1 /* 2 * QEMU live migration 3 * 4 * Copyright IBM, Corp. 2008 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 * Contributions after 2012-01-13 are licensed under the terms of the 13 * GNU GPL, version 2 or (at your option) any later version. 14 */ 15 16 #include "qemu/osdep.h" 17 #include "qemu/cutils.h" 18 #include "qemu/error-report.h" 19 #include "migration/blocker.h" 20 #include "exec.h" 21 #include "fd.h" 22 #include "socket.h" 23 #include "rdma.h" 24 #include "ram.h" 25 #include "migration/global_state.h" 26 #include "migration/misc.h" 27 #include "migration.h" 28 #include "savevm.h" 29 #include "qemu-file-channel.h" 30 #include "qemu-file.h" 31 #include "migration/vmstate.h" 32 #include "block/block.h" 33 #include "qapi/error.h" 34 #include "qapi/qapi-commands-migration.h" 35 #include "qapi/qapi-events-migration.h" 36 #include "qapi/qmp/qerror.h" 37 #include "qapi/qmp/qnull.h" 38 #include "qemu/rcu.h" 39 #include "block.h" 40 #include "postcopy-ram.h" 41 #include "qemu/thread.h" 42 #include "trace.h" 43 #include "exec/target_page.h" 44 #include "io/channel-buffer.h" 45 #include "migration/colo.h" 46 #include "hw/boards.h" 47 #include "monitor/monitor.h" 48 49 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ 50 51 /* Amount of time to allocate to each "chunk" of bandwidth-throttled 52 * data. */ 53 #define BUFFER_DELAY 100 54 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) 55 56 /* Time in milliseconds we are allowed to stop the source, 57 * for sending the last part */ 58 #define DEFAULT_MIGRATE_SET_DOWNTIME 300 59 60 /* Maximum migrate downtime set to 2000 seconds */ 61 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000 62 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000) 63 64 /* Default compression thread count */ 65 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8 66 /* Default decompression thread count, usually decompression is at 67 * least 4 times as fast as compression.*/ 68 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2 69 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */ 70 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1 71 /* Define default autoconverge cpu throttle migration parameters */ 72 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20 73 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10 74 #define DEFAULT_MIGRATE_MAX_CPU_THROTTLE 99 75 76 /* Migration XBZRLE default cache size */ 77 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024) 78 79 /* The delay time (in ms) between two COLO checkpoints */ 80 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100) 81 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2 82 #define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16 83 84 /* Background transfer rate for postcopy, 0 means unlimited, note 85 * that page requests can still exceed this limit. 86 */ 87 #define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0 88 89 static NotifierList migration_state_notifiers = 90 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); 91 92 static bool deferred_incoming; 93 94 /* Messages sent on the return path from destination to source */ 95 enum mig_rp_message_type { 96 MIG_RP_MSG_INVALID = 0, /* Must be 0 */ 97 MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */ 98 MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */ 99 100 MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */ 101 MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */ 102 MIG_RP_MSG_RECV_BITMAP, /* send recved_bitmap back to source */ 103 MIG_RP_MSG_RESUME_ACK, /* tell source that we are ready to resume */ 104 105 MIG_RP_MSG_MAX 106 }; 107 108 /* When we add fault tolerance, we could have several 109 migrations at once. For now we don't need to add 110 dynamic creation of migration */ 111 112 static MigrationState *current_migration; 113 static MigrationIncomingState *current_incoming; 114 115 static bool migration_object_check(MigrationState *ms, Error **errp); 116 static int migration_maybe_pause(MigrationState *s, 117 int *current_active_state, 118 int new_state); 119 120 void migration_object_init(void) 121 { 122 MachineState *ms = MACHINE(qdev_get_machine()); 123 Error *err = NULL; 124 125 /* This can only be called once. */ 126 assert(!current_migration); 127 current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION)); 128 129 /* 130 * Init the migrate incoming object as well no matter whether 131 * we'll use it or not. 132 */ 133 assert(!current_incoming); 134 current_incoming = g_new0(MigrationIncomingState, 1); 135 current_incoming->state = MIGRATION_STATUS_NONE; 136 current_incoming->postcopy_remote_fds = 137 g_array_new(FALSE, TRUE, sizeof(struct PostCopyFD)); 138 qemu_mutex_init(¤t_incoming->rp_mutex); 139 qemu_event_init(¤t_incoming->main_thread_load_event, false); 140 qemu_sem_init(¤t_incoming->postcopy_pause_sem_dst, 0); 141 qemu_sem_init(¤t_incoming->postcopy_pause_sem_fault, 0); 142 143 init_dirty_bitmap_incoming_migration(); 144 145 if (!migration_object_check(current_migration, &err)) { 146 error_report_err(err); 147 exit(1); 148 } 149 150 /* 151 * We cannot really do this in migration_instance_init() since at 152 * that time global properties are not yet applied, then this 153 * value will be definitely replaced by something else. 154 */ 155 if (ms->enforce_config_section) { 156 current_migration->send_configuration = true; 157 } 158 } 159 160 void migration_object_finalize(void) 161 { 162 object_unref(OBJECT(current_migration)); 163 } 164 165 /* For outgoing */ 166 MigrationState *migrate_get_current(void) 167 { 168 /* This can only be called after the object created. */ 169 assert(current_migration); 170 return current_migration; 171 } 172 173 MigrationIncomingState *migration_incoming_get_current(void) 174 { 175 assert(current_incoming); 176 return current_incoming; 177 } 178 179 void migration_incoming_state_destroy(void) 180 { 181 struct MigrationIncomingState *mis = migration_incoming_get_current(); 182 183 if (mis->to_src_file) { 184 /* Tell source that we are done */ 185 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0); 186 qemu_fclose(mis->to_src_file); 187 mis->to_src_file = NULL; 188 } 189 190 if (mis->from_src_file) { 191 qemu_fclose(mis->from_src_file); 192 mis->from_src_file = NULL; 193 } 194 if (mis->postcopy_remote_fds) { 195 g_array_free(mis->postcopy_remote_fds, TRUE); 196 mis->postcopy_remote_fds = NULL; 197 } 198 199 qemu_event_reset(&mis->main_thread_load_event); 200 } 201 202 static void migrate_generate_event(int new_state) 203 { 204 if (migrate_use_events()) { 205 qapi_event_send_migration(new_state); 206 } 207 } 208 209 static bool migrate_late_block_activate(void) 210 { 211 MigrationState *s; 212 213 s = migrate_get_current(); 214 215 return s->enabled_capabilities[ 216 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE]; 217 } 218 219 /* 220 * Called on -incoming with a defer: uri. 221 * The migration can be started later after any parameters have been 222 * changed. 223 */ 224 static void deferred_incoming_migration(Error **errp) 225 { 226 if (deferred_incoming) { 227 error_setg(errp, "Incoming migration already deferred"); 228 } 229 deferred_incoming = true; 230 } 231 232 /* 233 * Send a message on the return channel back to the source 234 * of the migration. 235 */ 236 static int migrate_send_rp_message(MigrationIncomingState *mis, 237 enum mig_rp_message_type message_type, 238 uint16_t len, void *data) 239 { 240 int ret = 0; 241 242 trace_migrate_send_rp_message((int)message_type, len); 243 qemu_mutex_lock(&mis->rp_mutex); 244 245 /* 246 * It's possible that the file handle got lost due to network 247 * failures. 248 */ 249 if (!mis->to_src_file) { 250 ret = -EIO; 251 goto error; 252 } 253 254 qemu_put_be16(mis->to_src_file, (unsigned int)message_type); 255 qemu_put_be16(mis->to_src_file, len); 256 qemu_put_buffer(mis->to_src_file, data, len); 257 qemu_fflush(mis->to_src_file); 258 259 /* It's possible that qemu file got error during sending */ 260 ret = qemu_file_get_error(mis->to_src_file); 261 262 error: 263 qemu_mutex_unlock(&mis->rp_mutex); 264 return ret; 265 } 266 267 /* Request a range of pages from the source VM at the given 268 * start address. 269 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same 270 * as the last request (a name must have been given previously) 271 * Start: Address offset within the RB 272 * Len: Length in bytes required - must be a multiple of pagesize 273 */ 274 int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, 275 ram_addr_t start, size_t len) 276 { 277 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */ 278 size_t msglen = 12; /* start + len */ 279 enum mig_rp_message_type msg_type; 280 281 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); 282 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); 283 284 if (rbname) { 285 int rbname_len = strlen(rbname); 286 assert(rbname_len < 256); 287 288 bufc[msglen++] = rbname_len; 289 memcpy(bufc + msglen, rbname, rbname_len); 290 msglen += rbname_len; 291 msg_type = MIG_RP_MSG_REQ_PAGES_ID; 292 } else { 293 msg_type = MIG_RP_MSG_REQ_PAGES; 294 } 295 296 return migrate_send_rp_message(mis, msg_type, msglen, bufc); 297 } 298 299 static bool migration_colo_enabled; 300 bool migration_incoming_colo_enabled(void) 301 { 302 return migration_colo_enabled; 303 } 304 305 void migration_incoming_disable_colo(void) 306 { 307 migration_colo_enabled = false; 308 } 309 310 void migration_incoming_enable_colo(void) 311 { 312 migration_colo_enabled = true; 313 } 314 315 void qemu_start_incoming_migration(const char *uri, Error **errp) 316 { 317 const char *p; 318 319 qapi_event_send_migration(MIGRATION_STATUS_SETUP); 320 if (!strcmp(uri, "defer")) { 321 deferred_incoming_migration(errp); 322 } else if (strstart(uri, "tcp:", &p)) { 323 tcp_start_incoming_migration(p, errp); 324 #ifdef CONFIG_RDMA 325 } else if (strstart(uri, "rdma:", &p)) { 326 rdma_start_incoming_migration(p, errp); 327 #endif 328 } else if (strstart(uri, "exec:", &p)) { 329 exec_start_incoming_migration(p, errp); 330 } else if (strstart(uri, "unix:", &p)) { 331 unix_start_incoming_migration(p, errp); 332 } else if (strstart(uri, "fd:", &p)) { 333 fd_start_incoming_migration(p, errp); 334 } else { 335 error_setg(errp, "unknown migration protocol: %s", uri); 336 } 337 } 338 339 static void process_incoming_migration_bh(void *opaque) 340 { 341 Error *local_err = NULL; 342 MigrationIncomingState *mis = opaque; 343 344 /* If capability late_block_activate is set: 345 * Only fire up the block code now if we're going to restart the 346 * VM, else 'cont' will do it. 347 * This causes file locking to happen; so we don't want it to happen 348 * unless we really are starting the VM. 349 */ 350 if (!migrate_late_block_activate() || 351 (autostart && (!global_state_received() || 352 global_state_get_runstate() == RUN_STATE_RUNNING))) { 353 /* Make sure all file formats flush their mutable metadata. 354 * If we get an error here, just don't restart the VM yet. */ 355 bdrv_invalidate_cache_all(&local_err); 356 if (local_err) { 357 error_report_err(local_err); 358 local_err = NULL; 359 autostart = false; 360 } 361 } 362 363 /* 364 * This must happen after all error conditions are dealt with and 365 * we're sure the VM is going to be running on this host. 366 */ 367 qemu_announce_self(); 368 369 if (multifd_load_cleanup(&local_err) != 0) { 370 error_report_err(local_err); 371 autostart = false; 372 } 373 /* If global state section was not received or we are in running 374 state, we need to obey autostart. Any other state is set with 375 runstate_set. */ 376 377 dirty_bitmap_mig_before_vm_start(); 378 379 if (!global_state_received() || 380 global_state_get_runstate() == RUN_STATE_RUNNING) { 381 if (autostart) { 382 vm_start(); 383 } else { 384 runstate_set(RUN_STATE_PAUSED); 385 } 386 } else { 387 runstate_set(global_state_get_runstate()); 388 } 389 /* 390 * This must happen after any state changes since as soon as an external 391 * observer sees this event they might start to prod at the VM assuming 392 * it's ready to use. 393 */ 394 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 395 MIGRATION_STATUS_COMPLETED); 396 qemu_bh_delete(mis->bh); 397 migration_incoming_state_destroy(); 398 } 399 400 static void process_incoming_migration_co(void *opaque) 401 { 402 MigrationIncomingState *mis = migration_incoming_get_current(); 403 PostcopyState ps; 404 int ret; 405 Error *local_err = NULL; 406 407 assert(mis->from_src_file); 408 mis->migration_incoming_co = qemu_coroutine_self(); 409 mis->largest_page_size = qemu_ram_pagesize_largest(); 410 postcopy_state_set(POSTCOPY_INCOMING_NONE); 411 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE, 412 MIGRATION_STATUS_ACTIVE); 413 ret = qemu_loadvm_state(mis->from_src_file); 414 415 ps = postcopy_state_get(); 416 trace_process_incoming_migration_co_end(ret, ps); 417 if (ps != POSTCOPY_INCOMING_NONE) { 418 if (ps == POSTCOPY_INCOMING_ADVISE) { 419 /* 420 * Where a migration had postcopy enabled (and thus went to advise) 421 * but managed to complete within the precopy period, we can use 422 * the normal exit. 423 */ 424 postcopy_ram_incoming_cleanup(mis); 425 } else if (ret >= 0) { 426 /* 427 * Postcopy was started, cleanup should happen at the end of the 428 * postcopy thread. 429 */ 430 trace_process_incoming_migration_co_postcopy_end_main(); 431 return; 432 } 433 /* Else if something went wrong then just fall out of the normal exit */ 434 } 435 436 /* we get COLO info, and know if we are in COLO mode */ 437 if (!ret && migration_incoming_colo_enabled()) { 438 /* Make sure all file formats flush their mutable metadata */ 439 bdrv_invalidate_cache_all(&local_err); 440 if (local_err) { 441 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 442 MIGRATION_STATUS_FAILED); 443 error_report_err(local_err); 444 exit(EXIT_FAILURE); 445 } 446 447 if (colo_init_ram_cache() < 0) { 448 error_report("Init ram cache failed"); 449 exit(EXIT_FAILURE); 450 } 451 452 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming", 453 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE); 454 mis->have_colo_incoming_thread = true; 455 qemu_coroutine_yield(); 456 457 /* Wait checkpoint incoming thread exit before free resource */ 458 qemu_thread_join(&mis->colo_incoming_thread); 459 /* We hold the global iothread lock, so it is safe here */ 460 colo_release_ram_cache(); 461 } 462 463 if (ret < 0) { 464 Error *local_err = NULL; 465 466 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 467 MIGRATION_STATUS_FAILED); 468 error_report("load of migration failed: %s", strerror(-ret)); 469 qemu_fclose(mis->from_src_file); 470 if (multifd_load_cleanup(&local_err) != 0) { 471 error_report_err(local_err); 472 } 473 exit(EXIT_FAILURE); 474 } 475 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); 476 qemu_bh_schedule(mis->bh); 477 mis->migration_incoming_co = NULL; 478 } 479 480 static void migration_incoming_setup(QEMUFile *f) 481 { 482 MigrationIncomingState *mis = migration_incoming_get_current(); 483 484 if (multifd_load_setup() != 0) { 485 /* We haven't been able to create multifd threads 486 nothing better to do */ 487 exit(EXIT_FAILURE); 488 } 489 490 if (!mis->from_src_file) { 491 mis->from_src_file = f; 492 } 493 qemu_file_set_blocking(f, false); 494 } 495 496 void migration_incoming_process(void) 497 { 498 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL); 499 qemu_coroutine_enter(co); 500 } 501 502 /* Returns true if recovered from a paused migration, otherwise false */ 503 static bool postcopy_try_recover(QEMUFile *f) 504 { 505 MigrationIncomingState *mis = migration_incoming_get_current(); 506 507 if (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) { 508 /* Resumed from a paused postcopy migration */ 509 510 mis->from_src_file = f; 511 /* Postcopy has standalone thread to do vm load */ 512 qemu_file_set_blocking(f, true); 513 514 /* Re-configure the return path */ 515 mis->to_src_file = qemu_file_get_return_path(f); 516 517 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_PAUSED, 518 MIGRATION_STATUS_POSTCOPY_RECOVER); 519 520 /* 521 * Here, we only wake up the main loading thread (while the 522 * fault thread will still be waiting), so that we can receive 523 * commands from source now, and answer it if needed. The 524 * fault thread will be woken up afterwards until we are sure 525 * that source is ready to reply to page requests. 526 */ 527 qemu_sem_post(&mis->postcopy_pause_sem_dst); 528 return true; 529 } 530 531 return false; 532 } 533 534 void migration_fd_process_incoming(QEMUFile *f) 535 { 536 if (postcopy_try_recover(f)) { 537 return; 538 } 539 540 migration_incoming_setup(f); 541 migration_incoming_process(); 542 } 543 544 void migration_ioc_process_incoming(QIOChannel *ioc) 545 { 546 MigrationIncomingState *mis = migration_incoming_get_current(); 547 bool start_migration; 548 549 if (!mis->from_src_file) { 550 /* The first connection (multifd may have multiple) */ 551 QEMUFile *f = qemu_fopen_channel_input(ioc); 552 553 /* If it's a recovery, we're done */ 554 if (postcopy_try_recover(f)) { 555 return; 556 } 557 558 migration_incoming_setup(f); 559 560 /* 561 * Common migration only needs one channel, so we can start 562 * right now. Multifd needs more than one channel, we wait. 563 */ 564 start_migration = !migrate_use_multifd(); 565 } else { 566 /* Multiple connections */ 567 assert(migrate_use_multifd()); 568 start_migration = multifd_recv_new_channel(ioc); 569 } 570 571 if (start_migration) { 572 migration_incoming_process(); 573 } 574 } 575 576 /** 577 * @migration_has_all_channels: We have received all channels that we need 578 * 579 * Returns true when we have got connections to all the channels that 580 * we need for migration. 581 */ 582 bool migration_has_all_channels(void) 583 { 584 MigrationIncomingState *mis = migration_incoming_get_current(); 585 bool all_channels; 586 587 all_channels = multifd_recv_all_channels_created(); 588 589 return all_channels && mis->from_src_file != NULL; 590 } 591 592 /* 593 * Send a 'SHUT' message on the return channel with the given value 594 * to indicate that we've finished with the RP. Non-0 value indicates 595 * error. 596 */ 597 void migrate_send_rp_shut(MigrationIncomingState *mis, 598 uint32_t value) 599 { 600 uint32_t buf; 601 602 buf = cpu_to_be32(value); 603 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); 604 } 605 606 /* 607 * Send a 'PONG' message on the return channel with the given value 608 * (normally in response to a 'PING') 609 */ 610 void migrate_send_rp_pong(MigrationIncomingState *mis, 611 uint32_t value) 612 { 613 uint32_t buf; 614 615 buf = cpu_to_be32(value); 616 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); 617 } 618 619 void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis, 620 char *block_name) 621 { 622 char buf[512]; 623 int len; 624 int64_t res; 625 626 /* 627 * First, we send the header part. It contains only the len of 628 * idstr, and the idstr itself. 629 */ 630 len = strlen(block_name); 631 buf[0] = len; 632 memcpy(buf + 1, block_name, len); 633 634 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) { 635 error_report("%s: MSG_RP_RECV_BITMAP only used for recovery", 636 __func__); 637 return; 638 } 639 640 migrate_send_rp_message(mis, MIG_RP_MSG_RECV_BITMAP, len + 1, buf); 641 642 /* 643 * Next, we dump the received bitmap to the stream. 644 * 645 * TODO: currently we are safe since we are the only one that is 646 * using the to_src_file handle (fault thread is still paused), 647 * and it's ok even not taking the mutex. However the best way is 648 * to take the lock before sending the message header, and release 649 * the lock after sending the bitmap. 650 */ 651 qemu_mutex_lock(&mis->rp_mutex); 652 res = ramblock_recv_bitmap_send(mis->to_src_file, block_name); 653 qemu_mutex_unlock(&mis->rp_mutex); 654 655 trace_migrate_send_rp_recv_bitmap(block_name, res); 656 } 657 658 void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value) 659 { 660 uint32_t buf; 661 662 buf = cpu_to_be32(value); 663 migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf); 664 } 665 666 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) 667 { 668 MigrationCapabilityStatusList *head = NULL; 669 MigrationCapabilityStatusList *caps; 670 MigrationState *s = migrate_get_current(); 671 int i; 672 673 caps = NULL; /* silence compiler warning */ 674 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 675 #ifndef CONFIG_LIVE_BLOCK_MIGRATION 676 if (i == MIGRATION_CAPABILITY_BLOCK) { 677 continue; 678 } 679 #endif 680 if (head == NULL) { 681 head = g_malloc0(sizeof(*caps)); 682 caps = head; 683 } else { 684 caps->next = g_malloc0(sizeof(*caps)); 685 caps = caps->next; 686 } 687 caps->value = 688 g_malloc(sizeof(*caps->value)); 689 caps->value->capability = i; 690 caps->value->state = s->enabled_capabilities[i]; 691 } 692 693 return head; 694 } 695 696 MigrationParameters *qmp_query_migrate_parameters(Error **errp) 697 { 698 MigrationParameters *params; 699 MigrationState *s = migrate_get_current(); 700 701 /* TODO use QAPI_CLONE() instead of duplicating it inline */ 702 params = g_malloc0(sizeof(*params)); 703 params->has_compress_level = true; 704 params->compress_level = s->parameters.compress_level; 705 params->has_compress_threads = true; 706 params->compress_threads = s->parameters.compress_threads; 707 params->has_compress_wait_thread = true; 708 params->compress_wait_thread = s->parameters.compress_wait_thread; 709 params->has_decompress_threads = true; 710 params->decompress_threads = s->parameters.decompress_threads; 711 params->has_cpu_throttle_initial = true; 712 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; 713 params->has_cpu_throttle_increment = true; 714 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; 715 params->has_tls_creds = true; 716 params->tls_creds = g_strdup(s->parameters.tls_creds); 717 params->has_tls_hostname = true; 718 params->tls_hostname = g_strdup(s->parameters.tls_hostname); 719 params->has_max_bandwidth = true; 720 params->max_bandwidth = s->parameters.max_bandwidth; 721 params->has_downtime_limit = true; 722 params->downtime_limit = s->parameters.downtime_limit; 723 params->has_x_checkpoint_delay = true; 724 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay; 725 params->has_block_incremental = true; 726 params->block_incremental = s->parameters.block_incremental; 727 params->has_x_multifd_channels = true; 728 params->x_multifd_channels = s->parameters.x_multifd_channels; 729 params->has_x_multifd_page_count = true; 730 params->x_multifd_page_count = s->parameters.x_multifd_page_count; 731 params->has_xbzrle_cache_size = true; 732 params->xbzrle_cache_size = s->parameters.xbzrle_cache_size; 733 params->has_max_postcopy_bandwidth = true; 734 params->max_postcopy_bandwidth = s->parameters.max_postcopy_bandwidth; 735 params->has_max_cpu_throttle = true; 736 params->max_cpu_throttle = s->parameters.max_cpu_throttle; 737 738 return params; 739 } 740 741 /* 742 * Return true if we're already in the middle of a migration 743 * (i.e. any of the active or setup states) 744 */ 745 bool migration_is_setup_or_active(int state) 746 { 747 switch (state) { 748 case MIGRATION_STATUS_ACTIVE: 749 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 750 case MIGRATION_STATUS_POSTCOPY_PAUSED: 751 case MIGRATION_STATUS_POSTCOPY_RECOVER: 752 case MIGRATION_STATUS_SETUP: 753 case MIGRATION_STATUS_PRE_SWITCHOVER: 754 case MIGRATION_STATUS_DEVICE: 755 return true; 756 757 default: 758 return false; 759 760 } 761 } 762 763 static void populate_ram_info(MigrationInfo *info, MigrationState *s) 764 { 765 info->has_ram = true; 766 info->ram = g_malloc0(sizeof(*info->ram)); 767 info->ram->transferred = ram_counters.transferred; 768 info->ram->total = ram_bytes_total(); 769 info->ram->duplicate = ram_counters.duplicate; 770 /* legacy value. It is not used anymore */ 771 info->ram->skipped = 0; 772 info->ram->normal = ram_counters.normal; 773 info->ram->normal_bytes = ram_counters.normal * 774 qemu_target_page_size(); 775 info->ram->mbps = s->mbps; 776 info->ram->dirty_sync_count = ram_counters.dirty_sync_count; 777 info->ram->postcopy_requests = ram_counters.postcopy_requests; 778 info->ram->page_size = qemu_target_page_size(); 779 info->ram->multifd_bytes = ram_counters.multifd_bytes; 780 781 if (migrate_use_xbzrle()) { 782 info->has_xbzrle_cache = true; 783 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); 784 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); 785 info->xbzrle_cache->bytes = xbzrle_counters.bytes; 786 info->xbzrle_cache->pages = xbzrle_counters.pages; 787 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss; 788 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate; 789 info->xbzrle_cache->overflow = xbzrle_counters.overflow; 790 } 791 792 if (migrate_use_compression()) { 793 info->has_compression = true; 794 info->compression = g_malloc0(sizeof(*info->compression)); 795 info->compression->pages = compression_counters.pages; 796 info->compression->busy = compression_counters.busy; 797 info->compression->busy_rate = compression_counters.busy_rate; 798 info->compression->compressed_size = 799 compression_counters.compressed_size; 800 info->compression->compression_rate = 801 compression_counters.compression_rate; 802 } 803 804 if (cpu_throttle_active()) { 805 info->has_cpu_throttle_percentage = true; 806 info->cpu_throttle_percentage = cpu_throttle_get_percentage(); 807 } 808 809 if (s->state != MIGRATION_STATUS_COMPLETED) { 810 info->ram->remaining = ram_bytes_remaining(); 811 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate; 812 } 813 } 814 815 static void populate_disk_info(MigrationInfo *info) 816 { 817 if (blk_mig_active()) { 818 info->has_disk = true; 819 info->disk = g_malloc0(sizeof(*info->disk)); 820 info->disk->transferred = blk_mig_bytes_transferred(); 821 info->disk->remaining = blk_mig_bytes_remaining(); 822 info->disk->total = blk_mig_bytes_total(); 823 } 824 } 825 826 static void fill_source_migration_info(MigrationInfo *info) 827 { 828 MigrationState *s = migrate_get_current(); 829 830 switch (s->state) { 831 case MIGRATION_STATUS_NONE: 832 /* no migration has happened ever */ 833 /* do not overwrite destination migration status */ 834 return; 835 break; 836 case MIGRATION_STATUS_SETUP: 837 info->has_status = true; 838 info->has_total_time = false; 839 break; 840 case MIGRATION_STATUS_ACTIVE: 841 case MIGRATION_STATUS_CANCELLING: 842 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 843 case MIGRATION_STATUS_PRE_SWITCHOVER: 844 case MIGRATION_STATUS_DEVICE: 845 case MIGRATION_STATUS_POSTCOPY_PAUSED: 846 case MIGRATION_STATUS_POSTCOPY_RECOVER: 847 /* TODO add some postcopy stats */ 848 info->has_status = true; 849 info->has_total_time = true; 850 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) 851 - s->start_time; 852 info->has_expected_downtime = true; 853 info->expected_downtime = s->expected_downtime; 854 info->has_setup_time = true; 855 info->setup_time = s->setup_time; 856 857 populate_ram_info(info, s); 858 populate_disk_info(info); 859 break; 860 case MIGRATION_STATUS_COLO: 861 info->has_status = true; 862 /* TODO: display COLO specific information (checkpoint info etc.) */ 863 break; 864 case MIGRATION_STATUS_COMPLETED: 865 info->has_status = true; 866 info->has_total_time = true; 867 info->total_time = s->total_time; 868 info->has_downtime = true; 869 info->downtime = s->downtime; 870 info->has_setup_time = true; 871 info->setup_time = s->setup_time; 872 873 populate_ram_info(info, s); 874 break; 875 case MIGRATION_STATUS_FAILED: 876 info->has_status = true; 877 if (s->error) { 878 info->has_error_desc = true; 879 info->error_desc = g_strdup(error_get_pretty(s->error)); 880 } 881 break; 882 case MIGRATION_STATUS_CANCELLED: 883 info->has_status = true; 884 break; 885 } 886 info->status = s->state; 887 } 888 889 /** 890 * @migration_caps_check - check capability validity 891 * 892 * @cap_list: old capability list, array of bool 893 * @params: new capabilities to be applied soon 894 * @errp: set *errp if the check failed, with reason 895 * 896 * Returns true if check passed, otherwise false. 897 */ 898 static bool migrate_caps_check(bool *cap_list, 899 MigrationCapabilityStatusList *params, 900 Error **errp) 901 { 902 MigrationCapabilityStatusList *cap; 903 bool old_postcopy_cap; 904 MigrationIncomingState *mis = migration_incoming_get_current(); 905 906 old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 907 908 for (cap = params; cap; cap = cap->next) { 909 cap_list[cap->value->capability] = cap->value->state; 910 } 911 912 #ifndef CONFIG_LIVE_BLOCK_MIGRATION 913 if (cap_list[MIGRATION_CAPABILITY_BLOCK]) { 914 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) " 915 "block migration"); 916 error_append_hint(errp, "Use drive_mirror+NBD instead.\n"); 917 return false; 918 } 919 #endif 920 921 if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) { 922 if (cap_list[MIGRATION_CAPABILITY_COMPRESS]) { 923 /* The decompression threads asynchronously write into RAM 924 * rather than use the atomic copies needed to avoid 925 * userfaulting. It should be possible to fix the decompression 926 * threads for compatibility in future. 927 */ 928 error_setg(errp, "Postcopy is not currently compatible " 929 "with compression"); 930 return false; 931 } 932 933 /* This check is reasonably expensive, so only when it's being 934 * set the first time, also it's only the destination that needs 935 * special support. 936 */ 937 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) && 938 !postcopy_ram_supported_by_host(mis)) { 939 /* postcopy_ram_supported_by_host will have emitted a more 940 * detailed message 941 */ 942 error_setg(errp, "Postcopy is not supported"); 943 return false; 944 } 945 } 946 947 return true; 948 } 949 950 static void fill_destination_migration_info(MigrationInfo *info) 951 { 952 MigrationIncomingState *mis = migration_incoming_get_current(); 953 954 switch (mis->state) { 955 case MIGRATION_STATUS_NONE: 956 return; 957 break; 958 case MIGRATION_STATUS_SETUP: 959 case MIGRATION_STATUS_CANCELLING: 960 case MIGRATION_STATUS_CANCELLED: 961 case MIGRATION_STATUS_ACTIVE: 962 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 963 case MIGRATION_STATUS_POSTCOPY_PAUSED: 964 case MIGRATION_STATUS_POSTCOPY_RECOVER: 965 case MIGRATION_STATUS_FAILED: 966 case MIGRATION_STATUS_COLO: 967 info->has_status = true; 968 break; 969 case MIGRATION_STATUS_COMPLETED: 970 info->has_status = true; 971 fill_destination_postcopy_migration_info(info); 972 break; 973 } 974 info->status = mis->state; 975 } 976 977 MigrationInfo *qmp_query_migrate(Error **errp) 978 { 979 MigrationInfo *info = g_malloc0(sizeof(*info)); 980 981 fill_destination_migration_info(info); 982 fill_source_migration_info(info); 983 984 return info; 985 } 986 987 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 988 Error **errp) 989 { 990 MigrationState *s = migrate_get_current(); 991 MigrationCapabilityStatusList *cap; 992 bool cap_list[MIGRATION_CAPABILITY__MAX]; 993 994 if (migration_is_setup_or_active(s->state)) { 995 error_setg(errp, QERR_MIGRATION_ACTIVE); 996 return; 997 } 998 999 memcpy(cap_list, s->enabled_capabilities, sizeof(cap_list)); 1000 if (!migrate_caps_check(cap_list, params, errp)) { 1001 return; 1002 } 1003 1004 for (cap = params; cap; cap = cap->next) { 1005 s->enabled_capabilities[cap->value->capability] = cap->value->state; 1006 } 1007 } 1008 1009 /* 1010 * Check whether the parameters are valid. Error will be put into errp 1011 * (if provided). Return true if valid, otherwise false. 1012 */ 1013 static bool migrate_params_check(MigrationParameters *params, Error **errp) 1014 { 1015 if (params->has_compress_level && 1016 (params->compress_level > 9)) { 1017 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level", 1018 "is invalid, it should be in the range of 0 to 9"); 1019 return false; 1020 } 1021 1022 if (params->has_compress_threads && (params->compress_threads < 1)) { 1023 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1024 "compress_threads", 1025 "is invalid, it should be in the range of 1 to 255"); 1026 return false; 1027 } 1028 1029 if (params->has_decompress_threads && (params->decompress_threads < 1)) { 1030 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1031 "decompress_threads", 1032 "is invalid, it should be in the range of 1 to 255"); 1033 return false; 1034 } 1035 1036 if (params->has_cpu_throttle_initial && 1037 (params->cpu_throttle_initial < 1 || 1038 params->cpu_throttle_initial > 99)) { 1039 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1040 "cpu_throttle_initial", 1041 "an integer in the range of 1 to 99"); 1042 return false; 1043 } 1044 1045 if (params->has_cpu_throttle_increment && 1046 (params->cpu_throttle_increment < 1 || 1047 params->cpu_throttle_increment > 99)) { 1048 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1049 "cpu_throttle_increment", 1050 "an integer in the range of 1 to 99"); 1051 return false; 1052 } 1053 1054 if (params->has_max_bandwidth && (params->max_bandwidth > SIZE_MAX)) { 1055 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the" 1056 " range of 0 to %zu bytes/second", SIZE_MAX); 1057 return false; 1058 } 1059 1060 if (params->has_downtime_limit && 1061 (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) { 1062 error_setg(errp, "Parameter 'downtime_limit' expects an integer in " 1063 "the range of 0 to %d milliseconds", 1064 MAX_MIGRATE_DOWNTIME); 1065 return false; 1066 } 1067 1068 /* x_checkpoint_delay is now always positive */ 1069 1070 if (params->has_x_multifd_channels && (params->x_multifd_channels < 1)) { 1071 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1072 "multifd_channels", 1073 "is invalid, it should be in the range of 1 to 255"); 1074 return false; 1075 } 1076 if (params->has_x_multifd_page_count && 1077 (params->x_multifd_page_count < 1 || 1078 params->x_multifd_page_count > 10000)) { 1079 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1080 "multifd_page_count", 1081 "is invalid, it should be in the range of 1 to 10000"); 1082 return false; 1083 } 1084 1085 if (params->has_xbzrle_cache_size && 1086 (params->xbzrle_cache_size < qemu_target_page_size() || 1087 !is_power_of_2(params->xbzrle_cache_size))) { 1088 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1089 "xbzrle_cache_size", 1090 "is invalid, it should be bigger than target page size" 1091 " and a power of two"); 1092 return false; 1093 } 1094 1095 if (params->has_max_cpu_throttle && 1096 (params->max_cpu_throttle < params->cpu_throttle_initial || 1097 params->max_cpu_throttle > 99)) { 1098 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, 1099 "max_cpu_throttle", 1100 "an integer in the range of cpu_throttle_initial to 99"); 1101 return false; 1102 } 1103 1104 return true; 1105 } 1106 1107 static void migrate_params_test_apply(MigrateSetParameters *params, 1108 MigrationParameters *dest) 1109 { 1110 *dest = migrate_get_current()->parameters; 1111 1112 /* TODO use QAPI_CLONE() instead of duplicating it inline */ 1113 1114 if (params->has_compress_level) { 1115 dest->compress_level = params->compress_level; 1116 } 1117 1118 if (params->has_compress_threads) { 1119 dest->compress_threads = params->compress_threads; 1120 } 1121 1122 if (params->has_compress_wait_thread) { 1123 dest->compress_wait_thread = params->compress_wait_thread; 1124 } 1125 1126 if (params->has_decompress_threads) { 1127 dest->decompress_threads = params->decompress_threads; 1128 } 1129 1130 if (params->has_cpu_throttle_initial) { 1131 dest->cpu_throttle_initial = params->cpu_throttle_initial; 1132 } 1133 1134 if (params->has_cpu_throttle_increment) { 1135 dest->cpu_throttle_increment = params->cpu_throttle_increment; 1136 } 1137 1138 if (params->has_tls_creds) { 1139 assert(params->tls_creds->type == QTYPE_QSTRING); 1140 dest->tls_creds = g_strdup(params->tls_creds->u.s); 1141 } 1142 1143 if (params->has_tls_hostname) { 1144 assert(params->tls_hostname->type == QTYPE_QSTRING); 1145 dest->tls_hostname = g_strdup(params->tls_hostname->u.s); 1146 } 1147 1148 if (params->has_max_bandwidth) { 1149 dest->max_bandwidth = params->max_bandwidth; 1150 } 1151 1152 if (params->has_downtime_limit) { 1153 dest->downtime_limit = params->downtime_limit; 1154 } 1155 1156 if (params->has_x_checkpoint_delay) { 1157 dest->x_checkpoint_delay = params->x_checkpoint_delay; 1158 } 1159 1160 if (params->has_block_incremental) { 1161 dest->block_incremental = params->block_incremental; 1162 } 1163 if (params->has_x_multifd_channels) { 1164 dest->x_multifd_channels = params->x_multifd_channels; 1165 } 1166 if (params->has_x_multifd_page_count) { 1167 dest->x_multifd_page_count = params->x_multifd_page_count; 1168 } 1169 if (params->has_xbzrle_cache_size) { 1170 dest->xbzrle_cache_size = params->xbzrle_cache_size; 1171 } 1172 if (params->has_max_postcopy_bandwidth) { 1173 dest->max_postcopy_bandwidth = params->max_postcopy_bandwidth; 1174 } 1175 if (params->has_max_cpu_throttle) { 1176 dest->max_cpu_throttle = params->max_cpu_throttle; 1177 } 1178 } 1179 1180 static void migrate_params_apply(MigrateSetParameters *params, Error **errp) 1181 { 1182 MigrationState *s = migrate_get_current(); 1183 1184 /* TODO use QAPI_CLONE() instead of duplicating it inline */ 1185 1186 if (params->has_compress_level) { 1187 s->parameters.compress_level = params->compress_level; 1188 } 1189 1190 if (params->has_compress_threads) { 1191 s->parameters.compress_threads = params->compress_threads; 1192 } 1193 1194 if (params->has_compress_wait_thread) { 1195 s->parameters.compress_wait_thread = params->compress_wait_thread; 1196 } 1197 1198 if (params->has_decompress_threads) { 1199 s->parameters.decompress_threads = params->decompress_threads; 1200 } 1201 1202 if (params->has_cpu_throttle_initial) { 1203 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial; 1204 } 1205 1206 if (params->has_cpu_throttle_increment) { 1207 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; 1208 } 1209 1210 if (params->has_tls_creds) { 1211 g_free(s->parameters.tls_creds); 1212 assert(params->tls_creds->type == QTYPE_QSTRING); 1213 s->parameters.tls_creds = g_strdup(params->tls_creds->u.s); 1214 } 1215 1216 if (params->has_tls_hostname) { 1217 g_free(s->parameters.tls_hostname); 1218 assert(params->tls_hostname->type == QTYPE_QSTRING); 1219 s->parameters.tls_hostname = g_strdup(params->tls_hostname->u.s); 1220 } 1221 1222 if (params->has_max_bandwidth) { 1223 s->parameters.max_bandwidth = params->max_bandwidth; 1224 if (s->to_dst_file) { 1225 qemu_file_set_rate_limit(s->to_dst_file, 1226 s->parameters.max_bandwidth / XFER_LIMIT_RATIO); 1227 } 1228 } 1229 1230 if (params->has_downtime_limit) { 1231 s->parameters.downtime_limit = params->downtime_limit; 1232 } 1233 1234 if (params->has_x_checkpoint_delay) { 1235 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay; 1236 if (migration_in_colo_state()) { 1237 colo_checkpoint_notify(s); 1238 } 1239 } 1240 1241 if (params->has_block_incremental) { 1242 s->parameters.block_incremental = params->block_incremental; 1243 } 1244 if (params->has_x_multifd_channels) { 1245 s->parameters.x_multifd_channels = params->x_multifd_channels; 1246 } 1247 if (params->has_x_multifd_page_count) { 1248 s->parameters.x_multifd_page_count = params->x_multifd_page_count; 1249 } 1250 if (params->has_xbzrle_cache_size) { 1251 s->parameters.xbzrle_cache_size = params->xbzrle_cache_size; 1252 xbzrle_cache_resize(params->xbzrle_cache_size, errp); 1253 } 1254 if (params->has_max_postcopy_bandwidth) { 1255 s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth; 1256 } 1257 if (params->has_max_cpu_throttle) { 1258 s->parameters.max_cpu_throttle = params->max_cpu_throttle; 1259 } 1260 } 1261 1262 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) 1263 { 1264 MigrationParameters tmp; 1265 1266 /* TODO Rewrite "" to null instead */ 1267 if (params->has_tls_creds 1268 && params->tls_creds->type == QTYPE_QNULL) { 1269 qobject_unref(params->tls_creds->u.n); 1270 params->tls_creds->type = QTYPE_QSTRING; 1271 params->tls_creds->u.s = strdup(""); 1272 } 1273 /* TODO Rewrite "" to null instead */ 1274 if (params->has_tls_hostname 1275 && params->tls_hostname->type == QTYPE_QNULL) { 1276 qobject_unref(params->tls_hostname->u.n); 1277 params->tls_hostname->type = QTYPE_QSTRING; 1278 params->tls_hostname->u.s = strdup(""); 1279 } 1280 1281 migrate_params_test_apply(params, &tmp); 1282 1283 if (!migrate_params_check(&tmp, errp)) { 1284 /* Invalid parameter */ 1285 return; 1286 } 1287 1288 migrate_params_apply(params, errp); 1289 } 1290 1291 1292 void qmp_migrate_start_postcopy(Error **errp) 1293 { 1294 MigrationState *s = migrate_get_current(); 1295 1296 if (!migrate_postcopy()) { 1297 error_setg(errp, "Enable postcopy with migrate_set_capability before" 1298 " the start of migration"); 1299 return; 1300 } 1301 1302 if (s->state == MIGRATION_STATUS_NONE) { 1303 error_setg(errp, "Postcopy must be started after migration has been" 1304 " started"); 1305 return; 1306 } 1307 /* 1308 * we don't error if migration has finished since that would be racy 1309 * with issuing this command. 1310 */ 1311 atomic_set(&s->start_postcopy, true); 1312 } 1313 1314 /* shared migration helpers */ 1315 1316 void migrate_set_state(int *state, int old_state, int new_state) 1317 { 1318 assert(new_state < MIGRATION_STATUS__MAX); 1319 if (atomic_cmpxchg(state, old_state, new_state) == old_state) { 1320 trace_migrate_set_state(MigrationStatus_str(new_state)); 1321 migrate_generate_event(new_state); 1322 } 1323 } 1324 1325 static MigrationCapabilityStatusList *migrate_cap_add( 1326 MigrationCapabilityStatusList *list, 1327 MigrationCapability index, 1328 bool state) 1329 { 1330 MigrationCapabilityStatusList *cap; 1331 1332 cap = g_new0(MigrationCapabilityStatusList, 1); 1333 cap->value = g_new0(MigrationCapabilityStatus, 1); 1334 cap->value->capability = index; 1335 cap->value->state = state; 1336 cap->next = list; 1337 1338 return cap; 1339 } 1340 1341 void migrate_set_block_enabled(bool value, Error **errp) 1342 { 1343 MigrationCapabilityStatusList *cap; 1344 1345 cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value); 1346 qmp_migrate_set_capabilities(cap, errp); 1347 qapi_free_MigrationCapabilityStatusList(cap); 1348 } 1349 1350 static void migrate_set_block_incremental(MigrationState *s, bool value) 1351 { 1352 s->parameters.block_incremental = value; 1353 } 1354 1355 static void block_cleanup_parameters(MigrationState *s) 1356 { 1357 if (s->must_remove_block_options) { 1358 /* setting to false can never fail */ 1359 migrate_set_block_enabled(false, &error_abort); 1360 migrate_set_block_incremental(s, false); 1361 s->must_remove_block_options = false; 1362 } 1363 } 1364 1365 static void migrate_fd_cleanup(void *opaque) 1366 { 1367 MigrationState *s = opaque; 1368 1369 qemu_bh_delete(s->cleanup_bh); 1370 s->cleanup_bh = NULL; 1371 1372 qemu_savevm_state_cleanup(); 1373 1374 if (s->to_dst_file) { 1375 Error *local_err = NULL; 1376 QEMUFile *tmp; 1377 1378 trace_migrate_fd_cleanup(); 1379 qemu_mutex_unlock_iothread(); 1380 if (s->migration_thread_running) { 1381 qemu_thread_join(&s->thread); 1382 s->migration_thread_running = false; 1383 } 1384 qemu_mutex_lock_iothread(); 1385 1386 if (multifd_save_cleanup(&local_err) != 0) { 1387 error_report_err(local_err); 1388 } 1389 qemu_mutex_lock(&s->qemu_file_lock); 1390 tmp = s->to_dst_file; 1391 s->to_dst_file = NULL; 1392 qemu_mutex_unlock(&s->qemu_file_lock); 1393 /* 1394 * Close the file handle without the lock to make sure the 1395 * critical section won't block for long. 1396 */ 1397 qemu_fclose(tmp); 1398 } 1399 1400 assert((s->state != MIGRATION_STATUS_ACTIVE) && 1401 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE)); 1402 1403 if (s->state == MIGRATION_STATUS_CANCELLING) { 1404 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING, 1405 MIGRATION_STATUS_CANCELLED); 1406 } 1407 1408 if (s->error) { 1409 /* It is used on info migrate. We can't free it */ 1410 error_report_err(error_copy(s->error)); 1411 } 1412 notifier_list_notify(&migration_state_notifiers, s); 1413 block_cleanup_parameters(s); 1414 } 1415 1416 void migrate_set_error(MigrationState *s, const Error *error) 1417 { 1418 qemu_mutex_lock(&s->error_mutex); 1419 if (!s->error) { 1420 s->error = error_copy(error); 1421 } 1422 qemu_mutex_unlock(&s->error_mutex); 1423 } 1424 1425 void migrate_fd_error(MigrationState *s, const Error *error) 1426 { 1427 trace_migrate_fd_error(error_get_pretty(error)); 1428 assert(s->to_dst_file == NULL); 1429 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1430 MIGRATION_STATUS_FAILED); 1431 migrate_set_error(s, error); 1432 } 1433 1434 static void migrate_fd_cancel(MigrationState *s) 1435 { 1436 int old_state ; 1437 QEMUFile *f = migrate_get_current()->to_dst_file; 1438 trace_migrate_fd_cancel(); 1439 1440 if (s->rp_state.from_dst_file) { 1441 /* shutdown the rp socket, so causing the rp thread to shutdown */ 1442 qemu_file_shutdown(s->rp_state.from_dst_file); 1443 } 1444 1445 do { 1446 old_state = s->state; 1447 if (!migration_is_setup_or_active(old_state)) { 1448 break; 1449 } 1450 /* If the migration is paused, kick it out of the pause */ 1451 if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) { 1452 qemu_sem_post(&s->pause_sem); 1453 } 1454 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING); 1455 } while (s->state != MIGRATION_STATUS_CANCELLING); 1456 1457 /* 1458 * If we're unlucky the migration code might be stuck somewhere in a 1459 * send/write while the network has failed and is waiting to timeout; 1460 * if we've got shutdown(2) available then we can force it to quit. 1461 * The outgoing qemu file gets closed in migrate_fd_cleanup that is 1462 * called in a bh, so there is no race against this cancel. 1463 */ 1464 if (s->state == MIGRATION_STATUS_CANCELLING && f) { 1465 qemu_file_shutdown(f); 1466 } 1467 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) { 1468 Error *local_err = NULL; 1469 1470 bdrv_invalidate_cache_all(&local_err); 1471 if (local_err) { 1472 error_report_err(local_err); 1473 } else { 1474 s->block_inactive = false; 1475 } 1476 } 1477 } 1478 1479 void add_migration_state_change_notifier(Notifier *notify) 1480 { 1481 notifier_list_add(&migration_state_notifiers, notify); 1482 } 1483 1484 void remove_migration_state_change_notifier(Notifier *notify) 1485 { 1486 notifier_remove(notify); 1487 } 1488 1489 bool migration_in_setup(MigrationState *s) 1490 { 1491 return s->state == MIGRATION_STATUS_SETUP; 1492 } 1493 1494 bool migration_has_finished(MigrationState *s) 1495 { 1496 return s->state == MIGRATION_STATUS_COMPLETED; 1497 } 1498 1499 bool migration_has_failed(MigrationState *s) 1500 { 1501 return (s->state == MIGRATION_STATUS_CANCELLED || 1502 s->state == MIGRATION_STATUS_FAILED); 1503 } 1504 1505 bool migration_in_postcopy(void) 1506 { 1507 MigrationState *s = migrate_get_current(); 1508 1509 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 1510 } 1511 1512 bool migration_in_postcopy_after_devices(MigrationState *s) 1513 { 1514 return migration_in_postcopy() && s->postcopy_after_devices; 1515 } 1516 1517 bool migration_is_idle(void) 1518 { 1519 MigrationState *s = migrate_get_current(); 1520 1521 switch (s->state) { 1522 case MIGRATION_STATUS_NONE: 1523 case MIGRATION_STATUS_CANCELLED: 1524 case MIGRATION_STATUS_COMPLETED: 1525 case MIGRATION_STATUS_FAILED: 1526 return true; 1527 case MIGRATION_STATUS_SETUP: 1528 case MIGRATION_STATUS_CANCELLING: 1529 case MIGRATION_STATUS_ACTIVE: 1530 case MIGRATION_STATUS_POSTCOPY_ACTIVE: 1531 case MIGRATION_STATUS_COLO: 1532 case MIGRATION_STATUS_PRE_SWITCHOVER: 1533 case MIGRATION_STATUS_DEVICE: 1534 return false; 1535 case MIGRATION_STATUS__MAX: 1536 g_assert_not_reached(); 1537 } 1538 1539 return false; 1540 } 1541 1542 void migrate_init(MigrationState *s) 1543 { 1544 /* 1545 * Reinitialise all migration state, except 1546 * parameters/capabilities that the user set, and 1547 * locks. 1548 */ 1549 s->bytes_xfer = 0; 1550 s->xfer_limit = 0; 1551 s->cleanup_bh = 0; 1552 s->to_dst_file = NULL; 1553 s->state = MIGRATION_STATUS_NONE; 1554 s->rp_state.from_dst_file = NULL; 1555 s->rp_state.error = false; 1556 s->mbps = 0.0; 1557 s->downtime = 0; 1558 s->expected_downtime = 0; 1559 s->setup_time = 0; 1560 s->start_postcopy = false; 1561 s->postcopy_after_devices = false; 1562 s->migration_thread_running = false; 1563 error_free(s->error); 1564 s->error = NULL; 1565 1566 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); 1567 1568 s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 1569 s->total_time = 0; 1570 s->vm_was_running = false; 1571 s->iteration_initial_bytes = 0; 1572 s->threshold_size = 0; 1573 } 1574 1575 static GSList *migration_blockers; 1576 1577 int migrate_add_blocker(Error *reason, Error **errp) 1578 { 1579 if (migrate_get_current()->only_migratable) { 1580 error_propagate_prepend(errp, error_copy(reason), 1581 "disallowing migration blocker " 1582 "(--only_migratable) for: "); 1583 return -EACCES; 1584 } 1585 1586 if (migration_is_idle()) { 1587 migration_blockers = g_slist_prepend(migration_blockers, reason); 1588 return 0; 1589 } 1590 1591 error_propagate_prepend(errp, error_copy(reason), 1592 "disallowing migration blocker " 1593 "(migration in progress) for: "); 1594 return -EBUSY; 1595 } 1596 1597 void migrate_del_blocker(Error *reason) 1598 { 1599 migration_blockers = g_slist_remove(migration_blockers, reason); 1600 } 1601 1602 void qmp_migrate_incoming(const char *uri, Error **errp) 1603 { 1604 Error *local_err = NULL; 1605 static bool once = true; 1606 1607 if (!deferred_incoming) { 1608 error_setg(errp, "For use with '-incoming defer'"); 1609 return; 1610 } 1611 if (!once) { 1612 error_setg(errp, "The incoming migration has already been started"); 1613 } 1614 1615 qemu_start_incoming_migration(uri, &local_err); 1616 1617 if (local_err) { 1618 error_propagate(errp, local_err); 1619 return; 1620 } 1621 1622 once = false; 1623 } 1624 1625 void qmp_migrate_recover(const char *uri, Error **errp) 1626 { 1627 MigrationIncomingState *mis = migration_incoming_get_current(); 1628 1629 if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) { 1630 error_setg(errp, "Migrate recover can only be run " 1631 "when postcopy is paused."); 1632 return; 1633 } 1634 1635 if (atomic_cmpxchg(&mis->postcopy_recover_triggered, 1636 false, true) == true) { 1637 error_setg(errp, "Migrate recovery is triggered already"); 1638 return; 1639 } 1640 1641 /* 1642 * Note that this call will never start a real migration; it will 1643 * only re-setup the migration stream and poke existing migration 1644 * to continue using that newly established channel. 1645 */ 1646 qemu_start_incoming_migration(uri, errp); 1647 } 1648 1649 void qmp_migrate_pause(Error **errp) 1650 { 1651 MigrationState *ms = migrate_get_current(); 1652 MigrationIncomingState *mis = migration_incoming_get_current(); 1653 int ret; 1654 1655 if (ms->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1656 /* Source side, during postcopy */ 1657 qemu_mutex_lock(&ms->qemu_file_lock); 1658 ret = qemu_file_shutdown(ms->to_dst_file); 1659 qemu_mutex_unlock(&ms->qemu_file_lock); 1660 if (ret) { 1661 error_setg(errp, "Failed to pause source migration"); 1662 } 1663 return; 1664 } 1665 1666 if (mis->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 1667 ret = qemu_file_shutdown(mis->from_src_file); 1668 if (ret) { 1669 error_setg(errp, "Failed to pause destination migration"); 1670 } 1671 return; 1672 } 1673 1674 error_setg(errp, "migrate-pause is currently only supported " 1675 "during postcopy-active state"); 1676 } 1677 1678 bool migration_is_blocked(Error **errp) 1679 { 1680 if (qemu_savevm_state_blocked(errp)) { 1681 return true; 1682 } 1683 1684 if (migration_blockers) { 1685 error_propagate(errp, error_copy(migration_blockers->data)); 1686 return true; 1687 } 1688 1689 return false; 1690 } 1691 1692 /* Returns true if continue to migrate, or false if error detected */ 1693 static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc, 1694 bool resume, Error **errp) 1695 { 1696 Error *local_err = NULL; 1697 1698 if (resume) { 1699 if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) { 1700 error_setg(errp, "Cannot resume if there is no " 1701 "paused migration"); 1702 return false; 1703 } 1704 1705 /* 1706 * Postcopy recovery won't work well with release-ram 1707 * capability since release-ram will drop the page buffer as 1708 * long as the page is put into the send buffer. So if there 1709 * is a network failure happened, any page buffers that have 1710 * not yet reached the destination VM but have already been 1711 * sent from the source VM will be lost forever. Let's refuse 1712 * the client from resuming such a postcopy migration. 1713 * Luckily release-ram was designed to only be used when src 1714 * and destination VMs are on the same host, so it should be 1715 * fine. 1716 */ 1717 if (migrate_release_ram()) { 1718 error_setg(errp, "Postcopy recovery cannot work " 1719 "when release-ram capability is set"); 1720 return false; 1721 } 1722 1723 /* This is a resume, skip init status */ 1724 return true; 1725 } 1726 1727 if (migration_is_setup_or_active(s->state) || 1728 s->state == MIGRATION_STATUS_CANCELLING || 1729 s->state == MIGRATION_STATUS_COLO) { 1730 error_setg(errp, QERR_MIGRATION_ACTIVE); 1731 return false; 1732 } 1733 1734 if (runstate_check(RUN_STATE_INMIGRATE)) { 1735 error_setg(errp, "Guest is waiting for an incoming migration"); 1736 return false; 1737 } 1738 1739 if (migration_is_blocked(errp)) { 1740 return false; 1741 } 1742 1743 if (blk || blk_inc) { 1744 if (migrate_use_block() || migrate_use_block_incremental()) { 1745 error_setg(errp, "Command options are incompatible with " 1746 "current migration capabilities"); 1747 return false; 1748 } 1749 migrate_set_block_enabled(true, &local_err); 1750 if (local_err) { 1751 error_propagate(errp, local_err); 1752 return false; 1753 } 1754 s->must_remove_block_options = true; 1755 } 1756 1757 if (blk_inc) { 1758 migrate_set_block_incremental(s, true); 1759 } 1760 1761 migrate_init(s); 1762 1763 return true; 1764 } 1765 1766 void qmp_migrate(const char *uri, bool has_blk, bool blk, 1767 bool has_inc, bool inc, bool has_detach, bool detach, 1768 bool has_resume, bool resume, Error **errp) 1769 { 1770 Error *local_err = NULL; 1771 MigrationState *s = migrate_get_current(); 1772 const char *p; 1773 1774 if (!migrate_prepare(s, has_blk && blk, has_inc && inc, 1775 has_resume && resume, errp)) { 1776 /* Error detected, put into errp */ 1777 return; 1778 } 1779 1780 if (strstart(uri, "tcp:", &p)) { 1781 tcp_start_outgoing_migration(s, p, &local_err); 1782 #ifdef CONFIG_RDMA 1783 } else if (strstart(uri, "rdma:", &p)) { 1784 rdma_start_outgoing_migration(s, p, &local_err); 1785 #endif 1786 } else if (strstart(uri, "exec:", &p)) { 1787 exec_start_outgoing_migration(s, p, &local_err); 1788 } else if (strstart(uri, "unix:", &p)) { 1789 unix_start_outgoing_migration(s, p, &local_err); 1790 } else if (strstart(uri, "fd:", &p)) { 1791 fd_start_outgoing_migration(s, p, &local_err); 1792 } else { 1793 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", 1794 "a valid migration protocol"); 1795 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 1796 MIGRATION_STATUS_FAILED); 1797 block_cleanup_parameters(s); 1798 return; 1799 } 1800 1801 if (local_err) { 1802 migrate_fd_error(s, local_err); 1803 error_propagate(errp, local_err); 1804 return; 1805 } 1806 } 1807 1808 void qmp_migrate_cancel(Error **errp) 1809 { 1810 migrate_fd_cancel(migrate_get_current()); 1811 } 1812 1813 void qmp_migrate_continue(MigrationStatus state, Error **errp) 1814 { 1815 MigrationState *s = migrate_get_current(); 1816 if (s->state != state) { 1817 error_setg(errp, "Migration not in expected state: %s", 1818 MigrationStatus_str(s->state)); 1819 return; 1820 } 1821 qemu_sem_post(&s->pause_sem); 1822 } 1823 1824 void qmp_migrate_set_cache_size(int64_t value, Error **errp) 1825 { 1826 MigrateSetParameters p = { 1827 .has_xbzrle_cache_size = true, 1828 .xbzrle_cache_size = value, 1829 }; 1830 1831 qmp_migrate_set_parameters(&p, errp); 1832 } 1833 1834 int64_t qmp_query_migrate_cache_size(Error **errp) 1835 { 1836 return migrate_xbzrle_cache_size(); 1837 } 1838 1839 void qmp_migrate_set_speed(int64_t value, Error **errp) 1840 { 1841 MigrateSetParameters p = { 1842 .has_max_bandwidth = true, 1843 .max_bandwidth = value, 1844 }; 1845 1846 qmp_migrate_set_parameters(&p, errp); 1847 } 1848 1849 void qmp_migrate_set_downtime(double value, Error **errp) 1850 { 1851 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) { 1852 error_setg(errp, "Parameter 'downtime_limit' expects an integer in " 1853 "the range of 0 to %d seconds", 1854 MAX_MIGRATE_DOWNTIME_SECONDS); 1855 return; 1856 } 1857 1858 value *= 1000; /* Convert to milliseconds */ 1859 value = MAX(0, MIN(INT64_MAX, value)); 1860 1861 MigrateSetParameters p = { 1862 .has_downtime_limit = true, 1863 .downtime_limit = value, 1864 }; 1865 1866 qmp_migrate_set_parameters(&p, errp); 1867 } 1868 1869 bool migrate_release_ram(void) 1870 { 1871 MigrationState *s; 1872 1873 s = migrate_get_current(); 1874 1875 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM]; 1876 } 1877 1878 bool migrate_postcopy_ram(void) 1879 { 1880 MigrationState *s; 1881 1882 s = migrate_get_current(); 1883 1884 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM]; 1885 } 1886 1887 bool migrate_postcopy(void) 1888 { 1889 return migrate_postcopy_ram() || migrate_dirty_bitmaps(); 1890 } 1891 1892 bool migrate_auto_converge(void) 1893 { 1894 MigrationState *s; 1895 1896 s = migrate_get_current(); 1897 1898 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; 1899 } 1900 1901 bool migrate_zero_blocks(void) 1902 { 1903 MigrationState *s; 1904 1905 s = migrate_get_current(); 1906 1907 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; 1908 } 1909 1910 bool migrate_postcopy_blocktime(void) 1911 { 1912 MigrationState *s; 1913 1914 s = migrate_get_current(); 1915 1916 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME]; 1917 } 1918 1919 bool migrate_use_compression(void) 1920 { 1921 MigrationState *s; 1922 1923 s = migrate_get_current(); 1924 1925 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS]; 1926 } 1927 1928 int migrate_compress_level(void) 1929 { 1930 MigrationState *s; 1931 1932 s = migrate_get_current(); 1933 1934 return s->parameters.compress_level; 1935 } 1936 1937 int migrate_compress_threads(void) 1938 { 1939 MigrationState *s; 1940 1941 s = migrate_get_current(); 1942 1943 return s->parameters.compress_threads; 1944 } 1945 1946 int migrate_compress_wait_thread(void) 1947 { 1948 MigrationState *s; 1949 1950 s = migrate_get_current(); 1951 1952 return s->parameters.compress_wait_thread; 1953 } 1954 1955 int migrate_decompress_threads(void) 1956 { 1957 MigrationState *s; 1958 1959 s = migrate_get_current(); 1960 1961 return s->parameters.decompress_threads; 1962 } 1963 1964 bool migrate_dirty_bitmaps(void) 1965 { 1966 MigrationState *s; 1967 1968 s = migrate_get_current(); 1969 1970 return s->enabled_capabilities[MIGRATION_CAPABILITY_DIRTY_BITMAPS]; 1971 } 1972 1973 bool migrate_use_events(void) 1974 { 1975 MigrationState *s; 1976 1977 s = migrate_get_current(); 1978 1979 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS]; 1980 } 1981 1982 bool migrate_use_multifd(void) 1983 { 1984 MigrationState *s; 1985 1986 s = migrate_get_current(); 1987 1988 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD]; 1989 } 1990 1991 bool migrate_pause_before_switchover(void) 1992 { 1993 MigrationState *s; 1994 1995 s = migrate_get_current(); 1996 1997 return s->enabled_capabilities[ 1998 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER]; 1999 } 2000 2001 int migrate_multifd_channels(void) 2002 { 2003 MigrationState *s; 2004 2005 s = migrate_get_current(); 2006 2007 return s->parameters.x_multifd_channels; 2008 } 2009 2010 int migrate_multifd_page_count(void) 2011 { 2012 MigrationState *s; 2013 2014 s = migrate_get_current(); 2015 2016 return s->parameters.x_multifd_page_count; 2017 } 2018 2019 int migrate_use_xbzrle(void) 2020 { 2021 MigrationState *s; 2022 2023 s = migrate_get_current(); 2024 2025 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; 2026 } 2027 2028 int64_t migrate_xbzrle_cache_size(void) 2029 { 2030 MigrationState *s; 2031 2032 s = migrate_get_current(); 2033 2034 return s->parameters.xbzrle_cache_size; 2035 } 2036 2037 static int64_t migrate_max_postcopy_bandwidth(void) 2038 { 2039 MigrationState *s; 2040 2041 s = migrate_get_current(); 2042 2043 return s->parameters.max_postcopy_bandwidth; 2044 } 2045 2046 bool migrate_use_block(void) 2047 { 2048 MigrationState *s; 2049 2050 s = migrate_get_current(); 2051 2052 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK]; 2053 } 2054 2055 bool migrate_use_return_path(void) 2056 { 2057 MigrationState *s; 2058 2059 s = migrate_get_current(); 2060 2061 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH]; 2062 } 2063 2064 bool migrate_use_block_incremental(void) 2065 { 2066 MigrationState *s; 2067 2068 s = migrate_get_current(); 2069 2070 return s->parameters.block_incremental; 2071 } 2072 2073 /* migration thread support */ 2074 /* 2075 * Something bad happened to the RP stream, mark an error 2076 * The caller shall print or trace something to indicate why 2077 */ 2078 static void mark_source_rp_bad(MigrationState *s) 2079 { 2080 s->rp_state.error = true; 2081 } 2082 2083 static struct rp_cmd_args { 2084 ssize_t len; /* -1 = variable */ 2085 const char *name; 2086 } rp_cmd_args[] = { 2087 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, 2088 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, 2089 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, 2090 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, 2091 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, 2092 [MIG_RP_MSG_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" }, 2093 [MIG_RP_MSG_RESUME_ACK] = { .len = 4, .name = "RESUME_ACK" }, 2094 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, 2095 }; 2096 2097 /* 2098 * Process a request for pages received on the return path, 2099 * We're allowed to send more than requested (e.g. to round to our page size) 2100 * and we don't need to send pages that have already been sent. 2101 */ 2102 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, 2103 ram_addr_t start, size_t len) 2104 { 2105 long our_host_ps = getpagesize(); 2106 2107 trace_migrate_handle_rp_req_pages(rbname, start, len); 2108 2109 /* 2110 * Since we currently insist on matching page sizes, just sanity check 2111 * we're being asked for whole host pages. 2112 */ 2113 if (start & (our_host_ps-1) || 2114 (len & (our_host_ps-1))) { 2115 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT 2116 " len: %zd", __func__, start, len); 2117 mark_source_rp_bad(ms); 2118 return; 2119 } 2120 2121 if (ram_save_queue_pages(rbname, start, len)) { 2122 mark_source_rp_bad(ms); 2123 } 2124 } 2125 2126 /* Return true to retry, false to quit */ 2127 static bool postcopy_pause_return_path_thread(MigrationState *s) 2128 { 2129 trace_postcopy_pause_return_path(); 2130 2131 qemu_sem_wait(&s->postcopy_pause_rp_sem); 2132 2133 trace_postcopy_pause_return_path_continued(); 2134 2135 return true; 2136 } 2137 2138 static int migrate_handle_rp_recv_bitmap(MigrationState *s, char *block_name) 2139 { 2140 RAMBlock *block = qemu_ram_block_by_name(block_name); 2141 2142 if (!block) { 2143 error_report("%s: invalid block name '%s'", __func__, block_name); 2144 return -EINVAL; 2145 } 2146 2147 /* Fetch the received bitmap and refresh the dirty bitmap */ 2148 return ram_dirty_bitmap_reload(s, block); 2149 } 2150 2151 static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value) 2152 { 2153 trace_source_return_path_thread_resume_ack(value); 2154 2155 if (value != MIGRATION_RESUME_ACK_VALUE) { 2156 error_report("%s: illegal resume_ack value %"PRIu32, 2157 __func__, value); 2158 return -1; 2159 } 2160 2161 /* Now both sides are active. */ 2162 migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER, 2163 MIGRATION_STATUS_POSTCOPY_ACTIVE); 2164 2165 /* Notify send thread that time to continue send pages */ 2166 qemu_sem_post(&s->rp_state.rp_sem); 2167 2168 return 0; 2169 } 2170 2171 /* 2172 * Handles messages sent on the return path towards the source VM 2173 * 2174 */ 2175 static void *source_return_path_thread(void *opaque) 2176 { 2177 MigrationState *ms = opaque; 2178 QEMUFile *rp = ms->rp_state.from_dst_file; 2179 uint16_t header_len, header_type; 2180 uint8_t buf[512]; 2181 uint32_t tmp32, sibling_error; 2182 ram_addr_t start = 0; /* =0 to silence warning */ 2183 size_t len = 0, expected_len; 2184 int res; 2185 2186 trace_source_return_path_thread_entry(); 2187 rcu_register_thread(); 2188 2189 retry: 2190 while (!ms->rp_state.error && !qemu_file_get_error(rp) && 2191 migration_is_setup_or_active(ms->state)) { 2192 trace_source_return_path_thread_loop_top(); 2193 header_type = qemu_get_be16(rp); 2194 header_len = qemu_get_be16(rp); 2195 2196 if (qemu_file_get_error(rp)) { 2197 mark_source_rp_bad(ms); 2198 goto out; 2199 } 2200 2201 if (header_type >= MIG_RP_MSG_MAX || 2202 header_type == MIG_RP_MSG_INVALID) { 2203 error_report("RP: Received invalid message 0x%04x length 0x%04x", 2204 header_type, header_len); 2205 mark_source_rp_bad(ms); 2206 goto out; 2207 } 2208 2209 if ((rp_cmd_args[header_type].len != -1 && 2210 header_len != rp_cmd_args[header_type].len) || 2211 header_len > sizeof(buf)) { 2212 error_report("RP: Received '%s' message (0x%04x) with" 2213 "incorrect length %d expecting %zu", 2214 rp_cmd_args[header_type].name, header_type, header_len, 2215 (size_t)rp_cmd_args[header_type].len); 2216 mark_source_rp_bad(ms); 2217 goto out; 2218 } 2219 2220 /* We know we've got a valid header by this point */ 2221 res = qemu_get_buffer(rp, buf, header_len); 2222 if (res != header_len) { 2223 error_report("RP: Failed reading data for message 0x%04x" 2224 " read %d expected %d", 2225 header_type, res, header_len); 2226 mark_source_rp_bad(ms); 2227 goto out; 2228 } 2229 2230 /* OK, we have the message and the data */ 2231 switch (header_type) { 2232 case MIG_RP_MSG_SHUT: 2233 sibling_error = ldl_be_p(buf); 2234 trace_source_return_path_thread_shut(sibling_error); 2235 if (sibling_error) { 2236 error_report("RP: Sibling indicated error %d", sibling_error); 2237 mark_source_rp_bad(ms); 2238 } 2239 /* 2240 * We'll let the main thread deal with closing the RP 2241 * we could do a shutdown(2) on it, but we're the only user 2242 * anyway, so there's nothing gained. 2243 */ 2244 goto out; 2245 2246 case MIG_RP_MSG_PONG: 2247 tmp32 = ldl_be_p(buf); 2248 trace_source_return_path_thread_pong(tmp32); 2249 break; 2250 2251 case MIG_RP_MSG_REQ_PAGES: 2252 start = ldq_be_p(buf); 2253 len = ldl_be_p(buf + 8); 2254 migrate_handle_rp_req_pages(ms, NULL, start, len); 2255 break; 2256 2257 case MIG_RP_MSG_REQ_PAGES_ID: 2258 expected_len = 12 + 1; /* header + termination */ 2259 2260 if (header_len >= expected_len) { 2261 start = ldq_be_p(buf); 2262 len = ldl_be_p(buf + 8); 2263 /* Now we expect an idstr */ 2264 tmp32 = buf[12]; /* Length of the following idstr */ 2265 buf[13 + tmp32] = '\0'; 2266 expected_len += tmp32; 2267 } 2268 if (header_len != expected_len) { 2269 error_report("RP: Req_Page_id with length %d expecting %zd", 2270 header_len, expected_len); 2271 mark_source_rp_bad(ms); 2272 goto out; 2273 } 2274 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); 2275 break; 2276 2277 case MIG_RP_MSG_RECV_BITMAP: 2278 if (header_len < 1) { 2279 error_report("%s: missing block name", __func__); 2280 mark_source_rp_bad(ms); 2281 goto out; 2282 } 2283 /* Format: len (1B) + idstr (<255B). This ends the idstr. */ 2284 buf[buf[0] + 1] = '\0'; 2285 if (migrate_handle_rp_recv_bitmap(ms, (char *)(buf + 1))) { 2286 mark_source_rp_bad(ms); 2287 goto out; 2288 } 2289 break; 2290 2291 case MIG_RP_MSG_RESUME_ACK: 2292 tmp32 = ldl_be_p(buf); 2293 if (migrate_handle_rp_resume_ack(ms, tmp32)) { 2294 mark_source_rp_bad(ms); 2295 goto out; 2296 } 2297 break; 2298 2299 default: 2300 break; 2301 } 2302 } 2303 2304 out: 2305 res = qemu_file_get_error(rp); 2306 if (res) { 2307 if (res == -EIO) { 2308 /* 2309 * Maybe there is something we can do: it looks like a 2310 * network down issue, and we pause for a recovery. 2311 */ 2312 if (postcopy_pause_return_path_thread(ms)) { 2313 /* Reload rp, reset the rest */ 2314 if (rp != ms->rp_state.from_dst_file) { 2315 qemu_fclose(rp); 2316 rp = ms->rp_state.from_dst_file; 2317 } 2318 ms->rp_state.error = false; 2319 goto retry; 2320 } 2321 } 2322 2323 trace_source_return_path_thread_bad_end(); 2324 mark_source_rp_bad(ms); 2325 } 2326 2327 trace_source_return_path_thread_end(); 2328 ms->rp_state.from_dst_file = NULL; 2329 qemu_fclose(rp); 2330 rcu_unregister_thread(); 2331 return NULL; 2332 } 2333 2334 static int open_return_path_on_source(MigrationState *ms, 2335 bool create_thread) 2336 { 2337 2338 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); 2339 if (!ms->rp_state.from_dst_file) { 2340 return -1; 2341 } 2342 2343 trace_open_return_path_on_source(); 2344 2345 if (!create_thread) { 2346 /* We're done */ 2347 return 0; 2348 } 2349 2350 qemu_thread_create(&ms->rp_state.rp_thread, "return path", 2351 source_return_path_thread, ms, QEMU_THREAD_JOINABLE); 2352 2353 trace_open_return_path_on_source_continue(); 2354 2355 return 0; 2356 } 2357 2358 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */ 2359 static int await_return_path_close_on_source(MigrationState *ms) 2360 { 2361 /* 2362 * If this is a normal exit then the destination will send a SHUT and the 2363 * rp_thread will exit, however if there's an error we need to cause 2364 * it to exit. 2365 */ 2366 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) { 2367 /* 2368 * shutdown(2), if we have it, will cause it to unblock if it's stuck 2369 * waiting for the destination. 2370 */ 2371 qemu_file_shutdown(ms->rp_state.from_dst_file); 2372 mark_source_rp_bad(ms); 2373 } 2374 trace_await_return_path_close_on_source_joining(); 2375 qemu_thread_join(&ms->rp_state.rp_thread); 2376 trace_await_return_path_close_on_source_close(); 2377 return ms->rp_state.error; 2378 } 2379 2380 /* 2381 * Switch from normal iteration to postcopy 2382 * Returns non-0 on error 2383 */ 2384 static int postcopy_start(MigrationState *ms) 2385 { 2386 int ret; 2387 QIOChannelBuffer *bioc; 2388 QEMUFile *fb; 2389 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2390 int64_t bandwidth = migrate_max_postcopy_bandwidth(); 2391 bool restart_block = false; 2392 int cur_state = MIGRATION_STATUS_ACTIVE; 2393 if (!migrate_pause_before_switchover()) { 2394 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE, 2395 MIGRATION_STATUS_POSTCOPY_ACTIVE); 2396 } 2397 2398 trace_postcopy_start(); 2399 qemu_mutex_lock_iothread(); 2400 trace_postcopy_start_set_run(); 2401 2402 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 2403 global_state_store(); 2404 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 2405 if (ret < 0) { 2406 goto fail; 2407 } 2408 2409 ret = migration_maybe_pause(ms, &cur_state, 2410 MIGRATION_STATUS_POSTCOPY_ACTIVE); 2411 if (ret < 0) { 2412 goto fail; 2413 } 2414 2415 ret = bdrv_inactivate_all(); 2416 if (ret < 0) { 2417 goto fail; 2418 } 2419 restart_block = true; 2420 2421 /* 2422 * Cause any non-postcopiable, but iterative devices to 2423 * send out their final data. 2424 */ 2425 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false); 2426 2427 /* 2428 * in Finish migrate and with the io-lock held everything should 2429 * be quiet, but we've potentially still got dirty pages and we 2430 * need to tell the destination to throw any pages it's already received 2431 * that are dirty 2432 */ 2433 if (migrate_postcopy_ram()) { 2434 if (ram_postcopy_send_discard_bitmap(ms)) { 2435 error_report("postcopy send discard bitmap failed"); 2436 goto fail; 2437 } 2438 } 2439 2440 /* 2441 * send rest of state - note things that are doing postcopy 2442 * will notice we're in POSTCOPY_ACTIVE and not actually 2443 * wrap their state up here 2444 */ 2445 /* 0 max-postcopy-bandwidth means unlimited */ 2446 if (!bandwidth) { 2447 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); 2448 } else { 2449 qemu_file_set_rate_limit(ms->to_dst_file, bandwidth / XFER_LIMIT_RATIO); 2450 } 2451 if (migrate_postcopy_ram()) { 2452 /* Ping just for debugging, helps line traces up */ 2453 qemu_savevm_send_ping(ms->to_dst_file, 2); 2454 } 2455 2456 /* 2457 * While loading the device state we may trigger page transfer 2458 * requests and the fd must be free to process those, and thus 2459 * the destination must read the whole device state off the fd before 2460 * it starts processing it. Unfortunately the ad-hoc migration format 2461 * doesn't allow the destination to know the size to read without fully 2462 * parsing it through each devices load-state code (especially the open 2463 * coded devices that use get/put). 2464 * So we wrap the device state up in a package with a length at the start; 2465 * to do this we use a qemu_buf to hold the whole of the device state. 2466 */ 2467 bioc = qio_channel_buffer_new(4096); 2468 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer"); 2469 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 2470 object_unref(OBJECT(bioc)); 2471 2472 /* 2473 * Make sure the receiver can get incoming pages before we send the rest 2474 * of the state 2475 */ 2476 qemu_savevm_send_postcopy_listen(fb); 2477 2478 qemu_savevm_state_complete_precopy(fb, false, false); 2479 if (migrate_postcopy_ram()) { 2480 qemu_savevm_send_ping(fb, 3); 2481 } 2482 2483 qemu_savevm_send_postcopy_run(fb); 2484 2485 /* <><> end of stuff going into the package */ 2486 2487 /* Last point of recovery; as soon as we send the package the destination 2488 * can open devices and potentially start running. 2489 * Lets just check again we've not got any errors. 2490 */ 2491 ret = qemu_file_get_error(ms->to_dst_file); 2492 if (ret) { 2493 error_report("postcopy_start: Migration stream errored (pre package)"); 2494 goto fail_closefb; 2495 } 2496 2497 restart_block = false; 2498 2499 /* Now send that blob */ 2500 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) { 2501 goto fail_closefb; 2502 } 2503 qemu_fclose(fb); 2504 2505 /* Send a notify to give a chance for anything that needs to happen 2506 * at the transition to postcopy and after the device state; in particular 2507 * spice needs to trigger a transition now 2508 */ 2509 ms->postcopy_after_devices = true; 2510 notifier_list_notify(&migration_state_notifiers, ms); 2511 2512 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop; 2513 2514 qemu_mutex_unlock_iothread(); 2515 2516 if (migrate_postcopy_ram()) { 2517 /* 2518 * Although this ping is just for debug, it could potentially be 2519 * used for getting a better measurement of downtime at the source. 2520 */ 2521 qemu_savevm_send_ping(ms->to_dst_file, 4); 2522 } 2523 2524 if (migrate_release_ram()) { 2525 ram_postcopy_migrated_memory_release(ms); 2526 } 2527 2528 ret = qemu_file_get_error(ms->to_dst_file); 2529 if (ret) { 2530 error_report("postcopy_start: Migration stream errored"); 2531 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2532 MIGRATION_STATUS_FAILED); 2533 } 2534 2535 return ret; 2536 2537 fail_closefb: 2538 qemu_fclose(fb); 2539 fail: 2540 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2541 MIGRATION_STATUS_FAILED); 2542 if (restart_block) { 2543 /* A failure happened early enough that we know the destination hasn't 2544 * accessed block devices, so we're safe to recover. 2545 */ 2546 Error *local_err = NULL; 2547 2548 bdrv_invalidate_cache_all(&local_err); 2549 if (local_err) { 2550 error_report_err(local_err); 2551 } 2552 } 2553 qemu_mutex_unlock_iothread(); 2554 return -1; 2555 } 2556 2557 /** 2558 * migration_maybe_pause: Pause if required to by 2559 * migrate_pause_before_switchover called with the iothread locked 2560 * Returns: 0 on success 2561 */ 2562 static int migration_maybe_pause(MigrationState *s, 2563 int *current_active_state, 2564 int new_state) 2565 { 2566 if (!migrate_pause_before_switchover()) { 2567 return 0; 2568 } 2569 2570 /* Since leaving this state is not atomic with posting the semaphore 2571 * it's possible that someone could have issued multiple migrate_continue 2572 * and the semaphore is incorrectly positive at this point; 2573 * the docs say it's undefined to reinit a semaphore that's already 2574 * init'd, so use timedwait to eat up any existing posts. 2575 */ 2576 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) { 2577 /* This block intentionally left blank */ 2578 } 2579 2580 qemu_mutex_unlock_iothread(); 2581 migrate_set_state(&s->state, *current_active_state, 2582 MIGRATION_STATUS_PRE_SWITCHOVER); 2583 qemu_sem_wait(&s->pause_sem); 2584 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER, 2585 new_state); 2586 *current_active_state = new_state; 2587 qemu_mutex_lock_iothread(); 2588 2589 return s->state == new_state ? 0 : -EINVAL; 2590 } 2591 2592 /** 2593 * migration_completion: Used by migration_thread when there's not much left. 2594 * The caller 'breaks' the loop when this returns. 2595 * 2596 * @s: Current migration state 2597 */ 2598 static void migration_completion(MigrationState *s) 2599 { 2600 int ret; 2601 int current_active_state = s->state; 2602 2603 if (s->state == MIGRATION_STATUS_ACTIVE) { 2604 qemu_mutex_lock_iothread(); 2605 s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2606 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 2607 s->vm_was_running = runstate_is_running(); 2608 ret = global_state_store(); 2609 2610 if (!ret) { 2611 bool inactivate = !migrate_colo_enabled(); 2612 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); 2613 if (ret >= 0) { 2614 ret = migration_maybe_pause(s, ¤t_active_state, 2615 MIGRATION_STATUS_DEVICE); 2616 } 2617 if (ret >= 0) { 2618 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX); 2619 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false, 2620 inactivate); 2621 } 2622 if (inactivate && ret >= 0) { 2623 s->block_inactive = true; 2624 } 2625 } 2626 qemu_mutex_unlock_iothread(); 2627 2628 if (ret < 0) { 2629 goto fail; 2630 } 2631 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 2632 trace_migration_completion_postcopy_end(); 2633 2634 qemu_savevm_state_complete_postcopy(s->to_dst_file); 2635 trace_migration_completion_postcopy_end_after_complete(); 2636 } 2637 2638 /* 2639 * If rp was opened we must clean up the thread before 2640 * cleaning everything else up (since if there are no failures 2641 * it will wait for the destination to send it's status in 2642 * a SHUT command). 2643 */ 2644 if (s->rp_state.from_dst_file) { 2645 int rp_error; 2646 trace_migration_return_path_end_before(); 2647 rp_error = await_return_path_close_on_source(s); 2648 trace_migration_return_path_end_after(rp_error); 2649 if (rp_error) { 2650 goto fail_invalidate; 2651 } 2652 } 2653 2654 if (qemu_file_get_error(s->to_dst_file)) { 2655 trace_migration_completion_file_err(); 2656 goto fail_invalidate; 2657 } 2658 2659 if (!migrate_colo_enabled()) { 2660 migrate_set_state(&s->state, current_active_state, 2661 MIGRATION_STATUS_COMPLETED); 2662 } 2663 2664 return; 2665 2666 fail_invalidate: 2667 /* If not doing postcopy, vm_start() will be called: let's regain 2668 * control on images. 2669 */ 2670 if (s->state == MIGRATION_STATUS_ACTIVE || 2671 s->state == MIGRATION_STATUS_DEVICE) { 2672 Error *local_err = NULL; 2673 2674 qemu_mutex_lock_iothread(); 2675 bdrv_invalidate_cache_all(&local_err); 2676 if (local_err) { 2677 error_report_err(local_err); 2678 } else { 2679 s->block_inactive = false; 2680 } 2681 qemu_mutex_unlock_iothread(); 2682 } 2683 2684 fail: 2685 migrate_set_state(&s->state, current_active_state, 2686 MIGRATION_STATUS_FAILED); 2687 } 2688 2689 bool migrate_colo_enabled(void) 2690 { 2691 MigrationState *s = migrate_get_current(); 2692 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO]; 2693 } 2694 2695 typedef enum MigThrError { 2696 /* No error detected */ 2697 MIG_THR_ERR_NONE = 0, 2698 /* Detected error, but resumed successfully */ 2699 MIG_THR_ERR_RECOVERED = 1, 2700 /* Detected fatal error, need to exit */ 2701 MIG_THR_ERR_FATAL = 2, 2702 } MigThrError; 2703 2704 static int postcopy_resume_handshake(MigrationState *s) 2705 { 2706 qemu_savevm_send_postcopy_resume(s->to_dst_file); 2707 2708 while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) { 2709 qemu_sem_wait(&s->rp_state.rp_sem); 2710 } 2711 2712 if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 2713 return 0; 2714 } 2715 2716 return -1; 2717 } 2718 2719 /* Return zero if success, or <0 for error */ 2720 static int postcopy_do_resume(MigrationState *s) 2721 { 2722 int ret; 2723 2724 /* 2725 * Call all the resume_prepare() hooks, so that modules can be 2726 * ready for the migration resume. 2727 */ 2728 ret = qemu_savevm_state_resume_prepare(s); 2729 if (ret) { 2730 error_report("%s: resume_prepare() failure detected: %d", 2731 __func__, ret); 2732 return ret; 2733 } 2734 2735 /* 2736 * Last handshake with destination on the resume (destination will 2737 * switch to postcopy-active afterwards) 2738 */ 2739 ret = postcopy_resume_handshake(s); 2740 if (ret) { 2741 error_report("%s: handshake failed: %d", __func__, ret); 2742 return ret; 2743 } 2744 2745 return 0; 2746 } 2747 2748 /* 2749 * We don't return until we are in a safe state to continue current 2750 * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or 2751 * MIG_THR_ERR_FATAL if unrecovery failure happened. 2752 */ 2753 static MigThrError postcopy_pause(MigrationState *s) 2754 { 2755 assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 2756 2757 while (true) { 2758 QEMUFile *file; 2759 2760 migrate_set_state(&s->state, s->state, 2761 MIGRATION_STATUS_POSTCOPY_PAUSED); 2762 2763 /* Current channel is possibly broken. Release it. */ 2764 assert(s->to_dst_file); 2765 qemu_mutex_lock(&s->qemu_file_lock); 2766 file = s->to_dst_file; 2767 s->to_dst_file = NULL; 2768 qemu_mutex_unlock(&s->qemu_file_lock); 2769 2770 qemu_file_shutdown(file); 2771 qemu_fclose(file); 2772 2773 error_report("Detected IO failure for postcopy. " 2774 "Migration paused."); 2775 2776 /* 2777 * We wait until things fixed up. Then someone will setup the 2778 * status back for us. 2779 */ 2780 while (s->state == MIGRATION_STATUS_POSTCOPY_PAUSED) { 2781 qemu_sem_wait(&s->postcopy_pause_sem); 2782 } 2783 2784 if (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) { 2785 /* Woken up by a recover procedure. Give it a shot */ 2786 2787 /* 2788 * Firstly, let's wake up the return path now, with a new 2789 * return path channel. 2790 */ 2791 qemu_sem_post(&s->postcopy_pause_rp_sem); 2792 2793 /* Do the resume logic */ 2794 if (postcopy_do_resume(s) == 0) { 2795 /* Let's continue! */ 2796 trace_postcopy_pause_continued(); 2797 return MIG_THR_ERR_RECOVERED; 2798 } else { 2799 /* 2800 * Something wrong happened during the recovery, let's 2801 * pause again. Pause is always better than throwing 2802 * data away. 2803 */ 2804 continue; 2805 } 2806 } else { 2807 /* This is not right... Time to quit. */ 2808 return MIG_THR_ERR_FATAL; 2809 } 2810 } 2811 } 2812 2813 static MigThrError migration_detect_error(MigrationState *s) 2814 { 2815 int ret; 2816 2817 /* Try to detect any file errors */ 2818 ret = qemu_file_get_error(s->to_dst_file); 2819 2820 if (!ret) { 2821 /* Everything is fine */ 2822 return MIG_THR_ERR_NONE; 2823 } 2824 2825 if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) { 2826 /* 2827 * For postcopy, we allow the network to be down for a 2828 * while. After that, it can be continued by a 2829 * recovery phase. 2830 */ 2831 return postcopy_pause(s); 2832 } else { 2833 /* 2834 * For precopy (or postcopy with error outside IO), we fail 2835 * with no time. 2836 */ 2837 migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED); 2838 trace_migration_thread_file_err(); 2839 2840 /* Time to stop the migration, now. */ 2841 return MIG_THR_ERR_FATAL; 2842 } 2843 } 2844 2845 /* How many bytes have we transferred since the beggining of the migration */ 2846 static uint64_t migration_total_bytes(MigrationState *s) 2847 { 2848 return qemu_ftell(s->to_dst_file) + ram_counters.multifd_bytes; 2849 } 2850 2851 static void migration_calculate_complete(MigrationState *s) 2852 { 2853 uint64_t bytes = migration_total_bytes(s); 2854 int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 2855 int64_t transfer_time; 2856 2857 s->total_time = end_time - s->start_time; 2858 if (!s->downtime) { 2859 /* 2860 * It's still not set, so we are precopy migration. For 2861 * postcopy, downtime is calculated during postcopy_start(). 2862 */ 2863 s->downtime = end_time - s->downtime_start; 2864 } 2865 2866 transfer_time = s->total_time - s->setup_time; 2867 if (transfer_time) { 2868 s->mbps = ((double) bytes * 8.0) / transfer_time / 1000; 2869 } 2870 } 2871 2872 static void migration_update_counters(MigrationState *s, 2873 int64_t current_time) 2874 { 2875 uint64_t transferred, time_spent; 2876 uint64_t current_bytes; /* bytes transferred since the beginning */ 2877 double bandwidth; 2878 2879 if (current_time < s->iteration_start_time + BUFFER_DELAY) { 2880 return; 2881 } 2882 2883 current_bytes = migration_total_bytes(s); 2884 transferred = current_bytes - s->iteration_initial_bytes; 2885 time_spent = current_time - s->iteration_start_time; 2886 bandwidth = (double)transferred / time_spent; 2887 s->threshold_size = bandwidth * s->parameters.downtime_limit; 2888 2889 s->mbps = (((double) transferred * 8.0) / 2890 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; 2891 2892 /* 2893 * if we haven't sent anything, we don't want to 2894 * recalculate. 10000 is a small enough number for our purposes 2895 */ 2896 if (ram_counters.dirty_pages_rate && transferred > 10000) { 2897 s->expected_downtime = ram_counters.remaining / bandwidth; 2898 } 2899 2900 qemu_file_reset_rate_limit(s->to_dst_file); 2901 2902 s->iteration_start_time = current_time; 2903 s->iteration_initial_bytes = current_bytes; 2904 2905 trace_migrate_transferred(transferred, time_spent, 2906 bandwidth, s->threshold_size); 2907 } 2908 2909 /* Migration thread iteration status */ 2910 typedef enum { 2911 MIG_ITERATE_RESUME, /* Resume current iteration */ 2912 MIG_ITERATE_SKIP, /* Skip current iteration */ 2913 MIG_ITERATE_BREAK, /* Break the loop */ 2914 } MigIterateState; 2915 2916 /* 2917 * Return true if continue to the next iteration directly, false 2918 * otherwise. 2919 */ 2920 static MigIterateState migration_iteration_run(MigrationState *s) 2921 { 2922 uint64_t pending_size, pend_pre, pend_compat, pend_post; 2923 bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE; 2924 2925 qemu_savevm_state_pending(s->to_dst_file, s->threshold_size, &pend_pre, 2926 &pend_compat, &pend_post); 2927 pending_size = pend_pre + pend_compat + pend_post; 2928 2929 trace_migrate_pending(pending_size, s->threshold_size, 2930 pend_pre, pend_compat, pend_post); 2931 2932 if (pending_size && pending_size >= s->threshold_size) { 2933 /* Still a significant amount to transfer */ 2934 if (migrate_postcopy() && !in_postcopy && 2935 pend_pre <= s->threshold_size && 2936 atomic_read(&s->start_postcopy)) { 2937 if (postcopy_start(s)) { 2938 error_report("%s: postcopy failed to start", __func__); 2939 } 2940 return MIG_ITERATE_SKIP; 2941 } 2942 /* Just another iteration step */ 2943 qemu_savevm_state_iterate(s->to_dst_file, 2944 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); 2945 } else { 2946 trace_migration_thread_low_pending(pending_size); 2947 migration_completion(s); 2948 return MIG_ITERATE_BREAK; 2949 } 2950 2951 return MIG_ITERATE_RESUME; 2952 } 2953 2954 static void migration_iteration_finish(MigrationState *s) 2955 { 2956 /* If we enabled cpu throttling for auto-converge, turn it off. */ 2957 cpu_throttle_stop(); 2958 2959 qemu_mutex_lock_iothread(); 2960 switch (s->state) { 2961 case MIGRATION_STATUS_COMPLETED: 2962 migration_calculate_complete(s); 2963 runstate_set(RUN_STATE_POSTMIGRATE); 2964 break; 2965 2966 case MIGRATION_STATUS_ACTIVE: 2967 /* 2968 * We should really assert here, but since it's during 2969 * migration, let's try to reduce the usage of assertions. 2970 */ 2971 if (!migrate_colo_enabled()) { 2972 error_report("%s: critical error: calling COLO code without " 2973 "COLO enabled", __func__); 2974 } 2975 migrate_start_colo_process(s); 2976 /* 2977 * Fixme: we will run VM in COLO no matter its old running state. 2978 * After exited COLO, we will keep running. 2979 */ 2980 s->vm_was_running = true; 2981 /* Fallthrough */ 2982 case MIGRATION_STATUS_FAILED: 2983 case MIGRATION_STATUS_CANCELLED: 2984 case MIGRATION_STATUS_CANCELLING: 2985 if (s->vm_was_running) { 2986 vm_start(); 2987 } else { 2988 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) { 2989 runstate_set(RUN_STATE_POSTMIGRATE); 2990 } 2991 } 2992 break; 2993 2994 default: 2995 /* Should not reach here, but if so, forgive the VM. */ 2996 error_report("%s: Unknown ending state %d", __func__, s->state); 2997 break; 2998 } 2999 qemu_bh_schedule(s->cleanup_bh); 3000 qemu_mutex_unlock_iothread(); 3001 } 3002 3003 void migration_make_urgent_request(void) 3004 { 3005 qemu_sem_post(&migrate_get_current()->rate_limit_sem); 3006 } 3007 3008 void migration_consume_urgent_request(void) 3009 { 3010 qemu_sem_wait(&migrate_get_current()->rate_limit_sem); 3011 } 3012 3013 /* 3014 * Master migration thread on the source VM. 3015 * It drives the migration and pumps the data down the outgoing channel. 3016 */ 3017 static void *migration_thread(void *opaque) 3018 { 3019 MigrationState *s = opaque; 3020 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); 3021 MigThrError thr_error; 3022 bool urgent = false; 3023 3024 rcu_register_thread(); 3025 3026 s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 3027 3028 qemu_savevm_state_header(s->to_dst_file); 3029 3030 /* 3031 * If we opened the return path, we need to make sure dst has it 3032 * opened as well. 3033 */ 3034 if (s->rp_state.from_dst_file) { 3035 /* Now tell the dest that it should open its end so it can reply */ 3036 qemu_savevm_send_open_return_path(s->to_dst_file); 3037 3038 /* And do a ping that will make stuff easier to debug */ 3039 qemu_savevm_send_ping(s->to_dst_file, 1); 3040 } 3041 3042 if (migrate_postcopy()) { 3043 /* 3044 * Tell the destination that we *might* want to do postcopy later; 3045 * if the other end can't do postcopy it should fail now, nice and 3046 * early. 3047 */ 3048 qemu_savevm_send_postcopy_advise(s->to_dst_file); 3049 } 3050 3051 if (migrate_colo_enabled()) { 3052 /* Notify migration destination that we enable COLO */ 3053 qemu_savevm_send_colo_enable(s->to_dst_file); 3054 } 3055 3056 qemu_savevm_state_setup(s->to_dst_file); 3057 3058 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; 3059 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 3060 MIGRATION_STATUS_ACTIVE); 3061 3062 trace_migration_thread_setup_complete(); 3063 3064 while (s->state == MIGRATION_STATUS_ACTIVE || 3065 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { 3066 int64_t current_time; 3067 3068 if (urgent || !qemu_file_rate_limit(s->to_dst_file)) { 3069 MigIterateState iter_state = migration_iteration_run(s); 3070 if (iter_state == MIG_ITERATE_SKIP) { 3071 continue; 3072 } else if (iter_state == MIG_ITERATE_BREAK) { 3073 break; 3074 } 3075 } 3076 3077 /* 3078 * Try to detect any kind of failures, and see whether we 3079 * should stop the migration now. 3080 */ 3081 thr_error = migration_detect_error(s); 3082 if (thr_error == MIG_THR_ERR_FATAL) { 3083 /* Stop migration */ 3084 break; 3085 } else if (thr_error == MIG_THR_ERR_RECOVERED) { 3086 /* 3087 * Just recovered from a e.g. network failure, reset all 3088 * the local variables. This is important to avoid 3089 * breaking transferred_bytes and bandwidth calculation 3090 */ 3091 s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 3092 s->iteration_initial_bytes = 0; 3093 } 3094 3095 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); 3096 3097 migration_update_counters(s, current_time); 3098 3099 urgent = false; 3100 if (qemu_file_rate_limit(s->to_dst_file)) { 3101 /* Wait for a delay to do rate limiting OR 3102 * something urgent to post the semaphore. 3103 */ 3104 int ms = s->iteration_start_time + BUFFER_DELAY - current_time; 3105 trace_migration_thread_ratelimit_pre(ms); 3106 if (qemu_sem_timedwait(&s->rate_limit_sem, ms) == 0) { 3107 /* We were worken by one or more urgent things but 3108 * the timedwait will have consumed one of them. 3109 * The service routine for the urgent wake will dec 3110 * the semaphore itself for each item it consumes, 3111 * so add this one we just eat back. 3112 */ 3113 qemu_sem_post(&s->rate_limit_sem); 3114 urgent = true; 3115 } 3116 trace_migration_thread_ratelimit_post(urgent); 3117 } 3118 } 3119 3120 trace_migration_thread_after_loop(); 3121 migration_iteration_finish(s); 3122 rcu_unregister_thread(); 3123 return NULL; 3124 } 3125 3126 void migrate_fd_connect(MigrationState *s, Error *error_in) 3127 { 3128 int64_t rate_limit; 3129 bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED; 3130 3131 s->expected_downtime = s->parameters.downtime_limit; 3132 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); 3133 if (error_in) { 3134 migrate_fd_error(s, error_in); 3135 migrate_fd_cleanup(s); 3136 return; 3137 } 3138 3139 if (resume) { 3140 /* This is a resumed migration */ 3141 rate_limit = INT64_MAX; 3142 } else { 3143 /* This is a fresh new migration */ 3144 rate_limit = s->parameters.max_bandwidth / XFER_LIMIT_RATIO; 3145 3146 /* Notify before starting migration thread */ 3147 notifier_list_notify(&migration_state_notifiers, s); 3148 } 3149 3150 qemu_file_set_rate_limit(s->to_dst_file, rate_limit); 3151 qemu_file_set_blocking(s->to_dst_file, true); 3152 3153 /* 3154 * Open the return path. For postcopy, it is used exclusively. For 3155 * precopy, only if user specified "return-path" capability would 3156 * QEMU uses the return path. 3157 */ 3158 if (migrate_postcopy_ram() || migrate_use_return_path()) { 3159 if (open_return_path_on_source(s, !resume)) { 3160 error_report("Unable to open return-path for postcopy"); 3161 migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED); 3162 migrate_fd_cleanup(s); 3163 return; 3164 } 3165 } 3166 3167 if (resume) { 3168 /* Wakeup the main migration thread to do the recovery */ 3169 migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_PAUSED, 3170 MIGRATION_STATUS_POSTCOPY_RECOVER); 3171 qemu_sem_post(&s->postcopy_pause_sem); 3172 return; 3173 } 3174 3175 if (multifd_save_setup() != 0) { 3176 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, 3177 MIGRATION_STATUS_FAILED); 3178 migrate_fd_cleanup(s); 3179 return; 3180 } 3181 qemu_thread_create(&s->thread, "live_migration", migration_thread, s, 3182 QEMU_THREAD_JOINABLE); 3183 s->migration_thread_running = true; 3184 } 3185 3186 void migration_global_dump(Monitor *mon) 3187 { 3188 MigrationState *ms = migrate_get_current(); 3189 3190 monitor_printf(mon, "globals:\n"); 3191 monitor_printf(mon, "store-global-state: %s\n", 3192 ms->store_global_state ? "on" : "off"); 3193 monitor_printf(mon, "only-migratable: %s\n", 3194 ms->only_migratable ? "on" : "off"); 3195 monitor_printf(mon, "send-configuration: %s\n", 3196 ms->send_configuration ? "on" : "off"); 3197 monitor_printf(mon, "send-section-footer: %s\n", 3198 ms->send_section_footer ? "on" : "off"); 3199 monitor_printf(mon, "decompress-error-check: %s\n", 3200 ms->decompress_error_check ? "on" : "off"); 3201 } 3202 3203 #define DEFINE_PROP_MIG_CAP(name, x) \ 3204 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false) 3205 3206 static Property migration_properties[] = { 3207 DEFINE_PROP_BOOL("store-global-state", MigrationState, 3208 store_global_state, true), 3209 DEFINE_PROP_BOOL("only-migratable", MigrationState, only_migratable, false), 3210 DEFINE_PROP_BOOL("send-configuration", MigrationState, 3211 send_configuration, true), 3212 DEFINE_PROP_BOOL("send-section-footer", MigrationState, 3213 send_section_footer, true), 3214 DEFINE_PROP_BOOL("decompress-error-check", MigrationState, 3215 decompress_error_check, true), 3216 3217 /* Migration parameters */ 3218 DEFINE_PROP_UINT8("x-compress-level", MigrationState, 3219 parameters.compress_level, 3220 DEFAULT_MIGRATE_COMPRESS_LEVEL), 3221 DEFINE_PROP_UINT8("x-compress-threads", MigrationState, 3222 parameters.compress_threads, 3223 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT), 3224 DEFINE_PROP_BOOL("x-compress-wait-thread", MigrationState, 3225 parameters.compress_wait_thread, true), 3226 DEFINE_PROP_UINT8("x-decompress-threads", MigrationState, 3227 parameters.decompress_threads, 3228 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT), 3229 DEFINE_PROP_UINT8("x-cpu-throttle-initial", MigrationState, 3230 parameters.cpu_throttle_initial, 3231 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL), 3232 DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState, 3233 parameters.cpu_throttle_increment, 3234 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT), 3235 DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState, 3236 parameters.max_bandwidth, MAX_THROTTLE), 3237 DEFINE_PROP_UINT64("x-downtime-limit", MigrationState, 3238 parameters.downtime_limit, 3239 DEFAULT_MIGRATE_SET_DOWNTIME), 3240 DEFINE_PROP_UINT32("x-checkpoint-delay", MigrationState, 3241 parameters.x_checkpoint_delay, 3242 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY), 3243 DEFINE_PROP_UINT8("x-multifd-channels", MigrationState, 3244 parameters.x_multifd_channels, 3245 DEFAULT_MIGRATE_MULTIFD_CHANNELS), 3246 DEFINE_PROP_UINT32("x-multifd-page-count", MigrationState, 3247 parameters.x_multifd_page_count, 3248 DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT), 3249 DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState, 3250 parameters.xbzrle_cache_size, 3251 DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE), 3252 DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState, 3253 parameters.max_postcopy_bandwidth, 3254 DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH), 3255 DEFINE_PROP_UINT8("max-cpu-throttle", MigrationState, 3256 parameters.max_cpu_throttle, 3257 DEFAULT_MIGRATE_MAX_CPU_THROTTLE), 3258 3259 /* Migration capabilities */ 3260 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE), 3261 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL), 3262 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE), 3263 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS), 3264 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS), 3265 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS), 3266 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM), 3267 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO), 3268 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM), 3269 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK), 3270 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH), 3271 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_X_MULTIFD), 3272 3273 DEFINE_PROP_END_OF_LIST(), 3274 }; 3275 3276 static void migration_class_init(ObjectClass *klass, void *data) 3277 { 3278 DeviceClass *dc = DEVICE_CLASS(klass); 3279 3280 dc->user_creatable = false; 3281 dc->props = migration_properties; 3282 } 3283 3284 static void migration_instance_finalize(Object *obj) 3285 { 3286 MigrationState *ms = MIGRATION_OBJ(obj); 3287 MigrationParameters *params = &ms->parameters; 3288 3289 qemu_mutex_destroy(&ms->error_mutex); 3290 qemu_mutex_destroy(&ms->qemu_file_lock); 3291 g_free(params->tls_hostname); 3292 g_free(params->tls_creds); 3293 qemu_sem_destroy(&ms->rate_limit_sem); 3294 qemu_sem_destroy(&ms->pause_sem); 3295 qemu_sem_destroy(&ms->postcopy_pause_sem); 3296 qemu_sem_destroy(&ms->postcopy_pause_rp_sem); 3297 qemu_sem_destroy(&ms->rp_state.rp_sem); 3298 error_free(ms->error); 3299 } 3300 3301 static void migration_instance_init(Object *obj) 3302 { 3303 MigrationState *ms = MIGRATION_OBJ(obj); 3304 MigrationParameters *params = &ms->parameters; 3305 3306 ms->state = MIGRATION_STATUS_NONE; 3307 ms->mbps = -1; 3308 qemu_sem_init(&ms->pause_sem, 0); 3309 qemu_mutex_init(&ms->error_mutex); 3310 3311 params->tls_hostname = g_strdup(""); 3312 params->tls_creds = g_strdup(""); 3313 3314 /* Set has_* up only for parameter checks */ 3315 params->has_compress_level = true; 3316 params->has_compress_threads = true; 3317 params->has_decompress_threads = true; 3318 params->has_cpu_throttle_initial = true; 3319 params->has_cpu_throttle_increment = true; 3320 params->has_max_bandwidth = true; 3321 params->has_downtime_limit = true; 3322 params->has_x_checkpoint_delay = true; 3323 params->has_block_incremental = true; 3324 params->has_x_multifd_channels = true; 3325 params->has_x_multifd_page_count = true; 3326 params->has_xbzrle_cache_size = true; 3327 params->has_max_postcopy_bandwidth = true; 3328 params->has_max_cpu_throttle = true; 3329 3330 qemu_sem_init(&ms->postcopy_pause_sem, 0); 3331 qemu_sem_init(&ms->postcopy_pause_rp_sem, 0); 3332 qemu_sem_init(&ms->rp_state.rp_sem, 0); 3333 qemu_sem_init(&ms->rate_limit_sem, 0); 3334 qemu_mutex_init(&ms->qemu_file_lock); 3335 } 3336 3337 /* 3338 * Return true if check pass, false otherwise. Error will be put 3339 * inside errp if provided. 3340 */ 3341 static bool migration_object_check(MigrationState *ms, Error **errp) 3342 { 3343 MigrationCapabilityStatusList *head = NULL; 3344 /* Assuming all off */ 3345 bool cap_list[MIGRATION_CAPABILITY__MAX] = { 0 }, ret; 3346 int i; 3347 3348 if (!migrate_params_check(&ms->parameters, errp)) { 3349 return false; 3350 } 3351 3352 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 3353 if (ms->enabled_capabilities[i]) { 3354 head = migrate_cap_add(head, i, true); 3355 } 3356 } 3357 3358 ret = migrate_caps_check(cap_list, head, errp); 3359 3360 /* It works with head == NULL */ 3361 qapi_free_MigrationCapabilityStatusList(head); 3362 3363 return ret; 3364 } 3365 3366 static const TypeInfo migration_type = { 3367 .name = TYPE_MIGRATION, 3368 /* 3369 * NOTE: TYPE_MIGRATION is not really a device, as the object is 3370 * not created using qdev_create(), it is not attached to the qdev 3371 * device tree, and it is never realized. 3372 * 3373 * TODO: Make this TYPE_OBJECT once QOM provides something like 3374 * TYPE_DEVICE's "-global" properties. 3375 */ 3376 .parent = TYPE_DEVICE, 3377 .class_init = migration_class_init, 3378 .class_size = sizeof(MigrationClass), 3379 .instance_size = sizeof(MigrationState), 3380 .instance_init = migration_instance_init, 3381 .instance_finalize = migration_instance_finalize, 3382 }; 3383 3384 static void register_migration_types(void) 3385 { 3386 type_register_static(&migration_type); 3387 } 3388 3389 type_init(register_migration_types); 3390