4 * Copyright IBM, Corp. 2008
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
16 #include "qemu-common.h"
17 #include "qemu/error-report.h"
18 #include "qemu/main-loop.h"
19 #include "migration/migration.h"
20 #include "migration/qemu-file.h"
21 #include "sysemu/sysemu.h"
22 #include "block/block.h"
23 #include "qapi/qmp/qerror.h"
24 #include "qemu/sockets.h"
26 #include "migration/block.h"
27 #include "qemu/thread.h"
28 #include "qmp-commands.h"
30 #include "qapi/util.h"
31 #include "qapi-event.h"
33 #define MAX_THROTTLE (32 << 20) /* Migration speed throttling */
35 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
37 #define BUFFER_DELAY 100
38 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
40 /* Default compression thread count */
41 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
42 /* Default decompression thread count, usually decompression is at
43 * least 4 times as fast as compression.*/
44 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
45 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
46 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
48 /* Migration XBZRLE default cache size */
49 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
51 static NotifierList migration_state_notifiers =
52 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
54 static bool deferred_incoming;
56 /* When we add fault tolerance, we could have several
57 migrations at once. For now we don't need to add
58 dynamic creation of migration */
61 MigrationState *migrate_get_current(void)
63 static MigrationState current_migration = {
64 .state = MIGRATION_STATUS_NONE,
65 .bandwidth_limit = MAX_THROTTLE,
66 .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
68 .parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] =
69 DEFAULT_MIGRATE_COMPRESS_LEVEL,
70 .parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
71 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT,
72 .parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
73 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
76 return ¤t_migration;
80 static MigrationIncomingState *mis_current;
82 MigrationIncomingState *migration_incoming_get_current(void)
87 MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
89 mis_current = g_malloc0(sizeof(MigrationIncomingState));
90 mis_current->file = f;
91 QLIST_INIT(&mis_current->loadvm_handlers);
96 void migration_incoming_state_destroy(void)
98 loadvm_free_handlers(mis_current);
107 uint8_t runstate[100];
112 static GlobalState global_state;
114 int global_state_store(void)
116 if (!runstate_store((char *)global_state.runstate,
117 sizeof(global_state.runstate))) {
118 error_report("runstate name too big: %s", global_state.runstate);
119 trace_migrate_state_too_big();
125 void global_state_store_running(void)
127 const char *state = RunState_lookup[RUN_STATE_RUNNING];
128 strncpy((char *)global_state.runstate,
129 state, sizeof(global_state.runstate));
132 static bool global_state_received(void)
134 return global_state.received;
137 static RunState global_state_get_runstate(void)
139 return global_state.state;
142 void global_state_set_optional(void)
144 global_state.optional = true;
147 static bool global_state_needed(void *opaque)
149 GlobalState *s = opaque;
150 char *runstate = (char *)s->runstate;
152 /* If it is not optional, it is mandatory */
154 if (s->optional == false) {
158 /* If state is running or paused, it is not needed */
160 if (strcmp(runstate, "running") == 0 ||
161 strcmp(runstate, "paused") == 0) {
165 /* for any other state it is needed */
169 static int global_state_post_load(void *opaque, int version_id)
171 GlobalState *s = opaque;
172 Error *local_err = NULL;
174 char *runstate = (char *)s->runstate;
177 trace_migrate_global_state_post_load(runstate);
179 r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE_MAX,
184 error_report_err(local_err);
193 static void global_state_pre_save(void *opaque)
195 GlobalState *s = opaque;
197 trace_migrate_global_state_pre_save((char *)s->runstate);
198 s->size = strlen((char *)s->runstate) + 1;
201 static const VMStateDescription vmstate_globalstate = {
202 .name = "globalstate",
204 .minimum_version_id = 1,
205 .post_load = global_state_post_load,
206 .pre_save = global_state_pre_save,
207 .needed = global_state_needed,
208 .fields = (VMStateField[]) {
209 VMSTATE_UINT32(size, GlobalState),
210 VMSTATE_BUFFER(runstate, GlobalState),
211 VMSTATE_END_OF_LIST()
215 void register_global_state(void)
217 /* We would use it independently that we receive it */
218 strcpy((char *)&global_state.runstate, "");
219 global_state.received = false;
220 vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
223 static void migrate_generate_event(int new_state)
225 if (migrate_use_events()) {
226 qapi_event_send_migration(new_state, &error_abort);
231 * Called on -incoming with a defer: uri.
232 * The migration can be started later after any parameters have been
235 static void deferred_incoming_migration(Error **errp)
237 if (deferred_incoming) {
238 error_setg(errp, "Incoming migration already deferred");
240 deferred_incoming = true;
243 void qemu_start_incoming_migration(const char *uri, Error **errp)
247 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort);
248 if (!strcmp(uri, "defer")) {
249 deferred_incoming_migration(errp);
250 } else if (strstart(uri, "tcp:", &p)) {
251 tcp_start_incoming_migration(p, errp);
253 } else if (strstart(uri, "rdma:", &p)) {
254 rdma_start_incoming_migration(p, errp);
257 } else if (strstart(uri, "exec:", &p)) {
258 exec_start_incoming_migration(p, errp);
259 } else if (strstart(uri, "unix:", &p)) {
260 unix_start_incoming_migration(p, errp);
261 } else if (strstart(uri, "fd:", &p)) {
262 fd_start_incoming_migration(p, errp);
265 error_setg(errp, "unknown migration protocol: %s", uri);
269 static void process_incoming_migration_co(void *opaque)
271 QEMUFile *f = opaque;
272 Error *local_err = NULL;
275 migration_incoming_state_new(f);
276 migrate_generate_event(MIGRATION_STATUS_ACTIVE);
277 ret = qemu_loadvm_state(f);
280 free_xbzrle_decoded_buf();
281 migration_incoming_state_destroy();
284 migrate_generate_event(MIGRATION_STATUS_FAILED);
285 error_report("load of migration failed: %s", strerror(-ret));
286 migrate_decompress_threads_join();
289 migrate_generate_event(MIGRATION_STATUS_COMPLETED);
290 qemu_announce_self();
292 /* Make sure all file formats flush their mutable metadata */
293 bdrv_invalidate_cache_all(&local_err);
295 error_report_err(local_err);
296 migrate_decompress_threads_join();
300 /* If global state section was not received or we are in running
301 state, we need to obey autostart. Any other state is set with
304 if (!global_state_received() ||
305 global_state_get_runstate() == RUN_STATE_RUNNING) {
309 runstate_set(RUN_STATE_PAUSED);
312 runstate_set(global_state_get_runstate());
314 migrate_decompress_threads_join();
317 void process_incoming_migration(QEMUFile *f)
319 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
320 int fd = qemu_get_fd(f);
323 migrate_decompress_threads_create();
324 qemu_set_nonblock(fd);
325 qemu_coroutine_enter(co, f);
328 /* amount of nanoseconds we are willing to wait for migration to be down.
329 * the choice of nanoseconds is because it is the maximum resolution that
330 * get_clock() can achieve. It is an internal measure. All user-visible
331 * units must be in seconds */
332 static uint64_t max_downtime = 300000000;
334 uint64_t migrate_max_downtime(void)
339 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
341 MigrationCapabilityStatusList *head = NULL;
342 MigrationCapabilityStatusList *caps;
343 MigrationState *s = migrate_get_current();
346 caps = NULL; /* silence compiler warning */
347 for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
349 head = g_malloc0(sizeof(*caps));
352 caps->next = g_malloc0(sizeof(*caps));
356 g_malloc(sizeof(*caps->value));
357 caps->value->capability = i;
358 caps->value->state = s->enabled_capabilities[i];
364 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
366 MigrationParameters *params;
367 MigrationState *s = migrate_get_current();
369 params = g_malloc0(sizeof(*params));
370 params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
371 params->compress_threads =
372 s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
373 params->decompress_threads =
374 s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
379 static void get_xbzrle_cache_stats(MigrationInfo *info)
381 if (migrate_use_xbzrle()) {
382 info->has_xbzrle_cache = true;
383 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
384 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
385 info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
386 info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
387 info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
388 info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate();
389 info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
393 MigrationInfo *qmp_query_migrate(Error **errp)
395 MigrationInfo *info = g_malloc0(sizeof(*info));
396 MigrationState *s = migrate_get_current();
399 case MIGRATION_STATUS_NONE:
400 /* no migration has happened ever */
402 case MIGRATION_STATUS_SETUP:
403 info->has_status = true;
404 info->has_total_time = false;
406 case MIGRATION_STATUS_ACTIVE:
407 case MIGRATION_STATUS_CANCELLING:
408 info->has_status = true;
409 info->has_total_time = true;
410 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
412 info->has_expected_downtime = true;
413 info->expected_downtime = s->expected_downtime;
414 info->has_setup_time = true;
415 info->setup_time = s->setup_time;
417 info->has_ram = true;
418 info->ram = g_malloc0(sizeof(*info->ram));
419 info->ram->transferred = ram_bytes_transferred();
420 info->ram->remaining = ram_bytes_remaining();
421 info->ram->total = ram_bytes_total();
422 info->ram->duplicate = dup_mig_pages_transferred();
423 info->ram->skipped = skipped_mig_pages_transferred();
424 info->ram->normal = norm_mig_pages_transferred();
425 info->ram->normal_bytes = norm_mig_bytes_transferred();
426 info->ram->dirty_pages_rate = s->dirty_pages_rate;
427 info->ram->mbps = s->mbps;
428 info->ram->dirty_sync_count = s->dirty_sync_count;
430 if (blk_mig_active()) {
431 info->has_disk = true;
432 info->disk = g_malloc0(sizeof(*info->disk));
433 info->disk->transferred = blk_mig_bytes_transferred();
434 info->disk->remaining = blk_mig_bytes_remaining();
435 info->disk->total = blk_mig_bytes_total();
438 get_xbzrle_cache_stats(info);
440 case MIGRATION_STATUS_COMPLETED:
441 get_xbzrle_cache_stats(info);
443 info->has_status = true;
444 info->has_total_time = true;
445 info->total_time = s->total_time;
446 info->has_downtime = true;
447 info->downtime = s->downtime;
448 info->has_setup_time = true;
449 info->setup_time = s->setup_time;
451 info->has_ram = true;
452 info->ram = g_malloc0(sizeof(*info->ram));
453 info->ram->transferred = ram_bytes_transferred();
454 info->ram->remaining = 0;
455 info->ram->total = ram_bytes_total();
456 info->ram->duplicate = dup_mig_pages_transferred();
457 info->ram->skipped = skipped_mig_pages_transferred();
458 info->ram->normal = norm_mig_pages_transferred();
459 info->ram->normal_bytes = norm_mig_bytes_transferred();
460 info->ram->mbps = s->mbps;
461 info->ram->dirty_sync_count = s->dirty_sync_count;
463 case MIGRATION_STATUS_FAILED:
464 info->has_status = true;
466 case MIGRATION_STATUS_CANCELLED:
467 info->has_status = true;
470 info->status = s->state;
475 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
478 MigrationState *s = migrate_get_current();
479 MigrationCapabilityStatusList *cap;
481 if (s->state == MIGRATION_STATUS_ACTIVE ||
482 s->state == MIGRATION_STATUS_SETUP) {
483 error_setg(errp, QERR_MIGRATION_ACTIVE);
487 for (cap = params; cap; cap = cap->next) {
488 s->enabled_capabilities[cap->value->capability] = cap->value->state;
492 void qmp_migrate_set_parameters(bool has_compress_level,
493 int64_t compress_level,
494 bool has_compress_threads,
495 int64_t compress_threads,
496 bool has_decompress_threads,
497 int64_t decompress_threads, Error **errp)
499 MigrationState *s = migrate_get_current();
501 if (has_compress_level && (compress_level < 0 || compress_level > 9)) {
502 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
503 "is invalid, it should be in the range of 0 to 9");
506 if (has_compress_threads &&
507 (compress_threads < 1 || compress_threads > 255)) {
508 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
510 "is invalid, it should be in the range of 1 to 255");
513 if (has_decompress_threads &&
514 (decompress_threads < 1 || decompress_threads > 255)) {
515 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
516 "decompress_threads",
517 "is invalid, it should be in the range of 1 to 255");
521 if (has_compress_level) {
522 s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
524 if (has_compress_threads) {
525 s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads;
527 if (has_decompress_threads) {
528 s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
533 /* shared migration helpers */
535 static void migrate_set_state(MigrationState *s, int old_state, int new_state)
537 if (atomic_cmpxchg(&s->state, old_state, new_state) == old_state) {
538 trace_migrate_set_state(new_state);
539 migrate_generate_event(new_state);
543 static void migrate_fd_cleanup(void *opaque)
545 MigrationState *s = opaque;
547 qemu_bh_delete(s->cleanup_bh);
548 s->cleanup_bh = NULL;
551 trace_migrate_fd_cleanup();
552 qemu_mutex_unlock_iothread();
553 qemu_thread_join(&s->thread);
554 qemu_mutex_lock_iothread();
556 migrate_compress_threads_join();
557 qemu_fclose(s->file);
561 assert(s->state != MIGRATION_STATUS_ACTIVE);
563 if (s->state != MIGRATION_STATUS_COMPLETED) {
564 qemu_savevm_state_cancel();
565 if (s->state == MIGRATION_STATUS_CANCELLING) {
566 migrate_set_state(s, MIGRATION_STATUS_CANCELLING,
567 MIGRATION_STATUS_CANCELLED);
571 notifier_list_notify(&migration_state_notifiers, s);
574 void migrate_fd_error(MigrationState *s)
576 trace_migrate_fd_error();
577 assert(s->file == NULL);
578 migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
579 notifier_list_notify(&migration_state_notifiers, s);
582 static void migrate_fd_cancel(MigrationState *s)
585 QEMUFile *f = migrate_get_current()->file;
586 trace_migrate_fd_cancel();
589 old_state = s->state;
590 if (old_state != MIGRATION_STATUS_SETUP &&
591 old_state != MIGRATION_STATUS_ACTIVE) {
594 migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING);
595 } while (s->state != MIGRATION_STATUS_CANCELLING);
598 * If we're unlucky the migration code might be stuck somewhere in a
599 * send/write while the network has failed and is waiting to timeout;
600 * if we've got shutdown(2) available then we can force it to quit.
601 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
602 * called in a bh, so there is no race against this cancel.
604 if (s->state == MIGRATION_STATUS_CANCELLING && f) {
605 qemu_file_shutdown(f);
609 void add_migration_state_change_notifier(Notifier *notify)
611 notifier_list_add(&migration_state_notifiers, notify);
614 void remove_migration_state_change_notifier(Notifier *notify)
616 notifier_remove(notify);
619 bool migration_in_setup(MigrationState *s)
621 return s->state == MIGRATION_STATUS_SETUP;
624 bool migration_has_finished(MigrationState *s)
626 return s->state == MIGRATION_STATUS_COMPLETED;
629 bool migration_has_failed(MigrationState *s)
631 return (s->state == MIGRATION_STATUS_CANCELLED ||
632 s->state == MIGRATION_STATUS_FAILED);
635 static MigrationState *migrate_init(const MigrationParams *params)
637 MigrationState *s = migrate_get_current();
638 int64_t bandwidth_limit = s->bandwidth_limit;
639 bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
640 int64_t xbzrle_cache_size = s->xbzrle_cache_size;
641 int compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
642 int compress_thread_count =
643 s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
644 int decompress_thread_count =
645 s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
647 memcpy(enabled_capabilities, s->enabled_capabilities,
648 sizeof(enabled_capabilities));
650 memset(s, 0, sizeof(*s));
652 memcpy(s->enabled_capabilities, enabled_capabilities,
653 sizeof(enabled_capabilities));
654 s->xbzrle_cache_size = xbzrle_cache_size;
656 s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
657 s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
658 compress_thread_count;
659 s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
660 decompress_thread_count;
661 s->bandwidth_limit = bandwidth_limit;
662 migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
664 s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
668 static GSList *migration_blockers;
670 void migrate_add_blocker(Error *reason)
672 migration_blockers = g_slist_prepend(migration_blockers, reason);
675 void migrate_del_blocker(Error *reason)
677 migration_blockers = g_slist_remove(migration_blockers, reason);
680 void qmp_migrate_incoming(const char *uri, Error **errp)
682 Error *local_err = NULL;
683 static bool once = true;
685 if (!deferred_incoming) {
686 error_setg(errp, "For use with '-incoming defer'");
690 error_setg(errp, "The incoming migration has already been started");
693 qemu_start_incoming_migration(uri, &local_err);
696 error_propagate(errp, local_err);
703 void qmp_migrate(const char *uri, bool has_blk, bool blk,
704 bool has_inc, bool inc, bool has_detach, bool detach,
707 Error *local_err = NULL;
708 MigrationState *s = migrate_get_current();
709 MigrationParams params;
712 params.blk = has_blk && blk;
713 params.shared = has_inc && inc;
715 if (s->state == MIGRATION_STATUS_ACTIVE ||
716 s->state == MIGRATION_STATUS_SETUP ||
717 s->state == MIGRATION_STATUS_CANCELLING) {
718 error_setg(errp, QERR_MIGRATION_ACTIVE);
721 if (runstate_check(RUN_STATE_INMIGRATE)) {
722 error_setg(errp, "Guest is waiting for an incoming migration");
726 if (qemu_savevm_state_blocked(errp)) {
730 if (migration_blockers) {
731 *errp = error_copy(migration_blockers->data);
735 /* We are starting a new migration, so we want to start in a clean
736 state. This change is only needed if previous migration
737 failed/was cancelled. We don't use migrate_set_state() because
738 we are setting the initial state, not changing it. */
739 s->state = MIGRATION_STATUS_NONE;
741 s = migrate_init(¶ms);
743 if (strstart(uri, "tcp:", &p)) {
744 tcp_start_outgoing_migration(s, p, &local_err);
746 } else if (strstart(uri, "rdma:", &p)) {
747 rdma_start_outgoing_migration(s, p, &local_err);
750 } else if (strstart(uri, "exec:", &p)) {
751 exec_start_outgoing_migration(s, p, &local_err);
752 } else if (strstart(uri, "unix:", &p)) {
753 unix_start_outgoing_migration(s, p, &local_err);
754 } else if (strstart(uri, "fd:", &p)) {
755 fd_start_outgoing_migration(s, p, &local_err);
758 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
759 "a valid migration protocol");
760 migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
766 error_propagate(errp, local_err);
771 void qmp_migrate_cancel(Error **errp)
773 migrate_fd_cancel(migrate_get_current());
776 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
778 MigrationState *s = migrate_get_current();
781 /* Check for truncation */
782 if (value != (size_t)value) {
783 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
784 "exceeding address space");
788 /* Cache should not be larger than guest ram size */
789 if (value > ram_bytes_total()) {
790 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
791 "exceeds guest ram size ");
795 new_size = xbzrle_cache_resize(value);
797 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
798 "is smaller than page size");
802 s->xbzrle_cache_size = new_size;
805 int64_t qmp_query_migrate_cache_size(Error **errp)
807 return migrate_xbzrle_cache_size();
810 void qmp_migrate_set_speed(int64_t value, Error **errp)
817 if (value > SIZE_MAX) {
821 s = migrate_get_current();
822 s->bandwidth_limit = value;
824 qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO);
828 void qmp_migrate_set_downtime(double value, Error **errp)
831 value = MAX(0, MIN(UINT64_MAX, value));
832 max_downtime = (uint64_t)value;
835 bool migrate_auto_converge(void)
839 s = migrate_get_current();
841 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
844 bool migrate_zero_blocks(void)
848 s = migrate_get_current();
850 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
853 bool migrate_use_compression(void)
857 s = migrate_get_current();
859 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
862 int migrate_compress_level(void)
866 s = migrate_get_current();
868 return s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
871 int migrate_compress_threads(void)
875 s = migrate_get_current();
877 return s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
880 int migrate_decompress_threads(void)
884 s = migrate_get_current();
886 return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
889 bool migrate_use_events(void)
893 s = migrate_get_current();
895 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
898 int migrate_use_xbzrle(void)
902 s = migrate_get_current();
904 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
907 int64_t migrate_xbzrle_cache_size(void)
911 s = migrate_get_current();
913 return s->xbzrle_cache_size;
916 /* migration thread support */
918 static void *migration_thread(void *opaque)
920 MigrationState *s = opaque;
921 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
922 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
923 int64_t initial_bytes = 0;
924 int64_t max_size = 0;
925 int64_t start_time = initial_time;
926 bool old_vm_running = false;
928 rcu_register_thread();
930 qemu_savevm_state_header(s->file);
931 qemu_savevm_state_begin(s->file, &s->params);
933 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
934 migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE);
936 while (s->state == MIGRATION_STATUS_ACTIVE) {
937 int64_t current_time;
938 uint64_t pending_size;
940 if (!qemu_file_rate_limit(s->file)) {
941 pending_size = qemu_savevm_state_pending(s->file, max_size);
942 trace_migrate_pending(pending_size, max_size);
943 if (pending_size && pending_size >= max_size) {
944 qemu_savevm_state_iterate(s->file);
948 qemu_mutex_lock_iothread();
949 start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
950 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
951 old_vm_running = runstate_is_running();
953 ret = global_state_store();
955 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
957 qemu_file_set_rate_limit(s->file, INT64_MAX);
958 qemu_savevm_state_complete(s->file);
961 qemu_mutex_unlock_iothread();
964 migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
965 MIGRATION_STATUS_FAILED);
969 if (!qemu_file_get_error(s->file)) {
970 migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
971 MIGRATION_STATUS_COMPLETED);
977 if (qemu_file_get_error(s->file)) {
978 migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
979 MIGRATION_STATUS_FAILED);
982 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
983 if (current_time >= initial_time + BUFFER_DELAY) {
984 uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;
985 uint64_t time_spent = current_time - initial_time;
986 double bandwidth = transferred_bytes / time_spent;
987 max_size = bandwidth * migrate_max_downtime() / 1000000;
989 s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
990 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
992 trace_migrate_transferred(transferred_bytes, time_spent,
993 bandwidth, max_size);
994 /* if we haven't sent anything, we don't want to recalculate
995 10000 is a small enough number for our purposes */
996 if (s->dirty_bytes_rate && transferred_bytes > 10000) {
997 s->expected_downtime = s->dirty_bytes_rate / bandwidth;
1000 qemu_file_reset_rate_limit(s->file);
1001 initial_time = current_time;
1002 initial_bytes = qemu_ftell(s->file);
1004 if (qemu_file_rate_limit(s->file)) {
1005 /* usleep expects microseconds */
1006 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
1010 qemu_mutex_lock_iothread();
1011 if (s->state == MIGRATION_STATUS_COMPLETED) {
1012 int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1013 uint64_t transferred_bytes = qemu_ftell(s->file);
1014 s->total_time = end_time - s->total_time;
1015 s->downtime = end_time - start_time;
1016 if (s->total_time) {
1017 s->mbps = (((double) transferred_bytes * 8.0) /
1018 ((double) s->total_time)) / 1000;
1020 runstate_set(RUN_STATE_POSTMIGRATE);
1022 if (old_vm_running) {
1026 qemu_bh_schedule(s->cleanup_bh);
1027 qemu_mutex_unlock_iothread();
1029 rcu_unregister_thread();
1033 void migrate_fd_connect(MigrationState *s)
1035 /* This is a best 1st approximation. ns to ms */
1036 s->expected_downtime = max_downtime/1000000;
1037 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
1039 qemu_file_set_rate_limit(s->file,
1040 s->bandwidth_limit / XFER_LIMIT_RATIO);
1042 /* Notify before starting migration thread */
1043 notifier_list_notify(&migration_state_notifiers, s);
1045 migrate_compress_threads_create();
1046 qemu_thread_create(&s->thread, "migration", migration_thread, s,
1047 QEMU_THREAD_JOINABLE);