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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-common.h" | |
17 | #include "migration.h" | |
18 | #include "monitor.h" | |
19 | #include "buffered_file.h" | |
20 | #include "sysemu.h" | |
21 | #include "block.h" | |
22 | #include "qemu_socket.h" | |
23 | #include "block-migration.h" | |
24 | #include "qmp-commands.h" | |
25 | ||
26 | //#define DEBUG_MIGRATION | |
27 | ||
28 | #ifdef DEBUG_MIGRATION | |
29 | #define DPRINTF(fmt, ...) \ | |
30 | do { printf("migration: " fmt, ## __VA_ARGS__); } while (0) | |
31 | #else | |
32 | #define DPRINTF(fmt, ...) \ | |
33 | do { } while (0) | |
34 | #endif | |
35 | ||
36 | enum { | |
37 | MIG_STATE_ERROR, | |
38 | MIG_STATE_SETUP, | |
39 | MIG_STATE_CANCELLED, | |
40 | MIG_STATE_ACTIVE, | |
41 | MIG_STATE_COMPLETED, | |
42 | }; | |
43 | ||
44 | #define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ | |
45 | ||
46 | /* Migration XBZRLE default cache size */ | |
47 | #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) | |
48 | ||
49 | static NotifierList migration_state_notifiers = | |
50 | NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); | |
51 | ||
52 | /* When we add fault tolerance, we could have several | |
53 | migrations at once. For now we don't need to add | |
54 | dynamic creation of migration */ | |
55 | ||
56 | MigrationState *migrate_get_current(void) | |
57 | { | |
58 | static MigrationState current_migration = { | |
59 | .state = MIG_STATE_SETUP, | |
60 | .bandwidth_limit = MAX_THROTTLE, | |
61 | .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE, | |
62 | }; | |
63 | ||
64 | return ¤t_migration; | |
65 | } | |
66 | ||
67 | void qemu_start_incoming_migration(const char *uri, Error **errp) | |
68 | { | |
69 | const char *p; | |
70 | ||
71 | if (strstart(uri, "tcp:", &p)) | |
72 | tcp_start_incoming_migration(p, errp); | |
73 | #if !defined(WIN32) | |
74 | else if (strstart(uri, "exec:", &p)) | |
75 | exec_start_incoming_migration(p, errp); | |
76 | else if (strstart(uri, "unix:", &p)) | |
77 | unix_start_incoming_migration(p, errp); | |
78 | else if (strstart(uri, "fd:", &p)) | |
79 | fd_start_incoming_migration(p, errp); | |
80 | #endif | |
81 | else { | |
82 | error_setg(errp, "unknown migration protocol: %s\n", uri); | |
83 | } | |
84 | } | |
85 | ||
86 | static void process_incoming_migration_co(void *opaque) | |
87 | { | |
88 | QEMUFile *f = opaque; | |
89 | int ret; | |
90 | ||
91 | ret = qemu_loadvm_state(f); | |
92 | qemu_set_fd_handler(qemu_get_fd(f), NULL, NULL, NULL); | |
93 | qemu_fclose(f); | |
94 | if (ret < 0) { | |
95 | fprintf(stderr, "load of migration failed\n"); | |
96 | exit(0); | |
97 | } | |
98 | qemu_announce_self(); | |
99 | DPRINTF("successfully loaded vm state\n"); | |
100 | ||
101 | bdrv_clear_incoming_migration_all(); | |
102 | /* Make sure all file formats flush their mutable metadata */ | |
103 | bdrv_invalidate_cache_all(); | |
104 | ||
105 | if (autostart) { | |
106 | vm_start(); | |
107 | } else { | |
108 | runstate_set(RUN_STATE_PAUSED); | |
109 | } | |
110 | } | |
111 | ||
112 | static void enter_migration_coroutine(void *opaque) | |
113 | { | |
114 | Coroutine *co = opaque; | |
115 | qemu_coroutine_enter(co, NULL); | |
116 | } | |
117 | ||
118 | void process_incoming_migration(QEMUFile *f) | |
119 | { | |
120 | Coroutine *co = qemu_coroutine_create(process_incoming_migration_co); | |
121 | int fd = qemu_get_fd(f); | |
122 | ||
123 | assert(fd != -1); | |
124 | socket_set_nonblock(fd); | |
125 | qemu_set_fd_handler(fd, enter_migration_coroutine, NULL, co); | |
126 | qemu_coroutine_enter(co, f); | |
127 | } | |
128 | ||
129 | /* amount of nanoseconds we are willing to wait for migration to be down. | |
130 | * the choice of nanoseconds is because it is the maximum resolution that | |
131 | * get_clock() can achieve. It is an internal measure. All user-visible | |
132 | * units must be in seconds */ | |
133 | static uint64_t max_downtime = 30000000; | |
134 | ||
135 | uint64_t migrate_max_downtime(void) | |
136 | { | |
137 | return max_downtime; | |
138 | } | |
139 | ||
140 | MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) | |
141 | { | |
142 | MigrationCapabilityStatusList *head = NULL; | |
143 | MigrationCapabilityStatusList *caps; | |
144 | MigrationState *s = migrate_get_current(); | |
145 | int i; | |
146 | ||
147 | for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) { | |
148 | if (head == NULL) { | |
149 | head = g_malloc0(sizeof(*caps)); | |
150 | caps = head; | |
151 | } else { | |
152 | caps->next = g_malloc0(sizeof(*caps)); | |
153 | caps = caps->next; | |
154 | } | |
155 | caps->value = | |
156 | g_malloc(sizeof(*caps->value)); | |
157 | caps->value->capability = i; | |
158 | caps->value->state = s->enabled_capabilities[i]; | |
159 | } | |
160 | ||
161 | return head; | |
162 | } | |
163 | ||
164 | static void get_xbzrle_cache_stats(MigrationInfo *info) | |
165 | { | |
166 | if (migrate_use_xbzrle()) { | |
167 | info->has_xbzrle_cache = true; | |
168 | info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); | |
169 | info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); | |
170 | info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred(); | |
171 | info->xbzrle_cache->pages = xbzrle_mig_pages_transferred(); | |
172 | info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss(); | |
173 | info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow(); | |
174 | } | |
175 | } | |
176 | ||
177 | MigrationInfo *qmp_query_migrate(Error **errp) | |
178 | { | |
179 | MigrationInfo *info = g_malloc0(sizeof(*info)); | |
180 | MigrationState *s = migrate_get_current(); | |
181 | ||
182 | switch (s->state) { | |
183 | case MIG_STATE_SETUP: | |
184 | /* no migration has happened ever */ | |
185 | break; | |
186 | case MIG_STATE_ACTIVE: | |
187 | info->has_status = true; | |
188 | info->status = g_strdup("active"); | |
189 | info->has_total_time = true; | |
190 | info->total_time = qemu_get_clock_ms(rt_clock) | |
191 | - s->total_time; | |
192 | info->has_expected_downtime = true; | |
193 | info->expected_downtime = s->expected_downtime; | |
194 | ||
195 | info->has_ram = true; | |
196 | info->ram = g_malloc0(sizeof(*info->ram)); | |
197 | info->ram->transferred = ram_bytes_transferred(); | |
198 | info->ram->remaining = ram_bytes_remaining(); | |
199 | info->ram->total = ram_bytes_total(); | |
200 | info->ram->duplicate = dup_mig_pages_transferred(); | |
201 | info->ram->normal = norm_mig_pages_transferred(); | |
202 | info->ram->normal_bytes = norm_mig_bytes_transferred(); | |
203 | info->ram->dirty_pages_rate = s->dirty_pages_rate; | |
204 | ||
205 | ||
206 | if (blk_mig_active()) { | |
207 | info->has_disk = true; | |
208 | info->disk = g_malloc0(sizeof(*info->disk)); | |
209 | info->disk->transferred = blk_mig_bytes_transferred(); | |
210 | info->disk->remaining = blk_mig_bytes_remaining(); | |
211 | info->disk->total = blk_mig_bytes_total(); | |
212 | } | |
213 | ||
214 | get_xbzrle_cache_stats(info); | |
215 | break; | |
216 | case MIG_STATE_COMPLETED: | |
217 | get_xbzrle_cache_stats(info); | |
218 | ||
219 | info->has_status = true; | |
220 | info->status = g_strdup("completed"); | |
221 | info->total_time = s->total_time; | |
222 | info->has_downtime = true; | |
223 | info->downtime = s->downtime; | |
224 | ||
225 | info->has_ram = true; | |
226 | info->ram = g_malloc0(sizeof(*info->ram)); | |
227 | info->ram->transferred = ram_bytes_transferred(); | |
228 | info->ram->remaining = 0; | |
229 | info->ram->total = ram_bytes_total(); | |
230 | info->ram->duplicate = dup_mig_pages_transferred(); | |
231 | info->ram->normal = norm_mig_pages_transferred(); | |
232 | info->ram->normal_bytes = norm_mig_bytes_transferred(); | |
233 | break; | |
234 | case MIG_STATE_ERROR: | |
235 | info->has_status = true; | |
236 | info->status = g_strdup("failed"); | |
237 | break; | |
238 | case MIG_STATE_CANCELLED: | |
239 | info->has_status = true; | |
240 | info->status = g_strdup("cancelled"); | |
241 | break; | |
242 | } | |
243 | ||
244 | return info; | |
245 | } | |
246 | ||
247 | void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, | |
248 | Error **errp) | |
249 | { | |
250 | MigrationState *s = migrate_get_current(); | |
251 | MigrationCapabilityStatusList *cap; | |
252 | ||
253 | if (s->state == MIG_STATE_ACTIVE) { | |
254 | error_set(errp, QERR_MIGRATION_ACTIVE); | |
255 | return; | |
256 | } | |
257 | ||
258 | for (cap = params; cap; cap = cap->next) { | |
259 | s->enabled_capabilities[cap->value->capability] = cap->value->state; | |
260 | } | |
261 | } | |
262 | ||
263 | /* shared migration helpers */ | |
264 | ||
265 | static int migrate_fd_cleanup(MigrationState *s) | |
266 | { | |
267 | int ret = 0; | |
268 | ||
269 | if (s->file) { | |
270 | DPRINTF("closing file\n"); | |
271 | ret = qemu_fclose(s->file); | |
272 | s->file = NULL; | |
273 | } | |
274 | ||
275 | migrate_fd_close(s); | |
276 | return ret; | |
277 | } | |
278 | ||
279 | void migrate_fd_error(MigrationState *s) | |
280 | { | |
281 | DPRINTF("setting error state\n"); | |
282 | s->state = MIG_STATE_ERROR; | |
283 | notifier_list_notify(&migration_state_notifiers, s); | |
284 | migrate_fd_cleanup(s); | |
285 | } | |
286 | ||
287 | static void migrate_fd_completed(MigrationState *s) | |
288 | { | |
289 | DPRINTF("setting completed state\n"); | |
290 | if (migrate_fd_cleanup(s) < 0) { | |
291 | s->state = MIG_STATE_ERROR; | |
292 | } else { | |
293 | s->state = MIG_STATE_COMPLETED; | |
294 | runstate_set(RUN_STATE_POSTMIGRATE); | |
295 | } | |
296 | notifier_list_notify(&migration_state_notifiers, s); | |
297 | } | |
298 | ||
299 | static void migrate_fd_put_notify(void *opaque) | |
300 | { | |
301 | MigrationState *s = opaque; | |
302 | int ret; | |
303 | ||
304 | qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); | |
305 | ret = qemu_file_put_notify(s->file); | |
306 | if (ret) { | |
307 | migrate_fd_error(s); | |
308 | } | |
309 | } | |
310 | ||
311 | ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data, | |
312 | size_t size) | |
313 | { | |
314 | ssize_t ret; | |
315 | ||
316 | if (s->state != MIG_STATE_ACTIVE) { | |
317 | return -EIO; | |
318 | } | |
319 | ||
320 | do { | |
321 | ret = s->write(s, data, size); | |
322 | } while (ret == -1 && ((s->get_error(s)) == EINTR)); | |
323 | ||
324 | if (ret == -1) | |
325 | ret = -(s->get_error(s)); | |
326 | ||
327 | if (ret == -EAGAIN) { | |
328 | qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s); | |
329 | } | |
330 | ||
331 | return ret; | |
332 | } | |
333 | ||
334 | void migrate_fd_put_ready(MigrationState *s) | |
335 | { | |
336 | int ret; | |
337 | ||
338 | if (s->state != MIG_STATE_ACTIVE) { | |
339 | DPRINTF("put_ready returning because of non-active state\n"); | |
340 | return; | |
341 | } | |
342 | ||
343 | DPRINTF("iterate\n"); | |
344 | ret = qemu_savevm_state_iterate(s->file); | |
345 | if (ret < 0) { | |
346 | migrate_fd_error(s); | |
347 | } else if (ret == 1) { | |
348 | int old_vm_running = runstate_is_running(); | |
349 | int64_t start_time, end_time; | |
350 | ||
351 | DPRINTF("done iterating\n"); | |
352 | start_time = qemu_get_clock_ms(rt_clock); | |
353 | qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); | |
354 | vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); | |
355 | ||
356 | if (qemu_savevm_state_complete(s->file) < 0) { | |
357 | migrate_fd_error(s); | |
358 | } else { | |
359 | migrate_fd_completed(s); | |
360 | } | |
361 | end_time = qemu_get_clock_ms(rt_clock); | |
362 | s->total_time = end_time - s->total_time; | |
363 | s->downtime = end_time - start_time; | |
364 | if (s->state != MIG_STATE_COMPLETED) { | |
365 | if (old_vm_running) { | |
366 | vm_start(); | |
367 | } | |
368 | } | |
369 | } | |
370 | } | |
371 | ||
372 | static void migrate_fd_cancel(MigrationState *s) | |
373 | { | |
374 | if (s->state != MIG_STATE_ACTIVE) | |
375 | return; | |
376 | ||
377 | DPRINTF("cancelling migration\n"); | |
378 | ||
379 | s->state = MIG_STATE_CANCELLED; | |
380 | notifier_list_notify(&migration_state_notifiers, s); | |
381 | qemu_savevm_state_cancel(s->file); | |
382 | ||
383 | migrate_fd_cleanup(s); | |
384 | } | |
385 | ||
386 | int migrate_fd_wait_for_unfreeze(MigrationState *s) | |
387 | { | |
388 | int ret; | |
389 | ||
390 | DPRINTF("wait for unfreeze\n"); | |
391 | if (s->state != MIG_STATE_ACTIVE) | |
392 | return -EINVAL; | |
393 | ||
394 | do { | |
395 | fd_set wfds; | |
396 | ||
397 | FD_ZERO(&wfds); | |
398 | FD_SET(s->fd, &wfds); | |
399 | ||
400 | ret = select(s->fd + 1, NULL, &wfds, NULL, NULL); | |
401 | } while (ret == -1 && (s->get_error(s)) == EINTR); | |
402 | ||
403 | if (ret == -1) { | |
404 | return -s->get_error(s); | |
405 | } | |
406 | return 0; | |
407 | } | |
408 | ||
409 | int migrate_fd_close(MigrationState *s) | |
410 | { | |
411 | int rc = 0; | |
412 | if (s->fd != -1) { | |
413 | qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); | |
414 | rc = s->close(s); | |
415 | s->fd = -1; | |
416 | } | |
417 | return rc; | |
418 | } | |
419 | ||
420 | void add_migration_state_change_notifier(Notifier *notify) | |
421 | { | |
422 | notifier_list_add(&migration_state_notifiers, notify); | |
423 | } | |
424 | ||
425 | void remove_migration_state_change_notifier(Notifier *notify) | |
426 | { | |
427 | notifier_remove(notify); | |
428 | } | |
429 | ||
430 | bool migration_is_active(MigrationState *s) | |
431 | { | |
432 | return s->state == MIG_STATE_ACTIVE; | |
433 | } | |
434 | ||
435 | bool migration_has_finished(MigrationState *s) | |
436 | { | |
437 | return s->state == MIG_STATE_COMPLETED; | |
438 | } | |
439 | ||
440 | bool migration_has_failed(MigrationState *s) | |
441 | { | |
442 | return (s->state == MIG_STATE_CANCELLED || | |
443 | s->state == MIG_STATE_ERROR); | |
444 | } | |
445 | ||
446 | void migrate_fd_connect(MigrationState *s) | |
447 | { | |
448 | int ret; | |
449 | ||
450 | s->state = MIG_STATE_ACTIVE; | |
451 | s->file = qemu_fopen_ops_buffered(s); | |
452 | ||
453 | DPRINTF("beginning savevm\n"); | |
454 | ret = qemu_savevm_state_begin(s->file, &s->params); | |
455 | if (ret < 0) { | |
456 | DPRINTF("failed, %d\n", ret); | |
457 | migrate_fd_error(s); | |
458 | return; | |
459 | } | |
460 | migrate_fd_put_ready(s); | |
461 | } | |
462 | ||
463 | static MigrationState *migrate_init(const MigrationParams *params) | |
464 | { | |
465 | MigrationState *s = migrate_get_current(); | |
466 | int64_t bandwidth_limit = s->bandwidth_limit; | |
467 | bool enabled_capabilities[MIGRATION_CAPABILITY_MAX]; | |
468 | int64_t xbzrle_cache_size = s->xbzrle_cache_size; | |
469 | ||
470 | memcpy(enabled_capabilities, s->enabled_capabilities, | |
471 | sizeof(enabled_capabilities)); | |
472 | ||
473 | memset(s, 0, sizeof(*s)); | |
474 | s->bandwidth_limit = bandwidth_limit; | |
475 | s->params = *params; | |
476 | memcpy(s->enabled_capabilities, enabled_capabilities, | |
477 | sizeof(enabled_capabilities)); | |
478 | s->xbzrle_cache_size = xbzrle_cache_size; | |
479 | ||
480 | s->bandwidth_limit = bandwidth_limit; | |
481 | s->state = MIG_STATE_SETUP; | |
482 | s->total_time = qemu_get_clock_ms(rt_clock); | |
483 | ||
484 | return s; | |
485 | } | |
486 | ||
487 | static GSList *migration_blockers; | |
488 | ||
489 | void migrate_add_blocker(Error *reason) | |
490 | { | |
491 | migration_blockers = g_slist_prepend(migration_blockers, reason); | |
492 | } | |
493 | ||
494 | void migrate_del_blocker(Error *reason) | |
495 | { | |
496 | migration_blockers = g_slist_remove(migration_blockers, reason); | |
497 | } | |
498 | ||
499 | void qmp_migrate(const char *uri, bool has_blk, bool blk, | |
500 | bool has_inc, bool inc, bool has_detach, bool detach, | |
501 | Error **errp) | |
502 | { | |
503 | Error *local_err = NULL; | |
504 | MigrationState *s = migrate_get_current(); | |
505 | MigrationParams params; | |
506 | const char *p; | |
507 | ||
508 | params.blk = blk; | |
509 | params.shared = inc; | |
510 | ||
511 | if (s->state == MIG_STATE_ACTIVE) { | |
512 | error_set(errp, QERR_MIGRATION_ACTIVE); | |
513 | return; | |
514 | } | |
515 | ||
516 | if (qemu_savevm_state_blocked(errp)) { | |
517 | return; | |
518 | } | |
519 | ||
520 | if (migration_blockers) { | |
521 | *errp = error_copy(migration_blockers->data); | |
522 | return; | |
523 | } | |
524 | ||
525 | s = migrate_init(¶ms); | |
526 | ||
527 | if (strstart(uri, "tcp:", &p)) { | |
528 | tcp_start_outgoing_migration(s, p, &local_err); | |
529 | #if !defined(WIN32) | |
530 | } else if (strstart(uri, "exec:", &p)) { | |
531 | exec_start_outgoing_migration(s, p, &local_err); | |
532 | } else if (strstart(uri, "unix:", &p)) { | |
533 | unix_start_outgoing_migration(s, p, &local_err); | |
534 | } else if (strstart(uri, "fd:", &p)) { | |
535 | fd_start_outgoing_migration(s, p, &local_err); | |
536 | #endif | |
537 | } else { | |
538 | error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol"); | |
539 | return; | |
540 | } | |
541 | ||
542 | if (local_err) { | |
543 | migrate_fd_error(s); | |
544 | error_propagate(errp, local_err); | |
545 | return; | |
546 | } | |
547 | ||
548 | notifier_list_notify(&migration_state_notifiers, s); | |
549 | } | |
550 | ||
551 | void qmp_migrate_cancel(Error **errp) | |
552 | { | |
553 | migrate_fd_cancel(migrate_get_current()); | |
554 | } | |
555 | ||
556 | void qmp_migrate_set_cache_size(int64_t value, Error **errp) | |
557 | { | |
558 | MigrationState *s = migrate_get_current(); | |
559 | ||
560 | /* Check for truncation */ | |
561 | if (value != (size_t)value) { | |
562 | error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", | |
563 | "exceeding address space"); | |
564 | return; | |
565 | } | |
566 | ||
567 | s->xbzrle_cache_size = xbzrle_cache_resize(value); | |
568 | } | |
569 | ||
570 | int64_t qmp_query_migrate_cache_size(Error **errp) | |
571 | { | |
572 | return migrate_xbzrle_cache_size(); | |
573 | } | |
574 | ||
575 | void qmp_migrate_set_speed(int64_t value, Error **errp) | |
576 | { | |
577 | MigrationState *s; | |
578 | ||
579 | if (value < 0) { | |
580 | value = 0; | |
581 | } | |
582 | ||
583 | s = migrate_get_current(); | |
584 | s->bandwidth_limit = value; | |
585 | qemu_file_set_rate_limit(s->file, s->bandwidth_limit); | |
586 | } | |
587 | ||
588 | void qmp_migrate_set_downtime(double value, Error **errp) | |
589 | { | |
590 | value *= 1e9; | |
591 | value = MAX(0, MIN(UINT64_MAX, value)); | |
592 | max_downtime = (uint64_t)value; | |
593 | } | |
594 | ||
595 | int migrate_use_xbzrle(void) | |
596 | { | |
597 | MigrationState *s; | |
598 | ||
599 | s = migrate_get_current(); | |
600 | ||
601 | return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; | |
602 | } | |
603 | ||
604 | int64_t migrate_xbzrle_cache_size(void) | |
605 | { | |
606 | MigrationState *s; | |
607 | ||
608 | s = migrate_get_current(); | |
609 | ||
610 | return s->xbzrle_cache_size; | |
611 | } |