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 colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err); 440 if (local_err) { 441 goto out; 442 } 443 444 /* Disable block migration */ 445 migrate_set_block_enabled(false, &local_err); 446 if (local_err) { 447 goto out; 448 } 449 qemu_mutex_lock_iothread(); 450 451 #ifdef CONFIG_REPLICATION 452 replication_do_checkpoint_all(&local_err); 453 if (local_err) { 454 qemu_mutex_unlock_iothread(); 455 goto out; 456 } 457 #else 458 abort(); 459 #endif 460 461 colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err); 462 if (local_err) { 463 qemu_mutex_unlock_iothread(); 464 goto out; 465 } 466 /* Note: device state is saved into buffer */ 467 ret = qemu_save_device_state(fb); 468 469 qemu_mutex_unlock_iothread(); 470 if (ret < 0) { 471 goto out; 472 } 473 /* 474 * Only save VM's live state, which not including device state. 475 * TODO: We may need a timeout mechanism to prevent COLO process 476 * to be blocked here. 477 */ 478 qemu_savevm_live_state(s->to_dst_file); 479 480 qemu_fflush(fb); 481 482 /* 483 * We need the size of the VMstate data in Secondary side, 484 * With which we can decide how much data should be read. 485 */ 486 colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE, 487 bioc->usage, &local_err); 488 if (local_err) { 489 goto out; 490 } 491 492 qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage); 493 qemu_fflush(s->to_dst_file); 494 ret = qemu_file_get_error(s->to_dst_file); 495 if (ret < 0) { 496 goto out; 497 } 498 499 colo_receive_check_message(s->rp_state.from_dst_file, 500 COLO_MESSAGE_VMSTATE_RECEIVED, &local_err); 501 if (local_err) { 502 goto out; 503 } 504 505 colo_receive_check_message(s->rp_state.from_dst_file, 506 COLO_MESSAGE_VMSTATE_LOADED, &local_err); 507 if (local_err) { 508 goto out; 509 } 510 511 ret = 0; 512 513 qemu_mutex_lock_iothread(); 514 vm_start(); 515 qemu_mutex_unlock_iothread(); 516 trace_colo_vm_state_change("stop", "run"); 517 518 out: 519 if (local_err) { 520 error_report_err(local_err); 521 } 522 return ret; 523 } 524 525 static void colo_compare_notify_checkpoint(Notifier *notifier, void *data) 526 { 527 colo_checkpoint_notify(data); 528 } 529 530 static void colo_process_checkpoint(MigrationState *s) 531 { 532 QIOChannelBuffer *bioc; 533 QEMUFile *fb = NULL; 534 int64_t current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST); 535 Error *local_err = NULL; 536 int ret; 537 538 last_colo_mode = get_colo_mode(); 539 if (last_colo_mode != COLO_MODE_PRIMARY) { 540 error_report("COLO mode must be COLO_MODE_PRIMARY"); 541 return; 542 } 543 544 failover_init_state(); 545 546 s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file); 547 if (!s->rp_state.from_dst_file) { 548 error_report("Open QEMUFile from_dst_file failed"); 549 goto out; 550 } 551 552 packets_compare_notifier.notify = colo_compare_notify_checkpoint; 553 colo_compare_register_notifier(&packets_compare_notifier); 554 555 /* 556 * Wait for Secondary finish loading VM states and enter COLO 557 * restore. 558 */ 559 colo_receive_check_message(s->rp_state.from_dst_file, 560 COLO_MESSAGE_CHECKPOINT_READY, &local_err); 561 if (local_err) { 562 goto out; 563 } 564 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 565 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc)); 566 object_unref(OBJECT(bioc)); 567 568 qemu_mutex_lock_iothread(); 569 #ifdef CONFIG_REPLICATION 570 replication_start_all(REPLICATION_MODE_PRIMARY, &local_err); 571 if (local_err) { 572 qemu_mutex_unlock_iothread(); 573 goto out; 574 } 575 #else 576 abort(); 577 #endif 578 579 vm_start(); 580 qemu_mutex_unlock_iothread(); 581 trace_colo_vm_state_change("stop", "run"); 582 583 timer_mod(s->colo_delay_timer, 584 current_time + s->parameters.x_checkpoint_delay); 585 586 while (s->state == MIGRATION_STATUS_COLO) { 587 if (failover_get_state() != FAILOVER_STATUS_NONE) { 588 error_report("failover request"); 589 goto out; 590 } 591 592 qemu_sem_wait(&s->colo_checkpoint_sem); 593 594 if (s->state != MIGRATION_STATUS_COLO) { 595 goto out; 596 } 597 ret = colo_do_checkpoint_transaction(s, bioc, fb); 598 if (ret < 0) { 599 goto out; 600 } 601 } 602 603 out: 604 /* Throw the unreported error message after exited from loop */ 605 if (local_err) { 606 error_report_err(local_err); 607 } 608 609 if (fb) { 610 qemu_fclose(fb); 611 } 612 613 /* 614 * There are only two reasons we can get here, some error happened 615 * or the user triggered failover. 616 */ 617 switch (failover_get_state()) { 618 case FAILOVER_STATUS_COMPLETED: 619 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 620 COLO_EXIT_REASON_REQUEST); 621 break; 622 default: 623 qapi_event_send_colo_exit(COLO_MODE_PRIMARY, 624 COLO_EXIT_REASON_ERROR); 625 } 626 627 /* Hope this not to be too long to wait here */ 628 qemu_sem_wait(&s->colo_exit_sem); 629 qemu_sem_destroy(&s->colo_exit_sem); 630 631 /* 632 * It is safe to unregister notifier after failover finished. 633 * Besides, colo_delay_timer and colo_checkpoint_sem can't be 634 * released befor unregister notifier, or there will be use-after-free 635 * error. 636 */ 637 colo_compare_unregister_notifier(&packets_compare_notifier); 638 timer_del(s->colo_delay_timer); 639 timer_free(s->colo_delay_timer); 640 qemu_sem_destroy(&s->colo_checkpoint_sem); 641 642 /* 643 * Must be called after failover BH is completed, 644 * Or the failover BH may shutdown the wrong fd that 645 * re-used by other threads after we release here. 646 */ 647 if (s->rp_state.from_dst_file) { 648 qemu_fclose(s->rp_state.from_dst_file); 649 } 650 } 651 652 void colo_checkpoint_notify(void *opaque) 653 { 654 MigrationState *s = opaque; 655 int64_t next_notify_time; 656 657 qemu_sem_post(&s->colo_checkpoint_sem); 658 s->colo_checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST); 659 next_notify_time = s->colo_checkpoint_time + 660 s->parameters.x_checkpoint_delay; 661 timer_mod(s->colo_delay_timer, next_notify_time); 662 } 663 664 void migrate_start_colo_process(MigrationState *s) 665 { 666 qemu_mutex_unlock_iothread(); 667 qemu_sem_init(&s->colo_checkpoint_sem, 0); 668 s->colo_delay_timer = timer_new_ms(QEMU_CLOCK_HOST, 669 colo_checkpoint_notify, s); 670 671 qemu_sem_init(&s->colo_exit_sem, 0); 672 migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, 673 MIGRATION_STATUS_COLO); 674 colo_process_checkpoint(s); 675 qemu_mutex_lock_iothread(); 676 } 677 678 static void colo_incoming_process_checkpoint(MigrationIncomingState *mis, 679 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 680 { 681 uint64_t total_size; 682 uint64_t value; 683 Error *local_err = NULL; 684 int ret; 685 686 qemu_mutex_lock_iothread(); 687 vm_stop_force_state(RUN_STATE_COLO); 688 trace_colo_vm_state_change("run", "stop"); 689 qemu_mutex_unlock_iothread(); 690 691 /* FIXME: This is unnecessary for periodic checkpoint mode */ 692 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY, 693 &local_err); 694 if (local_err) { 695 error_propagate(errp, local_err); 696 return; 697 } 698 699 colo_receive_check_message(mis->from_src_file, 700 COLO_MESSAGE_VMSTATE_SEND, &local_err); 701 if (local_err) { 702 error_propagate(errp, local_err); 703 return; 704 } 705 706 qemu_mutex_lock_iothread(); 707 cpu_synchronize_all_pre_loadvm(); 708 ret = qemu_loadvm_state_main(mis->from_src_file, mis); 709 qemu_mutex_unlock_iothread(); 710 711 if (ret < 0) { 712 error_setg(errp, "Load VM's live state (ram) error"); 713 return; 714 } 715 716 value = colo_receive_message_value(mis->from_src_file, 717 COLO_MESSAGE_VMSTATE_SIZE, &local_err); 718 if (local_err) { 719 error_propagate(errp, local_err); 720 return; 721 } 722 723 /* 724 * Read VM device state data into channel buffer, 725 * It's better to re-use the memory allocated. 726 * Here we need to handle the channel buffer directly. 727 */ 728 if (value > bioc->capacity) { 729 bioc->capacity = value; 730 bioc->data = g_realloc(bioc->data, bioc->capacity); 731 } 732 total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value); 733 if (total_size != value) { 734 error_setg(errp, "Got %" PRIu64 " VMState data, less than expected" 735 " %" PRIu64, total_size, value); 736 return; 737 } 738 bioc->usage = total_size; 739 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL); 740 741 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED, 742 &local_err); 743 if (local_err) { 744 error_propagate(errp, local_err); 745 return; 746 } 747 748 qemu_mutex_lock_iothread(); 749 vmstate_loading = true; 750 ret = qemu_load_device_state(fb); 751 if (ret < 0) { 752 error_setg(errp, "COLO: load device state failed"); 753 qemu_mutex_unlock_iothread(); 754 return; 755 } 756 757 #ifdef CONFIG_REPLICATION 758 replication_get_error_all(&local_err); 759 if (local_err) { 760 error_propagate(errp, local_err); 761 qemu_mutex_unlock_iothread(); 762 return; 763 } 764 765 /* discard colo disk buffer */ 766 replication_do_checkpoint_all(&local_err); 767 if (local_err) { 768 error_propagate(errp, local_err); 769 qemu_mutex_unlock_iothread(); 770 return; 771 } 772 #else 773 abort(); 774 #endif 775 /* Notify all filters of all NIC to do checkpoint */ 776 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, &local_err); 777 778 if (local_err) { 779 error_propagate(errp, local_err); 780 qemu_mutex_unlock_iothread(); 781 return; 782 } 783 784 vmstate_loading = false; 785 vm_start(); 786 trace_colo_vm_state_change("stop", "run"); 787 qemu_mutex_unlock_iothread(); 788 789 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) { 790 failover_set_state(FAILOVER_STATUS_RELAUNCH, 791 FAILOVER_STATUS_NONE); 792 failover_request_active(NULL); 793 return; 794 } 795 796 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED, 797 &local_err); 798 if (local_err) { 799 error_propagate(errp, local_err); 800 } 801 } 802 803 static void colo_wait_handle_message(MigrationIncomingState *mis, 804 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp) 805 { 806 COLOMessage msg; 807 Error *local_err = NULL; 808 809 msg = colo_receive_message(mis->from_src_file, &local_err); 810 if (local_err) { 811 error_propagate(errp, local_err); 812 return; 813 } 814 815 switch (msg) { 816 case COLO_MESSAGE_CHECKPOINT_REQUEST: 817 colo_incoming_process_checkpoint(mis, fb, bioc, errp); 818 break; 819 default: 820 error_setg(errp, "Got unknown COLO message: %d", msg); 821 break; 822 } 823 } 824 825 void *colo_process_incoming_thread(void *opaque) 826 { 827 MigrationIncomingState *mis = opaque; 828 QEMUFile *fb = NULL; 829 QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */ 830 Error *local_err = NULL; 831 832 rcu_register_thread(); 833 qemu_sem_init(&mis->colo_incoming_sem, 0); 834 835 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 836 MIGRATION_STATUS_COLO); 837 838 last_colo_mode = get_colo_mode(); 839 if (last_colo_mode != COLO_MODE_SECONDARY) { 840 error_report("COLO mode must be COLO_MODE_SECONDARY"); 841 return NULL; 842 } 843 844 failover_init_state(); 845 846 mis->to_src_file = qemu_file_get_return_path(mis->from_src_file); 847 if (!mis->to_src_file) { 848 error_report("COLO incoming thread: Open QEMUFile to_src_file failed"); 849 goto out; 850 } 851 /* 852 * Note: the communication between Primary side and Secondary side 853 * should be sequential, we set the fd to unblocked in migration incoming 854 * coroutine, and here we are in the COLO incoming thread, so it is ok to 855 * set the fd back to blocked. 856 */ 857 qemu_file_set_blocking(mis->from_src_file, true); 858 859 colo_incoming_start_dirty_log(); 860 861 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); 862 fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); 863 object_unref(OBJECT(bioc)); 864 865 qemu_mutex_lock_iothread(); 866 #ifdef CONFIG_REPLICATION 867 replication_start_all(REPLICATION_MODE_SECONDARY, &local_err); 868 if (local_err) { 869 qemu_mutex_unlock_iothread(); 870 goto out; 871 } 872 #else 873 abort(); 874 #endif 875 vm_start(); 876 trace_colo_vm_state_change("stop", "run"); 877 qemu_mutex_unlock_iothread(); 878 879 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY, 880 &local_err); 881 if (local_err) { 882 goto out; 883 } 884 885 while (mis->state == MIGRATION_STATUS_COLO) { 886 colo_wait_handle_message(mis, fb, bioc, &local_err); 887 if (local_err) { 888 error_report_err(local_err); 889 break; 890 } 891 if (failover_get_state() != FAILOVER_STATUS_NONE) { 892 error_report("failover request"); 893 break; 894 } 895 } 896 897 out: 898 vmstate_loading = false; 899 900 /* 901 * There are only two reasons we can get here, some error happened 902 * or the user triggered failover. 903 */ 904 switch (failover_get_state()) { 905 case FAILOVER_STATUS_COMPLETED: 906 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 907 COLO_EXIT_REASON_REQUEST); 908 break; 909 default: 910 qapi_event_send_colo_exit(COLO_MODE_SECONDARY, 911 COLO_EXIT_REASON_ERROR); 912 } 913 914 if (fb) { 915 qemu_fclose(fb); 916 } 917 918 /* Hope this not to be too long to loop here */ 919 qemu_sem_wait(&mis->colo_incoming_sem); 920 qemu_sem_destroy(&mis->colo_incoming_sem); 921 /* Must be called after failover BH is completed */ 922 if (mis->to_src_file) { 923 qemu_fclose(mis->to_src_file); 924 mis->to_src_file = NULL; 925 } 926 927 rcu_unregister_thread(); 928 return NULL; 929 } 930