055 } 1056 1057 bool migration_is_idle(MigrationState *s) 1058 { 1059 if (!s) { 1060 s = migrate_get_current(); 1061 } 1062 1063 switch (s->state) { 1064 case MIGRATION_STATUS_NONE: 1065 case MIGRATION_STATUS_CANCELLED: 1066 case MIGRATION_STATUS_COMPLETED: 1067 case MIGRATION_STATUS_FAILED: 1068 return true; 1069 case MIGRATION_STATUS_SETUP: 1070 case MIGRATION_STATUS_CANCELLING: 1071 case MIGRATION_STATUS_ACTIVE: 1072 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 1073 case MIGRATION_STATUS_COLO: 1074 return false; 1075 case MIGRATION_STATUS__MAX: 1076 g_assert_not_reached(); 1077 } 1078 1079 return false; 1080 } 1081 1082 MigrationState *migrate_init(const MigrationParams *params) 1083 { 1084 MigrationState *s = migrate_get_current(); 1085 1086 /* 1087 * Reinitialise all migration state, except 1088 * parameters/capabilities that the user set, and 1089 * locks. 1090 */ 1091 s->bytes_xfer = 0; 1092 s->xfer_limit = 0; 1093 s->cleanup_bh = 0; 1094 s->to_dst_file = NULL; 1095 s->state = MIGRATION_STATUS_NONE; 1096 s->params = *params; 1097 s->rp_state.from_dst_file = NULL; 1098 s->rp_state.error = false; 1099 s->mbps = 0.0; 1100 s->downtime = 0; 1101 s->expected_downtime = 0; 1102 s->dirty_pages_rate = 0; 1103 s->dirty_bytes_rate = 0; 1104 s->setup_time = 0; 1105 s->dirty_sync_count = 0; 1106 s->start_postcopy = false; 1107 s->postcopy_after_devices = false; 1108 s->postcopy_requests = 0; 1109 s->migration_thread_running = false; 1110 s->last_req_rb = NULL; 1111 error_free(s->error); 1112 s->error = NULL; 1113 1114 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); 1115 1116 QSIMPLEQ_INIT(&s->src_page_requests); 1117 1118 s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1119 return s; 1120 } 1121 1122 static GSList *migration_blockers; 1123 1124 int migrate_add_blocker(Error *reason, Error **errp) 1125 { 1126 if (only_migratable) { 1127 error_propagate(errp, error_copy(reason)); 1128 error_prepend(errp, "disallowing migration blocker " 1129 "(--only_migratable) for: "); 1130 return -EACCES; 1131 } 1132 1133 if (migration_is_idle(NULL)) { 1134 migration_blockers = g_slist_prepend(migration_blockers, reason); 1135 return 0; 1136 } 1137 1138 error_propagate(errp, error_copy(reason)); 1139 error_prepend(errp, "disallowing migration blocker (migration in " 1140 "progress) for: "); 1141 return -EBUSY; 1142 } 1143 1144 void migrate_del_blocker(Error *reason) 1145 { 1146 migration_blockers = g_slist_remove(migration_blockers, reason); 1147 } 1148 1149 void qmp_migrate_incoming(const char *uri, Error **errp) 1150 { 1151 Error *local_err = NULL; 1152 static bool once = true; 1153 1154 if (!deferred_incoming) { 1155 error_setg(errp, "For use with '-incoming defer'"); 1156 return; 1157 } 1158 if (!once) { 1159 error_setg(errp, "The incoming migration has already been started"); 1160 } 1161 1162 qemu_start_incoming_migration(uri, &local_err); 1163 1164 if (local_err) { 1165 error_propagate(errp, local_err); 1166 return; 1167 } 1168 1169 once = false; 1170 } 1171 1172 bool migration_is_blocked(Error **errp) 1173 { 1174 if (qemu_savevm_state_blocked(errp)) { 1175 return true; 1176 } 1177 1178 if (migration_blockers) { 1179 *errp = error_copy(migration_blockers->data); 1180 return true; 1181 } 1182 1183 return false; 1184 } 1185 1186 void qmp_migrate(const char *uri, bool has_blk, bool blk, 1187 bool has_inc, bool inc, bool has_detach, bool detach, 1188 Error **errp) 1189 { 1190 Error *local_err = NULL; 1191 MigrationState *s = migrate_get_current(); 1192 MigrationParams params; 1193 const char *p; 1194 1195 params.blk = has_blk && blk; 1196 params.shared = has_inc && inc; 1197 1198 if (migration_is_setup_or_active(s->state) || 1199 s->state == MIGRATION_STATUS_CANCELLING || 1200 s->state == MIGRATION_STATUS_COLO) { 1201 error_setg(errp, QERR_MIGRATION_ACTIVE); 1202 return; 1203 } 1204 if (runstate_check(RUN_STATE_INMIGRATE)) { 1205 error_setg(errp, "Guest is waiting for an incoming migration"); 1206 return; 1207 } 1208 1209 if (migration_is_blocked(errp)) { 1210 return; 1211 } 1212 1213 s = migrate_init(¶ms); 1214 1215 if (strstart(uri, "tcp:", &p)) { 1216 tcp_start_outgoing_migration(s, p, &local_err); 1217 #ifdef CONFIG_RDMA 1218 } else if (strstart(uri, "rdma:", &p)) { 1219 rdma_start_outgoing_migration(s, p, &local_err); 1220 #endif 1221 } else if (strstart(uri, "exec:", &p)) { 1222 exec_start_outgoing_migration(s, p, &local_err); 1223 } else if (strstart(uri, "unix:", &p)) { 1224 unix_start_outgoing_migration(s, p, &local_err); 1225 } else if (strstart(uri, "fd:", &p)) { 1226 fd_start_outgoing_migration(s, p, &local_err); 1227 } else { 1228 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", 1229 "a valid migration protocol"); 1230 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1231 MIGRATION_STATUS_FAILED); 1232 return; 1233 } 1234 1235 if (local_err) { 1236 migrate_fd_error(s, local_err); 1237 error_propagate(errp, local_err); 1238 return; 1239 } 1240 } 1241 1242 void qmp_migrate_cancel(Error **errp) 1243 { 1244 migrate_fd_cancel(migrate_get_current()); 1245 } 1246 1247 void qmp_migrate_set_cache_size(int64_t value, Error **errp) 1248 { 1249 MigrationState *s = migrate_get_current(); 1250 int64_t new_size; 1251 1252 /* Check for truncation */ 1253 if (value != (size_t)value) { 1254 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1255 "exceeding address space"); 1256 return; 1257 } 1258 1259 /* Cache should not be larger than guest ram size */ 1260 if (value > ram_bytes_total()) { 1261 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1262 "exceeds guest ram size "); 1263 return; 1264 } 1265 1266 new_size = xbzrle_cache_resize(value); 1267 if (new_size < 0) { 1268 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1269 "is smaller than page size"); 1270 return; 1271 } 1272 1273 s->xbzrle_cache_size = new_size; 1274 } 1275 1276 int64_t qmp_query_migrate_cache_size(Error **errp) 1277 { 1278 return migrate_xbzrle_cache_size(); 1279 } 1280 1281 void qmp_migrate_set_speed(int64_t value, Error **errp) 1282 { 1283 MigrationParameters p = { 1284 .has_max_bandwidth = true, 1285 .max_bandwidth = value, 1286 }; 1287 1288 qmp_migrate_set_parameters(&p, errp); 1289 } 1290 1291 void qmp_migrate_set_downtime(double value, Error **errp) 1292 { 1293 value *= 1000; /* Convert to milliseconds */ 1294 value = MAX(0, MIN(INT64_MAX, value)); 1295 1296 MigrationParameters p = { 1297 .has_downtime_limit = true, 1298 .downtime_limit = value, 1299 }; 1300 1301 qmp_migrate_set_parameters(&p, errp); 1302 } 1303 1304 bool migrate_postcopy_ram(void) 1305 { 1306 MigrationState *s; 1307 1308 s = migrate_get_current(); 1309 1310 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 1311 } 1312 1313 bool migrate_auto_converge(void) 1314 { 1315 MigrationState *s; 1316 1317 s = migrate_get_current(); 1318 1319 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; 1320 } 1321 1322 bool migrate_zero_blocks(void) 1323 { 1324 MigrationState *s; 1325 1326 s = migrate_get_current(); 1327 1328 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; 1329 } 1330 1331 bool migrate_use_compression(void) 1332 { 1333 MigrationState *s; 1334 1335 s = migrate_get_current(); 1336 1337 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS]; 1338 } 1339 1340 int migrate_compress_level(void) 1341 { 1342 MigrationState *s; 1343 1344 s = migrate_get_current(); 1345 1346 return s->parameters.compress_level; 1347 } 1348 1349 int migrate_compress_threads(void) 1350 { 1351 MigrationState *s; 1352 1353 s = migrate_get_current(); 1354 1355 return s->parameters.compress_threads; 1356 } 1357 1358 int migrate_decompress_threads(void) 1359 { 1360 MigrationState *s; 1361 1362 s = migrate_get_current(); 1363 1364 return s->parameters.decompress_threads; 1365 } 1366 1367 bool migrate_use_events(void) 1368 { 1369 MigrationState *s; 1370 1371 s = migrate_get_current(); 1372 1373 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS]; 1374 } 1375 1376 int migrate_use_xbzrle(void) 1377 { 1378 MigrationState *s; 1379 1380 s = migrate_get_current(); 1381 1382 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; 1383 } 1384 1385 int64_t migrate_xbzrle_cache_size(void) 1386 { 1387 MigrationState *s; 1388 1389 s = migrate_get_current(); 1390 1391 return s->xbzrle_cache_size; 1392 } 1393 1394 /* migration thread support */ 1395 /* 1396 * Something bad happened to the RP stream, mark an error 1397 * The caller shall print or trace something to indicate why 1398 */ 1399 static void mark_source_rp_bad(MigrationState *s) 1400 { 1401 s->rp_state.error = true; 1402 } 1403 1404 static struct rp_cmd_args { 1405 ssize_t len; /* -1 = variable */ 1406 const char *name; 1407 } rp_cmd_args[] = { 1408 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, 1409 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, 1410 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, 1411 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, 1412 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, 1413 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, 1414 }; 1415 1416 /* 1417 * Process a request for pages received on the return path, 1418 * We're allowed to send more than requested (e.g. to round to our page size) 1419 * and we don't need to send pages that have already been sent. 1420 */ 1421 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, 1422 ram_addr_t start, size_t len) 1423 { 1424 long our_host_ps = getpagesize(); 1425 1426 trace_migrate_handle_rp_req_pages(rbname, start, len); 1427 1428 /* 1429 * Since we currently insist on matching page sizes, just sanity check 1430 * we're being asked for whole host pages. 1431 */ 1432 if (start & (our_host_ps-1) || 1433 (len & (our_host_ps-1))) { 1434 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT 1435 " len: %zd", __func__, start, len); 1436 mark_source_rp_bad(ms); 1437 return; 1438 } 1439 1440 if (ram_save_queue_pages(ms, rbname, start, len)) { 1441 mark_source_rp_bad(ms); 1442 } 1443 } 1444 1445 /* 1446 * Handles messages sent on the return path towards the source VM 1447 * 1448 */ 1449 static void *source_return_path_thread(void *opaque) 1450 { 1451 MigrationState *ms = opaque; 1452 QEMUFile *rp = ms->rp_state.from_dst_file; 1453 uint16_t header_len, header_type; 1454 uint8_t buf[512]; 1455 uint32_t tmp32, sibling_error; 1456 ram_addr_t start = 0; /* =0 to silence warning */ 1457 size_t len = 0, expected_len; 1458 int res; 1459 1460 trace_source_return_path_thread_entry(); 1461 while (!ms->rp_state.error && !qemu_file_get_error(rp) && 1462 migration_is_setup_or_active(ms->state)) { 1463 trace_source_return_path_thread_loop_top(); 1464 header_type = qemu_get_be16(rp); 1465 header_len = qemu_get_be16(rp); 1466 1467 if (header_type >= MIG_RP_MSG_MAX || 1468 header_type == MIG_RP_MSG_INVALID) { 1469 error_report("RP: Received invalid message 0x%04x length 0x%04x", 1470 header_type, header_len); 1471 mark_source_rp_bad(ms); 1472 goto out; 1473 } 1474 1475 if ((rp_cmd_args[header_type].len != -1 && 1476 header_len != rp_cmd_args[header_type].len) || 1477 header_len > sizeof(buf)) { 1478 error_report("RP: Received '%s' message (0x%04x) with" 1479 "incorrect length %d expecting %zu", 1480 rp_cmd_args[header_type].name, header_type, header_len, 1481 (size_t)rp_cmd_args[header_type].len); 1482 mark_source_rp_bad(ms); 1483 goto out; 1484 } 1485 1486 /* We know we've got a valid header by this point */ 1487 res = qemu_get_buffer(rp, buf, header_len); 1488 if (res != header_len) { 1489 error_report("RP: Failed reading data for message 0x%04x" 1490 " read %d expected %d", 1491 header_type, res, header_len); 1492 mark_source_rp_bad(ms); 1493 goto out; 1494 } 1495 1496 /* OK, we have the message and the data */ 1497 switch (header_type) { 1498 case MIG_RP_MSG_SHUT: 1499 sibling_error = ldl_be_p(buf); 1500 trace_source_return_path_thread_shut(sibling_error); 1501 if (sibling_error) { 1502 error_report("RP: Sibling indicated error %d", sibling_error); 1503 mark_source_rp_bad(ms); 1504 } 1505 /* 1506 * We'll let the main thread deal with closing the RP 1507 * we could do a shutdown(2) on it, but we're the only user 1508 * anyway, so there's nothing gained. 1509 */ 1510 goto out; 1511 1512 case MIG_RP_MSG_PONG: 1513 tmp32 = ldl_be_p(buf); 1514 trace_source_return_path_thread_pong(tmp32); 1515 break; 1516 1517 case MIG_RP_MSG_REQ_PAGES: 1518 start = ldq_be_p(buf); 1519 len = ldl_be_p(buf + 8); 1520 migrate_handle_rp_req_pages(ms, NULL, start, len); 1521 break; 1522 1523 case MIG_RP_MSG_REQ_PAGES_ID: 1524 expected_len = 12 + 1; /* header + termination */ 1525 1526 if (header_len >= expected_len) { 1527 start = ldq_be_p(buf); 1528 len = ldl_be_p(buf + 8); 1529 /* Now we expect an idstr */ 1530 tmp32 = buf[12]; /* Length of the following idstr */ 1531 buf[13 + tmp32] = '\0'; 1532 expected_len += tmp32; 1533 } 1534 if (header_len != expected_len) { 1535 error_report("RP: Req_Page_id with length %d expecting %zd", 1536 header_len, expected_len); 1537 mark_source_rp_bad(ms); 1538 goto out; 1539 } 1540 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); 1541 break; 1542 1543 default: 1544 break; 1545 } 1546 } 1547 if (qemu_file_get_error(rp)) { 1548 trace_source_return_path_thread_bad_end(); 1549 mark_source_rp_bad(ms); 1550 } 1551 1552 trace_source_return_path_thread_end(); 1553 out: 1554 ms->rp_state.from_dst_file = NULL; 1555 qemu_fclose(rp); 1556 return NULL; 1557 } 1558 1559 static int open_return_path_on_source(MigrationState *ms) 1560 { 1561 1562 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); 1563 if (!ms->rp_state.from_dst_file) { 1564 return -1; 1565 } 1566 1567 trace_open_return_path_on_source(); 1568 qemu_thread_create(&ms->rp_state.rp_thread, "return path", 1569 source_return_path_thread, ms, QEMU_THREAD_JOINABLE); 1570 1571 trace_open_return_path_on_source_continue(); 1572 1573 return 0; 1574 } 1575 1576 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */ 1577 static int await_return_path_close_on_source(MigrationState *ms) 1578 { 1579 /* 1580 * If this is a normal exit then the destination will send a SHUT and the 1581 * rp_thread will exit, however if there's an error we need to cause 1582 * it to exit. 1583 */ 1584 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) { 1585 /* 1586 * shutdown(2), if we have it, will cause it to unblock if it's stuck 1587 * waiting for the destination. 1588 */ 1589 qemu_file_shutdown(ms->rp_state.from_dst_file); 1590 mark_source_rp_bad(ms); 1591 } 1592 trace_await_return_path_close_on_source_joining(); 1593 qemu_thread_join(&ms->rp_state.rp_thread); 1594 trace_await_return_path_close_on_source_close(); 1595 return ms->rp_state.error; 1596 } 1597 1598 /* 1599 * Switch from normal iteration to postcopy 1600 * Returns non-0 on error 1601 */ 1602 static int postcopy_start(MigrationState *ms, bool *old_vm_running) 1603 { 1604 int ret; 1605 QIOChannelBuffer *bioc; 1606 QEMUFile *fb; 1607 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1608 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE, 1609 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1610 1611 trace_postcopy_start(); 1612 qemu_mutex_lock_iothread(); 1613 trace_postcopy_start_set_run(); 1614 1615 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1616 *old_vm_running = runstate_is_running(); 1617 global_state_store(); 1618 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1619 if (ret < 0) { 1620 goto fail; 1621 } 1622 1623 ret = bdrv_inactivate_all(); 1624 if (ret < 0) { 1625 goto fail; 1626 } 1627 1628 /* 1629 * Cause any non-postcopiable, but iterative devices to 1630 * send out their final data. 1631 */ 1632 qemu_savevm_state_complete_precopy(ms->to_dst_file, true); 1633 1634 /* 1635 * in Finish migrate and with the io-lock held everything should 1636 * be quiet, but we've potentially still got dirty pages and we 1637 * need to tell the destination to throw any pages it's already received 1638 * that are dirty 1639 */ 1640 if (ram_postcopy_send_discard_bitmap(ms)) { 1641 error_report("postcopy send discard bitmap failed"); 1642 goto fail; 1643 } 1644 1645 /* 1646 * send rest of state - note things that are doing postcopy 1647 * will notice we're in POSTCOPY_ACTIVE and not actually 1648 * wrap their state up here 1649 */ 1650 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); 1651 /* Ping just for debugging, helps line traces up */ 1652 qemu_savevm_send_ping(ms->to_dst_file, 2); 1653 1654 /* 1655 * While loading the device state we may trigger page transfer 1656 * requests and the fd must be free to process those, and thus 1657 * the destination must read the whole device state off the fd before 1658 * it starts processing it. Unfortunately the ad-hoc migration format 1659 * doesn't allow the destination to know the size to read without fully 1660 * parsing it through each devices load-state code (especially the open 1661 * coded devices that use get/put). 1662 * So we wrap the device state up in a package with a length at the start; 1663 * to do this we use a qemu_buf to hold the whole of the device state. 1664 */ 1665 bioc = qio_channel_buffer_new(4096); 1666 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer"); 1667 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 1668 object_unref(OBJECT(bioc)); 1669 1670 /* 1671 * Make sure the receiver can get incoming pages before we send the rest 1672 * of the state 1673 */ 1674 qemu_savevm_send_postcopy_listen(fb); 1675 1676 qemu_savevm_state_complete_precopy(fb, false); 1677 qemu_savevm_send_ping(fb, 3); 1678 1679 qemu_savevm_send_postcopy_run(fb); 1680 1681 /* <><> end of stuff going into the package */ 1682 1683 /* Now send that blob */ 1684 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) { 1685 goto fail_closefb; 1686 } 1687 qemu_fclose(fb); 1688 1689 /* Send a notify to give a chance for anything that needs to happen 1690 * at the transition to postcopy and after the device state; in particular 1691 * spice needs to trigger a transition now 1692 */ 1693 ms->postcopy_after_devices = true; 1694 notifier_list_notify(&migration_state_notifiers, ms); 1695 1696 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop; 1697 1698 qemu_mutex_unlock_iothread(); 1699 1700 /* 1701 * Although this ping is just for debug, it could potentially be 1702 * used for getting a better measurement of downtime at the source. 1703 */ 1704 qemu_savevm_send_ping(ms->to_dst_file, 4); 1705 1706 ret = qemu_file_get_error(ms->to_dst_file); 1707 if (ret) { 1708 error_report("postcopy_start: Migration stream errored"); 1709 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1710 MIGRATION_STATUS_FAILED); 1711 } 1712 1713 return ret; 1714 1715 fail_closefb: 1716 qemu_fclose(fb); 1717 fail: 1718 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1719 MIGRATION_STATUS_FAILED); 1720 qemu_mutex_unlock_iothread(); 1721 return -1; 1722 } 1723 1724 /** 1725 * migration_completion: Used by migration_thread when there's not much left. 1726 * The caller 'breaks' the loop when this returns. 1727 * 1728 * @s: Current migration state 1729 * @current_active_state: The migration state we expect to be in 1730 * @*old_vm_running: Pointer to old_vm_running flag 1731 * @*start_time: Pointer to time to update 1732 */ 1733 static void migration_completion(MigrationState *s, int current_active_state, 1734 bool *old_vm_running, 1735 int64_t *start_time) 1736 { 1737 int ret; 1738 1739 if (s->state == MIGRATION_STATUS_ACTIVE) { 1740 qemu_mutex_lock_iothread(); 1741 *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1742 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1743 *old_vm_running = runstate_is_running(); 1744 ret = global_state_store(); 1745 1746 if (!ret) { 1747 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1748 /* 1749 * Don't mark the image with BDRV_O_INACTIVE flag if 1750 * we will go into COLO stage later. 1751 */ 1752 if (ret >= 0 && !migrate_colo_enabled()) { 1753 ret = bdrv_inactivate_all(); 1754 } 1755 if (ret >= 0) { 1756 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX); 1757 qemu_savevm_state_complete_precopy(s->to_dst_file, false); 1758 s->block_inactive = true; 1759 } 1760 } 1761 qemu_mutex_unlock_iothread(); 1762 1763 if (ret < 0) { 1764 goto fail; 1765 } 1766 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1767 trace_migration_completion_postcopy_end(); 1768 1769 qemu_savevm_state_complete_postcopy(s->to_dst_file); 1770 trace_migration_completion_postcopy_end_after_complete(); 1771 } 1772 1773 /* 1774 * If rp was opened we must clean up the thread before 1775 * cleaning everything else up (since if there are no failures 1776 * it will wait for the destination to send it's status in 1777 * a SHUT command). 1778 * Postcopy opens rp if enabled (even if it's not avtivated) 1779 */ 1780 if (migrate_postcopy_ram()) { 1781 int rp_error; 1782 trace_migration_completion_postcopy_end_before_rp(); 1783 rp_error = await_return_path_close_on_source(s); 1784 trace_migration_completion_postcopy_end_after_rp(rp_error); 1785 if (rp_error) { 1786 goto fail_invalidate; 1787 } 1788 } 1789 1790 if (qemu_file_get_error(s->to_dst_file)) { 1791 trace_migration_completion_file_err(); 1792 goto fail_invalidate; 1793 } 1794 1795 if (!migrate_colo_enabled()) { 1796 migrate_set_state(&s->state, current_active_state, 1797 MIGRATION_STATUS_COMPLETED); 1798 } 1799 1800 return; 1801 1802 fail_invalidate: 1803 /* If not doing postcopy, vm_start() will be called: let's regain 1804 * control on images. 1805 */ 1806 if (s->state == MIGRATION_STATUS_ACTIVE) { 1807 Error *local_err = NULL; 1808 1809 qemu_mutex_lock_iothread(); 1810 bdrv_invalidate_cache_all(&local_err); 1811 if (local_err) { 1812 error_report_err(local_err); 1813 } else { 1814 s->block_inactive = false; 1815 } 1816 qemu_mutex_unlock_iothread(); 1817 } 1818 1819 fail: 1820 migrate_set_state(&s->state, current_active_state, 1821 MIGRATION_STATUS_FAILED); 1822 } 1823 1824 bool migrate_colo_enabled(void) 1825 { 1826 MigrationState *s = migrate_get_current(); 1827 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO]; 1828 } 1829 1830 /* 1831 * Master migration thread on the source VM. 1832 * It drives the migration and pumps the data down the outgoing channel. 1833 */ 1834 static void *migration_thread(void *opaque) 1835 { 1836 MigrationState *s = opaque; 1837 /* Used by the bandwidth calcs, updated later */ 1838 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1839 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); 1840 int64_t initial_bytes = 0; 1841 int64_t max_size = 0; 1842 int64_t start_time = initial_time; 1843 int64_t end_time; 1844 bool old_vm_running = false; 1845 bool entered_postcopy = false; 1846 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */ 1847 enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE; 1848 bool enable_colo = migrate_colo_enabled(); 1849 1850 rcu_register_thread(); 1851 1852 qemu_savevm_state_header(s->to_dst_file); 1853 1854 if (migrate_postcopy_ram()) { 1855 /* Now tell the dest that it should open its end so it can reply */ 1856 qemu_savevm_send_open_return_path(s->to_dst_file); 1857 1858 /* And do a ping that will make stuff easier to debug */ 1859 qemu_savevm_send_ping(s->to_dst_file, 1); 1860 1861 /* 1862 * Tell the destination that we *might* want to do postcopy later; 1863 * if the other end can't do postcopy it should fail now, nice and 1864 * early. 1865 */ 1866 qemu_savevm_send_postcopy_advise(s->to_dst_file); 1867 } 1868 1869 qemu_savevm_state_begin(s->to_dst_file, &s->params); 1870 1871 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; 1872 current_active_state = MIGRATION_STATUS_ACTIVE; 1873 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1874 MIGRATION_STATUS_ACTIVE); 1875 1876 trace_migration_thread_setup_complete(); 1877 1878 while (s->state == MIGRATION_STATUS_ACTIVE || 1879 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1880 int64_t current_time; 1881 uint64_t pending_size; 1882 1883 if (!qemu_file_rate_limit(s->to_dst_file)) { 1884 uint64_t pend_post, pend_nonpost; 1885 1886 qemu_savevm_state_pending(s->to_dst_file, max_size, &pend_nonpost, 1887 &pend_post); 1888 pending_size = pend_nonpost + pend_post; 1889 trace_migrate_pending(pending_size, max_size, 1890 pend_post, pend_nonpost); 1891 if (pending_size && pending_size >= max_size) { 1892 /* Still a significant amount to transfer */ 1893 1894 if (migrate_postcopy_ram() && 1895 s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE && 1896 pend_nonpost <= max_size && 1897 atomic_read(&s->start_postcopy)) { 1898 1899 if (!postcopy_start(s, &old_vm_running)) { 1900 current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE; 1901 entered_postcopy = true; 1902 } 1903 1904 continue; 1905 } 1906 /* Just another iteration step */ 1907 qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy); 1908 } else { 1909 trace_migration_thread_low_pending(pending_size); 1910 migration_completion(s, current_active_state, 1911 &old_vm_running, &start_time); 1912 break; 1913 } 1914 } 1915 1916 if (qemu_file_get_error(s->to_dst_file)) { 1917 migrate_set_state(&s->state, current_active_state, 1918 MIGRATION_STATUS_FAILED); 1919 trace_migration_thread_file_err(); 1920 break; 1921 } 1922 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1923 if (current_time >= initial_time + BUFFER_DELAY) { 1924 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file) - 1925 initial_bytes; 1926 uint64_t time_spent = current_time - initial_time; 1927 double bandwidth = (double)transferred_bytes / time_spent; 1928 max_size = bandwidth * s->parameters.downtime_limit; 1929 1930 s->mbps = (((double) transferred_bytes * 8.0) / 1931 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; 1932 1933 trace_migrate_transferred(transferred_bytes, time_spent, 1934 bandwidth, max_size); 1935 /* if we haven't sent anything, we don't want to recalculate 1936 10000 is a small enough number for our purposes */ 1937 if (s->dirty_bytes_rate && transferred_bytes > 10000) { 1938 s->expected_downtime = s->dirty_bytes_rate / bandwidth; 1939 } 1940 1941 qemu_file_reset_rate_limit(s->to_dst_file); 1942 initial_time = current_time; 1943 initial_bytes = qemu_ftell(s->to_dst_file); 1944 } 1945 if (qemu_file_rate_limit(s->to_dst_file)) { 1946 /* usleep expects microseconds */ 1947 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); 1948 } 1949 } 1950 1951 trace_migration_thread_after_loop(); 1952 /* If we enabled cpu throttling for auto-converge, turn it off. */ 1953 cpu_throttle_stop(); 1954 end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1955 1956 qemu_mutex_lock_iothread(); 1957 /* 1958 * The resource has been allocated by migration will be reused in COLO 1959 * process, so don't release them. 1960 */ 1961 if (!enable_colo) { 1962 qemu_savevm_state_cleanup(); 1963 } 1964 if (s->state == MIGRATION_STATUS_COMPLETED) { 1965 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file); 1966 s->total_time = end_time - s->total_time; 1967 if (!entered_postcopy) { 1968 s->downtime = end_time - start_time; 1969 } 1970 if (s->total_time) { 1971 s->mbps = (((double) transferred_bytes * 8.0) / 1972 ((double) s->total_time)) / 1000; 1973 } 1974 runstate_set(RUN_STATE_POSTMIGRATE); 1975 } else { 1976 if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) { 1977 migrate_start_colo_process(s); 1978 qemu_savevm_state_cleanup(); 1979 /* 1980 * Fixme: we will run VM in COLO no matter its old running state. 1981 * After exited COLO, we will keep running. 1982 */ 1983 old_vm_running = true; 1984 } 1985 if (old_vm_running && !entered_postcopy) { 1986 vm_start(); 1987 } else { 1988 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) { 1989 runstate_set(RUN_STATE_POSTMIGRATE); 1990 } 1991 } 1992 } 1993 qemu_bh_schedule(s->cleanup_bh); 1994 qemu_mutex_unlock_iothread(); 1995 1996 rcu_unregister_thread(); 1997 return NULL; 1998 } 1999 2000 void migrate_fd_connect(MigrationState *s) 2001 { 2002 s->expected_downtime = s->parameters.downtime_limit; 2003 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); 2004 2005 qemu_file_set_blocking(s->to_dst_file, true); 2006 qemu_file_set_rate_limit(s->to_dst_file, 2007 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 2008 2009 /* Notify before starting migration thread */ 2010 notifier_list_notify(&migration_state_notifiers, s); 2011 2012 /* 2013 * Open the return path; currently for postcopy but other things might 2014 * also want it. 2015 */ 2016 if (migrate_postcopy_ram()) { 2017 if (open_return_path_on_source(s)) { 2018 error_report("Unable to open return-path for postcopy"); 2019 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 2020 MIGRATION_STATUS_FAILED); 2021 migrate_fd_cleanup(s); 2022 return; 2023 } 2024 } 2025 2026 migrate_compress_threads_create(); 2027 qemu_thread_create(&s->thread, "live_migration", migration_thread, s, 2028 QEMU_THREAD_JOINABLE); 2029 s->migration_thread_running = true; 2030 } 2031 2032 PostcopyState postcopy_state_get(void) 2033 { 2034 return atomic_mb_read(&incoming_postcopy_state); 2035 } 2036 2037 /* Set the state and return the old state */ 2038 PostcopyState postcopy_state_set(PostcopyState new_state) 2039 { 2040 return atomic_xchg(&incoming_postcopy_state, new_state); 2041 } 2042 2043