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migration: migrate-continue
[qemu.git] / migration / migration.c
blob90bfdc3a7c2c17471da425747f860fd94a7e2be1
1 /*
2 * QEMU live migration
3 *
4 * Copyright IBM, Corp. 2008
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 *
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.
14 */
15
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"
46
47 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
48
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)
53
54 /* Time in milliseconds we are allowed to stop the source,
55 * for sending the last part */
56 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
57
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)
61
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
72
73 /* Migration XBZRLE default cache size */
74 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
75
76 /* The delay time (in ms) between two COLO checkpoints
77 * Note: Please change this default value to 10000 when we support hybrid mode.
78 */
79 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200
80 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
81 #define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16
82
83 static NotifierList migration_state_notifiers =
84 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
85
86 static bool deferred_incoming;
87
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 ) */
93
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) */
96
97 MIG_RP_MSG_MAX
98 };
99
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 */
103
104 static MigrationState *current_migration;
105
106 static bool migration_object_check(MigrationState *ms, Error **errp);
107
108 void migration_object_init(void)
109 {
110 MachineState *ms = MACHINE(qdev_get_machine());
111 Error *err = NULL;
112
113 /* This can only be called once. */
114 assert(!current_migration);
115 current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
116
117 if (!migration_object_check(current_migration, &err)) {
118 error_report_err(err);
119 exit(1);
120 }
121
122 /*
123 * We cannot really do this in migration_instance_init() since at
124 * that time global properties are not yet applied, then this
125 * value will be definitely replaced by something else.
126 */
127 if (ms->enforce_config_section) {
128 current_migration->send_configuration = true;
129 }
130 }
131
132 /* For outgoing */
133 MigrationState *migrate_get_current(void)
134 {
135 /* This can only be called after the object created. */
136 assert(current_migration);
137 return current_migration;
138 }
139
140 MigrationIncomingState *migration_incoming_get_current(void)
141 {
142 static bool once;
143 static MigrationIncomingState mis_current;
144
145 if (!once) {
146 mis_current.state = MIGRATION_STATUS_NONE;
147 memset(&mis_current, 0, sizeof(MigrationIncomingState));
148 qemu_mutex_init(&mis_current.rp_mutex);
149 qemu_event_init(&mis_current.main_thread_load_event, false);
150 once = true;
151 }
152 return &mis_current;
153 }
154
155 void migration_incoming_state_destroy(void)
156 {
157 struct MigrationIncomingState *mis = migration_incoming_get_current();
158
159 if (mis->to_src_file) {
160 /* Tell source that we are done */
161 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
162 qemu_fclose(mis->to_src_file);
163 mis->to_src_file = NULL;
164 }
165
166 if (mis->from_src_file) {
167 qemu_fclose(mis->from_src_file);
168 mis->from_src_file = NULL;
169 }
170
171 qemu_event_reset(&mis->main_thread_load_event);
172 }
173
174 static void migrate_generate_event(int new_state)
175 {
176 if (migrate_use_events()) {
177 qapi_event_send_migration(new_state, &error_abort);
178 }
179 }
180
181 /*
182 * Called on -incoming with a defer: uri.
183 * The migration can be started later after any parameters have been
184 * changed.
185 */
186 static void deferred_incoming_migration(Error **errp)
187 {
188 if (deferred_incoming) {
189 error_setg(errp, "Incoming migration already deferred");
190 }
191 deferred_incoming = true;
192 }
193
194 /*
195 * Send a message on the return channel back to the source
196 * of the migration.
197 */
198 static void migrate_send_rp_message(MigrationIncomingState *mis,
199 enum mig_rp_message_type message_type,
200 uint16_t len, void *data)
201 {
202 trace_migrate_send_rp_message((int)message_type, len);
203 qemu_mutex_lock(&mis->rp_mutex);
204 qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
205 qemu_put_be16(mis->to_src_file, len);
206 qemu_put_buffer(mis->to_src_file, data, len);
207 qemu_fflush(mis->to_src_file);
208 qemu_mutex_unlock(&mis->rp_mutex);
209 }
210
211 /* Request a range of pages from the source VM at the given
212 * start address.
213 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
214 * as the last request (a name must have been given previously)
215 * Start: Address offset within the RB
216 * Len: Length in bytes required - must be a multiple of pagesize
217 */
218 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
219 ram_addr_t start, size_t len)
220 {
221 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
222 size_t msglen = 12; /* start + len */
223
224 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
225 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
226
227 if (rbname) {
228 int rbname_len = strlen(rbname);
229 assert(rbname_len < 256);
230
231 bufc[msglen++] = rbname_len;
232 memcpy(bufc + msglen, rbname, rbname_len);
233 msglen += rbname_len;
234 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc);
235 } else {
236 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc);
237 }
238 }
239
240 void qemu_start_incoming_migration(const char *uri, Error **errp)
241 {
242 const char *p;
243
244 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort);
245 if (!strcmp(uri, "defer")) {
246 deferred_incoming_migration(errp);
247 } else if (strstart(uri, "tcp:", &p)) {
248 tcp_start_incoming_migration(p, errp);
249 #ifdef CONFIG_RDMA
250 } else if (strstart(uri, "rdma:", &p)) {
251 rdma_start_incoming_migration(p, errp);
252 #endif
253 } else if (strstart(uri, "exec:", &p)) {
254 exec_start_incoming_migration(p, errp);
255 } else if (strstart(uri, "unix:", &p)) {
256 unix_start_incoming_migration(p, errp);
257 } else if (strstart(uri, "fd:", &p)) {
258 fd_start_incoming_migration(p, errp);
259 } else {
260 error_setg(errp, "unknown migration protocol: %s", uri);
261 }
262 }
263
264 static void process_incoming_migration_bh(void *opaque)
265 {
266 Error *local_err = NULL;
267 MigrationIncomingState *mis = opaque;
268
269 /* Make sure all file formats flush their mutable metadata.
270 * If we get an error here, just don't restart the VM yet. */
271 bdrv_invalidate_cache_all(&local_err);
272 if (local_err) {
273 error_report_err(local_err);
274 local_err = NULL;
275 autostart = false;
276 }
277
278 /*
279 * This must happen after all error conditions are dealt with and
280 * we're sure the VM is going to be running on this host.
281 */
282 qemu_announce_self();
283
284 if (multifd_load_cleanup(&local_err) != 0) {
285 error_report_err(local_err);
286 autostart = false;
287 }
288 /* If global state section was not received or we are in running
289 state, we need to obey autostart. Any other state is set with
290 runstate_set. */
291
292 if (!global_state_received() ||
293 global_state_get_runstate() == RUN_STATE_RUNNING) {
294 if (autostart) {
295 vm_start();
296 } else {
297 runstate_set(RUN_STATE_PAUSED);
298 }
299 } else {
300 runstate_set(global_state_get_runstate());
301 }
302 /*
303 * This must happen after any state changes since as soon as an external
304 * observer sees this event they might start to prod at the VM assuming
305 * it's ready to use.
306 */
307 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
308 MIGRATION_STATUS_COMPLETED);
309 qemu_bh_delete(mis->bh);
310 migration_incoming_state_destroy();
311 }
312
313 static void process_incoming_migration_co(void *opaque)
314 {
315 MigrationIncomingState *mis = migration_incoming_get_current();
316 PostcopyState ps;
317 int ret;
318
319 assert(mis->from_src_file);
320 mis->largest_page_size = qemu_ram_pagesize_largest();
321 postcopy_state_set(POSTCOPY_INCOMING_NONE);
322 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
323 MIGRATION_STATUS_ACTIVE);
324 ret = qemu_loadvm_state(mis->from_src_file);
325
326 ps = postcopy_state_get();
327 trace_process_incoming_migration_co_end(ret, ps);
328 if (ps != POSTCOPY_INCOMING_NONE) {
329 if (ps == POSTCOPY_INCOMING_ADVISE) {
330 /*
331 * Where a migration had postcopy enabled (and thus went to advise)
332 * but managed to complete within the precopy period, we can use
333 * the normal exit.
334 */
335 postcopy_ram_incoming_cleanup(mis);
336 } else if (ret >= 0) {
337 /*
338 * Postcopy was started, cleanup should happen at the end of the
339 * postcopy thread.
340 */
341 trace_process_incoming_migration_co_postcopy_end_main();
342 return;
343 }
344 /* Else if something went wrong then just fall out of the normal exit */
345 }
346
347 /* we get COLO info, and know if we are in COLO mode */
348 if (!ret && migration_incoming_enable_colo()) {
349 mis->migration_incoming_co = qemu_coroutine_self();
350 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming",
351 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
352 mis->have_colo_incoming_thread = true;
353 qemu_coroutine_yield();
354
355 /* Wait checkpoint incoming thread exit before free resource */
356 qemu_thread_join(&mis->colo_incoming_thread);
357 }
358
359 if (ret < 0) {
360 Error *local_err = NULL;
361
362 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
363 MIGRATION_STATUS_FAILED);
364 error_report("load of migration failed: %s", strerror(-ret));
365 qemu_fclose(mis->from_src_file);
366 if (multifd_load_cleanup(&local_err) != 0) {
367 error_report_err(local_err);
368 }
369 exit(EXIT_FAILURE);
370 }
371 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
372 qemu_bh_schedule(mis->bh);
373 }
374
375 static void migration_incoming_setup(QEMUFile *f)
376 {
377 MigrationIncomingState *mis = migration_incoming_get_current();
378
379 if (multifd_load_setup() != 0) {
380 /* We haven't been able to create multifd threads
381 nothing better to do */
382 exit(EXIT_FAILURE);
383 }
384
385 if (!mis->from_src_file) {
386 mis->from_src_file = f;
387 }
388 qemu_file_set_blocking(f, false);
389 }
390
391 static void migration_incoming_process(void)
392 {
393 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
394 qemu_coroutine_enter(co);
395 }
396
397 void migration_fd_process_incoming(QEMUFile *f)
398 {
399 migration_incoming_setup(f);
400 migration_incoming_process();
401 }
402
403 void migration_ioc_process_incoming(QIOChannel *ioc)
404 {
405 MigrationIncomingState *mis = migration_incoming_get_current();
406
407 if (!mis->from_src_file) {
408 QEMUFile *f = qemu_fopen_channel_input(ioc);
409 migration_fd_process_incoming(f);
410 }
411 /* We still only have a single channel. Nothing to do here yet */
412 }
413
414 /**
415 * @migration_has_all_channels: We have received all channels that we need
416 *
417 * Returns true when we have got connections to all the channels that
418 * we need for migration.
419 */
420 bool migration_has_all_channels(void)
421 {
422 return true;
423 }
424
425 /*
426 * Send a 'SHUT' message on the return channel with the given value
427 * to indicate that we've finished with the RP. Non-0 value indicates
428 * error.
429 */
430 void migrate_send_rp_shut(MigrationIncomingState *mis,
431 uint32_t value)
432 {
433 uint32_t buf;
434
435 buf = cpu_to_be32(value);
436 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
437 }
438
439 /*
440 * Send a 'PONG' message on the return channel with the given value
441 * (normally in response to a 'PING')
442 */
443 void migrate_send_rp_pong(MigrationIncomingState *mis,
444 uint32_t value)
445 {
446 uint32_t buf;
447
448 buf = cpu_to_be32(value);
449 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
450 }
451
452 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
453 {
454 MigrationCapabilityStatusList *head = NULL;
455 MigrationCapabilityStatusList *caps;
456 MigrationState *s = migrate_get_current();
457 int i;
458
459 caps = NULL; /* silence compiler warning */
460 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
461 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
462 if (i == MIGRATION_CAPABILITY_BLOCK) {
463 continue;
464 }
465 #endif
466 if (head == NULL) {
467 head = g_malloc0(sizeof(*caps));
468 caps = head;
469 } else {
470 caps->next = g_malloc0(sizeof(*caps));
471 caps = caps->next;
472 }
473 caps->value =
474 g_malloc(sizeof(*caps->value));
475 caps->value->capability = i;
476 caps->value->state = s->enabled_capabilities[i];
477 }
478
479 return head;
480 }
481
482 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
483 {
484 MigrationParameters *params;
485 MigrationState *s = migrate_get_current();
486
487 /* TODO use QAPI_CLONE() instead of duplicating it inline */
488 params = g_malloc0(sizeof(*params));
489 params->has_compress_level = true;
490 params->compress_level = s->parameters.compress_level;
491 params->has_compress_threads = true;
492 params->compress_threads = s->parameters.compress_threads;
493 params->has_decompress_threads = true;
494 params->decompress_threads = s->parameters.decompress_threads;
495 params->has_cpu_throttle_initial = true;
496 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial;
497 params->has_cpu_throttle_increment = true;
498 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment;
499 params->has_tls_creds = true;
500 params->tls_creds = g_strdup(s->parameters.tls_creds);
501 params->has_tls_hostname = true;
502 params->tls_hostname = g_strdup(s->parameters.tls_hostname);
503 params->has_max_bandwidth = true;
504 params->max_bandwidth = s->parameters.max_bandwidth;
505 params->has_downtime_limit = true;
506 params->downtime_limit = s->parameters.downtime_limit;
507 params->has_x_checkpoint_delay = true;
508 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay;
509 params->has_block_incremental = true;
510 params->block_incremental = s->parameters.block_incremental;
511 params->has_x_multifd_channels = true;
512 params->x_multifd_channels = s->parameters.x_multifd_channels;
513 params->has_x_multifd_page_count = true;
514 params->x_multifd_page_count = s->parameters.x_multifd_page_count;
515
516 return params;
517 }
518
519 /*
520 * Return true if we're already in the middle of a migration
521 * (i.e. any of the active or setup states)
522 */
523 static bool migration_is_setup_or_active(int state)
524 {
525 switch (state) {
526 case MIGRATION_STATUS_ACTIVE:
527 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
528 case MIGRATION_STATUS_SETUP:
529 case MIGRATION_STATUS_PRE_SWITCHOVER:
530 case MIGRATION_STATUS_DEVICE:
531 return true;
532
533 default:
534 return false;
535
536 }
537 }
538
539 static void populate_ram_info(MigrationInfo *info, MigrationState *s)
540 {
541 info->has_ram = true;
542 info->ram = g_malloc0(sizeof(*info->ram));
543 info->ram->transferred = ram_counters.transferred;
544 info->ram->total = ram_bytes_total();
545 info->ram->duplicate = ram_counters.duplicate;
546 /* legacy value. It is not used anymore */
547 info->ram->skipped = 0;
548 info->ram->normal = ram_counters.normal;
549 info->ram->normal_bytes = ram_counters.normal *
550 qemu_target_page_size();
551 info->ram->mbps = s->mbps;
552 info->ram->dirty_sync_count = ram_counters.dirty_sync_count;
553 info->ram->postcopy_requests = ram_counters.postcopy_requests;
554 info->ram->page_size = qemu_target_page_size();
555
556 if (migrate_use_xbzrle()) {
557 info->has_xbzrle_cache = true;
558 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
559 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
560 info->xbzrle_cache->bytes = xbzrle_counters.bytes;
561 info->xbzrle_cache->pages = xbzrle_counters.pages;
562 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss;
563 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate;
564 info->xbzrle_cache->overflow = xbzrle_counters.overflow;
565 }
566
567 if (cpu_throttle_active()) {
568 info->has_cpu_throttle_percentage = true;
569 info->cpu_throttle_percentage = cpu_throttle_get_percentage();
570 }
571
572 if (s->state != MIGRATION_STATUS_COMPLETED) {
573 info->ram->remaining = ram_bytes_remaining();
574 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate;
575 }
576 }
577
578 static void populate_disk_info(MigrationInfo *info)
579 {
580 if (blk_mig_active()) {
581 info->has_disk = true;
582 info->disk = g_malloc0(sizeof(*info->disk));
583 info->disk->transferred = blk_mig_bytes_transferred();
584 info->disk->remaining = blk_mig_bytes_remaining();
585 info->disk->total = blk_mig_bytes_total();
586 }
587 }
588
589 MigrationInfo *qmp_query_migrate(Error **errp)
590 {
591 MigrationInfo *info = g_malloc0(sizeof(*info));
592 MigrationState *s = migrate_get_current();
593
594 switch (s->state) {
595 case MIGRATION_STATUS_NONE:
596 /* no migration has happened ever */
597 break;
598 case MIGRATION_STATUS_SETUP:
599 info->has_status = true;
600 info->has_total_time = false;
601 break;
602 case MIGRATION_STATUS_ACTIVE:
603 case MIGRATION_STATUS_CANCELLING:
604 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
605 case MIGRATION_STATUS_PRE_SWITCHOVER:
606 case MIGRATION_STATUS_DEVICE:
607 /* TODO add some postcopy stats */
608 info->has_status = true;
609 info->has_total_time = true;
610 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
611 - s->total_time;
612 info->has_expected_downtime = true;
613 info->expected_downtime = s->expected_downtime;
614 info->has_setup_time = true;
615 info->setup_time = s->setup_time;
616
617 populate_ram_info(info, s);
618 populate_disk_info(info);
619 break;
620 case MIGRATION_STATUS_COLO:
621 info->has_status = true;
622 /* TODO: display COLO specific information (checkpoint info etc.) */
623 break;
624 case MIGRATION_STATUS_COMPLETED:
625 info->has_status = true;
626 info->has_total_time = true;
627 info->total_time = s->total_time;
628 info->has_downtime = true;
629 info->downtime = s->downtime;
630 info->has_setup_time = true;
631 info->setup_time = s->setup_time;
632
633 populate_ram_info(info, s);
634 break;
635 case MIGRATION_STATUS_FAILED:
636 info->has_status = true;
637 if (s->error) {
638 info->has_error_desc = true;
639 info->error_desc = g_strdup(error_get_pretty(s->error));
640 }
641 break;
642 case MIGRATION_STATUS_CANCELLED:
643 info->has_status = true;
644 break;
645 }
646 info->status = s->state;
647
648 return info;
649 }
650
651 /**
652 * @migration_caps_check - check capability validity
653 *
654 * @cap_list: old capability list, array of bool
655 * @params: new capabilities to be applied soon
656 * @errp: set *errp if the check failed, with reason
657 *
658 * Returns true if check passed, otherwise false.
659 */
660 static bool migrate_caps_check(bool *cap_list,
661 MigrationCapabilityStatusList *params,
662 Error **errp)
663 {
664 MigrationCapabilityStatusList *cap;
665 bool old_postcopy_cap;
666 MigrationIncomingState *mis = migration_incoming_get_current();
667
668 old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM];
669
670 for (cap = params; cap; cap = cap->next) {
671 cap_list[cap->value->capability] = cap->value->state;
672 }
673
674 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
675 if (cap_list[MIGRATION_CAPABILITY_BLOCK]) {
676 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) "
677 "block migration");
678 error_append_hint(errp, "Use drive_mirror+NBD instead.\n");
679 return false;
680 }
681 #endif
682
683 if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) {
684 if (cap_list[MIGRATION_CAPABILITY_COMPRESS]) {
685 /* The decompression threads asynchronously write into RAM
686 * rather than use the atomic copies needed to avoid
687 * userfaulting. It should be possible to fix the decompression
688 * threads for compatibility in future.
689 */
690 error_setg(errp, "Postcopy is not currently compatible "
691 "with compression");
692 return false;
693 }
694
695 /* This check is reasonably expensive, so only when it's being
696 * set the first time, also it's only the destination that needs
697 * special support.
698 */
699 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) &&
700 !postcopy_ram_supported_by_host(mis)) {
701 /* postcopy_ram_supported_by_host will have emitted a more
702 * detailed message
703 */
704 error_setg(errp, "Postcopy is not supported");
705 return false;
706 }
707 }
708
709 return true;
710 }
711
712 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
713 Error **errp)
714 {
715 MigrationState *s = migrate_get_current();
716 MigrationCapabilityStatusList *cap;
717
718 if (migration_is_setup_or_active(s->state)) {
719 error_setg(errp, QERR_MIGRATION_ACTIVE);
720 return;
721 }
722
723 if (!migrate_caps_check(s->enabled_capabilities, params, errp)) {
724 return;
725 }
726
727 for (cap = params; cap; cap = cap->next) {
728 s->enabled_capabilities[cap->value->capability] = cap->value->state;
729 }
730 }
731
732 /*
733 * Check whether the parameters are valid. Error will be put into errp
734 * (if provided). Return true if valid, otherwise false.
735 */
736 static bool migrate_params_check(MigrationParameters *params, Error **errp)
737 {
738 if (params->has_compress_level &&
739 (params->compress_level < 0 || params->compress_level > 9)) {
740 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
741 "is invalid, it should be in the range of 0 to 9");
742 return false;
743 }
744
745 if (params->has_compress_threads &&
746 (params->compress_threads < 1 || params->compress_threads > 255)) {
747 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
748 "compress_threads",
749 "is invalid, it should be in the range of 1 to 255");
750 return false;
751 }
752
753 if (params->has_decompress_threads &&
754 (params->decompress_threads < 1 || params->decompress_threads > 255)) {
755 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
756 "decompress_threads",
757 "is invalid, it should be in the range of 1 to 255");
758 return false;
759 }
760
761 if (params->has_cpu_throttle_initial &&
762 (params->cpu_throttle_initial < 1 ||
763 params->cpu_throttle_initial > 99)) {
764 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
765 "cpu_throttle_initial",
766 "an integer in the range of 1 to 99");
767 return false;
768 }
769
770 if (params->has_cpu_throttle_increment &&
771 (params->cpu_throttle_increment < 1 ||
772 params->cpu_throttle_increment > 99)) {
773 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
774 "cpu_throttle_increment",
775 "an integer in the range of 1 to 99");
776 return false;
777 }
778
779 if (params->has_max_bandwidth &&
780 (params->max_bandwidth < 0 || params->max_bandwidth > SIZE_MAX)) {
781 error_setg(errp, "Parameter 'max_bandwidth' expects an integer in the"
782 " range of 0 to %zu bytes/second", SIZE_MAX);
783 return false;
784 }
785
786 if (params->has_downtime_limit &&
787 (params->downtime_limit < 0 ||
788 params->downtime_limit > MAX_MIGRATE_DOWNTIME)) {
789 error_setg(errp, "Parameter 'downtime_limit' expects an integer in "
790 "the range of 0 to %d milliseconds",
791 MAX_MIGRATE_DOWNTIME);
792 return false;
793 }
794
795 if (params->has_x_checkpoint_delay && (params->x_checkpoint_delay < 0)) {
796 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
797 "x_checkpoint_delay",
798 "is invalid, it should be positive");
799 return false;
800 }
801 if (params->has_x_multifd_channels &&
802 (params->x_multifd_channels < 1 || params->x_multifd_channels > 255)) {
803 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
804 "multifd_channels",
805 "is invalid, it should be in the range of 1 to 255");
806 return false;
807 }
808 if (params->has_x_multifd_page_count &&
809 (params->x_multifd_page_count < 1 ||
810 params->x_multifd_page_count > 10000)) {
811 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
812 "multifd_page_count",
813 "is invalid, it should be in the range of 1 to 10000");
814 return false;
815 }
816
817 return true;
818 }
819
820 static void migrate_params_test_apply(MigrateSetParameters *params,
821 MigrationParameters *dest)
822 {
823 *dest = migrate_get_current()->parameters;
824
825 /* TODO use QAPI_CLONE() instead of duplicating it inline */
826
827 if (params->has_compress_level) {
828 dest->compress_level = params->compress_level;
829 }
830
831 if (params->has_compress_threads) {
832 dest->compress_threads = params->compress_threads;
833 }
834
835 if (params->has_decompress_threads) {
836 dest->decompress_threads = params->decompress_threads;
837 }
838
839 if (params->has_cpu_throttle_initial) {
840 dest->cpu_throttle_initial = params->cpu_throttle_initial;
841 }
842
843 if (params->has_cpu_throttle_increment) {
844 dest->cpu_throttle_increment = params->cpu_throttle_increment;
845 }
846
847 if (params->has_tls_creds) {
848 assert(params->tls_creds->type == QTYPE_QSTRING);
849 dest->tls_creds = g_strdup(params->tls_creds->u.s);
850 }
851
852 if (params->has_tls_hostname) {
853 assert(params->tls_hostname->type == QTYPE_QSTRING);
854 dest->tls_hostname = g_strdup(params->tls_hostname->u.s);
855 }
856
857 if (params->has_max_bandwidth) {
858 dest->max_bandwidth = params->max_bandwidth;
859 }
860
861 if (params->has_downtime_limit) {
862 dest->downtime_limit = params->downtime_limit;
863 }
864
865 if (params->has_x_checkpoint_delay) {
866 dest->x_checkpoint_delay = params->x_checkpoint_delay;
867 }
868
869 if (params->has_block_incremental) {
870 dest->block_incremental = params->block_incremental;
871 }
872 if (params->has_x_multifd_channels) {
873 dest->x_multifd_channels = params->x_multifd_channels;
874 }
875 if (params->has_x_multifd_page_count) {
876 dest->x_multifd_page_count = params->x_multifd_page_count;
877 }
878 }
879
880 static void migrate_params_apply(MigrateSetParameters *params)
881 {
882 MigrationState *s = migrate_get_current();
883
884 /* TODO use QAPI_CLONE() instead of duplicating it inline */
885
886 if (params->has_compress_level) {
887 s->parameters.compress_level = params->compress_level;
888 }
889
890 if (params->has_compress_threads) {
891 s->parameters.compress_threads = params->compress_threads;
892 }
893
894 if (params->has_decompress_threads) {
895 s->parameters.decompress_threads = params->decompress_threads;
896 }
897
898 if (params->has_cpu_throttle_initial) {
899 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial;
900 }
901
902 if (params->has_cpu_throttle_increment) {
903 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment;
904 }
905
906 if (params->has_tls_creds) {
907 g_free(s->parameters.tls_creds);
908 assert(params->tls_creds->type == QTYPE_QSTRING);
909 s->parameters.tls_creds = g_strdup(params->tls_creds->u.s);
910 }
911
912 if (params->has_tls_hostname) {
913 g_free(s->parameters.tls_hostname);
914 assert(params->tls_hostname->type == QTYPE_QSTRING);
915 s->parameters.tls_hostname = g_strdup(params->tls_hostname->u.s);
916 }
917
918 if (params->has_max_bandwidth) {
919 s->parameters.max_bandwidth = params->max_bandwidth;
920 if (s->to_dst_file) {
921 qemu_file_set_rate_limit(s->to_dst_file,
922 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
923 }
924 }
925
926 if (params->has_downtime_limit) {
927 s->parameters.downtime_limit = params->downtime_limit;
928 }
929
930 if (params->has_x_checkpoint_delay) {
931 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay;
932 if (migration_in_colo_state()) {
933 colo_checkpoint_notify(s);
934 }
935 }
936
937 if (params->has_block_incremental) {
938 s->parameters.block_incremental = params->block_incremental;
939 }
940 if (params->has_x_multifd_channels) {
941 s->parameters.x_multifd_channels = params->x_multifd_channels;
942 }
943 if (params->has_x_multifd_page_count) {
944 s->parameters.x_multifd_page_count = params->x_multifd_page_count;
945 }
946 }
947
948 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
949 {
950 MigrationParameters tmp;
951
952 /* TODO Rewrite "" to null instead */
953 if (params->has_tls_creds
954 && params->tls_creds->type == QTYPE_QNULL) {
955 QDECREF(params->tls_creds->u.n);
956 params->tls_creds->type = QTYPE_QSTRING;
957 params->tls_creds->u.s = strdup("");
958 }
959 /* TODO Rewrite "" to null instead */
960 if (params->has_tls_hostname
961 && params->tls_hostname->type == QTYPE_QNULL) {
962 QDECREF(params->tls_hostname->u.n);
963 params->tls_hostname->type = QTYPE_QSTRING;
964 params->tls_hostname->u.s = strdup("");
965 }
966
967 migrate_params_test_apply(params, &tmp);
968
969 if (!migrate_params_check(&tmp, errp)) {
970 /* Invalid parameter */
971 return;
972 }
973
974 migrate_params_apply(params);
975 }
976
977
978 void qmp_migrate_start_postcopy(Error **errp)
979 {
980 MigrationState *s = migrate_get_current();
981
982 if (!migrate_postcopy_ram()) {
983 error_setg(errp, "Enable postcopy with migrate_set_capability before"
984 " the start of migration");
985 return;
986 }
987
988 if (s->state == MIGRATION_STATUS_NONE) {
989 error_setg(errp, "Postcopy must be started after migration has been"
990 " started");
991 return;
992 }
993 /*
994 * we don't error if migration has finished since that would be racy
995 * with issuing this command.
996 */
997 atomic_set(&s->start_postcopy, true);
998 }
999
1000 /* shared migration helpers */
1001
1002 void migrate_set_state(int *state, int old_state, int new_state)
1003 {
1004 assert(new_state < MIGRATION_STATUS__MAX);
1005 if (atomic_cmpxchg(state, old_state, new_state) == old_state) {
1006 trace_migrate_set_state(MigrationStatus_str(new_state));
1007 migrate_generate_event(new_state);
1008 }
1009 }
1010
1011 static MigrationCapabilityStatusList *migrate_cap_add(
1012 MigrationCapabilityStatusList *list,
1013 MigrationCapability index,
1014 bool state)
1015 {
1016 MigrationCapabilityStatusList *cap;
1017
1018 cap = g_new0(MigrationCapabilityStatusList, 1);
1019 cap->value = g_new0(MigrationCapabilityStatus, 1);
1020 cap->value->capability = index;
1021 cap->value->state = state;
1022 cap->next = list;
1023
1024 return cap;
1025 }
1026
1027 void migrate_set_block_enabled(bool value, Error **errp)
1028 {
1029 MigrationCapabilityStatusList *cap;
1030
1031 cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value);
1032 qmp_migrate_set_capabilities(cap, errp);
1033 qapi_free_MigrationCapabilityStatusList(cap);
1034 }
1035
1036 static void migrate_set_block_incremental(MigrationState *s, bool value)
1037 {
1038 s->parameters.block_incremental = value;
1039 }
1040
1041 static void block_cleanup_parameters(MigrationState *s)
1042 {
1043 if (s->must_remove_block_options) {
1044 /* setting to false can never fail */
1045 migrate_set_block_enabled(false, &error_abort);
1046 migrate_set_block_incremental(s, false);
1047 s->must_remove_block_options = false;
1048 }
1049 }
1050
1051 static void migrate_fd_cleanup(void *opaque)
1052 {
1053 MigrationState *s = opaque;
1054
1055 qemu_bh_delete(s->cleanup_bh);
1056 s->cleanup_bh = NULL;
1057
1058 if (s->to_dst_file) {
1059 Error *local_err = NULL;
1060
1061 trace_migrate_fd_cleanup();
1062 qemu_mutex_unlock_iothread();
1063 if (s->migration_thread_running) {
1064 qemu_thread_join(&s->thread);
1065 s->migration_thread_running = false;
1066 }
1067 qemu_mutex_lock_iothread();
1068
1069 if (multifd_save_cleanup(&local_err) != 0) {
1070 error_report_err(local_err);
1071 }
1072 qemu_fclose(s->to_dst_file);
1073 s->to_dst_file = NULL;
1074 }
1075
1076 assert((s->state != MIGRATION_STATUS_ACTIVE) &&
1077 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE));
1078
1079 if (s->state == MIGRATION_STATUS_CANCELLING) {
1080 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
1081 MIGRATION_STATUS_CANCELLED);
1082 }
1083
1084 notifier_list_notify(&migration_state_notifiers, s);
1085 block_cleanup_parameters(s);
1086 }
1087
1088 void migrate_fd_error(MigrationState *s, const Error *error)
1089 {
1090 trace_migrate_fd_error(error_get_pretty(error));
1091 assert(s->to_dst_file == NULL);
1092 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1093 MIGRATION_STATUS_FAILED);
1094 if (!s->error) {
1095 s->error = error_copy(error);
1096 }
1097 notifier_list_notify(&migration_state_notifiers, s);
1098 block_cleanup_parameters(s);
1099 }
1100
1101 static void migrate_fd_cancel(MigrationState *s)
1102 {
1103 int old_state ;
1104 QEMUFile *f = migrate_get_current()->to_dst_file;
1105 trace_migrate_fd_cancel();
1106
1107 if (s->rp_state.from_dst_file) {
1108 /* shutdown the rp socket, so causing the rp thread to shutdown */
1109 qemu_file_shutdown(s->rp_state.from_dst_file);
1110 }
1111
1112 do {
1113 old_state = s->state;
1114 if (!migration_is_setup_or_active(old_state)) {
1115 break;
1116 }
1117 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
1118 } while (s->state != MIGRATION_STATUS_CANCELLING);
1119
1120 /*
1121 * If we're unlucky the migration code might be stuck somewhere in a
1122 * send/write while the network has failed and is waiting to timeout;
1123 * if we've got shutdown(2) available then we can force it to quit.
1124 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1125 * called in a bh, so there is no race against this cancel.
1126 */
1127 if (s->state == MIGRATION_STATUS_CANCELLING && f) {
1128 qemu_file_shutdown(f);
1129 }
1130 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
1131 Error *local_err = NULL;
1132
1133 bdrv_invalidate_cache_all(&local_err);
1134 if (local_err) {
1135 error_report_err(local_err);
1136 } else {
1137 s->block_inactive = false;
1138 }
1139 }
1140 block_cleanup_parameters(s);
1141 }
1142
1143 void add_migration_state_change_notifier(Notifier *notify)
1144 {
1145 notifier_list_add(&migration_state_notifiers, notify);
1146 }
1147
1148 void remove_migration_state_change_notifier(Notifier *notify)
1149 {
1150 notifier_remove(notify);
1151 }
1152
1153 bool migration_in_setup(MigrationState *s)
1154 {
1155 return s->state == MIGRATION_STATUS_SETUP;
1156 }
1157
1158 bool migration_has_finished(MigrationState *s)
1159 {
1160 return s->state == MIGRATION_STATUS_COMPLETED;
1161 }
1162
1163 bool migration_has_failed(MigrationState *s)
1164 {
1165 return (s->state == MIGRATION_STATUS_CANCELLED ||
1166 s->state == MIGRATION_STATUS_FAILED);
1167 }
1168
1169 bool migration_in_postcopy(void)
1170 {
1171 MigrationState *s = migrate_get_current();
1172
1173 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
1174 }
1175
1176 bool migration_in_postcopy_after_devices(MigrationState *s)
1177 {
1178 return migration_in_postcopy() && s->postcopy_after_devices;
1179 }
1180
1181 bool migration_is_idle(void)
1182 {
1183 MigrationState *s = migrate_get_current();
1184
1185 switch (s->state) {
1186 case MIGRATION_STATUS_NONE:
1187 case MIGRATION_STATUS_CANCELLED:
1188 case MIGRATION_STATUS_COMPLETED:
1189 case MIGRATION_STATUS_FAILED:
1190 return true;
1191 case MIGRATION_STATUS_SETUP:
1192 case MIGRATION_STATUS_CANCELLING:
1193 case MIGRATION_STATUS_ACTIVE:
1194 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1195 case MIGRATION_STATUS_COLO:
1196 case MIGRATION_STATUS_PRE_SWITCHOVER:
1197 case MIGRATION_STATUS_DEVICE:
1198 return false;
1199 case MIGRATION_STATUS__MAX:
1200 g_assert_not_reached();
1201 }
1202
1203 return false;
1204 }
1205
1206 MigrationState *migrate_init(void)
1207 {
1208 MigrationState *s = migrate_get_current();
1209
1210 /*
1211 * Reinitialise all migration state, except
1212 * parameters/capabilities that the user set, and
1213 * locks.
1214 */
1215 s->bytes_xfer = 0;
1216 s->xfer_limit = 0;
1217 s->cleanup_bh = 0;
1218 s->to_dst_file = NULL;
1219 s->state = MIGRATION_STATUS_NONE;
1220 s->rp_state.from_dst_file = NULL;
1221 s->rp_state.error = false;
1222 s->mbps = 0.0;
1223 s->downtime = 0;
1224 s->expected_downtime = 0;
1225 s->setup_time = 0;
1226 s->start_postcopy = false;
1227 s->postcopy_after_devices = false;
1228 s->migration_thread_running = false;
1229 error_free(s->error);
1230 s->error = NULL;
1231
1232 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
1233
1234 s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1235 return s;
1236 }
1237
1238 static GSList *migration_blockers;
1239
1240 int migrate_add_blocker(Error *reason, Error **errp)
1241 {
1242 if (migrate_get_current()->only_migratable) {
1243 error_propagate(errp, error_copy(reason));
1244 error_prepend(errp, "disallowing migration blocker "
1245 "(--only_migratable) for: ");
1246 return -EACCES;
1247 }
1248
1249 if (migration_is_idle()) {
1250 migration_blockers = g_slist_prepend(migration_blockers, reason);
1251 return 0;
1252 }
1253
1254 error_propagate(errp, error_copy(reason));
1255 error_prepend(errp, "disallowing migration blocker (migration in "
1256 "progress) for: ");
1257 return -EBUSY;
1258 }
1259
1260 void migrate_del_blocker(Error *reason)
1261 {
1262 migration_blockers = g_slist_remove(migration_blockers, reason);
1263 }
1264
1265 void qmp_migrate_incoming(const char *uri, Error **errp)
1266 {
1267 Error *local_err = NULL;
1268 static bool once = true;
1269
1270 if (!deferred_incoming) {
1271 error_setg(errp, "For use with '-incoming defer'");
1272 return;
1273 }
1274 if (!once) {
1275 error_setg(errp, "The incoming migration has already been started");
1276 }
1277
1278 qemu_start_incoming_migration(uri, &local_err);
1279
1280 if (local_err) {
1281 error_propagate(errp, local_err);
1282 return;
1283 }
1284
1285 once = false;
1286 }
1287
1288 bool migration_is_blocked(Error **errp)
1289 {
1290 if (qemu_savevm_state_blocked(errp)) {
1291 return true;
1292 }
1293
1294 if (migration_blockers) {
1295 error_propagate(errp, error_copy(migration_blockers->data));
1296 return true;
1297 }
1298
1299 return false;
1300 }
1301
1302 void qmp_migrate(const char *uri, bool has_blk, bool blk,
1303 bool has_inc, bool inc, bool has_detach, bool detach,
1304 Error **errp)
1305 {
1306 Error *local_err = NULL;
1307 MigrationState *s = migrate_get_current();
1308 const char *p;
1309
1310 if (migration_is_setup_or_active(s->state) ||
1311 s->state == MIGRATION_STATUS_CANCELLING ||
1312 s->state == MIGRATION_STATUS_COLO) {
1313 error_setg(errp, QERR_MIGRATION_ACTIVE);
1314 return;
1315 }
1316 if (runstate_check(RUN_STATE_INMIGRATE)) {
1317 error_setg(errp, "Guest is waiting for an incoming migration");
1318 return;
1319 }
1320
1321 if (migration_is_blocked(errp)) {
1322 return;
1323 }
1324
1325 if ((has_blk && blk) || (has_inc && inc)) {
1326 if (migrate_use_block() || migrate_use_block_incremental()) {
1327 error_setg(errp, "Command options are incompatible with "
1328 "current migration capabilities");
1329 return;
1330 }
1331 migrate_set_block_enabled(true, &local_err);
1332 if (local_err) {
1333 error_propagate(errp, local_err);
1334 return;
1335 }
1336 s->must_remove_block_options = true;
1337 }
1338
1339 if (has_inc && inc) {
1340 migrate_set_block_incremental(s, true);
1341 }
1342
1343 s = migrate_init();
1344
1345 if (strstart(uri, "tcp:", &p)) {
1346 tcp_start_outgoing_migration(s, p, &local_err);
1347 #ifdef CONFIG_RDMA
1348 } else if (strstart(uri, "rdma:", &p)) {
1349 rdma_start_outgoing_migration(s, p, &local_err);
1350 #endif
1351 } else if (strstart(uri, "exec:", &p)) {
1352 exec_start_outgoing_migration(s, p, &local_err);
1353 } else if (strstart(uri, "unix:", &p)) {
1354 unix_start_outgoing_migration(s, p, &local_err);
1355 } else if (strstart(uri, "fd:", &p)) {
1356 fd_start_outgoing_migration(s, p, &local_err);
1357 } else {
1358 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
1359 "a valid migration protocol");
1360 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1361 MIGRATION_STATUS_FAILED);
1362 return;
1363 }
1364
1365 if (local_err) {
1366 migrate_fd_error(s, local_err);
1367 error_propagate(errp, local_err);
1368 return;
1369 }
1370 }
1371
1372 void qmp_migrate_cancel(Error **errp)
1373 {
1374 migrate_fd_cancel(migrate_get_current());
1375 }
1376
1377 void qmp_migrate_continue(MigrationStatus state, Error **errp)
1378 {
1379 MigrationState *s = migrate_get_current();
1380 if (s->state != state) {
1381 error_setg(errp, "Migration not in expected state: %s",
1382 MigrationStatus_str(s->state));
1383 return;
1384 }
1385 qemu_sem_post(&s->pause_sem);
1386 }
1387
1388 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
1389 {
1390 MigrationState *s = migrate_get_current();
1391 int64_t new_size;
1392
1393 new_size = xbzrle_cache_resize(value, errp);
1394 if (new_size < 0) {
1395 return;
1396 }
1397
1398 s->xbzrle_cache_size = new_size;
1399 }
1400
1401 int64_t qmp_query_migrate_cache_size(Error **errp)
1402 {
1403 return migrate_xbzrle_cache_size();
1404 }
1405
1406 void qmp_migrate_set_speed(int64_t value, Error **errp)
1407 {
1408 MigrateSetParameters p = {
1409 .has_max_bandwidth = true,
1410 .max_bandwidth = value,
1411 };
1412
1413 qmp_migrate_set_parameters(&p, errp);
1414 }
1415
1416 void qmp_migrate_set_downtime(double value, Error **errp)
1417 {
1418 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) {
1419 error_setg(errp, "Parameter 'downtime_limit' expects an integer in "
1420 "the range of 0 to %d seconds",
1421 MAX_MIGRATE_DOWNTIME_SECONDS);
1422 return;
1423 }
1424
1425 value *= 1000; /* Convert to milliseconds */
1426 value = MAX(0, MIN(INT64_MAX, value));
1427
1428 MigrateSetParameters p = {
1429 .has_downtime_limit = true,
1430 .downtime_limit = value,
1431 };
1432
1433 qmp_migrate_set_parameters(&p, errp);
1434 }
1435
1436 bool migrate_release_ram(void)
1437 {
1438 MigrationState *s;
1439
1440 s = migrate_get_current();
1441
1442 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM];
1443 }
1444
1445 bool migrate_postcopy_ram(void)
1446 {
1447 MigrationState *s;
1448
1449 s = migrate_get_current();
1450
1451 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM];
1452 }
1453
1454 bool migrate_postcopy(void)
1455 {
1456 return migrate_postcopy_ram();
1457 }
1458
1459 bool migrate_auto_converge(void)
1460 {
1461 MigrationState *s;
1462
1463 s = migrate_get_current();
1464
1465 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
1466 }
1467
1468 bool migrate_zero_blocks(void)
1469 {
1470 MigrationState *s;
1471
1472 s = migrate_get_current();
1473
1474 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
1475 }
1476
1477 bool migrate_use_compression(void)
1478 {
1479 MigrationState *s;
1480
1481 s = migrate_get_current();
1482
1483 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
1484 }
1485
1486 int migrate_compress_level(void)
1487 {
1488 MigrationState *s;
1489
1490 s = migrate_get_current();
1491
1492 return s->parameters.compress_level;
1493 }
1494
1495 int migrate_compress_threads(void)
1496 {
1497 MigrationState *s;
1498
1499 s = migrate_get_current();
1500
1501 return s->parameters.compress_threads;
1502 }
1503
1504 int migrate_decompress_threads(void)
1505 {
1506 MigrationState *s;
1507
1508 s = migrate_get_current();
1509
1510 return s->parameters.decompress_threads;
1511 }
1512
1513 bool migrate_use_events(void)
1514 {
1515 MigrationState *s;
1516
1517 s = migrate_get_current();
1518
1519 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
1520 }
1521
1522 bool migrate_use_multifd(void)
1523 {
1524 MigrationState *s;
1525
1526 s = migrate_get_current();
1527
1528 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD];
1529 }
1530
1531 bool migrate_pause_before_switchover(void)
1532 {
1533 MigrationState *s;
1534
1535 s = migrate_get_current();
1536
1537 return s->enabled_capabilities[
1538 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
1539 }
1540
1541 int migrate_multifd_channels(void)
1542 {
1543 MigrationState *s;
1544
1545 s = migrate_get_current();
1546
1547 return s->parameters.x_multifd_channels;
1548 }
1549
1550 int migrate_multifd_page_count(void)
1551 {
1552 MigrationState *s;
1553
1554 s = migrate_get_current();
1555
1556 return s->parameters.x_multifd_page_count;
1557 }
1558
1559 int migrate_use_xbzrle(void)
1560 {
1561 MigrationState *s;
1562
1563 s = migrate_get_current();
1564
1565 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
1566 }
1567
1568 int64_t migrate_xbzrle_cache_size(void)
1569 {
1570 MigrationState *s;
1571
1572 s = migrate_get_current();
1573
1574 return s->xbzrle_cache_size;
1575 }
1576
1577 bool migrate_use_block(void)
1578 {
1579 MigrationState *s;
1580
1581 s = migrate_get_current();
1582
1583 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK];
1584 }
1585
1586 bool migrate_use_return_path(void)
1587 {
1588 MigrationState *s;
1589
1590 s = migrate_get_current();
1591
1592 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH];
1593 }
1594
1595 bool migrate_use_block_incremental(void)
1596 {
1597 MigrationState *s;
1598
1599 s = migrate_get_current();
1600
1601 return s->parameters.block_incremental;
1602 }
1603
1604 /* migration thread support */
1605 /*
1606 * Something bad happened to the RP stream, mark an error
1607 * The caller shall print or trace something to indicate why
1608 */
1609 static void mark_source_rp_bad(MigrationState *s)
1610 {
1611 s->rp_state.error = true;
1612 }
1613
1614 static struct rp_cmd_args {
1615 ssize_t len; /* -1 = variable */
1616 const char *name;
1617 } rp_cmd_args[] = {
1618 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
1619 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
1620 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
1621 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
1622 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
1623 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
1624 };
1625
1626 /*
1627 * Process a request for pages received on the return path,
1628 * We're allowed to send more than requested (e.g. to round to our page size)
1629 * and we don't need to send pages that have already been sent.
1630 */
1631 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
1632 ram_addr_t start, size_t len)
1633 {
1634 long our_host_ps = getpagesize();
1635
1636 trace_migrate_handle_rp_req_pages(rbname, start, len);
1637
1638 /*
1639 * Since we currently insist on matching page sizes, just sanity check
1640 * we're being asked for whole host pages.
1641 */
1642 if (start & (our_host_ps-1) ||
1643 (len & (our_host_ps-1))) {
1644 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
1645 " len: %zd", __func__, start, len);
1646 mark_source_rp_bad(ms);
1647 return;
1648 }
1649
1650 if (ram_save_queue_pages(rbname, start, len)) {
1651 mark_source_rp_bad(ms);
1652 }
1653 }
1654
1655 /*
1656 * Handles messages sent on the return path towards the source VM
1657 *
1658 */
1659 static void *source_return_path_thread(void *opaque)
1660 {
1661 MigrationState *ms = opaque;
1662 QEMUFile *rp = ms->rp_state.from_dst_file;
1663 uint16_t header_len, header_type;
1664 uint8_t buf[512];
1665 uint32_t tmp32, sibling_error;
1666 ram_addr_t start = 0; /* =0 to silence warning */
1667 size_t len = 0, expected_len;
1668 int res;
1669
1670 trace_source_return_path_thread_entry();
1671 while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
1672 migration_is_setup_or_active(ms->state)) {
1673 trace_source_return_path_thread_loop_top();
1674 header_type = qemu_get_be16(rp);
1675 header_len = qemu_get_be16(rp);
1676
1677 if (header_type >= MIG_RP_MSG_MAX ||
1678 header_type == MIG_RP_MSG_INVALID) {
1679 error_report("RP: Received invalid message 0x%04x length 0x%04x",
1680 header_type, header_len);
1681 mark_source_rp_bad(ms);
1682 goto out;
1683 }
1684
1685 if ((rp_cmd_args[header_type].len != -1 &&
1686 header_len != rp_cmd_args[header_type].len) ||
1687 header_len > sizeof(buf)) {
1688 error_report("RP: Received '%s' message (0x%04x) with"
1689 "incorrect length %d expecting %zu",
1690 rp_cmd_args[header_type].name, header_type, header_len,
1691 (size_t)rp_cmd_args[header_type].len);
1692 mark_source_rp_bad(ms);
1693 goto out;
1694 }
1695
1696 /* We know we've got a valid header by this point */
1697 res = qemu_get_buffer(rp, buf, header_len);
1698 if (res != header_len) {
1699 error_report("RP: Failed reading data for message 0x%04x"
1700 " read %d expected %d",
1701 header_type, res, header_len);
1702 mark_source_rp_bad(ms);
1703 goto out;
1704 }
1705
1706 /* OK, we have the message and the data */
1707 switch (header_type) {
1708 case MIG_RP_MSG_SHUT:
1709 sibling_error = ldl_be_p(buf);
1710 trace_source_return_path_thread_shut(sibling_error);
1711 if (sibling_error) {
1712 error_report("RP: Sibling indicated error %d", sibling_error);
1713 mark_source_rp_bad(ms);
1714 }
1715 /*
1716 * We'll let the main thread deal with closing the RP
1717 * we could do a shutdown(2) on it, but we're the only user
1718 * anyway, so there's nothing gained.
1719 */
1720 goto out;
1721
1722 case MIG_RP_MSG_PONG:
1723 tmp32 = ldl_be_p(buf);
1724 trace_source_return_path_thread_pong(tmp32);
1725 break;
1726
1727 case MIG_RP_MSG_REQ_PAGES:
1728 start = ldq_be_p(buf);
1729 len = ldl_be_p(buf + 8);
1730 migrate_handle_rp_req_pages(ms, NULL, start, len);
1731 break;
1732
1733 case MIG_RP_MSG_REQ_PAGES_ID:
1734 expected_len = 12 + 1; /* header + termination */
1735
1736 if (header_len >= expected_len) {
1737 start = ldq_be_p(buf);
1738 len = ldl_be_p(buf + 8);
1739 /* Now we expect an idstr */
1740 tmp32 = buf[12]; /* Length of the following idstr */
1741 buf[13 + tmp32] = '\0';
1742 expected_len += tmp32;
1743 }
1744 if (header_len != expected_len) {
1745 error_report("RP: Req_Page_id with length %d expecting %zd",
1746 header_len, expected_len);
1747 mark_source_rp_bad(ms);
1748 goto out;
1749 }
1750 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
1751 break;
1752
1753 default:
1754 break;
1755 }
1756 }
1757 if (qemu_file_get_error(rp)) {
1758 trace_source_return_path_thread_bad_end();
1759 mark_source_rp_bad(ms);
1760 }
1761
1762 trace_source_return_path_thread_end();
1763 out:
1764 ms->rp_state.from_dst_file = NULL;
1765 qemu_fclose(rp);
1766 return NULL;
1767 }
1768
1769 static int open_return_path_on_source(MigrationState *ms)
1770 {
1771
1772 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
1773 if (!ms->rp_state.from_dst_file) {
1774 return -1;
1775 }
1776
1777 trace_open_return_path_on_source();
1778 qemu_thread_create(&ms->rp_state.rp_thread, "return path",
1779 source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
1780
1781 trace_open_return_path_on_source_continue();
1782
1783 return 0;
1784 }
1785
1786 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1787 static int await_return_path_close_on_source(MigrationState *ms)
1788 {
1789 /*
1790 * If this is a normal exit then the destination will send a SHUT and the
1791 * rp_thread will exit, however if there's an error we need to cause
1792 * it to exit.
1793 */
1794 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) {
1795 /*
1796 * shutdown(2), if we have it, will cause it to unblock if it's stuck
1797 * waiting for the destination.
1798 */
1799 qemu_file_shutdown(ms->rp_state.from_dst_file);
1800 mark_source_rp_bad(ms);
1801 }
1802 trace_await_return_path_close_on_source_joining();
1803 qemu_thread_join(&ms->rp_state.rp_thread);
1804 trace_await_return_path_close_on_source_close();
1805 return ms->rp_state.error;
1806 }
1807
1808 /*
1809 * Switch from normal iteration to postcopy
1810 * Returns non-0 on error
1811 */
1812 static int postcopy_start(MigrationState *ms, bool *old_vm_running)
1813 {
1814 int ret;
1815 QIOChannelBuffer *bioc;
1816 QEMUFile *fb;
1817 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1818 bool restart_block = false;
1819 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
1820 MIGRATION_STATUS_POSTCOPY_ACTIVE);
1821
1822 trace_postcopy_start();
1823 qemu_mutex_lock_iothread();
1824 trace_postcopy_start_set_run();
1825
1826 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
1827 *old_vm_running = runstate_is_running();
1828 global_state_store();
1829 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
1830 if (ret < 0) {
1831 goto fail;
1832 }
1833
1834 ret = bdrv_inactivate_all();
1835 if (ret < 0) {
1836 goto fail;
1837 }
1838 restart_block = true;
1839
1840 /*
1841 * Cause any non-postcopiable, but iterative devices to
1842 * send out their final data.
1843 */
1844 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false);
1845
1846 /*
1847 * in Finish migrate and with the io-lock held everything should
1848 * be quiet, but we've potentially still got dirty pages and we
1849 * need to tell the destination to throw any pages it's already received
1850 * that are dirty
1851 */
1852 if (migrate_postcopy_ram()) {
1853 if (ram_postcopy_send_discard_bitmap(ms)) {
1854 error_report("postcopy send discard bitmap failed");
1855 goto fail;
1856 }
1857 }
1858
1859 /*
1860 * send rest of state - note things that are doing postcopy
1861 * will notice we're in POSTCOPY_ACTIVE and not actually
1862 * wrap their state up here
1863 */
1864 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);
1865 if (migrate_postcopy_ram()) {
1866 /* Ping just for debugging, helps line traces up */
1867 qemu_savevm_send_ping(ms->to_dst_file, 2);
1868 }
1869
1870 /*
1871 * While loading the device state we may trigger page transfer
1872 * requests and the fd must be free to process those, and thus
1873 * the destination must read the whole device state off the fd before
1874 * it starts processing it. Unfortunately the ad-hoc migration format
1875 * doesn't allow the destination to know the size to read without fully
1876 * parsing it through each devices load-state code (especially the open
1877 * coded devices that use get/put).
1878 * So we wrap the device state up in a package with a length at the start;
1879 * to do this we use a qemu_buf to hold the whole of the device state.
1880 */
1881 bioc = qio_channel_buffer_new(4096);
1882 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");
1883 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
1884 object_unref(OBJECT(bioc));
1885
1886 /*
1887 * Make sure the receiver can get incoming pages before we send the rest
1888 * of the state
1889 */
1890 qemu_savevm_send_postcopy_listen(fb);
1891
1892 qemu_savevm_state_complete_precopy(fb, false, false);
1893 if (migrate_postcopy_ram()) {
1894 qemu_savevm_send_ping(fb, 3);
1895 }
1896
1897 qemu_savevm_send_postcopy_run(fb);
1898
1899 /* <><> end of stuff going into the package */
1900
1901 /* Last point of recovery; as soon as we send the package the destination
1902 * can open devices and potentially start running.
1903 * Lets just check again we've not got any errors.
1904 */
1905 ret = qemu_file_get_error(ms->to_dst_file);
1906 if (ret) {
1907 error_report("postcopy_start: Migration stream errored (pre package)");
1908 goto fail_closefb;
1909 }
1910
1911 restart_block = false;
1912
1913 /* Now send that blob */
1914 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) {
1915 goto fail_closefb;
1916 }
1917 qemu_fclose(fb);
1918
1919 /* Send a notify to give a chance for anything that needs to happen
1920 * at the transition to postcopy and after the device state; in particular
1921 * spice needs to trigger a transition now
1922 */
1923 ms->postcopy_after_devices = true;
1924 notifier_list_notify(&migration_state_notifiers, ms);
1925
1926 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
1927
1928 qemu_mutex_unlock_iothread();
1929
1930 if (migrate_postcopy_ram()) {
1931 /*
1932 * Although this ping is just for debug, it could potentially be
1933 * used for getting a better measurement of downtime at the source.
1934 */
1935 qemu_savevm_send_ping(ms->to_dst_file, 4);
1936 }
1937
1938 if (migrate_release_ram()) {
1939 ram_postcopy_migrated_memory_release(ms);
1940 }
1941
1942 ret = qemu_file_get_error(ms->to_dst_file);
1943 if (ret) {
1944 error_report("postcopy_start: Migration stream errored");
1945 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1946 MIGRATION_STATUS_FAILED);
1947 }
1948
1949 return ret;
1950
1951 fail_closefb:
1952 qemu_fclose(fb);
1953 fail:
1954 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1955 MIGRATION_STATUS_FAILED);
1956 if (restart_block) {
1957 /* A failure happened early enough that we know the destination hasn't
1958 * accessed block devices, so we're safe to recover.
1959 */
1960 Error *local_err = NULL;
1961
1962 bdrv_invalidate_cache_all(&local_err);
1963 if (local_err) {
1964 error_report_err(local_err);
1965 }
1966 }
1967 qemu_mutex_unlock_iothread();
1968 return -1;
1969 }
1970
1971 /**
1972 * migration_maybe_pause: Pause if required to by
1973 * migrate_pause_before_switchover called with the iothread locked
1974 * Returns: 0 on success
1975 */
1976 static int migration_maybe_pause(MigrationState *s, int *current_active_state)
1977 {
1978 if (!migrate_pause_before_switchover()) {
1979 return 0;
1980 }
1981
1982 /* Since leaving this state is not atomic with posting the semaphore
1983 * it's possible that someone could have issued multiple migrate_continue
1984 * and the semaphore is incorrectly positive at this point;
1985 * the docs say it's undefined to reinit a semaphore that's already
1986 * init'd, so use timedwait to eat up any existing posts.
1987 */
1988 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
1989 /* This block intentionally left blank */
1990 }
1991
1992 qemu_mutex_unlock_iothread();
1993 migrate_set_state(&s->state, *current_active_state,
1994 MIGRATION_STATUS_PRE_SWITCHOVER);
1995 qemu_sem_wait(&s->pause_sem);
1996 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
1997 MIGRATION_STATUS_DEVICE);
1998 *current_active_state = MIGRATION_STATUS_DEVICE;
1999 qemu_mutex_lock_iothread();
2000
2001 return s->state == MIGRATION_STATUS_DEVICE ? 0 : -EINVAL;
2002 }
2003
2004 /**
2005 * migration_completion: Used by migration_thread when there's not much left.
2006 * The caller 'breaks' the loop when this returns.
2007 *
2008 * @s: Current migration state
2009 * @current_active_state: The migration state we expect to be in
2010 * @*old_vm_running: Pointer to old_vm_running flag
2011 * @*start_time: Pointer to time to update
2012 */
2013 static void migration_completion(MigrationState *s, int current_active_state,
2014 bool *old_vm_running,
2015 int64_t *start_time)
2016 {
2017 int ret;
2018
2019 if (s->state == MIGRATION_STATUS_ACTIVE) {
2020 qemu_mutex_lock_iothread();
2021 *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2022 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
2023 *old_vm_running = runstate_is_running();
2024 ret = global_state_store();
2025
2026 if (!ret) {
2027 bool inactivate = !migrate_colo_enabled();
2028 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2029 if (ret >= 0) {
2030 ret = migration_maybe_pause(s, &current_active_state);
2031 }
2032 if (ret >= 0) {
2033 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
2034 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
2035 inactivate);
2036 }
2037 if (inactivate && ret >= 0) {
2038 s->block_inactive = true;
2039 }
2040 }
2041 qemu_mutex_unlock_iothread();
2042
2043 if (ret < 0) {
2044 goto fail;
2045 }
2046 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2047 trace_migration_completion_postcopy_end();
2048
2049 qemu_savevm_state_complete_postcopy(s->to_dst_file);
2050 trace_migration_completion_postcopy_end_after_complete();
2051 }
2052
2053 /*
2054 * If rp was opened we must clean up the thread before
2055 * cleaning everything else up (since if there are no failures
2056 * it will wait for the destination to send it's status in
2057 * a SHUT command).
2058 */
2059 if (s->rp_state.from_dst_file) {
2060 int rp_error;
2061 trace_migration_return_path_end_before();
2062 rp_error = await_return_path_close_on_source(s);
2063 trace_migration_return_path_end_after(rp_error);
2064 if (rp_error) {
2065 goto fail_invalidate;
2066 }
2067 }
2068
2069 if (qemu_file_get_error(s->to_dst_file)) {
2070 trace_migration_completion_file_err();
2071 goto fail_invalidate;
2072 }
2073
2074 if (!migrate_colo_enabled()) {
2075 migrate_set_state(&s->state, current_active_state,
2076 MIGRATION_STATUS_COMPLETED);
2077 }
2078
2079 return;
2080
2081 fail_invalidate:
2082 /* If not doing postcopy, vm_start() will be called: let's regain
2083 * control on images.
2084 */
2085 if (s->state == MIGRATION_STATUS_ACTIVE) {
2086 Error *local_err = NULL;
2087
2088 qemu_mutex_lock_iothread();
2089 bdrv_invalidate_cache_all(&local_err);
2090 if (local_err) {
2091 error_report_err(local_err);
2092 } else {
2093 s->block_inactive = false;
2094 }
2095 qemu_mutex_unlock_iothread();
2096 }
2097
2098 fail:
2099 migrate_set_state(&s->state, current_active_state,
2100 MIGRATION_STATUS_FAILED);
2101 }
2102
2103 bool migrate_colo_enabled(void)
2104 {
2105 MigrationState *s = migrate_get_current();
2106 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
2107 }
2108
2109 /*
2110 * Master migration thread on the source VM.
2111 * It drives the migration and pumps the data down the outgoing channel.
2112 */
2113 static void *migration_thread(void *opaque)
2114 {
2115 MigrationState *s = opaque;
2116 /* Used by the bandwidth calcs, updated later */
2117 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2118 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
2119 int64_t initial_bytes = 0;
2120 /*
2121 * The final stage happens when the remaining data is smaller than
2122 * this threshold; it's calculated from the requested downtime and
2123 * measured bandwidth
2124 */
2125 int64_t threshold_size = 0;
2126 int64_t start_time = initial_time;
2127 int64_t end_time;
2128 bool old_vm_running = false;
2129 bool entered_postcopy = false;
2130 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
2131 enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
2132 bool enable_colo = migrate_colo_enabled();
2133
2134 rcu_register_thread();
2135
2136 qemu_savevm_state_header(s->to_dst_file);
2137
2138 /*
2139 * If we opened the return path, we need to make sure dst has it
2140 * opened as well.
2141 */
2142 if (s->rp_state.from_dst_file) {
2143 /* Now tell the dest that it should open its end so it can reply */
2144 qemu_savevm_send_open_return_path(s->to_dst_file);
2145
2146 /* And do a ping that will make stuff easier to debug */
2147 qemu_savevm_send_ping(s->to_dst_file, 1);
2148 }
2149
2150 if (migrate_postcopy()) {
2151 /*
2152 * Tell the destination that we *might* want to do postcopy later;
2153 * if the other end can't do postcopy it should fail now, nice and
2154 * early.
2155 */
2156 qemu_savevm_send_postcopy_advise(s->to_dst_file);
2157 }
2158
2159 qemu_savevm_state_setup(s->to_dst_file);
2160
2161 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
2162 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2163 MIGRATION_STATUS_ACTIVE);
2164
2165 trace_migration_thread_setup_complete();
2166
2167 while (s->state == MIGRATION_STATUS_ACTIVE ||
2168 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2169 int64_t current_time;
2170 uint64_t pending_size;
2171
2172 if (!qemu_file_rate_limit(s->to_dst_file)) {
2173 uint64_t pend_post, pend_nonpost;
2174
2175 qemu_savevm_state_pending(s->to_dst_file, threshold_size,
2176 &pend_nonpost, &pend_post);
2177 pending_size = pend_nonpost + pend_post;
2178 trace_migrate_pending(pending_size, threshold_size,
2179 pend_post, pend_nonpost);
2180 if (pending_size && pending_size >= threshold_size) {
2181 /* Still a significant amount to transfer */
2182
2183 if (migrate_postcopy() &&
2184 s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE &&
2185 pend_nonpost <= threshold_size &&
2186 atomic_read(&s->start_postcopy)) {
2187
2188 if (!postcopy_start(s, &old_vm_running)) {
2189 current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE;
2190 entered_postcopy = true;
2191 }
2192
2193 continue;
2194 }
2195 /* Just another iteration step */
2196 qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy);
2197 } else {
2198 trace_migration_thread_low_pending(pending_size);
2199 migration_completion(s, current_active_state,
2200 &old_vm_running, &start_time);
2201 break;
2202 }
2203 }
2204
2205 if (qemu_file_get_error(s->to_dst_file)) {
2206 migrate_set_state(&s->state, current_active_state,
2207 MIGRATION_STATUS_FAILED);
2208 trace_migration_thread_file_err();
2209 break;
2210 }
2211 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2212 if (current_time >= initial_time + BUFFER_DELAY) {
2213 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file) -
2214 initial_bytes;
2215 uint64_t time_spent = current_time - initial_time;
2216 double bandwidth = (double)transferred_bytes / time_spent;
2217 threshold_size = bandwidth * s->parameters.downtime_limit;
2218
2219 s->mbps = (((double) transferred_bytes * 8.0) /
2220 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
2221
2222 trace_migrate_transferred(transferred_bytes, time_spent,
2223 bandwidth, threshold_size);
2224 /* if we haven't sent anything, we don't want to recalculate
2225 10000 is a small enough number for our purposes */
2226 if (ram_counters.dirty_pages_rate && transferred_bytes > 10000) {
2227 s->expected_downtime = ram_counters.dirty_pages_rate *
2228 qemu_target_page_size() / bandwidth;
2229 }
2230
2231 qemu_file_reset_rate_limit(s->to_dst_file);
2232 initial_time = current_time;
2233 initial_bytes = qemu_ftell(s->to_dst_file);
2234 }
2235 if (qemu_file_rate_limit(s->to_dst_file)) {
2236 /* usleep expects microseconds */
2237 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
2238 }
2239 }
2240
2241 trace_migration_thread_after_loop();
2242 /* If we enabled cpu throttling for auto-converge, turn it off. */
2243 cpu_throttle_stop();
2244 end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2245
2246 qemu_mutex_lock_iothread();
2247 /*
2248 * The resource has been allocated by migration will be reused in COLO
2249 * process, so don't release them.
2250 */
2251 if (!enable_colo) {
2252 qemu_savevm_state_cleanup();
2253 }
2254 if (s->state == MIGRATION_STATUS_COMPLETED) {
2255 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file);
2256 s->total_time = end_time - s->total_time;
2257 if (!entered_postcopy) {
2258 s->downtime = end_time - start_time;
2259 }
2260 if (s->total_time) {
2261 s->mbps = (((double) transferred_bytes * 8.0) /
2262 ((double) s->total_time)) / 1000;
2263 }
2264 runstate_set(RUN_STATE_POSTMIGRATE);
2265 } else {
2266 if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) {
2267 migrate_start_colo_process(s);
2268 qemu_savevm_state_cleanup();
2269 /*
2270 * Fixme: we will run VM in COLO no matter its old running state.
2271 * After exited COLO, we will keep running.
2272 */
2273 old_vm_running = true;
2274 }
2275 if (old_vm_running && !entered_postcopy) {
2276 vm_start();
2277 } else {
2278 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
2279 runstate_set(RUN_STATE_POSTMIGRATE);
2280 }
2281 }
2282 }
2283 qemu_bh_schedule(s->cleanup_bh);
2284 qemu_mutex_unlock_iothread();
2285
2286 rcu_unregister_thread();
2287 return NULL;
2288 }
2289
2290 void migrate_fd_connect(MigrationState *s)
2291 {
2292 s->expected_downtime = s->parameters.downtime_limit;
2293 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
2294
2295 qemu_file_set_blocking(s->to_dst_file, true);
2296 qemu_file_set_rate_limit(s->to_dst_file,
2297 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
2298
2299 /* Notify before starting migration thread */
2300 notifier_list_notify(&migration_state_notifiers, s);
2301
2302 /*
2303 * Open the return path. For postcopy, it is used exclusively. For
2304 * precopy, only if user specified "return-path" capability would
2305 * QEMU uses the return path.
2306 */
2307 if (migrate_postcopy_ram() || migrate_use_return_path()) {
2308 if (open_return_path_on_source(s)) {
2309 error_report("Unable to open return-path for postcopy");
2310 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2311 MIGRATION_STATUS_FAILED);
2312 migrate_fd_cleanup(s);
2313 return;
2314 }
2315 }
2316
2317 if (multifd_save_setup() != 0) {
2318 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2319 MIGRATION_STATUS_FAILED);
2320 migrate_fd_cleanup(s);
2321 return;
2322 }
2323 qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
2324 QEMU_THREAD_JOINABLE);
2325 s->migration_thread_running = true;
2326 }
2327
2328 void migration_global_dump(Monitor *mon)
2329 {
2330 MigrationState *ms = migrate_get_current();
2331
2332 monitor_printf(mon, "globals: store-global-state=%d, only_migratable=%d, "
2333 "send-configuration=%d, send-section-footer=%d\n",
2334 ms->store_global_state, ms->only_migratable,
2335 ms->send_configuration, ms->send_section_footer);
2336 }
2337
2338 #define DEFINE_PROP_MIG_CAP(name, x) \
2339 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false)
2340
2341 static Property migration_properties[] = {
2342 DEFINE_PROP_BOOL("store-global-state", MigrationState,
2343 store_global_state, true),
2344 DEFINE_PROP_BOOL("only-migratable", MigrationState, only_migratable, false),
2345 DEFINE_PROP_BOOL("send-configuration", MigrationState,
2346 send_configuration, true),
2347 DEFINE_PROP_BOOL("send-section-footer", MigrationState,
2348 send_section_footer, true),
2349
2350 /* Migration parameters */
2351 DEFINE_PROP_INT64("x-compress-level", MigrationState,
2352 parameters.compress_level,
2353 DEFAULT_MIGRATE_COMPRESS_LEVEL),
2354 DEFINE_PROP_INT64("x-compress-threads", MigrationState,
2355 parameters.compress_threads,
2356 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT),
2357 DEFINE_PROP_INT64("x-decompress-threads", MigrationState,
2358 parameters.decompress_threads,
2359 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT),
2360 DEFINE_PROP_INT64("x-cpu-throttle-initial", MigrationState,
2361 parameters.cpu_throttle_initial,
2362 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL),
2363 DEFINE_PROP_INT64("x-cpu-throttle-increment", MigrationState,
2364 parameters.cpu_throttle_increment,
2365 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT),
2366 DEFINE_PROP_INT64("x-max-bandwidth", MigrationState,
2367 parameters.max_bandwidth, MAX_THROTTLE),
2368 DEFINE_PROP_INT64("x-downtime-limit", MigrationState,
2369 parameters.downtime_limit,
2370 DEFAULT_MIGRATE_SET_DOWNTIME),
2371 DEFINE_PROP_INT64("x-checkpoint-delay", MigrationState,
2372 parameters.x_checkpoint_delay,
2373 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY),
2374 DEFINE_PROP_INT64("x-multifd-channels", MigrationState,
2375 parameters.x_multifd_channels,
2376 DEFAULT_MIGRATE_MULTIFD_CHANNELS),
2377 DEFINE_PROP_INT64("x-multifd-page-count", MigrationState,
2378 parameters.x_multifd_page_count,
2379 DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT),
2380
2381 /* Migration capabilities */
2382 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
2383 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL),
2384 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE),
2385 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS),
2386 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS),
2387 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS),
2388 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM),
2389 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO),
2390 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM),
2391 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK),
2392 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH),
2393 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_X_MULTIFD),
2394
2395 DEFINE_PROP_END_OF_LIST(),
2396 };
2397
2398 static void migration_class_init(ObjectClass *klass, void *data)
2399 {
2400 DeviceClass *dc = DEVICE_CLASS(klass);
2401
2402 dc->user_creatable = false;
2403 dc->props = migration_properties;
2404 }
2405
2406 static void migration_instance_finalize(Object *obj)
2407 {
2408 MigrationState *ms = MIGRATION_OBJ(obj);
2409 MigrationParameters *params = &ms->parameters;
2410
2411 g_free(params->tls_hostname);
2412 g_free(params->tls_creds);
2413 qemu_sem_destroy(&ms->pause_sem);
2414 }
2415
2416 static void migration_instance_init(Object *obj)
2417 {
2418 MigrationState *ms = MIGRATION_OBJ(obj);
2419 MigrationParameters *params = &ms->parameters;
2420
2421 ms->state = MIGRATION_STATUS_NONE;
2422 ms->xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE;
2423 ms->mbps = -1;
2424 qemu_sem_init(&ms->pause_sem, 0);
2425
2426 params->tls_hostname = g_strdup("");
2427 params->tls_creds = g_strdup("");
2428
2429 /* Set has_* up only for parameter checks */
2430 params->has_compress_level = true;
2431 params->has_compress_threads = true;
2432 params->has_decompress_threads = true;
2433 params->has_cpu_throttle_initial = true;
2434 params->has_cpu_throttle_increment = true;
2435 params->has_max_bandwidth = true;
2436 params->has_downtime_limit = true;
2437 params->has_x_checkpoint_delay = true;
2438 params->has_block_incremental = true;
2439 params->has_x_multifd_channels = true;
2440 params->has_x_multifd_page_count = true;
2441 }
2442
2443 /*
2444 * Return true if check pass, false otherwise. Error will be put
2445 * inside errp if provided.
2446 */
2447 static bool migration_object_check(MigrationState *ms, Error **errp)
2448 {
2449 MigrationCapabilityStatusList *head = NULL;
2450 /* Assuming all off */
2451 bool cap_list[MIGRATION_CAPABILITY__MAX] = { 0 }, ret;
2452 int i;
2453
2454 if (!migrate_params_check(&ms->parameters, errp)) {
2455 return false;
2456 }
2457
2458 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
2459 if (ms->enabled_capabilities[i]) {
2460 head = migrate_cap_add(head, i, true);
2461 }
2462 }
2463
2464 ret = migrate_caps_check(cap_list, head, errp);
2465
2466 /* It works with head == NULL */
2467 qapi_free_MigrationCapabilityStatusList(head);
2468
2469 return ret;
2470 }
2471
2472 static const TypeInfo migration_type = {
2473 .name = TYPE_MIGRATION,
2474 /*
2475 * NOTE: TYPE_MIGRATION is not really a device, as the object is
2476 * not created using qdev_create(), it is not attached to the qdev
2477 * device tree, and it is never realized.
2478 *
2479 * TODO: Make this TYPE_OBJECT once QOM provides something like
2480 * TYPE_DEVICE's "-global" properties.
2481 */
2482 .parent = TYPE_DEVICE,
2483 .class_init = migration_class_init,
2484 .class_size = sizeof(MigrationClass),
2485 .instance_size = sizeof(MigrationState),
2486 .instance_init = migration_instance_init,
2487 .instance_finalize = migration_instance_finalize,
2488 };
2489
2490 static void register_migration_types(void)
2491 {
2492 type_register_static(&migration_type);
2493 }
2494
2495 type_init(register_migration_types);
QEmu