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 "qemu-file-channel.h" 18 #include "migration.h" 19 #include "qemu-file.h" 20 #include "savevm.h" 21 #include "migration/colo.h" 22 #include "block.h" 23 #include "io/channel-buffer.h" 24 #include "trace.h" 25 #include "qemu/error-report.h" 26 #include "qemu/main-loop.h" 27 #include "qemu/rcu.h" 28 #include "migration/failover.h" 29 #include "migration/ram.h" 30 #ifdef CONFIG_REPLICATION 31 #include "replication.h" 32 #endif 33 #include "net/colo-compare.h" 34 #include "net/colo.h" 35 #include "block/block.h" 36 #include "qapi/qapi-events-migration.h" 37 #include "qapi/qmp/qerror.h" 38 #include "sysemu/cpus.h" 39 #include "sysemu/runstate.h" 40 #include "net/filter.h" 41 42 static bool vmstate_loading; 43 static Notifier packets_compare_notifier; 44 45 /* User need to know colo mode after COLO failover */ 46 static COLOMode last_colo_mode; 47 48 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024) 49 50 bool migration_in_colo_state(void) 51 { 52 MigrationState *s = migrate_get_current(); 53 54 return (s->state == MIGRATION_STATUS_COLO); 55 } 56 57 bool migration_incoming_in_colo_state(void) 58 { 59 MigrationIncomingState *mis = migration_incoming_get_current(); 60 61 return mis && (mis->state == MIGRATION_STATUS_COLO); 62 } 63 64 static bool colo_runstate_is_stopped(void) 65 { 66 return runstate_check(RUN_STATE_COLO) || !runstate_is_running(); 67 } 68 69 static void secondary_vm_do_failover(void) 70 { 71 /* COLO needs enable block-replication */ 72 #ifdef CONFIG_REPLICATION 73 int old_state; 74 MigrationIncomingState *mis = migration_incoming_get_current(); 75 Error *local_err = NULL; 76 77 /* Can not do failover during the process of VM's loading VMstate, Or 78 * it will break the secondary VM. 79 */ 80 if (vmstate_loading) { 81 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 82 FAILOVER_STATUS_RELAUNCH); 83 if (old_state != FAILOVER_STATUS_ACTIVE) { 84 error_report("Unknown error while do failover for secondary VM," 85 "old_state: %s", FailoverStatus_str(old_state)); 86 } 87 return; 88 } 89 90 migrate_set_state(&mis->state, MIGRATION_STATUS_COLO, 91 MIGRATION_STATUS_COMPLETED); 92 93 replication_stop_all(true, &local_err); 94 if (local_err) { 95 error_report_err(local_err); 96 local_err = NULL; 97 } 98 99 /* Notify all filters of all NIC to do checkpoint */ 100 colo_notify_filters_event(COLO_EVENT_FAILOVER, &local_err); 101 if (local_err) { 102 error_report_err(local_err); 103 } 104 105 if (!autostart) { 106 error_report("\"-S\" qemu option will be ignored in secondary side"); 107 /* recover runstate to normal migration finish state */ 108 autostart = true; 109 } 110 /* 111 * Make sure COLO incoming thread not block in recv or send, 112 * If mis->from_src_file and mis->to_src_file use the same fd, 113 * The second shutdown() will return -1, we ignore this value, 114 * It is harmless. 115 */ 116 if (mis->from_src_file) { 117 qemu_file_shutdown(mis->from_src_file); 118 } 119 if (mis->to_src_file) { 120 qemu_file_shutdown(mis->to_src_file); 121 } 122 123 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 124 FAILOVER_STATUS_COMPLETED); 125 if (old_state != FAILOVER_STATUS_ACTIVE) { 126 error_report("Incorrect state (%s) while doing failover for " 127 "secondary VM", FailoverStatus_str(old_state)); 128 return; 129 } 130 /* Notify COLO incoming thread that failover work is finished */ 131 qemu_sem_post(&mis->colo_incoming_sem); 132 133 /* For Secondary VM, jump to incoming co */ 134 if (mis->migration_incoming_co) { 135 qemu_coroutine_enter(mis->migration_incoming_co); 136 } 137 #else 138 abort(); 139 #endif 140 } 141 142 static void primary_vm_do_failover(void) 143 { 144 #ifdef CONFIG_REPLICATION 145 MigrationState *s = migrate_get_current(); 146 int old_state; 147 Error *local_err = NULL; 148 149 migrate_set_state(&s->state, MIGRATION_STATUS_COLO, 150 MIGRATION_STATUS_COMPLETED); 151 /* 152 * kick COLO thread which might wait at 153 * qemu_sem_wait(&s->colo_checkpoint_sem). 154 */ 155 colo_checkpoint_notify(migrate_get_current()); 156 157 /* 158 * Wake up COLO thread which may blocked in recv() or send(), 159 * The s->rp_state.from_dst_file and s->to_dst_file may use the 160 * same fd, but we still shutdown the fd for twice, it is harmless. 161 */ 162 if (s->to_dst_file) { 163 qemu_file_shutdown(s->to_dst_file); 164 } 165 if (s->rp_state.from_dst_file) { 166 qemu_file_shutdown(s->rp_state.from_dst_file); 167 } 168 169 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 170 FAILOVER_STATUS_COMPLETED); 171 if (old_state != FAILOVER_STATUS_ACTIVE) { 172 error_report("Incorrect state (%s) while doing failover for Primary VM", 173 FailoverStatus_str(old_state)); 174 return; 175 } 176 177 replication_stop_all(true, &local_err); 178 if (local_err) { 179 error_report_err(local_err); 180 local_err = NULL; 181 } 182 183 /* Notify COLO thread that failover work is finished */ 184 qemu_sem_post(&s->colo_exit_sem); 185 #else 186 abort(); 187 #endif 188 } 189 190 COLOMode get_colo_mode(void) 191 { 192 if (migration_in_colo_state()) { 193 return COLO_MODE_PRIMARY; 194 } else if (migration_incoming_in_colo_state()) { 195 return COLO_MODE_SECONDARY; 196 } else { 197 return COLO_MODE_NONE; 198 } 199 } 200 201 void colo_do_failover(void) 202 { 203 /* Make sure VM stopped while failover happened. */ 204 if (!colo_runstate_is_stopped()) { 205 vm_stop_force_state(RUN_STATE_COLO); 206 } 207 208 switch (get_colo_mode()) { 209 case COLO_MODE_PRIMARY: 210 primary_vm_do_failover(); 211 break; 212 case COLO_MODE_SECONDARY: 213 secondary_vm_do_failover(); 214 break; 215 default: 216 error_report("colo_do_failover failed because the colo mode" 217 " could not be obtained"); 218 } 219 } 220 221 #ifdef CONFIG_REPLICATION 222 void qmp_xen_set_replication(bool enable, bool primary, 223 bool has_failover, bool failover, 224 Error **errp) 225 { 226 ReplicationMode mode = primary ? 227 REPLICATION_MODE_PRIMARY : 228 REPLICATION_MODE_SECONDARY; 229 230 if (has_failover && enable) { 231 error_setg(errp, "Parameter 'failover' is only for" 232 " stopping replication"); 233 return; 234 } 235 236 if (enable) { 237 replication_start_all(mode, errp); 238 } else { 239 if (!has_failover) { 240 failover = NULL; 241 } 242 replication_stop_all(failover, failover ? NULL : errp); 243 } 244 } 245 246 ReplicationStatus *qmp_query_xen_replication_status(Error **errp) 247 { 248 Error *err = NULL; 249 ReplicationStatus *s = g_new0(ReplicationStatus, 1); 250 251 replication_get_error_all(&err); 252 if (err) { 253 s->error = true; 254 s->has_desc = true; 255 s->desc = g_strdup(error_get_pretty(err)); 256 } else { 257 s->error = false; 258 } 259 260 error_free(err); 261 return s; 262 } 263 264 void qmp_xen_colo_do_checkpoint(Error **errp) 265 { 266 Error *err = NULL; 267 268 replication_do_checkpoint_all(&err); 269 if (err) { 270 error_propagate(errp, err); 271 return; 272 } 273 /* Notify all filters of all NIC to do checkpoint */ 274 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, errp); 275 } 276 #endif 277 278 COLOStatus *qmp_query_colo_status(Error **errp) 279 { 280 COLOStatus *s = g_new0(COLOStatus, 1); 281 282 s->mode = get_colo_mode(); 283 s->last_mode = last_colo_mode; 284 285 switch (failover_get_state()) { 286 case FAILOVER_STATUS_NONE: 287 s->reason = COLO_EXIT_REASON_NONE; 288 break; 289 case FAILOVER_STATUS_COMPLETED: 290 s->reason = COLO_EXIT_REASON_REQUEST; 291 break; 292 default: 293 if (migration_in_colo_state()) { 294 s->reason = COLO_EXIT_REASON_PROCESSING; 295 } else { 296 s->reason = COLO_EXIT_REASON_ERROR; 297 } 298 } 299 300 return s; 301 } 302 303 static void colo_send_message(QEMUFile *f, COLOMessage msg, 304 Error **errp) 305 { 306 int ret; 307 308 if (msg >= COLO_MESSAGE__MAX) { 309 error_setg(errp, "%s: Invalid message", __func__); 310 return; 311 } 312 qemu_put_be32(f, msg); 313 qemu_fflush(f); 314 315 ret = qemu_file_get_error(f); 316 if (ret < 0) { 317 error_setg_errno(errp, -ret, "Can't send COLO message"); 318 } 319 trace_colo_send_message(COLOMessage_str(msg)); 320 } 321 322 static void colo_send_message_value(QEMUFile *f, COLOMessage msg, 323 uint64_t value, Error **errp) 324 { 325 Error *local_err = NULL; 326 int ret; 327 328 colo_send_message(f, msg, &local_err); 329 if (local_err) { 330 error_propagate(errp, local_err); 331 return; 332 } 333 qemu_put_be64(f, value); 334 qemu_fflush(f); 335 336 ret = qemu_file_get_error(f); 337 if (ret < 0) { 338 error_setg_errno(errp, -ret, "Failed to send value for message:%s", 339 COLOMessage_str(msg)); 340 } 341 } 342 343 static COLOMessage colo_receive_message(QEMUFile *f, Error **errp) 344 { 345 COLOMessage msg; 346 int ret; 347 348 msg = qemu_get_be32(f); 349 ret = qemu_file_get_error(f); 350 if (ret < 0) { 351 error_setg_errno(errp, -ret, "Can't receive COLO message"); 352 return msg; 353 } 354 if (msg >= COLO_MESSAGE__MAX) { 355 error_setg(errp, "%s: Invalid message", __func__); 356 return msg; 357 } 358 trace_colo_receive_message(COLOMessage_str(msg)); 359 return msg; 360 } 361 362 static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg, 363 Error **errp) 364 { 365 COLOMessage msg; 366 Error *local_err = NULL; 367 368 msg = colo_receive_message(f, &local_err); 369 if (local_err) { 370 error_propagate(errp, local_err); 371 return; 372 } 373 if (msg != expect_msg) { 374 error_setg(errp, "Unexpected COLO message %d, expected %d", 375 msg, expect_msg); 376 } 377 } 378 379 static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg, 380 Error **errp) 381 { 382 Error *local_err = NULL; 383 uint64_t value; 384 int ret; 385 386 colo_receive_check_message(f, expect_msg, &local_err); 387 if (local_err) { 388 error_propagate(errp, local_err); 389 return 0; 390 } 391 392 value = qemu_get_be64(f); 393 ret = qemu_file_get_error(f); 394 if (ret < 0) { 395 error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s", 396 COLOMessage_str(expect_msg)); 397 } 398 return value; 399 } 400 401 static int colo_do_checkpoint_transaction(MigrationState *s, 402 QIOChannelBuffer *bioc, 403 QEMUFile *fb) 404 { 405 Error *local_err = NULL; 406 int ret = -1; 407 408 colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST, 409 &local_err); 410 if (local_err) { 411 goto out; 412 } 413 414 colo_receive_check_message(s->rp_state.from_dst_file, 415 COLO_MESSAGE_CHECKPOINT_REPLY, &local_err); 416 if (local_err) { 417 goto out; 418 } 419 /* Reset channel-buffer directly */ 420 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL); 421 bioc->usage = 0; 422 423 qemu_mutex_lock_iothread(); 424 if (failover_get_state() != FAILOVER_STATUS_NONE) { 425 qemu_mutex_unlock_iothread(); 426 goto out; 427 } 428 vm_stop_force_state(RUN_STATE_COLO); 429 qemu_mutex_unlock_iothread(); 430 trace_colo_vm_state_change("run", "stop"); 431 /* 432 * Failover request bh could be called after vm_stop_force_state(), 433 * So we need check failover_request_is_active() again. 434 */ 435 if (failover_get_state() != FAILOVER_STATUS_NONE) { 436 goto out; 437 } 438 439 /* Disable block migration */ 440 migrate_set_block_enabled(false, &local_err); 441 if (local_err) { 442 goto out; 443 } 444 qemu_mutex_lock_iothread(); 445 446 #ifdef CONFIG_REPLICATION 447 replication_do_checkpoint_all(&local_err); 448 if (local_err) { 449 qemu_mutex_unlock_iothread(); 450 goto out; 451 } 452 #else 453 abort(); 454 #endif 455 456 colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err); 457 if (local_err) { 458 qemu_mutex_unlock_iothread(); 459 goto out; 460 } 461 /* Note: device state is saved into buffer */ 462 ret = qemu_save_device_state(fb); 463 464 qemu_mutex_unlock_iothread(); 465 if (ret < 0) { 466 goto out; 467 } 468 /* 469 * Only save VM's live state, which not including device state. 470 * TODO: We may need a timeout mechanism to prevent COLO process 471 * to be blocked here. 472 */ 473 qemu_savevm_live_state(s->to_dst_file); 474 475 qemu_fflush(fb); 476 477 /* 478 * We need the size of the VMstate data in Secondary side, 479 * With which we can decide how much data should be read. 480 */ 481 colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE, 482 bioc->usage, &local_err); 483 if (local_err) { 484 goto out; 485 } 486 487 qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage); 488 qemu_fflush(s->to_dst_file); 489 ret = qemu_file_get_error(s->to_dst_file); 490 if (ret < 0) { 491 goto out; 492 } 493 494 colo_receive_check_message(s->rp_state.from_dst_file, 495 COLO_MESSAGE_VMSTATE_RECEIVED, &local_err); 496 if (local_err) { 497 goto out; 498 } 499 500 qemu_event_reset(&s->colo_checkpoint_event); 501 colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err); 502 if (local_err) { 503 goto out; 504 } 505 506 colo_receive_check_message(s->rp_state.from_dst_file, 507 COLO_MESSAGE_VMSTATE_LOADED, &local_err); 508 if (local_err) { 509 goto out; 510 } 511 512 ret = 0; 513 514 qemu_mutex_lock_iothread(); 515 vm_start(); 516 qemu_mutex_unlock_iothread(); 517 trace_colo_vm_state_change("stop", "run"); 518 519 out: 520 if (local_err) { 521 error_report_err(local_err); 522 } 523 return ret; 524 } 525 526 static void colo_compare_notify_checkpoint(Notifier *notifier, void *data) 527 { 528 colo_checkpoint_notify(data); 529 } 530 531 static void colo_process_checkpoint(MigrationState *s) 532 { 533 QIOChannelBuffer *bioc; 534 QEMUFile *fb = NULL; 535 int64_t current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST); 536 Error *local_err = NULL; 537 int ret; 538 539 last_colo_mode = get_colo_mode(); 540 if (last_colo_mode != COLO_MODE_PRIMARY) { 541 error_report("COLO mode must be COLO_MODE_PRIMARY"); 542 return; 543 } 544 545 failover_init_state(); 546 547 s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file); 548 if (!s->rp_state.from_dst_file) { 549 error_report("Open QEMUFile from_dst_file failed"); 550 goto out; 551 } 552 553 packets_compare_notifier.notify = colo_compare_notify_checkpoint; 554 colo_compare_register_notifier(&packets_compare_notifier); 555 556 /* 557 * Wait for Secondary finish loading VM states and enter COLO 558 * restore. 559 */ 560 colo_receive_check_message(s->rp_state.from_dst_file, 561 COLO_MESSAGE_CHECKPOINT_READY, &local_err); 562 if (local_err) { 563 goto out; 564 } 565 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 566 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 567 object_unref(OBJECT(bioc)); 568 569 qemu_mutex_lock_iothread(); 570 #ifdef CONFIG_REPLICATION 571 replication_start_all(REPLICATION_MODE_PRIMARY, &local_err); 572 if (local_err) { 573 qemu_mutex_unlock_iothread(); 574 goto out; 575 } 576 #else 577 abort(); 578 #endif 579 580 vm_start(); 581 qemu_mutex_unlock_iothread(); 582 trace_colo_vm_state_change("stop", "run"); 583 584 timer_mod(s->colo_delay_timer, 585 current_time + s->parameters.x_checkpoint_delay); 586 587 while (s->state == MIGRATION_STATUS_COLO) { 588 if (failover_get_state() != FAILOVER_STATUS_NONE) { 589 error_report("failover request"); 590 goto out; 591 } 592 593 qemu_event_wait(&s->colo_checkpoint_event); 594 595 if (s->state != MIGRATION_STATUS_COLO) { 596 goto out; 597 } 598 ret = colo_do_checkpoint_transaction(s, bioc, fb); 599 if (ret < 0) { 600 goto out; 601 } 602 } 603 604 out: 605 /* Throw the unreported error message after exited from loop */ 606 if (local_err) { 607 error_report_err(local_err); 608 } 609 610 if (fb) { 611 qemu_fclose(fb); 612 } 613 614 /* 615 * There are only two reasons we can get here, some error happened 616 * or the user triggered failover. 617 */ 618 switch (failover_get_state()) { 619 case FAILOVER_STATUS_COMPLETED: 620 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 621 COLO_EXIT_REASON_REQUEST); 622 break; 623 default: 624 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 625 COLO_EXIT_REASON_ERROR); 626 } 627 628 /* Hope this not to be too long to wait here */ 629 qemu_sem_wait(&s->colo_exit_sem); 630 qemu_sem_destroy(&s->colo_exit_sem); 631 632 /* 633 * It is safe to unregister notifier after failover finished. 634 * Besides, colo_delay_timer and colo_checkpoint_sem can't be 635 * released before unregister notifier, or there will be use-after-free 636 * error. 637 */ 638 colo_compare_unregister_notifier(&packets_compare_notifier); 639 timer_del(s->colo_delay_timer); 640 timer_free(s->colo_delay_timer); 641 qemu_event_destroy(&s->colo_checkpoint_event); 642 643 /* 644 * Must be called after failover BH is completed, 645 * Or the failover BH may shutdown the wrong fd that 646 * re-used by other threads after we release here. 647 */ 648 if (s->rp_state.from_dst_file) { 649 qemu_fclose(s->rp_state.from_dst_file); 650 } 651 } 652 653 void colo_checkpoint_notify(void *opaque) 654 { 655 MigrationState *s = opaque; 656 int64_t next_notify_time; 657 658 qemu_event_set(&s->colo_checkpoint_event); 659 s->colo_checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST); 660 next_notify_time = s->colo_checkpoint_time + 661 s->parameters.x_checkpoint_delay; 662 timer_mod(s->colo_delay_timer, next_notify_time); 663 } 664 665 void migrate_start_colo_process(MigrationState *s) 666 { 667 qemu_mutex_unlock_iothread(); 668 qemu_event_init(&s->colo_checkpoint_event, false); 669 s->colo_delay_timer = timer_new_ms(QEMU_CLOCK_HOST, 670 colo_checkpoint_notify, s); 671 672 qemu_sem_init(&s->colo_exit_sem, 0); 673 migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, 674 MIGRATION_STATUS_COLO); 675 colo_process_checkpoint(s); 676 qemu_mutex_lock_iothread(); 677 } 678 679 static void colo_incoming_process_checkpoint(MigrationIncomingState *mis, 680 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 681 { 682 uint64_t total_size; 683 uint64_t value; 684 Error *local_err = NULL; 685 int ret; 686 687 qemu_mutex_lock_iothread(); 688 vm_stop_force_state(RUN_STATE_COLO); 689 trace_colo_vm_state_change("run", "stop"); 690 qemu_mutex_unlock_iothread(); 691 692 /* FIXME: This is unnecessary for periodic checkpoint mode */ 693 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY, 694 &local_err); 695 if (local_err) { 696 error_propagate(errp, local_err); 697 return; 698 } 699 700 colo_receive_check_message(mis->from_src_file, 701 COLO_MESSAGE_VMSTATE_SEND, &local_err); 702 if (local_err) { 703 error_propagate(errp, local_err); 704 return; 705 } 706 707 qemu_mutex_lock_iothread(); 708 cpu_synchronize_all_states(); 709 ret = qemu_loadvm_state_main(mis->from_src_file, mis); 710 qemu_mutex_unlock_iothread(); 711 712 if (ret < 0) { 713 error_setg(errp, "Load VM's live state (ram) error"); 714 return; 715 } 716 717 value = colo_receive_message_value(mis->from_src_file, 718 COLO_MESSAGE_VMSTATE_SIZE, &local_err); 719 if (local_err) { 720 error_propagate(errp, local_err); 721 return; 722 } 723 724 /* 725 * Read VM device state data into channel buffer, 726 * It's better to re-use the memory allocated. 727 * Here we need to handle the channel buffer directly. 728 */ 729 if (value > bioc->capacity) { 730 bioc->capacity = value; 731 bioc->data = g_realloc(bioc->data, bioc->capacity); 732 } 733 total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value); 734 if (total_size != value) { 735 error_setg(errp, "Got %" PRIu64 " VMState data, less than expected" 736 " %" PRIu64, total_size, value); 737 return; 738 } 739 bioc->usage = total_size; 740 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL); 741 742 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED, 743 &local_err); 744 if (local_err) { 745 error_propagate(errp, local_err); 746 return; 747 } 748 749 qemu_mutex_lock_iothread(); 750 vmstate_loading = true; 751 colo_flush_ram_cache(); 752 ret = qemu_load_device_state(fb); 753 if (ret < 0) { 754 error_setg(errp, "COLO: load device state failed"); 755 vmstate_loading = false; 756 qemu_mutex_unlock_iothread(); 757 return; 758 } 759 760 #ifdef CONFIG_REPLICATION 761 replication_get_error_all(&local_err); 762 if (local_err) { 763 error_propagate(errp, local_err); 764 vmstate_loading = false; 765 qemu_mutex_unlock_iothread(); 766 return; 767 } 768 769 /* discard colo disk buffer */ 770 replication_do_checkpoint_all(&local_err); 771 if (local_err) { 772 error_propagate(errp, local_err); 773 vmstate_loading = false; 774 qemu_mutex_unlock_iothread(); 775 return; 776 } 777 #else 778 abort(); 779 #endif 780 /* Notify all filters of all NIC to do checkpoint */ 781 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, &local_err); 782 783 if (local_err) { 784 error_propagate(errp, local_err); 785 vmstate_loading = false; 786 qemu_mutex_unlock_iothread(); 787 return; 788 } 789 790 vmstate_loading = false; 791 vm_start(); 792 trace_colo_vm_state_change("stop", "run"); 793 qemu_mutex_unlock_iothread(); 794 795 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 796 return; 797 } 798 799 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED, 800 &local_err); 801 error_propagate(errp, local_err); 802 } 803 804 static void colo_wait_handle_message(MigrationIncomingState *mis, 805 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 806 { 807 COLOMessage msg; 808 Error *local_err = NULL; 809 810 msg = colo_receive_message(mis->from_src_file, &local_err); 811 if (local_err) { 812 error_propagate(errp, local_err); 813 return; 814 } 815 816 switch (msg) { 817 case COLO_MESSAGE_CHECKPOINT_REQUEST: 818 colo_incoming_process_checkpoint(mis, fb, bioc, errp); 819 break; 820 default: 821 error_setg(errp, "Got unknown COLO message: %d", msg); 822 break; 823 } 824 } 825 826 void *colo_process_incoming_thread(void *opaque) 827 { 828 MigrationIncomingState *mis = opaque; 829 QEMUFile *fb = NULL; 830 QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */ 831 Error *local_err = NULL; 832 833 rcu_register_thread(); 834 qemu_sem_init(&mis->colo_incoming_sem, 0); 835 836 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 837 MIGRATION_STATUS_COLO); 838 839 last_colo_mode = get_colo_mode(); 840 if (last_colo_mode != COLO_MODE_SECONDARY) { 841 error_report("COLO mode must be COLO_MODE_SECONDARY"); 842 return NULL; 843 } 844 845 failover_init_state(); 846 847 mis->to_src_file = qemu_file_get_return_path(mis->from_src_file); 848 if (!mis->to_src_file) { 849 error_report("COLO incoming thread: Open QEMUFile to_src_file failed"); 850 goto out; 851 } 852 /* 853 * Note: the communication between Primary side and Secondary side 854 * should be sequential, we set the fd to unblocked in migration incoming 855 * coroutine, and here we are in the COLO incoming thread, so it is ok to 856 * set the fd back to blocked. 857 */ 858 qemu_file_set_blocking(mis->from_src_file, true); 859 860 colo_incoming_start_dirty_log(); 861 862 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 863 fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); 864 object_unref(OBJECT(bioc)); 865 866 qemu_mutex_lock_iothread(); 867 #ifdef CONFIG_REPLICATION 868 replication_start_all(REPLICATION_MODE_SECONDARY, &local_err); 869 if (local_err) { 870 qemu_mutex_unlock_iothread(); 871 goto out; 872 } 873 #else 874 abort(); 875 #endif 876 vm_start(); 877 trace_colo_vm_state_change("stop", "run"); 878 qemu_mutex_unlock_iothread(); 879 880 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY, 881 &local_err); 882 if (local_err) { 883 goto out; 884 } 885 886 while (mis->state == MIGRATION_STATUS_COLO) { 887 colo_wait_handle_message(mis, fb, bioc, &local_err); 888 if (local_err) { 889 error_report_err(local_err); 890 break; 891 } 892 893 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 894 failover_set_state(FAILOVER_STATUS_RELAUNCH, 895 FAILOVER_STATUS_NONE); 896 failover_request_active(NULL); 897 break; 898 } 899 900 if (failover_get_state() != FAILOVER_STATUS_NONE) { 901 error_report("failover request"); 902 break; 903 } 904 } 905 906 out: 907 /* 908 * There are only two reasons we can get here, some error happened 909 * or the user triggered failover. 910 */ 911 switch (failover_get_state()) { 912 case FAILOVER_STATUS_COMPLETED: 913 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 914 COLO_EXIT_REASON_REQUEST); 915 break; 916 default: 917 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 918 COLO_EXIT_REASON_ERROR); 919 } 920 921 if (fb) { 922 qemu_fclose(fb); 923 } 924 925 /* Hope this not to be too long to loop here */ 926 qemu_sem_wait(&mis->colo_incoming_sem); 927 qemu_sem_destroy(&mis->colo_incoming_sem); 928 /* Must be called after failover BH is completed */ 929 if (mis->to_src_file) { 930 qemu_fclose(mis->to_src_file); 931 mis->to_src_file = NULL; 932 } 933 934 rcu_unregister_thread(); 935 return NULL; 936 } 937