1 /* 2 * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO) 3 * (a.k.a. Fault Tolerance or Continuous Replication) 4 * 5 * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. 6 * Copyright (c) 2016 FUJITSU LIMITED 7 * Copyright (c) 2016 Intel Corporation 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or 10 * later. See the COPYING file in the top-level directory. 11 */ 12 13 #include "qemu/osdep.h" 14 #include "sysemu/sysemu.h" 15 #include "qapi/error.h" 16 #include "qapi/qapi-commands-migration.h" 17 #include "migration.h" 18 #include "qemu-file.h" 19 #include "savevm.h" 20 #include "migration/colo.h" 21 #include "block.h" 22 #include "io/channel-buffer.h" 23 #include "trace.h" 24 #include "qemu/error-report.h" 25 #include "qemu/main-loop.h" 26 #include "qemu/rcu.h" 27 #include "migration/failover.h" 28 #include "migration/ram.h" 29 #include "block/replication.h" 30 #include "net/colo-compare.h" 31 #include "net/colo.h" 32 #include "block/block.h" 33 #include "qapi/qapi-events-migration.h" 34 #include "sysemu/cpus.h" 35 #include "sysemu/runstate.h" 36 #include "net/filter.h" 37 #include "options.h" 38 39 static bool vmstate_loading; 40 static Notifier packets_compare_notifier; 41 42 /* User need to know colo mode after COLO failover */ 43 static COLOMode last_colo_mode; 44 45 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024) 46 47 bool migration_in_colo_state(void) 48 { 49 MigrationState *s = migrate_get_current(); 50 51 return (s->state == MIGRATION_STATUS_COLO); 52 } 53 54 bool migration_incoming_in_colo_state(void) 55 { 56 MigrationIncomingState *mis = migration_incoming_get_current(); 57 58 return mis && (mis->state == MIGRATION_STATUS_COLO); 59 } 60 61 static bool colo_runstate_is_stopped(void) 62 { 63 return runstate_check(RUN_STATE_COLO) || !runstate_is_running(); 64 } 65 66 static void colo_checkpoint_notify(void *opaque) 67 { 68 MigrationState *s = opaque; 69 int64_t next_notify_time; 70 71 qemu_event_set(&s->colo_checkpoint_event); 72 s->colo_checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST); 73 next_notify_time = s->colo_checkpoint_time + migrate_checkpoint_delay(); 74 timer_mod(s->colo_delay_timer, next_notify_time); 75 } 76 77 void colo_checkpoint_delay_set(void) 78 { 79 if (migration_in_colo_state()) { 80 colo_checkpoint_notify(migrate_get_current()); 81 } 82 } 83 84 static void secondary_vm_do_failover(void) 85 { 86 /* COLO needs enable block-replication */ 87 int old_state; 88 MigrationIncomingState *mis = migration_incoming_get_current(); 89 Error *local_err = NULL; 90 91 /* Can not do failover during the process of VM's loading VMstate, Or 92 * it will break the secondary VM. 93 */ 94 if (vmstate_loading) { 95 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 96 FAILOVER_STATUS_RELAUNCH); 97 if (old_state != FAILOVER_STATUS_ACTIVE) { 98 error_report("Unknown error while do failover for secondary VM," 99 "old_state: %s", FailoverStatus_str(old_state)); 100 } 101 return; 102 } 103 104 migrate_set_state(&mis->state, MIGRATION_STATUS_COLO, 105 MIGRATION_STATUS_COMPLETED); 106 107 replication_stop_all(true, &local_err); 108 if (local_err) { 109 error_report_err(local_err); 110 local_err = NULL; 111 } 112 113 /* Notify all filters of all NIC to do checkpoint */ 114 colo_notify_filters_event(COLO_EVENT_FAILOVER, &local_err); 115 if (local_err) { 116 error_report_err(local_err); 117 } 118 119 if (!autostart) { 120 error_report("\"-S\" qemu option will be ignored in secondary side"); 121 /* recover runstate to normal migration finish state */ 122 autostart = true; 123 } 124 /* 125 * Make sure COLO incoming thread not block in recv or send, 126 * If mis->from_src_file and mis->to_src_file use the same fd, 127 * The second shutdown() will return -1, we ignore this value, 128 * It is harmless. 129 */ 130 if (mis->from_src_file) { 131 qemu_file_shutdown(mis->from_src_file); 132 } 133 if (mis->to_src_file) { 134 qemu_file_shutdown(mis->to_src_file); 135 } 136 137 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 138 FAILOVER_STATUS_COMPLETED); 139 if (old_state != FAILOVER_STATUS_ACTIVE) { 140 error_report("Incorrect state (%s) while doing failover for " 141 "secondary VM", FailoverStatus_str(old_state)); 142 return; 143 } 144 /* Notify COLO incoming thread that failover work is finished */ 145 qemu_sem_post(&mis->colo_incoming_sem); 146 147 /* For Secondary VM, jump to incoming co */ 148 if (mis->migration_incoming_co) { 149 qemu_coroutine_enter(mis->migration_incoming_co); 150 } 151 } 152 153 static void primary_vm_do_failover(void) 154 { 155 MigrationState *s = migrate_get_current(); 156 int old_state; 157 Error *local_err = NULL; 158 159 migrate_set_state(&s->state, MIGRATION_STATUS_COLO, 160 MIGRATION_STATUS_COMPLETED); 161 /* 162 * kick COLO thread which might wait at 163 * qemu_sem_wait(&s->colo_checkpoint_sem). 164 */ 165 colo_checkpoint_notify(s); 166 167 /* 168 * Wake up COLO thread which may blocked in recv() or send(), 169 * The s->rp_state.from_dst_file and s->to_dst_file may use the 170 * same fd, but we still shutdown the fd for twice, it is harmless. 171 */ 172 if (s->to_dst_file) { 173 qemu_file_shutdown(s->to_dst_file); 174 } 175 if (s->rp_state.from_dst_file) { 176 qemu_file_shutdown(s->rp_state.from_dst_file); 177 } 178 179 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 180 FAILOVER_STATUS_COMPLETED); 181 if (old_state != FAILOVER_STATUS_ACTIVE) { 182 error_report("Incorrect state (%s) while doing failover for Primary VM", 183 FailoverStatus_str(old_state)); 184 return; 185 } 186 187 replication_stop_all(true, &local_err); 188 if (local_err) { 189 error_report_err(local_err); 190 local_err = NULL; 191 } 192 193 /* Notify COLO thread that failover work is finished */ 194 qemu_sem_post(&s->colo_exit_sem); 195 } 196 197 COLOMode get_colo_mode(void) 198 { 199 if (migration_in_colo_state()) { 200 return COLO_MODE_PRIMARY; 201 } else if (migration_incoming_in_colo_state()) { 202 return COLO_MODE_SECONDARY; 203 } else { 204 return COLO_MODE_NONE; 205 } 206 } 207 208 void colo_do_failover(void) 209 { 210 /* Make sure VM stopped while failover happened. */ 211 if (!colo_runstate_is_stopped()) { 212 vm_stop_force_state(RUN_STATE_COLO); 213 } 214 215 switch (last_colo_mode = get_colo_mode()) { 216 case COLO_MODE_PRIMARY: 217 primary_vm_do_failover(); 218 break; 219 case COLO_MODE_SECONDARY: 220 secondary_vm_do_failover(); 221 break; 222 default: 223 error_report("colo_do_failover failed because the colo mode" 224 " could not be obtained"); 225 } 226 } 227 228 void qmp_xen_set_replication(bool enable, bool primary, 229 bool has_failover, bool failover, 230 Error **errp) 231 { 232 ReplicationMode mode = primary ? 233 REPLICATION_MODE_PRIMARY : 234 REPLICATION_MODE_SECONDARY; 235 236 if (has_failover && enable) { 237 error_setg(errp, "Parameter 'failover' is only for" 238 " stopping replication"); 239 return; 240 } 241 242 if (enable) { 243 replication_start_all(mode, errp); 244 } else { 245 if (!has_failover) { 246 failover = NULL; 247 } 248 replication_stop_all(failover, failover ? NULL : errp); 249 } 250 } 251 252 ReplicationStatus *qmp_query_xen_replication_status(Error **errp) 253 { 254 Error *err = NULL; 255 ReplicationStatus *s = g_new0(ReplicationStatus, 1); 256 257 replication_get_error_all(&err); 258 if (err) { 259 s->error = true; 260 s->desc = g_strdup(error_get_pretty(err)); 261 } else { 262 s->error = false; 263 } 264 265 error_free(err); 266 return s; 267 } 268 269 void qmp_xen_colo_do_checkpoint(Error **errp) 270 { 271 Error *err = NULL; 272 273 replication_do_checkpoint_all(&err); 274 if (err) { 275 error_propagate(errp, err); 276 return; 277 } 278 /* Notify all filters of all NIC to do checkpoint */ 279 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, errp); 280 } 281 282 COLOStatus *qmp_query_colo_status(Error **errp) 283 { 284 COLOStatus *s = g_new0(COLOStatus, 1); 285 286 s->mode = get_colo_mode(); 287 s->last_mode = last_colo_mode; 288 289 switch (failover_get_state()) { 290 case FAILOVER_STATUS_NONE: 291 s->reason = COLO_EXIT_REASON_NONE; 292 break; 293 case FAILOVER_STATUS_COMPLETED: 294 s->reason = COLO_EXIT_REASON_REQUEST; 295 break; 296 default: 297 if (migration_in_colo_state()) { 298 s->reason = COLO_EXIT_REASON_PROCESSING; 299 } else { 300 s->reason = COLO_EXIT_REASON_ERROR; 301 } 302 } 303 304 return s; 305 } 306 307 static void colo_send_message(QEMUFile *f, COLOMessage msg, 308 Error **errp) 309 { 310 int ret; 311 312 if (msg >= COLO_MESSAGE__MAX) { 313 error_setg(errp, "%s: Invalid message", __func__); 314 return; 315 } 316 qemu_put_be32(f, msg); 317 qemu_fflush(f); 318 319 ret = qemu_file_get_error(f); 320 if (ret < 0) { 321 error_setg_errno(errp, -ret, "Can't send COLO message"); 322 } 323 trace_colo_send_message(COLOMessage_str(msg)); 324 } 325 326 static void colo_send_message_value(QEMUFile *f, COLOMessage msg, 327 uint64_t value, Error **errp) 328 { 329 Error *local_err = NULL; 330 int ret; 331 332 colo_send_message(f, msg, &local_err); 333 if (local_err) { 334 error_propagate(errp, local_err); 335 return; 336 } 337 qemu_put_be64(f, value); 338 qemu_fflush(f); 339 340 ret = qemu_file_get_error(f); 341 if (ret < 0) { 342 error_setg_errno(errp, -ret, "Failed to send value for message:%s", 343 COLOMessage_str(msg)); 344 } 345 } 346 347 static COLOMessage colo_receive_message(QEMUFile *f, Error **errp) 348 { 349 COLOMessage msg; 350 int ret; 351 352 msg = qemu_get_be32(f); 353 ret = qemu_file_get_error(f); 354 if (ret < 0) { 355 error_setg_errno(errp, -ret, "Can't receive COLO message"); 356 return msg; 357 } 358 if (msg >= COLO_MESSAGE__MAX) { 359 error_setg(errp, "%s: Invalid message", __func__); 360 return msg; 361 } 362 trace_colo_receive_message(COLOMessage_str(msg)); 363 return msg; 364 } 365 366 static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg, 367 Error **errp) 368 { 369 COLOMessage msg; 370 Error *local_err = NULL; 371 372 msg = colo_receive_message(f, &local_err); 373 if (local_err) { 374 error_propagate(errp, local_err); 375 return; 376 } 377 if (msg != expect_msg) { 378 error_setg(errp, "Unexpected COLO message %d, expected %d", 379 msg, expect_msg); 380 } 381 } 382 383 static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg, 384 Error **errp) 385 { 386 Error *local_err = NULL; 387 uint64_t value; 388 int ret; 389 390 colo_receive_check_message(f, expect_msg, &local_err); 391 if (local_err) { 392 error_propagate(errp, local_err); 393 return 0; 394 } 395 396 value = qemu_get_be64(f); 397 ret = qemu_file_get_error(f); 398 if (ret < 0) { 399 error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s", 400 COLOMessage_str(expect_msg)); 401 } 402 return value; 403 } 404 405 static int colo_do_checkpoint_transaction(MigrationState *s, 406 QIOChannelBuffer *bioc, 407 QEMUFile *fb) 408 { 409 Error *local_err = NULL; 410 int ret = -1; 411 412 colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST, 413 &local_err); 414 if (local_err) { 415 goto out; 416 } 417 418 colo_receive_check_message(s->rp_state.from_dst_file, 419 COLO_MESSAGE_CHECKPOINT_REPLY, &local_err); 420 if (local_err) { 421 goto out; 422 } 423 /* Reset channel-buffer directly */ 424 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL); 425 bioc->usage = 0; 426 427 qemu_mutex_lock_iothread(); 428 if (failover_get_state() != FAILOVER_STATUS_NONE) { 429 qemu_mutex_unlock_iothread(); 430 goto out; 431 } 432 vm_stop_force_state(RUN_STATE_COLO); 433 qemu_mutex_unlock_iothread(); 434 trace_colo_vm_state_change("run", "stop"); 435 /* 436 * Failover request bh could be called after vm_stop_force_state(), 437 * So we need check failover_request_is_active() again. 438 */ 439 if (failover_get_state() != FAILOVER_STATUS_NONE) { 440 goto out; 441 } 442 qemu_mutex_lock_iothread(); 443 444 replication_do_checkpoint_all(&local_err); 445 if (local_err) { 446 qemu_mutex_unlock_iothread(); 447 goto out; 448 } 449 450 colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err); 451 if (local_err) { 452 qemu_mutex_unlock_iothread(); 453 goto out; 454 } 455 /* Note: device state is saved into buffer */ 456 ret = qemu_save_device_state(fb); 457 458 qemu_mutex_unlock_iothread(); 459 if (ret < 0) { 460 goto out; 461 } 462 463 if (migrate_auto_converge()) { 464 mig_throttle_counter_reset(); 465 } 466 /* 467 * Only save VM's live state, which not including device state. 468 * TODO: We may need a timeout mechanism to prevent COLO process 469 * to be blocked here. 470 */ 471 qemu_savevm_live_state(s->to_dst_file); 472 473 qemu_fflush(fb); 474 475 /* 476 * We need the size of the VMstate data in Secondary side, 477 * With which we can decide how much data should be read. 478 */ 479 colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE, 480 bioc->usage, &local_err); 481 if (local_err) { 482 goto out; 483 } 484 485 qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage); 486 qemu_fflush(s->to_dst_file); 487 ret = qemu_file_get_error(s->to_dst_file); 488 if (ret < 0) { 489 goto out; 490 } 491 492 colo_receive_check_message(s->rp_state.from_dst_file, 493 COLO_MESSAGE_VMSTATE_RECEIVED, &local_err); 494 if (local_err) { 495 goto out; 496 } 497 498 qemu_event_reset(&s->colo_checkpoint_event); 499 colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err); 500 if (local_err) { 501 goto out; 502 } 503 504 colo_receive_check_message(s->rp_state.from_dst_file, 505 COLO_MESSAGE_VMSTATE_LOADED, &local_err); 506 if (local_err) { 507 goto out; 508 } 509 510 ret = 0; 511 512 qemu_mutex_lock_iothread(); 513 vm_start(); 514 qemu_mutex_unlock_iothread(); 515 trace_colo_vm_state_change("stop", "run"); 516 517 out: 518 if (local_err) { 519 error_report_err(local_err); 520 } 521 return ret; 522 } 523 524 static void colo_compare_notify_checkpoint(Notifier *notifier, void *data) 525 { 526 colo_checkpoint_notify(data); 527 } 528 529 static void colo_process_checkpoint(MigrationState *s) 530 { 531 QIOChannelBuffer *bioc; 532 QEMUFile *fb = NULL; 533 Error *local_err = NULL; 534 int ret; 535 536 if (get_colo_mode() != COLO_MODE_PRIMARY) { 537 error_report("COLO mode must be COLO_MODE_PRIMARY"); 538 return; 539 } 540 541 failover_init_state(); 542 543 s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file); 544 if (!s->rp_state.from_dst_file) { 545 error_report("Open QEMUFile from_dst_file failed"); 546 goto out; 547 } 548 549 packets_compare_notifier.notify = colo_compare_notify_checkpoint; 550 colo_compare_register_notifier(&packets_compare_notifier); 551 552 /* 553 * Wait for Secondary finish loading VM states and enter COLO 554 * restore. 555 */ 556 colo_receive_check_message(s->rp_state.from_dst_file, 557 COLO_MESSAGE_CHECKPOINT_READY, &local_err); 558 if (local_err) { 559 goto out; 560 } 561 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 562 fb = qemu_file_new_output(QIO_CHANNEL(bioc)); 563 object_unref(OBJECT(bioc)); 564 565 qemu_mutex_lock_iothread(); 566 replication_start_all(REPLICATION_MODE_PRIMARY, &local_err); 567 if (local_err) { 568 qemu_mutex_unlock_iothread(); 569 goto out; 570 } 571 572 vm_start(); 573 qemu_mutex_unlock_iothread(); 574 trace_colo_vm_state_change("stop", "run"); 575 576 timer_mod(s->colo_delay_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) + 577 migrate_checkpoint_delay()); 578 579 while (s->state == MIGRATION_STATUS_COLO) { 580 if (failover_get_state() != FAILOVER_STATUS_NONE) { 581 error_report("failover request"); 582 goto out; 583 } 584 585 qemu_event_wait(&s->colo_checkpoint_event); 586 587 if (s->state != MIGRATION_STATUS_COLO) { 588 goto out; 589 } 590 ret = colo_do_checkpoint_transaction(s, bioc, fb); 591 if (ret < 0) { 592 goto out; 593 } 594 } 595 596 out: 597 /* Throw the unreported error message after exited from loop */ 598 if (local_err) { 599 error_report_err(local_err); 600 } 601 602 if (fb) { 603 qemu_fclose(fb); 604 } 605 606 /* 607 * There are only two reasons we can get here, some error happened 608 * or the user triggered failover. 609 */ 610 switch (failover_get_state()) { 611 case FAILOVER_STATUS_COMPLETED: 612 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 613 COLO_EXIT_REASON_REQUEST); 614 break; 615 default: 616 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 617 COLO_EXIT_REASON_ERROR); 618 } 619 620 /* Hope this not to be too long to wait here */ 621 qemu_sem_wait(&s->colo_exit_sem); 622 qemu_sem_destroy(&s->colo_exit_sem); 623 624 /* 625 * It is safe to unregister notifier after failover finished. 626 * Besides, colo_delay_timer and colo_checkpoint_sem can't be 627 * released before unregister notifier, or there will be use-after-free 628 * error. 629 */ 630 colo_compare_unregister_notifier(&packets_compare_notifier); 631 timer_free(s->colo_delay_timer); 632 qemu_event_destroy(&s->colo_checkpoint_event); 633 634 /* 635 * Must be called after failover BH is completed, 636 * Or the failover BH may shutdown the wrong fd that 637 * re-used by other threads after we release here. 638 */ 639 if (s->rp_state.from_dst_file) { 640 qemu_fclose(s->rp_state.from_dst_file); 641 s->rp_state.from_dst_file = NULL; 642 } 643 } 644 645 void migrate_start_colo_process(MigrationState *s) 646 { 647 qemu_mutex_unlock_iothread(); 648 qemu_event_init(&s->colo_checkpoint_event, false); 649 s->colo_delay_timer = timer_new_ms(QEMU_CLOCK_HOST, 650 colo_checkpoint_notify, s); 651 652 qemu_sem_init(&s->colo_exit_sem, 0); 653 colo_process_checkpoint(s); 654 qemu_mutex_lock_iothread(); 655 } 656 657 static void colo_incoming_process_checkpoint(MigrationIncomingState *mis, 658 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 659 { 660 uint64_t total_size; 661 uint64_t value; 662 Error *local_err = NULL; 663 int ret; 664 665 qemu_mutex_lock_iothread(); 666 vm_stop_force_state(RUN_STATE_COLO); 667 qemu_mutex_unlock_iothread(); 668 trace_colo_vm_state_change("run", "stop"); 669 670 /* FIXME: This is unnecessary for periodic checkpoint mode */ 671 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY, 672 &local_err); 673 if (local_err) { 674 error_propagate(errp, local_err); 675 return; 676 } 677 678 colo_receive_check_message(mis->from_src_file, 679 COLO_MESSAGE_VMSTATE_SEND, &local_err); 680 if (local_err) { 681 error_propagate(errp, local_err); 682 return; 683 } 684 685 qemu_mutex_lock_iothread(); 686 cpu_synchronize_all_states(); 687 ret = qemu_loadvm_state_main(mis->from_src_file, mis); 688 qemu_mutex_unlock_iothread(); 689 690 if (ret < 0) { 691 error_setg(errp, "Load VM's live state (ram) error"); 692 return; 693 } 694 695 value = colo_receive_message_value(mis->from_src_file, 696 COLO_MESSAGE_VMSTATE_SIZE, &local_err); 697 if (local_err) { 698 error_propagate(errp, local_err); 699 return; 700 } 701 702 /* 703 * Read VM device state data into channel buffer, 704 * It's better to re-use the memory allocated. 705 * Here we need to handle the channel buffer directly. 706 */ 707 if (value > bioc->capacity) { 708 bioc->capacity = value; 709 bioc->data = g_realloc(bioc->data, bioc->capacity); 710 } 711 total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value); 712 if (total_size != value) { 713 error_setg(errp, "Got %" PRIu64 " VMState data, less than expected" 714 " %" PRIu64, total_size, value); 715 return; 716 } 717 bioc->usage = total_size; 718 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL); 719 720 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED, 721 &local_err); 722 if (local_err) { 723 error_propagate(errp, local_err); 724 return; 725 } 726 727 qemu_mutex_lock_iothread(); 728 vmstate_loading = true; 729 colo_flush_ram_cache(); 730 ret = qemu_load_device_state(fb); 731 if (ret < 0) { 732 error_setg(errp, "COLO: load device state failed"); 733 vmstate_loading = false; 734 qemu_mutex_unlock_iothread(); 735 return; 736 } 737 738 replication_get_error_all(&local_err); 739 if (local_err) { 740 error_propagate(errp, local_err); 741 vmstate_loading = false; 742 qemu_mutex_unlock_iothread(); 743 return; 744 } 745 746 /* discard colo disk buffer */ 747 replication_do_checkpoint_all(&local_err); 748 if (local_err) { 749 error_propagate(errp, local_err); 750 vmstate_loading = false; 751 qemu_mutex_unlock_iothread(); 752 return; 753 } 754 /* Notify all filters of all NIC to do checkpoint */ 755 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, &local_err); 756 757 if (local_err) { 758 error_propagate(errp, local_err); 759 vmstate_loading = false; 760 qemu_mutex_unlock_iothread(); 761 return; 762 } 763 764 vmstate_loading = false; 765 vm_start(); 766 qemu_mutex_unlock_iothread(); 767 trace_colo_vm_state_change("stop", "run"); 768 769 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 770 return; 771 } 772 773 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED, 774 &local_err); 775 error_propagate(errp, local_err); 776 } 777 778 static void colo_wait_handle_message(MigrationIncomingState *mis, 779 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 780 { 781 COLOMessage msg; 782 Error *local_err = NULL; 783 784 msg = colo_receive_message(mis->from_src_file, &local_err); 785 if (local_err) { 786 error_propagate(errp, local_err); 787 return; 788 } 789 790 switch (msg) { 791 case COLO_MESSAGE_CHECKPOINT_REQUEST: 792 colo_incoming_process_checkpoint(mis, fb, bioc, errp); 793 break; 794 default: 795 error_setg(errp, "Got unknown COLO message: %d", msg); 796 break; 797 } 798 } 799 800 void colo_shutdown(void) 801 { 802 MigrationIncomingState *mis = NULL; 803 MigrationState *s = NULL; 804 805 switch (get_colo_mode()) { 806 case COLO_MODE_PRIMARY: 807 s = migrate_get_current(); 808 qemu_event_set(&s->colo_checkpoint_event); 809 qemu_sem_post(&s->colo_exit_sem); 810 break; 811 case COLO_MODE_SECONDARY: 812 mis = migration_incoming_get_current(); 813 qemu_sem_post(&mis->colo_incoming_sem); 814 break; 815 default: 816 break; 817 } 818 } 819 820 void *colo_process_incoming_thread(void *opaque) 821 { 822 MigrationIncomingState *mis = opaque; 823 QEMUFile *fb = NULL; 824 QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */ 825 Error *local_err = NULL; 826 827 rcu_register_thread(); 828 qemu_sem_init(&mis->colo_incoming_sem, 0); 829 830 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 831 MIGRATION_STATUS_COLO); 832 833 if (get_colo_mode() != COLO_MODE_SECONDARY) { 834 error_report("COLO mode must be COLO_MODE_SECONDARY"); 835 return NULL; 836 } 837 838 failover_init_state(); 839 840 mis->to_src_file = qemu_file_get_return_path(mis->from_src_file); 841 if (!mis->to_src_file) { 842 error_report("COLO incoming thread: Open QEMUFile to_src_file failed"); 843 goto out; 844 } 845 /* 846 * Note: the communication between Primary side and Secondary side 847 * should be sequential, we set the fd to unblocked in migration incoming 848 * coroutine, and here we are in the COLO incoming thread, so it is ok to 849 * set the fd back to blocked. 850 */ 851 qemu_file_set_blocking(mis->from_src_file, true); 852 853 colo_incoming_start_dirty_log(); 854 855 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 856 fb = qemu_file_new_input(QIO_CHANNEL(bioc)); 857 object_unref(OBJECT(bioc)); 858 859 qemu_mutex_lock_iothread(); 860 replication_start_all(REPLICATION_MODE_SECONDARY, &local_err); 861 if (local_err) { 862 qemu_mutex_unlock_iothread(); 863 goto out; 864 } 865 vm_start(); 866 qemu_mutex_unlock_iothread(); 867 trace_colo_vm_state_change("stop", "run"); 868 869 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY, 870 &local_err); 871 if (local_err) { 872 goto out; 873 } 874 875 while (mis->state == MIGRATION_STATUS_COLO) { 876 colo_wait_handle_message(mis, fb, bioc, &local_err); 877 if (local_err) { 878 error_report_err(local_err); 879 break; 880 } 881 882 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 883 failover_set_state(FAILOVER_STATUS_RELAUNCH, 884 FAILOVER_STATUS_NONE); 885 failover_request_active(NULL); 886 break; 887 } 888 889 if (failover_get_state() != FAILOVER_STATUS_NONE) { 890 error_report("failover request"); 891 break; 892 } 893 } 894 895 out: 896 /* 897 * There are only two reasons we can get here, some error happened 898 * or the user triggered failover. 899 */ 900 switch (failover_get_state()) { 901 case FAILOVER_STATUS_COMPLETED: 902 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 903 COLO_EXIT_REASON_REQUEST); 904 break; 905 default: 906 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 907 COLO_EXIT_REASON_ERROR); 908 } 909 910 if (fb) { 911 qemu_fclose(fb); 912 } 913 914 /* Hope this not to be too long to loop here */ 915 qemu_sem_wait(&mis->colo_incoming_sem); 916 qemu_sem_destroy(&mis->colo_incoming_sem); 917 918 rcu_unregister_thread(); 919 return NULL; 920 } 921