vmxnet3: Use common MAC address tracing macros
[qemu.git] / migration / migration.c
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 "qemu/main-loop.h"
20 #include "migration/migration.h"
21 #include "migration/qemu-file.h"
22 #include "sysemu/sysemu.h"
23 #include "block/block.h"
24 #include "qapi/qmp/qerror.h"
25 #include "qapi/util.h"
26 #include "qemu/sockets.h"
27 #include "qemu/rcu.h"
28 #include "migration/block.h"
29 #include "migration/postcopy-ram.h"
30 #include "qemu/thread.h"
31 #include "qmp-commands.h"
32 #include "trace.h"
33 #include "qapi-event.h"
34 #include "qom/cpu.h"
35 #include "exec/memory.h"
36 #include "exec/address-spaces.h"
37
38 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
39
40 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
41 * data. */
42 #define BUFFER_DELAY 100
43 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
44
45 /* Default compression thread count */
46 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
47 /* Default decompression thread count, usually decompression is at
48 * least 4 times as fast as compression.*/
49 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
50 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
51 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
52 /* Define default autoconverge cpu throttle migration parameters */
53 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
54 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
55
56 /* Migration XBZRLE default cache size */
57 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
58
59 static NotifierList migration_state_notifiers =
60 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
61
62 static bool deferred_incoming;
63
64 /*
65 * Current state of incoming postcopy; note this is not part of
66 * MigrationIncomingState since it's state is used during cleanup
67 * at the end as MIS is being freed.
68 */
69 static PostcopyState incoming_postcopy_state;
70
71 /* When we add fault tolerance, we could have several
72 migrations at once. For now we don't need to add
73 dynamic creation of migration */
74
75 /* For outgoing */
76 MigrationState *migrate_get_current(void)
77 {
78 static bool once;
79 static MigrationState current_migration = {
80 .state = MIGRATION_STATUS_NONE,
81 .bandwidth_limit = MAX_THROTTLE,
82 .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
83 .mbps = -1,
84 .parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] =
85 DEFAULT_MIGRATE_COMPRESS_LEVEL,
86 .parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
87 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT,
88 .parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
89 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
90 .parameters[MIGRATION_PARAMETER_CPU_THROTTLE_INITIAL] =
91 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL,
92 .parameters[MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT] =
93 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT,
94 };
95
96 if (!once) {
97 qemu_mutex_init(&current_migration.src_page_req_mutex);
98 once = true;
99 }
100 return &current_migration;
101 }
102
103 /* For incoming */
104 static MigrationIncomingState *mis_current;
105
106 MigrationIncomingState *migration_incoming_get_current(void)
107 {
108 return mis_current;
109 }
110
111 MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
112 {
113 mis_current = g_new0(MigrationIncomingState, 1);
114 mis_current->from_src_file = f;
115 mis_current->state = MIGRATION_STATUS_NONE;
116 QLIST_INIT(&mis_current->loadvm_handlers);
117 qemu_mutex_init(&mis_current->rp_mutex);
118 qemu_event_init(&mis_current->main_thread_load_event, false);
119
120 return mis_current;
121 }
122
123 void migration_incoming_state_destroy(void)
124 {
125 qemu_event_destroy(&mis_current->main_thread_load_event);
126 loadvm_free_handlers(mis_current);
127 g_free(mis_current);
128 mis_current = NULL;
129 }
130
131
132 typedef struct {
133 bool optional;
134 uint32_t size;
135 uint8_t runstate[100];
136 RunState state;
137 bool received;
138 } GlobalState;
139
140 static GlobalState global_state;
141
142 int global_state_store(void)
143 {
144 if (!runstate_store((char *)global_state.runstate,
145 sizeof(global_state.runstate))) {
146 error_report("runstate name too big: %s", global_state.runstate);
147 trace_migrate_state_too_big();
148 return -EINVAL;
149 }
150 return 0;
151 }
152
153 void global_state_store_running(void)
154 {
155 const char *state = RunState_lookup[RUN_STATE_RUNNING];
156 strncpy((char *)global_state.runstate,
157 state, sizeof(global_state.runstate));
158 }
159
160 static bool global_state_received(void)
161 {
162 return global_state.received;
163 }
164
165 static RunState global_state_get_runstate(void)
166 {
167 return global_state.state;
168 }
169
170 void global_state_set_optional(void)
171 {
172 global_state.optional = true;
173 }
174
175 static bool global_state_needed(void *opaque)
176 {
177 GlobalState *s = opaque;
178 char *runstate = (char *)s->runstate;
179
180 /* If it is not optional, it is mandatory */
181
182 if (s->optional == false) {
183 return true;
184 }
185
186 /* If state is running or paused, it is not needed */
187
188 if (strcmp(runstate, "running") == 0 ||
189 strcmp(runstate, "paused") == 0) {
190 return false;
191 }
192
193 /* for any other state it is needed */
194 return true;
195 }
196
197 static int global_state_post_load(void *opaque, int version_id)
198 {
199 GlobalState *s = opaque;
200 Error *local_err = NULL;
201 int r;
202 char *runstate = (char *)s->runstate;
203
204 s->received = true;
205 trace_migrate_global_state_post_load(runstate);
206
207 r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE__MAX,
208 -1, &local_err);
209
210 if (r == -1) {
211 if (local_err) {
212 error_report_err(local_err);
213 }
214 return -EINVAL;
215 }
216 s->state = r;
217
218 return 0;
219 }
220
221 static void global_state_pre_save(void *opaque)
222 {
223 GlobalState *s = opaque;
224
225 trace_migrate_global_state_pre_save((char *)s->runstate);
226 s->size = strlen((char *)s->runstate) + 1;
227 }
228
229 static const VMStateDescription vmstate_globalstate = {
230 .name = "globalstate",
231 .version_id = 1,
232 .minimum_version_id = 1,
233 .post_load = global_state_post_load,
234 .pre_save = global_state_pre_save,
235 .needed = global_state_needed,
236 .fields = (VMStateField[]) {
237 VMSTATE_UINT32(size, GlobalState),
238 VMSTATE_BUFFER(runstate, GlobalState),
239 VMSTATE_END_OF_LIST()
240 },
241 };
242
243 void register_global_state(void)
244 {
245 /* We would use it independently that we receive it */
246 strcpy((char *)&global_state.runstate, "");
247 global_state.received = false;
248 vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
249 }
250
251 static void migrate_generate_event(int new_state)
252 {
253 if (migrate_use_events()) {
254 qapi_event_send_migration(new_state, &error_abort);
255 }
256 }
257
258 /*
259 * Called on -incoming with a defer: uri.
260 * The migration can be started later after any parameters have been
261 * changed.
262 */
263 static void deferred_incoming_migration(Error **errp)
264 {
265 if (deferred_incoming) {
266 error_setg(errp, "Incoming migration already deferred");
267 }
268 deferred_incoming = true;
269 }
270
271 /* Request a range of pages from the source VM at the given
272 * start address.
273 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
274 * as the last request (a name must have been given previously)
275 * Start: Address offset within the RB
276 * Len: Length in bytes required - must be a multiple of pagesize
277 */
278 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
279 ram_addr_t start, size_t len)
280 {
281 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
282 size_t msglen = 12; /* start + len */
283
284 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
285 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
286
287 if (rbname) {
288 int rbname_len = strlen(rbname);
289 assert(rbname_len < 256);
290
291 bufc[msglen++] = rbname_len;
292 memcpy(bufc + msglen, rbname, rbname_len);
293 msglen += rbname_len;
294 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc);
295 } else {
296 migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc);
297 }
298 }
299
300 void qemu_start_incoming_migration(const char *uri, Error **errp)
301 {
302 const char *p;
303
304 qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort);
305 if (!strcmp(uri, "defer")) {
306 deferred_incoming_migration(errp);
307 } else if (strstart(uri, "tcp:", &p)) {
308 tcp_start_incoming_migration(p, errp);
309 #ifdef CONFIG_RDMA
310 } else if (strstart(uri, "rdma:", &p)) {
311 rdma_start_incoming_migration(p, errp);
312 #endif
313 #if !defined(WIN32)
314 } else if (strstart(uri, "exec:", &p)) {
315 exec_start_incoming_migration(p, errp);
316 } else if (strstart(uri, "unix:", &p)) {
317 unix_start_incoming_migration(p, errp);
318 } else if (strstart(uri, "fd:", &p)) {
319 fd_start_incoming_migration(p, errp);
320 #endif
321 } else {
322 error_setg(errp, "unknown migration protocol: %s", uri);
323 }
324 }
325
326 static void process_incoming_migration_bh(void *opaque)
327 {
328 Error *local_err = NULL;
329 MigrationIncomingState *mis = opaque;
330
331 /* Make sure all file formats flush their mutable metadata */
332 bdrv_invalidate_cache_all(&local_err);
333 if (local_err) {
334 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
335 MIGRATION_STATUS_FAILED);
336 error_report_err(local_err);
337 migrate_decompress_threads_join();
338 exit(EXIT_FAILURE);
339 }
340
341 /*
342 * This must happen after all error conditions are dealt with and
343 * we're sure the VM is going to be running on this host.
344 */
345 qemu_announce_self();
346
347 /* If global state section was not received or we are in running
348 state, we need to obey autostart. Any other state is set with
349 runstate_set. */
350
351 if (!global_state_received() ||
352 global_state_get_runstate() == RUN_STATE_RUNNING) {
353 if (autostart) {
354 vm_start();
355 } else {
356 runstate_set(RUN_STATE_PAUSED);
357 }
358 } else {
359 runstate_set(global_state_get_runstate());
360 }
361 migrate_decompress_threads_join();
362 /*
363 * This must happen after any state changes since as soon as an external
364 * observer sees this event they might start to prod at the VM assuming
365 * it's ready to use.
366 */
367 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
368 MIGRATION_STATUS_COMPLETED);
369 qemu_bh_delete(mis->bh);
370 migration_incoming_state_destroy();
371 }
372
373 static void process_incoming_migration_co(void *opaque)
374 {
375 QEMUFile *f = opaque;
376 MigrationIncomingState *mis;
377 PostcopyState ps;
378 int ret;
379
380 mis = migration_incoming_state_new(f);
381 postcopy_state_set(POSTCOPY_INCOMING_NONE);
382 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
383 MIGRATION_STATUS_ACTIVE);
384 ret = qemu_loadvm_state(f);
385
386 ps = postcopy_state_get();
387 trace_process_incoming_migration_co_end(ret, ps);
388 if (ps != POSTCOPY_INCOMING_NONE) {
389 if (ps == POSTCOPY_INCOMING_ADVISE) {
390 /*
391 * Where a migration had postcopy enabled (and thus went to advise)
392 * but managed to complete within the precopy period, we can use
393 * the normal exit.
394 */
395 postcopy_ram_incoming_cleanup(mis);
396 } else if (ret >= 0) {
397 /*
398 * Postcopy was started, cleanup should happen at the end of the
399 * postcopy thread.
400 */
401 trace_process_incoming_migration_co_postcopy_end_main();
402 return;
403 }
404 /* Else if something went wrong then just fall out of the normal exit */
405 }
406
407 qemu_fclose(f);
408 free_xbzrle_decoded_buf();
409
410 if (ret < 0) {
411 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
412 MIGRATION_STATUS_FAILED);
413 error_report("load of migration failed: %s", strerror(-ret));
414 migrate_decompress_threads_join();
415 exit(EXIT_FAILURE);
416 }
417
418 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
419 qemu_bh_schedule(mis->bh);
420 }
421
422 void process_incoming_migration(QEMUFile *f)
423 {
424 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
425 int fd = qemu_get_fd(f);
426
427 assert(fd != -1);
428 migrate_decompress_threads_create();
429 qemu_set_nonblock(fd);
430 qemu_coroutine_enter(co, f);
431 }
432
433 /*
434 * Send a message on the return channel back to the source
435 * of the migration.
436 */
437 void migrate_send_rp_message(MigrationIncomingState *mis,
438 enum mig_rp_message_type message_type,
439 uint16_t len, void *data)
440 {
441 trace_migrate_send_rp_message((int)message_type, len);
442 qemu_mutex_lock(&mis->rp_mutex);
443 qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
444 qemu_put_be16(mis->to_src_file, len);
445 qemu_put_buffer(mis->to_src_file, data, len);
446 qemu_fflush(mis->to_src_file);
447 qemu_mutex_unlock(&mis->rp_mutex);
448 }
449
450 /*
451 * Send a 'SHUT' message on the return channel with the given value
452 * to indicate that we've finished with the RP. Non-0 value indicates
453 * error.
454 */
455 void migrate_send_rp_shut(MigrationIncomingState *mis,
456 uint32_t value)
457 {
458 uint32_t buf;
459
460 buf = cpu_to_be32(value);
461 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
462 }
463
464 /*
465 * Send a 'PONG' message on the return channel with the given value
466 * (normally in response to a 'PING')
467 */
468 void migrate_send_rp_pong(MigrationIncomingState *mis,
469 uint32_t value)
470 {
471 uint32_t buf;
472
473 buf = cpu_to_be32(value);
474 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
475 }
476
477 /* amount of nanoseconds we are willing to wait for migration to be down.
478 * the choice of nanoseconds is because it is the maximum resolution that
479 * get_clock() can achieve. It is an internal measure. All user-visible
480 * units must be in seconds */
481 static uint64_t max_downtime = 300000000;
482
483 uint64_t migrate_max_downtime(void)
484 {
485 return max_downtime;
486 }
487
488 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
489 {
490 MigrationCapabilityStatusList *head = NULL;
491 MigrationCapabilityStatusList *caps;
492 MigrationState *s = migrate_get_current();
493 int i;
494
495 caps = NULL; /* silence compiler warning */
496 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
497 if (head == NULL) {
498 head = g_malloc0(sizeof(*caps));
499 caps = head;
500 } else {
501 caps->next = g_malloc0(sizeof(*caps));
502 caps = caps->next;
503 }
504 caps->value =
505 g_malloc(sizeof(*caps->value));
506 caps->value->capability = i;
507 caps->value->state = s->enabled_capabilities[i];
508 }
509
510 return head;
511 }
512
513 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
514 {
515 MigrationParameters *params;
516 MigrationState *s = migrate_get_current();
517
518 params = g_malloc0(sizeof(*params));
519 params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
520 params->compress_threads =
521 s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
522 params->decompress_threads =
523 s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
524 params->cpu_throttle_initial =
525 s->parameters[MIGRATION_PARAMETER_CPU_THROTTLE_INITIAL];
526 params->cpu_throttle_increment =
527 s->parameters[MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT];
528
529 return params;
530 }
531
532 /*
533 * Return true if we're already in the middle of a migration
534 * (i.e. any of the active or setup states)
535 */
536 static bool migration_is_setup_or_active(int state)
537 {
538 switch (state) {
539 case MIGRATION_STATUS_ACTIVE:
540 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
541 case MIGRATION_STATUS_SETUP:
542 return true;
543
544 default:
545 return false;
546
547 }
548 }
549
550 static void get_xbzrle_cache_stats(MigrationInfo *info)
551 {
552 if (migrate_use_xbzrle()) {
553 info->has_xbzrle_cache = true;
554 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
555 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
556 info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
557 info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
558 info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
559 info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate();
560 info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
561 }
562 }
563
564 MigrationInfo *qmp_query_migrate(Error **errp)
565 {
566 MigrationInfo *info = g_malloc0(sizeof(*info));
567 MigrationState *s = migrate_get_current();
568
569 switch (s->state) {
570 case MIGRATION_STATUS_NONE:
571 /* no migration has happened ever */
572 break;
573 case MIGRATION_STATUS_SETUP:
574 info->has_status = true;
575 info->has_total_time = false;
576 break;
577 case MIGRATION_STATUS_ACTIVE:
578 case MIGRATION_STATUS_CANCELLING:
579 info->has_status = true;
580 info->has_total_time = true;
581 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
582 - s->total_time;
583 info->has_expected_downtime = true;
584 info->expected_downtime = s->expected_downtime;
585 info->has_setup_time = true;
586 info->setup_time = s->setup_time;
587
588 info->has_ram = true;
589 info->ram = g_malloc0(sizeof(*info->ram));
590 info->ram->transferred = ram_bytes_transferred();
591 info->ram->remaining = ram_bytes_remaining();
592 info->ram->total = ram_bytes_total();
593 info->ram->duplicate = dup_mig_pages_transferred();
594 info->ram->skipped = skipped_mig_pages_transferred();
595 info->ram->normal = norm_mig_pages_transferred();
596 info->ram->normal_bytes = norm_mig_bytes_transferred();
597 info->ram->dirty_pages_rate = s->dirty_pages_rate;
598 info->ram->mbps = s->mbps;
599 info->ram->dirty_sync_count = s->dirty_sync_count;
600
601 if (blk_mig_active()) {
602 info->has_disk = true;
603 info->disk = g_malloc0(sizeof(*info->disk));
604 info->disk->transferred = blk_mig_bytes_transferred();
605 info->disk->remaining = blk_mig_bytes_remaining();
606 info->disk->total = blk_mig_bytes_total();
607 }
608
609 if (cpu_throttle_active()) {
610 info->has_cpu_throttle_percentage = true;
611 info->cpu_throttle_percentage = cpu_throttle_get_percentage();
612 }
613
614 get_xbzrle_cache_stats(info);
615 break;
616 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
617 /* Mostly the same as active; TODO add some postcopy stats */
618 info->has_status = true;
619 info->has_total_time = true;
620 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
621 - s->total_time;
622 info->has_expected_downtime = true;
623 info->expected_downtime = s->expected_downtime;
624 info->has_setup_time = true;
625 info->setup_time = s->setup_time;
626
627 info->has_ram = true;
628 info->ram = g_malloc0(sizeof(*info->ram));
629 info->ram->transferred = ram_bytes_transferred();
630 info->ram->remaining = ram_bytes_remaining();
631 info->ram->total = ram_bytes_total();
632 info->ram->duplicate = dup_mig_pages_transferred();
633 info->ram->skipped = skipped_mig_pages_transferred();
634 info->ram->normal = norm_mig_pages_transferred();
635 info->ram->normal_bytes = norm_mig_bytes_transferred();
636 info->ram->dirty_pages_rate = s->dirty_pages_rate;
637 info->ram->mbps = s->mbps;
638 info->ram->dirty_sync_count = s->dirty_sync_count;
639
640 if (blk_mig_active()) {
641 info->has_disk = true;
642 info->disk = g_malloc0(sizeof(*info->disk));
643 info->disk->transferred = blk_mig_bytes_transferred();
644 info->disk->remaining = blk_mig_bytes_remaining();
645 info->disk->total = blk_mig_bytes_total();
646 }
647
648 get_xbzrle_cache_stats(info);
649 break;
650 case MIGRATION_STATUS_COMPLETED:
651 get_xbzrle_cache_stats(info);
652
653 info->has_status = true;
654 info->has_total_time = true;
655 info->total_time = s->total_time;
656 info->has_downtime = true;
657 info->downtime = s->downtime;
658 info->has_setup_time = true;
659 info->setup_time = s->setup_time;
660
661 info->has_ram = true;
662 info->ram = g_malloc0(sizeof(*info->ram));
663 info->ram->transferred = ram_bytes_transferred();
664 info->ram->remaining = 0;
665 info->ram->total = ram_bytes_total();
666 info->ram->duplicate = dup_mig_pages_transferred();
667 info->ram->skipped = skipped_mig_pages_transferred();
668 info->ram->normal = norm_mig_pages_transferred();
669 info->ram->normal_bytes = norm_mig_bytes_transferred();
670 info->ram->mbps = s->mbps;
671 info->ram->dirty_sync_count = s->dirty_sync_count;
672 break;
673 case MIGRATION_STATUS_FAILED:
674 info->has_status = true;
675 break;
676 case MIGRATION_STATUS_CANCELLED:
677 info->has_status = true;
678 break;
679 }
680 info->status = s->state;
681
682 return info;
683 }
684
685 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
686 Error **errp)
687 {
688 MigrationState *s = migrate_get_current();
689 MigrationCapabilityStatusList *cap;
690
691 if (migration_is_setup_or_active(s->state)) {
692 error_setg(errp, QERR_MIGRATION_ACTIVE);
693 return;
694 }
695
696 for (cap = params; cap; cap = cap->next) {
697 s->enabled_capabilities[cap->value->capability] = cap->value->state;
698 }
699
700 if (migrate_postcopy_ram()) {
701 if (migrate_use_compression()) {
702 /* The decompression threads asynchronously write into RAM
703 * rather than use the atomic copies needed to avoid
704 * userfaulting. It should be possible to fix the decompression
705 * threads for compatibility in future.
706 */
707 error_report("Postcopy is not currently compatible with "
708 "compression");
709 s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] =
710 false;
711 }
712 }
713 }
714
715 void qmp_migrate_set_parameters(bool has_compress_level,
716 int64_t compress_level,
717 bool has_compress_threads,
718 int64_t compress_threads,
719 bool has_decompress_threads,
720 int64_t decompress_threads,
721 bool has_cpu_throttle_initial,
722 int64_t cpu_throttle_initial,
723 bool has_cpu_throttle_increment,
724 int64_t cpu_throttle_increment, Error **errp)
725 {
726 MigrationState *s = migrate_get_current();
727
728 if (has_compress_level && (compress_level < 0 || compress_level > 9)) {
729 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
730 "is invalid, it should be in the range of 0 to 9");
731 return;
732 }
733 if (has_compress_threads &&
734 (compress_threads < 1 || compress_threads > 255)) {
735 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
736 "compress_threads",
737 "is invalid, it should be in the range of 1 to 255");
738 return;
739 }
740 if (has_decompress_threads &&
741 (decompress_threads < 1 || decompress_threads > 255)) {
742 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
743 "decompress_threads",
744 "is invalid, it should be in the range of 1 to 255");
745 return;
746 }
747 if (has_cpu_throttle_initial &&
748 (cpu_throttle_initial < 1 || cpu_throttle_initial > 99)) {
749 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
750 "cpu_throttle_initial",
751 "an integer in the range of 1 to 99");
752 }
753 if (has_cpu_throttle_increment &&
754 (cpu_throttle_increment < 1 || cpu_throttle_increment > 99)) {
755 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
756 "cpu_throttle_increment",
757 "an integer in the range of 1 to 99");
758 }
759
760 if (has_compress_level) {
761 s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
762 }
763 if (has_compress_threads) {
764 s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads;
765 }
766 if (has_decompress_threads) {
767 s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
768 decompress_threads;
769 }
770 if (has_cpu_throttle_initial) {
771 s->parameters[MIGRATION_PARAMETER_CPU_THROTTLE_INITIAL] =
772 cpu_throttle_initial;
773 }
774
775 if (has_cpu_throttle_increment) {
776 s->parameters[MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT] =
777 cpu_throttle_increment;
778 }
779 }
780
781 void qmp_migrate_start_postcopy(Error **errp)
782 {
783 MigrationState *s = migrate_get_current();
784
785 if (!migrate_postcopy_ram()) {
786 error_setg(errp, "Enable postcopy with migrate_set_capability before"
787 " the start of migration");
788 return;
789 }
790
791 if (s->state == MIGRATION_STATUS_NONE) {
792 error_setg(errp, "Postcopy must be started after migration has been"
793 " started");
794 return;
795 }
796 /*
797 * we don't error if migration has finished since that would be racy
798 * with issuing this command.
799 */
800 atomic_set(&s->start_postcopy, true);
801 }
802
803 /* shared migration helpers */
804
805 void migrate_set_state(int *state, int old_state, int new_state)
806 {
807 if (atomic_cmpxchg(state, old_state, new_state) == old_state) {
808 trace_migrate_set_state(new_state);
809 migrate_generate_event(new_state);
810 }
811 }
812
813 static void migrate_fd_cleanup(void *opaque)
814 {
815 MigrationState *s = opaque;
816
817 qemu_bh_delete(s->cleanup_bh);
818 s->cleanup_bh = NULL;
819
820 flush_page_queue(s);
821
822 if (s->to_dst_file) {
823 trace_migrate_fd_cleanup();
824 qemu_mutex_unlock_iothread();
825 if (s->migration_thread_running) {
826 qemu_thread_join(&s->thread);
827 s->migration_thread_running = false;
828 }
829 qemu_mutex_lock_iothread();
830
831 migrate_compress_threads_join();
832 qemu_fclose(s->to_dst_file);
833 s->to_dst_file = NULL;
834 }
835
836 assert((s->state != MIGRATION_STATUS_ACTIVE) &&
837 (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE));
838
839 if (s->state == MIGRATION_STATUS_CANCELLING) {
840 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
841 MIGRATION_STATUS_CANCELLED);
842 }
843
844 notifier_list_notify(&migration_state_notifiers, s);
845 }
846
847 void migrate_fd_error(MigrationState *s)
848 {
849 trace_migrate_fd_error();
850 assert(s->to_dst_file == NULL);
851 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
852 MIGRATION_STATUS_FAILED);
853 notifier_list_notify(&migration_state_notifiers, s);
854 }
855
856 static void migrate_fd_cancel(MigrationState *s)
857 {
858 int old_state ;
859 QEMUFile *f = migrate_get_current()->to_dst_file;
860 trace_migrate_fd_cancel();
861
862 if (s->rp_state.from_dst_file) {
863 /* shutdown the rp socket, so causing the rp thread to shutdown */
864 qemu_file_shutdown(s->rp_state.from_dst_file);
865 }
866
867 do {
868 old_state = s->state;
869 if (!migration_is_setup_or_active(old_state)) {
870 break;
871 }
872 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
873 } while (s->state != MIGRATION_STATUS_CANCELLING);
874
875 /*
876 * If we're unlucky the migration code might be stuck somewhere in a
877 * send/write while the network has failed and is waiting to timeout;
878 * if we've got shutdown(2) available then we can force it to quit.
879 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
880 * called in a bh, so there is no race against this cancel.
881 */
882 if (s->state == MIGRATION_STATUS_CANCELLING && f) {
883 qemu_file_shutdown(f);
884 }
885 }
886
887 void add_migration_state_change_notifier(Notifier *notify)
888 {
889 notifier_list_add(&migration_state_notifiers, notify);
890 }
891
892 void remove_migration_state_change_notifier(Notifier *notify)
893 {
894 notifier_remove(notify);
895 }
896
897 bool migration_in_setup(MigrationState *s)
898 {
899 return s->state == MIGRATION_STATUS_SETUP;
900 }
901
902 bool migration_has_finished(MigrationState *s)
903 {
904 return s->state == MIGRATION_STATUS_COMPLETED;
905 }
906
907 bool migration_has_failed(MigrationState *s)
908 {
909 return (s->state == MIGRATION_STATUS_CANCELLED ||
910 s->state == MIGRATION_STATUS_FAILED);
911 }
912
913 bool migration_in_postcopy(MigrationState *s)
914 {
915 return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
916 }
917
918 bool migration_in_postcopy_after_devices(MigrationState *s)
919 {
920 return migration_in_postcopy(s) && s->postcopy_after_devices;
921 }
922
923 MigrationState *migrate_init(const MigrationParams *params)
924 {
925 MigrationState *s = migrate_get_current();
926
927 /*
928 * Reinitialise all migration state, except
929 * parameters/capabilities that the user set, and
930 * locks.
931 */
932 s->bytes_xfer = 0;
933 s->xfer_limit = 0;
934 s->cleanup_bh = 0;
935 s->to_dst_file = NULL;
936 s->state = MIGRATION_STATUS_NONE;
937 s->params = *params;
938 s->rp_state.from_dst_file = NULL;
939 s->rp_state.error = false;
940 s->mbps = 0.0;
941 s->downtime = 0;
942 s->expected_downtime = 0;
943 s->dirty_pages_rate = 0;
944 s->dirty_bytes_rate = 0;
945 s->setup_time = 0;
946 s->dirty_sync_count = 0;
947 s->start_postcopy = false;
948 s->postcopy_after_devices = false;
949 s->migration_thread_running = false;
950 s->last_req_rb = NULL;
951
952 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
953
954 QSIMPLEQ_INIT(&s->src_page_requests);
955
956 s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
957 return s;
958 }
959
960 static GSList *migration_blockers;
961
962 void migrate_add_blocker(Error *reason)
963 {
964 migration_blockers = g_slist_prepend(migration_blockers, reason);
965 }
966
967 void migrate_del_blocker(Error *reason)
968 {
969 migration_blockers = g_slist_remove(migration_blockers, reason);
970 }
971
972 void qmp_migrate_incoming(const char *uri, Error **errp)
973 {
974 Error *local_err = NULL;
975 static bool once = true;
976
977 if (!deferred_incoming) {
978 error_setg(errp, "For use with '-incoming defer'");
979 return;
980 }
981 if (!once) {
982 error_setg(errp, "The incoming migration has already been started");
983 }
984
985 qemu_start_incoming_migration(uri, &local_err);
986
987 if (local_err) {
988 error_propagate(errp, local_err);
989 return;
990 }
991
992 once = false;
993 }
994
995 bool migration_is_blocked(Error **errp)
996 {
997 if (qemu_savevm_state_blocked(errp)) {
998 return true;
999 }
1000
1001 if (migration_blockers) {
1002 *errp = error_copy(migration_blockers->data);
1003 return true;
1004 }
1005
1006 return false;
1007 }
1008
1009 void qmp_migrate(const char *uri, bool has_blk, bool blk,
1010 bool has_inc, bool inc, bool has_detach, bool detach,
1011 Error **errp)
1012 {
1013 Error *local_err = NULL;
1014 MigrationState *s = migrate_get_current();
1015 MigrationParams params;
1016 const char *p;
1017
1018 params.blk = has_blk && blk;
1019 params.shared = has_inc && inc;
1020
1021 if (migration_is_setup_or_active(s->state) ||
1022 s->state == MIGRATION_STATUS_CANCELLING) {
1023 error_setg(errp, QERR_MIGRATION_ACTIVE);
1024 return;
1025 }
1026 if (runstate_check(RUN_STATE_INMIGRATE)) {
1027 error_setg(errp, "Guest is waiting for an incoming migration");
1028 return;
1029 }
1030
1031 if (migration_is_blocked(errp)) {
1032 return;
1033 }
1034
1035 s = migrate_init(&params);
1036
1037 if (strstart(uri, "tcp:", &p)) {
1038 tcp_start_outgoing_migration(s, p, &local_err);
1039 #ifdef CONFIG_RDMA
1040 } else if (strstart(uri, "rdma:", &p)) {
1041 rdma_start_outgoing_migration(s, p, &local_err);
1042 #endif
1043 #if !defined(WIN32)
1044 } else if (strstart(uri, "exec:", &p)) {
1045 exec_start_outgoing_migration(s, p, &local_err);
1046 } else if (strstart(uri, "unix:", &p)) {
1047 unix_start_outgoing_migration(s, p, &local_err);
1048 } else if (strstart(uri, "fd:", &p)) {
1049 fd_start_outgoing_migration(s, p, &local_err);
1050 #endif
1051 } else {
1052 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
1053 "a valid migration protocol");
1054 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1055 MIGRATION_STATUS_FAILED);
1056 return;
1057 }
1058
1059 if (local_err) {
1060 migrate_fd_error(s);
1061 error_propagate(errp, local_err);
1062 return;
1063 }
1064 }
1065
1066 void qmp_migrate_cancel(Error **errp)
1067 {
1068 migrate_fd_cancel(migrate_get_current());
1069 }
1070
1071 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
1072 {
1073 MigrationState *s = migrate_get_current();
1074 int64_t new_size;
1075
1076 /* Check for truncation */
1077 if (value != (size_t)value) {
1078 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
1079 "exceeding address space");
1080 return;
1081 }
1082
1083 /* Cache should not be larger than guest ram size */
1084 if (value > ram_bytes_total()) {
1085 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
1086 "exceeds guest ram size ");
1087 return;
1088 }
1089
1090 new_size = xbzrle_cache_resize(value);
1091 if (new_size < 0) {
1092 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
1093 "is smaller than page size");
1094 return;
1095 }
1096
1097 s->xbzrle_cache_size = new_size;
1098 }
1099
1100 int64_t qmp_query_migrate_cache_size(Error **errp)
1101 {
1102 return migrate_xbzrle_cache_size();
1103 }
1104
1105 void qmp_migrate_set_speed(int64_t value, Error **errp)
1106 {
1107 MigrationState *s;
1108
1109 if (value < 0) {
1110 value = 0;
1111 }
1112 if (value > SIZE_MAX) {
1113 value = SIZE_MAX;
1114 }
1115
1116 s = migrate_get_current();
1117 s->bandwidth_limit = value;
1118 if (s->to_dst_file) {
1119 qemu_file_set_rate_limit(s->to_dst_file,
1120 s->bandwidth_limit / XFER_LIMIT_RATIO);
1121 }
1122 }
1123
1124 void qmp_migrate_set_downtime(double value, Error **errp)
1125 {
1126 value *= 1e9;
1127 value = MAX(0, MIN(UINT64_MAX, value));
1128 max_downtime = (uint64_t)value;
1129 }
1130
1131 bool migrate_postcopy_ram(void)
1132 {
1133 MigrationState *s;
1134
1135 s = migrate_get_current();
1136
1137 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM];
1138 }
1139
1140 bool migrate_auto_converge(void)
1141 {
1142 MigrationState *s;
1143
1144 s = migrate_get_current();
1145
1146 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
1147 }
1148
1149 bool migrate_zero_blocks(void)
1150 {
1151 MigrationState *s;
1152
1153 s = migrate_get_current();
1154
1155 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
1156 }
1157
1158 bool migrate_use_compression(void)
1159 {
1160 MigrationState *s;
1161
1162 s = migrate_get_current();
1163
1164 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
1165 }
1166
1167 int migrate_compress_level(void)
1168 {
1169 MigrationState *s;
1170
1171 s = migrate_get_current();
1172
1173 return s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
1174 }
1175
1176 int migrate_compress_threads(void)
1177 {
1178 MigrationState *s;
1179
1180 s = migrate_get_current();
1181
1182 return s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
1183 }
1184
1185 int migrate_decompress_threads(void)
1186 {
1187 MigrationState *s;
1188
1189 s = migrate_get_current();
1190
1191 return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
1192 }
1193
1194 bool migrate_use_events(void)
1195 {
1196 MigrationState *s;
1197
1198 s = migrate_get_current();
1199
1200 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
1201 }
1202
1203 int migrate_use_xbzrle(void)
1204 {
1205 MigrationState *s;
1206
1207 s = migrate_get_current();
1208
1209 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
1210 }
1211
1212 int64_t migrate_xbzrle_cache_size(void)
1213 {
1214 MigrationState *s;
1215
1216 s = migrate_get_current();
1217
1218 return s->xbzrle_cache_size;
1219 }
1220
1221 /* migration thread support */
1222 /*
1223 * Something bad happened to the RP stream, mark an error
1224 * The caller shall print or trace something to indicate why
1225 */
1226 static void mark_source_rp_bad(MigrationState *s)
1227 {
1228 s->rp_state.error = true;
1229 }
1230
1231 static struct rp_cmd_args {
1232 ssize_t len; /* -1 = variable */
1233 const char *name;
1234 } rp_cmd_args[] = {
1235 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
1236 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
1237 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
1238 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
1239 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
1240 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
1241 };
1242
1243 /*
1244 * Process a request for pages received on the return path,
1245 * We're allowed to send more than requested (e.g. to round to our page size)
1246 * and we don't need to send pages that have already been sent.
1247 */
1248 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
1249 ram_addr_t start, size_t len)
1250 {
1251 long our_host_ps = getpagesize();
1252
1253 trace_migrate_handle_rp_req_pages(rbname, start, len);
1254
1255 /*
1256 * Since we currently insist on matching page sizes, just sanity check
1257 * we're being asked for whole host pages.
1258 */
1259 if (start & (our_host_ps-1) ||
1260 (len & (our_host_ps-1))) {
1261 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
1262 " len: %zd", __func__, start, len);
1263 mark_source_rp_bad(ms);
1264 return;
1265 }
1266
1267 if (ram_save_queue_pages(ms, rbname, start, len)) {
1268 mark_source_rp_bad(ms);
1269 }
1270 }
1271
1272 /*
1273 * Handles messages sent on the return path towards the source VM
1274 *
1275 */
1276 static void *source_return_path_thread(void *opaque)
1277 {
1278 MigrationState *ms = opaque;
1279 QEMUFile *rp = ms->rp_state.from_dst_file;
1280 uint16_t header_len, header_type;
1281 uint8_t buf[512];
1282 uint32_t tmp32, sibling_error;
1283 ram_addr_t start = 0; /* =0 to silence warning */
1284 size_t len = 0, expected_len;
1285 int res;
1286
1287 trace_source_return_path_thread_entry();
1288 while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
1289 migration_is_setup_or_active(ms->state)) {
1290 trace_source_return_path_thread_loop_top();
1291 header_type = qemu_get_be16(rp);
1292 header_len = qemu_get_be16(rp);
1293
1294 if (header_type >= MIG_RP_MSG_MAX ||
1295 header_type == MIG_RP_MSG_INVALID) {
1296 error_report("RP: Received invalid message 0x%04x length 0x%04x",
1297 header_type, header_len);
1298 mark_source_rp_bad(ms);
1299 goto out;
1300 }
1301
1302 if ((rp_cmd_args[header_type].len != -1 &&
1303 header_len != rp_cmd_args[header_type].len) ||
1304 header_len > sizeof(buf)) {
1305 error_report("RP: Received '%s' message (0x%04x) with"
1306 "incorrect length %d expecting %zu",
1307 rp_cmd_args[header_type].name, header_type, header_len,
1308 (size_t)rp_cmd_args[header_type].len);
1309 mark_source_rp_bad(ms);
1310 goto out;
1311 }
1312
1313 /* We know we've got a valid header by this point */
1314 res = qemu_get_buffer(rp, buf, header_len);
1315 if (res != header_len) {
1316 error_report("RP: Failed reading data for message 0x%04x"
1317 " read %d expected %d",
1318 header_type, res, header_len);
1319 mark_source_rp_bad(ms);
1320 goto out;
1321 }
1322
1323 /* OK, we have the message and the data */
1324 switch (header_type) {
1325 case MIG_RP_MSG_SHUT:
1326 sibling_error = be32_to_cpup((uint32_t *)buf);
1327 trace_source_return_path_thread_shut(sibling_error);
1328 if (sibling_error) {
1329 error_report("RP: Sibling indicated error %d", sibling_error);
1330 mark_source_rp_bad(ms);
1331 }
1332 /*
1333 * We'll let the main thread deal with closing the RP
1334 * we could do a shutdown(2) on it, but we're the only user
1335 * anyway, so there's nothing gained.
1336 */
1337 goto out;
1338
1339 case MIG_RP_MSG_PONG:
1340 tmp32 = be32_to_cpup((uint32_t *)buf);
1341 trace_source_return_path_thread_pong(tmp32);
1342 break;
1343
1344 case MIG_RP_MSG_REQ_PAGES:
1345 start = be64_to_cpup((uint64_t *)buf);
1346 len = be32_to_cpup((uint32_t *)(buf + 8));
1347 migrate_handle_rp_req_pages(ms, NULL, start, len);
1348 break;
1349
1350 case MIG_RP_MSG_REQ_PAGES_ID:
1351 expected_len = 12 + 1; /* header + termination */
1352
1353 if (header_len >= expected_len) {
1354 start = be64_to_cpup((uint64_t *)buf);
1355 len = be32_to_cpup((uint32_t *)(buf + 8));
1356 /* Now we expect an idstr */
1357 tmp32 = buf[12]; /* Length of the following idstr */
1358 buf[13 + tmp32] = '\0';
1359 expected_len += tmp32;
1360 }
1361 if (header_len != expected_len) {
1362 error_report("RP: Req_Page_id with length %d expecting %zd",
1363 header_len, expected_len);
1364 mark_source_rp_bad(ms);
1365 goto out;
1366 }
1367 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
1368 break;
1369
1370 default:
1371 break;
1372 }
1373 }
1374 if (qemu_file_get_error(rp)) {
1375 trace_source_return_path_thread_bad_end();
1376 mark_source_rp_bad(ms);
1377 }
1378
1379 trace_source_return_path_thread_end();
1380 out:
1381 ms->rp_state.from_dst_file = NULL;
1382 qemu_fclose(rp);
1383 return NULL;
1384 }
1385
1386 static int open_return_path_on_source(MigrationState *ms)
1387 {
1388
1389 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
1390 if (!ms->rp_state.from_dst_file) {
1391 return -1;
1392 }
1393
1394 trace_open_return_path_on_source();
1395 qemu_thread_create(&ms->rp_state.rp_thread, "return path",
1396 source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
1397
1398 trace_open_return_path_on_source_continue();
1399
1400 return 0;
1401 }
1402
1403 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1404 static int await_return_path_close_on_source(MigrationState *ms)
1405 {
1406 /*
1407 * If this is a normal exit then the destination will send a SHUT and the
1408 * rp_thread will exit, however if there's an error we need to cause
1409 * it to exit.
1410 */
1411 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) {
1412 /*
1413 * shutdown(2), if we have it, will cause it to unblock if it's stuck
1414 * waiting for the destination.
1415 */
1416 qemu_file_shutdown(ms->rp_state.from_dst_file);
1417 mark_source_rp_bad(ms);
1418 }
1419 trace_await_return_path_close_on_source_joining();
1420 qemu_thread_join(&ms->rp_state.rp_thread);
1421 trace_await_return_path_close_on_source_close();
1422 return ms->rp_state.error;
1423 }
1424
1425 /*
1426 * Switch from normal iteration to postcopy
1427 * Returns non-0 on error
1428 */
1429 static int postcopy_start(MigrationState *ms, bool *old_vm_running)
1430 {
1431 int ret;
1432 const QEMUSizedBuffer *qsb;
1433 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1434 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
1435 MIGRATION_STATUS_POSTCOPY_ACTIVE);
1436
1437 trace_postcopy_start();
1438 qemu_mutex_lock_iothread();
1439 trace_postcopy_start_set_run();
1440
1441 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
1442 *old_vm_running = runstate_is_running();
1443 global_state_store();
1444 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
1445 if (ret < 0) {
1446 goto fail;
1447 }
1448
1449 ret = bdrv_inactivate_all();
1450 if (ret < 0) {
1451 goto fail;
1452 }
1453
1454 /*
1455 * Cause any non-postcopiable, but iterative devices to
1456 * send out their final data.
1457 */
1458 qemu_savevm_state_complete_precopy(ms->to_dst_file, true);
1459
1460 /*
1461 * in Finish migrate and with the io-lock held everything should
1462 * be quiet, but we've potentially still got dirty pages and we
1463 * need to tell the destination to throw any pages it's already received
1464 * that are dirty
1465 */
1466 if (ram_postcopy_send_discard_bitmap(ms)) {
1467 error_report("postcopy send discard bitmap failed");
1468 goto fail;
1469 }
1470
1471 /*
1472 * send rest of state - note things that are doing postcopy
1473 * will notice we're in POSTCOPY_ACTIVE and not actually
1474 * wrap their state up here
1475 */
1476 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);
1477 /* Ping just for debugging, helps line traces up */
1478 qemu_savevm_send_ping(ms->to_dst_file, 2);
1479
1480 /*
1481 * While loading the device state we may trigger page transfer
1482 * requests and the fd must be free to process those, and thus
1483 * the destination must read the whole device state off the fd before
1484 * it starts processing it. Unfortunately the ad-hoc migration format
1485 * doesn't allow the destination to know the size to read without fully
1486 * parsing it through each devices load-state code (especially the open
1487 * coded devices that use get/put).
1488 * So we wrap the device state up in a package with a length at the start;
1489 * to do this we use a qemu_buf to hold the whole of the device state.
1490 */
1491 QEMUFile *fb = qemu_bufopen("w", NULL);
1492 if (!fb) {
1493 error_report("Failed to create buffered file");
1494 goto fail;
1495 }
1496
1497 /*
1498 * Make sure the receiver can get incoming pages before we send the rest
1499 * of the state
1500 */
1501 qemu_savevm_send_postcopy_listen(fb);
1502
1503 qemu_savevm_state_complete_precopy(fb, false);
1504 qemu_savevm_send_ping(fb, 3);
1505
1506 qemu_savevm_send_postcopy_run(fb);
1507
1508 /* <><> end of stuff going into the package */
1509 qsb = qemu_buf_get(fb);
1510
1511 /* Now send that blob */
1512 if (qemu_savevm_send_packaged(ms->to_dst_file, qsb)) {
1513 goto fail_closefb;
1514 }
1515 qemu_fclose(fb);
1516
1517 /* Send a notify to give a chance for anything that needs to happen
1518 * at the transition to postcopy and after the device state; in particular
1519 * spice needs to trigger a transition now
1520 */
1521 ms->postcopy_after_devices = true;
1522 notifier_list_notify(&migration_state_notifiers, ms);
1523
1524 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
1525
1526 qemu_mutex_unlock_iothread();
1527
1528 /*
1529 * Although this ping is just for debug, it could potentially be
1530 * used for getting a better measurement of downtime at the source.
1531 */
1532 qemu_savevm_send_ping(ms->to_dst_file, 4);
1533
1534 ret = qemu_file_get_error(ms->to_dst_file);
1535 if (ret) {
1536 error_report("postcopy_start: Migration stream errored");
1537 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1538 MIGRATION_STATUS_FAILED);
1539 }
1540
1541 return ret;
1542
1543 fail_closefb:
1544 qemu_fclose(fb);
1545 fail:
1546 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1547 MIGRATION_STATUS_FAILED);
1548 qemu_mutex_unlock_iothread();
1549 return -1;
1550 }
1551
1552 /**
1553 * migration_completion: Used by migration_thread when there's not much left.
1554 * The caller 'breaks' the loop when this returns.
1555 *
1556 * @s: Current migration state
1557 * @current_active_state: The migration state we expect to be in
1558 * @*old_vm_running: Pointer to old_vm_running flag
1559 * @*start_time: Pointer to time to update
1560 */
1561 static void migration_completion(MigrationState *s, int current_active_state,
1562 bool *old_vm_running,
1563 int64_t *start_time)
1564 {
1565 int ret;
1566
1567 if (s->state == MIGRATION_STATUS_ACTIVE) {
1568 qemu_mutex_lock_iothread();
1569 *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1570 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
1571 *old_vm_running = runstate_is_running();
1572 ret = global_state_store();
1573
1574 if (!ret) {
1575 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
1576 if (ret >= 0) {
1577 ret = bdrv_inactivate_all();
1578 }
1579 if (ret >= 0) {
1580 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
1581 qemu_savevm_state_complete_precopy(s->to_dst_file, false);
1582 }
1583 }
1584 qemu_mutex_unlock_iothread();
1585
1586 if (ret < 0) {
1587 goto fail;
1588 }
1589 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
1590 trace_migration_completion_postcopy_end();
1591
1592 qemu_savevm_state_complete_postcopy(s->to_dst_file);
1593 trace_migration_completion_postcopy_end_after_complete();
1594 }
1595
1596 /*
1597 * If rp was opened we must clean up the thread before
1598 * cleaning everything else up (since if there are no failures
1599 * it will wait for the destination to send it's status in
1600 * a SHUT command).
1601 * Postcopy opens rp if enabled (even if it's not avtivated)
1602 */
1603 if (migrate_postcopy_ram()) {
1604 int rp_error;
1605 trace_migration_completion_postcopy_end_before_rp();
1606 rp_error = await_return_path_close_on_source(s);
1607 trace_migration_completion_postcopy_end_after_rp(rp_error);
1608 if (rp_error) {
1609 goto fail_invalidate;
1610 }
1611 }
1612
1613 if (qemu_file_get_error(s->to_dst_file)) {
1614 trace_migration_completion_file_err();
1615 goto fail_invalidate;
1616 }
1617
1618 migrate_set_state(&s->state, current_active_state,
1619 MIGRATION_STATUS_COMPLETED);
1620 return;
1621
1622 fail_invalidate:
1623 /* If not doing postcopy, vm_start() will be called: let's regain
1624 * control on images.
1625 */
1626 if (s->state == MIGRATION_STATUS_ACTIVE) {
1627 Error *local_err = NULL;
1628
1629 bdrv_invalidate_cache_all(&local_err);
1630 if (local_err) {
1631 error_report_err(local_err);
1632 }
1633 }
1634
1635 fail:
1636 migrate_set_state(&s->state, current_active_state,
1637 MIGRATION_STATUS_FAILED);
1638 }
1639
1640 /*
1641 * Master migration thread on the source VM.
1642 * It drives the migration and pumps the data down the outgoing channel.
1643 */
1644 static void *migration_thread(void *opaque)
1645 {
1646 MigrationState *s = opaque;
1647 /* Used by the bandwidth calcs, updated later */
1648 int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1649 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
1650 int64_t initial_bytes = 0;
1651 int64_t max_size = 0;
1652 int64_t start_time = initial_time;
1653 int64_t end_time;
1654 bool old_vm_running = false;
1655 bool entered_postcopy = false;
1656 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
1657 enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
1658
1659 rcu_register_thread();
1660
1661 qemu_savevm_state_header(s->to_dst_file);
1662
1663 if (migrate_postcopy_ram()) {
1664 /* Now tell the dest that it should open its end so it can reply */
1665 qemu_savevm_send_open_return_path(s->to_dst_file);
1666
1667 /* And do a ping that will make stuff easier to debug */
1668 qemu_savevm_send_ping(s->to_dst_file, 1);
1669
1670 /*
1671 * Tell the destination that we *might* want to do postcopy later;
1672 * if the other end can't do postcopy it should fail now, nice and
1673 * early.
1674 */
1675 qemu_savevm_send_postcopy_advise(s->to_dst_file);
1676 }
1677
1678 qemu_savevm_state_begin(s->to_dst_file, &s->params);
1679
1680 s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
1681 current_active_state = MIGRATION_STATUS_ACTIVE;
1682 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1683 MIGRATION_STATUS_ACTIVE);
1684
1685 trace_migration_thread_setup_complete();
1686
1687 while (s->state == MIGRATION_STATUS_ACTIVE ||
1688 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
1689 int64_t current_time;
1690 uint64_t pending_size;
1691
1692 if (!qemu_file_rate_limit(s->to_dst_file)) {
1693 uint64_t pend_post, pend_nonpost;
1694
1695 qemu_savevm_state_pending(s->to_dst_file, max_size, &pend_nonpost,
1696 &pend_post);
1697 pending_size = pend_nonpost + pend_post;
1698 trace_migrate_pending(pending_size, max_size,
1699 pend_post, pend_nonpost);
1700 if (pending_size && pending_size >= max_size) {
1701 /* Still a significant amount to transfer */
1702
1703 if (migrate_postcopy_ram() &&
1704 s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE &&
1705 pend_nonpost <= max_size &&
1706 atomic_read(&s->start_postcopy)) {
1707
1708 if (!postcopy_start(s, &old_vm_running)) {
1709 current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE;
1710 entered_postcopy = true;
1711 }
1712
1713 continue;
1714 }
1715 /* Just another iteration step */
1716 qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy);
1717 } else {
1718 trace_migration_thread_low_pending(pending_size);
1719 migration_completion(s, current_active_state,
1720 &old_vm_running, &start_time);
1721 break;
1722 }
1723 }
1724
1725 if (qemu_file_get_error(s->to_dst_file)) {
1726 migrate_set_state(&s->state, current_active_state,
1727 MIGRATION_STATUS_FAILED);
1728 trace_migration_thread_file_err();
1729 break;
1730 }
1731 current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1732 if (current_time >= initial_time + BUFFER_DELAY) {
1733 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file) -
1734 initial_bytes;
1735 uint64_t time_spent = current_time - initial_time;
1736 double bandwidth = (double)transferred_bytes / time_spent;
1737 max_size = bandwidth * migrate_max_downtime() / 1000000;
1738
1739 s->mbps = (((double) transferred_bytes * 8.0) /
1740 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
1741
1742 trace_migrate_transferred(transferred_bytes, time_spent,
1743 bandwidth, max_size);
1744 /* if we haven't sent anything, we don't want to recalculate
1745 10000 is a small enough number for our purposes */
1746 if (s->dirty_bytes_rate && transferred_bytes > 10000) {
1747 s->expected_downtime = s->dirty_bytes_rate / bandwidth;
1748 }
1749
1750 qemu_file_reset_rate_limit(s->to_dst_file);
1751 initial_time = current_time;
1752 initial_bytes = qemu_ftell(s->to_dst_file);
1753 }
1754 if (qemu_file_rate_limit(s->to_dst_file)) {
1755 /* usleep expects microseconds */
1756 g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
1757 }
1758 }
1759
1760 trace_migration_thread_after_loop();
1761 /* If we enabled cpu throttling for auto-converge, turn it off. */
1762 cpu_throttle_stop();
1763 end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1764
1765 qemu_mutex_lock_iothread();
1766 qemu_savevm_state_cleanup();
1767 if (s->state == MIGRATION_STATUS_COMPLETED) {
1768 uint64_t transferred_bytes = qemu_ftell(s->to_dst_file);
1769 s->total_time = end_time - s->total_time;
1770 if (!entered_postcopy) {
1771 s->downtime = end_time - start_time;
1772 }
1773 if (s->total_time) {
1774 s->mbps = (((double) transferred_bytes * 8.0) /
1775 ((double) s->total_time)) / 1000;
1776 }
1777 runstate_set(RUN_STATE_POSTMIGRATE);
1778 } else {
1779 if (old_vm_running && !entered_postcopy) {
1780 vm_start();
1781 }
1782 }
1783 qemu_bh_schedule(s->cleanup_bh);
1784 qemu_mutex_unlock_iothread();
1785
1786 rcu_unregister_thread();
1787 return NULL;
1788 }
1789
1790 void migrate_fd_connect(MigrationState *s)
1791 {
1792 /* This is a best 1st approximation. ns to ms */
1793 s->expected_downtime = max_downtime/1000000;
1794 s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
1795
1796 qemu_file_set_rate_limit(s->to_dst_file,
1797 s->bandwidth_limit / XFER_LIMIT_RATIO);
1798
1799 /* Notify before starting migration thread */
1800 notifier_list_notify(&migration_state_notifiers, s);
1801
1802 /*
1803 * Open the return path; currently for postcopy but other things might
1804 * also want it.
1805 */
1806 if (migrate_postcopy_ram()) {
1807 if (open_return_path_on_source(s)) {
1808 error_report("Unable to open return-path for postcopy");
1809 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1810 MIGRATION_STATUS_FAILED);
1811 migrate_fd_cleanup(s);
1812 return;
1813 }
1814 }
1815
1816 migrate_compress_threads_create();
1817 qemu_thread_create(&s->thread, "migration", migration_thread, s,
1818 QEMU_THREAD_JOINABLE);
1819 s->migration_thread_running = true;
1820 }
1821
1822 PostcopyState postcopy_state_get(void)
1823 {
1824 return atomic_mb_read(&incoming_postcopy_state);
1825 }
1826
1827 /* Set the state and return the old state */
1828 PostcopyState postcopy_state_set(PostcopyState new_state)
1829 {
1830 return atomic_xchg(&incoming_postcopy_state, new_state);
1831 }
1832