qdev: Introduce DEFINE_PROP_RESERVED_REGION
[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 "rdma.h"
27 #include "ram.h"
28 #include "migration/global_state.h"
29 #include "migration/misc.h"
30 #include "migration.h"
31 #include "savevm.h"
32 #include "qemu-file-channel.h"
33 #include "qemu-file.h"
34 #include "migration/vmstate.h"
35 #include "block/block.h"
36 #include "qapi/error.h"
37 #include "qapi/clone-visitor.h"
38 #include "qapi/qapi-visit-sockets.h"
39 #include "qapi/qapi-commands-migration.h"
40 #include "qapi/qapi-events-migration.h"
41 #include "qapi/qmp/qerror.h"
42 #include "qapi/qmp/qnull.h"
43 #include "qemu/rcu.h"
44 #include "block.h"
45 #include "postcopy-ram.h"
46 #include "qemu/thread.h"
47 #include "trace.h"
48 #include "exec/target_page.h"
49 #include "io/channel-buffer.h"
50 #include "migration/colo.h"
51 #include "hw/boards.h"
52 #include "hw/qdev-properties.h"
53 #include "monitor/monitor.h"
54 #include "net/announce.h"
55 #include "qemu/queue.h"
56 #include "multifd.h"
57
58 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
59
60 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
61 * data. */
62 #define BUFFER_DELAY 100
63 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
64
65 /* Time in milliseconds we are allowed to stop the source,
66 * for sending the last part */
67 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
68
69 /* Maximum migrate downtime set to 2000 seconds */
70 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000
71 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000)
72
73 /* Default compression thread count */
74 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
75 /* Default decompression thread count, usually decompression is at
76 * least 4 times as fast as compression.*/
77 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
78 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
79 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
80 /* Define default autoconverge cpu throttle migration parameters */
81 #define DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD 50
82 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
83 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
84 #define DEFAULT_MIGRATE_MAX_CPU_THROTTLE 99
85
86 /* Migration XBZRLE default cache size */
87 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024)
88
89 /* The delay time (in ms) between two COLO checkpoints */
90 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100)
91 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
92 #define DEFAULT_MIGRATE_MULTIFD_COMPRESSION MULTIFD_COMPRESSION_NONE
93 /* 0: means nocompress, 1: best speed, ... 9: best compress ratio */
94 #define DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL 1
95 /* 0: means nocompress, 1: best speed, ... 20: best compress ratio */
96 #define DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL 1
97
98 /* Background transfer rate for postcopy, 0 means unlimited, note
99 * that page requests can still exceed this limit.
100 */
101 #define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0
102
103 /*
104 * Parameters for self_announce_delay giving a stream of RARP/ARP
105 * packets after migration.
106 */
107 #define DEFAULT_MIGRATE_ANNOUNCE_INITIAL 50
108 #define DEFAULT_MIGRATE_ANNOUNCE_MAX 550
109 #define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS 5
110 #define DEFAULT_MIGRATE_ANNOUNCE_STEP 100
111
112 static NotifierList migration_state_notifiers =
113 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
114
115 static bool deferred_incoming;
116
117 /* Messages sent on the return path from destination to source */
118 enum mig_rp_message_type {
119 MIG_RP_MSG_INVALID = 0, /* Must be 0 */
120 MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */
121 MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */
122
123 MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
124 MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */
125 MIG_RP_MSG_RECV_BITMAP, /* send recved_bitmap back to source */
126 MIG_RP_MSG_RESUME_ACK, /* tell source that we are ready to resume */
127
128 MIG_RP_MSG_MAX
129 };
130
131 /* When we add fault tolerance, we could have several
132 migrations at once. For now we don't need to add
133 dynamic creation of migration */
134
135 static MigrationState *current_migration;
136 static MigrationIncomingState *current_incoming;
137
138 static bool migration_object_check(MigrationState *ms, Error **errp);
139 static int migration_maybe_pause(MigrationState *s,
140 int *current_active_state,
141 int new_state);
142 static void migrate_fd_cancel(MigrationState *s);
143
144 void migration_object_init(void)
145 {
146 MachineState *ms = MACHINE(qdev_get_machine());
147 Error *err = NULL;
148
149 /* This can only be called once. */
150 assert(!current_migration);
151 current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
152
153 /*
154 * Init the migrate incoming object as well no matter whether
155 * we'll use it or not.
156 */
157 assert(!current_incoming);
158 current_incoming = g_new0(MigrationIncomingState, 1);
159 current_incoming->state = MIGRATION_STATUS_NONE;
160 current_incoming->postcopy_remote_fds =
161 g_array_new(FALSE, TRUE, sizeof(struct PostCopyFD));
162 qemu_mutex_init(&current_incoming->rp_mutex);
163 qemu_event_init(&current_incoming->main_thread_load_event, false);
164 qemu_sem_init(&current_incoming->postcopy_pause_sem_dst, 0);
165 qemu_sem_init(&current_incoming->postcopy_pause_sem_fault, 0);
166
167 init_dirty_bitmap_incoming_migration();
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 /* For outgoing */
195 MigrationState *migrate_get_current(void)
196 {
197 /* This can only be called after the object created. */
198 assert(current_migration);
199 return current_migration;
200 }
201
202 MigrationIncomingState *migration_incoming_get_current(void)
203 {
204 assert(current_incoming);
205 return current_incoming;
206 }
207
208 void migration_incoming_state_destroy(void)
209 {
210 struct MigrationIncomingState *mis = migration_incoming_get_current();
211
212 if (mis->to_src_file) {
213 /* Tell source that we are done */
214 migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
215 qemu_fclose(mis->to_src_file);
216 mis->to_src_file = NULL;
217 }
218
219 if (mis->from_src_file) {
220 qemu_fclose(mis->from_src_file);
221 mis->from_src_file = NULL;
222 }
223 if (mis->postcopy_remote_fds) {
224 g_array_free(mis->postcopy_remote_fds, TRUE);
225 mis->postcopy_remote_fds = NULL;
226 }
227
228 qemu_event_reset(&mis->main_thread_load_event);
229
230 if (mis->socket_address_list) {
231 qapi_free_SocketAddressList(mis->socket_address_list);
232 mis->socket_address_list = NULL;
233 }
234 }
235
236 static void migrate_generate_event(int new_state)
237 {
238 if (migrate_use_events()) {
239 qapi_event_send_migration(new_state);
240 }
241 }
242
243 static bool migrate_late_block_activate(void)
244 {
245 MigrationState *s;
246
247 s = migrate_get_current();
248
249 return s->enabled_capabilities[
250 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE];
251 }
252
253 /*
254 * Called on -incoming with a defer: uri.
255 * The migration can be started later after any parameters have been
256 * changed.
257 */
258 static void deferred_incoming_migration(Error **errp)
259 {
260 if (deferred_incoming) {
261 error_setg(errp, "Incoming migration already deferred");
262 }
263 deferred_incoming = true;
264 }
265
266 /*
267 * Send a message on the return channel back to the source
268 * of the migration.
269 */
270 static int migrate_send_rp_message(MigrationIncomingState *mis,
271 enum mig_rp_message_type message_type,
272 uint16_t len, void *data)
273 {
274 int ret = 0;
275
276 trace_migrate_send_rp_message((int)message_type, len);
277 qemu_mutex_lock(&mis->rp_mutex);
278
279 /*
280 * It's possible that the file handle got lost due to network
281 * failures.
282 */
283 if (!mis->to_src_file) {
284 ret = -EIO;
285 goto error;
286 }
287
288 qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
289 qemu_put_be16(mis->to_src_file, len);
290 qemu_put_buffer(mis->to_src_file, data, len);
291 qemu_fflush(mis->to_src_file);
292
293 /* It's possible that qemu file got error during sending */
294 ret = qemu_file_get_error(mis->to_src_file);
295
296 error:
297 qemu_mutex_unlock(&mis->rp_mutex);
298 return ret;
299 }
300
301 /* Request a range of pages from the source VM at the given
302 * start address.
303 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
304 * as the last request (a name must have been given previously)
305 * Start: Address offset within the RB
306 * Len: Length in bytes required - must be a multiple of pagesize
307 */
308 int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
309 ram_addr_t start, size_t len)
310 {
311 uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
312 size_t msglen = 12; /* start + len */
313 enum mig_rp_message_type msg_type;
314
315 *(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
316 *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
317
318 if (rbname) {
319 int rbname_len = strlen(rbname);
320 assert(rbname_len < 256);
321
322 bufc[msglen++] = rbname_len;
323 memcpy(bufc + msglen, rbname, rbname_len);
324 msglen += rbname_len;
325 msg_type = MIG_RP_MSG_REQ_PAGES_ID;
326 } else {
327 msg_type = MIG_RP_MSG_REQ_PAGES;
328 }
329
330 return migrate_send_rp_message(mis, msg_type, msglen, bufc);
331 }
332
333 static bool migration_colo_enabled;
334 bool migration_incoming_colo_enabled(void)
335 {
336 return migration_colo_enabled;
337 }
338
339 void migration_incoming_disable_colo(void)
340 {
341 migration_colo_enabled = false;
342 }
343
344 void migration_incoming_enable_colo(void)
345 {
346 migration_colo_enabled = true;
347 }
348
349 void migrate_add_address(SocketAddress *address)
350 {
351 MigrationIncomingState *mis = migration_incoming_get_current();
352 SocketAddressList *addrs;
353
354 addrs = g_new0(SocketAddressList, 1);
355 addrs->next = mis->socket_address_list;
356 mis->socket_address_list = addrs;
357 addrs->value = QAPI_CLONE(SocketAddress, address);
358 }
359
360 void qemu_start_incoming_migration(const char *uri, Error **errp)
361 {
362 const char *p;
363
364 qapi_event_send_migration(MIGRATION_STATUS_SETUP);
365 if (!strcmp(uri, "defer")) {
366 deferred_incoming_migration(errp);
367 } else if (strstart(uri, "tcp:", &p)) {
368 tcp_start_incoming_migration(p, errp);
369 #ifdef CONFIG_RDMA
370 } else if (strstart(uri, "rdma:", &p)) {
371 rdma_start_incoming_migration(p, errp);
372 #endif
373 } else if (strstart(uri, "exec:", &p)) {
374 exec_start_incoming_migration(p, errp);
375 } else if (strstart(uri, "unix:", &p)) {
376 unix_start_incoming_migration(p, errp);
377 } else if (strstart(uri, "fd:", &p)) {
378 fd_start_incoming_migration(p, errp);
379 } else {
380 error_setg(errp, "unknown migration protocol: %s", uri);
381 }
382 }
383
384 static void process_incoming_migration_bh(void *opaque)
385 {
386 Error *local_err = NULL;
387 MigrationIncomingState *mis = opaque;
388
389 /* If capability late_block_activate is set:
390 * Only fire up the block code now if we're going to restart the
391 * VM, else 'cont' will do it.
392 * This causes file locking to happen; so we don't want it to happen
393 * unless we really are starting the VM.
394 */
395 if (!migrate_late_block_activate() ||
396 (autostart && (!global_state_received() ||
397 global_state_get_runstate() == RUN_STATE_RUNNING))) {
398 /* Make sure all file formats flush their mutable metadata.
399 * If we get an error here, just don't restart the VM yet. */
400 bdrv_invalidate_cache_all(&local_err);
401 if (local_err) {
402 error_report_err(local_err);
403 local_err = NULL;
404 autostart = false;
405 }
406 }
407
408 /*
409 * This must happen after all error conditions are dealt with and
410 * we're sure the VM is going to be running on this host.
411 */
412 qemu_announce_self(&mis->announce_timer, migrate_announce_params());
413
414 if (multifd_load_cleanup(&local_err) != 0) {
415 error_report_err(local_err);
416 autostart = false;
417 }
418 /* If global state section was not received or we are in running
419 state, we need to obey autostart. Any other state is set with
420 runstate_set. */
421
422 dirty_bitmap_mig_before_vm_start();
423
424 if (!global_state_received() ||
425 global_state_get_runstate() == RUN_STATE_RUNNING) {
426 if (autostart) {
427 vm_start();
428 } else {
429 runstate_set(RUN_STATE_PAUSED);
430 }
431 } else if (migration_incoming_colo_enabled()) {
432 migration_incoming_disable_colo();
433 vm_start();
434 } else {
435 runstate_set(global_state_get_runstate());
436 }
437 /*
438 * This must happen after any state changes since as soon as an external
439 * observer sees this event they might start to prod at the VM assuming
440 * it's ready to use.
441 */
442 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
443 MIGRATION_STATUS_COMPLETED);
444 qemu_bh_delete(mis->bh);
445 migration_incoming_state_destroy();
446 }
447
448 static void process_incoming_migration_co(void *opaque)
449 {
450 MigrationIncomingState *mis = migration_incoming_get_current();
451 PostcopyState ps;
452 int ret;
453 Error *local_err = NULL;
454
455 assert(mis->from_src_file);
456 mis->migration_incoming_co = qemu_coroutine_self();
457 mis->largest_page_size = qemu_ram_pagesize_largest();
458 postcopy_state_set(POSTCOPY_INCOMING_NONE);
459 migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
460 MIGRATION_STATUS_ACTIVE);
461 ret = qemu_loadvm_state(mis->from_src_file);
462
463 ps = postcopy_state_get();
464 trace_process_incoming_migration_co_end(ret, ps);
465 if (ps != POSTCOPY_INCOMING_NONE) {
466 if (ps == POSTCOPY_INCOMING_ADVISE) {
467 /*
468 * Where a migration had postcopy enabled (and thus went to advise)
469 * but managed to complete within the precopy period, we can use
470 * the normal exit.
471 */
472 postcopy_ram_incoming_cleanup(mis);
473 } else if (ret >= 0) {
474 /*
475 * Postcopy was started, cleanup should happen at the end of the
476 * postcopy thread.
477 */
478 trace_process_incoming_migration_co_postcopy_end_main();
479 return;
480 }
481 /* Else if something went wrong then just fall out of the normal exit */
482 }
483
484 /* we get COLO info, and know if we are in COLO mode */
485 if (!ret && migration_incoming_colo_enabled()) {
486 /* Make sure all file formats flush their mutable metadata */
487 bdrv_invalidate_cache_all(&local_err);
488 if (local_err) {
489 error_report_err(local_err);
490 goto fail;
491 }
492
493 qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming",
494 colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
495 mis->have_colo_incoming_thread = true;
496 qemu_coroutine_yield();
497
498 /* Wait checkpoint incoming thread exit before free resource */
499 qemu_thread_join(&mis->colo_incoming_thread);
500 /* We hold the global iothread lock, so it is safe here */
501 colo_release_ram_cache();
502 }
503
504 if (ret < 0) {
505 error_report("load of migration failed: %s", strerror(-ret));
506 goto fail;
507 }
508 mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
509 qemu_bh_schedule(mis->bh);
510 mis->migration_incoming_co = NULL;
511 return;
512 fail:
513 local_err = NULL;
514 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
515 MIGRATION_STATUS_FAILED);
516 qemu_fclose(mis->from_src_file);
517 if (multifd_load_cleanup(&local_err) != 0) {
518 error_report_err(local_err);
519 }
520 exit(EXIT_FAILURE);
521 }
522
523 /**
524 * @migration_incoming_setup: Setup incoming migration
525 *
526 * Returns 0 for no error or 1 for error
527 *
528 * @f: file for main migration channel
529 * @errp: where to put errors
530 */
531 static int migration_incoming_setup(QEMUFile *f, Error **errp)
532 {
533 MigrationIncomingState *mis = migration_incoming_get_current();
534 Error *local_err = NULL;
535
536 if (multifd_load_setup(&local_err) != 0) {
537 /* We haven't been able to create multifd threads
538 nothing better to do */
539 error_report_err(local_err);
540 exit(EXIT_FAILURE);
541 }
542
543 if (!mis->from_src_file) {
544 mis->from_src_file = f;
545 }
546 qemu_file_set_blocking(f, false);
547 return 0;
548 }
549
550 void migration_incoming_process(void)
551 {
552 Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
553 qemu_coroutine_enter(co);
554 }
555
556 /* Returns true if recovered from a paused migration, otherwise false */
557 static bool postcopy_try_recover(QEMUFile *f)
558 {
559 MigrationIncomingState *mis = migration_incoming_get_current();
560
561 if (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
562 /* Resumed from a paused postcopy migration */
563
564 mis->from_src_file = f;
565 /* Postcopy has standalone thread to do vm load */
566 qemu_file_set_blocking(f, true);
567
568 /* Re-configure the return path */
569 mis->to_src_file = qemu_file_get_return_path(f);
570
571 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_PAUSED,
572 MIGRATION_STATUS_POSTCOPY_RECOVER);
573
574 /*
575 * Here, we only wake up the main loading thread (while the
576 * fault thread will still be waiting), so that we can receive
577 * commands from source now, and answer it if needed. The
578 * fault thread will be woken up afterwards until we are sure
579 * that source is ready to reply to page requests.
580 */
581 qemu_sem_post(&mis->postcopy_pause_sem_dst);
582 return true;
583 }
584
585 return false;
586 }
587
588 void migration_fd_process_incoming(QEMUFile *f, Error **errp)
589 {
590 Error *local_err = NULL;
591
592 if (postcopy_try_recover(f)) {
593 return;
594 }
595
596 if (migration_incoming_setup(f, &local_err)) {
597 if (local_err) {
598 error_propagate(errp, local_err);
599 }
600 return;
601 }
602 migration_incoming_process();
603 }
604
605 void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp)
606 {
607 MigrationIncomingState *mis = migration_incoming_get_current();
608 Error *local_err = NULL;
609 bool start_migration;
610
611 if (!mis->from_src_file) {
612 /* The first connection (multifd may have multiple) */
613 QEMUFile *f = qemu_fopen_channel_input(ioc);
614
615 /* If it's a recovery, we're done */
616 if (postcopy_try_recover(f)) {
617 return;
618 }
619
620 if (migration_incoming_setup(f, &local_err)) {
621 if (local_err) {
622 error_propagate(errp, local_err);
623 }
624 return;
625 }
626
627 /*
628 * Common migration only needs one channel, so we can start
629 * right now. Multifd needs more than one channel, we wait.
630 */
631 start_migration = !migrate_use_multifd();
632 } else {
633 /* Multiple connections */
634 assert(migrate_use_multifd());
635 start_migration = multifd_recv_new_channel(ioc, &local_err);
636 if (local_err) {
637 error_propagate(errp, local_err);
638 return;
639 }
640 }
641
642 if (start_migration) {
643 migration_incoming_process();
644 }
645 }
646
647 /**
648 * @migration_has_all_channels: We have received all channels that we need
649 *
650 * Returns true when we have got connections to all the channels that
651 * we need for migration.
652 */
653 bool migration_has_all_channels(void)
654 {
655 MigrationIncomingState *mis = migration_incoming_get_current();
656 bool all_channels;
657
658 all_channels = multifd_recv_all_channels_created();
659
660 return all_channels && mis->from_src_file != NULL;
661 }
662
663 /*
664 * Send a 'SHUT' message on the return channel with the given value
665 * to indicate that we've finished with the RP. Non-0 value indicates
666 * error.
667 */
668 void migrate_send_rp_shut(MigrationIncomingState *mis,
669 uint32_t value)
670 {
671 uint32_t buf;
672
673 buf = cpu_to_be32(value);
674 migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
675 }
676
677 /*
678 * Send a 'PONG' message on the return channel with the given value
679 * (normally in response to a 'PING')
680 */
681 void migrate_send_rp_pong(MigrationIncomingState *mis,
682 uint32_t value)
683 {
684 uint32_t buf;
685
686 buf = cpu_to_be32(value);
687 migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
688 }
689
690 void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
691 char *block_name)
692 {
693 char buf[512];
694 int len;
695 int64_t res;
696
697 /*
698 * First, we send the header part. It contains only the len of
699 * idstr, and the idstr itself.
700 */
701 len = strlen(block_name);
702 buf[0] = len;
703 memcpy(buf + 1, block_name, len);
704
705 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
706 error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
707 __func__);
708 return;
709 }
710
711 migrate_send_rp_message(mis, MIG_RP_MSG_RECV_BITMAP, len + 1, buf);
712
713 /*
714 * Next, we dump the received bitmap to the stream.
715 *
716 * TODO: currently we are safe since we are the only one that is
717 * using the to_src_file handle (fault thread is still paused),
718 * and it's ok even not taking the mutex. However the best way is
719 * to take the lock before sending the message header, and release
720 * the lock after sending the bitmap.
721 */
722 qemu_mutex_lock(&mis->rp_mutex);
723 res = ramblock_recv_bitmap_send(mis->to_src_file, block_name);
724 qemu_mutex_unlock(&mis->rp_mutex);
725
726 trace_migrate_send_rp_recv_bitmap(block_name, res);
727 }
728
729 void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value)
730 {
731 uint32_t buf;
732
733 buf = cpu_to_be32(value);
734 migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf);
735 }
736
737 MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
738 {
739 MigrationCapabilityStatusList *head = NULL;
740 MigrationCapabilityStatusList *caps;
741 MigrationState *s = migrate_get_current();
742 int i;
743
744 caps = NULL; /* silence compiler warning */
745 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
746 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
747 if (i == MIGRATION_CAPABILITY_BLOCK) {
748 continue;
749 }
750 #endif
751 if (head == NULL) {
752 head = g_malloc0(sizeof(*caps));
753 caps = head;
754 } else {
755 caps->next = g_malloc0(sizeof(*caps));
756 caps = caps->next;
757 }
758 caps->value =
759 g_malloc(sizeof(*caps->value));
760 caps->value->capability = i;
761 caps->value->state = s->enabled_capabilities[i];
762 }
763
764 return head;
765 }
766
767 MigrationParameters *qmp_query_migrate_parameters(Error **errp)
768 {
769 MigrationParameters *params;
770 MigrationState *s = migrate_get_current();
771
772 /* TODO use QAPI_CLONE() instead of duplicating it inline */
773 params = g_malloc0(sizeof(*params));
774 params->has_compress_level = true;
775 params->compress_level = s->parameters.compress_level;
776 params->has_compress_threads = true;
777 params->compress_threads = s->parameters.compress_threads;
778 params->has_compress_wait_thread = true;
779 params->compress_wait_thread = s->parameters.compress_wait_thread;
780 params->has_decompress_threads = true;
781 params->decompress_threads = s->parameters.decompress_threads;
782 params->has_throttle_trigger_threshold = true;
783 params->throttle_trigger_threshold = s->parameters.throttle_trigger_threshold;
784 params->has_cpu_throttle_initial = true;
785 params->cpu_throttle_initial = s->parameters.cpu_throttle_initial;
786 params->has_cpu_throttle_increment = true;
787 params->cpu_throttle_increment = s->parameters.cpu_throttle_increment;
788 params->has_cpu_throttle_tailslow = true;
789 params->cpu_throttle_tailslow = s->parameters.cpu_throttle_tailslow;
790 params->has_tls_creds = true;
791 params->tls_creds = g_strdup(s->parameters.tls_creds);
792 params->has_tls_hostname = true;
793 params->tls_hostname = g_strdup(s->parameters.tls_hostname);
794 params->has_tls_authz = true;
795 params->tls_authz = g_strdup(s->parameters.tls_authz ?
796 s->parameters.tls_authz : "");
797 params->has_max_bandwidth = true;
798 params->max_bandwidth = s->parameters.max_bandwidth;
799 params->has_downtime_limit = true;
800 params->downtime_limit = s->parameters.downtime_limit;
801 params->has_x_checkpoint_delay = true;
802 params->x_checkpoint_delay = s->parameters.x_checkpoint_delay;
803 params->has_block_incremental = true;
804 params->block_incremental = s->parameters.block_incremental;
805 params->has_multifd_channels = true;
806 params->multifd_channels = s->parameters.multifd_channels;
807 params->has_multifd_compression = true;
808 params->multifd_compression = s->parameters.multifd_compression;
809 params->has_multifd_zlib_level = true;
810 params->multifd_zlib_level = s->parameters.multifd_zlib_level;
811 params->has_multifd_zstd_level = true;
812 params->multifd_zstd_level = s->parameters.multifd_zstd_level;
813 params->has_xbzrle_cache_size = true;
814 params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
815 params->has_max_postcopy_bandwidth = true;
816 params->max_postcopy_bandwidth = s->parameters.max_postcopy_bandwidth;
817 params->has_max_cpu_throttle = true;
818 params->max_cpu_throttle = s->parameters.max_cpu_throttle;
819 params->has_announce_initial = true;
820 params->announce_initial = s->parameters.announce_initial;
821 params->has_announce_max = true;
822 params->announce_max = s->parameters.announce_max;
823 params->has_announce_rounds = true;
824 params->announce_rounds = s->parameters.announce_rounds;
825 params->has_announce_step = true;
826 params->announce_step = s->parameters.announce_step;
827
828 return params;
829 }
830
831 AnnounceParameters *migrate_announce_params(void)
832 {
833 static AnnounceParameters ap;
834
835 MigrationState *s = migrate_get_current();
836
837 ap.initial = s->parameters.announce_initial;
838 ap.max = s->parameters.announce_max;
839 ap.rounds = s->parameters.announce_rounds;
840 ap.step = s->parameters.announce_step;
841
842 return &ap;
843 }
844
845 /*
846 * Return true if we're already in the middle of a migration
847 * (i.e. any of the active or setup states)
848 */
849 bool migration_is_setup_or_active(int state)
850 {
851 switch (state) {
852 case MIGRATION_STATUS_ACTIVE:
853 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
854 case MIGRATION_STATUS_POSTCOPY_PAUSED:
855 case MIGRATION_STATUS_POSTCOPY_RECOVER:
856 case MIGRATION_STATUS_SETUP:
857 case MIGRATION_STATUS_PRE_SWITCHOVER:
858 case MIGRATION_STATUS_DEVICE:
859 case MIGRATION_STATUS_WAIT_UNPLUG:
860 case MIGRATION_STATUS_COLO:
861 return true;
862
863 default:
864 return false;
865
866 }
867 }
868
869 bool migration_is_running(int state)
870 {
871 switch (state) {
872 case MIGRATION_STATUS_ACTIVE:
873 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
874 case MIGRATION_STATUS_POSTCOPY_PAUSED:
875 case MIGRATION_STATUS_POSTCOPY_RECOVER:
876 case MIGRATION_STATUS_SETUP:
877 case MIGRATION_STATUS_PRE_SWITCHOVER:
878 case MIGRATION_STATUS_DEVICE:
879 case MIGRATION_STATUS_WAIT_UNPLUG:
880 case MIGRATION_STATUS_CANCELLING:
881 return true;
882
883 default:
884 return false;
885
886 }
887 }
888
889 static void populate_time_info(MigrationInfo *info, MigrationState *s)
890 {
891 info->has_status = true;
892 info->has_setup_time = true;
893 info->setup_time = s->setup_time;
894 if (s->state == MIGRATION_STATUS_COMPLETED) {
895 info->has_total_time = true;
896 info->total_time = s->total_time;
897 info->has_downtime = true;
898 info->downtime = s->downtime;
899 } else {
900 info->has_total_time = true;
901 info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) -
902 s->start_time;
903 info->has_expected_downtime = true;
904 info->expected_downtime = s->expected_downtime;
905 }
906 }
907
908 static void populate_ram_info(MigrationInfo *info, MigrationState *s)
909 {
910 info->has_ram = true;
911 info->ram = g_malloc0(sizeof(*info->ram));
912 info->ram->transferred = ram_counters.transferred;
913 info->ram->total = ram_bytes_total();
914 info->ram->duplicate = ram_counters.duplicate;
915 /* legacy value. It is not used anymore */
916 info->ram->skipped = 0;
917 info->ram->normal = ram_counters.normal;
918 info->ram->normal_bytes = ram_counters.normal *
919 qemu_target_page_size();
920 info->ram->mbps = s->mbps;
921 info->ram->dirty_sync_count = ram_counters.dirty_sync_count;
922 info->ram->postcopy_requests = ram_counters.postcopy_requests;
923 info->ram->page_size = qemu_target_page_size();
924 info->ram->multifd_bytes = ram_counters.multifd_bytes;
925 info->ram->pages_per_second = s->pages_per_second;
926
927 if (migrate_use_xbzrle()) {
928 info->has_xbzrle_cache = true;
929 info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
930 info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
931 info->xbzrle_cache->bytes = xbzrle_counters.bytes;
932 info->xbzrle_cache->pages = xbzrle_counters.pages;
933 info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss;
934 info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate;
935 info->xbzrle_cache->encoding_rate = xbzrle_counters.encoding_rate;
936 info->xbzrle_cache->overflow = xbzrle_counters.overflow;
937 }
938
939 if (migrate_use_compression()) {
940 info->has_compression = true;
941 info->compression = g_malloc0(sizeof(*info->compression));
942 info->compression->pages = compression_counters.pages;
943 info->compression->busy = compression_counters.busy;
944 info->compression->busy_rate = compression_counters.busy_rate;
945 info->compression->compressed_size =
946 compression_counters.compressed_size;
947 info->compression->compression_rate =
948 compression_counters.compression_rate;
949 }
950
951 if (cpu_throttle_active()) {
952 info->has_cpu_throttle_percentage = true;
953 info->cpu_throttle_percentage = cpu_throttle_get_percentage();
954 }
955
956 if (s->state != MIGRATION_STATUS_COMPLETED) {
957 info->ram->remaining = ram_bytes_remaining();
958 info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate;
959 }
960 }
961
962 static void populate_disk_info(MigrationInfo *info)
963 {
964 if (blk_mig_active()) {
965 info->has_disk = true;
966 info->disk = g_malloc0(sizeof(*info->disk));
967 info->disk->transferred = blk_mig_bytes_transferred();
968 info->disk->remaining = blk_mig_bytes_remaining();
969 info->disk->total = blk_mig_bytes_total();
970 }
971 }
972
973 static void fill_source_migration_info(MigrationInfo *info)
974 {
975 MigrationState *s = migrate_get_current();
976
977 switch (s->state) {
978 case MIGRATION_STATUS_NONE:
979 /* no migration has happened ever */
980 /* do not overwrite destination migration status */
981 return;
982 break;
983 case MIGRATION_STATUS_SETUP:
984 info->has_status = true;
985 info->has_total_time = false;
986 break;
987 case MIGRATION_STATUS_ACTIVE:
988 case MIGRATION_STATUS_CANCELLING:
989 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
990 case MIGRATION_STATUS_PRE_SWITCHOVER:
991 case MIGRATION_STATUS_DEVICE:
992 case MIGRATION_STATUS_POSTCOPY_PAUSED:
993 case MIGRATION_STATUS_POSTCOPY_RECOVER:
994 /* TODO add some postcopy stats */
995 populate_time_info(info, s);
996 populate_ram_info(info, s);
997 populate_disk_info(info);
998 break;
999 case MIGRATION_STATUS_COLO:
1000 info->has_status = true;
1001 /* TODO: display COLO specific information (checkpoint info etc.) */
1002 break;
1003 case MIGRATION_STATUS_COMPLETED:
1004 populate_time_info(info, s);
1005 populate_ram_info(info, s);
1006 break;
1007 case MIGRATION_STATUS_FAILED:
1008 info->has_status = true;
1009 if (s->error) {
1010 info->has_error_desc = true;
1011 info->error_desc = g_strdup(error_get_pretty(s->error));
1012 }
1013 break;
1014 case MIGRATION_STATUS_CANCELLED:
1015 info->has_status = true;
1016 break;
1017 case MIGRATION_STATUS_WAIT_UNPLUG:
1018 info->has_status = true;
1019 break;
1020 }
1021 info->status = s->state;
1022 }
1023
1024 /**
1025 * @migration_caps_check - check capability validity
1026 *
1027 * @cap_list: old capability list, array of bool
1028 * @params: new capabilities to be applied soon
1029 * @errp: set *errp if the check failed, with reason
1030 *
1031 * Returns true if check passed, otherwise false.
1032 */
1033 static bool migrate_caps_check(bool *cap_list,
1034 MigrationCapabilityStatusList *params,
1035 Error **errp)
1036 {
1037 MigrationCapabilityStatusList *cap;
1038 bool old_postcopy_cap;
1039 MigrationIncomingState *mis = migration_incoming_get_current();
1040
1041 old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM];
1042
1043 for (cap = params; cap; cap = cap->next) {
1044 cap_list[cap->value->capability] = cap->value->state;
1045 }
1046
1047 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
1048 if (cap_list[MIGRATION_CAPABILITY_BLOCK]) {
1049 error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) "
1050 "block migration");
1051 error_append_hint(errp, "Use drive_mirror+NBD instead.\n");
1052 return false;
1053 }
1054 #endif
1055
1056 #ifndef CONFIG_REPLICATION
1057 if (cap_list[MIGRATION_CAPABILITY_X_COLO]) {
1058 error_setg(errp, "QEMU compiled without replication module"
1059 " can't enable COLO");
1060 error_append_hint(errp, "Please enable replication before COLO.\n");
1061 return false;
1062 }
1063 #endif
1064
1065 if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) {
1066 /* This check is reasonably expensive, so only when it's being
1067 * set the first time, also it's only the destination that needs
1068 * special support.
1069 */
1070 if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) &&
1071 !postcopy_ram_supported_by_host(mis)) {
1072 /* postcopy_ram_supported_by_host will have emitted a more
1073 * detailed message
1074 */
1075 error_setg(errp, "Postcopy is not supported");
1076 return false;
1077 }
1078
1079 if (cap_list[MIGRATION_CAPABILITY_X_IGNORE_SHARED]) {
1080 error_setg(errp, "Postcopy is not compatible with ignore-shared");
1081 return false;
1082 }
1083 }
1084
1085 return true;
1086 }
1087
1088 static void fill_destination_migration_info(MigrationInfo *info)
1089 {
1090 MigrationIncomingState *mis = migration_incoming_get_current();
1091
1092 if (mis->socket_address_list) {
1093 info->has_socket_address = true;
1094 info->socket_address =
1095 QAPI_CLONE(SocketAddressList, mis->socket_address_list);
1096 }
1097
1098 switch (mis->state) {
1099 case MIGRATION_STATUS_NONE:
1100 return;
1101 break;
1102 case MIGRATION_STATUS_SETUP:
1103 case MIGRATION_STATUS_CANCELLING:
1104 case MIGRATION_STATUS_CANCELLED:
1105 case MIGRATION_STATUS_ACTIVE:
1106 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1107 case MIGRATION_STATUS_POSTCOPY_PAUSED:
1108 case MIGRATION_STATUS_POSTCOPY_RECOVER:
1109 case MIGRATION_STATUS_FAILED:
1110 case MIGRATION_STATUS_COLO:
1111 info->has_status = true;
1112 break;
1113 case MIGRATION_STATUS_COMPLETED:
1114 info->has_status = true;
1115 fill_destination_postcopy_migration_info(info);
1116 break;
1117 }
1118 info->status = mis->state;
1119 }
1120
1121 MigrationInfo *qmp_query_migrate(Error **errp)
1122 {
1123 MigrationInfo *info = g_malloc0(sizeof(*info));
1124
1125 fill_destination_migration_info(info);
1126 fill_source_migration_info(info);
1127
1128 return info;
1129 }
1130
1131 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
1132 Error **errp)
1133 {
1134 MigrationState *s = migrate_get_current();
1135 MigrationCapabilityStatusList *cap;
1136 bool cap_list[MIGRATION_CAPABILITY__MAX];
1137
1138 if (migration_is_running(s->state)) {
1139 error_setg(errp, QERR_MIGRATION_ACTIVE);
1140 return;
1141 }
1142
1143 memcpy(cap_list, s->enabled_capabilities, sizeof(cap_list));
1144 if (!migrate_caps_check(cap_list, params, errp)) {
1145 return;
1146 }
1147
1148 for (cap = params; cap; cap = cap->next) {
1149 s->enabled_capabilities[cap->value->capability] = cap->value->state;
1150 }
1151 }
1152
1153 /*
1154 * Check whether the parameters are valid. Error will be put into errp
1155 * (if provided). Return true if valid, otherwise false.
1156 */
1157 static bool migrate_params_check(MigrationParameters *params, Error **errp)
1158 {
1159 if (params->has_compress_level &&
1160 (params->compress_level > 9)) {
1161 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
1162 "is invalid, it should be in the range of 0 to 9");
1163 return false;
1164 }
1165
1166 if (params->has_compress_threads && (params->compress_threads < 1)) {
1167 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1168 "compress_threads",
1169 "is invalid, it should be in the range of 1 to 255");
1170 return false;
1171 }
1172
1173 if (params->has_decompress_threads && (params->decompress_threads < 1)) {
1174 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1175 "decompress_threads",
1176 "is invalid, it should be in the range of 1 to 255");
1177 return false;
1178 }
1179
1180 if (params->has_throttle_trigger_threshold &&
1181 (params->throttle_trigger_threshold < 1 ||
1182 params->throttle_trigger_threshold > 100)) {
1183 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1184 "throttle_trigger_threshold",
1185 "an integer in the range of 1 to 100");
1186 return false;
1187 }
1188
1189 if (params->has_cpu_throttle_initial &&
1190 (params->cpu_throttle_initial < 1 ||
1191 params->cpu_throttle_initial > 99)) {
1192 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1193 "cpu_throttle_initial",
1194 "an integer in the range of 1 to 99");
1195 return false;
1196 }
1197
1198 if (params->has_cpu_throttle_increment &&
1199 (params->cpu_throttle_increment < 1 ||
1200 params->cpu_throttle_increment > 99)) {
1201 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1202 "cpu_throttle_increment",
1203 "an integer in the range of 1 to 99");
1204 return false;
1205 }
1206
1207 if (params->has_max_bandwidth && (params->max_bandwidth > SIZE_MAX)) {
1208 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1209 "max_bandwidth",
1210 "an integer in the range of 0 to "stringify(SIZE_MAX)
1211 " bytes/second");
1212 return false;
1213 }
1214
1215 if (params->has_downtime_limit &&
1216 (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) {
1217 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1218 "downtime_limit",
1219 "an integer in the range of 0 to "
1220 stringify(MAX_MIGRATE_DOWNTIME)" ms");
1221 return false;
1222 }
1223
1224 /* x_checkpoint_delay is now always positive */
1225
1226 if (params->has_multifd_channels && (params->multifd_channels < 1)) {
1227 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1228 "multifd_channels",
1229 "is invalid, it should be in the range of 1 to 255");
1230 return false;
1231 }
1232
1233 if (params->has_multifd_zlib_level &&
1234 (params->multifd_zlib_level > 9)) {
1235 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zlib_level",
1236 "is invalid, it should be in the range of 0 to 9");
1237 return false;
1238 }
1239
1240 if (params->has_multifd_zstd_level &&
1241 (params->multifd_zstd_level > 20)) {
1242 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zstd_level",
1243 "is invalid, it should be in the range of 0 to 20");
1244 return false;
1245 }
1246
1247 if (params->has_xbzrle_cache_size &&
1248 (params->xbzrle_cache_size < qemu_target_page_size() ||
1249 !is_power_of_2(params->xbzrle_cache_size))) {
1250 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1251 "xbzrle_cache_size",
1252 "is invalid, it should be bigger than target page size"
1253 " and a power of 2");
1254 return false;
1255 }
1256
1257 if (params->has_max_cpu_throttle &&
1258 (params->max_cpu_throttle < params->cpu_throttle_initial ||
1259 params->max_cpu_throttle > 99)) {
1260 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1261 "max_cpu_throttle",
1262 "an integer in the range of cpu_throttle_initial to 99");
1263 return false;
1264 }
1265
1266 if (params->has_announce_initial &&
1267 params->announce_initial > 100000) {
1268 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1269 "announce_initial",
1270 "is invalid, it must be less than 100000 ms");
1271 return false;
1272 }
1273 if (params->has_announce_max &&
1274 params->announce_max > 100000) {
1275 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1276 "announce_max",
1277 "is invalid, it must be less than 100000 ms");
1278 return false;
1279 }
1280 if (params->has_announce_rounds &&
1281 params->announce_rounds > 1000) {
1282 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1283 "announce_rounds",
1284 "is invalid, it must be in the range of 0 to 1000");
1285 return false;
1286 }
1287 if (params->has_announce_step &&
1288 (params->announce_step < 1 ||
1289 params->announce_step > 10000)) {
1290 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
1291 "announce_step",
1292 "is invalid, it must be in the range of 1 to 10000 ms");
1293 return false;
1294 }
1295 return true;
1296 }
1297
1298 static void migrate_params_test_apply(MigrateSetParameters *params,
1299 MigrationParameters *dest)
1300 {
1301 *dest = migrate_get_current()->parameters;
1302
1303 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1304
1305 if (params->has_compress_level) {
1306 dest->compress_level = params->compress_level;
1307 }
1308
1309 if (params->has_compress_threads) {
1310 dest->compress_threads = params->compress_threads;
1311 }
1312
1313 if (params->has_compress_wait_thread) {
1314 dest->compress_wait_thread = params->compress_wait_thread;
1315 }
1316
1317 if (params->has_decompress_threads) {
1318 dest->decompress_threads = params->decompress_threads;
1319 }
1320
1321 if (params->has_throttle_trigger_threshold) {
1322 dest->throttle_trigger_threshold = params->throttle_trigger_threshold;
1323 }
1324
1325 if (params->has_cpu_throttle_initial) {
1326 dest->cpu_throttle_initial = params->cpu_throttle_initial;
1327 }
1328
1329 if (params->has_cpu_throttle_increment) {
1330 dest->cpu_throttle_increment = params->cpu_throttle_increment;
1331 }
1332
1333 if (params->has_cpu_throttle_tailslow) {
1334 dest->cpu_throttle_tailslow = params->cpu_throttle_tailslow;
1335 }
1336
1337 if (params->has_tls_creds) {
1338 assert(params->tls_creds->type == QTYPE_QSTRING);
1339 dest->tls_creds = g_strdup(params->tls_creds->u.s);
1340 }
1341
1342 if (params->has_tls_hostname) {
1343 assert(params->tls_hostname->type == QTYPE_QSTRING);
1344 dest->tls_hostname = g_strdup(params->tls_hostname->u.s);
1345 }
1346
1347 if (params->has_max_bandwidth) {
1348 dest->max_bandwidth = params->max_bandwidth;
1349 }
1350
1351 if (params->has_downtime_limit) {
1352 dest->downtime_limit = params->downtime_limit;
1353 }
1354
1355 if (params->has_x_checkpoint_delay) {
1356 dest->x_checkpoint_delay = params->x_checkpoint_delay;
1357 }
1358
1359 if (params->has_block_incremental) {
1360 dest->block_incremental = params->block_incremental;
1361 }
1362 if (params->has_multifd_channels) {
1363 dest->multifd_channels = params->multifd_channels;
1364 }
1365 if (params->has_multifd_compression) {
1366 dest->multifd_compression = params->multifd_compression;
1367 }
1368 if (params->has_xbzrle_cache_size) {
1369 dest->xbzrle_cache_size = params->xbzrle_cache_size;
1370 }
1371 if (params->has_max_postcopy_bandwidth) {
1372 dest->max_postcopy_bandwidth = params->max_postcopy_bandwidth;
1373 }
1374 if (params->has_max_cpu_throttle) {
1375 dest->max_cpu_throttle = params->max_cpu_throttle;
1376 }
1377 if (params->has_announce_initial) {
1378 dest->announce_initial = params->announce_initial;
1379 }
1380 if (params->has_announce_max) {
1381 dest->announce_max = params->announce_max;
1382 }
1383 if (params->has_announce_rounds) {
1384 dest->announce_rounds = params->announce_rounds;
1385 }
1386 if (params->has_announce_step) {
1387 dest->announce_step = params->announce_step;
1388 }
1389 }
1390
1391 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
1392 {
1393 MigrationState *s = migrate_get_current();
1394
1395 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1396
1397 if (params->has_compress_level) {
1398 s->parameters.compress_level = params->compress_level;
1399 }
1400
1401 if (params->has_compress_threads) {
1402 s->parameters.compress_threads = params->compress_threads;
1403 }
1404
1405 if (params->has_compress_wait_thread) {
1406 s->parameters.compress_wait_thread = params->compress_wait_thread;
1407 }
1408
1409 if (params->has_decompress_threads) {
1410 s->parameters.decompress_threads = params->decompress_threads;
1411 }
1412
1413 if (params->has_throttle_trigger_threshold) {
1414 s->parameters.throttle_trigger_threshold = params->throttle_trigger_threshold;
1415 }
1416
1417 if (params->has_cpu_throttle_initial) {
1418 s->parameters.cpu_throttle_initial = params->cpu_throttle_initial;
1419 }
1420
1421 if (params->has_cpu_throttle_increment) {
1422 s->parameters.cpu_throttle_increment = params->cpu_throttle_increment;
1423 }
1424
1425 if (params->has_cpu_throttle_tailslow) {
1426 s->parameters.cpu_throttle_tailslow = params->cpu_throttle_tailslow;
1427 }
1428
1429 if (params->has_tls_creds) {
1430 g_free(s->parameters.tls_creds);
1431 assert(params->tls_creds->type == QTYPE_QSTRING);
1432 s->parameters.tls_creds = g_strdup(params->tls_creds->u.s);
1433 }
1434
1435 if (params->has_tls_hostname) {
1436 g_free(s->parameters.tls_hostname);
1437 assert(params->tls_hostname->type == QTYPE_QSTRING);
1438 s->parameters.tls_hostname = g_strdup(params->tls_hostname->u.s);
1439 }
1440
1441 if (params->has_tls_authz) {
1442 g_free(s->parameters.tls_authz);
1443 assert(params->tls_authz->type == QTYPE_QSTRING);
1444 s->parameters.tls_authz = g_strdup(params->tls_authz->u.s);
1445 }
1446
1447 if (params->has_max_bandwidth) {
1448 s->parameters.max_bandwidth = params->max_bandwidth;
1449 if (s->to_dst_file && !migration_in_postcopy()) {
1450 qemu_file_set_rate_limit(s->to_dst_file,
1451 s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
1452 }
1453 }
1454
1455 if (params->has_downtime_limit) {
1456 s->parameters.downtime_limit = params->downtime_limit;
1457 }
1458
1459 if (params->has_x_checkpoint_delay) {
1460 s->parameters.x_checkpoint_delay = params->x_checkpoint_delay;
1461 if (migration_in_colo_state()) {
1462 colo_checkpoint_notify(s);
1463 }
1464 }
1465
1466 if (params->has_block_incremental) {
1467 s->parameters.block_incremental = params->block_incremental;
1468 }
1469 if (params->has_multifd_channels) {
1470 s->parameters.multifd_channels = params->multifd_channels;
1471 }
1472 if (params->has_multifd_compression) {
1473 s->parameters.multifd_compression = params->multifd_compression;
1474 }
1475 if (params->has_xbzrle_cache_size) {
1476 s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
1477 xbzrle_cache_resize(params->xbzrle_cache_size, errp);
1478 }
1479 if (params->has_max_postcopy_bandwidth) {
1480 s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth;
1481 if (s->to_dst_file && migration_in_postcopy()) {
1482 qemu_file_set_rate_limit(s->to_dst_file,
1483 s->parameters.max_postcopy_bandwidth / XFER_LIMIT_RATIO);
1484 }
1485 }
1486 if (params->has_max_cpu_throttle) {
1487 s->parameters.max_cpu_throttle = params->max_cpu_throttle;
1488 }
1489 if (params->has_announce_initial) {
1490 s->parameters.announce_initial = params->announce_initial;
1491 }
1492 if (params->has_announce_max) {
1493 s->parameters.announce_max = params->announce_max;
1494 }
1495 if (params->has_announce_rounds) {
1496 s->parameters.announce_rounds = params->announce_rounds;
1497 }
1498 if (params->has_announce_step) {
1499 s->parameters.announce_step = params->announce_step;
1500 }
1501 }
1502
1503 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
1504 {
1505 MigrationParameters tmp;
1506
1507 /* TODO Rewrite "" to null instead */
1508 if (params->has_tls_creds
1509 && params->tls_creds->type == QTYPE_QNULL) {
1510 qobject_unref(params->tls_creds->u.n);
1511 params->tls_creds->type = QTYPE_QSTRING;
1512 params->tls_creds->u.s = strdup("");
1513 }
1514 /* TODO Rewrite "" to null instead */
1515 if (params->has_tls_hostname
1516 && params->tls_hostname->type == QTYPE_QNULL) {
1517 qobject_unref(params->tls_hostname->u.n);
1518 params->tls_hostname->type = QTYPE_QSTRING;
1519 params->tls_hostname->u.s = strdup("");
1520 }
1521
1522 migrate_params_test_apply(params, &tmp);
1523
1524 if (!migrate_params_check(&tmp, errp)) {
1525 /* Invalid parameter */
1526 return;
1527 }
1528
1529 migrate_params_apply(params, errp);
1530 }
1531
1532
1533 void qmp_migrate_start_postcopy(Error **errp)
1534 {
1535 MigrationState *s = migrate_get_current();
1536
1537 if (!migrate_postcopy()) {
1538 error_setg(errp, "Enable postcopy with migrate_set_capability before"
1539 " the start of migration");
1540 return;
1541 }
1542
1543 if (s->state == MIGRATION_STATUS_NONE) {
1544 error_setg(errp, "Postcopy must be started after migration has been"
1545 " started");
1546 return;
1547 }
1548 /*
1549 * we don't error if migration has finished since that would be racy
1550 * with issuing this command.
1551 */
1552 atomic_set(&s->start_postcopy, true);
1553 }
1554
1555 /* shared migration helpers */
1556
1557 void migrate_set_state(int *state, int old_state, int new_state)
1558 {
1559 assert(new_state < MIGRATION_STATUS__MAX);
1560 if (atomic_cmpxchg(state, old_state, new_state) == old_state) {
1561 trace_migrate_set_state(MigrationStatus_str(new_state));
1562 migrate_generate_event(new_state);
1563 }
1564 }
1565
1566 static MigrationCapabilityStatusList *migrate_cap_add(
1567 MigrationCapabilityStatusList *list,
1568 MigrationCapability index,
1569 bool state)
1570 {
1571 MigrationCapabilityStatusList *cap;
1572
1573 cap = g_new0(MigrationCapabilityStatusList, 1);
1574 cap->value = g_new0(MigrationCapabilityStatus, 1);
1575 cap->value->capability = index;
1576 cap->value->state = state;
1577 cap->next = list;
1578
1579 return cap;
1580 }
1581
1582 void migrate_set_block_enabled(bool value, Error **errp)
1583 {
1584 MigrationCapabilityStatusList *cap;
1585
1586 cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value);
1587 qmp_migrate_set_capabilities(cap, errp);
1588 qapi_free_MigrationCapabilityStatusList(cap);
1589 }
1590
1591 static void migrate_set_block_incremental(MigrationState *s, bool value)
1592 {
1593 s->parameters.block_incremental = value;
1594 }
1595
1596 static void block_cleanup_parameters(MigrationState *s)
1597 {
1598 if (s->must_remove_block_options) {
1599 /* setting to false can never fail */
1600 migrate_set_block_enabled(false, &error_abort);
1601 migrate_set_block_incremental(s, false);
1602 s->must_remove_block_options = false;
1603 }
1604 }
1605
1606 static void migrate_fd_cleanup(MigrationState *s)
1607 {
1608 qemu_bh_delete(s->cleanup_bh);
1609 s->cleanup_bh = NULL;
1610
1611 qemu_savevm_state_cleanup();
1612
1613 if (s->to_dst_file) {
1614 QEMUFile *tmp;
1615
1616 trace_migrate_fd_cleanup();
1617 qemu_mutex_unlock_iothread();
1618 if (s->migration_thread_running) {
1619 qemu_thread_join(&s->thread);
1620 s->migration_thread_running = false;
1621 }
1622 qemu_mutex_lock_iothread();
1623
1624 multifd_save_cleanup();
1625 qemu_mutex_lock(&s->qemu_file_lock);
1626 tmp = s->to_dst_file;
1627 s->to_dst_file = NULL;
1628 qemu_mutex_unlock(&s->qemu_file_lock);
1629 /*
1630 * Close the file handle without the lock to make sure the
1631 * critical section won't block for long.
1632 */
1633 qemu_fclose(tmp);
1634 }
1635
1636 assert(!migration_is_active(s));
1637
1638 if (s->state == MIGRATION_STATUS_CANCELLING) {
1639 migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
1640 MIGRATION_STATUS_CANCELLED);
1641 }
1642
1643 if (s->error) {
1644 /* It is used on info migrate. We can't free it */
1645 error_report_err(error_copy(s->error));
1646 }
1647 notifier_list_notify(&migration_state_notifiers, s);
1648 block_cleanup_parameters(s);
1649 }
1650
1651 static void migrate_fd_cleanup_schedule(MigrationState *s)
1652 {
1653 /*
1654 * Ref the state for bh, because it may be called when
1655 * there're already no other refs
1656 */
1657 object_ref(OBJECT(s));
1658 qemu_bh_schedule(s->cleanup_bh);
1659 }
1660
1661 static void migrate_fd_cleanup_bh(void *opaque)
1662 {
1663 MigrationState *s = opaque;
1664 migrate_fd_cleanup(s);
1665 object_unref(OBJECT(s));
1666 }
1667
1668 void migrate_set_error(MigrationState *s, const Error *error)
1669 {
1670 QEMU_LOCK_GUARD(&s->error_mutex);
1671 if (!s->error) {
1672 s->error = error_copy(error);
1673 }
1674 }
1675
1676 void migrate_fd_error(MigrationState *s, const Error *error)
1677 {
1678 trace_migrate_fd_error(error_get_pretty(error));
1679 assert(s->to_dst_file == NULL);
1680 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
1681 MIGRATION_STATUS_FAILED);
1682 migrate_set_error(s, error);
1683 }
1684
1685 static void migrate_fd_cancel(MigrationState *s)
1686 {
1687 int old_state ;
1688 QEMUFile *f = migrate_get_current()->to_dst_file;
1689 trace_migrate_fd_cancel();
1690
1691 if (s->rp_state.from_dst_file) {
1692 /* shutdown the rp socket, so causing the rp thread to shutdown */
1693 qemu_file_shutdown(s->rp_state.from_dst_file);
1694 }
1695
1696 do {
1697 old_state = s->state;
1698 if (!migration_is_running(old_state)) {
1699 break;
1700 }
1701 /* If the migration is paused, kick it out of the pause */
1702 if (old_state == MIGRATION_STATUS_PRE_SWITCHOVER) {
1703 qemu_sem_post(&s->pause_sem);
1704 }
1705 migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
1706 } while (s->state != MIGRATION_STATUS_CANCELLING);
1707
1708 /*
1709 * If we're unlucky the migration code might be stuck somewhere in a
1710 * send/write while the network has failed and is waiting to timeout;
1711 * if we've got shutdown(2) available then we can force it to quit.
1712 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1713 * called in a bh, so there is no race against this cancel.
1714 */
1715 if (s->state == MIGRATION_STATUS_CANCELLING && f) {
1716 qemu_file_shutdown(f);
1717 }
1718 if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
1719 Error *local_err = NULL;
1720
1721 bdrv_invalidate_cache_all(&local_err);
1722 if (local_err) {
1723 error_report_err(local_err);
1724 } else {
1725 s->block_inactive = false;
1726 }
1727 }
1728 }
1729
1730 void add_migration_state_change_notifier(Notifier *notify)
1731 {
1732 notifier_list_add(&migration_state_notifiers, notify);
1733 }
1734
1735 void remove_migration_state_change_notifier(Notifier *notify)
1736 {
1737 notifier_remove(notify);
1738 }
1739
1740 bool migration_in_setup(MigrationState *s)
1741 {
1742 return s->state == MIGRATION_STATUS_SETUP;
1743 }
1744
1745 bool migration_has_finished(MigrationState *s)
1746 {
1747 return s->state == MIGRATION_STATUS_COMPLETED;
1748 }
1749
1750 bool migration_has_failed(MigrationState *s)
1751 {
1752 return (s->state == MIGRATION_STATUS_CANCELLED ||
1753 s->state == MIGRATION_STATUS_FAILED);
1754 }
1755
1756 bool migration_in_postcopy(void)
1757 {
1758 MigrationState *s = migrate_get_current();
1759
1760 switch (s->state) {
1761 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1762 case MIGRATION_STATUS_POSTCOPY_PAUSED:
1763 case MIGRATION_STATUS_POSTCOPY_RECOVER:
1764 return true;
1765 default:
1766 return false;
1767 }
1768 }
1769
1770 bool migration_in_postcopy_after_devices(MigrationState *s)
1771 {
1772 return migration_in_postcopy() && s->postcopy_after_devices;
1773 }
1774
1775 bool migration_is_idle(void)
1776 {
1777 MigrationState *s = current_migration;
1778
1779 if (!s) {
1780 return true;
1781 }
1782
1783 switch (s->state) {
1784 case MIGRATION_STATUS_NONE:
1785 case MIGRATION_STATUS_CANCELLED:
1786 case MIGRATION_STATUS_COMPLETED:
1787 case MIGRATION_STATUS_FAILED:
1788 return true;
1789 case MIGRATION_STATUS_SETUP:
1790 case MIGRATION_STATUS_CANCELLING:
1791 case MIGRATION_STATUS_ACTIVE:
1792 case MIGRATION_STATUS_POSTCOPY_ACTIVE:
1793 case MIGRATION_STATUS_COLO:
1794 case MIGRATION_STATUS_PRE_SWITCHOVER:
1795 case MIGRATION_STATUS_DEVICE:
1796 case MIGRATION_STATUS_WAIT_UNPLUG:
1797 return false;
1798 case MIGRATION_STATUS__MAX:
1799 g_assert_not_reached();
1800 }
1801
1802 return false;
1803 }
1804
1805 bool migration_is_active(MigrationState *s)
1806 {
1807 return (s->state == MIGRATION_STATUS_ACTIVE ||
1808 s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
1809 }
1810
1811 void migrate_init(MigrationState *s)
1812 {
1813 /*
1814 * Reinitialise all migration state, except
1815 * parameters/capabilities that the user set, and
1816 * locks.
1817 */
1818 s->cleanup_bh = 0;
1819 s->to_dst_file = NULL;
1820 s->state = MIGRATION_STATUS_NONE;
1821 s->rp_state.from_dst_file = NULL;
1822 s->rp_state.error = false;
1823 s->mbps = 0.0;
1824 s->pages_per_second = 0.0;
1825 s->downtime = 0;
1826 s->expected_downtime = 0;
1827 s->setup_time = 0;
1828 s->start_postcopy = false;
1829 s->postcopy_after_devices = false;
1830 s->migration_thread_running = false;
1831 error_free(s->error);
1832 s->error = NULL;
1833
1834 migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
1835
1836 s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1837 s->total_time = 0;
1838 s->vm_was_running = false;
1839 s->iteration_initial_bytes = 0;
1840 s->threshold_size = 0;
1841 }
1842
1843 static GSList *migration_blockers;
1844
1845 int migrate_add_blocker(Error *reason, Error **errp)
1846 {
1847 if (only_migratable) {
1848 error_propagate_prepend(errp, error_copy(reason),
1849 "disallowing migration blocker "
1850 "(--only-migratable) for: ");
1851 return -EACCES;
1852 }
1853
1854 if (migration_is_idle()) {
1855 migration_blockers = g_slist_prepend(migration_blockers, reason);
1856 return 0;
1857 }
1858
1859 error_propagate_prepend(errp, error_copy(reason),
1860 "disallowing migration blocker "
1861 "(migration in progress) for: ");
1862 return -EBUSY;
1863 }
1864
1865 void migrate_del_blocker(Error *reason)
1866 {
1867 migration_blockers = g_slist_remove(migration_blockers, reason);
1868 }
1869
1870 void qmp_migrate_incoming(const char *uri, Error **errp)
1871 {
1872 Error *local_err = NULL;
1873 static bool once = true;
1874
1875 if (!deferred_incoming) {
1876 error_setg(errp, "For use with '-incoming defer'");
1877 return;
1878 }
1879 if (!once) {
1880 error_setg(errp, "The incoming migration has already been started");
1881 return;
1882 }
1883
1884 qemu_start_incoming_migration(uri, &local_err);
1885
1886 if (local_err) {
1887 error_propagate(errp, local_err);
1888 return;
1889 }
1890
1891 once = false;
1892 }
1893
1894 void qmp_migrate_recover(const char *uri, Error **errp)
1895 {
1896 MigrationIncomingState *mis = migration_incoming_get_current();
1897
1898 if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
1899 error_setg(errp, "Migrate recover can only be run "
1900 "when postcopy is paused.");
1901 return;
1902 }
1903
1904 if (atomic_cmpxchg(&mis->postcopy_recover_triggered,
1905 false, true) == true) {
1906 error_setg(errp, "Migrate recovery is triggered already");
1907 return;
1908 }
1909
1910 /*
1911 * Note that this call will never start a real migration; it will
1912 * only re-setup the migration stream and poke existing migration
1913 * to continue using that newly established channel.
1914 */
1915 qemu_start_incoming_migration(uri, errp);
1916 }
1917
1918 void qmp_migrate_pause(Error **errp)
1919 {
1920 MigrationState *ms = migrate_get_current();
1921 MigrationIncomingState *mis = migration_incoming_get_current();
1922 int ret;
1923
1924 if (ms->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
1925 /* Source side, during postcopy */
1926 qemu_mutex_lock(&ms->qemu_file_lock);
1927 ret = qemu_file_shutdown(ms->to_dst_file);
1928 qemu_mutex_unlock(&ms->qemu_file_lock);
1929 if (ret) {
1930 error_setg(errp, "Failed to pause source migration");
1931 }
1932 return;
1933 }
1934
1935 if (mis->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
1936 ret = qemu_file_shutdown(mis->from_src_file);
1937 if (ret) {
1938 error_setg(errp, "Failed to pause destination migration");
1939 }
1940 return;
1941 }
1942
1943 error_setg(errp, "migrate-pause is currently only supported "
1944 "during postcopy-active state");
1945 }
1946
1947 bool migration_is_blocked(Error **errp)
1948 {
1949 if (qemu_savevm_state_blocked(errp)) {
1950 return true;
1951 }
1952
1953 if (migration_blockers) {
1954 error_propagate(errp, error_copy(migration_blockers->data));
1955 return true;
1956 }
1957
1958 return false;
1959 }
1960
1961 /* Returns true if continue to migrate, or false if error detected */
1962 static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
1963 bool resume, Error **errp)
1964 {
1965 Error *local_err = NULL;
1966
1967 if (resume) {
1968 if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
1969 error_setg(errp, "Cannot resume if there is no "
1970 "paused migration");
1971 return false;
1972 }
1973
1974 /*
1975 * Postcopy recovery won't work well with release-ram
1976 * capability since release-ram will drop the page buffer as
1977 * long as the page is put into the send buffer. So if there
1978 * is a network failure happened, any page buffers that have
1979 * not yet reached the destination VM but have already been
1980 * sent from the source VM will be lost forever. Let's refuse
1981 * the client from resuming such a postcopy migration.
1982 * Luckily release-ram was designed to only be used when src
1983 * and destination VMs are on the same host, so it should be
1984 * fine.
1985 */
1986 if (migrate_release_ram()) {
1987 error_setg(errp, "Postcopy recovery cannot work "
1988 "when release-ram capability is set");
1989 return false;
1990 }
1991
1992 /* This is a resume, skip init status */
1993 return true;
1994 }
1995
1996 if (migration_is_running(s->state)) {
1997 error_setg(errp, QERR_MIGRATION_ACTIVE);
1998 return false;
1999 }
2000
2001 if (runstate_check(RUN_STATE_INMIGRATE)) {
2002 error_setg(errp, "Guest is waiting for an incoming migration");
2003 return false;
2004 }
2005
2006 if (migration_is_blocked(errp)) {
2007 return false;
2008 }
2009
2010 if (blk || blk_inc) {
2011 if (migrate_use_block() || migrate_use_block_incremental()) {
2012 error_setg(errp, "Command options are incompatible with "
2013 "current migration capabilities");
2014 return false;
2015 }
2016 migrate_set_block_enabled(true, &local_err);
2017 if (local_err) {
2018 error_propagate(errp, local_err);
2019 return false;
2020 }
2021 s->must_remove_block_options = true;
2022 }
2023
2024 if (blk_inc) {
2025 migrate_set_block_incremental(s, true);
2026 }
2027
2028 migrate_init(s);
2029 /*
2030 * set ram_counters memory to zero for a
2031 * new migration
2032 */
2033 memset(&ram_counters, 0, sizeof(ram_counters));
2034
2035 return true;
2036 }
2037
2038 void qmp_migrate(const char *uri, bool has_blk, bool blk,
2039 bool has_inc, bool inc, bool has_detach, bool detach,
2040 bool has_resume, bool resume, Error **errp)
2041 {
2042 Error *local_err = NULL;
2043 MigrationState *s = migrate_get_current();
2044 const char *p;
2045
2046 if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
2047 has_resume && resume, errp)) {
2048 /* Error detected, put into errp */
2049 return;
2050 }
2051
2052 if (strstart(uri, "tcp:", &p)) {
2053 tcp_start_outgoing_migration(s, p, &local_err);
2054 #ifdef CONFIG_RDMA
2055 } else if (strstart(uri, "rdma:", &p)) {
2056 rdma_start_outgoing_migration(s, p, &local_err);
2057 #endif
2058 } else if (strstart(uri, "exec:", &p)) {
2059 exec_start_outgoing_migration(s, p, &local_err);
2060 } else if (strstart(uri, "unix:", &p)) {
2061 unix_start_outgoing_migration(s, p, &local_err);
2062 } else if (strstart(uri, "fd:", &p)) {
2063 fd_start_outgoing_migration(s, p, &local_err);
2064 } else {
2065 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
2066 "a valid migration protocol");
2067 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
2068 MIGRATION_STATUS_FAILED);
2069 block_cleanup_parameters(s);
2070 return;
2071 }
2072
2073 if (local_err) {
2074 migrate_fd_error(s, local_err);
2075 error_propagate(errp, local_err);
2076 return;
2077 }
2078 }
2079
2080 void qmp_migrate_cancel(Error **errp)
2081 {
2082 migrate_fd_cancel(migrate_get_current());
2083 }
2084
2085 void qmp_migrate_continue(MigrationStatus state, Error **errp)
2086 {
2087 MigrationState *s = migrate_get_current();
2088 if (s->state != state) {
2089 error_setg(errp, "Migration not in expected state: %s",
2090 MigrationStatus_str(s->state));
2091 return;
2092 }
2093 qemu_sem_post(&s->pause_sem);
2094 }
2095
2096 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
2097 {
2098 MigrateSetParameters p = {
2099 .has_xbzrle_cache_size = true,
2100 .xbzrle_cache_size = value,
2101 };
2102
2103 qmp_migrate_set_parameters(&p, errp);
2104 }
2105
2106 int64_t qmp_query_migrate_cache_size(Error **errp)
2107 {
2108 return migrate_xbzrle_cache_size();
2109 }
2110
2111 void qmp_migrate_set_speed(int64_t value, Error **errp)
2112 {
2113 MigrateSetParameters p = {
2114 .has_max_bandwidth = true,
2115 .max_bandwidth = value,
2116 };
2117
2118 qmp_migrate_set_parameters(&p, errp);
2119 }
2120
2121 void qmp_migrate_set_downtime(double value, Error **errp)
2122 {
2123 if (value < 0 || value > MAX_MIGRATE_DOWNTIME_SECONDS) {
2124 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
2125 "downtime_limit",
2126 "an integer in the range of 0 to "
2127 stringify(MAX_MIGRATE_DOWNTIME_SECONDS)" seconds");
2128 return;
2129 }
2130
2131 value *= 1000; /* Convert to milliseconds */
2132
2133 MigrateSetParameters p = {
2134 .has_downtime_limit = true,
2135 .downtime_limit = (int64_t)value,
2136 };
2137
2138 qmp_migrate_set_parameters(&p, errp);
2139 }
2140
2141 bool migrate_release_ram(void)
2142 {
2143 MigrationState *s;
2144
2145 s = migrate_get_current();
2146
2147 return s->enabled_capabilities[MIGRATION_CAPABILITY_RELEASE_RAM];
2148 }
2149
2150 bool migrate_postcopy_ram(void)
2151 {
2152 MigrationState *s;
2153
2154 s = migrate_get_current();
2155
2156 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM];
2157 }
2158
2159 bool migrate_postcopy(void)
2160 {
2161 return migrate_postcopy_ram() || migrate_dirty_bitmaps();
2162 }
2163
2164 bool migrate_auto_converge(void)
2165 {
2166 MigrationState *s;
2167
2168 s = migrate_get_current();
2169
2170 return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
2171 }
2172
2173 bool migrate_zero_blocks(void)
2174 {
2175 MigrationState *s;
2176
2177 s = migrate_get_current();
2178
2179 return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
2180 }
2181
2182 bool migrate_postcopy_blocktime(void)
2183 {
2184 MigrationState *s;
2185
2186 s = migrate_get_current();
2187
2188 return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME];
2189 }
2190
2191 bool migrate_use_compression(void)
2192 {
2193 MigrationState *s;
2194
2195 s = migrate_get_current();
2196
2197 return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
2198 }
2199
2200 int migrate_compress_level(void)
2201 {
2202 MigrationState *s;
2203
2204 s = migrate_get_current();
2205
2206 return s->parameters.compress_level;
2207 }
2208
2209 int migrate_compress_threads(void)
2210 {
2211 MigrationState *s;
2212
2213 s = migrate_get_current();
2214
2215 return s->parameters.compress_threads;
2216 }
2217
2218 int migrate_compress_wait_thread(void)
2219 {
2220 MigrationState *s;
2221
2222 s = migrate_get_current();
2223
2224 return s->parameters.compress_wait_thread;
2225 }
2226
2227 int migrate_decompress_threads(void)
2228 {
2229 MigrationState *s;
2230
2231 s = migrate_get_current();
2232
2233 return s->parameters.decompress_threads;
2234 }
2235
2236 bool migrate_dirty_bitmaps(void)
2237 {
2238 MigrationState *s;
2239
2240 s = migrate_get_current();
2241
2242 return s->enabled_capabilities[MIGRATION_CAPABILITY_DIRTY_BITMAPS];
2243 }
2244
2245 bool migrate_ignore_shared(void)
2246 {
2247 MigrationState *s;
2248
2249 s = migrate_get_current();
2250
2251 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_IGNORE_SHARED];
2252 }
2253
2254 bool migrate_validate_uuid(void)
2255 {
2256 MigrationState *s;
2257
2258 s = migrate_get_current();
2259
2260 return s->enabled_capabilities[MIGRATION_CAPABILITY_VALIDATE_UUID];
2261 }
2262
2263 bool migrate_use_events(void)
2264 {
2265 MigrationState *s;
2266
2267 s = migrate_get_current();
2268
2269 return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
2270 }
2271
2272 bool migrate_use_multifd(void)
2273 {
2274 MigrationState *s;
2275
2276 s = migrate_get_current();
2277
2278 return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD];
2279 }
2280
2281 bool migrate_pause_before_switchover(void)
2282 {
2283 MigrationState *s;
2284
2285 s = migrate_get_current();
2286
2287 return s->enabled_capabilities[
2288 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
2289 }
2290
2291 int migrate_multifd_channels(void)
2292 {
2293 MigrationState *s;
2294
2295 s = migrate_get_current();
2296
2297 return s->parameters.multifd_channels;
2298 }
2299
2300 MultiFDCompression migrate_multifd_compression(void)
2301 {
2302 MigrationState *s;
2303
2304 s = migrate_get_current();
2305
2306 return s->parameters.multifd_compression;
2307 }
2308
2309 int migrate_multifd_zlib_level(void)
2310 {
2311 MigrationState *s;
2312
2313 s = migrate_get_current();
2314
2315 return s->parameters.multifd_zlib_level;
2316 }
2317
2318 int migrate_multifd_zstd_level(void)
2319 {
2320 MigrationState *s;
2321
2322 s = migrate_get_current();
2323
2324 return s->parameters.multifd_zstd_level;
2325 }
2326
2327 int migrate_use_xbzrle(void)
2328 {
2329 MigrationState *s;
2330
2331 s = migrate_get_current();
2332
2333 return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
2334 }
2335
2336 int64_t migrate_xbzrle_cache_size(void)
2337 {
2338 MigrationState *s;
2339
2340 s = migrate_get_current();
2341
2342 return s->parameters.xbzrle_cache_size;
2343 }
2344
2345 static int64_t migrate_max_postcopy_bandwidth(void)
2346 {
2347 MigrationState *s;
2348
2349 s = migrate_get_current();
2350
2351 return s->parameters.max_postcopy_bandwidth;
2352 }
2353
2354 bool migrate_use_block(void)
2355 {
2356 MigrationState *s;
2357
2358 s = migrate_get_current();
2359
2360 return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK];
2361 }
2362
2363 bool migrate_use_return_path(void)
2364 {
2365 MigrationState *s;
2366
2367 s = migrate_get_current();
2368
2369 return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH];
2370 }
2371
2372 bool migrate_use_block_incremental(void)
2373 {
2374 MigrationState *s;
2375
2376 s = migrate_get_current();
2377
2378 return s->parameters.block_incremental;
2379 }
2380
2381 /* migration thread support */
2382 /*
2383 * Something bad happened to the RP stream, mark an error
2384 * The caller shall print or trace something to indicate why
2385 */
2386 static void mark_source_rp_bad(MigrationState *s)
2387 {
2388 s->rp_state.error = true;
2389 }
2390
2391 static struct rp_cmd_args {
2392 ssize_t len; /* -1 = variable */
2393 const char *name;
2394 } rp_cmd_args[] = {
2395 [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
2396 [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
2397 [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
2398 [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
2399 [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
2400 [MIG_RP_MSG_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
2401 [MIG_RP_MSG_RESUME_ACK] = { .len = 4, .name = "RESUME_ACK" },
2402 [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
2403 };
2404
2405 /*
2406 * Process a request for pages received on the return path,
2407 * We're allowed to send more than requested (e.g. to round to our page size)
2408 * and we don't need to send pages that have already been sent.
2409 */
2410 static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
2411 ram_addr_t start, size_t len)
2412 {
2413 long our_host_ps = qemu_real_host_page_size;
2414
2415 trace_migrate_handle_rp_req_pages(rbname, start, len);
2416
2417 /*
2418 * Since we currently insist on matching page sizes, just sanity check
2419 * we're being asked for whole host pages.
2420 */
2421 if (start & (our_host_ps-1) ||
2422 (len & (our_host_ps-1))) {
2423 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
2424 " len: %zd", __func__, start, len);
2425 mark_source_rp_bad(ms);
2426 return;
2427 }
2428
2429 if (ram_save_queue_pages(rbname, start, len)) {
2430 mark_source_rp_bad(ms);
2431 }
2432 }
2433
2434 /* Return true to retry, false to quit */
2435 static bool postcopy_pause_return_path_thread(MigrationState *s)
2436 {
2437 trace_postcopy_pause_return_path();
2438
2439 qemu_sem_wait(&s->postcopy_pause_rp_sem);
2440
2441 trace_postcopy_pause_return_path_continued();
2442
2443 return true;
2444 }
2445
2446 static int migrate_handle_rp_recv_bitmap(MigrationState *s, char *block_name)
2447 {
2448 RAMBlock *block = qemu_ram_block_by_name(block_name);
2449
2450 if (!block) {
2451 error_report("%s: invalid block name '%s'", __func__, block_name);
2452 return -EINVAL;
2453 }
2454
2455 /* Fetch the received bitmap and refresh the dirty bitmap */
2456 return ram_dirty_bitmap_reload(s, block);
2457 }
2458
2459 static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value)
2460 {
2461 trace_source_return_path_thread_resume_ack(value);
2462
2463 if (value != MIGRATION_RESUME_ACK_VALUE) {
2464 error_report("%s: illegal resume_ack value %"PRIu32,
2465 __func__, value);
2466 return -1;
2467 }
2468
2469 /* Now both sides are active. */
2470 migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
2471 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2472
2473 /* Notify send thread that time to continue send pages */
2474 qemu_sem_post(&s->rp_state.rp_sem);
2475
2476 return 0;
2477 }
2478
2479 /*
2480 * Handles messages sent on the return path towards the source VM
2481 *
2482 */
2483 static void *source_return_path_thread(void *opaque)
2484 {
2485 MigrationState *ms = opaque;
2486 QEMUFile *rp = ms->rp_state.from_dst_file;
2487 uint16_t header_len, header_type;
2488 uint8_t buf[512];
2489 uint32_t tmp32, sibling_error;
2490 ram_addr_t start = 0; /* =0 to silence warning */
2491 size_t len = 0, expected_len;
2492 int res;
2493
2494 trace_source_return_path_thread_entry();
2495 rcu_register_thread();
2496
2497 retry:
2498 while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
2499 migration_is_setup_or_active(ms->state)) {
2500 trace_source_return_path_thread_loop_top();
2501 header_type = qemu_get_be16(rp);
2502 header_len = qemu_get_be16(rp);
2503
2504 if (qemu_file_get_error(rp)) {
2505 mark_source_rp_bad(ms);
2506 goto out;
2507 }
2508
2509 if (header_type >= MIG_RP_MSG_MAX ||
2510 header_type == MIG_RP_MSG_INVALID) {
2511 error_report("RP: Received invalid message 0x%04x length 0x%04x",
2512 header_type, header_len);
2513 mark_source_rp_bad(ms);
2514 goto out;
2515 }
2516
2517 if ((rp_cmd_args[header_type].len != -1 &&
2518 header_len != rp_cmd_args[header_type].len) ||
2519 header_len > sizeof(buf)) {
2520 error_report("RP: Received '%s' message (0x%04x) with"
2521 "incorrect length %d expecting %zu",
2522 rp_cmd_args[header_type].name, header_type, header_len,
2523 (size_t)rp_cmd_args[header_type].len);
2524 mark_source_rp_bad(ms);
2525 goto out;
2526 }
2527
2528 /* We know we've got a valid header by this point */
2529 res = qemu_get_buffer(rp, buf, header_len);
2530 if (res != header_len) {
2531 error_report("RP: Failed reading data for message 0x%04x"
2532 " read %d expected %d",
2533 header_type, res, header_len);
2534 mark_source_rp_bad(ms);
2535 goto out;
2536 }
2537
2538 /* OK, we have the message and the data */
2539 switch (header_type) {
2540 case MIG_RP_MSG_SHUT:
2541 sibling_error = ldl_be_p(buf);
2542 trace_source_return_path_thread_shut(sibling_error);
2543 if (sibling_error) {
2544 error_report("RP: Sibling indicated error %d", sibling_error);
2545 mark_source_rp_bad(ms);
2546 }
2547 /*
2548 * We'll let the main thread deal with closing the RP
2549 * we could do a shutdown(2) on it, but we're the only user
2550 * anyway, so there's nothing gained.
2551 */
2552 goto out;
2553
2554 case MIG_RP_MSG_PONG:
2555 tmp32 = ldl_be_p(buf);
2556 trace_source_return_path_thread_pong(tmp32);
2557 break;
2558
2559 case MIG_RP_MSG_REQ_PAGES:
2560 start = ldq_be_p(buf);
2561 len = ldl_be_p(buf + 8);
2562 migrate_handle_rp_req_pages(ms, NULL, start, len);
2563 break;
2564
2565 case MIG_RP_MSG_REQ_PAGES_ID:
2566 expected_len = 12 + 1; /* header + termination */
2567
2568 if (header_len >= expected_len) {
2569 start = ldq_be_p(buf);
2570 len = ldl_be_p(buf + 8);
2571 /* Now we expect an idstr */
2572 tmp32 = buf[12]; /* Length of the following idstr */
2573 buf[13 + tmp32] = '\0';
2574 expected_len += tmp32;
2575 }
2576 if (header_len != expected_len) {
2577 error_report("RP: Req_Page_id with length %d expecting %zd",
2578 header_len, expected_len);
2579 mark_source_rp_bad(ms);
2580 goto out;
2581 }
2582 migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
2583 break;
2584
2585 case MIG_RP_MSG_RECV_BITMAP:
2586 if (header_len < 1) {
2587 error_report("%s: missing block name", __func__);
2588 mark_source_rp_bad(ms);
2589 goto out;
2590 }
2591 /* Format: len (1B) + idstr (<255B). This ends the idstr. */
2592 buf[buf[0] + 1] = '\0';
2593 if (migrate_handle_rp_recv_bitmap(ms, (char *)(buf + 1))) {
2594 mark_source_rp_bad(ms);
2595 goto out;
2596 }
2597 break;
2598
2599 case MIG_RP_MSG_RESUME_ACK:
2600 tmp32 = ldl_be_p(buf);
2601 if (migrate_handle_rp_resume_ack(ms, tmp32)) {
2602 mark_source_rp_bad(ms);
2603 goto out;
2604 }
2605 break;
2606
2607 default:
2608 break;
2609 }
2610 }
2611
2612 out:
2613 res = qemu_file_get_error(rp);
2614 if (res) {
2615 if (res == -EIO && migration_in_postcopy()) {
2616 /*
2617 * Maybe there is something we can do: it looks like a
2618 * network down issue, and we pause for a recovery.
2619 */
2620 if (postcopy_pause_return_path_thread(ms)) {
2621 /* Reload rp, reset the rest */
2622 if (rp != ms->rp_state.from_dst_file) {
2623 qemu_fclose(rp);
2624 rp = ms->rp_state.from_dst_file;
2625 }
2626 ms->rp_state.error = false;
2627 goto retry;
2628 }
2629 }
2630
2631 trace_source_return_path_thread_bad_end();
2632 mark_source_rp_bad(ms);
2633 }
2634
2635 trace_source_return_path_thread_end();
2636 ms->rp_state.from_dst_file = NULL;
2637 qemu_fclose(rp);
2638 rcu_unregister_thread();
2639 return NULL;
2640 }
2641
2642 static int open_return_path_on_source(MigrationState *ms,
2643 bool create_thread)
2644 {
2645
2646 ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
2647 if (!ms->rp_state.from_dst_file) {
2648 return -1;
2649 }
2650
2651 trace_open_return_path_on_source();
2652
2653 if (!create_thread) {
2654 /* We're done */
2655 return 0;
2656 }
2657
2658 qemu_thread_create(&ms->rp_state.rp_thread, "return path",
2659 source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
2660
2661 trace_open_return_path_on_source_continue();
2662
2663 return 0;
2664 }
2665
2666 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
2667 static int await_return_path_close_on_source(MigrationState *ms)
2668 {
2669 /*
2670 * If this is a normal exit then the destination will send a SHUT and the
2671 * rp_thread will exit, however if there's an error we need to cause
2672 * it to exit.
2673 */
2674 if (qemu_file_get_error(ms->to_dst_file) && ms->rp_state.from_dst_file) {
2675 /*
2676 * shutdown(2), if we have it, will cause it to unblock if it's stuck
2677 * waiting for the destination.
2678 */
2679 qemu_file_shutdown(ms->rp_state.from_dst_file);
2680 mark_source_rp_bad(ms);
2681 }
2682 trace_await_return_path_close_on_source_joining();
2683 qemu_thread_join(&ms->rp_state.rp_thread);
2684 trace_await_return_path_close_on_source_close();
2685 return ms->rp_state.error;
2686 }
2687
2688 /*
2689 * Switch from normal iteration to postcopy
2690 * Returns non-0 on error
2691 */
2692 static int postcopy_start(MigrationState *ms)
2693 {
2694 int ret;
2695 QIOChannelBuffer *bioc;
2696 QEMUFile *fb;
2697 int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2698 int64_t bandwidth = migrate_max_postcopy_bandwidth();
2699 bool restart_block = false;
2700 int cur_state = MIGRATION_STATUS_ACTIVE;
2701 if (!migrate_pause_before_switchover()) {
2702 migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
2703 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2704 }
2705
2706 trace_postcopy_start();
2707 qemu_mutex_lock_iothread();
2708 trace_postcopy_start_set_run();
2709
2710 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
2711 global_state_store();
2712 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2713 if (ret < 0) {
2714 goto fail;
2715 }
2716
2717 ret = migration_maybe_pause(ms, &cur_state,
2718 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2719 if (ret < 0) {
2720 goto fail;
2721 }
2722
2723 ret = bdrv_inactivate_all();
2724 if (ret < 0) {
2725 goto fail;
2726 }
2727 restart_block = true;
2728
2729 /*
2730 * Cause any non-postcopiable, but iterative devices to
2731 * send out their final data.
2732 */
2733 qemu_savevm_state_complete_precopy(ms->to_dst_file, true, false);
2734
2735 /*
2736 * in Finish migrate and with the io-lock held everything should
2737 * be quiet, but we've potentially still got dirty pages and we
2738 * need to tell the destination to throw any pages it's already received
2739 * that are dirty
2740 */
2741 if (migrate_postcopy_ram()) {
2742 if (ram_postcopy_send_discard_bitmap(ms)) {
2743 error_report("postcopy send discard bitmap failed");
2744 goto fail;
2745 }
2746 }
2747
2748 /*
2749 * send rest of state - note things that are doing postcopy
2750 * will notice we're in POSTCOPY_ACTIVE and not actually
2751 * wrap their state up here
2752 */
2753 /* 0 max-postcopy-bandwidth means unlimited */
2754 if (!bandwidth) {
2755 qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);
2756 } else {
2757 qemu_file_set_rate_limit(ms->to_dst_file, bandwidth / XFER_LIMIT_RATIO);
2758 }
2759 if (migrate_postcopy_ram()) {
2760 /* Ping just for debugging, helps line traces up */
2761 qemu_savevm_send_ping(ms->to_dst_file, 2);
2762 }
2763
2764 /*
2765 * While loading the device state we may trigger page transfer
2766 * requests and the fd must be free to process those, and thus
2767 * the destination must read the whole device state off the fd before
2768 * it starts processing it. Unfortunately the ad-hoc migration format
2769 * doesn't allow the destination to know the size to read without fully
2770 * parsing it through each devices load-state code (especially the open
2771 * coded devices that use get/put).
2772 * So we wrap the device state up in a package with a length at the start;
2773 * to do this we use a qemu_buf to hold the whole of the device state.
2774 */
2775 bioc = qio_channel_buffer_new(4096);
2776 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");
2777 fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
2778 object_unref(OBJECT(bioc));
2779
2780 /*
2781 * Make sure the receiver can get incoming pages before we send the rest
2782 * of the state
2783 */
2784 qemu_savevm_send_postcopy_listen(fb);
2785
2786 qemu_savevm_state_complete_precopy(fb, false, false);
2787 if (migrate_postcopy_ram()) {
2788 qemu_savevm_send_ping(fb, 3);
2789 }
2790
2791 qemu_savevm_send_postcopy_run(fb);
2792
2793 /* <><> end of stuff going into the package */
2794
2795 /* Last point of recovery; as soon as we send the package the destination
2796 * can open devices and potentially start running.
2797 * Lets just check again we've not got any errors.
2798 */
2799 ret = qemu_file_get_error(ms->to_dst_file);
2800 if (ret) {
2801 error_report("postcopy_start: Migration stream errored (pre package)");
2802 goto fail_closefb;
2803 }
2804
2805 restart_block = false;
2806
2807 /* Now send that blob */
2808 if (qemu_savevm_send_packaged(ms->to_dst_file, bioc->data, bioc->usage)) {
2809 goto fail_closefb;
2810 }
2811 qemu_fclose(fb);
2812
2813 /* Send a notify to give a chance for anything that needs to happen
2814 * at the transition to postcopy and after the device state; in particular
2815 * spice needs to trigger a transition now
2816 */
2817 ms->postcopy_after_devices = true;
2818 notifier_list_notify(&migration_state_notifiers, ms);
2819
2820 ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
2821
2822 qemu_mutex_unlock_iothread();
2823
2824 if (migrate_postcopy_ram()) {
2825 /*
2826 * Although this ping is just for debug, it could potentially be
2827 * used for getting a better measurement of downtime at the source.
2828 */
2829 qemu_savevm_send_ping(ms->to_dst_file, 4);
2830 }
2831
2832 if (migrate_release_ram()) {
2833 ram_postcopy_migrated_memory_release(ms);
2834 }
2835
2836 ret = qemu_file_get_error(ms->to_dst_file);
2837 if (ret) {
2838 error_report("postcopy_start: Migration stream errored");
2839 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2840 MIGRATION_STATUS_FAILED);
2841 }
2842
2843 return ret;
2844
2845 fail_closefb:
2846 qemu_fclose(fb);
2847 fail:
2848 migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2849 MIGRATION_STATUS_FAILED);
2850 if (restart_block) {
2851 /* A failure happened early enough that we know the destination hasn't
2852 * accessed block devices, so we're safe to recover.
2853 */
2854 Error *local_err = NULL;
2855
2856 bdrv_invalidate_cache_all(&local_err);
2857 if (local_err) {
2858 error_report_err(local_err);
2859 }
2860 }
2861 qemu_mutex_unlock_iothread();
2862 return -1;
2863 }
2864
2865 /**
2866 * migration_maybe_pause: Pause if required to by
2867 * migrate_pause_before_switchover called with the iothread locked
2868 * Returns: 0 on success
2869 */
2870 static int migration_maybe_pause(MigrationState *s,
2871 int *current_active_state,
2872 int new_state)
2873 {
2874 if (!migrate_pause_before_switchover()) {
2875 return 0;
2876 }
2877
2878 /* Since leaving this state is not atomic with posting the semaphore
2879 * it's possible that someone could have issued multiple migrate_continue
2880 * and the semaphore is incorrectly positive at this point;
2881 * the docs say it's undefined to reinit a semaphore that's already
2882 * init'd, so use timedwait to eat up any existing posts.
2883 */
2884 while (qemu_sem_timedwait(&s->pause_sem, 1) == 0) {
2885 /* This block intentionally left blank */
2886 }
2887
2888 /*
2889 * If the migration is cancelled when it is in the completion phase,
2890 * the migration state is set to MIGRATION_STATUS_CANCELLING.
2891 * So we don't need to wait a semaphore, otherwise we would always
2892 * wait for the 'pause_sem' semaphore.
2893 */
2894 if (s->state != MIGRATION_STATUS_CANCELLING) {
2895 qemu_mutex_unlock_iothread();
2896 migrate_set_state(&s->state, *current_active_state,
2897 MIGRATION_STATUS_PRE_SWITCHOVER);
2898 qemu_sem_wait(&s->pause_sem);
2899 migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
2900 new_state);
2901 *current_active_state = new_state;
2902 qemu_mutex_lock_iothread();
2903 }
2904
2905 return s->state == new_state ? 0 : -EINVAL;
2906 }
2907
2908 /**
2909 * migration_completion: Used by migration_thread when there's not much left.
2910 * The caller 'breaks' the loop when this returns.
2911 *
2912 * @s: Current migration state
2913 */
2914 static void migration_completion(MigrationState *s)
2915 {
2916 int ret;
2917 int current_active_state = s->state;
2918
2919 if (s->state == MIGRATION_STATUS_ACTIVE) {
2920 qemu_mutex_lock_iothread();
2921 s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
2922 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
2923 s->vm_was_running = runstate_is_running();
2924 ret = global_state_store();
2925
2926 if (!ret) {
2927 bool inactivate = !migrate_colo_enabled();
2928 ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
2929 if (ret >= 0) {
2930 ret = migration_maybe_pause(s, &current_active_state,
2931 MIGRATION_STATUS_DEVICE);
2932 }
2933 if (ret >= 0) {
2934 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
2935 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
2936 inactivate);
2937 }
2938 if (inactivate && ret >= 0) {
2939 s->block_inactive = true;
2940 }
2941 }
2942 qemu_mutex_unlock_iothread();
2943
2944 if (ret < 0) {
2945 goto fail;
2946 }
2947 } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
2948 trace_migration_completion_postcopy_end();
2949
2950 qemu_savevm_state_complete_postcopy(s->to_dst_file);
2951 trace_migration_completion_postcopy_end_after_complete();
2952 }
2953
2954 /*
2955 * If rp was opened we must clean up the thread before
2956 * cleaning everything else up (since if there are no failures
2957 * it will wait for the destination to send it's status in
2958 * a SHUT command).
2959 */
2960 if (s->rp_state.from_dst_file) {
2961 int rp_error;
2962 trace_migration_return_path_end_before();
2963 rp_error = await_return_path_close_on_source(s);
2964 trace_migration_return_path_end_after(rp_error);
2965 if (rp_error) {
2966 goto fail_invalidate;
2967 }
2968 }
2969
2970 if (qemu_file_get_error(s->to_dst_file)) {
2971 trace_migration_completion_file_err();
2972 goto fail_invalidate;
2973 }
2974
2975 if (!migrate_colo_enabled()) {
2976 migrate_set_state(&s->state, current_active_state,
2977 MIGRATION_STATUS_COMPLETED);
2978 }
2979
2980 return;
2981
2982 fail_invalidate:
2983 /* If not doing postcopy, vm_start() will be called: let's regain
2984 * control on images.
2985 */
2986 if (s->state == MIGRATION_STATUS_ACTIVE ||
2987 s->state == MIGRATION_STATUS_DEVICE) {
2988 Error *local_err = NULL;
2989
2990 qemu_mutex_lock_iothread();
2991 bdrv_invalidate_cache_all(&local_err);
2992 if (local_err) {
2993 error_report_err(local_err);
2994 } else {
2995 s->block_inactive = false;
2996 }
2997 qemu_mutex_unlock_iothread();
2998 }
2999
3000 fail:
3001 migrate_set_state(&s->state, current_active_state,
3002 MIGRATION_STATUS_FAILED);
3003 }
3004
3005 bool migrate_colo_enabled(void)
3006 {
3007 MigrationState *s = migrate_get_current();
3008 return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
3009 }
3010
3011 typedef enum MigThrError {
3012 /* No error detected */
3013 MIG_THR_ERR_NONE = 0,
3014 /* Detected error, but resumed successfully */
3015 MIG_THR_ERR_RECOVERED = 1,
3016 /* Detected fatal error, need to exit */
3017 MIG_THR_ERR_FATAL = 2,
3018 } MigThrError;
3019
3020 static int postcopy_resume_handshake(MigrationState *s)
3021 {
3022 qemu_savevm_send_postcopy_resume(s->to_dst_file);
3023
3024 while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
3025 qemu_sem_wait(&s->rp_state.rp_sem);
3026 }
3027
3028 if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
3029 return 0;
3030 }
3031
3032 return -1;
3033 }
3034
3035 /* Return zero if success, or <0 for error */
3036 static int postcopy_do_resume(MigrationState *s)
3037 {
3038 int ret;
3039
3040 /*
3041 * Call all the resume_prepare() hooks, so that modules can be
3042 * ready for the migration resume.
3043 */
3044 ret = qemu_savevm_state_resume_prepare(s);
3045 if (ret) {
3046 error_report("%s: resume_prepare() failure detected: %d",
3047 __func__, ret);
3048 return ret;
3049 }
3050
3051 /*
3052 * Last handshake with destination on the resume (destination will
3053 * switch to postcopy-active afterwards)
3054 */
3055 ret = postcopy_resume_handshake(s);
3056 if (ret) {
3057 error_report("%s: handshake failed: %d", __func__, ret);
3058 return ret;
3059 }
3060
3061 return 0;
3062 }
3063
3064 /*
3065 * We don't return until we are in a safe state to continue current
3066 * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
3067 * MIG_THR_ERR_FATAL if unrecovery failure happened.
3068 */
3069 static MigThrError postcopy_pause(MigrationState *s)
3070 {
3071 assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
3072
3073 while (true) {
3074 QEMUFile *file;
3075
3076 migrate_set_state(&s->state, s->state,
3077 MIGRATION_STATUS_POSTCOPY_PAUSED);
3078
3079 /* Current channel is possibly broken. Release it. */
3080 assert(s->to_dst_file);
3081 qemu_mutex_lock(&s->qemu_file_lock);
3082 file = s->to_dst_file;
3083 s->to_dst_file = NULL;
3084 qemu_mutex_unlock(&s->qemu_file_lock);
3085
3086 qemu_file_shutdown(file);
3087 qemu_fclose(file);
3088
3089 error_report("Detected IO failure for postcopy. "
3090 "Migration paused.");
3091
3092 /*
3093 * We wait until things fixed up. Then someone will setup the
3094 * status back for us.
3095 */
3096 while (s->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
3097 qemu_sem_wait(&s->postcopy_pause_sem);
3098 }
3099
3100 if (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) {
3101 /* Woken up by a recover procedure. Give it a shot */
3102
3103 /*
3104 * Firstly, let's wake up the return path now, with a new
3105 * return path channel.
3106 */
3107 qemu_sem_post(&s->postcopy_pause_rp_sem);
3108
3109 /* Do the resume logic */
3110 if (postcopy_do_resume(s) == 0) {
3111 /* Let's continue! */
3112 trace_postcopy_pause_continued();
3113 return MIG_THR_ERR_RECOVERED;
3114 } else {
3115 /*
3116 * Something wrong happened during the recovery, let's
3117 * pause again. Pause is always better than throwing
3118 * data away.
3119 */
3120 continue;
3121 }
3122 } else {
3123 /* This is not right... Time to quit. */
3124 return MIG_THR_ERR_FATAL;
3125 }
3126 }
3127 }
3128
3129 static MigThrError migration_detect_error(MigrationState *s)
3130 {
3131 int ret;
3132 int state = s->state;
3133 Error *local_error = NULL;
3134
3135 if (state == MIGRATION_STATUS_CANCELLING ||
3136 state == MIGRATION_STATUS_CANCELLED) {
3137 /* End the migration, but don't set the state to failed */
3138 return MIG_THR_ERR_FATAL;
3139 }
3140
3141 /* Try to detect any file errors */
3142 ret = qemu_file_get_error_obj(s->to_dst_file, &local_error);
3143 if (!ret) {
3144 /* Everything is fine */
3145 assert(!local_error);
3146 return MIG_THR_ERR_NONE;
3147 }
3148
3149 if (local_error) {
3150 migrate_set_error(s, local_error);
3151 error_free(local_error);
3152 }
3153
3154 if (state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) {
3155 /*
3156 * For postcopy, we allow the network to be down for a
3157 * while. After that, it can be continued by a
3158 * recovery phase.
3159 */
3160 return postcopy_pause(s);
3161 } else {
3162 /*
3163 * For precopy (or postcopy with error outside IO), we fail
3164 * with no time.
3165 */
3166 migrate_set_state(&s->state, state, MIGRATION_STATUS_FAILED);
3167 trace_migration_thread_file_err();
3168
3169 /* Time to stop the migration, now. */
3170 return MIG_THR_ERR_FATAL;
3171 }
3172 }
3173
3174 /* How many bytes have we transferred since the beginning of the migration */
3175 static uint64_t migration_total_bytes(MigrationState *s)
3176 {
3177 return qemu_ftell(s->to_dst_file) + ram_counters.multifd_bytes;
3178 }
3179
3180 static void migration_calculate_complete(MigrationState *s)
3181 {
3182 uint64_t bytes = migration_total_bytes(s);
3183 int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
3184 int64_t transfer_time;
3185
3186 s->total_time = end_time - s->start_time;
3187 if (!s->downtime) {
3188 /*
3189 * It's still not set, so we are precopy migration. For
3190 * postcopy, downtime is calculated during postcopy_start().
3191 */
3192 s->downtime = end_time - s->downtime_start;
3193 }
3194
3195 transfer_time = s->total_time - s->setup_time;
3196 if (transfer_time) {
3197 s->mbps = ((double) bytes * 8.0) / transfer_time / 1000;
3198 }
3199 }
3200
3201 static void update_iteration_initial_status(MigrationState *s)
3202 {
3203 /*
3204 * Update these three fields at the same time to avoid mismatch info lead
3205 * wrong speed calculation.
3206 */
3207 s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
3208 s->iteration_initial_bytes = migration_total_bytes(s);
3209 s->iteration_initial_pages = ram_get_total_transferred_pages();
3210 }
3211
3212 static void migration_update_counters(MigrationState *s,
3213 int64_t current_time)
3214 {
3215 uint64_t transferred, transferred_pages, time_spent;
3216 uint64_t current_bytes; /* bytes transferred since the beginning */
3217 double bandwidth;
3218
3219 if (current_time < s->iteration_start_time + BUFFER_DELAY) {
3220 return;
3221 }
3222
3223 current_bytes = migration_total_bytes(s);
3224 transferred = current_bytes - s->iteration_initial_bytes;
3225 time_spent = current_time - s->iteration_start_time;
3226 bandwidth = (double)transferred / time_spent;
3227 s->threshold_size = bandwidth * s->parameters.downtime_limit;
3228
3229 s->mbps = (((double) transferred * 8.0) /
3230 ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
3231
3232 transferred_pages = ram_get_total_transferred_pages() -
3233 s->iteration_initial_pages;
3234 s->pages_per_second = (double) transferred_pages /
3235 (((double) time_spent / 1000.0));
3236
3237 /*
3238 * if we haven't sent anything, we don't want to
3239 * recalculate. 10000 is a small enough number for our purposes
3240 */
3241 if (ram_counters.dirty_pages_rate && transferred > 10000) {
3242 s->expected_downtime = ram_counters.remaining / bandwidth;
3243 }
3244
3245 qemu_file_reset_rate_limit(s->to_dst_file);
3246
3247 update_iteration_initial_status(s);
3248
3249 trace_migrate_transferred(transferred, time_spent,
3250 bandwidth, s->threshold_size);
3251 }
3252
3253 /* Migration thread iteration status */
3254 typedef enum {
3255 MIG_ITERATE_RESUME, /* Resume current iteration */
3256 MIG_ITERATE_SKIP, /* Skip current iteration */
3257 MIG_ITERATE_BREAK, /* Break the loop */
3258 } MigIterateState;
3259
3260 /*
3261 * Return true if continue to the next iteration directly, false
3262 * otherwise.
3263 */
3264 static MigIterateState migration_iteration_run(MigrationState *s)
3265 {
3266 uint64_t pending_size, pend_pre, pend_compat, pend_post;
3267 bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE;
3268
3269 qemu_savevm_state_pending(s->to_dst_file, s->threshold_size, &pend_pre,
3270 &pend_compat, &pend_post);
3271 pending_size = pend_pre + pend_compat + pend_post;
3272
3273 trace_migrate_pending(pending_size, s->threshold_size,
3274 pend_pre, pend_compat, pend_post);
3275
3276 if (pending_size && pending_size >= s->threshold_size) {
3277 /* Still a significant amount to transfer */
3278 if (!in_postcopy && pend_pre <= s->threshold_size &&
3279 atomic_read(&s->start_postcopy)) {
3280 if (postcopy_start(s)) {
3281 error_report("%s: postcopy failed to start", __func__);
3282 }
3283 return MIG_ITERATE_SKIP;
3284 }
3285 /* Just another iteration step */
3286 qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
3287 } else {
3288 trace_migration_thread_low_pending(pending_size);
3289 migration_completion(s);
3290 return MIG_ITERATE_BREAK;
3291 }
3292
3293 return MIG_ITERATE_RESUME;
3294 }
3295
3296 static void migration_iteration_finish(MigrationState *s)
3297 {
3298 /* If we enabled cpu throttling for auto-converge, turn it off. */
3299 cpu_throttle_stop();
3300
3301 qemu_mutex_lock_iothread();
3302 switch (s->state) {
3303 case MIGRATION_STATUS_COMPLETED:
3304 migration_calculate_complete(s);
3305 runstate_set(RUN_STATE_POSTMIGRATE);
3306 break;
3307
3308 case MIGRATION_STATUS_ACTIVE:
3309 /*
3310 * We should really assert here, but since it's during
3311 * migration, let's try to reduce the usage of assertions.
3312 */
3313 if (!migrate_colo_enabled()) {
3314 error_report("%s: critical error: calling COLO code without "
3315 "COLO enabled", __func__);
3316 }
3317 migrate_start_colo_process(s);
3318 /*
3319 * Fixme: we will run VM in COLO no matter its old running state.
3320 * After exited COLO, we will keep running.
3321 */
3322 s->vm_was_running = true;
3323 /* Fallthrough */
3324 case MIGRATION_STATUS_FAILED:
3325 case MIGRATION_STATUS_CANCELLED:
3326 case MIGRATION_STATUS_CANCELLING:
3327 if (s->vm_was_running) {
3328 vm_start();
3329 } else {
3330 if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
3331 runstate_set(RUN_STATE_POSTMIGRATE);
3332 }
3333 }
3334 break;
3335
3336 default:
3337 /* Should not reach here, but if so, forgive the VM. */
3338 error_report("%s: Unknown ending state %d", __func__, s->state);
3339 break;
3340 }
3341 migrate_fd_cleanup_schedule(s);
3342 qemu_mutex_unlock_iothread();
3343 }
3344
3345 void migration_make_urgent_request(void)
3346 {
3347 qemu_sem_post(&migrate_get_current()->rate_limit_sem);
3348 }
3349
3350 void migration_consume_urgent_request(void)
3351 {
3352 qemu_sem_wait(&migrate_get_current()->rate_limit_sem);
3353 }
3354
3355 /* Returns true if the rate limiting was broken by an urgent request */
3356 bool migration_rate_limit(void)
3357 {
3358 int64_t now = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
3359 MigrationState *s = migrate_get_current();
3360
3361 bool urgent = false;
3362 migration_update_counters(s, now);
3363 if (qemu_file_rate_limit(s->to_dst_file)) {
3364
3365 if (qemu_file_get_error(s->to_dst_file)) {
3366 return false;
3367 }
3368 /*
3369 * Wait for a delay to do rate limiting OR
3370 * something urgent to post the semaphore.
3371 */
3372 int ms = s->iteration_start_time + BUFFER_DELAY - now;
3373 trace_migration_rate_limit_pre(ms);
3374 if (qemu_sem_timedwait(&s->rate_limit_sem, ms) == 0) {
3375 /*
3376 * We were woken by one or more urgent things but
3377 * the timedwait will have consumed one of them.
3378 * The service routine for the urgent wake will dec
3379 * the semaphore itself for each item it consumes,
3380 * so add this one we just eat back.
3381 */
3382 qemu_sem_post(&s->rate_limit_sem);
3383 urgent = true;
3384 }
3385 trace_migration_rate_limit_post(urgent);
3386 }
3387 return urgent;
3388 }
3389
3390 /*
3391 * Master migration thread on the source VM.
3392 * It drives the migration and pumps the data down the outgoing channel.
3393 */
3394 static void *migration_thread(void *opaque)
3395 {
3396 MigrationState *s = opaque;
3397 int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
3398 MigThrError thr_error;
3399 bool urgent = false;
3400
3401 rcu_register_thread();
3402
3403 object_ref(OBJECT(s));
3404 update_iteration_initial_status(s);
3405
3406 qemu_savevm_state_header(s->to_dst_file);
3407
3408 /*
3409 * If we opened the return path, we need to make sure dst has it
3410 * opened as well.
3411 */
3412 if (s->rp_state.from_dst_file) {
3413 /* Now tell the dest that it should open its end so it can reply */
3414 qemu_savevm_send_open_return_path(s->to_dst_file);
3415
3416 /* And do a ping that will make stuff easier to debug */
3417 qemu_savevm_send_ping(s->to_dst_file, 1);
3418 }
3419
3420 if (migrate_postcopy()) {
3421 /*
3422 * Tell the destination that we *might* want to do postcopy later;
3423 * if the other end can't do postcopy it should fail now, nice and
3424 * early.
3425 */
3426 qemu_savevm_send_postcopy_advise(s->to_dst_file);
3427 }
3428
3429 if (migrate_colo_enabled()) {
3430 /* Notify migration destination that we enable COLO */
3431 qemu_savevm_send_colo_enable(s->to_dst_file);
3432 }
3433
3434 qemu_savevm_state_setup(s->to_dst_file);
3435
3436 if (qemu_savevm_state_guest_unplug_pending()) {
3437 migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
3438 MIGRATION_STATUS_WAIT_UNPLUG);
3439
3440 while (s->state == MIGRATION_STATUS_WAIT_UNPLUG &&
3441 qemu_savevm_state_guest_unplug_pending()) {
3442 qemu_sem_timedwait(&s->wait_unplug_sem, 250);
3443 }
3444
3445 migrate_set_state(&s-></