block/parallels: add backing support to readv/writev
[qemu/ar7.git] / migration / migration.c
blobd3a1c494c0b5083bd43312d58456652f83a49e67
1 /*
2 * QEMU live migration
4 * Copyright IBM, Corp. 2008
6 * Authors:
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/osdep.h"
17 #include "qemu/cutils.h"
18 #include "qemu/error-report.h"
19 #include "migration/blocker.h"
20 #include "exec.h"
21 #include "fd.h"
22 #include "socket.h"
23 #include "rdma.h"
24 #include "ram.h"
25 #include "migration/global_state.h"
26 #include "migration/misc.h"
27 #include "migration.h"
28 #include "savevm.h"
29 #include "qemu-file-channel.h"
30 #include "qemu-file.h"
31 #include "migration/vmstate.h"
32 #include "block/block.h"
33 #include "qapi/qmp/qerror.h"
34 #include "qemu/rcu.h"
35 #include "block.h"
36 #include "postcopy-ram.h"
37 #include "qemu/thread.h"
38 #include "qmp-commands.h"
39 #include "trace.h"
40 #include "qapi-event.h"
41 #include "exec/target_page.h"
42 #include "io/channel-buffer.h"
43 #include "migration/colo.h"
44 #include "hw/boards.h"
45 #include "monitor/monitor.h"
47 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
49 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
50 * data. */
51 #define BUFFER_DELAY 100
52 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
54 /* Time in milliseconds we are allowed to stop the source,
55 * for sending the last part */
56 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
58 /* Maximum migrate downtime set to 2000 seconds */
59 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000
60 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000)
62 /* Default compression thread count */
63 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
64 /* Default decompression thread count, usually decompression is at
65 * least 4 times as fast as compression.*/
66 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
67 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
68 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
69 /* Define default autoconverge cpu throttle migration parameters */
70 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
71 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
73 /* Migration XBZRLE default cache size */
74 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024)
76 /* The delay time (in ms) between two COLO checkpoints
77 * Note: Please change this default value to 10000 when we support hybrid mode.
79 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200
80 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
81 #define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16
83 static NotifierList migration_state_notifiers =
84 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
86 static bool deferred_incoming;
88 /* Messages sent on the return path from destination to source */
89 enum mig_rp_message_type {
90 MIG_RP_MSG_INVALID = 0, /* Must be 0 */
91 MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */
92 MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */
94 MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
95 MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */
97 MIG_RP_MSG_MAX
100 /* When we add fault tolerance, we could have several
101 migrations at once. For now we don't need to add
102 dynamic creation of migration */
104 static MigrationState *current_migration;
106 static bool migration_object_check(MigrationState *ms, Error **errp);
107 static int migration_maybe_pause(MigrationState *s,
108 int *current_active_state,
109 int new_state);
111 void migration_object_init(void)
113 MachineState *ms = MACHINE(qdev_get_machine());
114 Error *err = NULL;
116 /* This can only be called once. */
117 assert(!current_migration);
118 current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
120 if (!migration_object_check(current_migration, &err)) {
121 error_report_err(err);
122 exit(1);
126 * We cannot really do this in migration_instance_init() since at
127 * that time global properties are not yet applied, then this
128 * value will be definitely replaced by something else.
130 if (ms->enforce_config_section) {
131 current_migration->send_configuration = true;
135 void migration_object_finalize(void)
137 object_unref(OBJECT(current_migration));
140 /* For outgoing */
141 MigrationState *migrate_get_current(void)
143 /* This can only be called after the object created. */
144 assert(current_migration);
145 return current_migration;
148 MigrationIncomingState *migration_incoming_get_current(void)
150 static bool once;
151 static MigrationIncomingState mis_current;
153 if (!once) {
154 mis_current.state = MIGRATION_STATUS_NONE;
155 memset(&mis_current, 0, sizeof(MigrationIncomingState));
156 qemu_mutex_init(&mis_current.rp_mutex);
157 qemu_event_init(&mis_current.main_thread_load_event, false);
158 once = true;
160 return &mis_current;
163 void migration_incoming_state_destroy(void)
165 struct MigrationIncomingState *mis = migration_incoming_get_current();
167 if (mis->to_src_file) {
168 /* Tell source that we are done */
169 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
170 qemu_fclose(mis->to_src_file);
171 mis->to_src_file = NULL;
174 if (mis->from_src_file) {
175 qemu_fclose(mis->from_src_file);
176 mis->from_src_file = NULL;
179 qemu_event_reset(&mis->main_thread_load_event);
182 static void migrate_generate_event(int new_state)
184 if (migrate_use_events()) {
185 qapi_event_send_migration(new_state, &error_abort);
190 * Called on -incoming with a defer: uri.
191 * The migration can be started later after any parameters have been
192 * changed.
194 static void deferred_incoming_migration(Error **errp)
196 if (deferred_incoming) {
197 error_setg(errp, "Incoming migration already deferred");
199 deferred_incoming = true;
203 * Send a message on the return channel back to the source
204 * of the migration.
206 static void migrate_send_rp_message(MigrationIncomingState *mis,
207 enum mig_rp_message_type message_type,
208 uint16_t len, void *data)
210 trace_migrate_send_rp_message((int)message_type, len);
211 qemu_mutex_lock(&mis->rp_mutex);
212 qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
213 qemu_put_be16(mis->to_src_file, len);
214 qemu_put_buffer(mis->to_src_file, data, len);
215 qemu_fflush(mis->to_src_file);
216 qemu_mutex_unlock(&mis->rp_mutex);
219 /* Request a range of pages from the source VM at the given
220 * start address.
221 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
222 * as the last request (a name must have been given previously)
223 * Start: Address offset within the RB
224 * Len: Length in bytes required - must be a multiple of pagesize
226 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
227 ram_addr_t start, size_t len)
229 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
230 size_t msglen = 12; /* start + len */
232 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
233 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
235 if (rbname) {
236 int rbname_len = strlen(rbname);
237 assert(rbname_len < 256);
239 bufc[msglen++] = rbname_len;
240 memcpy(bufc + msglen, rbname, rbname_len);
241 msglen += rbname_len;
242 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc);
243 } else {
244 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc);
248 void qemu_start_incoming_migration(const char *uri, Error **errp)
250 const char *p;
252 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort);
253 if (!strcmp(uri, "defer")) {
254 deferred_incoming_migration(errp);
255 } else if (strstart(uri, "tcp:", &p)) {
256 tcp_start_incoming_migration(p, errp);
257 #ifdef CONFIG_RDMA
258 } else if (strstart(uri, "rdma:", &p)) {
259 rdma_start_incoming_migration(p, errp);
260 #endif
261 } else if (strstart(uri, "exec:", &p)) {
262 exec_start_incoming_migration(p, errp);
263 } else if (strstart(uri, "unix:", &p)) {
264 unix_start_incoming_migration(p, errp);
265 } else if (strstart(uri, "fd:", &p)) {
266 fd_start_incoming_migration(p, errp);
267 } else {
268 error_setg(errp, "unknown migration protocol: %s", uri);
272 static void process_incoming_migration_bh(void *opaque)
274 Error *local_err = NULL;
275 MigrationIncomingState *mis = opaque;
277 /* Make sure all file formats flush their mutable metadata.
278 * If we get an error here, just don't restart the VM yet. */
279 bdrv_invalidate_cache_all(&local_err);
280 if (local_err) {
281 error_report_err(local_err);
282 local_err = NULL;
283 autostart = false;
287 * This must happen after all error conditions are dealt with and
288 * we're sure the VM is going to be running on this host.
290 qemu_announce_self();
292 if (multifd_load_cleanup(&local_err) != 0) {
293 error_report_err(local_err);
294 autostart = false;
296 /* If global state section was not received or we are in running
297 state, we need to obey autostart. Any other state is set with
298 runstate_set. */
300 if (!global_state_received() ||
301 global_state_get_runstate() == RUN_STATE_RUNNING) {
302 if (autostart) {
303 vm_start();
304 } else {
305 runstate_set(RUN_STATE_PAUSED);
307 } else {
308 runstate_set(global_state_get_runstate());
311 * This must happen after any state changes since as soon as an external
312 * observer sees this event they might start to prod at the VM assuming
313 * it's ready to use.
315 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
316 MIGRATION_STATUS_COMPLETED);
317 qemu_bh_delete(mis->bh);
318 migration_incoming_state_destroy();
321 static void process_incoming_migration_co(void *opaque)
323 MigrationIncomingState *mis = migration_incoming_get_current();
324 PostcopyState ps;
325 int ret;
327 assert(mis->from_src_file);
328 mis->largest_page_size = qemu_ram_pagesize_largest();
329 postcopy_state_set(POSTCOPY_INCOMING_NONE);
330 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
331 MIGRATION_STATUS_ACTIVE);
332 ret = qemu_loadvm_state(mis->from_src_file);
334 ps = postcopy_state_get();
335 trace_process_incoming_migration_co_end(ret, ps);
336 if (ps != POSTCOPY_INCOMING_NONE) {
337 if (ps == POSTCOPY_INCOMING_ADVISE) {
339 * Where a migration had postcopy enabled (and thus went to advise)
340 * but managed to complete within the precopy period, we can use
341 * the normal exit.
343 postcopy_ram_incoming_cleanup(mis);
344 } else if (ret >= 0) {
346 * Postcopy was started, cleanup should happen at the end of the
347 * postcopy thread.
349 trace_process_incoming_migration_co_postcopy_end_main();
350 return;
352 /* Else if something went wrong then just fall out of the normal exit */
355 /* we get COLO info, and know if we are in COLO mode */
356 if (!ret && migration_incoming_enable_colo()) {
357 mis->migration_incoming_co = qemu_coroutine_self();
358 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming",
359 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
360 mis->have_colo_incoming_thread = true;
361 qemu_coroutine_yield();
363 /* Wait checkpoint incoming thread exit before free resource */
364 qemu_thread_join(&mis->colo_incoming_thread);
367 if (ret < 0) {
368 Error *local_err = NULL;
370 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
371 MIGRATION_STATUS_FAILED);
372 error_report("load of migration failed: %s", strerror(-ret));
373 qemu_fclose(mis->from_src_file);
374 if (multifd_load_cleanup(&local_err) != 0) {
375 error_report_err(local_err);
377 exit(EXIT_FAILURE);
379 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
380 qemu_bh_schedule(mis->bh);
383 static void migration_incoming_setup(QEMUFile *f)
385 MigrationIncomingState *mis = migration_incoming_get_current();
387 if (multifd_load_setup() != 0) {
388 /* We haven't been able to create multifd threads
389 nothing better to do */
390 exit(EXIT_FAILURE);
393 if (!mis->from_src_file) {
394 mis->from_src_file = f;
396 qemu_file_set_blocking(f, false);
399 static void migration_incoming_process(void)
401 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
402 qemu_coroutine_enter(co);
405 void migration_fd_process_incoming(QEMUFile *f)
407 migration_incoming_setup(f);
408 migration_incoming_process();
411 void migration_ioc_process_incoming(QIOChannel *ioc)
413 MigrationIncomingState *mis = migration_incoming_get_current();
415 if (!mis->from_src_file) {
416 QEMUFile *f = qemu_fopen_channel_input(ioc);
417 migration_fd_process_incoming(f);
419 /* We still only have a single channel. Nothing to do here yet */
423 * @migration_has_all_channels: We have received all channels that we need
425 * Returns true when we have got connections to all the channels that
426 * we need for migration.
428 bool migration_has_all_channels(void)
430 return true;
434 * Send a 'SHUT' message on the return channel with the given value
435 * to indicate that we've finished with the RP. Non-0 value indicates
436 * error.
438 void migrate_send_rp_shut(MigrationIncomingState *mis,
439 uint32_t value)
441 uint32_t buf;
443 buf = cpu_to_be32(value);
444 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
448 * Send a 'PONG' message on the return channel with the given value
449 * (normally in response to a 'PING')
451 void migrate_send_rp_pong(MigrationIncomingState *mis,
452 uint32_t value)
454 uint32_t buf;
456 buf = cpu_to_be32(value);
457 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
460 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
462 MigrationCapabilityStatusList *head = NULL;
463 MigrationCapabilityStatusList *caps;
464 MigrationState *s = migrate_get_current();
465 int i;
467 caps = NULL; /* silence compiler warning */
468 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
469 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
470 if (i == MIGRATION_CAPABILITY_BLOCK) {
471 continue;
473 #endif
474 if (head == NULL) {
475 head = g_malloc0(sizeof(*caps));
476 caps = head;
477 } else {
478 caps->next = g_malloc0(sizeof(*caps));
479 caps = caps->next;
481 caps->value =
482 g_malloc(sizeof(*caps->value));
483 caps->value->capability = i;
484 caps->value->state = s->enabled_capabilities[i];
487 return head;
490 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
492 MigrationParameters *params;
493 MigrationState *s = migrate_get_current();
495 /* TODO use QAPI_CLONE() instead of duplicating it inline */
496 params = g_malloc0(sizeof(*params));
497 params->has_compress_level = true;
498 params->compress_level = s->parameters.compress_level;
499 params->has_compress_threads = true;
500 params->compress_threads = s->parameters.compress_threads;
501 params->has_decompress_threads = true;
502 params->decompress_threads = s->parameters.decompress_threads;
503 params->has_cpu_throttle_initial = true;
504 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial;
505 params->has_cpu_throttle_increment = true;
506 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment;
507 params->has_tls_creds = true;
508 params->tls_creds = g_strdup(s->parameters.tls_creds);
509 params->has_tls_hostname = true;
510 params->tls_hostname = g_strdup(s->parameters.tls_hostname);
511 params->has_max_bandwidth = true;
512 params->max_bandwidth = s->parameters.max_bandwidth;
513 params->has_downtime_limit = true;
514 params->downtime_limit = s->parameters.downtime_limit;
515 params->has_x_checkpoint_delay = true;
516 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay;
517 params->has_block_incremental = true;
518 params->block_incremental = s->parameters.block_incremental;
519 params->has_x_multifd_channels = true;
520 params->x_multifd_channels = s->parameters.x_multifd_channels;
521 params->has_x_multifd_page_count = true;
522 params->x_multifd_page_count = s->parameters.x_multifd_page_count;
523 params->has_xbzrle_cache_size = true;
524 params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
526 return params;
530 * Return true if we're already in the middle of a migration
531 * (i.e. any of the active or setup states)
533 static bool migration_is_setup_or_active(int state)
535 switch (state) {
536 case MIGRATION_STATUS_ACTIVE:
537 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
538 case MIGRATION_STATUS_SETUP:
539 case MIGRATION_STATUS_PRE_SWITCHOVER:
540 case MIGRATION_STATUS_DEVICE:
541 return true;
543 default:
544 return false;
549 static void populate_ram_info(MigrationInfo *info, MigrationState *s)
551 info->has_ram = true;
552 info->ram = g_malloc0(sizeof(*info->ram));
553 info->ram->transferred = ram_counters.transferred;
554 info->ram->total = ram_bytes_total();
555 info->ram->duplicate = ram_counters.duplicate;
556 /* legacy value. It is not used anymore */
557 info->ram->skipped = 0;
558 info->ram->normal = ram_counters.normal;
559 info->ram->normal_bytes = ram_counters.normal *
560 qemu_target_page_size();
561 info->ram->mbps = s->mbps;
562 info->ram->dirty_sync_count = ram_counters.dirty_sync_count;
563 info->ram->postcopy_requests = ram_counters.postcopy_requests;
564 info->ram->page_size = qemu_target_page_size();
566 if (migrate_use_xbzrle()) {
567 info->has_xbzrle_cache = true;
568 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
569 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
570 info->xbzrle_cache->bytes = xbzrle_counters.bytes;
571 info->xbzrle_cache->pages = xbzrle_counters.pages;
572 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss;
573 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate;
574 info->xbzrle_cache->overflow = xbzrle_counters.overflow;
577 if (cpu_throttle_active()) {
578 info->has_cpu_throttle_percentage = true;
579 info->cpu_throttle_percentage = cpu_throttle_get_percentage();
582 if (s->state != MIGRATION_STATUS_COMPLETED) {
583 info->ram->remaining = ram_bytes_remaining();
584 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate;
588 static void populate_disk_info(MigrationInfo *info)
590 if (blk_mig_active()) {
591 info->has_disk = true;
592 info->disk = g_malloc0(sizeof(*info->disk));
593 info->disk->transferred = blk_mig_bytes_transferred();
594 info->disk->remaining = blk_mig_bytes_remaining();
595 info->disk->total = blk_mig_bytes_total();
599 static void fill_source_migration_info(MigrationInfo *info)
601 MigrationState *s = migrate_get_current();
603 switch (s->state) {
604 case MIGRATION_STATUS_NONE:
605 /* no migration has happened ever */
606 /* do not overwrite destination migration status */
607 return;
608 break;
609 case MIGRATION_STATUS_SETUP:
610 info->has_status = true;
611 info->has_total_time = false;
612 break;
613 case MIGRATION_STATUS_ACTIVE:
614 case MIGRATION_STATUS_CANCELLING:
615 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
616 case MIGRATION_STATUS_PRE_SWITCHOVER:
617 case MIGRATION_STATUS_DEVICE:
618 /* TODO add some postcopy stats */
619 info->has_status = true;
620 info->has_total_time = true;
621 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
622 - s->start_time;
623 info->has_expected_downtime = true;
624 info->expected_downtime = s->expected_downtime;
625 info->has_setup_time = true;
626 info->setup_time = s->setup_time;
628 populate_ram_info(info, s);
629 populate_disk_info(info);
630 break;
631 case MIGRATION_STATUS_COLO:
632 info->has_status = true;
633 /* TODO: display COLO specific information (checkpoint info etc.) */
634 break;
635 case MIGRATION_STATUS_COMPLETED:
636 info->has_status = true;
637 info->has_total_time = true;
638 info->total_time = s->total_time;
639 info->has_downtime = true;
640 info->downtime = s->downtime;
641 info->has_setup_time = true;
642 info->setup_time = s->setup_time;
644 populate_ram_info(info, s);
645 break;
646 case MIGRATION_STATUS_FAILED:
647 info->has_status = true;
648 if (s->error) {
649 info->has_error_desc = true;
650 info->error_desc = g_strdup(error_get_pretty(s->error));
652 break;
653 case MIGRATION_STATUS_CANCELLED:
654 info->has_status = true;
655 break;
657 info->status = s->state;
661 * @migration_caps_check - check capability validity
663 * @cap_list: old capability list, array of bool
664 * @params: new capabilities to be applied soon
665 * @errp: set *errp if the check failed, with reason
667 * Returns true if check passed, otherwise false.
669 static bool migrate_caps_check(bool *cap_list,
670 MigrationCapabilityStatusList *params,
671 Error **errp)
673 MigrationCapabilityStatusList *cap;
674 bool old_postcopy_cap;
675 MigrationIncomingState *mis = migration_incoming_get_current();
677 old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM];
679 for (cap = params; cap; cap = cap->next) {
680 cap_list[cap->value->capability] = cap->value->state;
683 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
684 if (cap_list[MIGRATION_CAPABILITY_BLOCK]) {
685 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) "
686 "block migration");
687 error_append_hint(errp, "Use drive_mirror+NBD instead.\n");
688 return false;
690 #endif
692 if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) {
693 if (cap_list[MIGRATION_CAPABILITY_COMPRESS]) {
694 /* The decompression threads asynchronously write into RAM
695 * rather than use the atomic copies needed to avoid
696 * userfaulting. It should be possible to fix the decompression
697 * threads for compatibility in future.
699 error_setg(errp, "Postcopy is not currently compatible "
700 "with compression");
701 return false;
704 /* This check is reasonably expensive, so only when it's being
705 * set the first time, also it's only the destination that needs
706 * special support.
708 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) &&
709 !postcopy_ram_supported_by_host(mis)) {
710 /* postcopy_ram_supported_by_host will have emitted a more
711 * detailed message
713 error_setg(errp, "Postcopy is not supported");
714 return false;
718 return true;
721 static void fill_destination_migration_info(MigrationInfo *info)
723 MigrationIncomingState *mis = migration_incoming_get_current();
725 switch (mis->state) {
726 case MIGRATION_STATUS_NONE:
727 return;
728 break;
729 case MIGRATION_STATUS_SETUP:
730 case MIGRATION_STATUS_CANCELLING:
731 case MIGRATION_STATUS_CANCELLED:
732 case MIGRATION_STATUS_ACTIVE:
733 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
734 case MIGRATION_STATUS_FAILED:
735 case MIGRATION_STATUS_COLO:
736 info->has_status = true;
737 break;
738 case MIGRATION_STATUS_COMPLETED:
739 info->has_status = true;
740 fill_destination_postcopy_migration_info(info);
741 break;
743 info->status = mis->state;
746 MigrationInfo *qmp_query_migrate(Error **errp)
748 MigrationInfo *info = g_malloc0(sizeof(*info));
750 fill_destination_migration_info(info);
751 fill_source_migration_info(info);
753 return info;
756 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
757 Error **errp)
759 MigrationState *s = migrate_get_current();
760 MigrationCapabilityStatusList *cap;
762 if (migration_is_setup_or_active(s->state)) {
763 error_setg(errp, QERR_MIGRATION_ACTIVE);
764 return;
767 if (!migrate_caps_check(s->enabled_capabilities, params, errp)) {
768 return;
771 for (cap = params; cap; cap = cap->next) {
772 s->enabled_capabilities[cap->value->capability] = cap->value->state;
777 * Check whether the parameters are valid. Error will be put into errp
778 * (if provided). Return true if valid, otherwise false.
780 static bool migrate_params_check(MigrationParameters *params, Error **errp)
782 if (params->has_compress_level &&
783 (params->compress_level > 9)) {
784 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
785 "is invalid, it should be in the range of 0 to 9");
786 return false;
789 if (params->has_compress_threads && (params->compress_threads < 1)) {
790 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
791 "compress_threads",
792 "is invalid, it should be in the range of 1 to 255");
793 return false;
796 if (params->has_decompress_threads && (params->decompress_threads < 1)) {
797 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
798 "decompress_threads",
799 "is invalid, it should be in the range of 1 to 255");
800 return false;
803 if (params->has_cpu_throttle_initial &&
804 (params->cpu_throttle_initial < 1 ||
805 params->cpu_throttle_initial > 99)) {
806 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
807 "cpu_throttle_initial",
808 "an integer in the range of 1 to 99");
809 return false;
812 if (params->has_cpu_throttle_increment &&
813 (params->cpu_throttle_increment < 1 ||
814 params->cpu_throttle_increment > 99)) {
815 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
816 "cpu_throttle_increment",
817 "an integer in the range of 1 to 99");
818 return false;
821 if (params->has_max_bandwidth && (params->max_bandwidth > SIZE_MAX)) {
822 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the"
823 " range of 0 to %zu bytes/second", SIZE_MAX);
824 return false;
827 if (params->has_downtime_limit &&
828 (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) {
829 error_setg(errp, "Parameter 'downtime_limit' expects an integer in "
830 "the range of 0 to %d milliseconds",
831 MAX_MIGRATE_DOWNTIME);
832 return false;
835 /* x_checkpoint_delay is now always positive */
837 if (params->has_x_multifd_channels && (params->x_multifd_channels < 1)) {
838 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
839 "multifd_channels",
840 "is invalid, it should be in the range of 1 to 255");
841 return false;
843 if (params->has_x_multifd_page_count &&
844 (params->x_multifd_page_count < 1 ||
845 params->x_multifd_page_count > 10000)) {
846 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
847 "multifd_page_count",
848 "is invalid, it should be in the range of 1 to 10000");
849 return false;
852 if (params->has_xbzrle_cache_size &&
853 (params->xbzrle_cache_size < qemu_target_page_size() ||
854 !is_power_of_2(params->xbzrle_cache_size))) {
855 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
856 "xbzrle_cache_size",
857 "is invalid, it should be bigger than target page size"
858 " and a power of two");
859 return false;
862 return true;
865 static void migrate_params_test_apply(MigrateSetParameters *params,
866 MigrationParameters *dest)
868 *dest = migrate_get_current()->parameters;
870 /* TODO use QAPI_CLONE() instead of duplicating it inline */
872 if (params->has_compress_level) {
873 dest->compress_level = params->compress_level;
876 if (params->has_compress_threads) {
877 dest->compress_threads = params->compress_threads;
880 if (params->has_decompress_threads) {
881 dest->decompress_threads = params->decompress_threads;
884 if (params->has_cpu_throttle_initial) {
885 dest->cpu_throttle_initial = params->cpu_throttle_initial;
888 if (params->has_cpu_throttle_increment) {
889 dest->cpu_throttle_increment = params->cpu_throttle_increment;
892 if (params->has_tls_creds) {
893 assert(params->tls_creds->type == QTYPE_QSTRING);
894 dest->tls_creds = g_strdup(params->tls_creds->u.s);
897 if (params->has_tls_hostname) {
898 assert(params->tls_hostname->type == QTYPE_QSTRING);
899 dest->tls_hostname = g_strdup(params->tls_hostname->u.s);
902 if (params->has_max_bandwidth) {
903 dest->max_bandwidth = params->max_bandwidth;
906 if (params->has_downtime_limit) {
907 dest->downtime_limit = params->downtime_limit;
910 if (params->has_x_checkpoint_delay) {
911 dest->x_checkpoint_delay = params->x_checkpoint_delay;
914 if (params->has_block_incremental) {
915 dest->block_incremental = params->block_incremental;
917 if (params->has_x_multifd_channels) {
918 dest->x_multifd_channels = params->x_multifd_channels;
920 if (params->has_x_multifd_page_count) {
921 dest->x_multifd_page_count = params->x_multifd_page_count;
923 if (params->has_xbzrle_cache_size) {
924 dest->xbzrle_cache_size = params->xbzrle_cache_size;
928 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
930 MigrationState *s = migrate_get_current();
932 /* TODO use QAPI_CLONE() instead of duplicating it inline */
934 if (params->has_compress_level) {
935 s->parameters.compress_level = params->compress_level;
938 if (params->has_compress_threads) {
939 s->parameters.compress_threads = params->compress_threads;
942 if (params->has_decompress_threads) {
943 s->parameters.decompress_threads = params->decompress_threads;
946 if (params->has_cpu_throttle_initial) {
947 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial;
950 if (params->has_cpu_throttle_increment) {
951 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment;
954 if (params->has_tls_creds) {
955 g_free(s->parameters.tls_creds);
956 assert(params->tls_creds->type == QTYPE_QSTRING);
957 s->parameters.tls_creds = g_strdup(params->tls_creds->u.s);
960 if (params->has_tls_hostname) {
961 g_free(s->parameters.tls_hostname);
962 assert(params->tls_hostname->type == QTYPE_QSTRING);
963 s->parameters.tls_hostname = g_strdup(params->tls_hostname->u.s);
966 if (params->has_max_bandwidth) {
967 s->parameters.max_bandwidth = params->max_bandwidth;
968 if (s->to_dst_file) {
969 qemu_file_set_rate_limit(s->to_dst_file,
970 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
974 if (params->has_downtime_limit) {
975 s->parameters.downtime_limit = params->downtime_limit;
978 if (params->has_x_checkpoint_delay) {
979 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay;
980 if (migration_in_colo_state()) {
981 colo_checkpoint_notify(s);
985 if (params->has_block_incremental) {
986 s->parameters.block_incremental = params->block_incremental;
988 if (params->has_x_multifd_channels) {
989 s->parameters.x_multifd_channels = params->x_multifd_channels;
991 if (params->has_x_multifd_page_count) {
992 s->parameters.x_multifd_page_count = params->x_multifd_page_count;
994 if (params->has_xbzrle_cache_size) {
995 s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
996 xbzrle_cache_resize(params->xbzrle_cache_size, errp);
1000 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
1002 MigrationParameters tmp;
1004 /* TODO Rewrite "" to null instead */
1005 if (params->has_tls_creds
1006 && params->tls_creds->type == QTYPE_QNULL) {
1007 QDECREF(params->tls_creds->u.n);
1008 params->tls_creds->type = QTYPE_QSTRING;
1009 params->tls_creds->u.s = strdup("");
1011 /* TODO Rewrite "" to null instead */
1012 if (params->has_tls_hostname
1013 && params->tls_hostname->type == QTYPE_QNULL) {
1014 QDECREF(params->tls_hostname->u.n);
1015 params->tls_hostname->type = QTYPE_QSTRING;
1016 params->tls_hostname->u.s = strdup("");
1019 migrate_params_test_apply(params, &tmp);
1021 if (!migrate_params_check(&tmp, errp)) {
1022 /* Invalid parameter */
1023 return;
1026 migrate_params_apply(params, errp);
1030 void qmp_migrate_start_postcopy(Error **errp)
1032 MigrationState *s = migrate_get_current();
1034 if (!migrate_postcopy_ram()) {
1035 error_setg(errp, "Enable postcopy with migrate_set_capability before"
1036 " the start of migration");
1037 return;
1040 if (s->state == MIGRATION_STATUS_NONE) {
1041 error_setg(errp, "Postcopy must be started after migration has been"
1042 " started");
1043 return;
1046 * we don't error if migration has finished since that would be racy
1047 * with issuing this command.
1049 atomic_set(&s->start_postcopy, true);
1052 /* shared migration helpers */
1054 void migrate_set_state(int *state, int old_state, int new_state)
1056 assert(new_state < MIGRATION_STATUS__MAX);
1057 if (atomic_cmpxchg(state, old_state, new_state) == old_state) {
1058 trace_migrate_set_state(MigrationStatus_str(new_state));
1059 migrate_generate_event(new_state);
1063 static MigrationCapabilityStatusList *migrate_cap_add(
1064 MigrationCapabilityStatusList *list,
1065 MigrationCapability index,
1066 bool state)
1068 MigrationCapabilityStatusList *cap;
1070 cap = g_new0(MigrationCapabilityStatusList, 1);
1071 cap->value = g_new0(MigrationCapabilityStatus, 1);
1072 cap->value->capability = index;
1073 cap->value->state = state;
1074 cap->next = list;
1076 return cap;
1079 void migrate_set_block_enabled(bool value, Error **errp)
1081 MigrationCapabilityStatusList *cap;
1083 cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value);
1084 qmp_migrate_set_capabilities(cap, errp);
1085 qapi_free_MigrationCapabilityStatusList(cap);
1088 static void migrate_set_block_incremental(MigrationState *s, bool value)
1090 s->parameters.block_incremental = value;
1093 static void block_cleanup_parameters(MigrationState *s)
1095 if (s->must_remove_block_options) {
1096 /* setting to false can never fail */
1097 migrate_set_block_enabled(false, &error_abort);
1098 migrate_set_block_incremental(s, false);
1099 s->must_remove_block_options = false;
1103 static void migrate_fd_cleanup(void *opaque)
1105 MigrationState *s = opaque;
1107 qemu_bh_delete(s->cleanup_bh);
1108 s->cleanup_bh = NULL;
1110 qemu_savevm_state_cleanup();
1112 if (s->to_dst_file) {
1113 Error *local_err = NULL;
1115 trace_migrate_fd_cleanup();
1116 qemu_mutex_unlock_iothread();
1117 if (s->migration_thread_running) {
1118 qemu_thread_join(&s->thread);
1119 s->migration_thread_running = false;
1121 qemu_mutex_lock_iothread();
1123 if (multifd_save_cleanup(&local_err) != 0) {
1124 error_report_err(local_err);
1126 qemu_fclose(s->to_dst_file);
1127 s->to_dst_file = NULL;
1130 assert((s->state != MIGRATION_STATUS_ACTIVE) &&
1131 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE));
1133 if (s->state == MIGRATION_STATUS_CANCELLING) {
1134 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
1135 MIGRATION_STATUS_CANCELLED);
1138 if (s->error) {
1139 /* It is used on info migrate. We can't free it */
1140 error_report_err(error_copy(s->error));
1142 notifier_list_notify(&migration_state_notifiers, s);
1143 block_cleanup_parameters(s);
1146 void migrate_set_error(MigrationState *s, const Error *error)
1148 qemu_mutex_lock(&s->error_mutex);
1149 if (!s->error) {
1150 s->error = error_copy(error);
1152 qemu_mutex_unlock(&s->error_mutex);
1155 void migrate_fd_error(MigrationState *s, const Error *error)
1157 trace_migrate_fd_error(error_get_pretty(error));
1158 assert(s->to_dst_file == NULL);
1159 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1160 MIGRATION_STATUS_FAILED);
1161 migrate_set_error(s, error);
1164 static void migrate_fd_cancel(MigrationState *s)
1166 int old_state ;
1167 QEMUFile *f = migrate_get_current()->to_dst_file;
1168 trace_migrate_fd_cancel();
1170 if (s->rp_state.from_dst_file) {
1171 /* shutdown the rp socket, so causing the rp thread to shutdown */
1172 qemu_file_shutdown(s->rp_state.from_dst_file);
1175 do {
1176 old_state = s->state;
1177 if (!migration_is_setup_or_active(old_state)) {
1178 break;
1180 /* If the migration is paused, kick it out of the pause */
1181 if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) {
1182 qemu_sem_post(&s->pause_sem);
1184 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
1185 } while (s->state != MIGRATION_STATUS_CANCELLING);
1188 * If we're unlucky the migration code might be stuck somewhere in a
1189 * send/write while the network has failed and is waiting to timeout;
1190 * if we've got shutdown(2) available then we can force it to quit.
1191 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1192 * called in a bh, so there is no race against this cancel.
1194 if (s->state == MIGRATION_STATUS_CANCELLING && f) {
1195 qemu_file_shutdown(f);
1197 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
1198 Error *local_err = NULL;
1200 bdrv_invalidate_cache_all(&local_err);
1201 if (local_err) {
1202 error_report_err(local_err);
1203 } else {
1204 s->block_inactive = false;
1209 void add_migration_state_change_notifier(Notifier *notify)
1211 notifier_list_add(&migration_state_notifiers, notify);
1214 void remove_migration_state_change_notifier(Notifier *notify)
1216 notifier_remove(notify);
1219 bool migration_in_setup(MigrationState *s)
1221 return s->state == MIGRATION_STATUS_SETUP;
1224 bool migration_has_finished(MigrationState *s)
1226 return s->state == MIGRATION_STATUS_COMPLETED;
1229 bool migration_has_failed(MigrationState *s)
1231 return (s->state == MIGRATION_STATUS_CANCELLED ||
1232 s->state == MIGRATION_STATUS_FAILED);
1235 bool migration_in_postcopy(void)
1237 MigrationState *s = migrate_get_current();
1239 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
1242 bool migration_in_postcopy_after_devices(MigrationState *s)
1244 return migration_in_postcopy() && s->postcopy_after_devices;
1247 bool migration_is_idle(void)
1249 MigrationState *s = migrate_get_current();
1251 switch (s->state) {
1252 case MIGRATION_STATUS_NONE:
1253 case MIGRATION_STATUS_CANCELLED:
1254 case MIGRATION_STATUS_COMPLETED:
1255 case MIGRATION_STATUS_FAILED:
1256 return true;
1257 case MIGRATION_STATUS_SETUP:
1258 case MIGRATION_STATUS_CANCELLING:
1259 case MIGRATION_STATUS_ACTIVE:
1260 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1261 case MIGRATION_STATUS_COLO:
1262 case MIGRATION_STATUS_PRE_SWITCHOVER:
1263 case MIGRATION_STATUS_DEVICE:
1264 return false;
1265 case MIGRATION_STATUS__MAX:
1266 g_assert_not_reached();
1269 return false;
1272 MigrationState *migrate_init(void)
1274 MigrationState *s = migrate_get_current();
1277 * Reinitialise all migration state, except
1278 * parameters/capabilities that the user set, and
1279 * locks.
1281 s->bytes_xfer = 0;
1282 s->xfer_limit = 0;
1283 s->cleanup_bh = 0;
1284 s->to_dst_file = NULL;
1285 s->state = MIGRATION_STATUS_NONE;
1286 s->rp_state.from_dst_file = NULL;
1287 s->rp_state.error = false;
1288 s->mbps = 0.0;
1289 s->downtime = 0;
1290 s->expected_downtime = 0;
1291 s->setup_time = 0;
1292 s->start_postcopy = false;
1293 s->postcopy_after_devices = false;
1294 s->migration_thread_running = false;
1295 error_free(s->error);
1296 s->error = NULL;
1298 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
1300 s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1301 s->total_time = 0;
1302 s->vm_was_running = false;
1303 s->iteration_initial_bytes = 0;
1304 s->threshold_size = 0;
1305 return s;
1308 static GSList *migration_blockers;
1310 int migrate_add_blocker(Error *reason, Error **errp)
1312 if (migrate_get_current()->only_migratable) {
1313 error_propagate(errp, error_copy(reason));
1314 error_prepend(errp, "disallowing migration blocker "
1315 "(--only_migratable) for: ");
1316 return -EACCES;
1319 if (migration_is_idle()) {
1320 migration_blockers = g_slist_prepend(migration_blockers, reason);
1321 return 0;
1324 error_propagate(errp, error_copy(reason));
1325 error_prepend(errp, "disallowing migration blocker (migration in "
1326 "progress) for: ");
1327 return -EBUSY;
1330 void migrate_del_blocker(Error *reason)
1332 migration_blockers = g_slist_remove(migration_blockers, reason);
1335 void qmp_migrate_incoming(const char *uri, Error **errp)
1337 Error *local_err = NULL;
1338 static bool once = true;
1340 if (!deferred_incoming) {
1341 error_setg(errp, "For use with '-incoming defer'");
1342 return;
1344 if (!once) {
1345 error_setg(errp, "The incoming migration has already been started");
1348 qemu_start_incoming_migration(uri, &local_err);
1350 if (local_err) {
1351 error_propagate(errp, local_err);
1352 return;
1355 once = false;
1358 bool migration_is_blocked(Error **errp)
1360 if (qemu_savevm_state_blocked(errp)) {
1361 return true;
1364 if (migration_blockers) {
1365 error_propagate(errp, error_copy(migration_blockers->data));
1366 return true;
1369 return false;
1372 void qmp_migrate(const char *uri, bool has_blk, bool blk,
1373 bool has_inc, bool inc, bool has_detach, bool detach,
1374 Error **errp)
1376 Error *local_err = NULL;
1377 MigrationState *s = migrate_get_current();
1378 const char *p;
1380 if (migration_is_setup_or_active(s->state) ||
1381 s->state == MIGRATION_STATUS_CANCELLING ||
1382 s->state == MIGRATION_STATUS_COLO) {
1383 error_setg(errp, QERR_MIGRATION_ACTIVE);
1384 return;
1386 if (runstate_check(RUN_STATE_INMIGRATE)) {
1387 error_setg(errp, "Guest is waiting for an incoming migration");
1388 return;
1391 if (migration_is_blocked(errp)) {
1392 return;
1395 if ((has_blk && blk) || (has_inc && inc)) {
1396 if (migrate_use_block() || migrate_use_block_incremental()) {
1397 error_setg(errp, "Command options are incompatible with "
1398 "current migration capabilities");
1399 return;
1401 migrate_set_block_enabled(true, &local_err);
1402 if (local_err) {
1403 error_propagate(errp, local_err);
1404 return;
1406 s->must_remove_block_options = true;
1409 if (has_inc && inc) {
1410 migrate_set_block_incremental(s, true);
1413 s = migrate_init();
1415 if (strstart(uri, "tcp:", &p)) {
1416 tcp_start_outgoing_migration(s, p, &local_err);
1417 #ifdef CONFIG_RDMA
1418 } else if (strstart(uri, "rdma:", &p)) {
1419 rdma_start_outgoing_migration(s, p, &local_err);
1420 #endif
1421 } else if (strstart(uri, "exec:", &p)) {
1422 exec_start_outgoing_migration(s, p, &local_err);
1423 } else if (strstart(uri, "unix:", &p)) {
1424 unix_start_outgoing_migration(s, p, &local_err);
1425 } else if (strstart(uri, "fd:", &p)) {
1426 fd_start_outgoing_migration(s, p, &local_err);
1427 } else {
1428 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
1429 "a valid migration protocol");
1430 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1431 MIGRATION_STATUS_FAILED);
1432 return;
1435 if (local_err) {
1436 migrate_fd_error(s, local_err);
1437 error_propagate(errp, local_err);
1438 return;
1442 void qmp_migrate_cancel(Error **errp)
1444 migrate_fd_cancel(migrate_get_current());
1447 void qmp_migrate_continue(MigrationStatus state, Error **errp)
1449 MigrationState *s = migrate_get_current();
1450 if (s->state != state) {
1451 error_setg(errp, "Migration not in expected state: %s",
1452 MigrationStatus_str(s->state));
1453 return;
1455 qemu_sem_post(&s->pause_sem);
1458 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
1460 MigrateSetParameters p = {
1461 .has_xbzrle_cache_size = true,
1462 .xbzrle_cache_size = value,
1465 qmp_migrate_set_parameters(&p, errp);
1468 int64_t qmp_query_migrate_cache_size(Error **errp)
1470 return migrate_xbzrle_cache_size();
1473 void qmp_migrate_set_speed(int64_t value, Error **errp)
1475 MigrateSetParameters p = {
1476 .has_max_bandwidth = true,
1477 .max_bandwidth = value,
1480 qmp_migrate_set_parameters(&p, errp);
1483 void qmp_migrate_set_downtime(double value, Error **errp)
1485 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) {
1486 error_setg(errp, "Parameter 'downtime_limit' expects an integer in "
1487 "the range of 0 to %d seconds",
1488 MAX_MIGRATE_DOWNTIME_SECONDS);
1489 return;
1492 value *= 1000; /* Convert to milliseconds */
1493 value = MAX(0, MIN(INT64_MAX, value));
1495 MigrateSetParameters p = {
1496 .has_downtime_limit = true,
1497 .downtime_limit = value,
1500 qmp_migrate_set_parameters(&p, errp);
1503 bool migrate_release_ram(void)
1505 MigrationState *s;
1507 s = migrate_get_current();
1509 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM];
1512 bool migrate_postcopy_ram(void)
1514 MigrationState *s;
1516 s = migrate_get_current();
1518 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM];
1521 bool migrate_postcopy(void)
1523 return migrate_postcopy_ram();
1526 bool migrate_auto_converge(void)
1528 MigrationState *s;
1530 s = migrate_get_current();
1532 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
1535 bool migrate_zero_blocks(void)
1537 MigrationState *s;
1539 s = migrate_get_current();
1541 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
1544 bool migrate_postcopy_blocktime(void)
1546 MigrationState *s;
1548 s = migrate_get_current();
1550 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME];
1553 bool migrate_use_compression(void)
1555 MigrationState *s;
1557 s = migrate_get_current();
1559 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
1562 int migrate_compress_level(void)
1564 MigrationState *s;
1566 s = migrate_get_current();
1568 return s->parameters.compress_level;
1571 int migrate_compress_threads(void)
1573 MigrationState *s;
1575 s = migrate_get_current();
1577 return s->parameters.compress_threads;
1580 int migrate_decompress_threads(void)
1582 MigrationState *s;
1584 s = migrate_get_current();
1586 return s->parameters.decompress_threads;
1589 bool migrate_use_events(void)
1591 MigrationState *s;
1593 s = migrate_get_current();
1595 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
1598 bool migrate_use_multifd(void)
1600 MigrationState *s;
1602 s = migrate_get_current();
1604 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD];
1607 bool migrate_pause_before_switchover(void)
1609 MigrationState *s;
1611 s = migrate_get_current();
1613 return s->enabled_capabilities[
1614 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
1617 int migrate_multifd_channels(void)
1619 MigrationState *s;
1621 s = migrate_get_current();
1623 return s->parameters.x_multifd_channels;
1626 int migrate_multifd_page_count(void)
1628 MigrationState *s;
1630 s = migrate_get_current();
1632 return s->parameters.x_multifd_page_count;
1635 int migrate_use_xbzrle(void)
1637 MigrationState *s;
1639 s = migrate_get_current();
1641 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
1644 int64_t migrate_xbzrle_cache_size(void)
1646 MigrationState *s;
1648 s = migrate_get_current();
1650 return s->parameters.xbzrle_cache_size;
1653 bool migrate_use_block(void)
1655 MigrationState *s;
1657 s = migrate_get_current();
1659 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK];
1662 bool migrate_use_return_path(void)
1664 MigrationState *s;
1666 s = migrate_get_current();
1668 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH];
1671 bool migrate_use_block_incremental(void)
1673 MigrationState *s;
1675 s = migrate_get_current();
1677 return s->parameters.block_incremental;
1680 /* migration thread support */
1682 * Something bad happened to the RP stream, mark an error
1683 * The caller shall print or trace something to indicate why
1685 static void mark_source_rp_bad(MigrationState *s)
1687 s->rp_state.error = true;
1690 static struct rp_cmd_args {
1691 ssize_t len; /* -1 = variable */
1692 const char *name;
1693 } rp_cmd_args[] = {
1694 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
1695 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
1696 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
1697 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
1698 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
1699 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
1703 * Process a request for pages received on the return path,
1704 * We're allowed to send more than requested (e.g. to round to our page size)
1705 * and we don't need to send pages that have already been sent.
1707 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
1708 ram_addr_t start, size_t len)
1710 long our_host_ps = getpagesize();
1712 trace_migrate_handle_rp_req_pages(rbname, start, len);
1715 * Since we currently insist on matching page sizes, just sanity check
1716 * we're being asked for whole host pages.
1718 if (start & (our_host_ps-1) ||
1719 (len & (our_host_ps-1))) {
1720 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
1721 " len: %zd", __func__, start, len);
1722 mark_source_rp_bad(ms);
1723 return;
1726 if (ram_save_queue_pages(rbname, start, len)) {
1727 mark_source_rp_bad(ms);
1732 * Handles messages sent on the return path towards the source VM
1735 static void *source_return_path_thread(void *opaque)
1737 MigrationState *ms = opaque;
1738 QEMUFile *rp = ms->rp_state.from_dst_file;
1739 uint16_t header_len, header_type;
1740 uint8_t buf[512];
1741 uint32_t tmp32, sibling_error;
1742 ram_addr_t start = 0; /* =0 to silence warning */
1743 size_t len = 0, expected_len;
1744 int res;
1746 trace_source_return_path_thread_entry();
1747 while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
1748 migration_is_setup_or_active(ms->state)) {
1749 trace_source_return_path_thread_loop_top();
1750 header_type = qemu_get_be16(rp);
1751 header_len = qemu_get_be16(rp);
1753 if (header_type >= MIG_RP_MSG_MAX ||
1754 header_type == MIG_RP_MSG_INVALID) {
1755 error_report("RP: Received invalid message 0x%04x length 0x%04x",
1756 header_type, header_len);
1757 mark_source_rp_bad(ms);
1758 goto out;
1761 if ((rp_cmd_args[header_type].len != -1 &&
1762 header_len != rp_cmd_args[header_type].len) ||
1763 header_len > sizeof(buf)) {
1764 error_report("RP: Received '%s' message (0x%04x) with"
1765 "incorrect length %d expecting %zu",
1766 rp_cmd_args[header_type].name, header_type, header_len,
1767 (size_t)rp_cmd_args[header_type].len);
1768 mark_source_rp_bad(ms);
1769 goto out;
1772 /* We know we've got a valid header by this point */
1773 res = qemu_get_buffer(rp, buf, header_len);
1774 if (res != header_len) {
1775 error_report("RP: Failed reading data for message 0x%04x"
1776 " read %d expected %d",
1777 header_type, res, header_len);
1778 mark_source_rp_bad(ms);
1779 goto out;
1782 /* OK, we have the message and the data */
1783 switch (header_type) {
1784 case MIG_RP_MSG_SHUT:
1785 sibling_error = ldl_be_p(buf);
1786 trace_source_return_path_thread_shut(sibling_error);
1787 if (sibling_error) {
1788 error_report("RP: Sibling indicated error %d", sibling_error);
1789 mark_source_rp_bad(ms);
1792 * We'll let the main thread deal with closing the RP
1793 * we could do a shutdown(2) on it, but we're the only user
1794 * anyway, so there's nothing gained.
1796 goto out;
1798 case MIG_RP_MSG_PONG:
1799 tmp32 = ldl_be_p(buf);
1800 trace_source_return_path_thread_pong(tmp32);
1801 break;
1803 case MIG_RP_MSG_REQ_PAGES:
1804 start = ldq_be_p(buf);
1805 len = ldl_be_p(buf + 8);
1806 migrate_handle_rp_req_pages(ms, NULL, start, len);
1807 break;
1809 case MIG_RP_MSG_REQ_PAGES_ID:
1810 expected_len = 12 + 1; /* header + termination */
1812 if (header_len >= expected_len) {
1813 start = ldq_be_p(buf);
1814 len = ldl_be_p(buf + 8);
1815 /* Now we expect an idstr */
1816 tmp32 = buf[12]; /* Length of the following idstr */
1817 buf[13 + tmp32] = '\0';
1818 expected_len += tmp32;
1820 if (header_len != expected_len) {
1821 error_report("RP: Req_Page_id with length %d expecting %zd",
1822 header_len, expected_len);
1823 mark_source_rp_bad(ms);
1824 goto out;
1826 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
1827 break;
1829 default:
1830 break;
1833 if (qemu_file_get_error(rp)) {
1834 trace_source_return_path_thread_bad_end();
1835 mark_source_rp_bad(ms);
1838 trace_source_return_path_thread_end();
1839 out:
1840 ms->rp_state.from_dst_file = NULL;
1841 qemu_fclose(rp);
1842 return NULL;
1845 static int open_return_path_on_source(MigrationState *ms)
1848 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
1849 if (!ms->rp_state.from_dst_file) {
1850 return -1;
1853 trace_open_return_path_on_source();
1854 qemu_thread_create(&ms->rp_state.rp_thread, "return path",
1855 source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
1857 trace_open_return_path_on_source_continue();
1859 return 0;
1862 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1863 static int await_return_path_close_on_source(MigrationState *ms)
1866 * If this is a normal exit then the destination will send a SHUT and the
1867 * rp_thread will exit, however if there's an error we need to cause
1868 * it to exit.
1870 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) {
1872 * shutdown(2), if we have it, will cause it to unblock if it's stuck
1873 * waiting for the destination.
1875 qemu_file_shutdown(ms->rp_state.from_dst_file);
1876 mark_source_rp_bad(ms);
1878 trace_await_return_path_close_on_source_joining();
1879 qemu_thread_join(&ms->rp_state.rp_thread);
1880 trace_await_return_path_close_on_source_close();
1881 return ms->rp_state.error;
1885 * Switch from normal iteration to postcopy
1886 * Returns non-0 on error
1888 static int postcopy_start(MigrationState *ms)
1890 int ret;
1891 QIOChannelBuffer *bioc;
1892 QEMUFile *fb;
1893 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1894 bool restart_block = false;
1895 int cur_state = MIGRATION_STATUS_ACTIVE;
1896 if (!migrate_pause_before_switchover()) {
1897 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
1898 MIGRATION_STATUS_POSTCOPY_ACTIVE);
1901 trace_postcopy_start();
1902 qemu_mutex_lock_iothread();
1903 trace_postcopy_start_set_run();
1905 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
1906 global_state_store();
1907 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
1908 if (ret < 0) {
1909 goto fail;
1912 ret = migration_maybe_pause(ms, &cur_state,
1913 MIGRATION_STATUS_POSTCOPY_ACTIVE);
1914 if (ret < 0) {
1915 goto fail;
1918 ret = bdrv_inactivate_all();
1919 if (ret < 0) {
1920 goto fail;
1922 restart_block = true;
1925 * Cause any non-postcopiable, but iterative devices to
1926 * send out their final data.
1928 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false);
1931 * in Finish migrate and with the io-lock held everything should
1932 * be quiet, but we've potentially still got dirty pages and we
1933 * need to tell the destination to throw any pages it's already received
1934 * that are dirty
1936 if (migrate_postcopy_ram()) {
1937 if (ram_postcopy_send_discard_bitmap(ms)) {
1938 error_report("postcopy send discard bitmap failed");
1939 goto fail;
1944 * send rest of state - note things that are doing postcopy
1945 * will notice we're in POSTCOPY_ACTIVE and not actually
1946 * wrap their state up here
1948 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);
1949 if (migrate_postcopy_ram()) {
1950 /* Ping just for debugging, helps line traces up */
1951 qemu_savevm_send_ping(ms->to_dst_file, 2);
1955 * While loading the device state we may trigger page transfer
1956 * requests and the fd must be free to process those, and thus
1957 * the destination must read the whole device state off the fd before
1958 * it starts processing it. Unfortunately the ad-hoc migration format
1959 * doesn't allow the destination to know the size to read without fully
1960 * parsing it through each devices load-state code (especially the open
1961 * coded devices that use get/put).
1962 * So we wrap the device state up in a package with a length at the start;
1963 * to do this we use a qemu_buf to hold the whole of the device state.
1965 bioc = qio_channel_buffer_new(4096);
1966 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");
1967 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
1968 object_unref(OBJECT(bioc));
1971 * Make sure the receiver can get incoming pages before we send the rest
1972 * of the state
1974 qemu_savevm_send_postcopy_listen(fb);
1976 qemu_savevm_state_complete_precopy(fb, false, false);
1977 if (migrate_postcopy_ram()) {
1978 qemu_savevm_send_ping(fb, 3);
1981 qemu_savevm_send_postcopy_run(fb);
1983 /* <><> end of stuff going into the package */
1985 /* Last point of recovery; as soon as we send the package the destination
1986 * can open devices and potentially start running.
1987 * Lets just check again we've not got any errors.
1989 ret = qemu_file_get_error(ms->to_dst_file);
1990 if (ret) {
1991 error_report("postcopy_start: Migration stream errored (pre package)");
1992 goto fail_closefb;
1995 restart_block = false;
1997 /* Now send that blob */
1998 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) {
1999 goto fail_closefb;
2001 qemu_fclose(fb);
2003 /* Send a notify to give a chance for anything that needs to happen
2004 * at the transition to postcopy and after the device state; in particular
2005 * spice needs to trigger a transition now
2007 ms->postcopy_after_devices = true;
2008 notifier_list_notify(&migration_state_notifiers, ms);
2010 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
2012 qemu_mutex_unlock_iothread();
2014 if (migrate_postcopy_ram()) {
2016 * Although this ping is just for debug, it could potentially be
2017 * used for getting a better measurement of downtime at the source.
2019 qemu_savevm_send_ping(ms->to_dst_file, 4);
2022 if (migrate_release_ram()) {
2023 ram_postcopy_migrated_memory_release(ms);
2026 ret = qemu_file_get_error(ms->to_dst_file);
2027 if (ret) {
2028 error_report("postcopy_start: Migration stream errored");
2029 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2030 MIGRATION_STATUS_FAILED);
2033 return ret;
2035 fail_closefb:
2036 qemu_fclose(fb);
2037 fail:
2038 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2039 MIGRATION_STATUS_FAILED);
2040 if (restart_block) {
2041 /* A failure happened early enough that we know the destination hasn't
2042 * accessed block devices, so we're safe to recover.
2044 Error *local_err = NULL;
2046 bdrv_invalidate_cache_all(&local_err);
2047 if (local_err) {
2048 error_report_err(local_err);
2051 qemu_mutex_unlock_iothread();
2052 return -1;
2056 * migration_maybe_pause: Pause if required to by
2057 * migrate_pause_before_switchover called with the iothread locked
2058 * Returns: 0 on success
2060 static int migration_maybe_pause(MigrationState *s,
2061 int *current_active_state,
2062 int new_state)
2064 if (!migrate_pause_before_switchover()) {
2065 return 0;
2068 /* Since leaving this state is not atomic with posting the semaphore
2069 * it's possible that someone could have issued multiple migrate_continue
2070 * and the semaphore is incorrectly positive at this point;
2071 * the docs say it's undefined to reinit a semaphore that's already
2072 * init'd, so use timedwait to eat up any existing posts.
2074 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
2075 /* This block intentionally left blank */
2078 qemu_mutex_unlock_iothread();
2079 migrate_set_state(&s->state, *current_active_state,
2080 MIGRATION_STATUS_PRE_SWITCHOVER);
2081 qemu_sem_wait(&s->pause_sem);
2082 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
2083 new_state);
2084 *current_active_state = new_state;
2085 qemu_mutex_lock_iothread();
2087 return s->state == new_state ? 0 : -EINVAL;
2091 * migration_completion: Used by migration_thread when there's not much left.
2092 * The caller 'breaks' the loop when this returns.
2094 * @s: Current migration state
2096 static void migration_completion(MigrationState *s)
2098 int ret;
2099 int current_active_state = s->state;
2101 if (s->state == MIGRATION_STATUS_ACTIVE) {
2102 qemu_mutex_lock_iothread();
2103 s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2104 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
2105 s->vm_was_running = runstate_is_running();
2106 ret = global_state_store();
2108 if (!ret) {
2109 bool inactivate = !migrate_colo_enabled();
2110 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2111 if (ret >= 0) {
2112 ret = migration_maybe_pause(s, &current_active_state,
2113 MIGRATION_STATUS_DEVICE);
2115 if (ret >= 0) {
2116 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
2117 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
2118 inactivate);
2120 if (inactivate && ret >= 0) {
2121 s->block_inactive = true;
2124 qemu_mutex_unlock_iothread();
2126 if (ret < 0) {
2127 goto fail;
2129 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2130 trace_migration_completion_postcopy_end();
2132 qemu_savevm_state_complete_postcopy(s->to_dst_file);
2133 trace_migration_completion_postcopy_end_after_complete();
2137 * If rp was opened we must clean up the thread before
2138 * cleaning everything else up (since if there are no failures
2139 * it will wait for the destination to send it's status in
2140 * a SHUT command).
2142 if (s->rp_state.from_dst_file) {
2143 int rp_error;
2144 trace_migration_return_path_end_before();
2145 rp_error = await_return_path_close_on_source(s);
2146 trace_migration_return_path_end_after(rp_error);
2147 if (rp_error) {
2148 goto fail_invalidate;
2152 if (qemu_file_get_error(s->to_dst_file)) {
2153 trace_migration_completion_file_err();
2154 goto fail_invalidate;
2157 if (!migrate_colo_enabled()) {
2158 migrate_set_state(&s->state, current_active_state,
2159 MIGRATION_STATUS_COMPLETED);
2162 return;
2164 fail_invalidate:
2165 /* If not doing postcopy, vm_start() will be called: let's regain
2166 * control on images.
2168 if (s->state == MIGRATION_STATUS_ACTIVE) {
2169 Error *local_err = NULL;
2171 qemu_mutex_lock_iothread();
2172 bdrv_invalidate_cache_all(&local_err);
2173 if (local_err) {
2174 error_report_err(local_err);
2175 } else {
2176 s->block_inactive = false;
2178 qemu_mutex_unlock_iothread();
2181 fail:
2182 migrate_set_state(&s->state, current_active_state,
2183 MIGRATION_STATUS_FAILED);
2186 bool migrate_colo_enabled(void)
2188 MigrationState *s = migrate_get_current();
2189 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
2192 static void migration_calculate_complete(MigrationState *s)
2194 uint64_t bytes = qemu_ftell(s->to_dst_file);
2195 int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2197 s->total_time = end_time - s->start_time;
2198 if (!s->downtime) {
2200 * It's still not set, so we are precopy migration. For
2201 * postcopy, downtime is calculated during postcopy_start().
2203 s->downtime = end_time - s->downtime_start;
2206 if (s->total_time) {
2207 s->mbps = ((double) bytes * 8.0) / s->total_time / 1000;
2211 static void migration_update_counters(MigrationState *s,
2212 int64_t current_time)
2214 uint64_t transferred, time_spent;
2215 int64_t threshold_size;
2216 double bandwidth;
2218 if (current_time < s->iteration_start_time + BUFFER_DELAY) {
2219 return;
2222 transferred = qemu_ftell(s->to_dst_file) - s->iteration_initial_bytes;
2223 time_spent = current_time - s->iteration_start_time;
2224 bandwidth = (double)transferred / time_spent;
2225 threshold_size = bandwidth * s->parameters.downtime_limit;
2227 s->mbps = (((double) transferred * 8.0) /
2228 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
2231 * if we haven't sent anything, we don't want to
2232 * recalculate. 10000 is a small enough number for our purposes
2234 if (ram_counters.dirty_pages_rate && transferred > 10000) {
2235 s->expected_downtime = ram_counters.dirty_pages_rate *
2236 qemu_target_page_size() / bandwidth;
2239 qemu_file_reset_rate_limit(s->to_dst_file);
2241 s->iteration_start_time = current_time;
2242 s->iteration_initial_bytes = qemu_ftell(s->to_dst_file);
2244 trace_migrate_transferred(transferred, time_spent,
2245 bandwidth, threshold_size);
2248 /* Migration thread iteration status */
2249 typedef enum {
2250 MIG_ITERATE_RESUME, /* Resume current iteration */
2251 MIG_ITERATE_SKIP, /* Skip current iteration */
2252 MIG_ITERATE_BREAK, /* Break the loop */
2253 } MigIterateState;
2256 * Return true if continue to the next iteration directly, false
2257 * otherwise.
2259 static MigIterateState migration_iteration_run(MigrationState *s)
2261 uint64_t pending_size, pend_post, pend_nonpost;
2262 bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE;
2264 qemu_savevm_state_pending(s->to_dst_file, s->threshold_size,
2265 &pend_nonpost, &pend_post);
2266 pending_size = pend_nonpost + pend_post;
2268 trace_migrate_pending(pending_size, s->threshold_size,
2269 pend_post, pend_nonpost);
2271 if (pending_size && pending_size >= s->threshold_size) {
2272 /* Still a significant amount to transfer */
2273 if (migrate_postcopy() && !in_postcopy &&
2274 pend_nonpost <= s->threshold_size &&
2275 atomic_read(&s->start_postcopy)) {
2276 if (postcopy_start(s)) {
2277 error_report("%s: postcopy failed to start", __func__);
2279 return MIG_ITERATE_SKIP;
2281 /* Just another iteration step */
2282 qemu_savevm_state_iterate(s->to_dst_file,
2283 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
2284 } else {
2285 trace_migration_thread_low_pending(pending_size);
2286 migration_completion(s);
2287 return MIG_ITERATE_BREAK;
2290 return MIG_ITERATE_RESUME;
2293 static void migration_iteration_finish(MigrationState *s)
2295 /* If we enabled cpu throttling for auto-converge, turn it off. */
2296 cpu_throttle_stop();
2298 qemu_mutex_lock_iothread();
2299 switch (s->state) {
2300 case MIGRATION_STATUS_COMPLETED:
2301 migration_calculate_complete(s);
2302 runstate_set(RUN_STATE_POSTMIGRATE);
2303 break;
2305 case MIGRATION_STATUS_ACTIVE:
2307 * We should really assert here, but since it's during
2308 * migration, let's try to reduce the usage of assertions.
2310 if (!migrate_colo_enabled()) {
2311 error_report("%s: critical error: calling COLO code without "
2312 "COLO enabled", __func__);
2314 migrate_start_colo_process(s);
2316 * Fixme: we will run VM in COLO no matter its old running state.
2317 * After exited COLO, we will keep running.
2319 s->vm_was_running = true;
2320 /* Fallthrough */
2321 case MIGRATION_STATUS_FAILED:
2322 case MIGRATION_STATUS_CANCELLED:
2323 if (s->vm_was_running) {
2324 vm_start();
2325 } else {
2326 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
2327 runstate_set(RUN_STATE_POSTMIGRATE);
2330 break;
2332 default:
2333 /* Should not reach here, but if so, forgive the VM. */
2334 error_report("%s: Unknown ending state %d", __func__, s->state);
2335 break;
2337 qemu_bh_schedule(s->cleanup_bh);
2338 qemu_mutex_unlock_iothread();
2342 * Master migration thread on the source VM.
2343 * It drives the migration and pumps the data down the outgoing channel.
2345 static void *migration_thread(void *opaque)
2347 MigrationState *s = opaque;
2348 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
2350 rcu_register_thread();
2352 s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2354 qemu_savevm_state_header(s->to_dst_file);
2357 * If we opened the return path, we need to make sure dst has it
2358 * opened as well.
2360 if (s->rp_state.from_dst_file) {
2361 /* Now tell the dest that it should open its end so it can reply */
2362 qemu_savevm_send_open_return_path(s->to_dst_file);
2364 /* And do a ping that will make stuff easier to debug */
2365 qemu_savevm_send_ping(s->to_dst_file, 1);
2368 if (migrate_postcopy()) {
2370 * Tell the destination that we *might* want to do postcopy later;
2371 * if the other end can't do postcopy it should fail now, nice and
2372 * early.
2374 qemu_savevm_send_postcopy_advise(s->to_dst_file);
2377 qemu_savevm_state_setup(s->to_dst_file);
2379 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
2380 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2381 MIGRATION_STATUS_ACTIVE);
2383 trace_migration_thread_setup_complete();
2385 while (s->state == MIGRATION_STATUS_ACTIVE ||
2386 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2387 int64_t current_time;
2389 if (!qemu_file_rate_limit(s->to_dst_file)) {
2390 MigIterateState iter_state = migration_iteration_run(s);
2391 if (iter_state == MIG_ITERATE_SKIP) {
2392 continue;
2393 } else if (iter_state == MIG_ITERATE_BREAK) {
2394 break;
2398 if (qemu_file_get_error(s->to_dst_file)) {
2399 if (migration_is_setup_or_active(s->state)) {
2400 migrate_set_state(&s->state, s->state,
2401 MIGRATION_STATUS_FAILED);
2403 trace_migration_thread_file_err();
2404 break;
2407 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2409 migration_update_counters(s, current_time);
2411 if (qemu_file_rate_limit(s->to_dst_file)) {
2412 /* usleep expects microseconds */
2413 g_usleep((s->iteration_start_time + BUFFER_DELAY -
2414 current_time) * 1000);
2418 trace_migration_thread_after_loop();
2419 migration_iteration_finish(s);
2420 rcu_unregister_thread();
2421 return NULL;
2424 void migrate_fd_connect(MigrationState *s)
2426 s->expected_downtime = s->parameters.downtime_limit;
2427 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
2429 qemu_file_set_blocking(s->to_dst_file, true);
2430 qemu_file_set_rate_limit(s->to_dst_file,
2431 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
2433 /* Notify before starting migration thread */
2434 notifier_list_notify(&migration_state_notifiers, s);
2437 * Open the return path. For postcopy, it is used exclusively. For
2438 * precopy, only if user specified "return-path" capability would
2439 * QEMU uses the return path.
2441 if (migrate_postcopy_ram() || migrate_use_return_path()) {
2442 if (open_return_path_on_source(s)) {
2443 error_report("Unable to open return-path for postcopy");
2444 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2445 MIGRATION_STATUS_FAILED);
2446 migrate_fd_cleanup(s);
2447 return;
2451 if (multifd_save_setup() != 0) {
2452 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2453 MIGRATION_STATUS_FAILED);
2454 migrate_fd_cleanup(s);
2455 return;
2457 qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
2458 QEMU_THREAD_JOINABLE);
2459 s->migration_thread_running = true;
2462 void migration_global_dump(Monitor *mon)
2464 MigrationState *ms = migrate_get_current();
2466 monitor_printf(mon, "globals:\n");
2467 monitor_printf(mon, "store-global-state: %s\n",
2468 ms->store_global_state ? "on" : "off");
2469 monitor_printf(mon, "only-migratable: %s\n",
2470 ms->only_migratable ? "on" : "off");
2471 monitor_printf(mon, "send-configuration: %s\n",
2472 ms->send_configuration ? "on" : "off");
2473 monitor_printf(mon, "send-section-footer: %s\n",
2474 ms->send_section_footer ? "on" : "off");
2477 #define DEFINE_PROP_MIG_CAP(name, x) \
2478 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false)
2480 static Property migration_properties[] = {
2481 DEFINE_PROP_BOOL("store-global-state", MigrationState,
2482 store_global_state, true),
2483 DEFINE_PROP_BOOL("only-migratable", MigrationState, only_migratable, false),
2484 DEFINE_PROP_BOOL("send-configuration", MigrationState,
2485 send_configuration, true),
2486 DEFINE_PROP_BOOL("send-section-footer", MigrationState,
2487 send_section_footer, true),
2489 /* Migration parameters */
2490 DEFINE_PROP_UINT8("x-compress-level", MigrationState,
2491 parameters.compress_level,
2492 DEFAULT_MIGRATE_COMPRESS_LEVEL),
2493 DEFINE_PROP_UINT8("x-compress-threads", MigrationState,
2494 parameters.compress_threads,
2495 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT),
2496 DEFINE_PROP_UINT8("x-decompress-threads", MigrationState,
2497 parameters.decompress_threads,
2498 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT),
2499 DEFINE_PROP_UINT8("x-cpu-throttle-initial", MigrationState,
2500 parameters.cpu_throttle_initial,
2501 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL),
2502 DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState,
2503 parameters.cpu_throttle_increment,
2504 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT),
2505 DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState,
2506 parameters.max_bandwidth, MAX_THROTTLE),
2507 DEFINE_PROP_UINT64("x-downtime-limit", MigrationState,
2508 parameters.downtime_limit,
2509 DEFAULT_MIGRATE_SET_DOWNTIME),
2510 DEFINE_PROP_UINT32("x-checkpoint-delay", MigrationState,
2511 parameters.x_checkpoint_delay,
2512 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY),
2513 DEFINE_PROP_UINT8("x-multifd-channels", MigrationState,
2514 parameters.x_multifd_channels,
2515 DEFAULT_MIGRATE_MULTIFD_CHANNELS),
2516 DEFINE_PROP_UINT32("x-multifd-page-count", MigrationState,
2517 parameters.x_multifd_page_count,
2518 DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT),
2519 DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState,
2520 parameters.xbzrle_cache_size,
2521 DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE),
2523 /* Migration capabilities */
2524 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
2525 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL),
2526 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE),
2527 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS),
2528 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS),
2529 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS),
2530 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM),
2531 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO),
2532 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM),
2533 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK),
2534 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH),
2535 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_X_MULTIFD),
2537 DEFINE_PROP_END_OF_LIST(),
2540 static void migration_class_init(ObjectClass *klass, void *data)
2542 DeviceClass *dc = DEVICE_CLASS(klass);
2544 dc->user_creatable = false;
2545 dc->props = migration_properties;
2548 static void migration_instance_finalize(Object *obj)
2550 MigrationState *ms = MIGRATION_OBJ(obj);
2551 MigrationParameters *params = &ms->parameters;
2553 qemu_mutex_destroy(&ms->error_mutex);
2554 g_free(params->tls_hostname);
2555 g_free(params->tls_creds);
2556 qemu_sem_destroy(&ms->pause_sem);
2559 static void migration_instance_init(Object *obj)
2561 MigrationState *ms = MIGRATION_OBJ(obj);
2562 MigrationParameters *params = &ms->parameters;
2564 ms->state = MIGRATION_STATUS_NONE;
2565 ms->mbps = -1;
2566 qemu_sem_init(&ms->pause_sem, 0);
2567 qemu_mutex_init(&ms->error_mutex);
2569 params->tls_hostname = g_strdup("");
2570 params->tls_creds = g_strdup("");
2572 /* Set has_* up only for parameter checks */
2573 params->has_compress_level = true;
2574 params->has_compress_threads = true;
2575 params->has_decompress_threads = true;
2576 params->has_cpu_throttle_initial = true;
2577 params->has_cpu_throttle_increment = true;
2578 params->has_max_bandwidth = true;
2579 params->has_downtime_limit = true;
2580 params->has_x_checkpoint_delay = true;
2581 params->has_block_incremental = true;
2582 params->has_x_multifd_channels = true;
2583 params->has_x_multifd_page_count = true;
2584 params->has_xbzrle_cache_size = true;
2588 * Return true if check pass, false otherwise. Error will be put
2589 * inside errp if provided.
2591 static bool migration_object_check(MigrationState *ms, Error **errp)
2593 MigrationCapabilityStatusList *head = NULL;
2594 /* Assuming all off */
2595 bool cap_list[MIGRATION_CAPABILITY__MAX] = { 0 }, ret;
2596 int i;
2598 if (!migrate_params_check(&ms->parameters, errp)) {
2599 return false;
2602 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
2603 if (ms->enabled_capabilities[i]) {
2604 head = migrate_cap_add(head, i, true);
2608 ret = migrate_caps_check(cap_list, head, errp);
2610 /* It works with head == NULL */
2611 qapi_free_MigrationCapabilityStatusList(head);
2613 return ret;
2616 static const TypeInfo migration_type = {
2617 .name = TYPE_MIGRATION,
2619 * NOTE: TYPE_MIGRATION is not really a device, as the object is
2620 * not created using qdev_create(), it is not attached to the qdev
2621 * device tree, and it is never realized.
2623 * TODO: Make this TYPE_OBJECT once QOM provides something like
2624 * TYPE_DEVICE's "-global" properties.
2626 .parent = TYPE_DEVICE,
2627 .class_init = migration_class_init,
2628 .class_size = sizeof(MigrationClass),
2629 .instance_size = sizeof(MigrationState),
2630 .instance_init = migration_instance_init,
2631 .instance_finalize = migration_instance_finalize,
2634 static void register_migration_types(void)
2636 type_register_static(&migration_type);
2639 type_init(register_migration_types);