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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 | static NotifierList migration_state_notifiers = | |
47 | NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); | |
48 | ||
49 | /* When we add fault tolerance, we could have several | |
50 | migrations at once. For now we don't need to add | |
51 | dynamic creation of migration */ | |
52 | ||
53 | static MigrationState *migrate_get_current(void) | |
54 | { | |
55 | static MigrationState current_migration = { | |
56 | .state = MIG_STATE_SETUP, | |
57 | .bandwidth_limit = MAX_THROTTLE, | |
58 | }; | |
59 | ||
60 | return ¤t_migration; | |
61 | } | |
62 | ||
63 | int qemu_start_incoming_migration(const char *uri, Error **errp) | |
64 | { | |
65 | const char *p; | |
66 | int ret; | |
67 | ||
68 | if (strstart(uri, "tcp:", &p)) | |
69 | ret = tcp_start_incoming_migration(p, errp); | |
70 | #if !defined(WIN32) | |
71 | else if (strstart(uri, "exec:", &p)) | |
72 | ret = exec_start_incoming_migration(p); | |
73 | else if (strstart(uri, "unix:", &p)) | |
74 | ret = unix_start_incoming_migration(p); | |
75 | else if (strstart(uri, "fd:", &p)) | |
76 | ret = fd_start_incoming_migration(p); | |
77 | #endif | |
78 | else { | |
79 | fprintf(stderr, "unknown migration protocol: %s\n", uri); | |
80 | ret = -EPROTONOSUPPORT; | |
81 | } | |
82 | return ret; | |
83 | } | |
84 | ||
85 | void process_incoming_migration(QEMUFile *f) | |
86 | { | |
87 | if (qemu_loadvm_state(f) < 0) { | |
88 | fprintf(stderr, "load of migration failed\n"); | |
89 | exit(0); | |
90 | } | |
91 | qemu_announce_self(); | |
92 | DPRINTF("successfully loaded vm state\n"); | |
93 | ||
94 | bdrv_clear_incoming_migration_all(); | |
95 | /* Make sure all file formats flush their mutable metadata */ | |
96 | bdrv_invalidate_cache_all(); | |
97 | ||
98 | if (autostart) { | |
99 | vm_start(); | |
100 | } else { | |
101 | runstate_set(RUN_STATE_PRELAUNCH); | |
102 | } | |
103 | } | |
104 | ||
105 | /* amount of nanoseconds we are willing to wait for migration to be down. | |
106 | * the choice of nanoseconds is because it is the maximum resolution that | |
107 | * get_clock() can achieve. It is an internal measure. All user-visible | |
108 | * units must be in seconds */ | |
109 | static uint64_t max_downtime = 30000000; | |
110 | ||
111 | uint64_t migrate_max_downtime(void) | |
112 | { | |
113 | return max_downtime; | |
114 | } | |
115 | ||
116 | MigrationInfo *qmp_query_migrate(Error **errp) | |
117 | { | |
118 | MigrationInfo *info = g_malloc0(sizeof(*info)); | |
119 | MigrationState *s = migrate_get_current(); | |
120 | ||
121 | switch (s->state) { | |
122 | case MIG_STATE_SETUP: | |
123 | /* no migration has happened ever */ | |
124 | break; | |
125 | case MIG_STATE_ACTIVE: | |
126 | info->has_status = true; | |
127 | info->status = g_strdup("active"); | |
128 | ||
129 | info->has_ram = true; | |
130 | info->ram = g_malloc0(sizeof(*info->ram)); | |
131 | info->ram->transferred = ram_bytes_transferred(); | |
132 | info->ram->remaining = ram_bytes_remaining(); | |
133 | info->ram->total = ram_bytes_total(); | |
134 | ||
135 | if (blk_mig_active()) { | |
136 | info->has_disk = true; | |
137 | info->disk = g_malloc0(sizeof(*info->disk)); | |
138 | info->disk->transferred = blk_mig_bytes_transferred(); | |
139 | info->disk->remaining = blk_mig_bytes_remaining(); | |
140 | info->disk->total = blk_mig_bytes_total(); | |
141 | } | |
142 | break; | |
143 | case MIG_STATE_COMPLETED: | |
144 | info->has_status = true; | |
145 | info->status = g_strdup("completed"); | |
146 | break; | |
147 | case MIG_STATE_ERROR: | |
148 | info->has_status = true; | |
149 | info->status = g_strdup("failed"); | |
150 | break; | |
151 | case MIG_STATE_CANCELLED: | |
152 | info->has_status = true; | |
153 | info->status = g_strdup("cancelled"); | |
154 | break; | |
155 | } | |
156 | ||
157 | return info; | |
158 | } | |
159 | ||
160 | /* shared migration helpers */ | |
161 | ||
162 | static int migrate_fd_cleanup(MigrationState *s) | |
163 | { | |
164 | int ret = 0; | |
165 | ||
166 | qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); | |
167 | ||
168 | if (s->file) { | |
169 | DPRINTF("closing file\n"); | |
170 | ret = qemu_fclose(s->file); | |
171 | s->file = NULL; | |
172 | } | |
173 | ||
174 | if (s->fd != -1) { | |
175 | close(s->fd); | |
176 | s->fd = -1; | |
177 | } | |
178 | ||
179 | return ret; | |
180 | } | |
181 | ||
182 | void migrate_fd_error(MigrationState *s) | |
183 | { | |
184 | DPRINTF("setting error state\n"); | |
185 | s->state = MIG_STATE_ERROR; | |
186 | notifier_list_notify(&migration_state_notifiers, s); | |
187 | migrate_fd_cleanup(s); | |
188 | } | |
189 | ||
190 | static void migrate_fd_completed(MigrationState *s) | |
191 | { | |
192 | DPRINTF("setting completed state\n"); | |
193 | if (migrate_fd_cleanup(s) < 0) { | |
194 | s->state = MIG_STATE_ERROR; | |
195 | } else { | |
196 | s->state = MIG_STATE_COMPLETED; | |
197 | runstate_set(RUN_STATE_POSTMIGRATE); | |
198 | } | |
199 | notifier_list_notify(&migration_state_notifiers, s); | |
200 | } | |
201 | ||
202 | static void migrate_fd_put_notify(void *opaque) | |
203 | { | |
204 | MigrationState *s = opaque; | |
205 | ||
206 | qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); | |
207 | qemu_file_put_notify(s->file); | |
208 | if (s->file && qemu_file_get_error(s->file)) { | |
209 | migrate_fd_error(s); | |
210 | } | |
211 | } | |
212 | ||
213 | static ssize_t migrate_fd_put_buffer(void *opaque, const void *data, | |
214 | size_t size) | |
215 | { | |
216 | MigrationState *s = opaque; | |
217 | ssize_t ret; | |
218 | ||
219 | if (s->state != MIG_STATE_ACTIVE) { | |
220 | return -EIO; | |
221 | } | |
222 | ||
223 | do { | |
224 | ret = s->write(s, data, size); | |
225 | } while (ret == -1 && ((s->get_error(s)) == EINTR)); | |
226 | ||
227 | if (ret == -1) | |
228 | ret = -(s->get_error(s)); | |
229 | ||
230 | if (ret == -EAGAIN) { | |
231 | qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s); | |
232 | } | |
233 | ||
234 | return ret; | |
235 | } | |
236 | ||
237 | static void migrate_fd_put_ready(void *opaque) | |
238 | { | |
239 | MigrationState *s = opaque; | |
240 | int ret; | |
241 | ||
242 | if (s->state != MIG_STATE_ACTIVE) { | |
243 | DPRINTF("put_ready returning because of non-active state\n"); | |
244 | return; | |
245 | } | |
246 | ||
247 | DPRINTF("iterate\n"); | |
248 | ret = qemu_savevm_state_iterate(s->file); | |
249 | if (ret < 0) { | |
250 | migrate_fd_error(s); | |
251 | } else if (ret == 1) { | |
252 | int old_vm_running = runstate_is_running(); | |
253 | ||
254 | DPRINTF("done iterating\n"); | |
255 | qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); | |
256 | vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); | |
257 | ||
258 | if (qemu_savevm_state_complete(s->file) < 0) { | |
259 | migrate_fd_error(s); | |
260 | } else { | |
261 | migrate_fd_completed(s); | |
262 | } | |
263 | if (s->state != MIG_STATE_COMPLETED) { | |
264 | if (old_vm_running) { | |
265 | vm_start(); | |
266 | } | |
267 | } | |
268 | } | |
269 | } | |
270 | ||
271 | static void migrate_fd_cancel(MigrationState *s) | |
272 | { | |
273 | if (s->state != MIG_STATE_ACTIVE) | |
274 | return; | |
275 | ||
276 | DPRINTF("cancelling migration\n"); | |
277 | ||
278 | s->state = MIG_STATE_CANCELLED; | |
279 | notifier_list_notify(&migration_state_notifiers, s); | |
280 | qemu_savevm_state_cancel(s->file); | |
281 | ||
282 | migrate_fd_cleanup(s); | |
283 | } | |
284 | ||
285 | static void migrate_fd_wait_for_unfreeze(void *opaque) | |
286 | { | |
287 | MigrationState *s = opaque; | |
288 | int ret; | |
289 | ||
290 | DPRINTF("wait for unfreeze\n"); | |
291 | if (s->state != MIG_STATE_ACTIVE) | |
292 | return; | |
293 | ||
294 | do { | |
295 | fd_set wfds; | |
296 | ||
297 | FD_ZERO(&wfds); | |
298 | FD_SET(s->fd, &wfds); | |
299 | ||
300 | ret = select(s->fd + 1, NULL, &wfds, NULL, NULL); | |
301 | } while (ret == -1 && (s->get_error(s)) == EINTR); | |
302 | ||
303 | if (ret == -1) { | |
304 | qemu_file_set_error(s->file, -s->get_error(s)); | |
305 | } | |
306 | } | |
307 | ||
308 | static int migrate_fd_close(void *opaque) | |
309 | { | |
310 | MigrationState *s = opaque; | |
311 | ||
312 | qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); | |
313 | return s->close(s); | |
314 | } | |
315 | ||
316 | void add_migration_state_change_notifier(Notifier *notify) | |
317 | { | |
318 | notifier_list_add(&migration_state_notifiers, notify); | |
319 | } | |
320 | ||
321 | void remove_migration_state_change_notifier(Notifier *notify) | |
322 | { | |
323 | notifier_remove(notify); | |
324 | } | |
325 | ||
326 | bool migration_is_active(MigrationState *s) | |
327 | { | |
328 | return s->state == MIG_STATE_ACTIVE; | |
329 | } | |
330 | ||
331 | bool migration_has_finished(MigrationState *s) | |
332 | { | |
333 | return s->state == MIG_STATE_COMPLETED; | |
334 | } | |
335 | ||
336 | bool migration_has_failed(MigrationState *s) | |
337 | { | |
338 | return (s->state == MIG_STATE_CANCELLED || | |
339 | s->state == MIG_STATE_ERROR); | |
340 | } | |
341 | ||
342 | void migrate_fd_connect(MigrationState *s) | |
343 | { | |
344 | int ret; | |
345 | ||
346 | s->state = MIG_STATE_ACTIVE; | |
347 | s->file = qemu_fopen_ops_buffered(s, | |
348 | s->bandwidth_limit, | |
349 | migrate_fd_put_buffer, | |
350 | migrate_fd_put_ready, | |
351 | migrate_fd_wait_for_unfreeze, | |
352 | migrate_fd_close); | |
353 | ||
354 | DPRINTF("beginning savevm\n"); | |
355 | ret = qemu_savevm_state_begin(s->file, s->blk, s->shared); | |
356 | if (ret < 0) { | |
357 | DPRINTF("failed, %d\n", ret); | |
358 | migrate_fd_error(s); | |
359 | return; | |
360 | } | |
361 | migrate_fd_put_ready(s); | |
362 | } | |
363 | ||
364 | static MigrationState *migrate_init(int blk, int inc) | |
365 | { | |
366 | MigrationState *s = migrate_get_current(); | |
367 | int64_t bandwidth_limit = s->bandwidth_limit; | |
368 | ||
369 | memset(s, 0, sizeof(*s)); | |
370 | s->bandwidth_limit = bandwidth_limit; | |
371 | s->blk = blk; | |
372 | s->shared = inc; | |
373 | ||
374 | s->bandwidth_limit = bandwidth_limit; | |
375 | s->state = MIG_STATE_SETUP; | |
376 | ||
377 | return s; | |
378 | } | |
379 | ||
380 | static GSList *migration_blockers; | |
381 | ||
382 | void migrate_add_blocker(Error *reason) | |
383 | { | |
384 | migration_blockers = g_slist_prepend(migration_blockers, reason); | |
385 | } | |
386 | ||
387 | void migrate_del_blocker(Error *reason) | |
388 | { | |
389 | migration_blockers = g_slist_remove(migration_blockers, reason); | |
390 | } | |
391 | ||
392 | void qmp_migrate(const char *uri, bool has_blk, bool blk, | |
393 | bool has_inc, bool inc, bool has_detach, bool detach, | |
394 | Error **errp) | |
395 | { | |
396 | MigrationState *s = migrate_get_current(); | |
397 | const char *p; | |
398 | int ret; | |
399 | ||
400 | if (s->state == MIG_STATE_ACTIVE) { | |
401 | error_set(errp, QERR_MIGRATION_ACTIVE); | |
402 | return; | |
403 | } | |
404 | ||
405 | if (qemu_savevm_state_blocked(errp)) { | |
406 | return; | |
407 | } | |
408 | ||
409 | if (migration_blockers) { | |
410 | *errp = error_copy(migration_blockers->data); | |
411 | return; | |
412 | } | |
413 | ||
414 | s = migrate_init(blk, inc); | |
415 | ||
416 | if (strstart(uri, "tcp:", &p)) { | |
417 | ret = tcp_start_outgoing_migration(s, p, errp); | |
418 | #if !defined(WIN32) | |
419 | } else if (strstart(uri, "exec:", &p)) { | |
420 | ret = exec_start_outgoing_migration(s, p); | |
421 | } else if (strstart(uri, "unix:", &p)) { | |
422 | ret = unix_start_outgoing_migration(s, p); | |
423 | } else if (strstart(uri, "fd:", &p)) { | |
424 | ret = fd_start_outgoing_migration(s, p); | |
425 | #endif | |
426 | } else { | |
427 | error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol"); | |
428 | return; | |
429 | } | |
430 | ||
431 | if (ret < 0) { | |
432 | if (!error_is_set(errp)) { | |
433 | DPRINTF("migration failed: %s\n", strerror(-ret)); | |
434 | /* FIXME: we should return meaningful errors */ | |
435 | error_set(errp, QERR_UNDEFINED_ERROR); | |
436 | } | |
437 | return; | |
438 | } | |
439 | ||
440 | notifier_list_notify(&migration_state_notifiers, s); | |
441 | } | |
442 | ||
443 | void qmp_migrate_cancel(Error **errp) | |
444 | { | |
445 | migrate_fd_cancel(migrate_get_current()); | |
446 | } | |
447 | ||
448 | void qmp_migrate_set_speed(int64_t value, Error **errp) | |
449 | { | |
450 | MigrationState *s; | |
451 | ||
452 | if (value < 0) { | |
453 | value = 0; | |
454 | } | |
455 | ||
456 | s = migrate_get_current(); | |
457 | s->bandwidth_limit = value; | |
458 | qemu_file_set_rate_limit(s->file, s->bandwidth_limit); | |
459 | } | |
460 | ||
461 | void qmp_migrate_set_downtime(double value, Error **errp) | |
462 | { | |
463 | value *= 1e9; | |
464 | value = MAX(0, MIN(UINT64_MAX, value)); | |
465 | max_downtime = (uint64_t)value; | |
466 | } |