Merge remote-tracking branch 'remotes/vivier/tags/trivial-branch-for-6.2-pull-request...
[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 #include "migration/ram.h"
30 #ifdef CONFIG_REPLICATION
31 #include "block/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 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 qemu_event_reset(&s->colo_checkpoint_event);
495 colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err);
496 if (local_err) {
497 goto out;
498 }
499
500 colo_receive_check_message(s->rp_state.from_dst_file,
501 COLO_MESSAGE_VMSTATE_LOADED, &local_err);
502 if (local_err) {
503 goto out;
504 }
505
506 ret = 0;
507
508 qemu_mutex_lock_iothread();
509 vm_start();
510 qemu_mutex_unlock_iothread();
511 trace_colo_vm_state_change("stop", "run");
512
513 out:
514 if (local_err) {
515 error_report_err(local_err);
516 }
517 return ret;
518 }
519
520 static void colo_compare_notify_checkpoint(Notifier *notifier, void *data)
521 {
522 colo_checkpoint_notify(data);
523 }
524
525 static void colo_process_checkpoint(MigrationState *s)
526 {
527 QIOChannelBuffer *bioc;
528 QEMUFile *fb = NULL;
529 int64_t current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
530 Error *local_err = NULL;
531 int ret;
532
533 last_colo_mode = get_colo_mode();
534 if (last_colo_mode != COLO_MODE_PRIMARY) {
535 error_report("COLO mode must be COLO_MODE_PRIMARY");
536 return;
537 }
538
539 failover_init_state();
540
541 s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
542 if (!s->rp_state.from_dst_file) {
543 error_report("Open QEMUFile from_dst_file failed");
544 goto out;
545 }
546
547 packets_compare_notifier.notify = colo_compare_notify_checkpoint;
548 colo_compare_register_notifier(&packets_compare_notifier);
549
550 /*
551 * Wait for Secondary finish loading VM states and enter COLO
552 * restore.
553 */
554 colo_receive_check_message(s->rp_state.from_dst_file,
555 COLO_MESSAGE_CHECKPOINT_READY, &local_err);
556 if (local_err) {
557 goto out;
558 }
559 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
560 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
561 object_unref(OBJECT(bioc));
562
563 qemu_mutex_lock_iothread();
564 #ifdef CONFIG_REPLICATION
565 replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
566 if (local_err) {
567 qemu_mutex_unlock_iothread();
568 goto out;
569 }
570 #else
571 abort();
572 #endif
573
574 vm_start();
575 qemu_mutex_unlock_iothread();
576 trace_colo_vm_state_change("stop", "run");
577
578 timer_mod(s->colo_delay_timer,
579 current_time + s->parameters.x_checkpoint_delay);
580
581 while (s->state == MIGRATION_STATUS_COLO) {
582 if (failover_get_state() != FAILOVER_STATUS_NONE) {
583 error_report("failover request");
584 goto out;
585 }
586
587 qemu_event_wait(&s->colo_checkpoint_event);
588
589 if (s->state != MIGRATION_STATUS_COLO) {
590 goto out;
591 }
592 ret = colo_do_checkpoint_transaction(s, bioc, fb);
593 if (ret < 0) {
594 goto out;
595 }
596 }
597
598 out:
599 /* Throw the unreported error message after exited from loop */
600 if (local_err) {
601 error_report_err(local_err);
602 }
603
604 if (fb) {
605 qemu_fclose(fb);
606 }
607
608 /*
609 * There are only two reasons we can get here, some error happened
610 * or the user triggered failover.
611 */
612 switch (failover_get_state()) {
613 case FAILOVER_STATUS_COMPLETED:
614 qapi_event_send_colo_exit(COLO_MODE_PRIMARY,
615 COLO_EXIT_REASON_REQUEST);
616 break;
617 default:
618 qapi_event_send_colo_exit(COLO_MODE_PRIMARY,
619 COLO_EXIT_REASON_ERROR);
620 }
621
622 /* Hope this not to be too long to wait here */
623 qemu_sem_wait(&s->colo_exit_sem);
624 qemu_sem_destroy(&s->colo_exit_sem);
625
626 /*
627 * It is safe to unregister notifier after failover finished.
628 * Besides, colo_delay_timer and colo_checkpoint_sem can't be
629 * released before unregister notifier, or there will be use-after-free
630 * error.
631 */
632 colo_compare_unregister_notifier(&packets_compare_notifier);
633 timer_free(s->colo_delay_timer);
634 qemu_event_destroy(&s->colo_checkpoint_event);
635
636 /*
637 * Must be called after failover BH is completed,
638 * Or the failover BH may shutdown the wrong fd that
639 * re-used by other threads after we release here.
640 */
641 if (s->rp_state.from_dst_file) {
642 qemu_fclose(s->rp_state.from_dst_file);
643 }
644 }
645
646 void colo_checkpoint_notify(void *opaque)
647 {
648 MigrationState *s = opaque;
649 int64_t next_notify_time;
650
651 qemu_event_set(&s->colo_checkpoint_event);
652 s->colo_checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
653 next_notify_time = s->colo_checkpoint_time +
654 s->parameters.x_checkpoint_delay;
655 timer_mod(s->colo_delay_timer, next_notify_time);
656 }
657
658 void migrate_start_colo_process(MigrationState *s)
659 {
660 qemu_mutex_unlock_iothread();
661 qemu_event_init(&s->colo_checkpoint_event, false);
662 s->colo_delay_timer = timer_new_ms(QEMU_CLOCK_HOST,
663 colo_checkpoint_notify, s);
664
665 qemu_sem_init(&s->colo_exit_sem, 0);
666 migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
667 MIGRATION_STATUS_COLO);
668 colo_process_checkpoint(s);
669 qemu_mutex_lock_iothread();
670 }
671
672 static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
673 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp)
674 {
675 uint64_t total_size;
676 uint64_t value;
677 Error *local_err = NULL;
678 int ret;
679
680 qemu_mutex_lock_iothread();
681 vm_stop_force_state(RUN_STATE_COLO);
682 trace_colo_vm_state_change("run", "stop");
683 qemu_mutex_unlock_iothread();
684
685 /* FIXME: This is unnecessary for periodic checkpoint mode */
686 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY,
687 &local_err);
688 if (local_err) {
689 error_propagate(errp, local_err);
690 return;
691 }
692
693 colo_receive_check_message(mis->from_src_file,
694 COLO_MESSAGE_VMSTATE_SEND, &local_err);
695 if (local_err) {
696 error_propagate(errp, local_err);
697 return;
698 }
699
700 qemu_mutex_lock_iothread();
701 cpu_synchronize_all_states();
702 ret = qemu_loadvm_state_main(mis->from_src_file, mis);
703 qemu_mutex_unlock_iothread();
704
705 if (ret < 0) {
706 error_setg(errp, "Load VM's live state (ram) error");
707 return;
708 }
709
710 value = colo_receive_message_value(mis->from_src_file,
711 COLO_MESSAGE_VMSTATE_SIZE, &local_err);
712 if (local_err) {
713 error_propagate(errp, local_err);
714 return;
715 }
716
717 /*
718 * Read VM device state data into channel buffer,
719 * It's better to re-use the memory allocated.
720 * Here we need to handle the channel buffer directly.
721 */
722 if (value > bioc->capacity) {
723 bioc->capacity = value;
724 bioc->data = g_realloc(bioc->data, bioc->capacity);
725 }
726 total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value);
727 if (total_size != value) {
728 error_setg(errp, "Got %" PRIu64 " VMState data, less than expected"
729 " %" PRIu64, total_size, value);
730 return;
731 }
732 bioc->usage = total_size;
733 qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
734
735 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED,
736 &local_err);
737 if (local_err) {
738 error_propagate(errp, local_err);
739 return;
740 }
741
742 qemu_mutex_lock_iothread();
743 vmstate_loading = true;
744 colo_flush_ram_cache();
745 ret = qemu_load_device_state(fb);
746 if (ret < 0) {
747 error_setg(errp, "COLO: load device state failed");
748 vmstate_loading = false;
749 qemu_mutex_unlock_iothread();
750 return;
751 }
752
753 #ifdef CONFIG_REPLICATION
754 replication_get_error_all(&local_err);
755 if (local_err) {
756 error_propagate(errp, local_err);
757 vmstate_loading = false;
758 qemu_mutex_unlock_iothread();
759 return;
760 }
761
762 /* discard colo disk buffer */
763 replication_do_checkpoint_all(&local_err);
764 if (local_err) {
765 error_propagate(errp, local_err);
766 vmstate_loading = false;
767 qemu_mutex_unlock_iothread();
768 return;
769 }
770 #else
771 abort();
772 #endif
773 /* Notify all filters of all NIC to do checkpoint */
774 colo_notify_filters_event(COLO_EVENT_CHECKPOINT, &local_err);
775
776 if (local_err) {
777 error_propagate(errp, local_err);
778 vmstate_loading = false;
779 qemu_mutex_unlock_iothread();
780 return;
781 }
782
783 vmstate_loading = false;
784 vm_start();
785 trace_colo_vm_state_change("stop", "run");
786 qemu_mutex_unlock_iothread();
787
788 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) {
789 return;
790 }
791
792 colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
793 &local_err);
794 error_propagate(errp, local_err);
795 }
796
797 static void colo_wait_handle_message(MigrationIncomingState *mis,
798 QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp)
799 {
800 COLOMessage msg;
801 Error *local_err = NULL;
802
803 msg = colo_receive_message(mis->from_src_file, &local_err);
804 if (local_err) {
805 error_propagate(errp, local_err);
806 return;
807 }
808
809 switch (msg) {
810 case COLO_MESSAGE_CHECKPOINT_REQUEST:
811 colo_incoming_process_checkpoint(mis, fb, bioc, errp);
812 break;
813 default:
814 error_setg(errp, "Got unknown COLO message: %d", msg);
815 break;
816 }
817 }
818
819 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 last_colo_mode = get_colo_mode();
833 if (last_colo_mode != COLO_MODE_SECONDARY) {
834 error_report("COLO mode must be COLO_MODE_SECONDARY");
835 return NULL;
836 }
837
838 failover_init_state();
839
840 mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
841 if (!mis->to_src_file) {
842 error_report("COLO incoming thread: Open QEMUFile to_src_file failed");
843 goto out;
844 }
845 /*
846 * Note: the communication between Primary side and Secondary side
847 * should be sequential, we set the fd to unblocked in migration incoming
848 * coroutine, and here we are in the COLO incoming thread, so it is ok to
849 * set the fd back to blocked.
850 */
851 qemu_file_set_blocking(mis->from_src_file, true);
852
853 colo_incoming_start_dirty_log();
854
855 bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
856 fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
857 object_unref(OBJECT(bioc));
858
859 qemu_mutex_lock_iothread();
860 #ifdef CONFIG_REPLICATION
861 replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
862 if (local_err) {
863 qemu_mutex_unlock_iothread();
864 goto out;
865 }
866 #else
867 abort();
868 #endif
869 vm_start();
870 trace_colo_vm_state_change("stop", "run");
871 qemu_mutex_unlock_iothread();
872
873 colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
874 &local_err);
875 if (local_err) {
876 goto out;
877 }
878
879 while (mis->state == MIGRATION_STATUS_COLO) {
880 colo_wait_handle_message(mis, fb, bioc, &local_err);
881 if (local_err) {
882 error_report_err(local_err);
883 break;
884 }
885
886 if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) {
887 failover_set_state(FAILOVER_STATUS_RELAUNCH,
888 FAILOVER_STATUS_NONE);
889 failover_request_active(NULL);
890 break;
891 }
892
893 if (failover_get_state() != FAILOVER_STATUS_NONE) {
894 error_report("failover request");
895 break;
896 }
897 }
898
899 out:
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 }