python/qemu/console_socket.py: Clarify type of drain_thread
[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/blocker.h"
21 #include "exec.h"
22 #include "fd.h"
23 #include "socket.h"
24 #include "sysemu/runstate.h"
25 #include "sysemu/sysemu.h"
26 #include "sysemu/cpu-throttle.h"
27 #include "rdma.h"
28 #include "ram.h"
29 #include "migration/global_state.h"
30 #include "migration/misc.h"
31 #include "migration.h"
32 #include "savevm.h"
33 #include "qemu-file-channel.h"
34 #include "qemu-file.h"
35 #include "migration/vmstate.h"
36 #include "block/block.h"
37 #include "qapi/error.h"
38 #include "qapi/clone-visitor.h"
39 #include "qapi/qapi-visit-migration.h"
40 #include "qapi/qapi-visit-sockets.h"
41 #include "qapi/qapi-commands-migration.h"
42 #include "qapi/qapi-events-migration.h"
43 #include "qapi/qmp/qerror.h"
44 #include "qapi/qmp/qnull.h"
45 #include "qemu/rcu.h"
46 #include "block.h"
47 #include "postcopy-ram.h"
48 #include "qemu/thread.h"
49 #include "trace.h"
50 #include "exec/target_page.h"
51 #include "io/channel-buffer.h"
52 #include "migration/colo.h"
53 #include "hw/boards.h"
54 #include "hw/qdev-properties.h"
55 #include "monitor/monitor.h"
56 #include "net/announce.h"
57 #include "qemu/queue.h"
58 #include "multifd.h"
59
60 #define MAX_THROTTLE (128 << 20) /* Migration transfer speed throttling */
61
62 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
63 * data. */
64 #define BUFFER_DELAY 100
65 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
66
67 /* Time in milliseconds we are allowed to stop the source,
68 * for sending the last part */
69 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
70
71 /* Maximum migrate downtime set to 2000 seconds */
72 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000
73 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000)
74
75 /* Default compression thread count */
76 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
77 /* Default decompression thread count, usually decompression is at
78 * least 4 times as fast as compression.*/
79 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
80 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
81 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
82 /* Define default autoconverge cpu throttle migration parameters */
83 #define DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD 50
84 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
85 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
86 #define DEFAULT_MIGRATE_MAX_CPU_THROTTLE 99
87
88 /* Migration XBZRLE default cache size */
89 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024)
90
91 /* The delay time (in ms) between two COLO checkpoints */
92 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100)
93 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
94 #define DEFAULT_MIGRATE_MULTIFD_COMPRESSION MULTIFD_COMPRESSION_NONE
95 /* 0: means nocompress, 1: best speed, ... 9: best compress ratio */
96 #define DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL 1
97 /* 0: means nocompress, 1: best speed, ... 20: best compress ratio */
98 #define DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL 1
99
100 /* Background transfer rate for postcopy, 0 means unlimited, note
101 * that page requests can still exceed this limit.
102 */
103 #define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0
104
105 /*
106 * Parameters for self_announce_delay giving a stream of RARP/ARP
107 * packets after migration.
108 */
109 #define DEFAULT_MIGRATE_ANNOUNCE_INITIAL 50
110 #define DEFAULT_MIGRATE_ANNOUNCE_MAX 550
111 #define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS 5
112 #define DEFAULT_MIGRATE_ANNOUNCE_STEP 100
113
114 static NotifierList migration_state_notifiers =
115 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
116
117 static bool deferred_incoming;
118
119 /* Messages sent on the return path from destination to source */
120 enum mig_rp_message_type {
121 MIG_RP_MSG_INVALID = 0, /* Must be 0 */
122 MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */
123 MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */
124
125 MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
126 MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */
127 MIG_RP_MSG_RECV_BITMAP, /* send recved_bitmap back to source */
128 MIG_RP_MSG_RESUME_ACK, /* tell source that we are ready to resume */
129
130 MIG_RP_MSG_MAX
131 };
132
133 /* When we add fault tolerance, we could have several
134 migrations at once. For now we don't need to add
135 dynamic creation of migration */
136
137 static MigrationState *current_migration;
138 static MigrationIncomingState *current_incoming;
139
140 static bool migration_object_check(MigrationState *ms, Error **errp);
141 static int migration_maybe_pause(MigrationState *s,
142 int *current_active_state,
143 int new_state);
144 static void migrate_fd_cancel(MigrationState *s);
145
146 void migration_object_init(void)
147 {
148 MachineState *ms = MACHINE(qdev_get_machine());
149 Error *err = NULL;
150
151 /* This can only be called once. */
152 assert(!current_migration);
153 current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
154
155 /*
156 * Init the migrate incoming object as well no matter whether
157 * we'll use it or not.
158 */
159 assert(!current_incoming);
160 current_incoming = g_new0(MigrationIncomingState, 1);
161 current_incoming->state = MIGRATION_STATUS_NONE;
162 current_incoming->postcopy_remote_fds =
163 g_array_new(FALSE, TRUE, sizeof(struct PostCopyFD));
164 qemu_mutex_init(&current_incoming->rp_mutex);
165 qemu_event_init(&current_incoming->main_thread_load_event, false);
166 qemu_sem_init(&current_incoming->postcopy_pause_sem_dst, 0);
167 qemu_sem_init(&current_incoming->postcopy_pause_sem_fault, 0);
168
169 if (!migration_object_check(current_migration, &err)) {
170 error_report_err(err);
171 exit(1);
172 }
173
174 /*
175 * We cannot really do this in migration_instance_init() since at
176 * that time global properties are not yet applied, then this
177 * value will be definitely replaced by something else.
178 */
179 if (ms->enforce_config_section) {
180 current_migration->send_configuration = true;
181 }
182 }
183
184 void migration_shutdown(void)
185 {
186 /*
187 * Cancel the current migration - that will (eventually)
188 * stop the migration using this structure
189 */
190 migrate_fd_cancel(current_migration);
191 object_unref(OBJECT(current_migration));
192
193 /*
194 * Cancel outgoing migration of dirty bitmaps. It should
195 * at least unref used block nodes.
196 */
197 dirty_bitmap_mig_cancel_outgoing();
198
199 /*
200 * Cancel incoming migration of dirty bitmaps. Dirty bitmaps
201 * are non-critical data, and their loss never considered as
202 * something serious.
203 */
204 dirty_bitmap_mig_cancel_incoming();
205 }
206
207 /* For outgoing */
208 MigrationState *migrate_get_current(void)
209 {
210 /* This can only be called after the object created. */
211 assert(current_migration);
212 return current_migration;
213 }
214
215 MigrationIncomingState *migration_incoming_get_current(void)
216 {
217 assert(current_incoming);
218 return current_incoming;
219 }
220
221 void migration_incoming_state_destroy(void)
222 {
223 struct MigrationIncomingState *mis = migration_incoming_get_current();
224
225 if (mis->to_src_file) {
226 /* Tell source that we are done */
227 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
228 qemu_fclose(mis->to_src_file);
229 mis->to_src_file = NULL;
230 }
231
232 if (mis->from_src_file) {
233 qemu_fclose(mis->from_src_file);
234 mis->from_src_file = NULL;
235 }
236 if (mis->postcopy_remote_fds) {
237 g_array_free(mis->postcopy_remote_fds, TRUE);
238 mis->postcopy_remote_fds = NULL;
239 }
240
241 qemu_event_reset(&mis->main_thread_load_event);
242
243 if (mis->socket_address_list) {
244 qapi_free_SocketAddressList(mis->socket_address_list);
245 mis->socket_address_list = NULL;
246 }
247 }
248
249 static void migrate_generate_event(int new_state)
250 {
251 if (migrate_use_events()) {
252 qapi_event_send_migration(new_state);
253 }
254 }
255
256 static bool migrate_late_block_activate(void)
257 {
258 MigrationState *s;
259
260 s = migrate_get_current();
261
262 return s->enabled_capabilities[
263 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE];
264 }
265
266 /*
267 * Called on -incoming with a defer: uri.
268 * The migration can be started later after any parameters have been
269 * changed.
270 */
271 static void deferred_incoming_migration(Error **errp)
272 {
273 if (deferred_incoming) {
274 error_setg(errp, "Incoming migration already deferred");
275 }
276 deferred_incoming = true;
277 }
278
279 /*
280 * Send a message on the return channel back to the source
281 * of the migration.
282 */
283 static int migrate_send_rp_message(MigrationIncomingState *mis,
284 enum mig_rp_message_type message_type,
285 uint16_t len, void *data)
286 {
287 int ret = 0;
288
289 trace_migrate_send_rp_message((int)message_type, len);
290 qemu_mutex_lock(&mis->rp_mutex);
291
292 /*
293 * It's possible that the file handle got lost due to network
294 * failures.
295 */
296 if (!mis->to_src_file) {
297 ret = -EIO;
298 goto error;
299 }
300
301 qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
302 qemu_put_be16(mis->to_src_file, len);
303 qemu_put_buffer(mis->to_src_file, data, len);
304 qemu_fflush(mis->to_src_file);
305
306 /* It's possible that qemu file got error during sending */
307 ret = qemu_file_get_error(mis->to_src_file);
308
309 error:
310 qemu_mutex_unlock(&mis->rp_mutex);
311 return ret;
312 }
313
314 /* Request one page from the source VM at the given start address.
315 * rb: the RAMBlock to request the page in
316 * Start: Address offset within the RB
317 * Len: Length in bytes required - must be a multiple of pagesize
318 */
319 int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb,
320 ram_addr_t start)
321 {
322 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
323 size_t msglen = 12; /* start + len */
324 size_t len = qemu_ram_pagesize(rb);
325 enum mig_rp_message_type msg_type;
326 const char *rbname;
327 int rbname_len;
328
329 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
330 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
331
332 /*
333 * We maintain the last ramblock that we requested for page. Note that we
334 * don't need locking because this function will only be called within the
335 * postcopy ram fault thread.
336 */
337 if (rb != mis->last_rb) {
338 mis->last_rb = rb;
339
340 rbname = qemu_ram_get_idstr(rb);
341 rbname_len = strlen(rbname);
342
343 assert(rbname_len < 256);
344
345 bufc[msglen++] = rbname_len;
346 memcpy(bufc + msglen, rbname, rbname_len);
347 msglen += rbname_len;
348 msg_type = MIG_RP_MSG_REQ_PAGES_ID;
349 } else {
350 msg_type = MIG_RP_MSG_REQ_PAGES;
351 }
352
353 return migrate_send_rp_message(mis, msg_type, msglen, bufc);
354 }
355
356 static bool migration_colo_enabled;
357 bool migration_incoming_colo_enabled(void)
358 {
359 return migration_colo_enabled;
360 }
361
362 void migration_incoming_disable_colo(void)
363 {
364 ram_block_discard_disable(false);
365 migration_colo_enabled = false;
366 }
367
368 int migration_incoming_enable_colo(void)
369 {
370 if (ram_block_discard_disable(true)) {
371 error_report("COLO: cannot disable RAM discard");
372 return -EBUSY;
373 }
374 migration_colo_enabled = true;
375 return 0;
376 }
377
378 void migrate_add_address(SocketAddress *address)
379 {
380 MigrationIncomingState *mis = migration_incoming_get_current();
381 SocketAddressList *addrs;
382
383 addrs = g_new0(SocketAddressList, 1);
384 addrs->next = mis->socket_address_list;
385 mis->socket_address_list = addrs;
386 addrs->value = QAPI_CLONE(SocketAddress, address);
387 }
388
389 void qemu_start_incoming_migration(const char *uri, Error **errp)
390 {
391 const char *p = NULL;
392
393 qapi_event_send_migration(MIGRATION_STATUS_SETUP);
394 if (!strcmp(uri, "defer")) {
395 deferred_incoming_migration(errp);
396 } else if (strstart(uri, "tcp:", &p) ||
397 strstart(uri, "unix:", NULL) ||
398 strstart(uri, "vsock:", NULL)) {
399 socket_start_incoming_migration(p ? p : uri, errp);
400 #ifdef CONFIG_RDMA
401 } else if (strstart(uri, "rdma:", &p)) {
402 rdma_start_incoming_migration(p, errp);
403 #endif
404 } else if (strstart(uri, "exec:", &p)) {
405 exec_start_incoming_migration(p, errp);
406 } else if (strstart(uri, "fd:", &p)) {
407 fd_start_incoming_migration(p, errp);
408 } else {
409 error_setg(errp, "unknown migration protocol: %s", uri);
410 }
411 }
412
413 static void process_incoming_migration_bh(void *opaque)
414 {
415 Error *local_err = NULL;
416 MigrationIncomingState *mis = opaque;
417
418 /* If capability late_block_activate is set:
419 * Only fire up the block code now if we're going to restart the
420 * VM, else 'cont' will do it.
421 * This causes file locking to happen; so we don't want it to happen
422 * unless we really are starting the VM.
423 */
424 if (!migrate_late_block_activate() ||
425 (autostart && (!global_state_received() ||
426 global_state_get_runstate() == RUN_STATE_RUNNING))) {
427 /* Make sure all file formats flush their mutable metadata.
428 * If we get an error here, just don't restart the VM yet. */
429 bdrv_invalidate_cache_all(&local_err);
430 if (local_err) {
431 error_report_err(local_err);
432 local_err = NULL;
433 autostart = false;
434 }
435 }
436
437 /*
438 * This must happen after all error conditions are dealt with and
439 * we're sure the VM is going to be running on this host.
440 */
441 qemu_announce_self(&mis->announce_timer, migrate_announce_params());
442
443 if (multifd_load_cleanup(&local_err) != 0) {
444 error_report_err(local_err);
445 autostart = false;
446 }
447 /* If global state section was not received or we are in running
448 state, we need to obey autostart. Any other state is set with
449 runstate_set. */
450
451 dirty_bitmap_mig_before_vm_start();
452
453 if (!global_state_received() ||
454 global_state_get_runstate() == RUN_STATE_RUNNING) {
455 if (autostart) {
456 vm_start();
457 } else {
458 runstate_set(RUN_STATE_PAUSED);
459 }
460 } else if (migration_incoming_colo_enabled()) {
461 migration_incoming_disable_colo();
462 vm_start();
463 } else {
464 runstate_set(global_state_get_runstate());
465 }
466 /*
467 * This must happen after any state changes since as soon as an external
468 * observer sees this event they might start to prod at the VM assuming
469 * it's ready to use.
470 */
471 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
472 MIGRATION_STATUS_COMPLETED);
473 qemu_bh_delete(mis->bh);
474 migration_incoming_state_destroy();
475 }
476
477 static void process_incoming_migration_co(void *opaque)
478 {
479 MigrationIncomingState *mis = migration_incoming_get_current();
480 PostcopyState ps;
481 int ret;
482 Error *local_err = NULL;
483
484 assert(mis->from_src_file);
485 mis->migration_incoming_co = qemu_coroutine_self();
486 mis->largest_page_size = qemu_ram_pagesize_largest();
487 postcopy_state_set(POSTCOPY_INCOMING_NONE);
488 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
489 MIGRATION_STATUS_ACTIVE);
490 ret = qemu_loadvm_state(mis->from_src_file);
491
492 ps = postcopy_state_get();
493 trace_process_incoming_migration_co_end(ret, ps);
494 if (ps != POSTCOPY_INCOMING_NONE) {
495 if (ps == POSTCOPY_INCOMING_ADVISE) {
496 /*
497 * Where a migration had postcopy enabled (and thus went to advise)
498 * but managed to complete within the precopy period, we can use
499 * the normal exit.
500 */
501 postcopy_ram_incoming_cleanup(mis);
502 } else if (ret >= 0) {
503 /*
504 * Postcopy was started, cleanup should happen at the end of the
505 * postcopy thread.
506 */
507 trace_process_incoming_migration_co_postcopy_end_main();
508 return;
509 }
510 /* Else if something went wrong then just fall out of the normal exit */
511 }
512
513 /* we get COLO info, and know if we are in COLO mode */
514 if (!ret && migration_incoming_colo_enabled()) {
515 /* Make sure all file formats flush their mutable metadata */
516 bdrv_invalidate_cache_all(&local_err);
517 if (local_err) {
518 error_report_err(local_err);
519 goto fail;
520 }
521
522 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming",
523 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
524 mis->have_colo_incoming_thread = true;
525 qemu_coroutine_yield();
526
527 /* Wait checkpoint incoming thread exit before free resource */
528 qemu_thread_join(&mis->colo_incoming_thread);
529 /* We hold the global iothread lock, so it is safe here */
530 colo_release_ram_cache();
531 }
532
533 if (ret < 0) {
534 error_report("load of migration failed: %s", strerror(-ret));
535 goto fail;
536 }
537 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
538 qemu_bh_schedule(mis->bh);
539 mis->migration_incoming_co = NULL;
540 return;
541 fail:
542 local_err = NULL;
543 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
544 MIGRATION_STATUS_FAILED);
545 qemu_fclose(mis->from_src_file);
546 if (multifd_load_cleanup(&local_err) != 0) {
547 error_report_err(local_err);
548 }
549 exit(EXIT_FAILURE);
550 }
551
552 /**
553 * @migration_incoming_setup: Setup incoming migration
554 *
555 * Returns 0 for no error or 1 for error
556 *
557 * @f: file for main migration channel
558 * @errp: where to put errors
559 */
560 static int migration_incoming_setup(QEMUFile *f, Error **errp)
561 {
562 MigrationIncomingState *mis = migration_incoming_get_current();
563 Error *local_err = NULL;
564
565 if (multifd_load_setup(&local_err) != 0) {
566 /* We haven't been able to create multifd threads
567 nothing better to do */
568 error_report_err(local_err);
569 exit(EXIT_FAILURE);
570 }
571
572 if (!mis->from_src_file) {
573 mis->from_src_file = f;
574 }
575 qemu_file_set_blocking(f, false);
576 return 0;
577 }
578
579 void migration_incoming_process(void)
580 {
581 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
582 qemu_coroutine_enter(co);
583 }
584
585 /* Returns true if recovered from a paused migration, otherwise false */
586 static bool postcopy_try_recover(QEMUFile *f)
587 {
588 MigrationIncomingState *mis = migration_incoming_get_current();
589
590 if (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
591 /* Resumed from a paused postcopy migration */
592
593 mis->from_src_file = f;
594 /* Postcopy has standalone thread to do vm load */
595 qemu_file_set_blocking(f, true);
596
597 /* Re-configure the return path */
598 mis->to_src_file = qemu_file_get_return_path(f);
599
600 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_PAUSED,
601 MIGRATION_STATUS_POSTCOPY_RECOVER);
602
603 /*
604 * Here, we only wake up the main loading thread (while the
605 * fault thread will still be waiting), so that we can receive
606 * commands from source now, and answer it if needed. The
607 * fault thread will be woken up afterwards until we are sure
608 * that source is ready to reply to page requests.
609 */
610 qemu_sem_post(&mis->postcopy_pause_sem_dst);
611 return true;
612 }
613
614 return false;
615 }
616
617 void migration_fd_process_incoming(QEMUFile *f, Error **errp)
618 {
619 Error *local_err = NULL;
620
621 if (postcopy_try_recover(f)) {
622 return;
623 }
624
625 if (migration_incoming_setup(f, &local_err)) {
626 error_propagate(errp, local_err);
627 return;
628 }
629 migration_incoming_process();
630 }
631
632 void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp)
633 {
634 MigrationIncomingState *mis = migration_incoming_get_current();
635 Error *local_err = NULL;
636 bool start_migration;
637
638 if (!mis->from_src_file) {
639 /* The first connection (multifd may have multiple) */
640 QEMUFile *f = qemu_fopen_channel_input(ioc);
641
642 /* If it's a recovery, we're done */
643 if (postcopy_try_recover(f)) {
644 return;
645 }
646
647 if (migration_incoming_setup(f, &local_err)) {
648 error_propagate(errp, local_err);
649 return;
650 }
651
652 /*
653 * Common migration only needs one channel, so we can start
654 * right now. Multifd needs more than one channel, we wait.
655 */
656 start_migration = !migrate_use_multifd();
657 } else {
658 /* Multiple connections */
659 assert(migrate_use_multifd());
660 start_migration = multifd_recv_new_channel(ioc, &local_err);
661 if (local_err) {
662 error_propagate(errp, local_err);
663 return;
664 }
665 }
666
667 if (start_migration) {
668 migration_incoming_process();
669 }
670 }
671
672 /**
673 * @migration_has_all_channels: We have received all channels that we need
674 *
675 * Returns true when we have got connections to all the channels that
676 * we need for migration.
677 */
678 bool migration_has_all_channels(void)
679 {
680 MigrationIncomingState *mis = migration_incoming_get_current();
681 bool all_channels;
682
683 all_channels = multifd_recv_all_channels_created();
684
685 return all_channels && mis->from_src_file != NULL;
686 }
687
688 /*
689 * Send a 'SHUT' message on the return channel with the given value
690 * to indicate that we've finished with the RP. Non-0 value indicates
691 * error.
692 */
693 void migrate_send_rp_shut(MigrationIncomingState *mis,
694 uint32_t value)
695 {
696 uint32_t buf;
697
698 buf = cpu_to_be32(value);
699 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
700 }
701
702 /*
703 * Send a 'PONG' message on the return channel with the given value
704 * (normally in response to a 'PING')
705 */
706 void migrate_send_rp_pong(MigrationIncomingState *mis,
707 uint32_t value)
708 {
709 uint32_t buf;
710
711 buf = cpu_to_be32(value);
712 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
713 }
714
715 void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
716 char *block_name)
717 {
718 char buf[512];
719 int len;
720 int64_t res;
721
722 /*
723 * First, we send the header part. It contains only the len of
724 * idstr, and the idstr itself.
725 */
726 len = strlen(block_name);
727 buf[0] = len;
728 memcpy(buf + 1, block_name, len);
729
730 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
731 error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
732 __func__);
733 return;
734 }
735
736 migrate_send_rp_message(mis, MIG_RP_MSG_RECV_BITMAP, len + 1, buf);
737
738 /*
739 * Next, we dump the received bitmap to the stream.
740 *
741 * TODO: currently we are safe since we are the only one that is
742 * using the to_src_file handle (fault thread is still paused),
743 * and it's ok even not taking the mutex. However the best way is
744 * to take the lock before sending the message header, and release
745 * the lock after sending the bitmap.
746 */
747 qemu_mutex_lock(&mis->rp_mutex);
748 res = ramblock_recv_bitmap_send(mis->to_src_file, block_name);
749 qemu_mutex_unlock(&mis->rp_mutex);
750
751 trace_migrate_send_rp_recv_bitmap(block_name, res);
752 }
753
754 void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value)
755 {
756 uint32_t buf;
757
758 buf = cpu_to_be32(value);
759 migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf);
760 }
761
762 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
763 {
764 MigrationCapabilityStatusList *head = NULL;
765 MigrationCapabilityStatusList *caps;
766 MigrationState *s = migrate_get_current();
767 int i;
768
769 caps = NULL; /* silence compiler warning */
770 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
771 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
772 if (i == MIGRATION_CAPABILITY_BLOCK) {
773 continue;
774 }
775 #endif
776 if (head == NULL) {
777 head = g_malloc0(sizeof(*caps));
778 caps = head;
779 } else {
780 caps->next = g_malloc0(sizeof(*caps));
781 caps = caps->next;
782 }
783 caps->value =
784 g_malloc(sizeof(*caps->value));
785 caps->value->capability = i;
786 caps->value->state = s->enabled_capabilities[i];
787 }
788
789 return head;
790 }
791
792 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
793 {
794 MigrationParameters *params;
795 MigrationState *s = migrate_get_current();
796
797 /* TODO use QAPI_CLONE() instead of duplicating it inline */
798 params = g_malloc0(sizeof(*params));
799 params->has_compress_level = true;
800 params->compress_level = s->parameters.compress_level;
801 params->has_compress_threads = true;
802 params->compress_threads = s->parameters.compress_threads;
803 params->has_compress_wait_thread = true;
804 params->compress_wait_thread = s->parameters.compress_wait_thread;
805 params->has_decompress_threads = true;
806 params->decompress_threads = s->parameters.decompress_threads;
807 params->has_throttle_trigger_threshold = true;
808 params->throttle_trigger_threshold = s->parameters.throttle_trigger_threshold;
809 params->has_cpu_throttle_initial = true;
810 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial;
811 params->has_cpu_throttle_increment = true;
812 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment;
813 params->has_cpu_throttle_tailslow = true;
814 params->cpu_throttle_tailslow = s->parameters.cpu_throttle_tailslow;
815 params->has_tls_creds = true;
816 params->tls_creds = g_strdup(s->parameters.tls_creds);
817 params->has_tls_hostname = true;
818 params->tls_hostname = g_strdup(s->parameters.tls_hostname);
819 params->has_tls_authz = true;
820 params->tls_authz = g_strdup(s->parameters.tls_authz ?
821 s->parameters.tls_authz : "");
822 params->has_max_bandwidth = true;
823 params->max_bandwidth = s->parameters.max_bandwidth;
824 params->has_downtime_limit = true;
825 params->downtime_limit = s->parameters.downtime_limit;
826 params->has_x_checkpoint_delay = true;
827 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay;
828 params->has_block_incremental = true;
829 params->block_incremental = s->parameters.block_incremental;
830 params->has_multifd_channels = true;
831 params->multifd_channels = s->parameters.multifd_channels;
832 params->has_multifd_compression = true;
833 params->multifd_compression = s->parameters.multifd_compression;
834 params->has_multifd_zlib_level = true;
835 params->multifd_zlib_level = s->parameters.multifd_zlib_level;
836 params->has_multifd_zstd_level = true;
837 params->multifd_zstd_level = s->parameters.multifd_zstd_level;
838 params->has_xbzrle_cache_size = true;
839 params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
840 params->has_max_postcopy_bandwidth = true;
841 params->max_postcopy_bandwidth = s->parameters.max_postcopy_bandwidth;
842 params->has_max_cpu_throttle = true;
843 params->max_cpu_throttle = s->parameters.max_cpu_throttle;
844 params->has_announce_initial = true;
845 params->announce_initial = s->parameters.announce_initial;
846 params->has_announce_max = true;
847 params->announce_max = s->parameters.announce_max;
848 params->has_announce_rounds = true;
849 params->announce_rounds = s->parameters.announce_rounds;
850 params->has_announce_step = true;
851 params->announce_step = s->parameters.announce_step;
852
853 if (s->parameters.has_block_bitmap_mapping) {
854 params->has_block_bitmap_mapping = true;
855 params->block_bitmap_mapping =
856 QAPI_CLONE(BitmapMigrationNodeAliasList,
857 s->parameters.block_bitmap_mapping);
858 }
859
860 return params;
861 }
862
863 AnnounceParameters *migrate_announce_params(void)
864 {
865 static AnnounceParameters ap;
866
867 MigrationState *s = migrate_get_current();
868
869 ap.initial = s->parameters.announce_initial;
870 ap.max = s->parameters.announce_max;
871 ap.rounds = s->parameters.announce_rounds;
872 ap.step = s->parameters.announce_step;
873
874 return &ap;
875 }
876
877 /*
878 * Return true if we're already in the middle of a migration
879 * (i.e. any of the active or setup states)
880 */
881 bool migration_is_setup_or_active(int state)
882 {
883 switch (state) {
884 case MIGRATION_STATUS_ACTIVE:
885 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
886 case MIGRATION_STATUS_POSTCOPY_PAUSED:
887 case MIGRATION_STATUS_POSTCOPY_RECOVER:
888 case MIGRATION_STATUS_SETUP:
889 case MIGRATION_STATUS_PRE_SWITCHOVER:
890 case MIGRATION_STATUS_DEVICE:
891 case MIGRATION_STATUS_WAIT_UNPLUG:
892 case MIGRATION_STATUS_COLO:
893 return true;
894
895 default:
896 return false;
897
898 }
899 }
900
901 bool migration_is_running(int state)
902 {
903 switch (state) {
904 case MIGRATION_STATUS_ACTIVE:
905 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
906 case MIGRATION_STATUS_POSTCOPY_PAUSED:
907 case MIGRATION_STATUS_POSTCOPY_RECOVER:
908 case MIGRATION_STATUS_SETUP:
909 case MIGRATION_STATUS_PRE_SWITCHOVER:
910 case MIGRATION_STATUS_DEVICE:
911 case MIGRATION_STATUS_WAIT_UNPLUG:
912 case MIGRATION_STATUS_CANCELLING:
913 return true;
914
915 default:
916 return false;
917
918 }
919 }
920
921 static void populate_time_info(MigrationInfo *info, MigrationState *s)
922 {
923 info->has_status = true;
924 info->has_setup_time = true;
925 info->setup_time = s->setup_time;
926 if (s->state == MIGRATION_STATUS_COMPLETED) {
927 info->has_total_time = true;
928 info->total_time = s->total_time;
929 info->has_downtime = true;
930 info->downtime = s->downtime;
931 } else {
932 info->has_total_time = true;
933 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) -
934 s->start_time;
935 info->has_expected_downtime = true;
936 info->expected_downtime = s->expected_downtime;
937 }
938 }
939
940 static void populate_ram_info(MigrationInfo *info, MigrationState *s)
941 {
942 info->has_ram = true;
943 info->ram = g_malloc0(sizeof(*info->ram));
944 info->ram->transferred = ram_counters.transferred;
945 info->ram->total = ram_bytes_total();
946 info->ram->duplicate = ram_counters.duplicate;
947 /* legacy value. It is not used anymore */
948 info->ram->skipped = 0;
949 info->ram->normal = ram_counters.normal;
950 info->ram->normal_bytes = ram_counters.normal *
951 qemu_target_page_size();
952 info->ram->mbps = s->mbps;
953 info->ram->dirty_sync_count = ram_counters.dirty_sync_count;
954 info->ram->postcopy_requests = ram_counters.postcopy_requests;
955 info->ram->page_size = qemu_target_page_size();
956 info->ram->multifd_bytes = ram_counters.multifd_bytes;
957 info->ram->pages_per_second = s->pages_per_second;
958
959 if (migrate_use_xbzrle()) {
960 info->has_xbzrle_cache = true;
961 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
962 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
963 info->xbzrle_cache->bytes = xbzrle_counters.bytes;
964 info->xbzrle_cache->pages = xbzrle_counters.pages;
965 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss;
966 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate;
967 info->xbzrle_cache->encoding_rate = xbzrle_counters.encoding_rate;
968 info->xbzrle_cache->overflow = xbzrle_counters.overflow;
969 }
970
971 if (migrate_use_compression()) {
972 info->has_compression = true;
973 info->compression = g_malloc0(sizeof(*info->compression));
974 info->compression->pages = compression_counters.pages;
975 info->compression->busy = compression_counters.busy;
976 info->compression->busy_rate = compression_counters.busy_rate;
977 info->compression->compressed_size =
978 compression_counters.compressed_size;
979 info->compression->compression_rate =
980 compression_counters.compression_rate;
981 }
982
983 if (cpu_throttle_active()) {
984 info->has_cpu_throttle_percentage = true;
985 info->cpu_throttle_percentage = cpu_throttle_get_percentage();
986 }
987
988 if (s->state != MIGRATION_STATUS_COMPLETED) {
989 info->ram->remaining = ram_bytes_remaining();
990 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate;
991 }
992 }
993
994 static void populate_disk_info(MigrationInfo *info)
995 {
996 if (blk_mig_active()) {
997 info->has_disk = true;
998 info->disk = g_malloc0(sizeof(*info->disk));
999 info->disk->transferred = blk_mig_bytes_transferred();
1000 info->disk->remaining = blk_mig_bytes_remaining();
1001 info->disk->total = blk_mig_bytes_total();
1002 }
1003 }
1004
1005 static void fill_source_migration_info(MigrationInfo *info)
1006 {
1007 MigrationState *s = migrate_get_current();
1008
1009 switch (s->state) {
1010 case MIGRATION_STATUS_NONE:
1011 /* no migration has happened ever */
1012 /* do not overwrite destination migration status */
1013 return;
1014 case MIGRATION_STATUS_SETUP:
1015 info->has_status = true;
1016 info->has_total_time = false;
1017 break;
1018 case MIGRATION_STATUS_ACTIVE:
1019 case MIGRATION_STATUS_CANCELLING:
1020 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1021 case MIGRATION_STATUS_PRE_SWITCHOVER:
1022 case MIGRATION_STATUS_DEVICE:
1023 case MIGRATION_STATUS_POSTCOPY_PAUSED:
1024 case MIGRATION_STATUS_POSTCOPY_RECOVER:
1025 /* TODO add some postcopy stats */
1026 populate_time_info(info, s);
1027 populate_ram_info(info, s);
1028 populate_disk_info(info);
1029 break;
1030 case MIGRATION_STATUS_COLO:
1031 info->has_status = true;
1032 /* TODO: display COLO specific information (checkpoint info etc.) */
1033 break;
1034 case MIGRATION_STATUS_COMPLETED:
1035 populate_time_info(info, s);
1036 populate_ram_info(info, s);
1037 break;
1038 case MIGRATION_STATUS_FAILED:
1039 info->has_status = true;
1040 if (s->error) {
1041 info->has_error_desc = true;
1042 info->error_desc = g_strdup(error_get_pretty(s->error));
1043 }
1044 break;
1045 case MIGRATION_STATUS_CANCELLED:
1046 info->has_status = true;
1047 break;
1048 case MIGRATION_STATUS_WAIT_UNPLUG:
1049 info->has_status = true;
1050 break;
1051 }
1052 info->status = s->state;
1053 }
1054
1055 /**
1056 * @migration_caps_check - check capability validity
1057 *
1058 * @cap_list: old capability list, array of bool
1059 * @params: new capabilities to be applied soon
1060 * @errp: set *errp if the check failed, with reason
1061 *
1062 * Returns true if check passed, otherwise false.
1063 */
1064 static bool migrate_caps_check(bool *cap_list,
1065 MigrationCapabilityStatusList *params,
1066 Error **errp)
1067 {
1068 MigrationCapabilityStatusList *cap;
1069 bool old_postcopy_cap;
1070 MigrationIncomingState *mis = migration_incoming_get_current();
1071
1072 old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM];
1073
1074 for (cap = params; cap; cap = cap->next) {
1075 cap_list[cap->value->capability] = cap->value->state;
1076 }
1077
1078 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
1079 if (cap_list[MIGRATION_CAPABILITY_BLOCK]) {
1080 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) "
1081 "block migration");
1082 error_append_hint(errp, "Use drive_mirror+NBD instead.\n");
1083 return false;
1084 }
1085 #endif
1086
1087 #ifndef CONFIG_REPLICATION
1088 if (cap_list[MIGRATION_CAPABILITY_X_COLO]) {
1089 error_setg(errp, "QEMU compiled without replication module"
1090 " can't enable COLO");
1091 error_append_hint(errp, "Please enable replication before COLO.\n");
1092 return false;
1093 }
1094 #endif
1095
1096 if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) {
1097 /* This check is reasonably expensive, so only when it's being
1098 * set the first time, also it's only the destination that needs
1099 * special support.
1100 */
1101 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) &&
1102 !postcopy_ram_supported_by_host(mis)) {
1103 /* postcopy_ram_supported_by_host will have emitted a more
1104 * detailed message
1105 */
1106 error_setg(errp, "Postcopy is not supported");
1107 return false;
1108 }
1109
1110 if (cap_list[MIGRATION_CAPABILITY_X_IGNORE_SHARED]) {
1111 error_setg(errp, "Postcopy is not compatible with ignore-shared");
1112 return false;
1113 }
1114 }
1115
1116 return true;
1117 }
1118
1119 static void fill_destination_migration_info(MigrationInfo *info)
1120 {
1121 MigrationIncomingState *mis = migration_incoming_get_current();
1122
1123 if (mis->socket_address_list) {
1124 info->has_socket_address = true;
1125 info->socket_address =
1126 QAPI_CLONE(SocketAddressList, mis->socket_address_list);
1127 }
1128
1129 switch (mis->state) {
1130 case MIGRATION_STATUS_NONE:
1131 return;
1132 case MIGRATION_STATUS_SETUP:
1133 case MIGRATION_STATUS_CANCELLING:
1134 case MIGRATION_STATUS_CANCELLED:
1135 case MIGRATION_STATUS_ACTIVE:
1136 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1137 case MIGRATION_STATUS_POSTCOPY_PAUSED:
1138 case MIGRATION_STATUS_POSTCOPY_RECOVER:
1139 case MIGRATION_STATUS_FAILED:
1140 case MIGRATION_STATUS_COLO:
1141 info->has_status = true;
1142 break;
1143 case MIGRATION_STATUS_COMPLETED:
1144 info->has_status = true;
1145 fill_destination_postcopy_migration_info(info);
1146 break;
1147 }
1148 info->status = mis->state;
1149 }
1150
1151 MigrationInfo *qmp_query_migrate(Error **errp)
1152 {
1153 MigrationInfo *info = g_malloc0(sizeof(*info));
1154
1155 fill_destination_migration_info(info);
1156 fill_source_migration_info(info);
1157
1158 return info;
1159 }
1160
1161 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
1162 Error **errp)
1163 {
1164 MigrationState *s = migrate_get_current();
1165 MigrationCapabilityStatusList *cap;
1166 bool cap_list[MIGRATION_CAPABILITY__MAX];
1167
1168 if (migration_is_running(s->state)) {
1169 error_setg(errp, QERR_MIGRATION_ACTIVE);
1170 return;
1171 }
1172
1173 memcpy(cap_list, s->enabled_capabilities, sizeof(cap_list));
1174 if (!migrate_caps_check(cap_list, params, errp)) {
1175 return;
1176 }
1177
1178 for (cap = params; cap; cap = cap->next) {
1179 s->enabled_capabilities[cap->value->capability] = cap->value->state;
1180 }
1181 }
1182
1183 /*
1184 * Check whether the parameters are valid. Error will be put into errp
1185 * (if provided). Return true if valid, otherwise false.
1186 */
1187 static bool migrate_params_check(MigrationParameters *params, Error **errp)
1188 {
1189 if (params->has_compress_level &&
1190 (params->compress_level > 9)) {
1191 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
1192 "is invalid, it should be in the range of 0 to 9");
1193 return false;
1194 }
1195
1196 if (params->has_compress_threads && (params->compress_threads < 1)) {
1197 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1198 "compress_threads",
1199 "is invalid, it should be in the range of 1 to 255");
1200 return false;
1201 }
1202
1203 if (params->has_decompress_threads && (params->decompress_threads < 1)) {
1204 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1205 "decompress_threads",
1206 "is invalid, it should be in the range of 1 to 255");
1207 return false;
1208 }
1209
1210 if (params->has_throttle_trigger_threshold &&
1211 (params->throttle_trigger_threshold < 1 ||
1212 params->throttle_trigger_threshold > 100)) {
1213 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1214 "throttle_trigger_threshold",
1215 "an integer in the range of 1 to 100");
1216 return false;
1217 }
1218
1219 if (params->has_cpu_throttle_initial &&
1220 (params->cpu_throttle_initial < 1 ||
1221 params->cpu_throttle_initial > 99)) {
1222 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1223 "cpu_throttle_initial",
1224 "an integer in the range of 1 to 99");
1225 return false;
1226 }
1227
1228 if (params->has_cpu_throttle_increment &&
1229 (params->cpu_throttle_increment < 1 ||
1230 params->cpu_throttle_increment > 99)) {
1231 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1232 "cpu_throttle_increment",
1233 "an integer in the range of 1 to 99");
1234 return false;
1235 }
1236
1237 if (params->has_max_bandwidth && (params->max_bandwidth > SIZE_MAX)) {
1238 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1239 "max_bandwidth",
1240 "an integer in the range of 0 to "stringify(SIZE_MAX)
1241 " bytes/second");
1242 return false;
1243 }
1244
1245 if (params->has_downtime_limit &&
1246 (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) {
1247 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1248 "downtime_limit",
1249 "an integer in the range of 0 to "
1250 stringify(MAX_MIGRATE_DOWNTIME)" ms");
1251 return false;
1252 }
1253
1254 /* x_checkpoint_delay is now always positive */
1255
1256 if (params->has_multifd_channels && (params->multifd_channels < 1)) {
1257 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1258 "multifd_channels",
1259 "is invalid, it should be in the range of 1 to 255");
1260 return false;
1261 }
1262
1263 if (params->has_multifd_zlib_level &&
1264 (params->multifd_zlib_level > 9)) {
1265 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zlib_level",
1266 "is invalid, it should be in the range of 0 to 9");
1267 return false;
1268 }
1269
1270 if (params->has_multifd_zstd_level &&
1271 (params->multifd_zstd_level > 20)) {
1272 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zstd_level",
1273 "is invalid, it should be in the range of 0 to 20");
1274 return false;
1275 }
1276
1277 if (params->has_xbzrle_cache_size &&
1278 (params->xbzrle_cache_size < qemu_target_page_size() ||
1279 !is_power_of_2(params->xbzrle_cache_size))) {
1280 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1281 "xbzrle_cache_size",
1282 "is invalid, it should be bigger than target page size"
1283 " and a power of 2");
1284 return false;
1285 }
1286
1287 if (params->has_max_cpu_throttle &&
1288 (params->max_cpu_throttle < params->cpu_throttle_initial ||
1289 params->max_cpu_throttle > 99)) {
1290 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1291 "max_cpu_throttle",
1292 "an integer in the range of cpu_throttle_initial to 99");
1293 return false;
1294 }
1295
1296 if (params->has_announce_initial &&
1297 params->announce_initial > 100000) {
1298 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1299 "announce_initial",
1300 "is invalid, it must be less than 100000 ms");
1301 return false;
1302 }
1303 if (params->has_announce_max &&
1304 params->announce_max > 100000) {
1305 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1306 "announce_max",
1307 "is invalid, it must be less than 100000 ms");
1308 return false;
1309 }
1310 if (params->has_announce_rounds &&
1311 params->announce_rounds > 1000) {
1312 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1313 "announce_rounds",
1314 "is invalid, it must be in the range of 0 to 1000");
1315 return false;
1316 }
1317 if (params->has_announce_step &&
1318 (params->announce_step < 1 ||
1319 params->announce_step > 10000)) {
1320 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1321 "announce_step",
1322 "is invalid, it must be in the range of 1 to 10000 ms");
1323 return false;
1324 }
1325
1326 if (params->has_block_bitmap_mapping &&
1327 !check_dirty_bitmap_mig_alias_map(params->block_bitmap_mapping, errp)) {
1328 error_prepend(errp, "Invalid mapping given for block-bitmap-mapping: ");
1329 return false;
1330 }
1331
1332 return true;
1333 }
1334
1335 static void migrate_params_test_apply(MigrateSetParameters *params,
1336 MigrationParameters *dest)
1337 {
1338 *dest = migrate_get_current()->parameters;
1339
1340 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1341
1342 if (params->has_compress_level) {
1343 dest->compress_level = params->compress_level;
1344 }
1345
1346 if (params->has_compress_threads) {
1347 dest->compress_threads = params->compress_threads;
1348 }
1349
1350 if (params->has_compress_wait_thread) {
1351 dest->compress_wait_thread = params->compress_wait_thread;
1352 }
1353
1354 if (params->has_decompress_threads) {
1355 dest->decompress_threads = params->decompress_threads;
1356 }
1357
1358 if (params->has_throttle_trigger_threshold) {
1359 dest->throttle_trigger_threshold = params->throttle_trigger_threshold;
1360 }
1361
1362 if (params->has_cpu_throttle_initial) {
1363 dest->cpu_throttle_initial = params->cpu_throttle_initial;
1364 }
1365
1366 if (params->has_cpu_throttle_increment) {
1367 dest->cpu_throttle_increment = params->cpu_throttle_increment;
1368 }
1369
1370 if (params->has_cpu_throttle_tailslow) {
1371 dest->cpu_throttle_tailslow = params->cpu_throttle_tailslow;
1372 }
1373
1374 if (params->has_tls_creds) {
1375 assert(params->tls_creds->type == QTYPE_QSTRING);
1376 dest->tls_creds = params->tls_creds->u.s;
1377 }
1378
1379 if (params->has_tls_hostname) {
1380 assert(params->tls_hostname->type == QTYPE_QSTRING);
1381 dest->tls_hostname = params->tls_hostname->u.s;
1382 }
1383
1384 if (params->has_max_bandwidth) {
1385 dest->max_bandwidth = params->max_bandwidth;
1386 }
1387
1388 if (params->has_downtime_limit) {
1389 dest->downtime_limit = params->downtime_limit;
1390 }
1391
1392 if (params->has_x_checkpoint_delay) {
1393 dest->x_checkpoint_delay = params->x_checkpoint_delay;
1394 }
1395
1396 if (params->has_block_incremental) {
1397 dest->block_incremental = params->block_incremental;
1398 }
1399 if (params->has_multifd_channels) {
1400 dest->multifd_channels = params->multifd_channels;
1401 }
1402 if (params->has_multifd_compression) {
1403 dest->multifd_compression = params->multifd_compression;
1404 }
1405 if (params->has_xbzrle_cache_size) {
1406 dest->xbzrle_cache_size = params->xbzrle_cache_size;
1407 }
1408 if (params->has_max_postcopy_bandwidth) {
1409 dest->max_postcopy_bandwidth = params->max_postcopy_bandwidth;
1410 }
1411 if (params->has_max_cpu_throttle) {
1412 dest->max_cpu_throttle = params->max_cpu_throttle;
1413 }
1414 if (params->has_announce_initial) {
1415 dest->announce_initial = params->announce_initial;
1416 }
1417 if (params->has_announce_max) {
1418 dest->announce_max = params->announce_max;
1419 }
1420 if (params->has_announce_rounds) {
1421 dest->announce_rounds = params->announce_rounds;
1422 }
1423 if (params->has_announce_step) {
1424 dest->announce_step = params->announce_step;
1425 }
1426
1427 if (params->has_block_bitmap_mapping) {
1428 dest->has_block_bitmap_mapping = true;
1429 dest->block_bitmap_mapping = params->block_bitmap_mapping;
1430 }
1431 }
1432
1433 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
1434 {
1435 MigrationState *s = migrate_get_current();
1436
1437 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1438
1439 if (params->has_compress_level) {
1440 s->parameters.compress_level = params->compress_level;
1441 }
1442
1443 if (params->has_compress_threads) {
1444 s->parameters.compress_threads = params->compress_threads;
1445 }
1446
1447 if (params->has_compress_wait_thread) {
1448 s->parameters.compress_wait_thread = params->compress_wait_thread;
1449 }
1450
1451 if (params->has_decompress_threads) {
1452 s->parameters.decompress_threads = params->decompress_threads;
1453 }
1454
1455 if (params->has_throttle_trigger_threshold) {
1456 s->parameters.throttle_trigger_threshold = params->throttle_trigger_threshold;
1457 }
1458
1459 if (params->has_cpu_throttle_initial) {
1460 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial;
1461 }
1462
1463 if (params->has_cpu_throttle_increment) {
1464 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment;
1465 }
1466
1467 if (params->has_cpu_throttle_tailslow) {
1468 s->parameters.cpu_throttle_tailslow = params->cpu_throttle_tailslow;
1469 }
1470
1471 if (params->has_tls_creds) {
1472 g_free(s->parameters.tls_creds);
1473 assert(params->tls_creds->type == QTYPE_QSTRING);
1474 s->parameters.tls_creds = g_strdup(params->tls_creds->u.s);
1475 }
1476
1477 if (params->has_tls_hostname) {
1478 g_free(s->parameters.tls_hostname);
1479 assert(params->tls_hostname->type == QTYPE_QSTRING);
1480 s->parameters.tls_hostname = g_strdup(params->tls_hostname->u.s);
1481 }
1482
1483 if (params->has_tls_authz) {
1484 g_free(s->parameters.tls_authz);
1485 assert(params->tls_authz->type == QTYPE_QSTRING);
1486 s->parameters.tls_authz = g_strdup(params->tls_authz->u.s);
1487 }
1488
1489 if (params->has_max_bandwidth) {
1490 s->parameters.max_bandwidth = params->max_bandwidth;
1491 if (s->to_dst_file && !migration_in_postcopy()) {
1492 qemu_file_set_rate_limit(s->to_dst_file,
1493 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
1494 }
1495 }
1496
1497 if (params->has_downtime_limit) {
1498 s->parameters.downtime_limit = params->downtime_limit;
1499 }
1500
1501 if (params->has_x_checkpoint_delay) {
1502 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay;
1503 if (migration_in_colo_state()) {
1504 colo_checkpoint_notify(s);
1505 }
1506 }
1507
1508 if (params->has_block_incremental) {
1509 s->parameters.block_incremental = params->block_incremental;
1510 }
1511 if (params->has_multifd_channels) {
1512 s->parameters.multifd_channels = params->multifd_channels;
1513 }
1514 if (params->has_multifd_compression) {
1515 s->parameters.multifd_compression = params->multifd_compression;
1516 }
1517 if (params->has_xbzrle_cache_size) {
1518 s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
1519 xbzrle_cache_resize(params->xbzrle_cache_size, errp);
1520 }
1521 if (params->has_max_postcopy_bandwidth) {
1522 s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth;
1523 if (s->to_dst_file && migration_in_postcopy()) {
1524 qemu_file_set_rate_limit(s->to_dst_file,
1525 s->parameters.max_postcopy_bandwidth / XFER_LIMIT_RATIO);
1526 }
1527 }
1528 if (params->has_max_cpu_throttle) {
1529 s->parameters.max_cpu_throttle = params->max_cpu_throttle;
1530 }
1531 if (params->has_announce_initial) {
1532 s->parameters.announce_initial = params->announce_initial;
1533 }
1534 if (params->has_announce_max) {
1535 s->parameters.announce_max = params->announce_max;
1536 }
1537 if (params->has_announce_rounds) {
1538 s->parameters.announce_rounds = params->announce_rounds;
1539 }
1540 if (params->has_announce_step) {
1541 s->parameters.announce_step = params->announce_step;
1542 }
1543
1544 if (params->has_block_bitmap_mapping) {
1545 qapi_free_BitmapMigrationNodeAliasList(
1546 s->parameters.block_bitmap_mapping);
1547
1548 s->parameters.has_block_bitmap_mapping = true;
1549 s->parameters.block_bitmap_mapping =
1550 QAPI_CLONE(BitmapMigrationNodeAliasList,
1551 params->block_bitmap_mapping);
1552 }
1553 }
1554
1555 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
1556 {
1557 MigrationParameters tmp;
1558
1559 /* TODO Rewrite "" to null instead */
1560 if (params->has_tls_creds
1561 && params->tls_creds->type == QTYPE_QNULL) {
1562 qobject_unref(params->tls_creds->u.n);
1563 params->tls_creds->type = QTYPE_QSTRING;
1564 params->tls_creds->u.s = strdup("");
1565 }
1566 /* TODO Rewrite "" to null instead */
1567 if (params->has_tls_hostname
1568 && params->tls_hostname->type == QTYPE_QNULL) {
1569 qobject_unref(params->tls_hostname->u.n);
1570 params->tls_hostname->type = QTYPE_QSTRING;
1571 params->tls_hostname->u.s = strdup("");
1572 }
1573
1574 migrate_params_test_apply(params, &tmp);
1575
1576 if (!migrate_params_check(&tmp, errp)) {
1577 /* Invalid parameter */
1578 return;
1579 }
1580
1581 migrate_params_apply(params, errp);
1582 }
1583
1584
1585 void qmp_migrate_start_postcopy(Error **errp)
1586 {
1587 MigrationState *s = migrate_get_current();
1588
1589 if (!migrate_postcopy()) {
1590 error_setg(errp, "Enable postcopy with migrate_set_capability before"
1591 " the start of migration");
1592 return;
1593 }
1594
1595 if (s->state == MIGRATION_STATUS_NONE) {
1596 error_setg(errp, "Postcopy must be started after migration has been"
1597 " started");
1598 return;
1599 }
1600 /*
1601 * we don't error if migration has finished since that would be racy
1602 * with issuing this command.
1603 */
1604 qatomic_set(&s->start_postcopy, true);
1605 }
1606
1607 /* shared migration helpers */
1608
1609 void migrate_set_state(int *state, int old_state, int new_state)
1610 {
1611 assert(new_state < MIGRATION_STATUS__MAX);
1612 if (qatomic_cmpxchg(state, old_state, new_state) == old_state) {
1613 trace_migrate_set_state(MigrationStatus_str(new_state));
1614 migrate_generate_event(new_state);
1615 }
1616 }
1617
1618 static MigrationCapabilityStatusList *migrate_cap_add(
1619 MigrationCapabilityStatusList *list,
1620 MigrationCapability index,
1621 bool state)
1622 {
1623 MigrationCapabilityStatusList *cap;
1624
1625 cap = g_new0(MigrationCapabilityStatusList, 1);
1626 cap->value = g_new0(MigrationCapabilityStatus, 1);
1627 cap->value->capability = index;
1628 cap->value->state = state;
1629 cap->next = list;
1630
1631 return cap;
1632 }
1633
1634 void migrate_set_block_enabled(bool value, Error **errp)
1635 {
1636 MigrationCapabilityStatusList *cap;
1637
1638 cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value);
1639 qmp_migrate_set_capabilities(cap, errp);
1640 qapi_free_MigrationCapabilityStatusList(cap);
1641 }
1642
1643 static void migrate_set_block_incremental(MigrationState *s, bool value)
1644 {
1645 s->parameters.block_incremental = value;
1646 }
1647
1648 static void block_cleanup_parameters(MigrationState *s)
1649 {
1650 if (s->must_remove_block_options) {
1651 /* setting to false can never fail */
1652 migrate_set_block_enabled(false, &error_abort);
1653 migrate_set_block_incremental(s, false);
1654 s->must_remove_block_options = false;
1655 }
1656 }
1657
1658 static void migrate_fd_cleanup(MigrationState *s)
1659 {
1660 qemu_bh_delete(s->cleanup_bh);
1661 s->cleanup_bh = NULL;
1662
1663 qemu_savevm_state_cleanup();
1664
1665 if (s->to_dst_file) {
1666 QEMUFile *tmp;
1667
1668 trace_migrate_fd_cleanup();
1669 qemu_mutex_unlock_iothread();
1670 if (s->migration_thread_running) {
1671 qemu_thread_join(&s->thread);
1672 s->migration_thread_running = false;
1673 }
1674 qemu_mutex_lock_iothread();
1675
1676 multifd_save_cleanup();
1677 qemu_mutex_lock(&s->qemu_file_lock);
1678 tmp = s->to_dst_file;
1679 s->to_dst_file = NULL;
1680 qemu_mutex_unlock(&s->qemu_file_lock);
1681 /*
1682 * Close the file handle without the lock to make sure the
1683 * critical section won't block for long.
1684 */
1685 qemu_fclose(tmp);
1686 }
1687
1688 assert(!migration_is_active(s));
1689
1690 if (s->state == MIGRATION_STATUS_CANCELLING) {
1691 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
1692 MIGRATION_STATUS_CANCELLED);
1693 }
1694
1695 if (s->error) {
1696 /* It is used on info migrate. We can't free it */
1697 error_report_err(error_copy(s->error));
1698 }
1699 notifier_list_notify(&migration_state_notifiers, s);
1700 block_cleanup_parameters(s);
1701 }
1702
1703 static void migrate_fd_cleanup_schedule(MigrationState *s)
1704 {
1705 /*
1706 * Ref the state for bh, because it may be called when
1707 * there're already no other refs
1708 */
1709 object_ref(OBJECT(s));
1710 qemu_bh_schedule(s->cleanup_bh);
1711 }
1712
1713 static void migrate_fd_cleanup_bh(void *opaque)
1714 {
1715 MigrationState *s = opaque;
1716 migrate_fd_cleanup(s);
1717 object_unref(OBJECT(s));
1718 }
1719
1720 void migrate_set_error(MigrationState *s, const Error *error)
1721 {
1722 QEMU_LOCK_GUARD(&s->error_mutex);
1723 if (!s->error) {
1724 s->error = error_copy(error);
1725 }
1726 }
1727
1728 void migrate_fd_error(MigrationState *s, const Error *error)
1729 {
1730 trace_migrate_fd_error(error_get_pretty(error));
1731 assert(s->to_dst_file == NULL);
1732 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1733 MIGRATION_STATUS_FAILED);
1734 migrate_set_error(s, error);
1735 }
1736
1737 static void migrate_fd_cancel(MigrationState *s)
1738 {
1739 int old_state ;
1740 QEMUFile *f = migrate_get_current()->to_dst_file;
1741 trace_migrate_fd_cancel();
1742
1743 if (s->rp_state.from_dst_file) {
1744 /* shutdown the rp socket, so causing the rp thread to shutdown */
1745 qemu_file_shutdown(s->rp_state.from_dst_file);
1746 }
1747
1748 do {
1749 old_state = s->state;
1750 if (!migration_is_running(old_state)) {
1751 break;
1752 }
1753 /* If the migration is paused, kick it out of the pause */
1754 if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) {
1755 qemu_sem_post(&s->pause_sem);
1756 }
1757 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
1758 } while (s->state != MIGRATION_STATUS_CANCELLING);
1759
1760 /*
1761 * If we're unlucky the migration code might be stuck somewhere in a
1762 * send/write while the network has failed and is waiting to timeout;
1763 * if we've got shutdown(2) available then we can force it to quit.
1764 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1765 * called in a bh, so there is no race against this cancel.
1766 */
1767 if (s->state == MIGRATION_STATUS_CANCELLING && f) {
1768 qemu_file_shutdown(f);
1769 }
1770 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
1771 Error *local_err = NULL;
1772
1773 bdrv_invalidate_cache_all(&local_err);
1774 if (local_err) {
1775 error_report_err(local_err);
1776 } else {
1777 s->block_inactive = false;
1778 }
1779 }
1780 }
1781
1782 void add_migration_state_change_notifier(Notifier *notify)
1783 {
1784 notifier_list_add(&migration_state_notifiers, notify);
1785 }
1786
1787 void remove_migration_state_change_notifier(Notifier *notify)
1788 {
1789 notifier_remove(notify);
1790 }
1791
1792 bool migration_in_setup(MigrationState *s)
1793 {
1794 return s->state == MIGRATION_STATUS_SETUP;
1795 }
1796
1797 bool migration_has_finished(MigrationState *s)
1798 {
1799 return s->state == MIGRATION_STATUS_COMPLETED;
1800 }
1801
1802 bool migration_has_failed(MigrationState *s)
1803 {
1804 return (s->state == MIGRATION_STATUS_CANCELLED ||
1805 s->state == MIGRATION_STATUS_FAILED);
1806 }
1807
1808 bool migration_in_postcopy(void)
1809 {
1810 MigrationState *s = migrate_get_current();
1811
1812 switch (s->state) {
1813 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1814 case MIGRATION_STATUS_POSTCOPY_PAUSED:
1815 case MIGRATION_STATUS_POSTCOPY_RECOVER:
1816 return true;
1817 default:
1818 return false;
1819 }
1820 }
1821
1822 bool migration_in_postcopy_after_devices(MigrationState *s)
1823 {
1824 return migration_in_postcopy() && s->postcopy_after_devices;
1825 }
1826
1827 bool migration_in_incoming_postcopy(void)
1828 {
1829 PostcopyState ps = postcopy_state_get();
1830
1831 return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END;
1832 }
1833
1834 bool migration_is_idle(void)
1835 {
1836 MigrationState *s = current_migration;
1837
1838 if (!s) {
1839 return true;
1840 }
1841
1842 switch (s->state) {
1843 case MIGRATION_STATUS_NONE:
1844 case MIGRATION_STATUS_CANCELLED:
1845 case MIGRATION_STATUS_COMPLETED:
1846 case MIGRATION_STATUS_FAILED:
1847 return true;
1848 case MIGRATION_STATUS_SETUP:
1849 case MIGRATION_STATUS_CANCELLING:
1850 case MIGRATION_STATUS_ACTIVE:
1851 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1852 case MIGRATION_STATUS_COLO:
1853 case MIGRATION_STATUS_PRE_SWITCHOVER:
1854 case MIGRATION_STATUS_DEVICE:
1855 case MIGRATION_STATUS_WAIT_UNPLUG:
1856 return false;
1857 case MIGRATION_STATUS__MAX:
1858 g_assert_not_reached();
1859 }
1860
1861 return false;
1862 }
1863
1864 bool migration_is_active(MigrationState *s)
1865 {
1866 return (s->state == MIGRATION_STATUS_ACTIVE ||
1867 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
1868 }
1869
1870 void migrate_init(MigrationState *s)
1871 {
1872 /*
1873 * Reinitialise all migration state, except
1874 * parameters/capabilities that the user set, and
1875 * locks.
1876 */
1877 s->cleanup_bh = 0;
1878 s->to_dst_file = NULL;
1879 s->state = MIGRATION_STATUS_NONE;
1880 s->rp_state.from_dst_file = NULL;
1881 s->rp_state.error = false;
1882 s->mbps = 0.0;
1883 s->pages_per_second = 0.0;
1884 s->downtime = 0;
1885 s->expected_downtime = 0;
1886 s->setup_time = 0;
1887 s->start_postcopy = false;
1888 s->postcopy_after_devices = false;
1889 s->migration_thread_running = false;
1890 error_free(s->error);
1891 s->error = NULL;
1892 s->hostname = NULL;
1893
1894 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
1895
1896 s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1897 s->total_time = 0;
1898 s->vm_was_running = false;
1899 s->iteration_initial_bytes = 0;
1900 s->threshold_size = 0;
1901 }
1902
1903 static GSList *migration_blockers;
1904
1905 int migrate_add_blocker(Error *reason, Error **errp)
1906 {
1907 if (only_migratable) {
1908 error_propagate_prepend(errp, error_copy(reason),
1909 "disallowing migration blocker "
1910 "(--only-migratable) for: ");
1911 return -EACCES;
1912 }
1913
1914 if (migration_is_idle()) {
1915 migration_blockers = g_slist_prepend(migration_blockers, reason);
1916 return 0;
1917 }
1918
1919 error_propagate_prepend(errp, error_copy(reason),
1920 "disallowing migration blocker "
1921 "(migration in progress) for: ");
1922 return -EBUSY;
1923 }
1924
1925 void migrate_del_blocker(Error *reason)
1926 {
1927 migration_blockers = g_slist_remove(migration_blockers, reason);
1928 }
1929
1930 void qmp_migrate_incoming(const char *uri, Error **errp)
1931 {
1932 Error *local_err = NULL;
1933 static bool once = true;
1934
1935 if (!deferred_incoming) {
1936 error_setg(errp, "For use with '-incoming defer'");
1937 return;
1938 }
1939 if (!once) {
1940 error_setg(errp, "The incoming migration has already been started");
1941 return;
1942 }
1943
1944 qemu_start_incoming_migration(uri, &local_err);
1945
1946 if (local_err) {
1947 error_propagate(errp, local_err);
1948 return;
1949 }
1950
1951 once = false;
1952 }
1953
1954 void qmp_migrate_recover(const char *uri, Error **errp)
1955 {
1956 MigrationIncomingState *mis = migration_incoming_get_current();
1957
1958 if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
1959 error_setg(errp, "Migrate recover can only be run "
1960 "when postcopy is paused.");
1961 return;
1962 }
1963
1964 if (qatomic_cmpxchg(&mis->postcopy_recover_triggered,
1965 false, true) == true) {
1966 error_setg(errp, "Migrate recovery is triggered already");
1967 return;
1968 }
1969
1970 /*
1971 * Note that this call will never start a real migration; it will
1972 * only re-setup the migration stream and poke existing migration
1973 * to continue using that newly established channel.
1974 */
1975 qemu_start_incoming_migration(uri, errp);
1976 }
1977
1978 void qmp_migrate_pause(Error **errp)
1979 {
1980 MigrationState *ms = migrate_get_current();
1981 MigrationIncomingState *mis = migration_incoming_get_current();
1982 int ret;
1983
1984 if (ms->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
1985 /* Source side, during postcopy */
1986 qemu_mutex_lock(&ms->qemu_file_lock);
1987 ret = qemu_file_shutdown(ms->to_dst_file);
1988 qemu_mutex_unlock(&ms->qemu_file_lock);
1989 if (ret) {
1990 error_setg(errp, "Failed to pause source migration");
1991 }
1992 return;
1993 }
1994
1995 if (mis->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
1996 ret = qemu_file_shutdown(mis->from_src_file);
1997 if (ret) {
1998 error_setg(errp, "Failed to pause destination migration");
1999 }
2000 return;
2001 }
2002
2003 error_setg(errp, "migrate-pause is currently only supported "
2004 "during postcopy-active state");
2005 }
2006
2007 bool migration_is_blocked(Error **errp)
2008 {
2009 if (qemu_savevm_state_blocked(errp)) {
2010 return true;
2011 }
2012
2013 if (migration_blockers) {
2014 error_propagate(errp, error_copy(migration_blockers->data));
2015 return true;
2016 }
2017
2018 return false;
2019 }
2020
2021 /* Returns true if continue to migrate, or false if error detected */
2022 static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
2023 bool resume, Error **errp)
2024 {
2025 Error *local_err = NULL;
2026
2027 if (resume) {
2028 if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
2029 error_setg(errp, "Cannot resume if there is no "
2030 "paused migration");
2031 return false;
2032 }
2033
2034 /*
2035 * Postcopy recovery won't work well with release-ram
2036 * capability since release-ram will drop the page buffer as
2037 * long as the page is put into the send buffer. So if there
2038 * is a network failure happened, any page buffers that have
2039 * not yet reached the destination VM but have already been
2040 * sent from the source VM will be lost forever. Let's refuse
2041 * the client from resuming such a postcopy migration.
2042 * Luckily release-ram was designed to only be used when src
2043 * and destination VMs are on the same host, so it should be
2044 * fine.
2045 */
2046 if (migrate_release_ram()) {
2047 error_setg(errp, "Postcopy recovery cannot work "
2048 "when release-ram capability is set");
2049 return false;
2050 }
2051
2052 /* This is a resume, skip init status */
2053 return true;
2054 }
2055
2056 if (migration_is_running(s->state)) {
2057 error_setg(errp, QERR_MIGRATION_ACTIVE);
2058 return false;
2059 }
2060
2061 if (runstate_check(RUN_STATE_INMIGRATE)) {
2062 error_setg(errp, "Guest is waiting for an incoming migration");
2063 return false;
2064 }
2065
2066 if (migration_is_blocked(errp)) {
2067 return false;
2068 }
2069
2070 if (blk || blk_inc) {
2071 if (migrate_use_block() || migrate_use_block_incremental()) {
2072 error_setg(errp, "Command options are incompatible with "
2073 "current migration capabilities");
2074 return false;
2075 }
2076 migrate_set_block_enabled(true, &local_err);
2077 if (local_err) {
2078 error_propagate(errp, local_err);
2079 return false;
2080 }
2081 s->must_remove_block_options = true;
2082 }
2083
2084 if (blk_inc) {
2085 migrate_set_block_incremental(s, true);
2086 }
2087
2088 migrate_init(s);
2089 /*
2090 * set ram_counters memory to zero for a
2091 * new migration
2092 */
2093 memset(&ram_counters, 0, sizeof(ram_counters));
2094
2095 return true;
2096 }
2097
2098 void qmp_migrate(const char *uri, bool has_blk, bool blk,
2099 bool has_inc, bool inc, bool has_detach, bool detach,
2100 bool has_resume, bool resume, Error **errp)
2101 {
2102 Error *local_err = NULL;
2103 MigrationState *s = migrate_get_current();
2104 const char *p = NULL;
2105
2106 if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
2107 has_resume && resume, errp)) {
2108 /* Error detected, put into errp */
2109 return;
2110 }
2111
2112 if (strstart(uri, "tcp:", &p) ||
2113 strstart(uri, "unix:", NULL) ||
2114 strstart(uri, "vsock:", NULL)) {
2115 socket_start_outgoing_migration(s, p ? p : uri, &local_err);
2116 #ifdef CONFIG_RDMA
2117 } else if (strstart(uri, "rdma:", &p)) {
2118 rdma_start_outgoing_migration(s, p, &local_err);
2119 #endif
2120 } else if (strstart(uri, "exec:", &p)) {
2121 exec_start_outgoing_migration(s, p, &local_err);
2122 } else if (strstart(uri, "fd:", &p)) {
2123 fd_start_outgoing_migration(s, p, &local_err);
2124 } else {
2125 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
2126 "a valid migration protocol");
2127 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2128 MIGRATION_STATUS_FAILED);
2129 block_cleanup_parameters(s);
2130 return;
2131 }
2132
2133 if (local_err) {
2134 migrate_fd_error(s, local_err);
2135 error_propagate(errp, local_err);
2136 return;
2137 }
2138 }
2139
2140 void qmp_migrate_cancel(Error **errp)
2141 {
2142 migrate_fd_cancel(migrate_get_current());
2143 }
2144
2145 void qmp_migrate_continue(MigrationStatus state, Error **errp)
2146 {
2147 MigrationState *s = migrate_get_current();
2148 if (s->state != state) {
2149 error_setg(errp, "Migration not in expected state: %s",
2150 MigrationStatus_str(s->state));
2151 return;
2152 }
2153 qemu_sem_post(&s->pause_sem);
2154 }
2155
2156 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
2157 {
2158 MigrateSetParameters p = {
2159 .has_xbzrle_cache_size = true,
2160 .xbzrle_cache_size = value,
2161 };
2162
2163 qmp_migrate_set_parameters(&p, errp);
2164 }
2165
2166 int64_t qmp_query_migrate_cache_size(Error **errp)
2167 {
2168 return migrate_xbzrle_cache_size();
2169 }
2170
2171 void qmp_migrate_set_speed(int64_t value, Error **errp)
2172 {
2173 MigrateSetParameters p = {
2174 .has_max_bandwidth = true,
2175 .max_bandwidth = value,
2176 };
2177
2178 qmp_migrate_set_parameters(&p, errp);
2179 }
2180
2181 void qmp_migrate_set_downtime(double value, Error **errp)
2182 {
2183 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) {
2184 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
2185 "downtime_limit",
2186 "an integer in the range of 0 to "
2187 stringify(MAX_MIGRATE_DOWNTIME_SECONDS)" seconds");
2188 return;
2189 }
2190
2191 value *= 1000; /* Convert to milliseconds */
2192
2193 MigrateSetParameters p = {
2194 .has_downtime_limit = true,
2195 .downtime_limit = (int64_t)value,
2196 };
2197
2198 qmp_migrate_set_parameters(&p, errp);
2199 }
2200
2201 bool migrate_release_ram(void)
2202 {
2203 MigrationState *s;
2204
2205 s = migrate_get_current();
2206
2207 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM];
2208 }
2209
2210 bool migrate_postcopy_ram(void)
2211 {
2212 MigrationState *s;
2213
2214 s = migrate_get_current();
2215
2216 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM];
2217 }
2218
2219 bool migrate_postcopy(void)
2220 {
2221 return migrate_postcopy_ram() || migrate_dirty_bitmaps();
2222 }
2223
2224 bool migrate_auto_converge(void)
2225 {
2226 MigrationState *s;
2227
2228 s = migrate_get_current();
2229
2230 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
2231 }
2232
2233 bool migrate_zero_blocks(void)
2234 {
2235 MigrationState *s;
2236
2237 s = migrate_get_current();
2238
2239 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
2240 }
2241
2242 bool migrate_postcopy_blocktime(void)
2243 {
2244 MigrationState *s;
2245
2246 s = migrate_get_current();
2247
2248 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME];
2249 }
2250
2251 bool migrate_use_compression(void)
2252 {
2253 MigrationState *s;
2254
2255 s = migrate_get_current();
2256
2257 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
2258 }
2259
2260 int migrate_compress_level(void)
2261 {
2262 MigrationState *s;
2263
2264 s = migrate_get_current();
2265
2266 return s->parameters.compress_level;
2267 }
2268
2269 int migrate_compress_threads(void)
2270 {
2271 MigrationState *s;
2272
2273 s = migrate_get_current();
2274
2275 return s->parameters.compress_threads;
2276 }
2277
2278 int migrate_compress_wait_thread(void)
2279 {
2280 MigrationState *s;
2281
2282 s = migrate_get_current();
2283
2284 return s->parameters.compress_wait_thread;
2285 }
2286
2287 int migrate_decompress_threads(void)
2288 {
2289 MigrationState *s;
2290
2291 s = migrate_get_current();
2292
2293 return s->parameters.decompress_threads;
2294 }
2295
2296 bool migrate_dirty_bitmaps(void)
2297 {
2298 MigrationState *s;
2299
2300 s = migrate_get_current();
2301
2302 return s->enabled_capabilities[MIGRATION_CAPABILITY_DIRTY_BITMAPS];
2303 }
2304
2305 bool migrate_ignore_shared(void)
2306 {
2307 MigrationState *s;
2308
2309 s = migrate_get_current();
2310
2311 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_IGNORE_SHARED];
2312 }
2313
2314 bool migrate_validate_uuid(void)
2315 {
2316 MigrationState *s;
2317
2318 s = migrate_get_current();
2319
2320 return s->enabled_capabilities[MIGRATION_CAPABILITY_VALIDATE_UUID];
2321 }
2322
2323 bool migrate_use_events(void)
2324 {
2325 MigrationState *s;
2326
2327 s = migrate_get_current();
2328
2329 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
2330 }
2331
2332 bool migrate_use_multifd(void)
2333 {
2334 MigrationState *s;
2335
2336 s = migrate_get_current();
2337
2338 return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD];
2339 }
2340
2341 bool migrate_pause_before_switchover(void)
2342 {
2343 MigrationState *s;
2344
2345 s = migrate_get_current();
2346
2347 return s->enabled_capabilities[
2348 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
2349 }
2350
2351 int migrate_multifd_channels(void)
2352 {
2353 MigrationState *s;
2354
2355 s = migrate_get_current();
2356
2357 return s->parameters.multifd_channels;
2358 }
2359
2360 MultiFDCompression migrate_multifd_compression(void)
2361 {
2362 MigrationState *s;
2363
2364 s = migrate_get_current();
2365
2366 return s->parameters.multifd_compression;
2367 }
2368
2369 int migrate_multifd_zlib_level(void)
2370 {
2371 MigrationState *s;
2372
2373 s = migrate_get_current();
2374
2375 return s->parameters.multifd_zlib_level;
2376 }
2377
2378 int migrate_multifd_zstd_level(void)
2379 {
2380 MigrationState *s;
2381
2382 s = migrate_get_current();
2383
2384 return s->parameters.multifd_zstd_level;
2385 }
2386
2387 int migrate_use_xbzrle(void)
2388 {
2389 MigrationState *s;
2390
2391 s = migrate_get_current();
2392
2393 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
2394 }
2395
2396 int64_t migrate_xbzrle_cache_size(void)
2397 {
2398 MigrationState *s;
2399
2400 s = migrate_get_current();
2401
2402 return s->parameters.xbzrle_cache_size;
2403 }
2404
2405 static int64_t migrate_max_postcopy_bandwidth(void)
2406 {
2407 MigrationState *s;
2408
2409 s = migrate_get_current();
2410
2411 return s->parameters.max_postcopy_bandwidth;
2412 }
2413
2414 bool migrate_use_block(void)
2415 {
2416 MigrationState *s;
2417
2418 s = migrate_get_current();
2419
2420 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK];
2421 }
2422
2423 bool migrate_use_return_path(void)
2424 {
2425 MigrationState *s;
2426
2427 s = migrate_get_current();
2428
2429 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH];
2430 }
2431
2432 bool migrate_use_block_incremental(void)
2433 {
2434 MigrationState *s;
2435
2436 s = migrate_get_current();
2437
2438 return s->parameters.block_incremental;
2439 }
2440
2441 /* migration thread support */
2442 /*
2443 * Something bad happened to the RP stream, mark an error
2444 * The caller shall print or trace something to indicate why
2445 */
2446 static void mark_source_rp_bad(MigrationState *s)
2447 {
2448 s->rp_state.error = true;
2449 }
2450
2451 static struct rp_cmd_args {
2452 ssize_t len; /* -1 = variable */
2453 const char *name;
2454 } rp_cmd_args[] = {
2455 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
2456 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
2457 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
2458 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
2459 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
2460 [MIG_RP_MSG_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
2461 [MIG_RP_MSG_RESUME_ACK] = { .len = 4, .name = "RESUME_ACK" },
2462 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
2463 };
2464
2465 /*
2466 * Process a request for pages received on the return path,
2467 * We're allowed to send more than requested (e.g. to round to our page size)
2468 * and we don't need to send pages that have already been sent.
2469 */
2470 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
2471 ram_addr_t start, size_t len)
2472 {
2473 long our_host_ps = qemu_real_host_page_size;
2474
2475 trace_migrate_handle_rp_req_pages(rbname, start, len);
2476
2477 /*
2478 * Since we currently insist on matching page sizes, just sanity check
2479 * we're being asked for whole host pages.
2480 */
2481 if (start & (our_host_ps-1) ||
2482 (len & (our_host_ps-1))) {
2483 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
2484 " len: %zd", __func__, start, len);
2485 mark_source_rp_bad(ms);
2486 return;
2487 }
2488
2489 if (ram_save_queue_pages(rbname, start, len)) {
2490 mark_source_rp_bad(ms);
2491 }
2492 }
2493
2494 /* Return true to retry, false to quit */
2495 static bool postcopy_pause_return_path_thread(MigrationState *s)
2496 {
2497 trace_postcopy_pause_return_path();
2498
2499 qemu_sem_wait(&s->postcopy_pause_rp_sem);
2500
2501 trace_postcopy_pause_return_path_continued();
2502
2503 return true;
2504 }
2505
2506 static int migrate_handle_rp_recv_bitmap(MigrationState *s, char *block_name)
2507 {
2508 RAMBlock *block = qemu_ram_block_by_name(block_name);
2509
2510 if (!block) {
2511 error_report("%s: invalid block name '%s'", __func__, block_name);
2512 return -EINVAL;
2513 }
2514
2515 /* Fetch the received bitmap and refresh the dirty bitmap */
2516 return ram_dirty_bitmap_reload(s, block);
2517 }
2518
2519 static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value)
2520 {
2521 trace_source_return_path_thread_resume_ack(value);
2522
2523 if (value != MIGRATION_RESUME_ACK_VALUE) {
2524 error_report("%s: illegal resume_ack value %"PRIu32,
2525 __func__, value);
2526 return -1;
2527 }
2528
2529 /* Now both sides are active. */
2530 migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
2531 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2532
2533 /* Notify send thread that time to continue send pages */
2534 qemu_sem_post(&s->rp_state.rp_sem);
2535
2536 return 0;
2537 }
2538
2539 /*
2540 * Handles messages sent on the return path towards the source VM
2541 *
2542 */
2543 static void *source_return_path_thread(void *opaque)
2544 {
2545 MigrationState *ms = opaque;
2546 QEMUFile *rp = ms->rp_state.from_dst_file;
2547 uint16_t header_len, header_type;
2548 uint8_t buf[512];
2549 uint32_t tmp32, sibling_error;
2550 ram_addr_t start = 0; /* =0 to silence warning */
2551 size_t len = 0, expected_len;
2552 int res;
2553
2554 trace_source_return_path_thread_entry();
2555 rcu_register_thread();
2556
2557 retry:
2558 while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
2559 migration_is_setup_or_active(ms->state)) {
2560 trace_source_return_path_thread_loop_top();
2561 header_type = qemu_get_be16(rp);
2562 header_len = qemu_get_be16(rp);
2563
2564 if (qemu_file_get_error(rp)) {
2565 mark_source_rp_bad(ms);
2566 goto out;
2567 }
2568
2569 if (header_type >= MIG_RP_MSG_MAX ||
2570 header_type == MIG_RP_MSG_INVALID) {
2571 error_report("RP: Received invalid message 0x%04x length 0x%04x",
2572 header_type, header_len);
2573 mark_source_rp_bad(ms);
2574 goto out;
2575 }
2576
2577 if ((rp_cmd_args[header_type].len != -1 &&
2578 header_len != rp_cmd_args[header_type].len) ||
2579 header_len > sizeof(buf)) {
2580 error_report("RP: Received '%s' message (0x%04x) with"
2581 "incorrect length %d expecting %zu",
2582 rp_cmd_args[header_type].name, header_type, header_len,
2583 (size_t)rp_cmd_args[header_type].len);
2584 mark_source_rp_bad(ms);
2585 goto out;
2586 }
2587
2588 /* We know we've got a valid header by this point */
2589 res = qemu_get_buffer(rp, buf, header_len);
2590 if (res != header_len) {
2591 error_report("RP: Failed reading data for message 0x%04x"
2592 " read %d expected %d",
2593 header_type, res, header_len);
2594 mark_source_rp_bad(ms);
2595 goto out;
2596 }
2597
2598 /* OK, we have the message and the data */
2599 switch (header_type) {
2600 case MIG_RP_MSG_SHUT:
2601 sibling_error = ldl_be_p(buf);
2602 trace_source_return_path_thread_shut(sibling_error);
2603 if (sibling_error) {
2604 error_report("RP: Sibling indicated error %d", sibling_error);
2605 mark_source_rp_bad(ms);
2606 }
2607 /*
2608 * We'll let the main thread deal with closing the RP
2609 * we could do a shutdown(2) on it, but we're the only user
2610 * anyway, so there's nothing gained.
2611 */
2612 goto out;
2613
2614 case MIG_RP_MSG_PONG:
2615 tmp32 = ldl_be_p(buf);
2616 trace_source_return_path_thread_pong(tmp32);
2617 break;
2618
2619 case MIG_RP_MSG_REQ_PAGES:
2620 start = ldq_be_p(buf);
2621 len = ldl_be_p(buf + 8);
2622 migrate_handle_rp_req_pages(ms, NULL, start, len);
2623 break;
2624
2625 case MIG_RP_MSG_REQ_PAGES_ID:
2626 expected_len = 12 + 1; /* header + termination */
2627
2628 if (header_len >= expected_len) {
2629 start = ldq_be_p(buf);
2630 len = ldl_be_p(buf + 8);
2631 /* Now we expect an idstr */
2632 tmp32 = buf[12]; /* Length of the following idstr */
2633 buf[13 + tmp32] = '\0';
2634 expected_len += tmp32;
2635 }
2636 if (header_len != expected_len) {
2637 error_report("RP: Req_Page_id with length %d expecting %zd",
2638 header_len, expected_len);
2639 mark_source_rp_bad(ms);
2640 goto out;
2641 }
2642 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
2643 break;
2644
2645 case MIG_RP_MSG_RECV_BITMAP:
2646 if (header_len < 1) {
2647 error_report("%s: missing block name", __func__);
2648 mark_source_rp_bad(ms);
2649 goto out;
2650 }
2651 /* Format: len (1B) + idstr (<255B). This ends the idstr. */
2652 buf[buf[0] + 1] = '\0';
2653 if (migrate_handle_rp_recv_bitmap(ms, (char *)(buf + 1))) {
2654 mark_source_rp_bad(ms);
2655 goto out;
2656 }
2657 break;
2658
2659 case MIG_RP_MSG_RESUME_ACK:
2660 tmp32 = ldl_be_p(buf);
2661 if (migrate_handle_rp_resume_ack(ms, tmp32)) {
2662 mark_source_rp_bad(ms);
2663 goto out;
2664 }
2665 break;
2666
2667 default:
2668 break;
2669 }
2670 }
2671
2672 out:
2673 res = qemu_file_get_error(rp);
2674 if (res) {
2675 if (res == -EIO && migration_in_postcopy()) {
2676 /*
2677 * Maybe there is something we can do: it looks like a
2678 * network down issue, and we pause for a recovery.
2679 */
2680 if (postcopy_pause_return_path_thread(ms)) {
2681 /* Reload rp, reset the rest */
2682 if (rp != ms->rp_state.from_dst_file) {
2683 qemu_fclose(rp);
2684 rp = ms->rp_state.from_dst_file;
2685 }
2686 ms->rp_state.error = false;
2687 goto retry;
2688 }
2689 }
2690
2691 trace_source_return_path_thread_bad_end();
2692 mark_source_rp_bad(ms);
2693 }
2694
2695 trace_source_return_path_thread_end();
2696 ms->rp_state.from_dst_file = NULL;
2697 qemu_fclose(rp);
2698 rcu_unregister_thread();
2699 return NULL;
2700 }
2701
2702 static int open_return_path_on_source(MigrationState *ms,
2703 bool create_thread)
2704 {
2705
2706 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
2707 if (!ms->rp_state.from_dst_file) {
2708 return -1;
2709 }
2710
2711 trace_open_return_path_on_source();
2712
2713 if (!create_thread) {
2714 /* We're done */
2715 return 0;
2716 }
2717
2718 qemu_thread_create(&ms->rp_state.rp_thread, "return path",
2719 source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
2720
2721 trace_open_return_path_on_source_continue();
2722
2723 return 0;
2724 }
2725
2726 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
2727 static int await_return_path_close_on_source(MigrationState *ms)
2728 {
2729 /*
2730 * If this is a normal exit then the destination will send a SHUT and the
2731 * rp_thread will exit, however if there's an error we need to cause
2732 * it to exit.
2733 */
2734 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) {
2735 /*
2736 * shutdown(2), if we have it, will cause it to unblock if it's stuck
2737 * waiting for the destination.
2738 */
2739 qemu_file_shutdown(ms->rp_state.from_dst_file);
2740 mark_source_rp_bad(ms);
2741 }
2742 trace_await_return_path_close_on_source_joining();
2743 qemu_thread_join(&ms->rp_state.rp_thread);
2744 trace_await_return_path_close_on_source_close();
2745 return ms->rp_state.error;
2746 }
2747
2748 /*
2749 * Switch from normal iteration to postcopy
2750 * Returns non-0 on error
2751 */
2752 static int postcopy_start(MigrationState *ms)
2753 {
2754 int ret;
2755 QIOChannelBuffer *bioc;
2756 QEMUFile *fb;
2757 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2758 int64_t bandwidth = migrate_max_postcopy_bandwidth();
2759 bool restart_block = false;
2760 int cur_state = MIGRATION_STATUS_ACTIVE;
2761 if (!migrate_pause_before_switchover()) {
2762 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
2763 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2764 }
2765
2766 trace_postcopy_start();
2767 qemu_mutex_lock_iothread();
2768 trace_postcopy_start_set_run();
2769
2770 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
2771 global_state_store();
2772 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2773 if (ret < 0) {
2774 goto fail;
2775 }
2776
2777 ret = migration_maybe_pause(ms, &cur_state,
2778 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2779 if (ret < 0) {
2780 goto fail;
2781 }
2782
2783 ret = bdrv_inactivate_all();
2784 if (ret < 0) {
2785 goto fail;
2786 }
2787 restart_block = true;
2788
2789 /*
2790 * Cause any non-postcopiable, but iterative devices to
2791 * send out their final data.
2792 */
2793 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false);
2794
2795 /*
2796 * in Finish migrate and with the io-lock held everything should
2797 * be quiet, but we've potentially still got dirty pages and we
2798 * need to tell the destination to throw any pages it's already received
2799 * that are dirty
2800 */
2801 if (migrate_postcopy_ram()) {
2802 if (ram_postcopy_send_discard_bitmap(ms)) {
2803 error_report("postcopy send discard bitmap failed");
2804 goto fail;
2805 }
2806 }
2807
2808 /*
2809 * send rest of state - note things that are doing postcopy
2810 * will notice we're in POSTCOPY_ACTIVE and not actually
2811 * wrap their state up here
2812 */
2813 /* 0 max-postcopy-bandwidth means unlimited */
2814 if (!bandwidth) {
2815 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);
2816 } else {
2817 qemu_file_set_rate_limit(ms->to_dst_file, bandwidth / XFER_LIMIT_RATIO);
2818 }
2819 if (migrate_postcopy_ram()) {
2820 /* Ping just for debugging, helps line traces up */
2821 qemu_savevm_send_ping(ms->to_dst_file, 2);
2822 }
2823
2824 /*
2825 * While loading the device state we may trigger page transfer
2826 * requests and the fd must be free to process those, and thus
2827 * the destination must read the whole device state off the fd before
2828 * it starts processing it. Unfortunately the ad-hoc migration format
2829 * doesn't allow the destination to know the size to read without fully
2830 * parsing it through each devices load-state code (especially the open
2831 * coded devices that use get/put).
2832 * So we wrap the device state up in a package with a length at the start;
2833 * to do this we use a qemu_buf to hold the whole of the device state.
2834 */
2835 bioc = qio_channel_buffer_new(4096);
2836 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");
2837 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
2838 object_unref(OBJECT(bioc));
2839
2840 /*
2841 * Make sure the receiver can get incoming pages before we send the rest
2842 * of the state
2843 */
2844 qemu_savevm_send_postcopy_listen(fb);
2845
2846 qemu_savevm_state_complete_precopy(fb, false, false);
2847 if (migrate_postcopy_ram()) {
2848 qemu_savevm_send_ping(fb, 3);
2849 }
2850
2851 qemu_savevm_send_postcopy_run(fb);
2852
2853 /* <><> end of stuff going into the package */
2854
2855 /* Last point of recovery; as soon as we send the package the destination
2856 * can open devices and potentially start running.
2857 * Lets just check again we've not got any errors.
2858 */
2859 ret = qemu_file_get_error(ms->to_dst_file);
2860 if (ret) {
2861 error_report("postcopy_start: Migration stream errored (pre package)");
2862 goto fail_closefb;
2863 }
2864
2865 restart_block = false;
2866
2867 /* Now send that blob */
2868 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) {
2869 goto fail_closefb;
2870 }
2871 qemu_fclose(fb);
2872
2873 /* Send a notify to give a chance for anything that needs to happen
2874 * at the transition to postcopy and after the device state; in particular
2875 * spice needs to trigger a transition now
2876 */
2877 ms->postcopy_after_devices = true;
2878 notifier_list_notify(&migration_state_notifiers, ms);
2879
2880 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
2881
2882 qemu_mutex_unlock_iothread();
2883
2884 if (migrate_postcopy_ram()) {
2885 /*
2886 * Although this ping is just for debug, it could potentially be
2887 * used for getting a better measurement of downtime at the source.
2888 */
2889 qemu_savevm_send_ping(ms->to_dst_file, 4);
2890 }
2891
2892 if (migrate_release_ram()) {
2893 ram_postcopy_migrated_memory_release(ms);
2894 }
2895
2896 ret = qemu_file_get_error(ms->to_dst_file);
2897 if (ret) {
2898 error_report("postcopy_start: Migration stream errored");
2899 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2900 MIGRATION_STATUS_FAILED);
2901 }
2902
2903 return ret;
2904
2905 fail_closefb:
2906 qemu_fclose(fb);
2907 fail:
2908 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2909 MIGRATION_STATUS_FAILED);
2910 if (restart_block) {
2911 /* A failure happened early enough that we know the destination hasn't
2912 * accessed block devices, so we're safe to recover.
2913 */
2914 Error *local_err = NULL;
2915
2916 bdrv_invalidate_cache_all(&local_err);
2917 if (local_err) {
2918 error_report_err(local_err);
2919 }
2920 }
2921 qemu_mutex_unlock_iothread();
2922 return -1;
2923 }
2924
2925 /**
2926 * migration_maybe_pause: Pause if required to by
2927 * migrate_pause_before_switchover called with the iothread locked
2928 * Returns: 0 on success
2929 */
2930 static int migration_maybe_pause(MigrationState *s,
2931 int *current_active_state,
2932 int new_state)
2933 {
2934 if (!migrate_pause_before_switchover()) {
2935 return 0;
2936 }
2937
2938 /* Since leaving this state is not atomic with posting the semaphore
2939 * it's possible that someone could have issued multiple migrate_continue
2940 * and the semaphore is incorrectly positive at this point;
2941 * the docs say it's undefined to reinit a semaphore that's already
2942 * init'd, so use timedwait to eat up any existing posts.
2943 */
2944 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
2945 /* This block intentionally left blank */
2946 }
2947
2948 /*
2949 * If the migration is cancelled when it is in the completion phase,
2950 * the migration state is set to MIGRATION_STATUS_CANCELLING.
2951 * So we don't need to wait a semaphore, otherwise we would always
2952 * wait for the 'pause_sem' semaphore.
2953 */
2954 if (s->state != MIGRATION_STATUS_CANCELLING) {
2955 qemu_mutex_unlock_iothread();
2956 migrate_set_state(&s->state, *current_active_state,
2957 MIGRATION_STATUS_PRE_SWITCHOVER);
2958 qemu_sem_wait(&s->pause_sem);
2959 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
2960 new_state);
2961 *current_active_state = new_state;
2962 qemu_mutex_lock_iothread();
2963 }
2964
2965 return s->state == new_state ? 0 : -EINVAL;
2966 }
2967
2968 /**
2969 * migration_completion: Used by migration_thread when there's not much left.
2970 * The caller 'breaks' the loop when this returns.
2971 *
2972 * @s: Current migration state
2973 */
2974 static void migration_completion(MigrationState *s)
2975 {
2976 int ret;
2977 int current_active_state = s->state;
2978
2979 if (s->state == MIGRATION_STATUS_ACTIVE) {
2980 qemu_mutex_lock_iothread();
2981 s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2982 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
2983 s->vm_was_running = runstate_is_running();
2984 ret = global_state_store();
2985
2986 if (!ret) {
2987 bool inactivate = !migrate_colo_enabled();
2988 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2989 if (ret >= 0) {
2990 ret = migration_maybe_pause(s, &current_active_state,
2991 MIGRATION_STATUS_DEVICE);
2992 }
2993 if (ret >= 0) {
2994 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
2995 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
2996 inactivate);
2997 }
2998 if (inactivate && ret >= 0) {
2999 s->block_inactive = true;
3000 }
3001 }
3002 qemu_mutex_unlock_iothread();
3003
3004 if (ret < 0) {
3005 goto fail;
3006 }
3007 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
3008 trace_migration_completion_postcopy_end();
3009
3010 qemu_savevm_state_complete_postcopy(s->to_dst_file);
3011 trace_migration_completion_postcopy_end_after_complete();
3012 }
3013
3014 /*
3015 * If rp was opened we must clean up the thread before
3016 * cleaning everything else up (since if there are no failures
3017 * it will wait for the destination to send it's status in
3018 * a SHUT command).
3019 */
3020 if (s->rp_state.from_dst_file) {
3021 int rp_error;
3022 trace_migration_return_path_end_before();
3023 rp_error = await_return_path_close_on_source(s);
3024 trace_migration_return_path_end_after(rp_error);
3025 if (rp_error) {
3026 goto fail_invalidate;
3027 }
3028 }
3029
3030 if (qemu_file_get_error(s->to_dst_file)) {
3031 trace_migration_completion_file_err();
3032 goto fail_invalidate;
3033 }
3034
3035 if (!migrate_colo_enabled()) {
3036 migrate_set_state(&s->state, current_active_state,
3037 MIGRATION_STATUS_COMPLETED);
3038 }
3039
3040 return;
3041
3042 fail_invalidate:
3043 /* If not doing postcopy, vm_start() will be called: let's regain
3044 * control on images.
3045 */
3046 if (s->state == MIGRATION_STATUS_ACTIVE ||
3047 s->state == MIGRATION_STATUS_DEVICE) {
3048 Error *local_err = NULL;
3049
3050 qemu_mutex_lock_iothread();
3051 bdrv_invalidate_cache_all(&local_err);
3052 if (local_err) {
3053 error_report_err(local_err);
3054 } else {
3055 s->block_inactive = false;
3056 }
3057 qemu_mutex_unlock_iothread();
3058 }
3059
3060 fail:
3061 migrate_set_state(&s->state, current_active_state,
3062 MIGRATION_STATUS_FAILED);
3063 }
3064
3065 bool migrate_colo_enabled(void)
3066 {
3067 MigrationState *s = migrate_get_current();
3068 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
3069 }
3070
3071 typedef enum MigThrError {
3072 /* No error detected */
3073 MIG_THR_ERR_NONE = 0,
3074 /* Detected error, but resumed successfully */
3075 MIG_THR_ERR_RECOVERED = 1,
3076 /* Detected fatal error, need to exit */
3077 MIG_THR_ERR_FATAL = 2,
3078 } MigThrError;
3079
3080 static int postcopy_resume_handshake(MigrationState *s)
3081 {
3082 qemu_savevm_send_postcopy_resume(s->to_dst_file);
3083
3084 while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
3085 qemu_sem_wait(&s->rp_state.rp_sem);
3086 }
3087
3088 if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
3089 return 0;
3090 }
3091
3092 return -1;
3093 }
3094
3095 /* Return zero if success, or <0 for error */
3096 static int postcopy_do_resume(MigrationState *s)
3097 {
3098 int ret;
3099
3100 /*
3101 * Call all the resume_prepare() hooks, so that modules can be
3102 * ready for the migration resume.
3103 */
3104 ret = qemu_savevm_state_resume_prepare(s);
3105 if (ret) {
3106 error_report("%s: resume_prepare() failure detected: %d",
3107 __func__, ret);
3108 return ret;
3109 }
3110
3111 /*
3112 * Last handshake with destination on the resume (destination will
3113 * switch to postcopy-active afterwards)
3114 */
3115 ret = postcopy_resume_handshake(s);
3116 if (ret) {
3117 error_report("%s: handshake failed: %d", __func__, ret);
3118 return ret;
3119 }
3120
3121 return 0;
3122 }
3123
3124 /*
3125 * We don't return until we are in a safe state to continue current
3126 * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
3127 * MIG_THR_ERR_FATAL if unrecovery failure happened.
3128 */
3129 static MigThrError postcopy_pause(MigrationState *s)
3130 {
3131 assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
3132
3133 while (true) {
3134 QEMUFile *file;
3135
3136 migrate_set_state(&s->state, s->state,
3137 MIGRATION_STATUS_POSTCOPY_PAUSED);
3138
3139 /* Current channel is possibly broken. Release it. */
3140 assert(s->to_dst_file);
3141 qemu_mutex_lock(&s->qemu_file_lock);
3142 file = s->to_dst_file;
3143 s->to_dst_file = NULL;
3144 qemu_mutex_unlock(&s->qemu_file_lock);
3145
3146 qemu_file_shutdown(file);
3147 qemu_fclose(file);
3148
3149 error_report("Detected IO failure for postcopy. "
3150 "Migration paused.");
3151
3152 /*
3153 * We wait until things fixed up. Then someone will setup the
3154 * status back for us.
3155 */
3156 while (s->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
3157 qemu_sem_wait(&s->postcopy_pause_sem);
3158 }
3159
3160 if (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
3161 /* Woken up by a recover procedure. Give it a shot */
3162
3163 /*
3164 * Firstly, let's wake up the return path now, with a new
3165 * return path channel.
3166 */
3167 qemu_sem_post(&s->postcopy_pause_rp_sem);
3168
3169 /* Do the resume logic */
3170 if (postcopy_do_resume(s) == 0) {
3171 /* Let's continue! */
3172 trace_postcopy_pause_continued();
3173 return MIG_THR_ERR_RECOVERED;
3174 } else {
3175 /*
3176 * Something wrong happened during the recovery, let's
3177 * pause again. Pause is always better than throwing
3178 * data away.
3179 */
3180 continue;
3181 }
3182 } else {
3183 /* This is not right... Time to quit. */
3184 return MIG_THR_ERR_FATAL;
3185 }
3186 }
3187 }
3188
3189 static MigThrError migration_detect_error(MigrationState *s)
3190 {
3191 int ret;
3192 int state = s->state;
3193 Error *local_error = NULL;
3194
3195 if (state == MIGRATION_STATUS_CANCELLING ||
3196 state == MIGRATION_STATUS_CANCELLED) {
3197 /* End the migration, but don't set the state to failed */
3198 return MIG_THR_ERR_FATAL;
3199 }
3200
3201 /* Try to detect any file errors */
3202 ret = qemu_file_get_error_obj(s->to_dst_file, &local_error);
3203 if (!ret) {
3204 /* Everything is fine */
3205 assert(!local_error);
3206 return MIG_THR_ERR_NONE;
3207 }
3208
3209 if (local_error) {
3210 migrate_set_error(s, local_error);
3211 error_free(local_error);
3212 }
3213
3214 if (state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) {
3215 /*
3216 * For postcopy, we allow the network to be down for a
3217 * while. After that, it can be continued by a
3218 * recovery phase.
3219 */
3220 return postcopy_pause(s);
3221 } else {
3222 /*
3223 * For precopy (or postcopy with error outside IO), we fail
3224 * with no time.
3225 */
3226 migrate_set_state(&s->state, state, MIGRATION_STATUS_FAILED);
3227 trace_migration_thread_file_err();
3228
3229 /* Time to stop the migration, now. */
3230 return MIG_THR_ERR_FATAL;
3231 }
3232 }
3233
3234 /* How many bytes have we transferred since the beginning of the migration */
3235 static uint64_t migration_total_bytes(MigrationState *s)
3236 {
3237 return qemu_ftell(s->to_dst_file) + ram_counters.multifd_bytes;
3238 }
3239
3240 static void migration_calculate_complete(MigrationState *s)
3241 {
3242 uint64_t bytes = migration_total_bytes(s);
3243 int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
3244 int64_t transfer_time;
3245
3246 s->total_time = end_time - s->start_time;
3247 if (!s->downtime) {
3248 /*
3249 * It's still not set, so we are precopy migration. For
3250 * postcopy, downtime is calculated during postcopy_start().
3251 */
3252 s->downtime = end_time - s->downtime_start;
3253 }
3254
3255 transfer_time = s->total_time - s->setup_time;
3256 if (transfer_time) {
3257 s->mbps = ((double) bytes * 8.0) / transfer_time / 1000;
3258 }
3259 }
3260
3261 static void update_iteration_initial_status(MigrationState *s)
3262 {
3263 /*
3264 * Update these three fields at the same time to avoid mismatch info lead
3265 * wrong speed calculation.
3266 */
3267 s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
3268 s->iteration_initial_bytes = migration_total_bytes(s);
3269 s->iteration_initial_pages = ram_get_total_transferred_pages();
3270 }
3271
3272 static void migration_update_counters(MigrationState *s,
3273 int64_t current_time)
3274 {
3275 uint64_t transferred, transferred_pages, time_spent;
3276 uint64_t current_bytes; /* bytes transferred since the beginning */
3277 double bandwidth;
3278
3279 if (current_time < s->iteration_start_time + BUFFER_DELAY) {
3280 return;
3281 }
3282
3283 current_bytes = migration_total_bytes(s);
3284 transferred = current_bytes - s->iteration_initial_bytes;
3285 time_spent = current_time - s->iteration_start_time;
3286 bandwidth = (double)transferred / time_spent;
3287 s->threshold_size = bandwidth * s->parameters.downtime_limit;
3288
3289 s->mbps = (((double) transferred * 8.0) /
3290 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
3291
3292 transferred_pages = ram_get_total_transferred_pages() -
3293 s->iteration_initial_pages;
3294 s->pages_per_second = (double) transferred_pages /
3295 (((double) time_spent / 1000.0));
3296
3297 /*
3298 * if we haven't sent anything, we don't want to
3299 * recalculate. 10000 is a small enough number for our purposes
3300 */
3301 if (ram_counters.dirty_pages_rate && transferred > 10000) {
3302 s->expected_downtime = ram_counters.remaining / bandwidth;
3303 }
3304
3305 qemu_file_reset_rate_limit(s->to_dst_file);
3306
3307 update_iteration_initial_status(s);
3308
3309 trace_migrate_transferred(transferred, time_spent,
3310 bandwidth, s->threshold_size);
3311 }
3312
3313 /* Migration thread iteration status */
3314 typedef enum {
3315 MIG_ITERATE_RESUME, /* Resume current iteration */
3316 MIG_ITERATE_SKIP, /* Skip current iteration */
3317 MIG_ITERATE_BREAK, /* Break the loop */
3318 } MigIterateState;
3319
3320 /*
3321 * Return true if continue to the next iteration directly, false
3322 * otherwise.
3323 */
3324 static MigIterateState migration_iteration_run(MigrationState *s)
3325 {
3326 uint64_t pending_size, pend_pre, pend_compat, pend_post;
3327 bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE;
3328
3329 qemu_savevm_state_pending(s->to_dst_file, s->threshold_size, &pend_pre,
3330 &pend_compat, &pend_post);
3331 pending_size = pend_pre + pend_compat + pend_post;
3332
3333 trace_migrate_pending(pending_size, s->threshold_size,
3334 pend_pre, pend_compat, pend_post);
3335
3336 if (pending_size && pending_size >= s->threshold_size) {
3337 /* Still a significant amount to transfer */
3338 if (!in_postcopy && pend_pre <= s->threshold_size &&
3339 qatomic_read(&s->start_postcopy)) {
3340 if (postcopy_start(s)) {
3341 error_report("%s: postcopy failed to start", __func__);
3342 }
3343 return MIG_ITERATE_SKIP;
3344 }
3345 /* Just another iteration step */
3346 qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
3347 } else {
3348 trace_migration_thread_low_pending(pending_size);
3349 migration_completion(s);
3350 return MIG_ITERATE_BREAK;
3351 }
3352
3353 return MIG_ITERATE_RESUME;
3354 }
3355
3356 static void migration_iteration_finish(MigrationState *s)
3357 {
3358 /* If we enabled cpu throttling for auto-converge, turn it off. */
3359 cpu_throttle_stop();
3360
3361 qemu_mutex_lock_iothread();
3362 switch (s->state) {
3363 case MIGRATION_STATUS_COMPLETED:
3364 migration_calculate_complete(s);
3365 runstate_set(RUN_STATE_POSTMIGRATE);
3366 break;
3367
3368 case MIGRATION_STATUS_ACTIVE:
3369 /*
3370 * We should really assert here, but since it's during
3371 * migration, let's try to reduce the usage of assertions.
3372 */
3373 if (!migrate_colo_enabled()) {
3374 error_report("%s: critical error: calling COLO code without "
3375 "COLO enabled", __func__);
3376 }
3377 migrate_start_colo_process(s);
3378 /*
3379 * Fixme: we will run VM in COLO no matter its old running state.
3380 * After exited COLO, we will keep running.
3381 */
3382 s->vm_was_running = true;
3383 /* Fallthrough */
3384 case MIGRATION_STATUS_FAILED:
3385 case MIGRATION_STATUS_CANCELLED:
3386 case MIGRATION_STATUS_CANCELLING:
3387 if (s->vm_was_running) {
3388 vm_start();
3389 } else {
3390 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
3391 runstate_set(RUN_STATE_POSTMIGRATE);
3392 }
3393 }
3394 break;
3395
3396 default:
3397 /* Should not reach here, but if so, forgive the VM. */
3398 error_report("%s: Unknown ending state %d", __func__, s->state);
3399 break;
3400 }
3401 migrate_fd_cleanup_schedule(s);
3402 qemu_mutex_unlock_iothread();
3403 }
3404
3405 void migration_make_urgent_request(void)
3406 {
3407 qemu_sem_post(&migrate_get_current()->rate_limit_sem);
3408 }
3409
3410 void migration_consume_urgent_request(void)
3411 {
3412 qemu_sem_wait(&migrate_get_current()->rate_limit_sem);
3413 }
3414
3415 /* Returns true if the rate limiting was broken by an urgent request */
3416 bool migration_rate_limit(void)
3417 {
3418 int64_t now = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
3419 MigrationState *s = migrate_get_current();
3420
3421 bool urgent = false;
3422 migration_update_counters(s, now);
3423 if (qemu_file_rate_limit(s->to_dst_file)) {
3424
3425 if (qemu_file_get_error(s->to_dst_file)) {
3426 return false;
3427 }
3428 /*
3429 * Wait for a delay to do rate limiting OR
3430 * something urgent to post the semaphore.
3431 */
3432 int ms = s->iteration_start_time + BUFFER_DELAY - now;
3433 trace_migration_rate_limit_pre(ms);
3434 if (qemu_sem_timedwait(&s->rate_limit_sem, ms) == 0) {
3435 /*
3436 * We were woken by one or more urgent things but
3437 * the timedwait will have consumed one of them.
3438 * The service routine for the urgent wake will dec
3439 * the semaphore itself for each item it consumes,
3440 * so add this one we just eat back.
3441 */
3442 qemu_sem_post(&s->rate_limit_sem);
3443 urgent = true;