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 "io/channel-buffer.h" 22 #include "trace.h" 23 #include "qemu/error-report.h" 24 #include "qemu/main-loop.h" 25 #include "qemu/rcu.h" 26 #include "migration/failover.h" 27 #include "migration/ram.h" 28 #include "block/replication.h" 29 #include "net/colo-compare.h" 30 #include "net/colo.h" 31 #include "block/block.h" 32 #include "qapi/qapi-events-migration.h" 33 #include "sysemu/cpus.h" 34 #include "sysemu/runstate.h" 35 #include "net/filter.h" 36 #include "options.h" 37 38 static bool vmstate_loading; 39 static Notifier packets_compare_notifier; 40 41 /* User need to know colo mode after COLO failover */ 42 static COLOMode last_colo_mode; 43 44 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024) 45 46 bool migration_in_colo_state(void) 47 { 48 MigrationState *s = migrate_get_current(); 49 50 return (s->state == MIGRATION_STATUS_COLO); 51 } 52 53 bool migration_incoming_in_colo_state(void) 54 { 55 MigrationIncomingState *mis = migration_incoming_get_current(); 56 57 return mis && (mis->state == MIGRATION_STATUS_COLO); 58 } 59 60 static bool colo_runstate_is_stopped(void) 61 { 62 return runstate_check(RUN_STATE_COLO) || !runstate_is_running(); 63 } 64 65 static void colo_checkpoint_notify(void) 66 { 67 MigrationState *s = migrate_get_current(); 68 int64_t next_notify_time; 69 70 qemu_event_set(&s->colo_checkpoint_event); 71 s->colo_checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST); 72 next_notify_time = s->colo_checkpoint_time + migrate_checkpoint_delay(); 73 timer_mod(s->colo_delay_timer, next_notify_time); 74 } 75 76 static void colo_checkpoint_notify_timer(void *opaque) 77 { 78 colo_checkpoint_notify(); 79 } 80 81 void colo_checkpoint_delay_set(void) 82 { 83 if (migration_in_colo_state()) { 84 colo_checkpoint_notify(); 85 } 86 } 87 88 static void secondary_vm_do_failover(void) 89 { 90 /* COLO needs enable block-replication */ 91 int old_state; 92 MigrationIncomingState *mis = migration_incoming_get_current(); 93 Error *local_err = NULL; 94 95 /* Can not do failover during the process of VM's loading VMstate, Or 96 * it will break the secondary VM. 97 */ 98 if (vmstate_loading) { 99 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 100 FAILOVER_STATUS_RELAUNCH); 101 if (old_state != FAILOVER_STATUS_ACTIVE) { 102 error_report("Unknown error while do failover for secondary VM," 103 "old_state: %s", FailoverStatus_str(old_state)); 104 } 105 return; 106 } 107 108 migrate_set_state(&mis->state, MIGRATION_STATUS_COLO, 109 MIGRATION_STATUS_COMPLETED); 110 111 replication_stop_all(true, &local_err); 112 if (local_err) { 113 error_report_err(local_err); 114 local_err = NULL; 115 } 116 117 /* Notify all filters of all NIC to do checkpoint */ 118 colo_notify_filters_event(COLO_EVENT_FAILOVER, &local_err); 119 if (local_err) { 120 error_report_err(local_err); 121 } 122 123 if (!autostart) { 124 error_report("\"-S\" qemu option will be ignored in secondary side"); 125 /* recover runstate to normal migration finish state */ 126 autostart = true; 127 } 128 /* 129 * Make sure COLO incoming thread not block in recv or send, 130 * If mis->from_src_file and mis->to_src_file use the same fd, 131 * The second shutdown() will return -1, we ignore this value, 132 * It is harmless. 133 */ 134 if (mis->from_src_file) { 135 qemu_file_shutdown(mis->from_src_file); 136 } 137 if (mis->to_src_file) { 138 qemu_file_shutdown(mis->to_src_file); 139 } 140 141 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 142 FAILOVER_STATUS_COMPLETED); 143 if (old_state != FAILOVER_STATUS_ACTIVE) { 144 error_report("Incorrect state (%s) while doing failover for " 145 "secondary VM", FailoverStatus_str(old_state)); 146 return; 147 } 148 /* Notify COLO incoming thread that failover work is finished */ 149 qemu_sem_post(&mis->colo_incoming_sem); 150 151 /* For Secondary VM, jump to incoming co */ 152 if (mis->colo_incoming_co) { 153 qemu_coroutine_enter(mis->colo_incoming_co); 154 } 155 } 156 157 static void primary_vm_do_failover(void) 158 { 159 MigrationState *s = migrate_get_current(); 160 int old_state; 161 Error *local_err = NULL; 162 163 migrate_set_state(&s->state, MIGRATION_STATUS_COLO, 164 MIGRATION_STATUS_COMPLETED); 165 /* 166 * kick COLO thread which might wait at 167 * qemu_sem_wait(&s->colo_checkpoint_sem). 168 */ 169 colo_checkpoint_notify(); 170 171 /* 172 * Wake up COLO thread which may blocked in recv() or send(), 173 * The s->rp_state.from_dst_file and s->to_dst_file may use the 174 * same fd, but we still shutdown the fd for twice, it is harmless. 175 */ 176 if (s->to_dst_file) { 177 qemu_file_shutdown(s->to_dst_file); 178 } 179 if (s->rp_state.from_dst_file) { 180 qemu_file_shutdown(s->rp_state.from_dst_file); 181 } 182 183 old_state = failover_set_state(FAILOVER_STATUS_ACTIVE, 184 FAILOVER_STATUS_COMPLETED); 185 if (old_state != FAILOVER_STATUS_ACTIVE) { 186 error_report("Incorrect state (%s) while doing failover for Primary VM", 187 FailoverStatus_str(old_state)); 188 return; 189 } 190 191 replication_stop_all(true, &local_err); 192 if (local_err) { 193 error_report_err(local_err); 194 local_err = NULL; 195 } 196 197 /* Notify COLO thread that failover work is finished */ 198 qemu_sem_post(&s->colo_exit_sem); 199 } 200 201 COLOMode get_colo_mode(void) 202 { 203 if (migration_in_colo_state()) { 204 return COLO_MODE_PRIMARY; 205 } else if (migration_incoming_in_colo_state()) { 206 return COLO_MODE_SECONDARY; 207 } else { 208 return COLO_MODE_NONE; 209 } 210 } 211 212 void colo_do_failover(void) 213 { 214 /* Make sure VM stopped while failover happened. */ 215 if (!colo_runstate_is_stopped()) { 216 vm_stop_force_state(RUN_STATE_COLO); 217 } 218 219 switch (last_colo_mode = get_colo_mode()) { 220 case COLO_MODE_PRIMARY: 221 primary_vm_do_failover(); 222 break; 223 case COLO_MODE_SECONDARY: 224 secondary_vm_do_failover(); 225 break; 226 default: 227 error_report("colo_do_failover failed because the colo mode" 228 " could not be obtained"); 229 } 230 } 231 232 void qmp_xen_set_replication(bool enable, bool primary, 233 bool has_failover, bool failover, 234 Error **errp) 235 { 236 ReplicationMode mode = primary ? 237 REPLICATION_MODE_PRIMARY : 238 REPLICATION_MODE_SECONDARY; 239 240 if (has_failover && enable) { 241 error_setg(errp, "Parameter 'failover' is only for" 242 " stopping replication"); 243 return; 244 } 245 246 if (enable) { 247 replication_start_all(mode, errp); 248 } else { 249 if (!has_failover) { 250 failover = NULL; 251 } 252 replication_stop_all(failover, failover ? NULL : errp); 253 } 254 } 255 256 ReplicationStatus *qmp_query_xen_replication_status(Error **errp) 257 { 258 Error *err = NULL; 259 ReplicationStatus *s = g_new0(ReplicationStatus, 1); 260 261 replication_get_error_all(&err); 262 if (err) { 263 s->error = true; 264 s->desc = g_strdup(error_get_pretty(err)); 265 } else { 266 s->error = false; 267 } 268 269 error_free(err); 270 return s; 271 } 272 273 void qmp_xen_colo_do_checkpoint(Error **errp) 274 { 275 Error *err = NULL; 276 277 replication_do_checkpoint_all(&err); 278 if (err) { 279 error_propagate(errp, err); 280 return; 281 } 282 /* Notify all filters of all NIC to do checkpoint */ 283 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, errp); 284 } 285 286 COLOStatus *qmp_query_colo_status(Error **errp) 287 { 288 COLOStatus *s = g_new0(COLOStatus, 1); 289 290 s->mode = get_colo_mode(); 291 s->last_mode = last_colo_mode; 292 293 switch (failover_get_state()) { 294 case FAILOVER_STATUS_NONE: 295 s->reason = COLO_EXIT_REASON_NONE; 296 break; 297 case FAILOVER_STATUS_COMPLETED: 298 s->reason = COLO_EXIT_REASON_REQUEST; 299 break; 300 default: 301 if (migration_in_colo_state()) { 302 s->reason = COLO_EXIT_REASON_PROCESSING; 303 } else { 304 s->reason = COLO_EXIT_REASON_ERROR; 305 } 306 } 307 308 return s; 309 } 310 311 static void colo_send_message(QEMUFile *f, COLOMessage msg, 312 Error **errp) 313 { 314 int ret; 315 316 if (msg >= COLO_MESSAGE__MAX) { 317 error_setg(errp, "%s: Invalid message", __func__); 318 return; 319 } 320 qemu_put_be32(f, msg); 321 ret = qemu_fflush(f); 322 if (ret < 0) { 323 error_setg_errno(errp, -ret, "Can't send COLO message"); 324 } 325 trace_colo_send_message(COLOMessage_str(msg)); 326 } 327 328 static void colo_send_message_value(QEMUFile *f, COLOMessage msg, 329 uint64_t value, Error **errp) 330 { 331 Error *local_err = NULL; 332 int ret; 333 334 colo_send_message(f, msg, &local_err); 335 if (local_err) { 336 error_propagate(errp, local_err); 337 return; 338 } 339 qemu_put_be64(f, value); 340 ret = qemu_fflush(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 bql_lock(); 428 if (failover_get_state() != FAILOVER_STATUS_NONE) { 429 bql_unlock(); 430 goto out; 431 } 432 vm_stop_force_state(RUN_STATE_COLO); 433 bql_unlock(); 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 bql_lock(); 443 444 replication_do_checkpoint_all(&local_err); 445 if (local_err) { 446 bql_unlock(); 447 goto out; 448 } 449 450 colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err); 451 if (local_err) { 452 bql_unlock(); 453 goto out; 454 } 455 /* Note: device state is saved into buffer */ 456 ret = qemu_save_device_state(fb); 457 458 bql_unlock(); 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 ret = qemu_fflush(s->to_dst_file); 487 if (ret < 0) { 488 goto out; 489 } 490 491 colo_receive_check_message(s->rp_state.from_dst_file, 492 COLO_MESSAGE_VMSTATE_RECEIVED, &local_err); 493 if (local_err) { 494 goto out; 495 } 496 497 qemu_event_reset(&s->colo_checkpoint_event); 498 colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err); 499 if (local_err) { 500 goto out; 501 } 502 503 colo_receive_check_message(s->rp_state.from_dst_file, 504 COLO_MESSAGE_VMSTATE_LOADED, &local_err); 505 if (local_err) { 506 goto out; 507 } 508 509 ret = 0; 510 511 bql_lock(); 512 vm_start(); 513 bql_unlock(); 514 trace_colo_vm_state_change("stop", "run"); 515 516 out: 517 if (local_err) { 518 error_report_err(local_err); 519 } 520 return ret; 521 } 522 523 static void colo_compare_notify_checkpoint(Notifier *notifier, void *data) 524 { 525 colo_checkpoint_notify(); 526 } 527 528 static void colo_process_checkpoint(MigrationState *s) 529 { 530 QIOChannelBuffer *bioc; 531 QEMUFile *fb = NULL; 532 Error *local_err = NULL; 533 int ret; 534 535 if (get_colo_mode() != COLO_MODE_PRIMARY) { 536 error_report("COLO mode must be COLO_MODE_PRIMARY"); 537 return; 538 } 539 540 failover_init_state(); 541 542 s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file); 543 if (!s->rp_state.from_dst_file) { 544 error_report("Open QEMUFile from_dst_file failed"); 545 goto out; 546 } 547 548 packets_compare_notifier.notify = colo_compare_notify_checkpoint; 549 colo_compare_register_notifier(&packets_compare_notifier); 550 551 /* 552 * Wait for Secondary finish loading VM states and enter COLO 553 * restore. 554 */ 555 colo_receive_check_message(s->rp_state.from_dst_file, 556 COLO_MESSAGE_CHECKPOINT_READY, &local_err); 557 if (local_err) { 558 goto out; 559 } 560 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 561 fb = qemu_file_new_output(QIO_CHANNEL(bioc)); 562 object_unref(OBJECT(bioc)); 563 564 bql_lock(); 565 replication_start_all(REPLICATION_MODE_PRIMARY, &local_err); 566 if (local_err) { 567 bql_unlock(); 568 goto out; 569 } 570 571 vm_start(); 572 bql_unlock(); 573 trace_colo_vm_state_change("stop", "run"); 574 575 timer_mod(s->colo_delay_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) + 576 migrate_checkpoint_delay()); 577 578 while (s->state == MIGRATION_STATUS_COLO) { 579 if (failover_get_state() != FAILOVER_STATUS_NONE) { 580 error_report("failover request"); 581 goto out; 582 } 583 584 qemu_event_wait(&s->colo_checkpoint_event); 585 586 if (s->state != MIGRATION_STATUS_COLO) { 587 goto out; 588 } 589 ret = colo_do_checkpoint_transaction(s, bioc, fb); 590 if (ret < 0) { 591 goto out; 592 } 593 } 594 595 out: 596 /* Throw the unreported error message after exited from loop */ 597 if (local_err) { 598 error_report_err(local_err); 599 } 600 601 if (fb) { 602 qemu_fclose(fb); 603 } 604 605 /* 606 * There are only two reasons we can get here, some error happened 607 * or the user triggered failover. 608 */ 609 switch (failover_get_state()) { 610 case FAILOVER_STATUS_COMPLETED: 611 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 612 COLO_EXIT_REASON_REQUEST); 613 break; 614 default: 615 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 616 COLO_EXIT_REASON_ERROR); 617 } 618 619 /* Hope this not to be too long to wait here */ 620 qemu_sem_wait(&s->colo_exit_sem); 621 qemu_sem_destroy(&s->colo_exit_sem); 622 623 /* 624 * It is safe to unregister notifier after failover finished. 625 * Besides, colo_delay_timer and colo_checkpoint_sem can't be 626 * released before unregister notifier, or there will be use-after-free 627 * error. 628 */ 629 colo_compare_unregister_notifier(&packets_compare_notifier); 630 timer_free(s->colo_delay_timer); 631 qemu_event_destroy(&s->colo_checkpoint_event); 632 633 /* 634 * Must be called after failover BH is completed, 635 * Or the failover BH may shutdown the wrong fd that 636 * re-used by other threads after we release here. 637 */ 638 if (s->rp_state.from_dst_file) { 639 qemu_fclose(s->rp_state.from_dst_file); 640 s->rp_state.from_dst_file = NULL; 641 } 642 } 643 644 void migrate_start_colo_process(MigrationState *s) 645 { 646 bql_unlock(); 647 qemu_event_init(&s->colo_checkpoint_event, false); 648 s->colo_delay_timer = timer_new_ms(QEMU_CLOCK_HOST, 649 colo_checkpoint_notify_timer, NULL); 650 651 qemu_sem_init(&s->colo_exit_sem, 0); 652 colo_process_checkpoint(s); 653 bql_lock(); 654 } 655 656 static void colo_incoming_process_checkpoint(MigrationIncomingState *mis, 657 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 658 { 659 uint64_t total_size; 660 uint64_t value; 661 Error *local_err = NULL; 662 int ret; 663 664 bql_lock(); 665 vm_stop_force_state(RUN_STATE_COLO); 666 bql_unlock(); 667 trace_colo_vm_state_change("run", "stop"); 668 669 /* FIXME: This is unnecessary for periodic checkpoint mode */ 670 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY, 671 &local_err); 672 if (local_err) { 673 error_propagate(errp, local_err); 674 return; 675 } 676 677 colo_receive_check_message(mis->from_src_file, 678 COLO_MESSAGE_VMSTATE_SEND, &local_err); 679 if (local_err) { 680 error_propagate(errp, local_err); 681 return; 682 } 683 684 bql_lock(); 685 cpu_synchronize_all_states(); 686 ret = qemu_loadvm_state_main(mis->from_src_file, mis); 687 bql_unlock(); 688 689 if (ret < 0) { 690 error_setg(errp, "Load VM's live state (ram) error"); 691 return; 692 } 693 694 value = colo_receive_message_value(mis->from_src_file, 695 COLO_MESSAGE_VMSTATE_SIZE, &local_err); 696 if (local_err) { 697 error_propagate(errp, local_err); 698 return; 699 } 700 701 /* 702 * Read VM device state data into channel buffer, 703 * It's better to re-use the memory allocated. 704 * Here we need to handle the channel buffer directly. 705 */ 706 if (value > bioc->capacity) { 707 bioc->capacity = value; 708 bioc->data = g_realloc(bioc->data, bioc->capacity); 709 } 710 total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value); 711 if (total_size != value) { 712 error_setg(errp, "Got %" PRIu64 " VMState data, less than expected" 713 " %" PRIu64, total_size, value); 714 return; 715 } 716 bioc->usage = total_size; 717 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL); 718 719 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED, 720 &local_err); 721 if (local_err) { 722 error_propagate(errp, local_err); 723 return; 724 } 725 726 bql_lock(); 727 vmstate_loading = true; 728 colo_flush_ram_cache(); 729 ret = qemu_load_device_state(fb); 730 if (ret < 0) { 731 error_setg(errp, "COLO: load device state failed"); 732 vmstate_loading = false; 733 bql_unlock(); 734 return; 735 } 736 737 replication_get_error_all(&local_err); 738 if (local_err) { 739 error_propagate(errp, local_err); 740 vmstate_loading = false; 741 bql_unlock(); 742 return; 743 } 744 745 /* discard colo disk buffer */ 746 replication_do_checkpoint_all(&local_err); 747 if (local_err) { 748 error_propagate(errp, local_err); 749 vmstate_loading = false; 750 bql_unlock(); 751 return; 752 } 753 /* Notify all filters of all NIC to do checkpoint */ 754 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, &local_err); 755 756 if (local_err) { 757 error_propagate(errp, local_err); 758 vmstate_loading = false; 759 bql_unlock(); 760 return; 761 } 762 763 vmstate_loading = false; 764 vm_start(); 765 bql_unlock(); 766 trace_colo_vm_state_change("stop", "run"); 767 768 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 769 return; 770 } 771 772 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED, 773 &local_err); 774 error_propagate(errp, local_err); 775 } 776 777 static void colo_wait_handle_message(MigrationIncomingState *mis, 778 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 779 { 780 COLOMessage msg; 781 Error *local_err = NULL; 782 783 msg = colo_receive_message(mis->from_src_file, &local_err); 784 if (local_err) { 785 error_propagate(errp, local_err); 786 return; 787 } 788 789 switch (msg) { 790 case COLO_MESSAGE_CHECKPOINT_REQUEST: 791 colo_incoming_process_checkpoint(mis, fb, bioc, errp); 792 break; 793 default: 794 error_setg(errp, "Got unknown COLO message: %d", msg); 795 break; 796 } 797 } 798 799 void colo_shutdown(void) 800 { 801 MigrationIncomingState *mis = NULL; 802 MigrationState *s = NULL; 803 804 switch (get_colo_mode()) { 805 case COLO_MODE_PRIMARY: 806 s = migrate_get_current(); 807 qemu_event_set(&s->colo_checkpoint_event); 808 qemu_sem_post(&s->colo_exit_sem); 809 break; 810 case COLO_MODE_SECONDARY: 811 mis = migration_incoming_get_current(); 812 qemu_sem_post(&mis->colo_incoming_sem); 813 break; 814 default: 815 break; 816 } 817 } 818 819 static void *colo_process_incoming_thread(void *opaque) 820 { 821 MigrationIncomingState *mis = opaque; 822 QEMUFile *fb = NULL; 823 QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */ 824 Error *local_err = NULL; 825 826 rcu_register_thread(); 827 qemu_sem_init(&mis->colo_incoming_sem, 0); 828 829 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 830 MIGRATION_STATUS_COLO); 831 832 if (get_colo_mode() != COLO_MODE_SECONDARY) { 833 error_report("COLO mode must be COLO_MODE_SECONDARY"); 834 return NULL; 835 } 836 837 /* Make sure all file formats throw away their mutable metadata */ 838 bql_lock(); 839 bdrv_activate_all(&local_err); 840 bql_unlock(); 841 if (local_err) { 842 error_report_err(local_err); 843 return NULL; 844 } 845 846 failover_init_state(); 847 848 mis->to_src_file = qemu_file_get_return_path(mis->from_src_file); 849 if (!mis->to_src_file) { 850 error_report("COLO incoming thread: Open QEMUFile to_src_file failed"); 851 goto out; 852 } 853 /* 854 * Note: the communication between Primary side and Secondary side 855 * should be sequential, we set the fd to unblocked in migration incoming 856 * coroutine, and here we are in the COLO incoming thread, so it is ok to 857 * set the fd back to blocked. 858 */ 859 qemu_file_set_blocking(mis->from_src_file, true); 860 861 colo_incoming_start_dirty_log(); 862 863 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 864 fb = qemu_file_new_input(QIO_CHANNEL(bioc)); 865 object_unref(OBJECT(bioc)); 866 867 bql_lock(); 868 replication_start_all(REPLICATION_MODE_SECONDARY, &local_err); 869 if (local_err) { 870 bql_unlock(); 871 goto out; 872 } 873 vm_start(); 874 bql_unlock(); 875 trace_colo_vm_state_change("stop", "run"); 876 877 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY, 878 &local_err); 879 if (local_err) { 880 goto out; 881 } 882 883 while (mis->state == MIGRATION_STATUS_COLO) { 884 colo_wait_handle_message(mis, fb, bioc, &local_err); 885 if (local_err) { 886 error_report_err(local_err); 887 break; 888 } 889 890 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 891 failover_set_state(FAILOVER_STATUS_RELAUNCH, 892 FAILOVER_STATUS_NONE); 893 failover_request_active(NULL); 894 break; 895 } 896 897 if (failover_get_state() != FAILOVER_STATUS_NONE) { 898 error_report("failover request"); 899 break; 900 } 901 } 902 903 out: 904 /* 905 * There are only two reasons we can get here, some error happened 906 * or the user triggered failover. 907 */ 908 switch (failover_get_state()) { 909 case FAILOVER_STATUS_COMPLETED: 910 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 911 COLO_EXIT_REASON_REQUEST); 912 break; 913 default: 914 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 915 COLO_EXIT_REASON_ERROR); 916 } 917 918 if (fb) { 919 qemu_fclose(fb); 920 } 921 922 /* Hope this not to be too long to loop here */ 923 qemu_sem_wait(&mis->colo_incoming_sem); 924 qemu_sem_destroy(&mis->colo_incoming_sem); 925 926 rcu_unregister_thread(); 927 return NULL; 928 } 929 930 void coroutine_fn colo_incoming_co(void) 931 { 932 MigrationIncomingState *mis = migration_incoming_get_current(); 933 QemuThread th; 934 935 assert(bql_locked()); 936 assert(migration_incoming_colo_enabled()); 937 938 qemu_thread_create(&th, MIGRATION_THREAD_DST_COLO, 939 colo_process_incoming_thread, 940 mis, QEMU_THREAD_JOINABLE); 941 942 mis->colo_incoming_co = qemu_coroutine_self(); 943 qemu_coroutine_yield(); 944 mis->colo_incoming_co = NULL; 945 946 bql_unlock(); 947 /* Wait checkpoint incoming thread exit before free resource */ 948 qemu_thread_join(&th); 949 bql_lock(); 950 951 /* We hold the global BQL, so it is safe here */ 952 colo_release_ram_cache(); 953 } 954