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migration: Wait for semaphore before completing migration
[qemu/ar7.git] / migration / migration.c
blobef84d2c1fb029c1a81cf7dfba5665324ab13a84d
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_set_cache_size(int64_t value, Error **errp)
1378 {
1379 MigrationState *s = migrate_get_current();
1380 int64_t new_size;
1381
1382 new_size = xbzrle_cache_resize(value, errp);
1383 if (new_size < 0) {
1384 return;
1385 }
1386
1387 s->xbzrle_cache_size = new_size;
1388 }
1389
1390 int64_t qmp_query_migrate_cache_size(Error **errp)
1391 {
1392 return migrate_xbzrle_cache_size();
1393 }
1394
1395 void qmp_migrate_set_speed(int64_t value, Error **errp)
1396 {
1397 MigrateSetParameters p = {
1398 .has_max_bandwidth = true,
1399 .max_bandwidth = value,
1400 };
1401
1402 qmp_migrate_set_parameters(&p, errp);
1403 }
1404
1405 void qmp_migrate_set_downtime(double value, Error **errp)
1406 {
1407 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) {
1408 error_setg(errp, "Parameter 'downtime_limit' expects an integer in "
1409 "the range of 0 to %d seconds",
1410 MAX_MIGRATE_DOWNTIME_SECONDS);
1411 return;
1412 }
1413
1414 value *= 1000; /* Convert to milliseconds */
1415 value = MAX(0, MIN(INT64_MAX, value));
1416
1417 MigrateSetParameters p = {
1418 .has_downtime_limit = true,
1419 .downtime_limit = value,
1420 };
1421
1422 qmp_migrate_set_parameters(&p, errp);
1423 }
1424
1425 bool migrate_release_ram(void)
1426 {
1427 MigrationState *s;
1428
1429 s = migrate_get_current();
1430
1431 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM];
1432 }
1433
1434 bool migrate_postcopy_ram(void)
1435 {
1436 MigrationState *s;
1437
1438 s = migrate_get_current();
1439
1440 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM];
1441 }
1442
1443 bool migrate_postcopy(void)
1444 {
1445 return migrate_postcopy_ram();
1446 }
1447
1448 bool migrate_auto_converge(void)
1449 {
1450 MigrationState *s;
1451
1452 s = migrate_get_current();
1453
1454 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
1455 }
1456
1457 bool migrate_zero_blocks(void)
1458 {
1459 MigrationState *s;
1460
1461 s = migrate_get_current();
1462
1463 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
1464 }
1465
1466 bool migrate_use_compression(void)
1467 {
1468 MigrationState *s;
1469
1470 s = migrate_get_current();
1471
1472 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
1473 }
1474
1475 int migrate_compress_level(void)
1476 {
1477 MigrationState *s;
1478
1479 s = migrate_get_current();
1480
1481 return s->parameters.compress_level;
1482 }
1483
1484 int migrate_compress_threads(void)
1485 {
1486 MigrationState *s;
1487
1488 s = migrate_get_current();
1489
1490 return s->parameters.compress_threads;
1491 }
1492
1493 int migrate_decompress_threads(void)
1494 {
1495 MigrationState *s;
1496
1497 s = migrate_get_current();
1498
1499 return s->parameters.decompress_threads;
1500 }
1501
1502 bool migrate_use_events(void)
1503 {
1504 MigrationState *s;
1505
1506 s = migrate_get_current();
1507
1508 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
1509 }
1510
1511 bool migrate_use_multifd(void)
1512 {
1513 MigrationState *s;
1514
1515 s = migrate_get_current();
1516
1517 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD];
1518 }
1519
1520 bool migrate_pause_before_switchover(void)
1521 {
1522 MigrationState *s;
1523
1524 s = migrate_get_current();
1525
1526 return s->enabled_capabilities[
1527 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
1528 }
1529
1530 int migrate_multifd_channels(void)
1531 {
1532 MigrationState *s;
1533
1534 s = migrate_get_current();
1535
1536 return s->parameters.x_multifd_channels;
1537 }
1538
1539 int migrate_multifd_page_count(void)
1540 {
1541 MigrationState *s;
1542
1543 s = migrate_get_current();
1544
1545 return s->parameters.x_multifd_page_count;
1546 }
1547
1548 int migrate_use_xbzrle(void)
1549 {
1550 MigrationState *s;
1551
1552 s = migrate_get_current();
1553
1554 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
1555 }
1556
1557 int64_t migrate_xbzrle_cache_size(void)
1558 {
1559 MigrationState *s;
1560
1561 s = migrate_get_current();
1562
1563 return s->xbzrle_cache_size;
1564 }
1565
1566 bool migrate_use_block(void)
1567 {
1568 MigrationState *s;
1569
1570 s = migrate_get_current();
1571
1572 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK];
1573 }
1574
1575 bool migrate_use_return_path(void)
1576 {
1577 MigrationState *s;
1578
1579 s = migrate_get_current();
1580
1581 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH];
1582 }
1583
1584 bool migrate_use_block_incremental(void)
1585 {
1586 MigrationState *s;
1587
1588 s = migrate_get_current();
1589
1590 return s->parameters.block_incremental;
1591 }
1592
1593 /* migration thread support */
1594 /*
1595 * Something bad happened to the RP stream, mark an error
1596 * The caller shall print or trace something to indicate why
1597 */
1598 static void mark_source_rp_bad(MigrationState *s)
1599 {
1600 s->rp_state.error = true;
1601 }
1602
1603 static struct rp_cmd_args {
1604 ssize_t len; /* -1 = variable */
1605 const char *name;
1606 } rp_cmd_args[] = {
1607 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
1608 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
1609 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
1610 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
1611 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
1612 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
1613 };
1614
1615 /*
1616 * Process a request for pages received on the return path,
1617 * We're allowed to send more than requested (e.g. to round to our page size)
1618 * and we don't need to send pages that have already been sent.
1619 */
1620 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
1621 ram_addr_t start, size_t len)
1622 {
1623 long our_host_ps = getpagesize();
1624
1625 trace_migrate_handle_rp_req_pages(rbname, start, len);
1626
1627 /*
1628 * Since we currently insist on matching page sizes, just sanity check
1629 * we're being asked for whole host pages.
1630 */
1631 if (start & (our_host_ps-1) ||
1632 (len & (our_host_ps-1))) {
1633 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
1634 " len: %zd", __func__, start, len);
1635 mark_source_rp_bad(ms);
1636 return;
1637 }
1638
1639 if (ram_save_queue_pages(rbname, start, len)) {
1640 mark_source_rp_bad(ms);
1641 }
1642 }
1643
1644 /*
1645 * Handles messages sent on the return path towards the source VM
1646 *
1647 */
1648 static void *source_return_path_thread(void *opaque)
1649 {
1650 MigrationState *ms = opaque;
1651 QEMUFile *rp = ms->rp_state.from_dst_file;
1652 uint16_t header_len, header_type;
1653 uint8_t buf[512];
1654 uint32_t tmp32, sibling_error;
1655 ram_addr_t start = 0; /* =0 to silence warning */
1656 size_t len = 0, expected_len;
1657 int res;
1658
1659 trace_source_return_path_thread_entry();
1660 while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
1661 migration_is_setup_or_active(ms->state)) {
1662 trace_source_return_path_thread_loop_top();
1663 header_type = qemu_get_be16(rp);
1664 header_len = qemu_get_be16(rp);
1665
1666 if (header_type >= MIG_RP_MSG_MAX ||
1667 header_type == MIG_RP_MSG_INVALID) {
1668 error_report("RP: Received invalid message 0x%04x length 0x%04x",
1669 header_type, header_len);
1670 mark_source_rp_bad(ms);
1671 goto out;
1672 }
1673
1674 if ((rp_cmd_args[header_type].len != -1 &&
1675 header_len != rp_cmd_args[header_type].len) ||
1676 header_len > sizeof(buf)) {
1677 error_report("RP: Received '%s' message (0x%04x) with"
1678 "incorrect length %d expecting %zu",
1679 rp_cmd_args[header_type].name, header_type, header_len,
1680 (size_t)rp_cmd_args[header_type].len);
1681 mark_source_rp_bad(ms);
1682 goto out;
1683 }
1684
1685 /* We know we've got a valid header by this point */
1686 res = qemu_get_buffer(rp, buf, header_len);
1687 if (res != header_len) {
1688 error_report("RP: Failed reading data for message 0x%04x"
1689 " read %d expected %d",
1690 header_type, res, header_len);
1691 mark_source_rp_bad(ms);
1692 goto out;
1693 }
1694
1695 /* OK, we have the message and the data */
1696 switch (header_type) {
1697 case MIG_RP_MSG_SHUT:
1698 sibling_error = ldl_be_p(buf);
1699 trace_source_return_path_thread_shut(sibling_error);
1700 if (sibling_error) {
1701 error_report("RP: Sibling indicated error %d", sibling_error);
1702 mark_source_rp_bad(ms);
1703 }
1704 /*
1705 * We'll let the main thread deal with closing the RP
1706 * we could do a shutdown(2) on it, but we're the only user
1707 * anyway, so there's nothing gained.
1708 */
1709 goto out;
1710
1711 case MIG_RP_MSG_PONG:
1712 tmp32 = ldl_be_p(buf);
1713 trace_source_return_path_thread_pong(tmp32);
1714 break;
1715
1716 case MIG_RP_MSG_REQ_PAGES:
1717 start = ldq_be_p(buf);
1718 len = ldl_be_p(buf + 8);
1719 migrate_handle_rp_req_pages(ms, NULL, start, len);
1720 break;
1721
1722 case MIG_RP_MSG_REQ_PAGES_ID:
1723 expected_len = 12 + 1; /* header + termination */
1724
1725 if (header_len >= expected_len) {
1726 start = ldq_be_p(buf);
1727 len = ldl_be_p(buf + 8);
1728 /* Now we expect an idstr */
1729 tmp32 = buf[12]; /* Length of the following idstr */
1730 buf[13 + tmp32] = '\0';
1731 expected_len += tmp32;
1732 }
1733 if (header_len != expected_len) {
1734 error_report("RP: Req_Page_id with length %d expecting %zd",
1735 header_len, expected_len);
1736 mark_source_rp_bad(ms);
1737 goto out;
1738 }
1739 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
1740 break;
1741
1742 default:
1743 break;
1744 }
1745 }
1746 if (qemu_file_get_error(rp)) {
1747 trace_source_return_path_thread_bad_end();
1748 mark_source_rp_bad(ms);
1749 }
1750
1751 trace_source_return_path_thread_end();
1752 out:
1753 ms->rp_state.from_dst_file = NULL;
1754 qemu_fclose(rp);
1755 return NULL;
1756 }
1757
1758 static int open_return_path_on_source(MigrationState *ms)
1759 {
1760
1761 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
1762 if (!ms->rp_state.from_dst_file) {
1763 return -1;
1764 }
1765
1766 trace_open_return_path_on_source();
1767 qemu_thread_create(&ms->rp_state.rp_thread, "return path",
1768 source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
1769
1770 trace_open_return_path_on_source_continue();
1771
1772 return 0;
1773 }
1774
1775 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1776 static int await_return_path_close_on_source(MigrationState *ms)
1777 {
1778 /*
1779 * If this is a normal exit then the destination will send a SHUT and the
1780 * rp_thread will exit, however if there's an error we need to cause
1781 * it to exit.
1782 */
1783 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) {
1784 /*
1785 * shutdown(2), if we have it, will cause it to unblock if it's stuck
1786 * waiting for the destination.
1787 */
1788 qemu_file_shutdown(ms->rp_state.from_dst_file);
1789 mark_source_rp_bad(ms);
1790 }
1791 trace_await_return_path_close_on_source_joining();
1792 qemu_thread_join(&ms->rp_state.rp_thread);
1793 trace_await_return_path_close_on_source_close();
1794 return ms->rp_state.error;
1795 }
1796
1797 /*
1798 * Switch from normal iteration to postcopy
1799 * Returns non-0 on error
1800 */
1801 static int postcopy_start(MigrationState *ms, bool *old_vm_running)
1802 {
1803 int ret;
1804 QIOChannelBuffer *bioc;
1805 QEMUFile *fb;
1806 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1807 bool restart_block = false;
1808 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
1809 MIGRATION_STATUS_POSTCOPY_ACTIVE);
1810
1811 trace_postcopy_start();
1812 qemu_mutex_lock_iothread();
1813 trace_postcopy_start_set_run();
1814
1815 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
1816 *old_vm_running = runstate_is_running();
1817 global_state_store();
1818 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
1819 if (ret < 0) {
1820 goto fail;
1821 }
1822
1823 ret = bdrv_inactivate_all();
1824 if (ret < 0) {
1825 goto fail;
1826 }
1827 restart_block = true;
1828
1829 /*
1830 * Cause any non-postcopiable, but iterative devices to
1831 * send out their final data.
1832 */
1833 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false);
1834
1835 /*
1836 * in Finish migrate and with the io-lock held everything should
1837 * be quiet, but we've potentially still got dirty pages and we
1838 * need to tell the destination to throw any pages it's already received
1839 * that are dirty
1840 */
1841 if (migrate_postcopy_ram()) {
1842 if (ram_postcopy_send_discard_bitmap(ms)) {
1843 error_report("postcopy send discard bitmap failed");
1844 goto fail;
1845 }
1846 }
1847
1848 /*
1849 * send rest of state - note things that are doing postcopy
1850 * will notice we're in POSTCOPY_ACTIVE and not actually
1851 * wrap their state up here
1852 */
1853 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);
1854 if (migrate_postcopy_ram()) {
1855 /* Ping just for debugging, helps line traces up */
1856 qemu_savevm_send_ping(ms->to_dst_file, 2);
1857 }
1858
1859 /*
1860 * While loading the device state we may trigger page transfer
1861 * requests and the fd must be free to process those, and thus
1862 * the destination must read the whole device state off the fd before
1863 * it starts processing it. Unfortunately the ad-hoc migration format
1864 * doesn't allow the destination to know the size to read without fully
1865 * parsing it through each devices load-state code (especially the open
1866 * coded devices that use get/put).
1867 * So we wrap the device state up in a package with a length at the start;
1868 * to do this we use a qemu_buf to hold the whole of the device state.
1869 */
1870 bioc = qio_channel_buffer_new(4096);
1871 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");
1872 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
1873 object_unref(OBJECT(bioc));
1874
1875 /*
1876 * Make sure the receiver can get incoming pages before we send the rest
1877 * of the state
1878 */
1879 qemu_savevm_send_postcopy_listen(fb);
1880
1881 qemu_savevm_state_complete_precopy(fb, false, false);
1882 if (migrate_postcopy_ram()) {
1883 qemu_savevm_send_ping(fb, 3);
1884 }
1885
1886 qemu_savevm_send_postcopy_run(fb);
1887
1888 /* <><> end of stuff going into the package */
1889
1890 /* Last point of recovery; as soon as we send the package the destination
1891 * can open devices and potentially start running.
1892 * Lets just check again we've not got any errors.
1893 */
1894 ret = qemu_file_get_error(ms->to_dst_file);
1895 if (ret) {
1896 error_report("postcopy_start: Migration stream errored (pre package)");
1897 goto fail_closefb;
1898 }
1899
1900 restart_block = false;
1901
1902 /* Now send that blob */
1903 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) {
1904 goto fail_closefb;
1905 }
1906 qemu_fclose(fb);
1907
1908 /* Send a notify to give a chance for anything that needs to happen
1909 * at the transition to postcopy and after the device state; in particular
1910 * spice needs to trigger a transition now
1911 */
1912 ms->postcopy_after_devices = true;
1913 notifier_list_notify(&migration_state_notifiers, ms);
1914
1915 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
1916
1917 qemu_mutex_unlock_iothread();
1918
1919 if (migrate_postcopy_ram()) {
1920 /*
1921 * Although this ping is just for debug, it could potentially be
1922 * used for getting a better measurement of downtime at the source.
1923 */
1924 qemu_savevm_send_ping(ms->to_dst_file, 4);
1925 }
1926
1927 if (migrate_release_ram()) {
1928 ram_postcopy_migrated_memory_release(ms);
1929 }
1930
1931 ret = qemu_file_get_error(ms->to_dst_file);
1932 if (ret) {
1933 error_report("postcopy_start: Migration stream errored");
1934 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1935 MIGRATION_STATUS_FAILED);
1936 }
1937
1938 return ret;
1939
1940 fail_closefb:
1941 qemu_fclose(fb);
1942 fail:
1943 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1944 MIGRATION_STATUS_FAILED);
1945 if (restart_block) {
1946 /* A failure happened early enough that we know the destination hasn't
1947 * accessed block devices, so we're safe to recover.
1948 */
1949 Error *local_err = NULL;
1950
1951 bdrv_invalidate_cache_all(&local_err);
1952 if (local_err) {
1953 error_report_err(local_err);
1954 }
1955 }
1956 qemu_mutex_unlock_iothread();
1957 return -1;
1958 }
1959
1960 /**
1961 * migration_maybe_pause: Pause if required to by
1962 * migrate_pause_before_switchover called with the iothread locked
1963 * Returns: 0 on success
1964 */
1965 static int migration_maybe_pause(MigrationState *s, int *current_active_state)
1966 {
1967 if (!migrate_pause_before_switchover()) {
1968 return 0;
1969 }
1970
1971 /* Since leaving this state is not atomic with posting the semaphore
1972 * it's possible that someone could have issued multiple migrate_continue
1973 * and the semaphore is incorrectly positive at this point;
1974 * the docs say it's undefined to reinit a semaphore that's already
1975 * init'd, so use timedwait to eat up any existing posts.
1976 */
1977 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
1978 /* This block intentionally left blank */
1979 }
1980
1981 qemu_mutex_unlock_iothread();
1982 migrate_set_state(&s->state, *current_active_state,
1983 MIGRATION_STATUS_PRE_SWITCHOVER);
1984 qemu_sem_wait(&s->pause_sem);
1985 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
1986 MIGRATION_STATUS_DEVICE);
1987 *current_active_state = MIGRATION_STATUS_DEVICE;
1988 qemu_mutex_lock_iothread();
1989
1990 return s->state == MIGRATION_STATUS_DEVICE ? 0 : -EINVAL;
1991 }
1992
1993 /**
1994 * migration_completion: Used by migration_thread when there's not much left.
1995 * The caller 'breaks' the loop when this returns.
1996 *
1997 * @s: Current migration state
1998 * @current_active_state: The migration state we expect to be in
1999 * @*old_vm_running: Pointer to old_vm_running flag
2000 * @*start_time: Pointer to time to update
2001 */
2002 static void migration_completion(MigrationState *s, int current_active_state,
2003 bool *old_vm_running,
2004 int64_t *start_time)
2005 {
2006 int ret;
2007
2008 if (s->state == MIGRATION_STATUS_ACTIVE) {
2009 qemu_mutex_lock_iothread();
2010 *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2011 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
2012 *old_vm_running = runstate_is_running();
2013 ret = global_state_store();
2014
2015 if (!ret) {
2016 bool inactivate = !migrate_colo_enabled();
2017 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2018 if (ret >= 0) {
2019 ret = migration_maybe_pause(s, &current_active_state);
2020 }
2021 if (ret >= 0) {
2022 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
2023 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
2024 inactivate);
2025 }
2026 if (inactivate && ret >= 0) {
2027 s->block_inactive = true;
2028 }
2029 }
2030 qemu_mutex_unlock_iothread();
2031
2032 if (ret < 0) {
2033 goto fail;
2034 }
2035 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2036 trace_migration_completion_postcopy_end();
2037
2038 qemu_savevm_state_complete_postcopy(s->to_dst_file);
2039 trace_migration_completion_postcopy_end_after_complete();
2040 }
2041
2042 /*
2043 * If rp was opened we must clean up the thread before
2044 * cleaning everything else up (since if there are no failures
2045 * it will wait for the destination to send it's status in
2046 * a SHUT command).
2047 */
2048 if (s->rp_state.from_dst_file) {
2049 int rp_error;
2050 trace_migration_return_path_end_before();
2051 rp_error = await_return_path_close_on_source(s);
2052 trace_migration_return_path_end_after(rp_error);
2053 if (rp_error) {
2054 goto fail_invalidate;
2055 }
2056 }
2057
2058 if (qemu_file_get_error(s->to_dst_file)) {
2059 trace_migration_completion_file_err();
2060 goto fail_invalidate;
2061 }
2062
2063 if (!migrate_colo_enabled()) {
2064 migrate_set_state(&s->state, current_active_state,
2065 MIGRATION_STATUS_COMPLETED);
2066 }
2067
2068 return;
2069
2070 fail_invalidate:
2071 /* If not doing postcopy, vm_start() will be called: let's regain
2072 * control on images.
2073 */
2074 if (s->state == MIGRATION_STATUS_ACTIVE) {
2075 Error *local_err = NULL;
2076
2077 qemu_mutex_lock_iothread();
2078 bdrv_invalidate_cache_all(&local_err);
2079 if (local_err) {
2080 error_report_err(local_err);
2081 } else {
2082 s->block_inactive = false;
2083 }
2084 qemu_mutex_unlock_iothread();
2085 }
2086
2087 fail:
2088 migrate_set_state(&s->state, current_active_state,
2089 MIGRATION_STATUS_FAILED);
2090 }
2091
2092 bool migrate_colo_enabled(void)
2093 {
2094 MigrationState *s = migrate_get_current();
2095 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
2096 }
2097
2098 /*
2099 * Master migration thread on the source VM.
2100 * It drives the migration and pumps the data down the outgoing channel.
2101 */
2102 static void *migration_thread(void *opaque)
2103 {
2104 MigrationState *s = opaque;
2105 /* Used by the bandwidth calcs, updated later */
2106 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2107 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
2108 int64_t initial_bytes = 0;
2109 /*
2110 * The final stage happens when the remaining data is smaller than
2111 * this threshold; it's calculated from the requested downtime and
2112 * measured bandwidth
2113 */
2114 int64_t threshold_size = 0;
2115 int64_t start_time = initial_time;
2116 int64_t end_time;
2117 bool old_vm_running = false;
2118 bool entered_postcopy = false;
2119 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
2120 enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
2121 bool enable_colo = migrate_colo_enabled();
2122
2123 rcu_register_thread();
2124
2125 qemu_savevm_state_header(s->to_dst_file);
2126
2127 /*
2128 * If we opened the return path, we need to make sure dst has it
2129 * opened as well.
2130 */
2131 if (s->rp_state.from_dst_file) {
2132 /* Now tell the dest that it should open its end so it can reply */
2133 qemu_savevm_send_open_return_path(s->to_dst_file);
2134
2135 /* And do a ping that will make stuff easier to debug */
2136 qemu_savevm_send_ping(s->to_dst_file, 1);
2137 }
2138
2139 if (migrate_postcopy()) {
2140 /*
2141 * Tell the destination that we *might* want to do postcopy later;
2142 * if the other end can't do postcopy it should fail now, nice and
2143 * early.
2144 */
2145 qemu_savevm_send_postcopy_advise(s->to_dst_file);
2146 }
2147
2148 qemu_savevm_state_setup(s->to_dst_file);
2149
2150 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
2151 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2152 MIGRATION_STATUS_ACTIVE);
2153
2154 trace_migration_thread_setup_complete();
2155
2156 while (s->state == MIGRATION_STATUS_ACTIVE ||
2157 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2158 int64_t current_time;
2159 uint64_t pending_size;
2160
2161 if (!qemu_file_rate_limit(s->to_dst_file)) {
2162 uint64_t pend_post, pend_nonpost;
2163
2164 qemu_savevm_state_pending(s->to_dst_file, threshold_size,
2165 &pend_nonpost, &pend_post);
2166 pending_size = pend_nonpost + pend_post;
2167 trace_migrate_pending(pending_size, threshold_size,
2168 pend_post, pend_nonpost);
2169 if (pending_size && pending_size >= threshold_size) {
2170 /* Still a significant amount to transfer */
2171
2172 if (migrate_postcopy() &&
2173 s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE &&
2174 pend_nonpost <= threshold_size &&
2175 atomic_read(&s->start_postcopy)) {
2176
2177 if (!postcopy_start(s, &old_vm_running)) {
2178 current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE;
2179 entered_postcopy = true;
2180 }
2181
2182 continue;
2183 }
2184 /* Just another iteration step */
2185 qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy);
2186 } else {
2187 trace_migration_thread_low_pending(pending_size);
2188 migration_completion(s, current_active_state,
2189 &old_vm_running, &start_time);
2190 break;
2191 }
2192 }
2193
2194 if (qemu_file_get_error(s->to_dst_file)) {
2195 migrate_set_state(&s->state, current_active_state,
2196 MIGRATION_STATUS_FAILED);
2197 trace_migration_thread_file_err();
2198 break;
2199 }
2200 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2201 if (current_time >= initial_time + BUFFER_DELAY) {
2202 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file) -
2203 initial_bytes;
2204 uint64_t time_spent = current_time - initial_time;
2205 double bandwidth = (double)transferred_bytes / time_spent;
2206 threshold_size = bandwidth * s->parameters.downtime_limit;
2207
2208 s->mbps = (((double) transferred_bytes * 8.0) /
2209 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
2210
2211 trace_migrate_transferred(transferred_bytes, time_spent,
2212 bandwidth, threshold_size);
2213 /* if we haven't sent anything, we don't want to recalculate
2214 10000 is a small enough number for our purposes */
2215 if (ram_counters.dirty_pages_rate && transferred_bytes > 10000) {
2216 s->expected_downtime = ram_counters.dirty_pages_rate *
2217 qemu_target_page_size() / bandwidth;
2218 }
2219
2220 qemu_file_reset_rate_limit(s->to_dst_file);
2221 initial_time = current_time;
2222 initial_bytes = qemu_ftell(s->to_dst_file);
2223 }
2224 if (qemu_file_rate_limit(s->to_dst_file)) {
2225 /* usleep expects microseconds */
2226 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
2227 }
2228 }
2229
2230 trace_migration_thread_after_loop();
2231 /* If we enabled cpu throttling for auto-converge, turn it off. */
2232 cpu_throttle_stop();
2233 end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2234
2235 qemu_mutex_lock_iothread();
2236 /*
2237 * The resource has been allocated by migration will be reused in COLO
2238 * process, so don't release them.
2239 */
2240 if (!enable_colo) {
2241 qemu_savevm_state_cleanup();
2242 }
2243 if (s->state == MIGRATION_STATUS_COMPLETED) {
2244 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file);
2245 s->total_time = end_time - s->total_time;
2246 if (!entered_postcopy) {
2247 s->downtime = end_time - start_time;
2248 }
2249 if (s->total_time) {
2250 s->mbps = (((double) transferred_bytes * 8.0) /
2251 ((double) s->total_time)) / 1000;
2252 }
2253 runstate_set(RUN_STATE_POSTMIGRATE);
2254 } else {
2255 if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) {
2256 migrate_start_colo_process(s);
2257 qemu_savevm_state_cleanup();
2258 /*
2259 * Fixme: we will run VM in COLO no matter its old running state.
2260 * After exited COLO, we will keep running.
2261 */
2262 old_vm_running = true;
2263 }
2264 if (old_vm_running && !entered_postcopy) {
2265 vm_start();
2266 } else {
2267 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
2268 runstate_set(RUN_STATE_POSTMIGRATE);
2269 }
2270 }
2271 }
2272 qemu_bh_schedule(s->cleanup_bh);
2273 qemu_mutex_unlock_iothread();
2274
2275 rcu_unregister_thread();
2276 return NULL;
2277 }
2278
2279 void migrate_fd_connect(MigrationState *s)
2280 {
2281 s->expected_downtime = s->parameters.downtime_limit;
2282 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
2283
2284 qemu_file_set_blocking(s->to_dst_file, true);
2285 qemu_file_set_rate_limit(s->to_dst_file,
2286 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
2287
2288 /* Notify before starting migration thread */
2289 notifier_list_notify(&migration_state_notifiers, s);
2290
2291 /*
2292 * Open the return path. For postcopy, it is used exclusively. For
2293 * precopy, only if user specified "return-path" capability would
2294 * QEMU uses the return path.
2295 */
2296 if (migrate_postcopy_ram() || migrate_use_return_path()) {
2297 if (open_return_path_on_source(s)) {
2298 error_report("Unable to open return-path for postcopy");
2299 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2300 MIGRATION_STATUS_FAILED);
2301 migrate_fd_cleanup(s);
2302 return;
2303 }
2304 }
2305
2306 if (multifd_save_setup() != 0) {
2307 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2308 MIGRATION_STATUS_FAILED);
2309 migrate_fd_cleanup(s);
2310 return;
2311 }
2312 qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
2313 QEMU_THREAD_JOINABLE);
2314 s->migration_thread_running = true;
2315 }
2316
2317 void migration_global_dump(Monitor *mon)
2318 {
2319 MigrationState *ms = migrate_get_current();
2320
2321 monitor_printf(mon, "globals: store-global-state=%d, only_migratable=%d, "
2322 "send-configuration=%d, send-section-footer=%d\n",
2323 ms->store_global_state, ms->only_migratable,
2324 ms->send_configuration, ms->send_section_footer);
2325 }
2326
2327 #define DEFINE_PROP_MIG_CAP(name, x) \
2328 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false)
2329
2330 static Property migration_properties[] = {
2331 DEFINE_PROP_BOOL("store-global-state", MigrationState,
2332 store_global_state, true),
2333 DEFINE_PROP_BOOL("only-migratable", MigrationState, only_migratable, false),
2334 DEFINE_PROP_BOOL("send-configuration", MigrationState,
2335 send_configuration, true),
2336 DEFINE_PROP_BOOL("send-section-footer", MigrationState,
2337 send_section_footer, true),
2338
2339 /* Migration parameters */
2340 DEFINE_PROP_INT64("x-compress-level", MigrationState,
2341 parameters.compress_level,
2342 DEFAULT_MIGRATE_COMPRESS_LEVEL),
2343 DEFINE_PROP_INT64("x-compress-threads", MigrationState,
2344 parameters.compress_threads,
2345 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT),
2346 DEFINE_PROP_INT64("x-decompress-threads", MigrationState,
2347 parameters.decompress_threads,
2348 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT),
2349 DEFINE_PROP_INT64("x-cpu-throttle-initial", MigrationState,
2350 parameters.cpu_throttle_initial,
2351 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL),
2352 DEFINE_PROP_INT64("x-cpu-throttle-increment", MigrationState,
2353 parameters.cpu_throttle_increment,
2354 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT),
2355 DEFINE_PROP_INT64("x-max-bandwidth", MigrationState,
2356 parameters.max_bandwidth, MAX_THROTTLE),
2357 DEFINE_PROP_INT64("x-downtime-limit", MigrationState,
2358 parameters.downtime_limit,
2359 DEFAULT_MIGRATE_SET_DOWNTIME),
2360 DEFINE_PROP_INT64("x-checkpoint-delay", MigrationState,
2361 parameters.x_checkpoint_delay,
2362 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY),
2363 DEFINE_PROP_INT64("x-multifd-channels", MigrationState,
2364 parameters.x_multifd_channels,
2365 DEFAULT_MIGRATE_MULTIFD_CHANNELS),
2366 DEFINE_PROP_INT64("x-multifd-page-count", MigrationState,
2367 parameters.x_multifd_page_count,
2368 DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT),
2369
2370 /* Migration capabilities */
2371 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
2372 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL),
2373 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE),
2374 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS),
2375 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS),
2376 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS),
2377 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM),
2378 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO),
2379 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM),
2380 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK),
2381 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH),
2382 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_X_MULTIFD),
2383
2384 DEFINE_PROP_END_OF_LIST(),
2385 };
2386
2387 static void migration_class_init(ObjectClass *klass, void *data)
2388 {
2389 DeviceClass *dc = DEVICE_CLASS(klass);
2390
2391 dc->user_creatable = false;
2392 dc->props = migration_properties;
2393 }
2394
2395 static void migration_instance_finalize(Object *obj)
2396 {
2397 MigrationState *ms = MIGRATION_OBJ(obj);
2398 MigrationParameters *params = &ms->parameters;
2399
2400 g_free(params->tls_hostname);
2401 g_free(params->tls_creds);
2402 qemu_sem_destroy(&ms->pause_sem);
2403 }
2404
2405 static void migration_instance_init(Object *obj)
2406 {
2407 MigrationState *ms = MIGRATION_OBJ(obj);
2408 MigrationParameters *params = &ms->parameters;
2409
2410 ms->state = MIGRATION_STATUS_NONE;
2411 ms->xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE;
2412 ms->mbps = -1;
2413 qemu_sem_init(&ms->pause_sem, 0);
2414
2415 params->tls_hostname = g_strdup("");
2416 params->tls_creds = g_strdup("");
2417
2418 /* Set has_* up only for parameter checks */
2419 params->has_compress_level = true;
2420 params->has_compress_threads = true;
2421 params->has_decompress_threads = true;
2422 params->has_cpu_throttle_initial = true;
2423 params->has_cpu_throttle_increment = true;
2424 params->has_max_bandwidth = true;
2425 params->has_downtime_limit = true;
2426 params->has_x_checkpoint_delay = true;
2427 params->has_block_incremental = true;
2428 params->has_x_multifd_channels = true;
2429 params->has_x_multifd_page_count = true;
2430 }
2431
2432 /*
2433 * Return true if check pass, false otherwise. Error will be put
2434 * inside errp if provided.
2435 */
2436 static bool migration_object_check(MigrationState *ms, Error **errp)
2437 {
2438 MigrationCapabilityStatusList *head = NULL;
2439 /* Assuming all off */
2440 bool cap_list[MIGRATION_CAPABILITY__MAX] = { 0 }, ret;
2441 int i;
2442
2443 if (!migrate_params_check(&ms->parameters, errp)) {
2444 return false;
2445 }
2446
2447 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
2448 if (ms->enabled_capabilities[i]) {
2449 head = migrate_cap_add(head, i, true);
2450 }
2451 }
2452
2453 ret = migrate_caps_check(cap_list, head, errp);
2454
2455 /* It works with head == NULL */
2456 qapi_free_MigrationCapabilityStatusList(head);
2457
2458 return ret;
2459 }
2460
2461 static const TypeInfo migration_type = {
2462 .name = TYPE_MIGRATION,
2463 /*
2464 * NOTE: TYPE_MIGRATION is not really a device, as the object is
2465 * not created using qdev_create(), it is not attached to the qdev
2466 * device tree, and it is never realized.
2467 *
2468 * TODO: Make this TYPE_OBJECT once QOM provides something like
2469 * TYPE_DEVICE's "-global" properties.
2470 */
2471 .parent = TYPE_DEVICE,
2472 .class_init = migration_class_init,
2473 .class_size = sizeof(MigrationClass),
2474 .instance_size = sizeof(MigrationState),
2475 .instance_init = migration_instance_init,
2476 .instance_finalize = migration_instance_finalize,
2477 };
2478
2479 static void register_migration_types(void)
2480 {
2481 type_register_static(&migration_type);
2482 }
2483
2484 type_init(register_migration_types);
AR7 emulation for QEMU