PPC: rename msync to msync_4xx
[qemu.git] / 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-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 &current_migration;
61 }
62
63 int qemu_start_incoming_migration(const char *uri)
64 {
65 const char *p;
66 int ret;
67
68 if (strstart(uri, "tcp:", &p))
69 ret = tcp_start_incoming_migration(p);
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 /* Make sure all file formats flush their mutable metadata */
95 bdrv_invalidate_cache_all();
96
97 if (autostart) {
98 vm_start();
99 } else {
100 runstate_set(RUN_STATE_PRELAUNCH);
101 }
102 }
103
104 /* amount of nanoseconds we are willing to wait for migration to be down.
105 * the choice of nanoseconds is because it is the maximum resolution that
106 * get_clock() can achieve. It is an internal measure. All user-visible
107 * units must be in seconds */
108 static uint64_t max_downtime = 30000000;
109
110 uint64_t migrate_max_downtime(void)
111 {
112 return max_downtime;
113 }
114
115 MigrationInfo *qmp_query_migrate(Error **errp)
116 {
117 MigrationInfo *info = g_malloc0(sizeof(*info));
118 MigrationState *s = migrate_get_current();
119
120 switch (s->state) {
121 case MIG_STATE_SETUP:
122 /* no migration has happened ever */
123 break;
124 case MIG_STATE_ACTIVE:
125 info->has_status = true;
126 info->status = g_strdup("active");
127
128 info->has_ram = true;
129 info->ram = g_malloc0(sizeof(*info->ram));
130 info->ram->transferred = ram_bytes_transferred();
131 info->ram->remaining = ram_bytes_remaining();
132 info->ram->total = ram_bytes_total();
133
134 if (blk_mig_active()) {
135 info->has_disk = true;
136 info->disk = g_malloc0(sizeof(*info->disk));
137 info->disk->transferred = blk_mig_bytes_transferred();
138 info->disk->remaining = blk_mig_bytes_remaining();
139 info->disk->total = blk_mig_bytes_total();
140 }
141 break;
142 case MIG_STATE_COMPLETED:
143 info->has_status = true;
144 info->status = g_strdup("completed");
145 break;
146 case MIG_STATE_ERROR:
147 info->has_status = true;
148 info->status = g_strdup("failed");
149 break;
150 case MIG_STATE_CANCELLED:
151 info->has_status = true;
152 info->status = g_strdup("cancelled");
153 break;
154 }
155
156 return info;
157 }
158
159 /* shared migration helpers */
160
161 static void migrate_fd_monitor_suspend(MigrationState *s, Monitor *mon)
162 {
163 if (monitor_suspend(mon) == 0) {
164 DPRINTF("suspending monitor\n");
165 } else {
166 monitor_printf(mon, "terminal does not allow synchronous "
167 "migration, continuing detached\n");
168 }
169 }
170
171 static int migrate_fd_cleanup(MigrationState *s)
172 {
173 int ret = 0;
174
175 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
176
177 if (s->file) {
178 DPRINTF("closing file\n");
179 ret = qemu_fclose(s->file);
180 s->file = NULL;
181 } else {
182 if (s->mon) {
183 monitor_resume(s->mon);
184 }
185 }
186
187 if (s->fd != -1) {
188 close(s->fd);
189 s->fd = -1;
190 }
191
192 return ret;
193 }
194
195 void migrate_fd_error(MigrationState *s)
196 {
197 DPRINTF("setting error state\n");
198 s->state = MIG_STATE_ERROR;
199 notifier_list_notify(&migration_state_notifiers, s);
200 migrate_fd_cleanup(s);
201 }
202
203 static void migrate_fd_completed(MigrationState *s)
204 {
205 DPRINTF("setting completed state\n");
206 if (migrate_fd_cleanup(s) < 0) {
207 s->state = MIG_STATE_ERROR;
208 } else {
209 s->state = MIG_STATE_COMPLETED;
210 runstate_set(RUN_STATE_POSTMIGRATE);
211 }
212 notifier_list_notify(&migration_state_notifiers, s);
213 }
214
215 static void migrate_fd_put_notify(void *opaque)
216 {
217 MigrationState *s = opaque;
218
219 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
220 qemu_file_put_notify(s->file);
221 if (s->file && qemu_file_get_error(s->file)) {
222 migrate_fd_error(s);
223 }
224 }
225
226 static ssize_t migrate_fd_put_buffer(void *opaque, const void *data,
227 size_t size)
228 {
229 MigrationState *s = opaque;
230 ssize_t ret;
231
232 if (s->state != MIG_STATE_ACTIVE) {
233 return -EIO;
234 }
235
236 do {
237 ret = s->write(s, data, size);
238 } while (ret == -1 && ((s->get_error(s)) == EINTR));
239
240 if (ret == -1)
241 ret = -(s->get_error(s));
242
243 if (ret == -EAGAIN) {
244 qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
245 }
246
247 return ret;
248 }
249
250 static void migrate_fd_put_ready(void *opaque)
251 {
252 MigrationState *s = opaque;
253 int ret;
254
255 if (s->state != MIG_STATE_ACTIVE) {
256 DPRINTF("put_ready returning because of non-active state\n");
257 return;
258 }
259
260 DPRINTF("iterate\n");
261 ret = qemu_savevm_state_iterate(s->mon, s->file);
262 if (ret < 0) {
263 migrate_fd_error(s);
264 } else if (ret == 1) {
265 int old_vm_running = runstate_is_running();
266
267 DPRINTF("done iterating\n");
268 vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
269
270 if (qemu_savevm_state_complete(s->mon, s->file) < 0) {
271 migrate_fd_error(s);
272 } else {
273 migrate_fd_completed(s);
274 }
275 if (s->state != MIG_STATE_COMPLETED) {
276 if (old_vm_running) {
277 vm_start();
278 }
279 }
280 }
281 }
282
283 static void migrate_fd_cancel(MigrationState *s)
284 {
285 if (s->state != MIG_STATE_ACTIVE)
286 return;
287
288 DPRINTF("cancelling migration\n");
289
290 s->state = MIG_STATE_CANCELLED;
291 notifier_list_notify(&migration_state_notifiers, s);
292 qemu_savevm_state_cancel(s->mon, s->file);
293
294 migrate_fd_cleanup(s);
295 }
296
297 static void migrate_fd_wait_for_unfreeze(void *opaque)
298 {
299 MigrationState *s = opaque;
300 int ret;
301
302 DPRINTF("wait for unfreeze\n");
303 if (s->state != MIG_STATE_ACTIVE)
304 return;
305
306 do {
307 fd_set wfds;
308
309 FD_ZERO(&wfds);
310 FD_SET(s->fd, &wfds);
311
312 ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
313 } while (ret == -1 && (s->get_error(s)) == EINTR);
314
315 if (ret == -1) {
316 qemu_file_set_error(s->file, -s->get_error(s));
317 }
318 }
319
320 static int migrate_fd_close(void *opaque)
321 {
322 MigrationState *s = opaque;
323
324 if (s->mon) {
325 monitor_resume(s->mon);
326 }
327 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
328 return s->close(s);
329 }
330
331 void add_migration_state_change_notifier(Notifier *notify)
332 {
333 notifier_list_add(&migration_state_notifiers, notify);
334 }
335
336 void remove_migration_state_change_notifier(Notifier *notify)
337 {
338 notifier_list_remove(&migration_state_notifiers, notify);
339 }
340
341 bool migration_is_active(MigrationState *s)
342 {
343 return s->state == MIG_STATE_ACTIVE;
344 }
345
346 bool migration_has_finished(MigrationState *s)
347 {
348 return s->state == MIG_STATE_COMPLETED;
349 }
350
351 bool migration_has_failed(MigrationState *s)
352 {
353 return (s->state == MIG_STATE_CANCELLED ||
354 s->state == MIG_STATE_ERROR);
355 }
356
357 void migrate_fd_connect(MigrationState *s)
358 {
359 int ret;
360
361 s->state = MIG_STATE_ACTIVE;
362 s->file = qemu_fopen_ops_buffered(s,
363 s->bandwidth_limit,
364 migrate_fd_put_buffer,
365 migrate_fd_put_ready,
366 migrate_fd_wait_for_unfreeze,
367 migrate_fd_close);
368
369 DPRINTF("beginning savevm\n");
370 ret = qemu_savevm_state_begin(s->mon, s->file, s->blk, s->shared);
371 if (ret < 0) {
372 DPRINTF("failed, %d\n", ret);
373 migrate_fd_error(s);
374 return;
375 }
376 migrate_fd_put_ready(s);
377 }
378
379 static MigrationState *migrate_init(Monitor *mon, int detach, int blk, int inc)
380 {
381 MigrationState *s = migrate_get_current();
382 int64_t bandwidth_limit = s->bandwidth_limit;
383
384 memset(s, 0, sizeof(*s));
385 s->bandwidth_limit = bandwidth_limit;
386 s->blk = blk;
387 s->shared = inc;
388
389 /* s->mon is used for two things:
390 - pass fd in fd migration
391 - suspend/resume monitor for not detached migration
392 */
393 s->mon = mon;
394 s->bandwidth_limit = bandwidth_limit;
395 s->state = MIG_STATE_SETUP;
396
397 if (!detach) {
398 migrate_fd_monitor_suspend(s, mon);
399 }
400
401 return s;
402 }
403
404 static GSList *migration_blockers;
405
406 void migrate_add_blocker(Error *reason)
407 {
408 migration_blockers = g_slist_prepend(migration_blockers, reason);
409 }
410
411 void migrate_del_blocker(Error *reason)
412 {
413 migration_blockers = g_slist_remove(migration_blockers, reason);
414 }
415
416 int do_migrate(Monitor *mon, const QDict *qdict, QObject **ret_data)
417 {
418 MigrationState *s = migrate_get_current();
419 const char *p;
420 int detach = qdict_get_try_bool(qdict, "detach", 0);
421 int blk = qdict_get_try_bool(qdict, "blk", 0);
422 int inc = qdict_get_try_bool(qdict, "inc", 0);
423 const char *uri = qdict_get_str(qdict, "uri");
424 int ret;
425
426 if (s->state == MIG_STATE_ACTIVE) {
427 monitor_printf(mon, "migration already in progress\n");
428 return -1;
429 }
430
431 if (qemu_savevm_state_blocked(mon)) {
432 return -1;
433 }
434
435 if (migration_blockers) {
436 Error *err = migration_blockers->data;
437 qerror_report_err(err);
438 return -1;
439 }
440
441 s = migrate_init(mon, detach, blk, inc);
442
443 if (strstart(uri, "tcp:", &p)) {
444 ret = tcp_start_outgoing_migration(s, p);
445 #if !defined(WIN32)
446 } else if (strstart(uri, "exec:", &p)) {
447 ret = exec_start_outgoing_migration(s, p);
448 } else if (strstart(uri, "unix:", &p)) {
449 ret = unix_start_outgoing_migration(s, p);
450 } else if (strstart(uri, "fd:", &p)) {
451 ret = fd_start_outgoing_migration(s, p);
452 #endif
453 } else {
454 monitor_printf(mon, "unknown migration protocol: %s\n", uri);
455 ret = -EINVAL;
456 }
457
458 if (ret < 0) {
459 monitor_printf(mon, "migration failed: %s\n", strerror(-ret));
460 return ret;
461 }
462
463 if (detach) {
464 s->mon = NULL;
465 }
466
467 notifier_list_notify(&migration_state_notifiers, s);
468 return 0;
469 }
470
471 void qmp_migrate_cancel(Error **errp)
472 {
473 migrate_fd_cancel(migrate_get_current());
474 }
475
476 void qmp_migrate_set_speed(int64_t value, Error **errp)
477 {
478 MigrationState *s;
479
480 if (value < 0) {
481 value = 0;
482 }
483
484 s = migrate_get_current();
485 s->bandwidth_limit = value;
486 qemu_file_set_rate_limit(s->file, s->bandwidth_limit);
487 }
488
489 void qmp_migrate_set_downtime(double value, Error **errp)
490 {
491 value *= 1e9;
492 value = MAX(0, MIN(UINT64_MAX, value));
493 max_downtime = (uint64_t)value;
494 }