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