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/qmp/qerror.h" 34 #include "qapi/util.h" 35 #include "qemu/rcu.h" 36 #include "block.h" 37 #include "postcopy-ram.h" 38 #include "qemu/thread.h" 39 #include "qmp-commands.h" 40 #include "trace.h" 41 #include "qapi-event.h" 42 #include "exec/target_page.h" 43 #include "io/channel-buffer.h" 44 #include "migration/colo.h" 45 46 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ 47 48 /* Amount of time to allocate to each "chunk" of bandwidth-throttled 49 * data. */ 50 #define BUFFER_DELAY 100 51 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) 52 53 /* Time in milliseconds we are allowed to stop the source, 54 * for sending the last part */ 55 #define DEFAULT_MIGRATE_SET_DOWNTIME 300 56 57 /* Maximum migrate downtime set to 2000 seconds */ 58 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000 59 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000) 60 61 /* Default compression thread count */ 62 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8 63 /* Default decompression thread count, usually decompression is at 64 * least 4 times as fast as compression.*/ 65 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2 66 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */ 67 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1 68 /* Define default autoconverge cpu throttle migration parameters */ 69 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20 70 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10 71 72 /* Migration XBZRLE default cache size */ 73 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) 74 75 /* The delay time (in ms) between two COLO checkpoints 76 * Note: Please change this default value to 10000 when we support hybrid mode. 77 */ 78 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200 79 80 static NotifierList migration_state_notifiers = 81 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); 82 83 static bool deferred_incoming; 84 85 /* Messages sent on the return path from destination to source */ 86 enum mig_rp_message_type { 87 MIG_RP_MSG_INVALID = 0, /* Must be 0 */ 88 MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */ 89 MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */ 90 91 MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */ 92 MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */ 93 94 MIG_RP_MSG_MAX 95 }; 96 97 /* When we add fault tolerance, we could have several 98 migrations at once. For now we don't need to add 99 dynamic creation of migration */ 100 101 /* For outgoing */ 102 MigrationState *migrate_get_current(void) 103 { 104 static bool once; 105 static MigrationState current_migration = { 106 .state = MIGRATION_STATUS_NONE, 107 .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE, 108 .mbps = -1, 109 .parameters = { 110 .compress_level = DEFAULT_MIGRATE_COMPRESS_LEVEL, 111 .compress_threads = DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT, 112 .decompress_threads = DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT, 113 .cpu_throttle_initial = DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL, 114 .cpu_throttle_increment = DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT, 115 .max_bandwidth = MAX_THROTTLE, 116 .downtime_limit = DEFAULT_MIGRATE_SET_DOWNTIME, 117 .x_checkpoint_delay = DEFAULT_MIGRATE_X_CHECKPOINT_DELAY, 118 }, 119 }; 120 121 if (!once) { 122 current_migration.parameters.tls_creds = g_strdup(""); 123 current_migration.parameters.tls_hostname = g_strdup(""); 124 once = true; 125 } 126 return ¤t_migration; 127 } 128 129 MigrationIncomingState *migration_incoming_get_current(void) 130 { 131 static bool once; 132 static MigrationIncomingState mis_current; 133 134 if (!once) { 135 mis_current.state = MIGRATION_STATUS_NONE; 136 memset(&mis_current, 0, sizeof(MigrationIncomingState)); 137 qemu_mutex_init(&mis_current.rp_mutex); 138 qemu_event_init(&mis_current.main_thread_load_event, false); 139 once = true; 140 } 141 return &mis_current; 142 } 143 144 void migration_incoming_state_destroy(void) 145 { 146 struct MigrationIncomingState *mis = migration_incoming_get_current(); 147 148 if (mis->to_src_file) { 149 /* Tell source that we are done */ 150 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0); 151 qemu_fclose(mis->to_src_file); 152 mis->to_src_file = NULL; 153 } 154 155 if (mis->from_src_file) { 156 qemu_fclose(mis->from_src_file); 157 mis->from_src_file = NULL; 158 } 159 160 qemu_event_destroy(&mis->main_thread_load_event); 161 } 162 163 static void migrate_generate_event(int new_state) 164 { 165 if (migrate_use_events()) { 166 qapi_event_send_migration(new_state, &error_abort); 167 } 168 } 169 170 /* 171 * Called on -incoming with a defer: uri. 172 * The migration can be started later after any parameters have been 173 * changed. 174 */ 175 static void deferred_incoming_migration(Error **errp) 176 { 177 if (deferred_incoming) { 178 error_setg(errp, "Incoming migration already deferred"); 179 } 180 deferred_incoming = true; 181 } 182 183 /* 184 * Send a message on the return channel back to the source 185 * of the migration. 186 */ 187 static void migrate_send_rp_message(MigrationIncomingState *mis, 188 enum mig_rp_message_type message_type, 189 uint16_t len, void *data) 190 { 191 trace_migrate_send_rp_message((int)message_type, len); 192 qemu_mutex_lock(&mis->rp_mutex); 193 qemu_put_be16(mis->to_src_file, (unsigned int)message_type); 194 qemu_put_be16(mis->to_src_file, len); 195 qemu_put_buffer(mis->to_src_file, data, len); 196 qemu_fflush(mis->to_src_file); 197 qemu_mutex_unlock(&mis->rp_mutex); 198 } 199 200 /* Request a range of pages from the source VM at the given 201 * start address. 202 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same 203 * as the last request (a name must have been given previously) 204 * Start: Address offset within the RB 205 * Len: Length in bytes required - must be a multiple of pagesize 206 */ 207 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, 208 ram_addr_t start, size_t len) 209 { 210 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */ 211 size_t msglen = 12; /* start + len */ 212 213 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); 214 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); 215 216 if (rbname) { 217 int rbname_len = strlen(rbname); 218 assert(rbname_len < 256); 219 220 bufc[msglen++] = rbname_len; 221 memcpy(bufc + msglen, rbname, rbname_len); 222 msglen += rbname_len; 223 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc); 224 } else { 225 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc); 226 } 227 } 228 229 void qemu_start_incoming_migration(const char *uri, Error **errp) 230 { 231 const char *p; 232 233 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort); 234 if (!strcmp(uri, "defer")) { 235 deferred_incoming_migration(errp); 236 } else if (strstart(uri, "tcp:", &p)) { 237 tcp_start_incoming_migration(p, errp); 238 #ifdef CONFIG_RDMA 239 } else if (strstart(uri, "rdma:", &p)) { 240 rdma_start_incoming_migration(p, errp); 241 #endif 242 } else if (strstart(uri, "exec:", &p)) { 243 exec_start_incoming_migration(p, errp); 244 } else if (strstart(uri, "unix:", &p)) { 245 unix_start_incoming_migration(p, errp); 246 } else if (strstart(uri, "fd:", &p)) { 247 fd_start_incoming_migration(p, errp); 248 } else { 249 error_setg(errp, "unknown migration protocol: %s", uri); 250 } 251 } 252 253 static void process_incoming_migration_bh(void *opaque) 254 { 255 Error *local_err = NULL; 256 MigrationIncomingState *mis = opaque; 257 258 /* Make sure all file formats flush their mutable metadata. 259 * If we get an error here, just don't restart the VM yet. */ 260 bdrv_invalidate_cache_all(&local_err); 261 if (local_err) { 262 error_report_err(local_err); 263 local_err = NULL; 264 autostart = false; 265 } 266 267 /* 268 * This must happen after all error conditions are dealt with and 269 * we're sure the VM is going to be running on this host. 270 */ 271 qemu_announce_self(); 272 273 /* If global state section was not received or we are in running 274 state, we need to obey autostart. Any other state is set with 275 runstate_set. */ 276 277 if (!global_state_received() || 278 global_state_get_runstate() == RUN_STATE_RUNNING) { 279 if (autostart) { 280 vm_start(); 281 } else { 282 runstate_set(RUN_STATE_PAUSED); 283 } 284 } else { 285 runstate_set(global_state_get_runstate()); 286 } 287 migrate_decompress_threads_join(); 288 /* 289 * This must happen after any state changes since as soon as an external 290 * observer sees this event they might start to prod at the VM assuming 291 * it's ready to use. 292 */ 293 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 294 MIGRATION_STATUS_COMPLETED); 295 qemu_bh_delete(mis->bh); 296 migration_incoming_state_destroy(); 297 } 298 299 static void process_incoming_migration_co(void *opaque) 300 { 301 QEMUFile *f = opaque; 302 MigrationIncomingState *mis = migration_incoming_get_current(); 303 PostcopyState ps; 304 int ret; 305 306 mis->from_src_file = f; 307 mis->largest_page_size = qemu_ram_pagesize_largest(); 308 postcopy_state_set(POSTCOPY_INCOMING_NONE); 309 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE, 310 MIGRATION_STATUS_ACTIVE); 311 ret = qemu_loadvm_state(f); 312 313 ps = postcopy_state_get(); 314 trace_process_incoming_migration_co_end(ret, ps); 315 if (ps != POSTCOPY_INCOMING_NONE) { 316 if (ps == POSTCOPY_INCOMING_ADVISE) { 317 /* 318 * Where a migration had postcopy enabled (and thus went to advise) 319 * but managed to complete within the precopy period, we can use 320 * the normal exit. 321 */ 322 postcopy_ram_incoming_cleanup(mis); 323 } else if (ret >= 0) { 324 /* 325 * Postcopy was started, cleanup should happen at the end of the 326 * postcopy thread. 327 */ 328 trace_process_incoming_migration_co_postcopy_end_main(); 329 return; 330 } 331 /* Else if something went wrong then just fall out of the normal exit */ 332 } 333 334 /* we get COLO info, and know if we are in COLO mode */ 335 if (!ret && migration_incoming_enable_colo()) { 336 mis->migration_incoming_co = qemu_coroutine_self(); 337 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming", 338 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE); 339 mis->have_colo_incoming_thread = true; 340 qemu_coroutine_yield(); 341 342 /* Wait checkpoint incoming thread exit before free resource */ 343 qemu_thread_join(&mis->colo_incoming_thread); 344 } 345 346 if (ret < 0) { 347 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 348 MIGRATION_STATUS_FAILED); 349 error_report("load of migration failed: %s", strerror(-ret)); 350 migrate_decompress_threads_join(); 351 exit(EXIT_FAILURE); 352 } 353 354 free_xbzrle_decoded_buf(); 355 356 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); 357 qemu_bh_schedule(mis->bh); 358 } 359 360 void migration_fd_process_incoming(QEMUFile *f) 361 { 362 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, f); 363 364 migrate_decompress_threads_create(); 365 qemu_file_set_blocking(f, false); 366 qemu_coroutine_enter(co); 367 } 368 369 /* 370 * Send a 'SHUT' message on the return channel with the given value 371 * to indicate that we've finished with the RP. Non-0 value indicates 372 * error. 373 */ 374 void migrate_send_rp_shut(MigrationIncomingState *mis, 375 uint32_t value) 376 { 377 uint32_t buf; 378 379 buf = cpu_to_be32(value); 380 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); 381 } 382 383 /* 384 * Send a 'PONG' message on the return channel with the given value 385 * (normally in response to a 'PING') 386 */ 387 void migrate_send_rp_pong(MigrationIncomingState *mis, 388 uint32_t value) 389 { 390 uint32_t buf; 391 392 buf = cpu_to_be32(value); 393 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); 394 } 395 396 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) 397 { 398 MigrationCapabilityStatusList *head = NULL; 399 MigrationCapabilityStatusList *caps; 400 MigrationState *s = migrate_get_current(); 401 int i; 402 403 caps = NULL; /* silence compiler warning */ 404 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 405 #ifndef CONFIG_LIVE_BLOCK_MIGRATION 406 if (i == MIGRATION_CAPABILITY_BLOCK) { 407 continue; 408 } 409 #endif 410 if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) { 411 continue; 412 } 413 if (head == NULL) { 414 head = g_malloc0(sizeof(*caps)); 415 caps = head; 416 } else { 417 caps->next = g_malloc0(sizeof(*caps)); 418 caps = caps->next; 419 } 420 caps->value = 421 g_malloc(sizeof(*caps->value)); 422 caps->value->capability = i; 423 caps->value->state = s->enabled_capabilities[i]; 424 } 425 426 return head; 427 } 428 429 MigrationParameters *qmp_query_migrate_parameters(Error **errp) 430 { 431 MigrationParameters *params; 432 MigrationState *s = migrate_get_current(); 433 434 params = g_malloc0(sizeof(*params)); 435 params->has_compress_level = true; 436 params->compress_level = s->parameters.compress_level; 437 params->has_compress_threads = true; 438 params->compress_threads = s->parameters.compress_threads; 439 params->has_decompress_threads = true; 440 params->decompress_threads = s->parameters.decompress_threads; 441 params->has_cpu_throttle_initial = true; 442 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; 443 params->has_cpu_throttle_increment = true; 444 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; 445 params->has_tls_creds = !!s->parameters.tls_creds; 446 params->tls_creds = g_strdup(s->parameters.tls_creds); 447 params->has_tls_hostname = !!s->parameters.tls_hostname; 448 params->tls_hostname = g_strdup(s->parameters.tls_hostname); 449 params->has_max_bandwidth = true; 450 params->max_bandwidth = s->parameters.max_bandwidth; 451 params->has_downtime_limit = true; 452 params->downtime_limit = s->parameters.downtime_limit; 453 params->has_x_checkpoint_delay = true; 454 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay; 455 params->has_block_incremental = true; 456 params->block_incremental = s->parameters.block_incremental; 457 458 return params; 459 } 460 461 /* 462 * Return true if we're already in the middle of a migration 463 * (i.e. any of the active or setup states) 464 */ 465 static bool migration_is_setup_or_active(int state) 466 { 467 switch (state) { 468 case MIGRATION_STATUS_ACTIVE: 469 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 470 case MIGRATION_STATUS_SETUP: 471 return true; 472 473 default: 474 return false; 475 476 } 477 } 478 479 static void populate_ram_info(MigrationInfo *info, MigrationState *s) 480 { 481 info->has_ram = true; 482 info->ram = g_malloc0(sizeof(*info->ram)); 483 info->ram->transferred = ram_counters.transferred; 484 info->ram->total = ram_bytes_total(); 485 info->ram->duplicate = ram_counters.duplicate; 486 /* legacy value. It is not used anymore */ 487 info->ram->skipped = 0; 488 info->ram->normal = ram_counters.normal; 489 info->ram->normal_bytes = ram_counters.normal * 490 qemu_target_page_size(); 491 info->ram->mbps = s->mbps; 492 info->ram->dirty_sync_count = ram_counters.dirty_sync_count; 493 info->ram->postcopy_requests = ram_counters.postcopy_requests; 494 info->ram->page_size = qemu_target_page_size(); 495 496 if (migrate_use_xbzrle()) { 497 info->has_xbzrle_cache = true; 498 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); 499 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); 500 info->xbzrle_cache->bytes = xbzrle_counters.bytes; 501 info->xbzrle_cache->pages = xbzrle_counters.pages; 502 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss; 503 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate; 504 info->xbzrle_cache->overflow = xbzrle_counters.overflow; 505 } 506 507 if (cpu_throttle_active()) { 508 info->has_cpu_throttle_percentage = true; 509 info->cpu_throttle_percentage = cpu_throttle_get_percentage(); 510 } 511 512 if (s->state != MIGRATION_STATUS_COMPLETED) { 513 info->ram->remaining = ram_bytes_remaining(); 514 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate; 515 } 516 } 517 518 static void populate_disk_info(MigrationInfo *info) 519 { 520 if (blk_mig_active()) { 521 info->has_disk = true; 522 info->disk = g_malloc0(sizeof(*info->disk)); 523 info->disk->transferred = blk_mig_bytes_transferred(); 524 info->disk->remaining = blk_mig_bytes_remaining(); 525 info->disk->total = blk_mig_bytes_total(); 526 } 527 } 528 529 MigrationInfo *qmp_query_migrate(Error **errp) 530 { 531 MigrationInfo *info = g_malloc0(sizeof(*info)); 532 MigrationState *s = migrate_get_current(); 533 534 switch (s->state) { 535 case MIGRATION_STATUS_NONE: 536 /* no migration has happened ever */ 537 break; 538 case MIGRATION_STATUS_SETUP: 539 info->has_status = true; 540 info->has_total_time = false; 541 break; 542 case MIGRATION_STATUS_ACTIVE: 543 case MIGRATION_STATUS_CANCELLING: 544 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 545 /* TODO add some postcopy stats */ 546 info->has_status = true; 547 info->has_total_time = true; 548 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 549 - s->total_time; 550 info->has_expected_downtime = true; 551 info->expected_downtime = s->expected_downtime; 552 info->has_setup_time = true; 553 info->setup_time = s->setup_time; 554 555 populate_ram_info(info, s); 556 populate_disk_info(info); 557 break; 558 case MIGRATION_STATUS_COLO: 559 info->has_status = true; 560 /* TODO: display COLO specific information (checkpoint info etc.) */ 561 break; 562 case MIGRATION_STATUS_COMPLETED: 563 info->has_status = true; 564 info->has_total_time = true; 565 info->total_time = s->total_time; 566 info->has_downtime = true; 567 info->downtime = s->downtime; 568 info->has_setup_time = true; 569 info->setup_time = s->setup_time; 570 571 populate_ram_info(info, s); 572 break; 573 case MIGRATION_STATUS_FAILED: 574 info->has_status = true; 575 if (s->error) { 576 info->has_error_desc = true; 577 info->error_desc = g_strdup(error_get_pretty(s->error)); 578 } 579 break; 580 case MIGRATION_STATUS_CANCELLED: 581 info->has_status = true; 582 break; 583 } 584 info->status = s->state; 585 586 return info; 587 } 588 589 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 590 Error **errp) 591 { 592 MigrationState *s = migrate_get_current(); 593 MigrationCapabilityStatusList *cap; 594 bool old_postcopy_cap = migrate_postcopy_ram(); 595 596 if (migration_is_setup_or_active(s->state)) { 597 error_setg(errp, QERR_MIGRATION_ACTIVE); 598 return; 599 } 600 601 for (cap = params; cap; cap = cap->next) { 602 #ifndef CONFIG_LIVE_BLOCK_MIGRATION 603 if (cap->value->capability == MIGRATION_CAPABILITY_BLOCK 604 && cap->value->state) { 605 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) " 606 "block migration"); 607 error_append_hint(errp, "Use drive_mirror+NBD instead.\n"); 608 continue; 609 } 610 #endif 611 if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) { 612 if (!colo_supported()) { 613 error_setg(errp, "COLO is not currently supported, please" 614 " configure with --enable-colo option in order to" 615 " support COLO feature"); 616 continue; 617 } 618 } 619 s->enabled_capabilities[cap->value->capability] = cap->value->state; 620 } 621 622 if (migrate_postcopy_ram()) { 623 if (migrate_use_compression()) { 624 /* The decompression threads asynchronously write into RAM 625 * rather than use the atomic copies needed to avoid 626 * userfaulting. It should be possible to fix the decompression 627 * threads for compatibility in future. 628 */ 629 error_report("Postcopy is not currently compatible with " 630 "compression"); 631 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] = 632 false; 633 } 634 /* This check is reasonably expensive, so only when it's being 635 * set the first time, also it's only the destination that needs 636 * special support. 637 */ 638 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) && 639 !postcopy_ram_supported_by_host()) { 640 /* postcopy_ram_supported_by_host will have emitted a more 641 * detailed message 642 */ 643 error_report("Postcopy is not supported"); 644 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] = 645 false; 646 } 647 } 648 } 649 650 void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp) 651 { 652 MigrationState *s = migrate_get_current(); 653 654 if (params->has_compress_level && 655 (params->compress_level < 0 || params->compress_level > 9)) { 656 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level", 657 "is invalid, it should be in the range of 0 to 9"); 658 return; 659 } 660 if (params->has_compress_threads && 661 (params->compress_threads < 1 || params->compress_threads > 255)) { 662 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 663 "compress_threads", 664 "is invalid, it should be in the range of 1 to 255"); 665 return; 666 } 667 if (params->has_decompress_threads && 668 (params->decompress_threads < 1 || params->decompress_threads > 255)) { 669 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 670 "decompress_threads", 671 "is invalid, it should be in the range of 1 to 255"); 672 return; 673 } 674 if (params->has_cpu_throttle_initial && 675 (params->cpu_throttle_initial < 1 || 676 params->cpu_throttle_initial > 99)) { 677 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 678 "cpu_throttle_initial", 679 "an integer in the range of 1 to 99"); 680 return; 681 } 682 if (params->has_cpu_throttle_increment && 683 (params->cpu_throttle_increment < 1 || 684 params->cpu_throttle_increment > 99)) { 685 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 686 "cpu_throttle_increment", 687 "an integer in the range of 1 to 99"); 688 return; 689 } 690 if (params->has_max_bandwidth && 691 (params->max_bandwidth < 0 || params->max_bandwidth > SIZE_MAX)) { 692 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the" 693 " range of 0 to %zu bytes/second", SIZE_MAX); 694 return; 695 } 696 if (params->has_downtime_limit && 697 (params->downtime_limit < 0 || 698 params->downtime_limit > MAX_MIGRATE_DOWNTIME)) { 699 error_setg(errp, "Parameter 'downtime_limit' expects an integer in " 700 "the range of 0 to %d milliseconds", 701 MAX_MIGRATE_DOWNTIME); 702 return; 703 } 704 if (params->has_x_checkpoint_delay && (params->x_checkpoint_delay < 0)) { 705 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 706 "x_checkpoint_delay", 707 "is invalid, it should be positive"); 708 } 709 710 if (params->has_compress_level) { 711 s->parameters.compress_level = params->compress_level; 712 } 713 if (params->has_compress_threads) { 714 s->parameters.compress_threads = params->compress_threads; 715 } 716 if (params->has_decompress_threads) { 717 s->parameters.decompress_threads = params->decompress_threads; 718 } 719 if (params->has_cpu_throttle_initial) { 720 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial; 721 } 722 if (params->has_cpu_throttle_increment) { 723 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; 724 } 725 if (params->has_tls_creds) { 726 g_free(s->parameters.tls_creds); 727 s->parameters.tls_creds = g_strdup(params->tls_creds); 728 } 729 if (params->has_tls_hostname) { 730 g_free(s->parameters.tls_hostname); 731 s->parameters.tls_hostname = g_strdup(params->tls_hostname); 732 } 733 if (params->has_max_bandwidth) { 734 s->parameters.max_bandwidth = params->max_bandwidth; 735 if (s->to_dst_file) { 736 qemu_file_set_rate_limit(s->to_dst_file, 737 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 738 } 739 } 740 if (params->has_downtime_limit) { 741 s->parameters.downtime_limit = params->downtime_limit; 742 } 743 744 if (params->has_x_checkpoint_delay) { 745 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay; 746 if (migration_in_colo_state()) { 747 colo_checkpoint_notify(s); 748 } 749 } 750 if (params->has_block_incremental) { 751 s->parameters.block_incremental = params->block_incremental; 752 } 753 } 754 755 756 void qmp_migrate_start_postcopy(Error **errp) 757 { 758 MigrationState *s = migrate_get_current(); 759 760 if (!migrate_postcopy_ram()) { 761 error_setg(errp, "Enable postcopy with migrate_set_capability before" 762 " the start of migration"); 763 return; 764 } 765 766 if (s->state == MIGRATION_STATUS_NONE) { 767 error_setg(errp, "Postcopy must be started after migration has been" 768 " started"); 769 return; 770 } 771 /* 772 * we don't error if migration has finished since that would be racy 773 * with issuing this command. 774 */ 775 atomic_set(&s->start_postcopy, true); 776 } 777 778 /* shared migration helpers */ 779 780 void migrate_set_state(int *state, int old_state, int new_state) 781 { 782 if (atomic_cmpxchg(state, old_state, new_state) == old_state) { 783 trace_migrate_set_state(new_state); 784 migrate_generate_event(new_state); 785 } 786 } 787 788 void migrate_set_block_enabled(bool value, Error **errp) 789 { 790 MigrationCapabilityStatusList *cap; 791 792 cap = g_new0(MigrationCapabilityStatusList, 1); 793 cap->value = g_new0(MigrationCapabilityStatus, 1); 794 cap->value->capability = MIGRATION_CAPABILITY_BLOCK; 795 cap->value->state = value; 796 qmp_migrate_set_capabilities(cap, errp); 797 qapi_free_MigrationCapabilityStatusList(cap); 798 } 799 800 static void migrate_set_block_incremental(MigrationState *s, bool value) 801 { 802 s->parameters.block_incremental = value; 803 } 804 805 static void block_cleanup_parameters(MigrationState *s) 806 { 807 if (s->must_remove_block_options) { 808 /* setting to false can never fail */ 809 migrate_set_block_enabled(false, &error_abort); 810 migrate_set_block_incremental(s, false); 811 s->must_remove_block_options = false; 812 } 813 } 814 815 static void migrate_fd_cleanup(void *opaque) 816 { 817 MigrationState *s = opaque; 818 819 qemu_bh_delete(s->cleanup_bh); 820 s->cleanup_bh = NULL; 821 822 if (s->to_dst_file) { 823 trace_migrate_fd_cleanup(); 824 qemu_mutex_unlock_iothread(); 825 if (s->migration_thread_running) { 826 qemu_thread_join(&s->thread); 827 s->migration_thread_running = false; 828 } 829 qemu_mutex_lock_iothread(); 830 831 migrate_compress_threads_join(); 832 qemu_fclose(s->to_dst_file); 833 s->to_dst_file = NULL; 834 } 835 836 assert((s->state != MIGRATION_STATUS_ACTIVE) && 837 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE)); 838 839 if (s->state == MIGRATION_STATUS_CANCELLING) { 840 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING, 841 MIGRATION_STATUS_CANCELLED); 842 } 843 844 notifier_list_notify(&migration_state_notifiers, s); 845 block_cleanup_parameters(s); 846 } 847 848 void migrate_fd_error(MigrationState *s, const Error *error) 849 { 850 trace_migrate_fd_error(error_get_pretty(error)); 851 assert(s->to_dst_file == NULL); 852 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 853 MIGRATION_STATUS_FAILED); 854 if (!s->error) { 855 s->error = error_copy(error); 856 } 857 notifier_list_notify(&migration_state_notifiers, s); 858 block_cleanup_parameters(s); 859 } 860 861 static void migrate_fd_cancel(MigrationState *s) 862 { 863 int old_state ; 864 QEMUFile *f = migrate_get_current()->to_dst_file; 865 trace_migrate_fd_cancel(); 866 867 if (s->rp_state.from_dst_file) { 868 /* shutdown the rp socket, so causing the rp thread to shutdown */ 869 qemu_file_shutdown(s->rp_state.from_dst_file); 870 } 871 872 do { 873 old_state = s->state; 874 if (!migration_is_setup_or_active(old_state)) { 875 break; 876 } 877 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING); 878 } while (s->state != MIGRATION_STATUS_CANCELLING); 879 880 /* 881 * If we're unlucky the migration code might be stuck somewhere in a 882 * send/write while the network has failed and is waiting to timeout; 883 * if we've got shutdown(2) available then we can force it to quit. 884 * The outgoing qemu file gets closed in migrate_fd_cleanup that is 885 * called in a bh, so there is no race against this cancel. 886 */ 887 if (s->state == MIGRATION_STATUS_CANCELLING && f) { 888 qemu_file_shutdown(f); 889 } 890 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) { 891 Error *local_err = NULL; 892 893 bdrv_invalidate_cache_all(&local_err); 894 if (local_err) { 895 error_report_err(local_err); 896 } else { 897 s->block_inactive = false; 898 } 899 } 900 block_cleanup_parameters(s); 901 } 902 903 void add_migration_state_change_notifier(Notifier *notify) 904 { 905 notifier_list_add(&migration_state_notifiers, notify); 906 } 907 908 void remove_migration_state_change_notifier(Notifier *notify) 909 { 910 notifier_remove(notify); 911 } 912 913 bool migration_in_setup(MigrationState *s) 914 { 915 return s->state == MIGRATION_STATUS_SETUP; 916 } 917 918 bool migration_has_finished(MigrationState *s) 919 { 920 return s->state == MIGRATION_STATUS_COMPLETED; 921 } 922 923 bool migration_has_failed(MigrationState *s) 924 { 925 return (s->state == MIGRATION_STATUS_CANCELLED || 926 s->state == MIGRATION_STATUS_FAILED); 927 } 928 929 bool migration_in_postcopy(void) 930 { 931 MigrationState *s = migrate_get_current(); 932 933 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 934 } 935 936 bool migration_in_postcopy_after_devices(MigrationState *s) 937 { 938 return migration_in_postcopy() && s->postcopy_after_devices; 939 } 940 941 bool migration_is_idle(void) 942 { 943 MigrationState *s = migrate_get_current(); 944 945 switch (s->state) { 946 case MIGRATION_STATUS_NONE: 947 case MIGRATION_STATUS_CANCELLED: 948 case MIGRATION_STATUS_COMPLETED: 949 case MIGRATION_STATUS_FAILED: 950 return true; 951 case MIGRATION_STATUS_SETUP: 952 case MIGRATION_STATUS_CANCELLING: 953 case MIGRATION_STATUS_ACTIVE: 954 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 955 case MIGRATION_STATUS_COLO: 956 return false; 957 case MIGRATION_STATUS__MAX: 958 g_assert_not_reached(); 959 } 960 961 return false; 962 } 963 964 MigrationState *migrate_init(void) 965 { 966 MigrationState *s = migrate_get_current(); 967 968 /* 969 * Reinitialise all migration state, except 970 * parameters/capabilities that the user set, and 971 * locks. 972 */ 973 s->bytes_xfer = 0; 974 s->xfer_limit = 0; 975 s->cleanup_bh = 0; 976 s->to_dst_file = NULL; 977 s->state = MIGRATION_STATUS_NONE; 978 s->rp_state.from_dst_file = NULL; 979 s->rp_state.error = false; 980 s->mbps = 0.0; 981 s->downtime = 0; 982 s->expected_downtime = 0; 983 s->setup_time = 0; 984 s->start_postcopy = false; 985 s->postcopy_after_devices = false; 986 s->migration_thread_running = false; 987 error_free(s->error); 988 s->error = NULL; 989 990 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); 991 992 s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 993 return s; 994 } 995 996 static GSList *migration_blockers; 997 998 int migrate_add_blocker(Error *reason, Error **errp) 999 { 1000 if (only_migratable) { 1001 error_propagate(errp, error_copy(reason)); 1002 error_prepend(errp, "disallowing migration blocker " 1003 "(--only_migratable) for: "); 1004 return -EACCES; 1005 } 1006 1007 if (migration_is_idle()) { 1008 migration_blockers = g_slist_prepend(migration_blockers, reason); 1009 return 0; 1010 } 1011 1012 error_propagate(errp, error_copy(reason)); 1013 error_prepend(errp, "disallowing migration blocker (migration in " 1014 "progress) for: "); 1015 return -EBUSY; 1016 } 1017 1018 void migrate_del_blocker(Error *reason) 1019 { 1020 migration_blockers = g_slist_remove(migration_blockers, reason); 1021 } 1022 1023 void qmp_migrate_incoming(const char *uri, Error **errp) 1024 { 1025 Error *local_err = NULL; 1026 static bool once = true; 1027 1028 if (!deferred_incoming) { 1029 error_setg(errp, "For use with '-incoming defer'"); 1030 return; 1031 } 1032 if (!once) { 1033 error_setg(errp, "The incoming migration has already been started"); 1034 } 1035 1036 qemu_start_incoming_migration(uri, &local_err); 1037 1038 if (local_err) { 1039 error_propagate(errp, local_err); 1040 return; 1041 } 1042 1043 once = false; 1044 } 1045 1046 bool migration_is_blocked(Error **errp) 1047 { 1048 if (qemu_savevm_state_blocked(errp)) { 1049 return true; 1050 } 1051 1052 if (migration_blockers) { 1053 error_propagate(errp, error_copy(migration_blockers->data)); 1054 return true; 1055 } 1056 1057 return false; 1058 } 1059 1060 void qmp_migrate(const char *uri, bool has_blk, bool blk, 1061 bool has_inc, bool inc, bool has_detach, bool detach, 1062 Error **errp) 1063 { 1064 Error *local_err = NULL; 1065 MigrationState *s = migrate_get_current(); 1066 const char *p; 1067 1068 if (migration_is_setup_or_active(s->state) || 1069 s->state == MIGRATION_STATUS_CANCELLING || 1070 s->state == MIGRATION_STATUS_COLO) { 1071 error_setg(errp, QERR_MIGRATION_ACTIVE); 1072 return; 1073 } 1074 if (runstate_check(RUN_STATE_INMIGRATE)) { 1075 error_setg(errp, "Guest is waiting for an incoming migration"); 1076 return; 1077 } 1078 1079 if (migration_is_blocked(errp)) { 1080 return; 1081 } 1082 1083 if ((has_blk && blk) || (has_inc && inc)) { 1084 if (migrate_use_block() || migrate_use_block_incremental()) { 1085 error_setg(errp, "Command options are incompatible with " 1086 "current migration capabilities"); 1087 return; 1088 } 1089 migrate_set_block_enabled(true, &local_err); 1090 if (local_err) { 1091 error_propagate(errp, local_err); 1092 return; 1093 } 1094 s->must_remove_block_options = true; 1095 } 1096 1097 if (has_inc && inc) { 1098 migrate_set_block_incremental(s, true); 1099 } 1100 1101 s = migrate_init(); 1102 1103 if (strstart(uri, "tcp:", &p)) { 1104 tcp_start_outgoing_migration(s, p, &local_err); 1105 #ifdef CONFIG_RDMA 1106 } else if (strstart(uri, "rdma:", &p)) { 1107 rdma_start_outgoing_migration(s, p, &local_err); 1108 #endif 1109 } else if (strstart(uri, "exec:", &p)) { 1110 exec_start_outgoing_migration(s, p, &local_err); 1111 } else if (strstart(uri, "unix:", &p)) { 1112 unix_start_outgoing_migration(s, p, &local_err); 1113 } else if (strstart(uri, "fd:", &p)) { 1114 fd_start_outgoing_migration(s, p, &local_err); 1115 } else { 1116 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", 1117 "a valid migration protocol"); 1118 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1119 MIGRATION_STATUS_FAILED); 1120 return; 1121 } 1122 1123 if (local_err) { 1124 migrate_fd_error(s, local_err); 1125 error_propagate(errp, local_err); 1126 return; 1127 } 1128 } 1129 1130 void qmp_migrate_cancel(Error **errp) 1131 { 1132 migrate_fd_cancel(migrate_get_current()); 1133 } 1134 1135 void qmp_migrate_set_cache_size(int64_t value, Error **errp) 1136 { 1137 MigrationState *s = migrate_get_current(); 1138 int64_t new_size; 1139 1140 /* Check for truncation */ 1141 if (value != (size_t)value) { 1142 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1143 "exceeding address space"); 1144 return; 1145 } 1146 1147 /* Cache should not be larger than guest ram size */ 1148 if (value > ram_bytes_total()) { 1149 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1150 "exceeds guest ram size "); 1151 return; 1152 } 1153 1154 new_size = xbzrle_cache_resize(value); 1155 if (new_size < 0) { 1156 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", 1157 "is smaller than page size"); 1158 return; 1159 } 1160 1161 s->xbzrle_cache_size = new_size; 1162 } 1163 1164 int64_t qmp_query_migrate_cache_size(Error **errp) 1165 { 1166 return migrate_xbzrle_cache_size(); 1167 } 1168 1169 void qmp_migrate_set_speed(int64_t value, Error **errp) 1170 { 1171 MigrationParameters p = { 1172 .has_max_bandwidth = true, 1173 .max_bandwidth = value, 1174 }; 1175 1176 qmp_migrate_set_parameters(&p, errp); 1177 } 1178 1179 void qmp_migrate_set_downtime(double value, Error **errp) 1180 { 1181 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) { 1182 error_setg(errp, "Parameter 'downtime_limit' expects an integer in " 1183 "the range of 0 to %d seconds", 1184 MAX_MIGRATE_DOWNTIME_SECONDS); 1185 return; 1186 } 1187 1188 value *= 1000; /* Convert to milliseconds */ 1189 value = MAX(0, MIN(INT64_MAX, value)); 1190 1191 MigrationParameters p = { 1192 .has_downtime_limit = true, 1193 .downtime_limit = value, 1194 }; 1195 1196 qmp_migrate_set_parameters(&p, errp); 1197 } 1198 1199 bool migrate_release_ram(void) 1200 { 1201 MigrationState *s; 1202 1203 s = migrate_get_current(); 1204 1205 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM]; 1206 } 1207 1208 bool migrate_postcopy_ram(void) 1209 { 1210 MigrationState *s; 1211 1212 s = migrate_get_current(); 1213 1214 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 1215 } 1216 1217 bool migrate_auto_converge(void) 1218 { 1219 MigrationState *s; 1220 1221 s = migrate_get_current(); 1222 1223 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; 1224 } 1225 1226 bool migrate_zero_blocks(void) 1227 { 1228 MigrationState *s; 1229 1230 s = migrate_get_current(); 1231 1232 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; 1233 } 1234 1235 bool migrate_use_compression(void) 1236 { 1237 MigrationState *s; 1238 1239 s = migrate_get_current(); 1240 1241 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS]; 1242 } 1243 1244 int migrate_compress_level(void) 1245 { 1246 MigrationState *s; 1247 1248 s = migrate_get_current(); 1249 1250 return s->parameters.compress_level; 1251 } 1252 1253 int migrate_compress_threads(void) 1254 { 1255 MigrationState *s; 1256 1257 s = migrate_get_current(); 1258 1259 return s->parameters.compress_threads; 1260 } 1261 1262 int migrate_decompress_threads(void) 1263 { 1264 MigrationState *s; 1265 1266 s = migrate_get_current(); 1267 1268 return s->parameters.decompress_threads; 1269 } 1270 1271 bool migrate_use_events(void) 1272 { 1273 MigrationState *s; 1274 1275 s = migrate_get_current(); 1276 1277 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS]; 1278 } 1279 1280 int migrate_use_xbzrle(void) 1281 { 1282 MigrationState *s; 1283 1284 s = migrate_get_current(); 1285 1286 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; 1287 } 1288 1289 int64_t migrate_xbzrle_cache_size(void) 1290 { 1291 MigrationState *s; 1292 1293 s = migrate_get_current(); 1294 1295 return s->xbzrle_cache_size; 1296 } 1297 1298 bool migrate_use_block(void) 1299 { 1300 MigrationState *s; 1301 1302 s = migrate_get_current(); 1303 1304 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK]; 1305 } 1306 1307 bool migrate_use_block_incremental(void) 1308 { 1309 MigrationState *s; 1310 1311 s = migrate_get_current(); 1312 1313 return s->parameters.block_incremental; 1314 } 1315 1316 /* migration thread support */ 1317 /* 1318 * Something bad happened to the RP stream, mark an error 1319 * The caller shall print or trace something to indicate why 1320 */ 1321 static void mark_source_rp_bad(MigrationState *s) 1322 { 1323 s->rp_state.error = true; 1324 } 1325 1326 static struct rp_cmd_args { 1327 ssize_t len; /* -1 = variable */ 1328 const char *name; 1329 } rp_cmd_args[] = { 1330 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, 1331 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, 1332 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, 1333 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, 1334 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, 1335 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, 1336 }; 1337 1338 /* 1339 * Process a request for pages received on the return path, 1340 * We're allowed to send more than requested (e.g. to round to our page size) 1341 * and we don't need to send pages that have already been sent. 1342 */ 1343 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, 1344 ram_addr_t start, size_t len) 1345 { 1346 long our_host_ps = getpagesize(); 1347 1348 trace_migrate_handle_rp_req_pages(rbname, start, len); 1349 1350 /* 1351 * Since we currently insist on matching page sizes, just sanity check 1352 * we're being asked for whole host pages. 1353 */ 1354 if (start & (our_host_ps-1) || 1355 (len & (our_host_ps-1))) { 1356 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT 1357 " len: %zd", __func__, start, len); 1358 mark_source_rp_bad(ms); 1359 return; 1360 } 1361 1362 if (ram_save_queue_pages(rbname, start, len)) { 1363 mark_source_rp_bad(ms); 1364 } 1365 } 1366 1367 /* 1368 * Handles messages sent on the return path towards the source VM 1369 * 1370 */ 1371 static void *source_return_path_thread(void *opaque) 1372 { 1373 MigrationState *ms = opaque; 1374 QEMUFile *rp = ms->rp_state.from_dst_file; 1375 uint16_t header_len, header_type; 1376 uint8_t buf[512]; 1377 uint32_t tmp32, sibling_error; 1378 ram_addr_t start = 0; /* =0 to silence warning */ 1379 size_t len = 0, expected_len; 1380 int res; 1381 1382 trace_source_return_path_thread_entry(); 1383 while (!ms->rp_state.error && !qemu_file_get_error(rp) && 1384 migration_is_setup_or_active(ms->state)) { 1385 trace_source_return_path_thread_loop_top(); 1386 header_type = qemu_get_be16(rp); 1387 header_len = qemu_get_be16(rp); 1388 1389 if (header_type >= MIG_RP_MSG_MAX || 1390 header_type == MIG_RP_MSG_INVALID) { 1391 error_report("RP: Received invalid message 0x%04x length 0x%04x", 1392 header_type, header_len); 1393 mark_source_rp_bad(ms); 1394 goto out; 1395 } 1396 1397 if ((rp_cmd_args[header_type].len != -1 && 1398 header_len != rp_cmd_args[header_type].len) || 1399 header_len > sizeof(buf)) { 1400 error_report("RP: Received '%s' message (0x%04x) with" 1401 "incorrect length %d expecting %zu", 1402 rp_cmd_args[header_type].name, header_type, header_len, 1403 (size_t)rp_cmd_args[header_type].len); 1404 mark_source_rp_bad(ms); 1405 goto out; 1406 } 1407 1408 /* We know we've got a valid header by this point */ 1409 res = qemu_get_buffer(rp, buf, header_len); 1410 if (res != header_len) { 1411 error_report("RP: Failed reading data for message 0x%04x" 1412 " read %d expected %d", 1413 header_type, res, header_len); 1414 mark_source_rp_bad(ms); 1415 goto out; 1416 } 1417 1418 /* OK, we have the message and the data */ 1419 switch (header_type) { 1420 case MIG_RP_MSG_SHUT: 1421 sibling_error = ldl_be_p(buf); 1422 trace_source_return_path_thread_shut(sibling_error); 1423 if (sibling_error) { 1424 error_report("RP: Sibling indicated error %d", sibling_error); 1425 mark_source_rp_bad(ms); 1426 } 1427 /* 1428 * We'll let the main thread deal with closing the RP 1429 * we could do a shutdown(2) on it, but we're the only user 1430 * anyway, so there's nothing gained. 1431 */ 1432 goto out; 1433 1434 case MIG_RP_MSG_PONG: 1435 tmp32 = ldl_be_p(buf); 1436 trace_source_return_path_thread_pong(tmp32); 1437 break; 1438 1439 case MIG_RP_MSG_REQ_PAGES: 1440 start = ldq_be_p(buf); 1441 len = ldl_be_p(buf + 8); 1442 migrate_handle_rp_req_pages(ms, NULL, start, len); 1443 break; 1444 1445 case MIG_RP_MSG_REQ_PAGES_ID: 1446 expected_len = 12 + 1; /* header + termination */ 1447 1448 if (header_len >= expected_len) { 1449 start = ldq_be_p(buf); 1450 len = ldl_be_p(buf + 8); 1451 /* Now we expect an idstr */ 1452 tmp32 = buf[12]; /* Length of the following idstr */ 1453 buf[13 + tmp32] = '\0'; 1454 expected_len += tmp32; 1455 } 1456 if (header_len != expected_len) { 1457 error_report("RP: Req_Page_id with length %d expecting %zd", 1458 header_len, expected_len); 1459 mark_source_rp_bad(ms); 1460 goto out; 1461 } 1462 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); 1463 break; 1464 1465 default: 1466 break; 1467 } 1468 } 1469 if (qemu_file_get_error(rp)) { 1470 trace_source_return_path_thread_bad_end(); 1471 mark_source_rp_bad(ms); 1472 } 1473 1474 trace_source_return_path_thread_end(); 1475 out: 1476 ms->rp_state.from_dst_file = NULL; 1477 qemu_fclose(rp); 1478 return NULL; 1479 } 1480 1481 static int open_return_path_on_source(MigrationState *ms) 1482 { 1483 1484 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); 1485 if (!ms->rp_state.from_dst_file) { 1486 return -1; 1487 } 1488 1489 trace_open_return_path_on_source(); 1490 qemu_thread_create(&ms->rp_state.rp_thread, "return path", 1491 source_return_path_thread, ms, QEMU_THREAD_JOINABLE); 1492 1493 trace_open_return_path_on_source_continue(); 1494 1495 return 0; 1496 } 1497 1498 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */ 1499 static int await_return_path_close_on_source(MigrationState *ms) 1500 { 1501 /* 1502 * If this is a normal exit then the destination will send a SHUT and the 1503 * rp_thread will exit, however if there's an error we need to cause 1504 * it to exit. 1505 */ 1506 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) { 1507 /* 1508 * shutdown(2), if we have it, will cause it to unblock if it's stuck 1509 * waiting for the destination. 1510 */ 1511 qemu_file_shutdown(ms->rp_state.from_dst_file); 1512 mark_source_rp_bad(ms); 1513 } 1514 trace_await_return_path_close_on_source_joining(); 1515 qemu_thread_join(&ms->rp_state.rp_thread); 1516 trace_await_return_path_close_on_source_close(); 1517 return ms->rp_state.error; 1518 } 1519 1520 /* 1521 * Switch from normal iteration to postcopy 1522 * Returns non-0 on error 1523 */ 1524 static int postcopy_start(MigrationState *ms, bool *old_vm_running) 1525 { 1526 int ret; 1527 QIOChannelBuffer *bioc; 1528 QEMUFile *fb; 1529 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1530 bool restart_block = false; 1531 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE, 1532 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1533 1534 trace_postcopy_start(); 1535 qemu_mutex_lock_iothread(); 1536 trace_postcopy_start_set_run(); 1537 1538 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1539 *old_vm_running = runstate_is_running(); 1540 global_state_store(); 1541 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1542 if (ret < 0) { 1543 goto fail; 1544 } 1545 1546 ret = bdrv_inactivate_all(); 1547 if (ret < 0) { 1548 goto fail; 1549 } 1550 restart_block = true; 1551 1552 /* 1553 * Cause any non-postcopiable, but iterative devices to 1554 * send out their final data. 1555 */ 1556 qemu_savevm_state_complete_precopy(ms->to_dst_file, true); 1557 1558 /* 1559 * in Finish migrate and with the io-lock held everything should 1560 * be quiet, but we've potentially still got dirty pages and we 1561 * need to tell the destination to throw any pages it's already received 1562 * that are dirty 1563 */ 1564 if (ram_postcopy_send_discard_bitmap(ms)) { 1565 error_report("postcopy send discard bitmap failed"); 1566 goto fail; 1567 } 1568 1569 /* 1570 * send rest of state - note things that are doing postcopy 1571 * will notice we're in POSTCOPY_ACTIVE and not actually 1572 * wrap their state up here 1573 */ 1574 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); 1575 /* Ping just for debugging, helps line traces up */ 1576 qemu_savevm_send_ping(ms->to_dst_file, 2); 1577 1578 /* 1579 * While loading the device state we may trigger page transfer 1580 * requests and the fd must be free to process those, and thus 1581 * the destination must read the whole device state off the fd before 1582 * it starts processing it. Unfortunately the ad-hoc migration format 1583 * doesn't allow the destination to know the size to read without fully 1584 * parsing it through each devices load-state code (especially the open 1585 * coded devices that use get/put). 1586 * So we wrap the device state up in a package with a length at the start; 1587 * to do this we use a qemu_buf to hold the whole of the device state. 1588 */ 1589 bioc = qio_channel_buffer_new(4096); 1590 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer"); 1591 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 1592 object_unref(OBJECT(bioc)); 1593 1594 /* 1595 * Make sure the receiver can get incoming pages before we send the rest 1596 * of the state 1597 */ 1598 qemu_savevm_send_postcopy_listen(fb); 1599 1600 qemu_savevm_state_complete_precopy(fb, false); 1601 qemu_savevm_send_ping(fb, 3); 1602 1603 qemu_savevm_send_postcopy_run(fb); 1604 1605 /* <><> end of stuff going into the package */ 1606 1607 /* Last point of recovery; as soon as we send the package the destination 1608 * can open devices and potentially start running. 1609 * Lets just check again we've not got any errors. 1610 */ 1611 ret = qemu_file_get_error(ms->to_dst_file); 1612 if (ret) { 1613 error_report("postcopy_start: Migration stream errored (pre package)"); 1614 goto fail_closefb; 1615 } 1616 1617 restart_block = false; 1618 1619 /* Now send that blob */ 1620 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) { 1621 goto fail_closefb; 1622 } 1623 qemu_fclose(fb); 1624 1625 /* Send a notify to give a chance for anything that needs to happen 1626 * at the transition to postcopy and after the device state; in particular 1627 * spice needs to trigger a transition now 1628 */ 1629 ms->postcopy_after_devices = true; 1630 notifier_list_notify(&migration_state_notifiers, ms); 1631 1632 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop; 1633 1634 qemu_mutex_unlock_iothread(); 1635 1636 /* 1637 * Although this ping is just for debug, it could potentially be 1638 * used for getting a better measurement of downtime at the source. 1639 */ 1640 qemu_savevm_send_ping(ms->to_dst_file, 4); 1641 1642 if (migrate_release_ram()) { 1643 ram_postcopy_migrated_memory_release(ms); 1644 } 1645 1646 ret = qemu_file_get_error(ms->to_dst_file); 1647 if (ret) { 1648 error_report("postcopy_start: Migration stream errored"); 1649 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1650 MIGRATION_STATUS_FAILED); 1651 } 1652 1653 return ret; 1654 1655 fail_closefb: 1656 qemu_fclose(fb); 1657 fail: 1658 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1659 MIGRATION_STATUS_FAILED); 1660 if (restart_block) { 1661 /* A failure happened early enough that we know the destination hasn't 1662 * accessed block devices, so we're safe to recover. 1663 */ 1664 Error *local_err = NULL; 1665 1666 bdrv_invalidate_cache_all(&local_err); 1667 if (local_err) { 1668 error_report_err(local_err); 1669 } 1670 } 1671 qemu_mutex_unlock_iothread(); 1672 return -1; 1673 } 1674 1675 /** 1676 * migration_completion: Used by migration_thread when there's not much left. 1677 * The caller 'breaks' the loop when this returns. 1678 * 1679 * @s: Current migration state 1680 * @current_active_state: The migration state we expect to be in 1681 * @*old_vm_running: Pointer to old_vm_running flag 1682 * @*start_time: Pointer to time to update 1683 */ 1684 static void migration_completion(MigrationState *s, int current_active_state, 1685 bool *old_vm_running, 1686 int64_t *start_time) 1687 { 1688 int ret; 1689 1690 if (s->state == MIGRATION_STATUS_ACTIVE) { 1691 qemu_mutex_lock_iothread(); 1692 *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1693 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 1694 *old_vm_running = runstate_is_running(); 1695 ret = global_state_store(); 1696 1697 if (!ret) { 1698 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 1699 if (ret >= 0) { 1700 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX); 1701 qemu_savevm_state_complete_precopy(s->to_dst_file, false); 1702 } 1703 /* 1704 * Don't mark the image with BDRV_O_INACTIVE flag if 1705 * we will go into COLO stage later. 1706 */ 1707 if (ret >= 0 && !migrate_colo_enabled()) { 1708 ret = bdrv_inactivate_all(); 1709 if (ret >= 0) { 1710 s->block_inactive = true; 1711 } 1712 } 1713 } 1714 qemu_mutex_unlock_iothread(); 1715 1716 if (ret < 0) { 1717 goto fail; 1718 } 1719 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1720 trace_migration_completion_postcopy_end(); 1721 1722 qemu_savevm_state_complete_postcopy(s->to_dst_file); 1723 trace_migration_completion_postcopy_end_after_complete(); 1724 } 1725 1726 /* 1727 * If rp was opened we must clean up the thread before 1728 * cleaning everything else up (since if there are no failures 1729 * it will wait for the destination to send it's status in 1730 * a SHUT command). 1731 */ 1732 if (s->rp_state.from_dst_file) { 1733 int rp_error; 1734 trace_migration_return_path_end_before(); 1735 rp_error = await_return_path_close_on_source(s); 1736 trace_migration_return_path_end_after(rp_error); 1737 if (rp_error) { 1738 goto fail_invalidate; 1739 } 1740 } 1741 1742 if (qemu_file_get_error(s->to_dst_file)) { 1743 trace_migration_completion_file_err(); 1744 goto fail_invalidate; 1745 } 1746 1747 if (!migrate_colo_enabled()) { 1748 migrate_set_state(&s->state, current_active_state, 1749 MIGRATION_STATUS_COMPLETED); 1750 } 1751 1752 return; 1753 1754 fail_invalidate: 1755 /* If not doing postcopy, vm_start() will be called: let's regain 1756 * control on images. 1757 */ 1758 if (s->state == MIGRATION_STATUS_ACTIVE) { 1759 Error *local_err = NULL; 1760 1761 qemu_mutex_lock_iothread(); 1762 bdrv_invalidate_cache_all(&local_err); 1763 if (local_err) { 1764 error_report_err(local_err); 1765 } else { 1766 s->block_inactive = false; 1767 } 1768 qemu_mutex_unlock_iothread(); 1769 } 1770 1771 fail: 1772 migrate_set_state(&s->state, current_active_state, 1773 MIGRATION_STATUS_FAILED); 1774 } 1775 1776 bool migrate_colo_enabled(void) 1777 { 1778 MigrationState *s = migrate_get_current(); 1779 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO]; 1780 } 1781 1782 /* 1783 * Master migration thread on the source VM. 1784 * It drives the migration and pumps the data down the outgoing channel. 1785 */ 1786 static void *migration_thread(void *opaque) 1787 { 1788 MigrationState *s = opaque; 1789 /* Used by the bandwidth calcs, updated later */ 1790 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1791 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); 1792 int64_t initial_bytes = 0; 1793 /* 1794 * The final stage happens when the remaining data is smaller than 1795 * this threshold; it's calculated from the requested downtime and 1796 * measured bandwidth 1797 */ 1798 int64_t threshold_size = 0; 1799 int64_t start_time = initial_time; 1800 int64_t end_time; 1801 bool old_vm_running = false; 1802 bool entered_postcopy = false; 1803 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */ 1804 enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE; 1805 bool enable_colo = migrate_colo_enabled(); 1806 1807 rcu_register_thread(); 1808 1809 qemu_savevm_state_header(s->to_dst_file); 1810 1811 /* 1812 * If we opened the return path, we need to make sure dst has it 1813 * opened as well. 1814 */ 1815 if (s->rp_state.from_dst_file) { 1816 /* Now tell the dest that it should open its end so it can reply */ 1817 qemu_savevm_send_open_return_path(s->to_dst_file); 1818 1819 /* And do a ping that will make stuff easier to debug */ 1820 qemu_savevm_send_ping(s->to_dst_file, 1); 1821 } 1822 1823 if (migrate_postcopy_ram()) { 1824 /* 1825 * Tell the destination that we *might* want to do postcopy later; 1826 * if the other end can't do postcopy it should fail now, nice and 1827 * early. 1828 */ 1829 qemu_savevm_send_postcopy_advise(s->to_dst_file); 1830 } 1831 1832 qemu_savevm_state_begin(s->to_dst_file); 1833 1834 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; 1835 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1836 MIGRATION_STATUS_ACTIVE); 1837 1838 trace_migration_thread_setup_complete(); 1839 1840 while (s->state == MIGRATION_STATUS_ACTIVE || 1841 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1842 int64_t current_time; 1843 uint64_t pending_size; 1844 1845 if (!qemu_file_rate_limit(s->to_dst_file)) { 1846 uint64_t pend_post, pend_nonpost; 1847 1848 qemu_savevm_state_pending(s->to_dst_file, threshold_size, 1849 &pend_nonpost, &pend_post); 1850 pending_size = pend_nonpost + pend_post; 1851 trace_migrate_pending(pending_size, threshold_size, 1852 pend_post, pend_nonpost); 1853 if (pending_size && pending_size >= threshold_size) { 1854 /* Still a significant amount to transfer */ 1855 1856 if (migrate_postcopy_ram() && 1857 s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE && 1858 pend_nonpost <= threshold_size && 1859 atomic_read(&s->start_postcopy)) { 1860 1861 if (!postcopy_start(s, &old_vm_running)) { 1862 current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE; 1863 entered_postcopy = true; 1864 } 1865 1866 continue; 1867 } 1868 /* Just another iteration step */ 1869 qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy); 1870 } else { 1871 trace_migration_thread_low_pending(pending_size); 1872 migration_completion(s, current_active_state, 1873 &old_vm_running, &start_time); 1874 break; 1875 } 1876 } 1877 1878 if (qemu_file_get_error(s->to_dst_file)) { 1879 migrate_set_state(&s->state, current_active_state, 1880 MIGRATION_STATUS_FAILED); 1881 trace_migration_thread_file_err(); 1882 break; 1883 } 1884 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1885 if (current_time >= initial_time + BUFFER_DELAY) { 1886 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file) - 1887 initial_bytes; 1888 uint64_t time_spent = current_time - initial_time; 1889 double bandwidth = (double)transferred_bytes / time_spent; 1890 threshold_size = bandwidth * s->parameters.downtime_limit; 1891 1892 s->mbps = (((double) transferred_bytes * 8.0) / 1893 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; 1894 1895 trace_migrate_transferred(transferred_bytes, time_spent, 1896 bandwidth, threshold_size); 1897 /* if we haven't sent anything, we don't want to recalculate 1898 10000 is a small enough number for our purposes */ 1899 if (ram_counters.dirty_pages_rate && transferred_bytes > 10000) { 1900 s->expected_downtime = ram_counters.dirty_pages_rate * 1901 qemu_target_page_size() / bandwidth; 1902 } 1903 1904 qemu_file_reset_rate_limit(s->to_dst_file); 1905 initial_time = current_time; 1906 initial_bytes = qemu_ftell(s->to_dst_file); 1907 } 1908 if (qemu_file_rate_limit(s->to_dst_file)) { 1909 /* usleep expects microseconds */ 1910 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); 1911 } 1912 } 1913 1914 trace_migration_thread_after_loop(); 1915 /* If we enabled cpu throttling for auto-converge, turn it off. */ 1916 cpu_throttle_stop(); 1917 end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1918 1919 qemu_mutex_lock_iothread(); 1920 /* 1921 * The resource has been allocated by migration will be reused in COLO 1922 * process, so don't release them. 1923 */ 1924 if (!enable_colo) { 1925 qemu_savevm_state_cleanup(); 1926 } 1927 if (s->state == MIGRATION_STATUS_COMPLETED) { 1928 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file); 1929 s->total_time = end_time - s->total_time; 1930 if (!entered_postcopy) { 1931 s->downtime = end_time - start_time; 1932 } 1933 if (s->total_time) { 1934 s->mbps = (((double) transferred_bytes * 8.0) / 1935 ((double) s->total_time)) / 1000; 1936 } 1937 runstate_set(RUN_STATE_POSTMIGRATE); 1938 } else { 1939 if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) { 1940 migrate_start_colo_process(s); 1941 qemu_savevm_state_cleanup(); 1942 /* 1943 * Fixme: we will run VM in COLO no matter its old running state. 1944 * After exited COLO, we will keep running. 1945 */ 1946 old_vm_running = true; 1947 } 1948 if (old_vm_running && !entered_postcopy) { 1949 vm_start(); 1950 } else { 1951 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) { 1952 runstate_set(RUN_STATE_POSTMIGRATE); 1953 } 1954 } 1955 } 1956 qemu_bh_schedule(s->cleanup_bh); 1957 qemu_mutex_unlock_iothread(); 1958 1959 rcu_unregister_thread(); 1960 return NULL; 1961 } 1962 1963 void migrate_fd_connect(MigrationState *s) 1964 { 1965 s->expected_downtime = s->parameters.downtime_limit; 1966 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); 1967 1968 qemu_file_set_blocking(s->to_dst_file, true); 1969 qemu_file_set_rate_limit(s->to_dst_file, 1970 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 1971 1972 /* Notify before starting migration thread */ 1973 notifier_list_notify(&migration_state_notifiers, s); 1974 1975 /* 1976 * Open the return path; currently for postcopy but other things might 1977 * also want it. 1978 */ 1979 if (migrate_postcopy_ram()) { 1980 if (open_return_path_on_source(s)) { 1981 error_report("Unable to open return-path for postcopy"); 1982 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1983 MIGRATION_STATUS_FAILED); 1984 migrate_fd_cleanup(s); 1985 return; 1986 } 1987 } 1988 1989 migrate_compress_threads_create(); 1990 qemu_thread_create(&s->thread, "live_migration", migration_thread, s, 1991 QEMU_THREAD_JOINABLE); 1992 s->migration_thread_running = true; 1993 } 1994 1995