4 * Copyright IBM, Corp. 2008
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
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.
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"
24 #include "sysemu/runstate.h"
25 #include "sysemu/sysemu.h"
26 #include "sysemu/cpu-throttle.h"
29 #include "migration/global_state.h"
30 #include "migration/misc.h"
31 #include "migration.h"
33 #include "qemu-file-channel.h"
34 #include "qemu-file.h"
35 #include "migration/vmstate.h"
36 #include "block/block.h"
37 #include "qapi/error.h"
38 #include "qapi/clone-visitor.h"
39 #include "qapi/qapi-visit-migration.h"
40 #include "qapi/qapi-visit-sockets.h"
41 #include "qapi/qapi-commands-migration.h"
42 #include "qapi/qapi-events-migration.h"
43 #include "qapi/qmp/qerror.h"
44 #include "qapi/qmp/qnull.h"
47 #include "postcopy-ram.h"
48 #include "qemu/thread.h"
50 #include "exec/target_page.h"
51 #include "io/channel-buffer.h"
52 #include "migration/colo.h"
53 #include "hw/boards.h"
54 #include "hw/qdev-properties.h"
55 #include "hw/qdev-properties-system.h"
56 #include "monitor/monitor.h"
57 #include "net/announce.h"
58 #include "qemu/queue.h"
60 #include "qemu/yank.h"
61 #include "sysemu/cpus.h"
63 #define MAX_THROTTLE (128 << 20) /* Migration transfer speed throttling */
65 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
67 #define BUFFER_DELAY 100
68 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
70 /* Time in milliseconds we are allowed to stop the source,
71 * for sending the last part */
72 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
74 /* Maximum migrate downtime set to 2000 seconds */
75 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000
76 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000)
78 /* Default compression thread count */
79 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
80 /* Default decompression thread count, usually decompression is at
81 * least 4 times as fast as compression.*/
82 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
83 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
84 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
85 /* Define default autoconverge cpu throttle migration parameters */
86 #define DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD 50
87 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
88 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
89 #define DEFAULT_MIGRATE_MAX_CPU_THROTTLE 99
91 /* Migration XBZRLE default cache size */
92 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024)
94 /* The delay time (in ms) between two COLO checkpoints */
95 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100)
96 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
97 #define DEFAULT_MIGRATE_MULTIFD_COMPRESSION MULTIFD_COMPRESSION_NONE
98 /* 0: means nocompress, 1: best speed, ... 9: best compress ratio */
99 #define DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL 1
100 /* 0: means nocompress, 1: best speed, ... 20: best compress ratio */
101 #define DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL 1
103 /* Background transfer rate for postcopy, 0 means unlimited, note
104 * that page requests can still exceed this limit.
106 #define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0
109 * Parameters for self_announce_delay giving a stream of RARP/ARP
110 * packets after migration.
112 #define DEFAULT_MIGRATE_ANNOUNCE_INITIAL 50
113 #define DEFAULT_MIGRATE_ANNOUNCE_MAX 550
114 #define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS 5
115 #define DEFAULT_MIGRATE_ANNOUNCE_STEP 100
117 static NotifierList migration_state_notifiers
=
118 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers
);
120 /* Messages sent on the return path from destination to source */
121 enum mig_rp_message_type
{
122 MIG_RP_MSG_INVALID
= 0, /* Must be 0 */
123 MIG_RP_MSG_SHUT
, /* sibling will not send any more RP messages */
124 MIG_RP_MSG_PONG
, /* Response to a PING; data (seq: be32 ) */
126 MIG_RP_MSG_REQ_PAGES_ID
, /* data (start: be64, len: be32, id: string) */
127 MIG_RP_MSG_REQ_PAGES
, /* data (start: be64, len: be32) */
128 MIG_RP_MSG_RECV_BITMAP
, /* send recved_bitmap back to source */
129 MIG_RP_MSG_RESUME_ACK
, /* tell source that we are ready to resume */
134 /* Migration capabilities set */
135 struct MigrateCapsSet
{
136 int size
; /* Capability set size */
137 MigrationCapability caps
[]; /* Variadic array of capabilities */
139 typedef struct MigrateCapsSet MigrateCapsSet
;
141 /* Define and initialize MigrateCapsSet */
142 #define INITIALIZE_MIGRATE_CAPS_SET(_name, ...) \
143 MigrateCapsSet _name = { \
144 .size = sizeof((int []) { __VA_ARGS__ }) / sizeof(int), \
145 .caps = { __VA_ARGS__ } \
148 /* Background-snapshot compatibility check list */
150 INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot
,
151 MIGRATION_CAPABILITY_POSTCOPY_RAM
,
152 MIGRATION_CAPABILITY_DIRTY_BITMAPS
,
153 MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME
,
154 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE
,
155 MIGRATION_CAPABILITY_RETURN_PATH
,
156 MIGRATION_CAPABILITY_MULTIFD
,
157 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER
,
158 MIGRATION_CAPABILITY_AUTO_CONVERGE
,
159 MIGRATION_CAPABILITY_RELEASE_RAM
,
160 MIGRATION_CAPABILITY_RDMA_PIN_ALL
,
161 MIGRATION_CAPABILITY_COMPRESS
,
162 MIGRATION_CAPABILITY_XBZRLE
,
163 MIGRATION_CAPABILITY_X_COLO
,
164 MIGRATION_CAPABILITY_VALIDATE_UUID
);
166 /* When we add fault tolerance, we could have several
167 migrations at once. For now we don't need to add
168 dynamic creation of migration */
170 static MigrationState
*current_migration
;
171 static MigrationIncomingState
*current_incoming
;
173 static GSList
*migration_blockers
;
175 static bool migration_object_check(MigrationState
*ms
, Error
**errp
);
176 static int migration_maybe_pause(MigrationState
*s
,
177 int *current_active_state
,
179 static void migrate_fd_cancel(MigrationState
*s
);
181 static gint
page_request_addr_cmp(gconstpointer ap
, gconstpointer bp
)
183 uintptr_t a
= (uintptr_t) ap
, b
= (uintptr_t) bp
;
185 return (a
> b
) - (a
< b
);
188 void migration_object_init(void)
192 /* This can only be called once. */
193 assert(!current_migration
);
194 current_migration
= MIGRATION_OBJ(object_new(TYPE_MIGRATION
));
197 * Init the migrate incoming object as well no matter whether
198 * we'll use it or not.
200 assert(!current_incoming
);
201 current_incoming
= g_new0(MigrationIncomingState
, 1);
202 current_incoming
->state
= MIGRATION_STATUS_NONE
;
203 current_incoming
->postcopy_remote_fds
=
204 g_array_new(FALSE
, TRUE
, sizeof(struct PostCopyFD
));
205 qemu_mutex_init(¤t_incoming
->rp_mutex
);
206 qemu_event_init(¤t_incoming
->main_thread_load_event
, false);
207 qemu_sem_init(¤t_incoming
->postcopy_pause_sem_dst
, 0);
208 qemu_sem_init(¤t_incoming
->postcopy_pause_sem_fault
, 0);
209 qemu_mutex_init(¤t_incoming
->page_request_mutex
);
210 current_incoming
->page_requested
= g_tree_new(page_request_addr_cmp
);
212 if (!migration_object_check(current_migration
, &err
)) {
213 error_report_err(err
);
219 dirty_bitmap_mig_init();
222 void migration_cancel(void)
224 migrate_fd_cancel(current_migration
);
227 void migration_shutdown(void)
230 * Cancel the current migration - that will (eventually)
231 * stop the migration using this structure
234 object_unref(OBJECT(current_migration
));
237 * Cancel outgoing migration of dirty bitmaps. It should
238 * at least unref used block nodes.
240 dirty_bitmap_mig_cancel_outgoing();
243 * Cancel incoming migration of dirty bitmaps. Dirty bitmaps
244 * are non-critical data, and their loss never considered as
247 dirty_bitmap_mig_cancel_incoming();
251 MigrationState
*migrate_get_current(void)
253 /* This can only be called after the object created. */
254 assert(current_migration
);
255 return current_migration
;
258 MigrationIncomingState
*migration_incoming_get_current(void)
260 assert(current_incoming
);
261 return current_incoming
;
264 void migration_incoming_state_destroy(void)
266 struct MigrationIncomingState
*mis
= migration_incoming_get_current();
268 if (mis
->to_src_file
) {
269 /* Tell source that we are done */
270 migrate_send_rp_shut(mis
, qemu_file_get_error(mis
->from_src_file
) != 0);
271 qemu_fclose(mis
->to_src_file
);
272 mis
->to_src_file
= NULL
;
275 if (mis
->from_src_file
) {
276 qemu_fclose(mis
->from_src_file
);
277 mis
->from_src_file
= NULL
;
279 if (mis
->postcopy_remote_fds
) {
280 g_array_free(mis
->postcopy_remote_fds
, TRUE
);
281 mis
->postcopy_remote_fds
= NULL
;
284 qemu_event_reset(&mis
->main_thread_load_event
);
286 if (mis
->page_requested
) {
287 g_tree_destroy(mis
->page_requested
);
288 mis
->page_requested
= NULL
;
291 if (mis
->socket_address_list
) {
292 qapi_free_SocketAddressList(mis
->socket_address_list
);
293 mis
->socket_address_list
= NULL
;
296 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
299 static void migrate_generate_event(int new_state
)
301 if (migrate_use_events()) {
302 qapi_event_send_migration(new_state
);
306 static bool migrate_late_block_activate(void)
310 s
= migrate_get_current();
312 return s
->enabled_capabilities
[
313 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE
];
317 * Send a message on the return channel back to the source
320 static int migrate_send_rp_message(MigrationIncomingState
*mis
,
321 enum mig_rp_message_type message_type
,
322 uint16_t len
, void *data
)
326 trace_migrate_send_rp_message((int)message_type
, len
);
327 QEMU_LOCK_GUARD(&mis
->rp_mutex
);
330 * It's possible that the file handle got lost due to network
333 if (!mis
->to_src_file
) {
338 qemu_put_be16(mis
->to_src_file
, (unsigned int)message_type
);
339 qemu_put_be16(mis
->to_src_file
, len
);
340 qemu_put_buffer(mis
->to_src_file
, data
, len
);
341 qemu_fflush(mis
->to_src_file
);
343 /* It's possible that qemu file got error during sending */
344 ret
= qemu_file_get_error(mis
->to_src_file
);
349 /* Request one page from the source VM at the given start address.
350 * rb: the RAMBlock to request the page in
351 * Start: Address offset within the RB
352 * Len: Length in bytes required - must be a multiple of pagesize
354 int migrate_send_rp_message_req_pages(MigrationIncomingState
*mis
,
355 RAMBlock
*rb
, ram_addr_t start
)
357 uint8_t bufc
[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
358 size_t msglen
= 12; /* start + len */
359 size_t len
= qemu_ram_pagesize(rb
);
360 enum mig_rp_message_type msg_type
;
364 *(uint64_t *)bufc
= cpu_to_be64((uint64_t)start
);
365 *(uint32_t *)(bufc
+ 8) = cpu_to_be32((uint32_t)len
);
368 * We maintain the last ramblock that we requested for page. Note that we
369 * don't need locking because this function will only be called within the
370 * postcopy ram fault thread.
372 if (rb
!= mis
->last_rb
) {
375 rbname
= qemu_ram_get_idstr(rb
);
376 rbname_len
= strlen(rbname
);
378 assert(rbname_len
< 256);
380 bufc
[msglen
++] = rbname_len
;
381 memcpy(bufc
+ msglen
, rbname
, rbname_len
);
382 msglen
+= rbname_len
;
383 msg_type
= MIG_RP_MSG_REQ_PAGES_ID
;
385 msg_type
= MIG_RP_MSG_REQ_PAGES
;
388 return migrate_send_rp_message(mis
, msg_type
, msglen
, bufc
);
391 int migrate_send_rp_req_pages(MigrationIncomingState
*mis
,
392 RAMBlock
*rb
, ram_addr_t start
, uint64_t haddr
)
394 void *aligned
= (void *)(uintptr_t)(haddr
& (-qemu_ram_pagesize(rb
)));
395 bool received
= false;
397 WITH_QEMU_LOCK_GUARD(&mis
->page_request_mutex
) {
398 received
= ramblock_recv_bitmap_test_byte_offset(rb
, start
);
399 if (!received
&& !g_tree_lookup(mis
->page_requested
, aligned
)) {
401 * The page has not been received, and it's not yet in the page
402 * request list. Queue it. Set the value of element to 1, so that
403 * things like g_tree_lookup() will return TRUE (1) when found.
405 g_tree_insert(mis
->page_requested
, aligned
, (gpointer
)1);
406 mis
->page_requested_count
++;
407 trace_postcopy_page_req_add(aligned
, mis
->page_requested_count
);
412 * If the page is there, skip sending the message. We don't even need the
413 * lock because as long as the page arrived, it'll be there forever.
419 return migrate_send_rp_message_req_pages(mis
, rb
, start
);
422 static bool migration_colo_enabled
;
423 bool migration_incoming_colo_enabled(void)
425 return migration_colo_enabled
;
428 void migration_incoming_disable_colo(void)
430 ram_block_discard_disable(false);
431 migration_colo_enabled
= false;
434 int migration_incoming_enable_colo(void)
436 if (ram_block_discard_disable(true)) {
437 error_report("COLO: cannot disable RAM discard");
440 migration_colo_enabled
= true;
444 void migrate_add_address(SocketAddress
*address
)
446 MigrationIncomingState
*mis
= migration_incoming_get_current();
448 QAPI_LIST_PREPEND(mis
->socket_address_list
,
449 QAPI_CLONE(SocketAddress
, address
));
452 static void qemu_start_incoming_migration(const char *uri
, Error
**errp
)
454 const char *p
= NULL
;
456 if (!yank_register_instance(MIGRATION_YANK_INSTANCE
, errp
)) {
460 qapi_event_send_migration(MIGRATION_STATUS_SETUP
);
461 if (strstart(uri
, "tcp:", &p
) ||
462 strstart(uri
, "unix:", NULL
) ||
463 strstart(uri
, "vsock:", NULL
)) {
464 socket_start_incoming_migration(p
? p
: uri
, errp
);
466 } else if (strstart(uri
, "rdma:", &p
)) {
467 rdma_start_incoming_migration(p
, errp
);
469 } else if (strstart(uri
, "exec:", &p
)) {
470 exec_start_incoming_migration(p
, errp
);
471 } else if (strstart(uri
, "fd:", &p
)) {
472 fd_start_incoming_migration(p
, errp
);
474 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
475 error_setg(errp
, "unknown migration protocol: %s", uri
);
479 static void process_incoming_migration_bh(void *opaque
)
481 Error
*local_err
= NULL
;
482 MigrationIncomingState
*mis
= opaque
;
484 /* If capability late_block_activate is set:
485 * Only fire up the block code now if we're going to restart the
486 * VM, else 'cont' will do it.
487 * This causes file locking to happen; so we don't want it to happen
488 * unless we really are starting the VM.
490 if (!migrate_late_block_activate() ||
491 (autostart
&& (!global_state_received() ||
492 global_state_get_runstate() == RUN_STATE_RUNNING
))) {
493 /* Make sure all file formats flush their mutable metadata.
494 * If we get an error here, just don't restart the VM yet. */
495 bdrv_invalidate_cache_all(&local_err
);
497 error_report_err(local_err
);
504 * This must happen after all error conditions are dealt with and
505 * we're sure the VM is going to be running on this host.
507 qemu_announce_self(&mis
->announce_timer
, migrate_announce_params());
509 if (multifd_load_cleanup(&local_err
) != 0) {
510 error_report_err(local_err
);
513 /* If global state section was not received or we are in running
514 state, we need to obey autostart. Any other state is set with
517 dirty_bitmap_mig_before_vm_start();
519 if (!global_state_received() ||
520 global_state_get_runstate() == RUN_STATE_RUNNING
) {
524 runstate_set(RUN_STATE_PAUSED
);
526 } else if (migration_incoming_colo_enabled()) {
527 migration_incoming_disable_colo();
530 runstate_set(global_state_get_runstate());
533 * This must happen after any state changes since as soon as an external
534 * observer sees this event they might start to prod at the VM assuming
537 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
538 MIGRATION_STATUS_COMPLETED
);
539 qemu_bh_delete(mis
->bh
);
540 migration_incoming_state_destroy();
543 static void process_incoming_migration_co(void *opaque
)
545 MigrationIncomingState
*mis
= migration_incoming_get_current();
548 Error
*local_err
= NULL
;
550 assert(mis
->from_src_file
);
551 mis
->migration_incoming_co
= qemu_coroutine_self();
552 mis
->largest_page_size
= qemu_ram_pagesize_largest();
553 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
554 migrate_set_state(&mis
->state
, MIGRATION_STATUS_NONE
,
555 MIGRATION_STATUS_ACTIVE
);
556 ret
= qemu_loadvm_state(mis
->from_src_file
);
558 ps
= postcopy_state_get();
559 trace_process_incoming_migration_co_end(ret
, ps
);
560 if (ps
!= POSTCOPY_INCOMING_NONE
) {
561 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
563 * Where a migration had postcopy enabled (and thus went to advise)
564 * but managed to complete within the precopy period, we can use
567 postcopy_ram_incoming_cleanup(mis
);
568 } else if (ret
>= 0) {
570 * Postcopy was started, cleanup should happen at the end of the
573 trace_process_incoming_migration_co_postcopy_end_main();
576 /* Else if something went wrong then just fall out of the normal exit */
579 /* we get COLO info, and know if we are in COLO mode */
580 if (!ret
&& migration_incoming_colo_enabled()) {
581 /* Make sure all file formats flush their mutable metadata */
582 bdrv_invalidate_cache_all(&local_err
);
584 error_report_err(local_err
);
588 qemu_thread_create(&mis
->colo_incoming_thread
, "COLO incoming",
589 colo_process_incoming_thread
, mis
, QEMU_THREAD_JOINABLE
);
590 mis
->have_colo_incoming_thread
= true;
591 qemu_coroutine_yield();
593 /* Wait checkpoint incoming thread exit before free resource */
594 qemu_thread_join(&mis
->colo_incoming_thread
);
595 /* We hold the global iothread lock, so it is safe here */
596 colo_release_ram_cache();
600 error_report("load of migration failed: %s", strerror(-ret
));
603 mis
->bh
= qemu_bh_new(process_incoming_migration_bh
, mis
);
604 qemu_bh_schedule(mis
->bh
);
605 mis
->migration_incoming_co
= NULL
;
609 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
610 MIGRATION_STATUS_FAILED
);
611 qemu_fclose(mis
->from_src_file
);
612 if (multifd_load_cleanup(&local_err
) != 0) {
613 error_report_err(local_err
);
619 * @migration_incoming_setup: Setup incoming migration
621 * Returns 0 for no error or 1 for error
623 * @f: file for main migration channel
624 * @errp: where to put errors
626 static int migration_incoming_setup(QEMUFile
*f
, Error
**errp
)
628 MigrationIncomingState
*mis
= migration_incoming_get_current();
629 Error
*local_err
= NULL
;
631 if (multifd_load_setup(&local_err
) != 0) {
632 /* We haven't been able to create multifd threads
633 nothing better to do */
634 error_report_err(local_err
);
638 if (!mis
->from_src_file
) {
639 mis
->from_src_file
= f
;
641 qemu_file_set_blocking(f
, false);
645 void migration_incoming_process(void)
647 Coroutine
*co
= qemu_coroutine_create(process_incoming_migration_co
, NULL
);
648 qemu_coroutine_enter(co
);
651 /* Returns true if recovered from a paused migration, otherwise false */
652 static bool postcopy_try_recover(QEMUFile
*f
)
654 MigrationIncomingState
*mis
= migration_incoming_get_current();
656 if (mis
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
657 /* Resumed from a paused postcopy migration */
659 mis
->from_src_file
= f
;
660 /* Postcopy has standalone thread to do vm load */
661 qemu_file_set_blocking(f
, true);
663 /* Re-configure the return path */
664 mis
->to_src_file
= qemu_file_get_return_path(f
);
666 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_PAUSED
,
667 MIGRATION_STATUS_POSTCOPY_RECOVER
);
670 * Here, we only wake up the main loading thread (while the
671 * fault thread will still be waiting), so that we can receive
672 * commands from source now, and answer it if needed. The
673 * fault thread will be woken up afterwards until we are sure
674 * that source is ready to reply to page requests.
676 qemu_sem_post(&mis
->postcopy_pause_sem_dst
);
683 void migration_fd_process_incoming(QEMUFile
*f
, Error
**errp
)
685 Error
*local_err
= NULL
;
687 if (postcopy_try_recover(f
)) {
691 if (migration_incoming_setup(f
, &local_err
)) {
692 error_propagate(errp
, local_err
);
695 migration_incoming_process();
698 void migration_ioc_process_incoming(QIOChannel
*ioc
, Error
**errp
)
700 MigrationIncomingState
*mis
= migration_incoming_get_current();
701 Error
*local_err
= NULL
;
702 bool start_migration
;
704 if (!mis
->from_src_file
) {
705 /* The first connection (multifd may have multiple) */
706 QEMUFile
*f
= qemu_fopen_channel_input(ioc
);
708 /* If it's a recovery, we're done */
709 if (postcopy_try_recover(f
)) {
713 if (migration_incoming_setup(f
, &local_err
)) {
714 error_propagate(errp
, local_err
);
719 * Common migration only needs one channel, so we can start
720 * right now. Multifd needs more than one channel, we wait.
722 start_migration
= !migrate_use_multifd();
724 /* Multiple connections */
725 assert(migrate_use_multifd());
726 start_migration
= multifd_recv_new_channel(ioc
, &local_err
);
728 error_propagate(errp
, local_err
);
733 if (start_migration
) {
734 migration_incoming_process();
739 * @migration_has_all_channels: We have received all channels that we need
741 * Returns true when we have got connections to all the channels that
742 * we need for migration.
744 bool migration_has_all_channels(void)
746 MigrationIncomingState
*mis
= migration_incoming_get_current();
749 all_channels
= multifd_recv_all_channels_created();
751 return all_channels
&& mis
->from_src_file
!= NULL
;
755 * Send a 'SHUT' message on the return channel with the given value
756 * to indicate that we've finished with the RP. Non-0 value indicates
759 void migrate_send_rp_shut(MigrationIncomingState
*mis
,
764 buf
= cpu_to_be32(value
);
765 migrate_send_rp_message(mis
, MIG_RP_MSG_SHUT
, sizeof(buf
), &buf
);
769 * Send a 'PONG' message on the return channel with the given value
770 * (normally in response to a 'PING')
772 void migrate_send_rp_pong(MigrationIncomingState
*mis
,
777 buf
= cpu_to_be32(value
);
778 migrate_send_rp_message(mis
, MIG_RP_MSG_PONG
, sizeof(buf
), &buf
);
781 void migrate_send_rp_recv_bitmap(MigrationIncomingState
*mis
,
789 * First, we send the header part. It contains only the len of
790 * idstr, and the idstr itself.
792 len
= strlen(block_name
);
794 memcpy(buf
+ 1, block_name
, len
);
796 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_RECOVER
) {
797 error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
802 migrate_send_rp_message(mis
, MIG_RP_MSG_RECV_BITMAP
, len
+ 1, buf
);
805 * Next, we dump the received bitmap to the stream.
807 * TODO: currently we are safe since we are the only one that is
808 * using the to_src_file handle (fault thread is still paused),
809 * and it's ok even not taking the mutex. However the best way is
810 * to take the lock before sending the message header, and release
811 * the lock after sending the bitmap.
813 qemu_mutex_lock(&mis
->rp_mutex
);
814 res
= ramblock_recv_bitmap_send(mis
->to_src_file
, block_name
);
815 qemu_mutex_unlock(&mis
->rp_mutex
);
817 trace_migrate_send_rp_recv_bitmap(block_name
, res
);
820 void migrate_send_rp_resume_ack(MigrationIncomingState
*mis
, uint32_t value
)
824 buf
= cpu_to_be32(value
);
825 migrate_send_rp_message(mis
, MIG_RP_MSG_RESUME_ACK
, sizeof(buf
), &buf
);
828 MigrationCapabilityStatusList
*qmp_query_migrate_capabilities(Error
**errp
)
830 MigrationCapabilityStatusList
*head
= NULL
, **tail
= &head
;
831 MigrationCapabilityStatus
*caps
;
832 MigrationState
*s
= migrate_get_current();
835 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
836 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
837 if (i
== MIGRATION_CAPABILITY_BLOCK
) {
841 caps
= g_malloc0(sizeof(*caps
));
842 caps
->capability
= i
;
843 caps
->state
= s
->enabled_capabilities
[i
];
844 QAPI_LIST_APPEND(tail
, caps
);
850 MigrationParameters
*qmp_query_migrate_parameters(Error
**errp
)
852 MigrationParameters
*params
;
853 MigrationState
*s
= migrate_get_current();
855 /* TODO use QAPI_CLONE() instead of duplicating it inline */
856 params
= g_malloc0(sizeof(*params
));
857 params
->has_compress_level
= true;
858 params
->compress_level
= s
->parameters
.compress_level
;
859 params
->has_compress_threads
= true;
860 params
->compress_threads
= s
->parameters
.compress_threads
;
861 params
->has_compress_wait_thread
= true;
862 params
->compress_wait_thread
= s
->parameters
.compress_wait_thread
;
863 params
->has_decompress_threads
= true;
864 params
->decompress_threads
= s
->parameters
.decompress_threads
;
865 params
->has_throttle_trigger_threshold
= true;
866 params
->throttle_trigger_threshold
= s
->parameters
.throttle_trigger_threshold
;
867 params
->has_cpu_throttle_initial
= true;
868 params
->cpu_throttle_initial
= s
->parameters
.cpu_throttle_initial
;
869 params
->has_cpu_throttle_increment
= true;
870 params
->cpu_throttle_increment
= s
->parameters
.cpu_throttle_increment
;
871 params
->has_cpu_throttle_tailslow
= true;
872 params
->cpu_throttle_tailslow
= s
->parameters
.cpu_throttle_tailslow
;
873 params
->has_tls_creds
= true;
874 params
->tls_creds
= g_strdup(s
->parameters
.tls_creds
);
875 params
->has_tls_hostname
= true;
876 params
->tls_hostname
= g_strdup(s
->parameters
.tls_hostname
);
877 params
->has_tls_authz
= true;
878 params
->tls_authz
= g_strdup(s
->parameters
.tls_authz
?
879 s
->parameters
.tls_authz
: "");
880 params
->has_max_bandwidth
= true;
881 params
->max_bandwidth
= s
->parameters
.max_bandwidth
;
882 params
->has_downtime_limit
= true;
883 params
->downtime_limit
= s
->parameters
.downtime_limit
;
884 params
->has_x_checkpoint_delay
= true;
885 params
->x_checkpoint_delay
= s
->parameters
.x_checkpoint_delay
;
886 params
->has_block_incremental
= true;
887 params
->block_incremental
= s
->parameters
.block_incremental
;
888 params
->has_multifd_channels
= true;
889 params
->multifd_channels
= s
->parameters
.multifd_channels
;
890 params
->has_multifd_compression
= true;
891 params
->multifd_compression
= s
->parameters
.multifd_compression
;
892 params
->has_multifd_zlib_level
= true;
893 params
->multifd_zlib_level
= s
->parameters
.multifd_zlib_level
;
894 params
->has_multifd_zstd_level
= true;
895 params
->multifd_zstd_level
= s
->parameters
.multifd_zstd_level
;
896 params
->has_xbzrle_cache_size
= true;
897 params
->xbzrle_cache_size
= s
->parameters
.xbzrle_cache_size
;
898 params
->has_max_postcopy_bandwidth
= true;
899 params
->max_postcopy_bandwidth
= s
->parameters
.max_postcopy_bandwidth
;
900 params
->has_max_cpu_throttle
= true;
901 params
->max_cpu_throttle
= s
->parameters
.max_cpu_throttle
;
902 params
->has_announce_initial
= true;
903 params
->announce_initial
= s
->parameters
.announce_initial
;
904 params
->has_announce_max
= true;
905 params
->announce_max
= s
->parameters
.announce_max
;
906 params
->has_announce_rounds
= true;
907 params
->announce_rounds
= s
->parameters
.announce_rounds
;
908 params
->has_announce_step
= true;
909 params
->announce_step
= s
->parameters
.announce_step
;
911 if (s
->parameters
.has_block_bitmap_mapping
) {
912 params
->has_block_bitmap_mapping
= true;
913 params
->block_bitmap_mapping
=
914 QAPI_CLONE(BitmapMigrationNodeAliasList
,
915 s
->parameters
.block_bitmap_mapping
);
921 AnnounceParameters
*migrate_announce_params(void)
923 static AnnounceParameters ap
;
925 MigrationState
*s
= migrate_get_current();
927 ap
.initial
= s
->parameters
.announce_initial
;
928 ap
.max
= s
->parameters
.announce_max
;
929 ap
.rounds
= s
->parameters
.announce_rounds
;
930 ap
.step
= s
->parameters
.announce_step
;
936 * Return true if we're already in the middle of a migration
937 * (i.e. any of the active or setup states)
939 bool migration_is_setup_or_active(int state
)
942 case MIGRATION_STATUS_ACTIVE
:
943 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
944 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
945 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
946 case MIGRATION_STATUS_SETUP
:
947 case MIGRATION_STATUS_PRE_SWITCHOVER
:
948 case MIGRATION_STATUS_DEVICE
:
949 case MIGRATION_STATUS_WAIT_UNPLUG
:
950 case MIGRATION_STATUS_COLO
:
959 bool migration_is_running(int state
)
962 case MIGRATION_STATUS_ACTIVE
:
963 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
964 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
965 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
966 case MIGRATION_STATUS_SETUP
:
967 case MIGRATION_STATUS_PRE_SWITCHOVER
:
968 case MIGRATION_STATUS_DEVICE
:
969 case MIGRATION_STATUS_WAIT_UNPLUG
:
970 case MIGRATION_STATUS_CANCELLING
:
979 static void populate_time_info(MigrationInfo
*info
, MigrationState
*s
)
981 info
->has_status
= true;
982 info
->has_setup_time
= true;
983 info
->setup_time
= s
->setup_time
;
984 if (s
->state
== MIGRATION_STATUS_COMPLETED
) {
985 info
->has_total_time
= true;
986 info
->total_time
= s
->total_time
;
987 info
->has_downtime
= true;
988 info
->downtime
= s
->downtime
;
990 info
->has_total_time
= true;
991 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) -
993 info
->has_expected_downtime
= true;
994 info
->expected_downtime
= s
->expected_downtime
;
998 static void populate_ram_info(MigrationInfo
*info
, MigrationState
*s
)
1000 info
->has_ram
= true;
1001 info
->ram
= g_malloc0(sizeof(*info
->ram
));
1002 info
->ram
->transferred
= ram_counters
.transferred
;
1003 info
->ram
->total
= ram_bytes_total();
1004 info
->ram
->duplicate
= ram_counters
.duplicate
;
1005 /* legacy value. It is not used anymore */
1006 info
->ram
->skipped
= 0;
1007 info
->ram
->normal
= ram_counters
.normal
;
1008 info
->ram
->normal_bytes
= ram_counters
.normal
*
1009 qemu_target_page_size();
1010 info
->ram
->mbps
= s
->mbps
;
1011 info
->ram
->dirty_sync_count
= ram_counters
.dirty_sync_count
;
1012 info
->ram
->postcopy_requests
= ram_counters
.postcopy_requests
;
1013 info
->ram
->page_size
= qemu_target_page_size();
1014 info
->ram
->multifd_bytes
= ram_counters
.multifd_bytes
;
1015 info
->ram
->pages_per_second
= s
->pages_per_second
;
1017 if (migrate_use_xbzrle()) {
1018 info
->has_xbzrle_cache
= true;
1019 info
->xbzrle_cache
= g_malloc0(sizeof(*info
->xbzrle_cache
));
1020 info
->xbzrle_cache
->cache_size
= migrate_xbzrle_cache_size();
1021 info
->xbzrle_cache
->bytes
= xbzrle_counters
.bytes
;
1022 info
->xbzrle_cache
->pages
= xbzrle_counters
.pages
;
1023 info
->xbzrle_cache
->cache_miss
= xbzrle_counters
.cache_miss
;
1024 info
->xbzrle_cache
->cache_miss_rate
= xbzrle_counters
.cache_miss_rate
;
1025 info
->xbzrle_cache
->encoding_rate
= xbzrle_counters
.encoding_rate
;
1026 info
->xbzrle_cache
->overflow
= xbzrle_counters
.overflow
;
1029 if (migrate_use_compression()) {
1030 info
->has_compression
= true;
1031 info
->compression
= g_malloc0(sizeof(*info
->compression
));
1032 info
->compression
->pages
= compression_counters
.pages
;
1033 info
->compression
->busy
= compression_counters
.busy
;
1034 info
->compression
->busy_rate
= compression_counters
.busy_rate
;
1035 info
->compression
->compressed_size
=
1036 compression_counters
.compressed_size
;
1037 info
->compression
->compression_rate
=
1038 compression_counters
.compression_rate
;
1041 if (cpu_throttle_active()) {
1042 info
->has_cpu_throttle_percentage
= true;
1043 info
->cpu_throttle_percentage
= cpu_throttle_get_percentage();
1046 if (s
->state
!= MIGRATION_STATUS_COMPLETED
) {
1047 info
->ram
->remaining
= ram_bytes_remaining();
1048 info
->ram
->dirty_pages_rate
= ram_counters
.dirty_pages_rate
;
1052 static void populate_disk_info(MigrationInfo
*info
)
1054 if (blk_mig_active()) {
1055 info
->has_disk
= true;
1056 info
->disk
= g_malloc0(sizeof(*info
->disk
));
1057 info
->disk
->transferred
= blk_mig_bytes_transferred();
1058 info
->disk
->remaining
= blk_mig_bytes_remaining();
1059 info
->disk
->total
= blk_mig_bytes_total();
1063 static void fill_source_migration_info(MigrationInfo
*info
)
1065 MigrationState
*s
= migrate_get_current();
1066 GSList
*cur_blocker
= migration_blockers
;
1068 info
->blocked_reasons
= NULL
;
1071 * There are two types of reasons a migration might be blocked;
1072 * a) devices marked in VMState as non-migratable, and
1073 * b) Explicit migration blockers
1074 * We need to add both of them here.
1076 qemu_savevm_non_migratable_list(&info
->blocked_reasons
);
1078 while (cur_blocker
) {
1079 QAPI_LIST_PREPEND(info
->blocked_reasons
,
1080 g_strdup(error_get_pretty(cur_blocker
->data
)));
1081 cur_blocker
= g_slist_next(cur_blocker
);
1083 info
->has_blocked_reasons
= info
->blocked_reasons
!= NULL
;
1086 case MIGRATION_STATUS_NONE
:
1087 /* no migration has happened ever */
1088 /* do not overwrite destination migration status */
1090 case MIGRATION_STATUS_SETUP
:
1091 info
->has_status
= true;
1092 info
->has_total_time
= false;
1094 case MIGRATION_STATUS_ACTIVE
:
1095 case MIGRATION_STATUS_CANCELLING
:
1096 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1097 case MIGRATION_STATUS_PRE_SWITCHOVER
:
1098 case MIGRATION_STATUS_DEVICE
:
1099 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1100 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1101 /* TODO add some postcopy stats */
1102 populate_time_info(info
, s
);
1103 populate_ram_info(info
, s
);
1104 populate_disk_info(info
);
1105 populate_vfio_info(info
);
1107 case MIGRATION_STATUS_COLO
:
1108 info
->has_status
= true;
1109 /* TODO: display COLO specific information (checkpoint info etc.) */
1111 case MIGRATION_STATUS_COMPLETED
:
1112 populate_time_info(info
, s
);
1113 populate_ram_info(info
, s
);
1114 populate_vfio_info(info
);
1116 case MIGRATION_STATUS_FAILED
:
1117 info
->has_status
= true;
1119 info
->has_error_desc
= true;
1120 info
->error_desc
= g_strdup(error_get_pretty(s
->error
));
1123 case MIGRATION_STATUS_CANCELLED
:
1124 info
->has_status
= true;
1126 case MIGRATION_STATUS_WAIT_UNPLUG
:
1127 info
->has_status
= true;
1130 info
->status
= s
->state
;
1133 typedef enum WriteTrackingSupport
{
1134 WT_SUPPORT_UNKNOWN
= 0,
1136 WT_SUPPORT_AVAILABLE
,
1137 WT_SUPPORT_COMPATIBLE
1138 } WriteTrackingSupport
;
1141 WriteTrackingSupport
migrate_query_write_tracking(void)
1143 /* Check if kernel supports required UFFD features */
1144 if (!ram_write_tracking_available()) {
1145 return WT_SUPPORT_ABSENT
;
1148 * Check if current memory configuration is
1149 * compatible with required UFFD features.
1151 if (!ram_write_tracking_compatible()) {
1152 return WT_SUPPORT_AVAILABLE
;
1155 return WT_SUPPORT_COMPATIBLE
;
1159 * @migration_caps_check - check capability validity
1161 * @cap_list: old capability list, array of bool
1162 * @params: new capabilities to be applied soon
1163 * @errp: set *errp if the check failed, with reason
1165 * Returns true if check passed, otherwise false.
1167 static bool migrate_caps_check(bool *cap_list
,
1168 MigrationCapabilityStatusList
*params
,
1171 MigrationCapabilityStatusList
*cap
;
1172 bool old_postcopy_cap
;
1173 MigrationIncomingState
*mis
= migration_incoming_get_current();
1175 old_postcopy_cap
= cap_list
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
1177 for (cap
= params
; cap
; cap
= cap
->next
) {
1178 cap_list
[cap
->value
->capability
] = cap
->value
->state
;
1181 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
1182 if (cap_list
[MIGRATION_CAPABILITY_BLOCK
]) {
1183 error_setg(errp
, "QEMU compiled without old-style (blk/-b, inc/-i) "
1185 error_append_hint(errp
, "Use drive_mirror+NBD instead.\n");
1190 #ifndef CONFIG_REPLICATION
1191 if (cap_list
[MIGRATION_CAPABILITY_X_COLO
]) {
1192 error_setg(errp
, "QEMU compiled without replication module"
1193 " can't enable COLO");
1194 error_append_hint(errp
, "Please enable replication before COLO.\n");
1199 if (cap_list
[MIGRATION_CAPABILITY_POSTCOPY_RAM
]) {
1200 /* This check is reasonably expensive, so only when it's being
1201 * set the first time, also it's only the destination that needs
1204 if (!old_postcopy_cap
&& runstate_check(RUN_STATE_INMIGRATE
) &&
1205 !postcopy_ram_supported_by_host(mis
)) {
1206 /* postcopy_ram_supported_by_host will have emitted a more
1209 error_setg(errp
, "Postcopy is not supported");
1213 if (cap_list
[MIGRATION_CAPABILITY_X_IGNORE_SHARED
]) {
1214 error_setg(errp
, "Postcopy is not compatible with ignore-shared");
1219 if (cap_list
[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
]) {
1220 WriteTrackingSupport wt_support
;
1223 * Check if 'background-snapshot' capability is supported by
1224 * host kernel and compatible with guest memory configuration.
1226 wt_support
= migrate_query_write_tracking();
1227 if (wt_support
< WT_SUPPORT_AVAILABLE
) {
1228 error_setg(errp
, "Background-snapshot is not supported by host kernel");
1231 if (wt_support
< WT_SUPPORT_COMPATIBLE
) {
1232 error_setg(errp
, "Background-snapshot is not compatible "
1233 "with guest memory configuration");
1238 * Check if there are any migration capabilities
1239 * incompatible with 'background-snapshot'.
1241 for (idx
= 0; idx
< check_caps_background_snapshot
.size
; idx
++) {
1242 int incomp_cap
= check_caps_background_snapshot
.caps
[idx
];
1243 if (cap_list
[incomp_cap
]) {
1245 "Background-snapshot is not compatible with %s",
1246 MigrationCapability_str(incomp_cap
));
1255 static void fill_destination_migration_info(MigrationInfo
*info
)
1257 MigrationIncomingState
*mis
= migration_incoming_get_current();
1259 if (mis
->socket_address_list
) {
1260 info
->has_socket_address
= true;
1261 info
->socket_address
=
1262 QAPI_CLONE(SocketAddressList
, mis
->socket_address_list
);
1265 switch (mis
->state
) {
1266 case MIGRATION_STATUS_NONE
:
1268 case MIGRATION_STATUS_SETUP
:
1269 case MIGRATION_STATUS_CANCELLING
:
1270 case MIGRATION_STATUS_CANCELLED
:
1271 case MIGRATION_STATUS_ACTIVE
:
1272 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1273 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1274 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1275 case MIGRATION_STATUS_FAILED
:
1276 case MIGRATION_STATUS_COLO
:
1277 info
->has_status
= true;
1279 case MIGRATION_STATUS_COMPLETED
:
1280 info
->has_status
= true;
1281 fill_destination_postcopy_migration_info(info
);
1284 info
->status
= mis
->state
;
1287 MigrationInfo
*qmp_query_migrate(Error
**errp
)
1289 MigrationInfo
*info
= g_malloc0(sizeof(*info
));
1291 fill_destination_migration_info(info
);
1292 fill_source_migration_info(info
);
1297 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList
*params
,
1300 MigrationState
*s
= migrate_get_current();
1301 MigrationCapabilityStatusList
*cap
;
1302 bool cap_list
[MIGRATION_CAPABILITY__MAX
];
1304 if (migration_is_running(s
->state
)) {
1305 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
1309 memcpy(cap_list
, s
->enabled_capabilities
, sizeof(cap_list
));
1310 if (!migrate_caps_check(cap_list
, params
, errp
)) {
1314 for (cap
= params
; cap
; cap
= cap
->next
) {
1315 s
->enabled_capabilities
[cap
->value
->capability
] = cap
->value
->state
;
1320 * Check whether the parameters are valid. Error will be put into errp
1321 * (if provided). Return true if valid, otherwise false.
1323 static bool migrate_params_check(MigrationParameters
*params
, Error
**errp
)
1325 if (params
->has_compress_level
&&
1326 (params
->compress_level
> 9)) {
1327 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "compress_level",
1328 "a value between 0 and 9");
1332 if (params
->has_compress_threads
&& (params
->compress_threads
< 1)) {
1333 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1335 "a value between 1 and 255");
1339 if (params
->has_decompress_threads
&& (params
->decompress_threads
< 1)) {
1340 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1341 "decompress_threads",
1342 "a value between 1 and 255");
1346 if (params
->has_throttle_trigger_threshold
&&
1347 (params
->throttle_trigger_threshold
< 1 ||
1348 params
->throttle_trigger_threshold
> 100)) {
1349 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1350 "throttle_trigger_threshold",
1351 "an integer in the range of 1 to 100");
1355 if (params
->has_cpu_throttle_initial
&&
1356 (params
->cpu_throttle_initial
< 1 ||
1357 params
->cpu_throttle_initial
> 99)) {
1358 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1359 "cpu_throttle_initial",
1360 "an integer in the range of 1 to 99");
1364 if (params
->has_cpu_throttle_increment
&&
1365 (params
->cpu_throttle_increment
< 1 ||
1366 params
->cpu_throttle_increment
> 99)) {
1367 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1368 "cpu_throttle_increment",
1369 "an integer in the range of 1 to 99");
1373 if (params
->has_max_bandwidth
&& (params
->max_bandwidth
> SIZE_MAX
)) {
1374 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1376 "an integer in the range of 0 to "stringify(SIZE_MAX
)
1381 if (params
->has_downtime_limit
&&
1382 (params
->downtime_limit
> MAX_MIGRATE_DOWNTIME
)) {
1383 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1385 "an integer in the range of 0 to "
1386 stringify(MAX_MIGRATE_DOWNTIME
)" ms");
1390 /* x_checkpoint_delay is now always positive */
1392 if (params
->has_multifd_channels
&& (params
->multifd_channels
< 1)) {
1393 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1395 "a value between 1 and 255");
1399 if (params
->has_multifd_zlib_level
&&
1400 (params
->multifd_zlib_level
> 9)) {
1401 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "multifd_zlib_level",
1402 "a value between 0 and 9");
1406 if (params
->has_multifd_zstd_level
&&
1407 (params
->multifd_zstd_level
> 20)) {
1408 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "multifd_zstd_level",
1409 "a value between 0 and 20");
1413 if (params
->has_xbzrle_cache_size
&&
1414 (params
->xbzrle_cache_size
< qemu_target_page_size() ||
1415 !is_power_of_2(params
->xbzrle_cache_size
))) {
1416 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1417 "xbzrle_cache_size",
1418 "a power of two no less than the target page size");
1422 if (params
->has_max_cpu_throttle
&&
1423 (params
->max_cpu_throttle
< params
->cpu_throttle_initial
||
1424 params
->max_cpu_throttle
> 99)) {
1425 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1427 "an integer in the range of cpu_throttle_initial to 99");
1431 if (params
->has_announce_initial
&&
1432 params
->announce_initial
> 100000) {
1433 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1435 "a value between 0 and 100000");
1438 if (params
->has_announce_max
&&
1439 params
->announce_max
> 100000) {
1440 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1442 "a value between 0 and 100000");
1445 if (params
->has_announce_rounds
&&
1446 params
->announce_rounds
> 1000) {
1447 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1449 "a value between 0 and 1000");
1452 if (params
->has_announce_step
&&
1453 (params
->announce_step
< 1 ||
1454 params
->announce_step
> 10000)) {
1455 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1457 "a value between 0 and 10000");
1461 if (params
->has_block_bitmap_mapping
&&
1462 !check_dirty_bitmap_mig_alias_map(params
->block_bitmap_mapping
, errp
)) {
1463 error_prepend(errp
, "Invalid mapping given for block-bitmap-mapping: ");
1470 static void migrate_params_test_apply(MigrateSetParameters
*params
,
1471 MigrationParameters
*dest
)
1473 *dest
= migrate_get_current()->parameters
;
1475 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1477 if (params
->has_compress_level
) {
1478 dest
->compress_level
= params
->compress_level
;
1481 if (params
->has_compress_threads
) {
1482 dest
->compress_threads
= params
->compress_threads
;
1485 if (params
->has_compress_wait_thread
) {
1486 dest
->compress_wait_thread
= params
->compress_wait_thread
;
1489 if (params
->has_decompress_threads
) {
1490 dest
->decompress_threads
= params
->decompress_threads
;
1493 if (params
->has_throttle_trigger_threshold
) {
1494 dest
->throttle_trigger_threshold
= params
->throttle_trigger_threshold
;
1497 if (params
->has_cpu_throttle_initial
) {
1498 dest
->cpu_throttle_initial
= params
->cpu_throttle_initial
;
1501 if (params
->has_cpu_throttle_increment
) {
1502 dest
->cpu_throttle_increment
= params
->cpu_throttle_increment
;
1505 if (params
->has_cpu_throttle_tailslow
) {
1506 dest
->cpu_throttle_tailslow
= params
->cpu_throttle_tailslow
;
1509 if (params
->has_tls_creds
) {
1510 assert(params
->tls_creds
->type
== QTYPE_QSTRING
);
1511 dest
->tls_creds
= params
->tls_creds
->u
.s
;
1514 if (params
->has_tls_hostname
) {
1515 assert(params
->tls_hostname
->type
== QTYPE_QSTRING
);
1516 dest
->tls_hostname
= params
->tls_hostname
->u
.s
;
1519 if (params
->has_max_bandwidth
) {
1520 dest
->max_bandwidth
= params
->max_bandwidth
;
1523 if (params
->has_downtime_limit
) {
1524 dest
->downtime_limit
= params
->downtime_limit
;
1527 if (params
->has_x_checkpoint_delay
) {
1528 dest
->x_checkpoint_delay
= params
->x_checkpoint_delay
;
1531 if (params
->has_block_incremental
) {
1532 dest
->block_incremental
= params
->block_incremental
;
1534 if (params
->has_multifd_channels
) {
1535 dest
->multifd_channels
= params
->multifd_channels
;
1537 if (params
->has_multifd_compression
) {
1538 dest
->multifd_compression
= params
->multifd_compression
;
1540 if (params
->has_xbzrle_cache_size
) {
1541 dest
->xbzrle_cache_size
= params
->xbzrle_cache_size
;
1543 if (params
->has_max_postcopy_bandwidth
) {
1544 dest
->max_postcopy_bandwidth
= params
->max_postcopy_bandwidth
;
1546 if (params
->has_max_cpu_throttle
) {
1547 dest
->max_cpu_throttle
= params
->max_cpu_throttle
;
1549 if (params
->has_announce_initial
) {
1550 dest
->announce_initial
= params
->announce_initial
;
1552 if (params
->has_announce_max
) {
1553 dest
->announce_max
= params
->announce_max
;
1555 if (params
->has_announce_rounds
) {
1556 dest
->announce_rounds
= params
->announce_rounds
;
1558 if (params
->has_announce_step
) {
1559 dest
->announce_step
= params
->announce_step
;
1562 if (params
->has_block_bitmap_mapping
) {
1563 dest
->has_block_bitmap_mapping
= true;
1564 dest
->block_bitmap_mapping
= params
->block_bitmap_mapping
;
1568 static void migrate_params_apply(MigrateSetParameters
*params
, Error
**errp
)
1570 MigrationState
*s
= migrate_get_current();
1572 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1574 if (params
->has_compress_level
) {
1575 s
->parameters
.compress_level
= params
->compress_level
;
1578 if (params
->has_compress_threads
) {
1579 s
->parameters
.compress_threads
= params
->compress_threads
;
1582 if (params
->has_compress_wait_thread
) {
1583 s
->parameters
.compress_wait_thread
= params
->compress_wait_thread
;
1586 if (params
->has_decompress_threads
) {
1587 s
->parameters
.decompress_threads
= params
->decompress_threads
;
1590 if (params
->has_throttle_trigger_threshold
) {
1591 s
->parameters
.throttle_trigger_threshold
= params
->throttle_trigger_threshold
;
1594 if (params
->has_cpu_throttle_initial
) {
1595 s
->parameters
.cpu_throttle_initial
= params
->cpu_throttle_initial
;
1598 if (params
->has_cpu_throttle_increment
) {
1599 s
->parameters
.cpu_throttle_increment
= params
->cpu_throttle_increment
;
1602 if (params
->has_cpu_throttle_tailslow
) {
1603 s
->parameters
.cpu_throttle_tailslow
= params
->cpu_throttle_tailslow
;
1606 if (params
->has_tls_creds
) {
1607 g_free(s
->parameters
.tls_creds
);
1608 assert(params
->tls_creds
->type
== QTYPE_QSTRING
);
1609 s
->parameters
.tls_creds
= g_strdup(params
->tls_creds
->u
.s
);
1612 if (params
->has_tls_hostname
) {
1613 g_free(s
->parameters
.tls_hostname
);
1614 assert(params
->tls_hostname
->type
== QTYPE_QSTRING
);
1615 s
->parameters
.tls_hostname
= g_strdup(params
->tls_hostname
->u
.s
);
1618 if (params
->has_tls_authz
) {
1619 g_free(s
->parameters
.tls_authz
);
1620 assert(params
->tls_authz
->type
== QTYPE_QSTRING
);
1621 s
->parameters
.tls_authz
= g_strdup(params
->tls_authz
->u
.s
);
1624 if (params
->has_max_bandwidth
) {
1625 s
->parameters
.max_bandwidth
= params
->max_bandwidth
;
1626 if (s
->to_dst_file
&& !migration_in_postcopy()) {
1627 qemu_file_set_rate_limit(s
->to_dst_file
,
1628 s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
);
1632 if (params
->has_downtime_limit
) {
1633 s
->parameters
.downtime_limit
= params
->downtime_limit
;
1636 if (params
->has_x_checkpoint_delay
) {
1637 s
->parameters
.x_checkpoint_delay
= params
->x_checkpoint_delay
;
1638 if (migration_in_colo_state()) {
1639 colo_checkpoint_notify(s
);
1643 if (params
->has_block_incremental
) {
1644 s
->parameters
.block_incremental
= params
->block_incremental
;
1646 if (params
->has_multifd_channels
) {
1647 s
->parameters
.multifd_channels
= params
->multifd_channels
;
1649 if (params
->has_multifd_compression
) {
1650 s
->parameters
.multifd_compression
= params
->multifd_compression
;
1652 if (params
->has_xbzrle_cache_size
) {
1653 s
->parameters
.xbzrle_cache_size
= params
->xbzrle_cache_size
;
1654 xbzrle_cache_resize(params
->xbzrle_cache_size
, errp
);
1656 if (params
->has_max_postcopy_bandwidth
) {
1657 s
->parameters
.max_postcopy_bandwidth
= params
->max_postcopy_bandwidth
;
1658 if (s
->to_dst_file
&& migration_in_postcopy()) {
1659 qemu_file_set_rate_limit(s
->to_dst_file
,
1660 s
->parameters
.max_postcopy_bandwidth
/ XFER_LIMIT_RATIO
);
1663 if (params
->has_max_cpu_throttle
) {
1664 s
->parameters
.max_cpu_throttle
= params
->max_cpu_throttle
;
1666 if (params
->has_announce_initial
) {
1667 s
->parameters
.announce_initial
= params
->announce_initial
;
1669 if (params
->has_announce_max
) {
1670 s
->parameters
.announce_max
= params
->announce_max
;
1672 if (params
->has_announce_rounds
) {
1673 s
->parameters
.announce_rounds
= params
->announce_rounds
;
1675 if (params
->has_announce_step
) {
1676 s
->parameters
.announce_step
= params
->announce_step
;
1679 if (params
->has_block_bitmap_mapping
) {
1680 qapi_free_BitmapMigrationNodeAliasList(
1681 s
->parameters
.block_bitmap_mapping
);
1683 s
->parameters
.has_block_bitmap_mapping
= true;
1684 s
->parameters
.block_bitmap_mapping
=
1685 QAPI_CLONE(BitmapMigrationNodeAliasList
,
1686 params
->block_bitmap_mapping
);
1690 void qmp_migrate_set_parameters(MigrateSetParameters
*params
, Error
**errp
)
1692 MigrationParameters tmp
;
1694 /* TODO Rewrite "" to null instead */
1695 if (params
->has_tls_creds
1696 && params
->tls_creds
->type
== QTYPE_QNULL
) {
1697 qobject_unref(params
->tls_creds
->u
.n
);
1698 params
->tls_creds
->type
= QTYPE_QSTRING
;
1699 params
->tls_creds
->u
.s
= strdup("");
1701 /* TODO Rewrite "" to null instead */
1702 if (params
->has_tls_hostname
1703 && params
->tls_hostname
->type
== QTYPE_QNULL
) {
1704 qobject_unref(params
->tls_hostname
->u
.n
);
1705 params
->tls_hostname
->type
= QTYPE_QSTRING
;
1706 params
->tls_hostname
->u
.s
= strdup("");
1709 migrate_params_test_apply(params
, &tmp
);
1711 if (!migrate_params_check(&tmp
, errp
)) {
1712 /* Invalid parameter */
1716 migrate_params_apply(params
, errp
);
1720 void qmp_migrate_start_postcopy(Error
**errp
)
1722 MigrationState
*s
= migrate_get_current();
1724 if (!migrate_postcopy()) {
1725 error_setg(errp
, "Enable postcopy with migrate_set_capability before"
1726 " the start of migration");
1730 if (s
->state
== MIGRATION_STATUS_NONE
) {
1731 error_setg(errp
, "Postcopy must be started after migration has been"
1736 * we don't error if migration has finished since that would be racy
1737 * with issuing this command.
1739 qatomic_set(&s
->start_postcopy
, true);
1742 /* shared migration helpers */
1744 void migrate_set_state(int *state
, int old_state
, int new_state
)
1746 assert(new_state
< MIGRATION_STATUS__MAX
);
1747 if (qatomic_cmpxchg(state
, old_state
, new_state
) == old_state
) {
1748 trace_migrate_set_state(MigrationStatus_str(new_state
));
1749 migrate_generate_event(new_state
);
1753 static MigrationCapabilityStatus
*migrate_cap_add(MigrationCapability index
,
1756 MigrationCapabilityStatus
*cap
;
1758 cap
= g_new0(MigrationCapabilityStatus
, 1);
1759 cap
->capability
= index
;
1765 void migrate_set_block_enabled(bool value
, Error
**errp
)
1767 MigrationCapabilityStatusList
*cap
= NULL
;
1769 QAPI_LIST_PREPEND(cap
, migrate_cap_add(MIGRATION_CAPABILITY_BLOCK
, value
));
1770 qmp_migrate_set_capabilities(cap
, errp
);
1771 qapi_free_MigrationCapabilityStatusList(cap
);
1774 static void migrate_set_block_incremental(MigrationState
*s
, bool value
)
1776 s
->parameters
.block_incremental
= value
;
1779 static void block_cleanup_parameters(MigrationState
*s
)
1781 if (s
->must_remove_block_options
) {
1782 /* setting to false can never fail */
1783 migrate_set_block_enabled(false, &error_abort
);
1784 migrate_set_block_incremental(s
, false);
1785 s
->must_remove_block_options
= false;
1789 static void migrate_fd_cleanup(MigrationState
*s
)
1791 qemu_bh_delete(s
->cleanup_bh
);
1792 s
->cleanup_bh
= NULL
;
1794 qemu_savevm_state_cleanup();
1796 if (s
->to_dst_file
) {
1799 trace_migrate_fd_cleanup();
1800 qemu_mutex_unlock_iothread();
1801 if (s
->migration_thread_running
) {
1802 qemu_thread_join(&s
->thread
);
1803 s
->migration_thread_running
= false;
1805 qemu_mutex_lock_iothread();
1807 multifd_save_cleanup();
1808 qemu_mutex_lock(&s
->qemu_file_lock
);
1809 tmp
= s
->to_dst_file
;
1810 s
->to_dst_file
= NULL
;
1811 qemu_mutex_unlock(&s
->qemu_file_lock
);
1813 * Close the file handle without the lock to make sure the
1814 * critical section won't block for long.
1819 assert(!migration_is_active(s
));
1821 if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
1822 migrate_set_state(&s
->state
, MIGRATION_STATUS_CANCELLING
,
1823 MIGRATION_STATUS_CANCELLED
);
1827 /* It is used on info migrate. We can't free it */
1828 error_report_err(error_copy(s
->error
));
1830 notifier_list_notify(&migration_state_notifiers
, s
);
1831 block_cleanup_parameters(s
);
1832 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
1835 static void migrate_fd_cleanup_schedule(MigrationState
*s
)
1838 * Ref the state for bh, because it may be called when
1839 * there're already no other refs
1841 object_ref(OBJECT(s
));
1842 qemu_bh_schedule(s
->cleanup_bh
);
1845 static void migrate_fd_cleanup_bh(void *opaque
)
1847 MigrationState
*s
= opaque
;
1848 migrate_fd_cleanup(s
);
1849 object_unref(OBJECT(s
));
1852 void migrate_set_error(MigrationState
*s
, const Error
*error
)
1854 QEMU_LOCK_GUARD(&s
->error_mutex
);
1856 s
->error
= error_copy(error
);
1860 void migrate_fd_error(MigrationState
*s
, const Error
*error
)
1862 trace_migrate_fd_error(error_get_pretty(error
));
1863 assert(s
->to_dst_file
== NULL
);
1864 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1865 MIGRATION_STATUS_FAILED
);
1866 migrate_set_error(s
, error
);
1869 static void migrate_fd_cancel(MigrationState
*s
)
1872 QEMUFile
*f
= migrate_get_current()->to_dst_file
;
1873 trace_migrate_fd_cancel();
1875 if (s
->rp_state
.from_dst_file
) {
1876 /* shutdown the rp socket, so causing the rp thread to shutdown */
1877 qemu_file_shutdown(s
->rp_state
.from_dst_file
);
1881 old_state
= s
->state
;
1882 if (!migration_is_running(old_state
)) {
1885 /* If the migration is paused, kick it out of the pause */
1886 if (old_state
== MIGRATION_STATUS_PRE_SWITCHOVER
) {
1887 qemu_sem_post(&s
->pause_sem
);
1889 migrate_set_state(&s
->state
, old_state
, MIGRATION_STATUS_CANCELLING
);
1890 } while (s
->state
!= MIGRATION_STATUS_CANCELLING
);
1893 * If we're unlucky the migration code might be stuck somewhere in a
1894 * send/write while the network has failed and is waiting to timeout;
1895 * if we've got shutdown(2) available then we can force it to quit.
1896 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1897 * called in a bh, so there is no race against this cancel.
1899 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& f
) {
1900 qemu_file_shutdown(f
);
1902 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& s
->block_inactive
) {
1903 Error
*local_err
= NULL
;
1905 bdrv_invalidate_cache_all(&local_err
);
1907 error_report_err(local_err
);
1909 s
->block_inactive
= false;
1914 void add_migration_state_change_notifier(Notifier
*notify
)
1916 notifier_list_add(&migration_state_notifiers
, notify
);
1919 void remove_migration_state_change_notifier(Notifier
*notify
)
1921 notifier_remove(notify
);
1924 bool migration_in_setup(MigrationState
*s
)
1926 return s
->state
== MIGRATION_STATUS_SETUP
;
1929 bool migration_has_finished(MigrationState
*s
)
1931 return s
->state
== MIGRATION_STATUS_COMPLETED
;
1934 bool migration_has_failed(MigrationState
*s
)
1936 return (s
->state
== MIGRATION_STATUS_CANCELLED
||
1937 s
->state
== MIGRATION_STATUS_FAILED
);
1940 bool migration_in_postcopy(void)
1942 MigrationState
*s
= migrate_get_current();
1945 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1946 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1947 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1954 bool migration_in_postcopy_after_devices(MigrationState
*s
)
1956 return migration_in_postcopy() && s
->postcopy_after_devices
;
1959 bool migration_in_incoming_postcopy(void)
1961 PostcopyState ps
= postcopy_state_get();
1963 return ps
>= POSTCOPY_INCOMING_DISCARD
&& ps
< POSTCOPY_INCOMING_END
;
1966 bool migration_in_bg_snapshot(void)
1968 MigrationState
*s
= migrate_get_current();
1970 return migrate_background_snapshot() &&
1971 migration_is_setup_or_active(s
->state
);
1974 bool migration_is_idle(void)
1976 MigrationState
*s
= current_migration
;
1983 case MIGRATION_STATUS_NONE
:
1984 case MIGRATION_STATUS_CANCELLED
:
1985 case MIGRATION_STATUS_COMPLETED
:
1986 case MIGRATION_STATUS_FAILED
:
1988 case MIGRATION_STATUS_SETUP
:
1989 case MIGRATION_STATUS_CANCELLING
:
1990 case MIGRATION_STATUS_ACTIVE
:
1991 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1992 case MIGRATION_STATUS_COLO
:
1993 case MIGRATION_STATUS_PRE_SWITCHOVER
:
1994 case MIGRATION_STATUS_DEVICE
:
1995 case MIGRATION_STATUS_WAIT_UNPLUG
:
1997 case MIGRATION_STATUS__MAX
:
1998 g_assert_not_reached();
2004 bool migration_is_active(MigrationState
*s
)
2006 return (s
->state
== MIGRATION_STATUS_ACTIVE
||
2007 s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2010 void migrate_init(MigrationState
*s
)
2013 * Reinitialise all migration state, except
2014 * parameters/capabilities that the user set, and
2019 s
->to_dst_file
= NULL
;
2020 s
->state
= MIGRATION_STATUS_NONE
;
2021 s
->rp_state
.from_dst_file
= NULL
;
2022 s
->rp_state
.error
= false;
2024 s
->pages_per_second
= 0.0;
2026 s
->expected_downtime
= 0;
2028 s
->start_postcopy
= false;
2029 s
->postcopy_after_devices
= false;
2030 s
->migration_thread_running
= false;
2031 error_free(s
->error
);
2035 migrate_set_state(&s
->state
, MIGRATION_STATUS_NONE
, MIGRATION_STATUS_SETUP
);
2037 s
->start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
2039 s
->vm_was_running
= false;
2040 s
->iteration_initial_bytes
= 0;
2041 s
->threshold_size
= 0;
2044 int migrate_add_blocker(Error
*reason
, Error
**errp
)
2046 if (only_migratable
) {
2047 error_propagate_prepend(errp
, error_copy(reason
),
2048 "disallowing migration blocker "
2049 "(--only-migratable) for: ");
2053 if (migration_is_idle()) {
2054 migration_blockers
= g_slist_prepend(migration_blockers
, reason
);
2058 error_propagate_prepend(errp
, error_copy(reason
),
2059 "disallowing migration blocker "
2060 "(migration in progress) for: ");
2064 void migrate_del_blocker(Error
*reason
)
2066 migration_blockers
= g_slist_remove(migration_blockers
, reason
);
2069 void qmp_migrate_incoming(const char *uri
, Error
**errp
)
2071 Error
*local_err
= NULL
;
2072 static bool once
= true;
2075 error_setg(errp
, "The incoming migration has already been started");
2078 if (!runstate_check(RUN_STATE_INMIGRATE
)) {
2079 error_setg(errp
, "'-incoming' was not specified on the command line");
2083 qemu_start_incoming_migration(uri
, &local_err
);
2086 error_propagate(errp
, local_err
);
2093 void qmp_migrate_recover(const char *uri
, Error
**errp
)
2095 MigrationIncomingState
*mis
= migration_incoming_get_current();
2097 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2098 error_setg(errp
, "Migrate recover can only be run "
2099 "when postcopy is paused.");
2103 if (qatomic_cmpxchg(&mis
->postcopy_recover_triggered
,
2104 false, true) == true) {
2105 error_setg(errp
, "Migrate recovery is triggered already");
2110 * Note that this call will never start a real migration; it will
2111 * only re-setup the migration stream and poke existing migration
2112 * to continue using that newly established channel.
2114 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2115 qemu_start_incoming_migration(uri
, errp
);
2118 void qmp_migrate_pause(Error
**errp
)
2120 MigrationState
*ms
= migrate_get_current();
2121 MigrationIncomingState
*mis
= migration_incoming_get_current();
2124 if (ms
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
2125 /* Source side, during postcopy */
2126 qemu_mutex_lock(&ms
->qemu_file_lock
);
2127 ret
= qemu_file_shutdown(ms
->to_dst_file
);
2128 qemu_mutex_unlock(&ms
->qemu_file_lock
);
2130 error_setg(errp
, "Failed to pause source migration");
2135 if (mis
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
2136 ret
= qemu_file_shutdown(mis
->from_src_file
);
2138 error_setg(errp
, "Failed to pause destination migration");
2143 error_setg(errp
, "migrate-pause is currently only supported "
2144 "during postcopy-active state");
2147 bool migration_is_blocked(Error
**errp
)
2149 if (qemu_savevm_state_blocked(errp
)) {
2153 if (migration_blockers
) {
2154 error_propagate(errp
, error_copy(migration_blockers
->data
));
2161 /* Returns true if continue to migrate, or false if error detected */
2162 static bool migrate_prepare(MigrationState
*s
, bool blk
, bool blk_inc
,
2163 bool resume
, Error
**errp
)
2165 Error
*local_err
= NULL
;
2168 if (s
->state
!= MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2169 error_setg(errp
, "Cannot resume if there is no "
2170 "paused migration");
2175 * Postcopy recovery won't work well with release-ram
2176 * capability since release-ram will drop the page buffer as
2177 * long as the page is put into the send buffer. So if there
2178 * is a network failure happened, any page buffers that have
2179 * not yet reached the destination VM but have already been
2180 * sent from the source VM will be lost forever. Let's refuse
2181 * the client from resuming such a postcopy migration.
2182 * Luckily release-ram was designed to only be used when src
2183 * and destination VMs are on the same host, so it should be
2186 if (migrate_release_ram()) {
2187 error_setg(errp
, "Postcopy recovery cannot work "
2188 "when release-ram capability is set");
2192 /* This is a resume, skip init status */
2196 if (migration_is_running(s
->state
)) {
2197 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
2201 if (runstate_check(RUN_STATE_INMIGRATE
)) {
2202 error_setg(errp
, "Guest is waiting for an incoming migration");
2206 if (runstate_check(RUN_STATE_POSTMIGRATE
)) {
2207 error_setg(errp
, "Can't migrate the vm that was paused due to "
2208 "previous migration");
2212 if (migration_is_blocked(errp
)) {
2216 if (blk
|| blk_inc
) {
2217 if (migrate_use_block() || migrate_use_block_incremental()) {
2218 error_setg(errp
, "Command options are incompatible with "
2219 "current migration capabilities");
2222 migrate_set_block_enabled(true, &local_err
);
2224 error_propagate(errp
, local_err
);
2227 s
->must_remove_block_options
= true;
2231 migrate_set_block_incremental(s
, true);
2236 * set ram_counters memory to zero for a
2239 memset(&ram_counters
, 0, sizeof(ram_counters
));
2244 void qmp_migrate(const char *uri
, bool has_blk
, bool blk
,
2245 bool has_inc
, bool inc
, bool has_detach
, bool detach
,
2246 bool has_resume
, bool resume
, Error
**errp
)
2248 Error
*local_err
= NULL
;
2249 MigrationState
*s
= migrate_get_current();
2250 const char *p
= NULL
;
2252 if (!migrate_prepare(s
, has_blk
&& blk
, has_inc
&& inc
,
2253 has_resume
&& resume
, errp
)) {
2254 /* Error detected, put into errp */
2258 if (!(has_resume
&& resume
)) {
2259 if (!yank_register_instance(MIGRATION_YANK_INSTANCE
, errp
)) {
2264 if (strstart(uri
, "tcp:", &p
) ||
2265 strstart(uri
, "unix:", NULL
) ||
2266 strstart(uri
, "vsock:", NULL
)) {
2267 socket_start_outgoing_migration(s
, p
? p
: uri
, &local_err
);
2269 } else if (strstart(uri
, "rdma:", &p
)) {
2270 rdma_start_outgoing_migration(s
, p
, &local_err
);
2272 } else if (strstart(uri
, "exec:", &p
)) {
2273 exec_start_outgoing_migration(s
, p
, &local_err
);
2274 } else if (strstart(uri
, "fd:", &p
)) {
2275 fd_start_outgoing_migration(s
, p
, &local_err
);
2277 if (!(has_resume
&& resume
)) {
2278 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2280 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "uri",
2281 "a valid migration protocol");
2282 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
2283 MIGRATION_STATUS_FAILED
);
2284 block_cleanup_parameters(s
);
2289 if (!(has_resume
&& resume
)) {
2290 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2292 migrate_fd_error(s
, local_err
);
2293 error_propagate(errp
, local_err
);
2298 void qmp_migrate_cancel(Error
**errp
)
2303 void qmp_migrate_continue(MigrationStatus state
, Error
**errp
)
2305 MigrationState
*s
= migrate_get_current();
2306 if (s
->state
!= state
) {
2307 error_setg(errp
, "Migration not in expected state: %s",
2308 MigrationStatus_str(s
->state
));
2311 qemu_sem_post(&s
->pause_sem
);
2314 bool migrate_release_ram(void)
2318 s
= migrate_get_current();
2320 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_RELEASE_RAM
];
2323 bool migrate_postcopy_ram(void)
2327 s
= migrate_get_current();
2329 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
2332 bool migrate_postcopy(void)
2334 return migrate_postcopy_ram() || migrate_dirty_bitmaps();
2337 bool migrate_auto_converge(void)
2341 s
= migrate_get_current();
2343 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_AUTO_CONVERGE
];
2346 bool migrate_zero_blocks(void)
2350 s
= migrate_get_current();
2352 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_ZERO_BLOCKS
];
2355 bool migrate_postcopy_blocktime(void)
2359 s
= migrate_get_current();
2361 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME
];
2364 bool migrate_use_compression(void)
2368 s
= migrate_get_current();
2370 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_COMPRESS
];
2373 int migrate_compress_level(void)
2377 s
= migrate_get_current();
2379 return s
->parameters
.compress_level
;
2382 int migrate_compress_threads(void)
2386 s
= migrate_get_current();
2388 return s
->parameters
.compress_threads
;
2391 int migrate_compress_wait_thread(void)
2395 s
= migrate_get_current();
2397 return s
->parameters
.compress_wait_thread
;
2400 int migrate_decompress_threads(void)
2404 s
= migrate_get_current();
2406 return s
->parameters
.decompress_threads
;
2409 bool migrate_dirty_bitmaps(void)
2413 s
= migrate_get_current();
2415 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_DIRTY_BITMAPS
];
2418 bool migrate_ignore_shared(void)
2422 s
= migrate_get_current();
2424 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_IGNORE_SHARED
];
2427 bool migrate_validate_uuid(void)
2431 s
= migrate_get_current();
2433 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_VALIDATE_UUID
];
2436 bool migrate_use_events(void)
2440 s
= migrate_get_current();
2442 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_EVENTS
];
2445 bool migrate_use_multifd(void)
2449 s
= migrate_get_current();
2451 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_MULTIFD
];
2454 bool migrate_pause_before_switchover(void)
2458 s
= migrate_get_current();
2460 return s
->enabled_capabilities
[
2461 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER
];
2464 int migrate_multifd_channels(void)
2468 s
= migrate_get_current();
2470 return s
->parameters
.multifd_channels
;
2473 MultiFDCompression
migrate_multifd_compression(void)
2477 s
= migrate_get_current();
2479 return s
->parameters
.multifd_compression
;
2482 int migrate_multifd_zlib_level(void)
2486 s
= migrate_get_current();
2488 return s
->parameters
.multifd_zlib_level
;
2491 int migrate_multifd_zstd_level(void)
2495 s
= migrate_get_current();
2497 return s
->parameters
.multifd_zstd_level
;
2500 int migrate_use_xbzrle(void)
2504 s
= migrate_get_current();
2506 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_XBZRLE
];
2509 uint64_t migrate_xbzrle_cache_size(void)
2513 s
= migrate_get_current();
2515 return s
->parameters
.xbzrle_cache_size
;
2518 static int64_t migrate_max_postcopy_bandwidth(void)
2522 s
= migrate_get_current();
2524 return s
->parameters
.max_postcopy_bandwidth
;
2527 bool migrate_use_block(void)
2531 s
= migrate_get_current();
2533 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_BLOCK
];
2536 bool migrate_use_return_path(void)
2540 s
= migrate_get_current();
2542 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_RETURN_PATH
];
2545 bool migrate_use_block_incremental(void)
2549 s
= migrate_get_current();
2551 return s
->parameters
.block_incremental
;
2554 bool migrate_background_snapshot(void)
2558 s
= migrate_get_current();
2560 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
];
2563 /* migration thread support */
2565 * Something bad happened to the RP stream, mark an error
2566 * The caller shall print or trace something to indicate why
2568 static void mark_source_rp_bad(MigrationState
*s
)
2570 s
->rp_state
.error
= true;
2573 static struct rp_cmd_args
{
2574 ssize_t len
; /* -1 = variable */
2577 [MIG_RP_MSG_INVALID
] = { .len
= -1, .name
= "INVALID" },
2578 [MIG_RP_MSG_SHUT
] = { .len
= 4, .name
= "SHUT" },
2579 [MIG_RP_MSG_PONG
] = { .len
= 4, .name
= "PONG" },
2580 [MIG_RP_MSG_REQ_PAGES
] = { .len
= 12, .name
= "REQ_PAGES" },
2581 [MIG_RP_MSG_REQ_PAGES_ID
] = { .len
= -1, .name
= "REQ_PAGES_ID" },
2582 [MIG_RP_MSG_RECV_BITMAP
] = { .len
= -1, .name
= "RECV_BITMAP" },
2583 [MIG_RP_MSG_RESUME_ACK
] = { .len
= 4, .name
= "RESUME_ACK" },
2584 [MIG_RP_MSG_MAX
] = { .len
= -1, .name
= "MAX" },
2588 * Process a request for pages received on the return path,
2589 * We're allowed to send more than requested (e.g. to round to our page size)
2590 * and we don't need to send pages that have already been sent.
2592 static void migrate_handle_rp_req_pages(MigrationState
*ms
, const char* rbname
,
2593 ram_addr_t start
, size_t len
)
2595 long our_host_ps
= qemu_real_host_page_size
;
2597 trace_migrate_handle_rp_req_pages(rbname
, start
, len
);
2600 * Since we currently insist on matching page sizes, just sanity check
2601 * we're being asked for whole host pages.
2603 if (start
& (our_host_ps
- 1) ||
2604 (len
& (our_host_ps
- 1))) {
2605 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
2606 " len: %zd", __func__
, start
, len
);
2607 mark_source_rp_bad(ms
);
2611 if (ram_save_queue_pages(rbname
, start
, len
)) {
2612 mark_source_rp_bad(ms
);
2616 /* Return true to retry, false to quit */
2617 static bool postcopy_pause_return_path_thread(MigrationState
*s
)
2619 trace_postcopy_pause_return_path();
2621 qemu_sem_wait(&s
->postcopy_pause_rp_sem
);
2623 trace_postcopy_pause_return_path_continued();
2628 static int migrate_handle_rp_recv_bitmap(MigrationState
*s
, char *block_name
)
2630 RAMBlock
*block
= qemu_ram_block_by_name(block_name
);
2633 error_report("%s: invalid block name '%s'", __func__
, block_name
);
2637 /* Fetch the received bitmap and refresh the dirty bitmap */
2638 return ram_dirty_bitmap_reload(s
, block
);
2641 static int migrate_handle_rp_resume_ack(MigrationState
*s
, uint32_t value
)
2643 trace_source_return_path_thread_resume_ack(value
);
2645 if (value
!= MIGRATION_RESUME_ACK_VALUE
) {
2646 error_report("%s: illegal resume_ack value %"PRIu32
,
2651 /* Now both sides are active. */
2652 migrate_set_state(&s
->state
, MIGRATION_STATUS_POSTCOPY_RECOVER
,
2653 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2655 /* Notify send thread that time to continue send pages */
2656 qemu_sem_post(&s
->rp_state
.rp_sem
);
2662 * Handles messages sent on the return path towards the source VM
2665 static void *source_return_path_thread(void *opaque
)
2667 MigrationState
*ms
= opaque
;
2668 QEMUFile
*rp
= ms
->rp_state
.from_dst_file
;
2669 uint16_t header_len
, header_type
;
2671 uint32_t tmp32
, sibling_error
;
2672 ram_addr_t start
= 0; /* =0 to silence warning */
2673 size_t len
= 0, expected_len
;
2676 trace_source_return_path_thread_entry();
2677 rcu_register_thread();
2680 while (!ms
->rp_state
.error
&& !qemu_file_get_error(rp
) &&
2681 migration_is_setup_or_active(ms
->state
)) {
2682 trace_source_return_path_thread_loop_top();
2683 header_type
= qemu_get_be16(rp
);
2684 header_len
= qemu_get_be16(rp
);
2686 if (qemu_file_get_error(rp
)) {
2687 mark_source_rp_bad(ms
);
2691 if (header_type
>= MIG_RP_MSG_MAX
||
2692 header_type
== MIG_RP_MSG_INVALID
) {
2693 error_report("RP: Received invalid message 0x%04x length 0x%04x",
2694 header_type
, header_len
);
2695 mark_source_rp_bad(ms
);
2699 if ((rp_cmd_args
[header_type
].len
!= -1 &&
2700 header_len
!= rp_cmd_args
[header_type
].len
) ||
2701 header_len
> sizeof(buf
)) {
2702 error_report("RP: Received '%s' message (0x%04x) with"
2703 "incorrect length %d expecting %zu",
2704 rp_cmd_args
[header_type
].name
, header_type
, header_len
,
2705 (size_t)rp_cmd_args
[header_type
].len
);
2706 mark_source_rp_bad(ms
);
2710 /* We know we've got a valid header by this point */
2711 res
= qemu_get_buffer(rp
, buf
, header_len
);
2712 if (res
!= header_len
) {
2713 error_report("RP: Failed reading data for message 0x%04x"
2714 " read %d expected %d",
2715 header_type
, res
, header_len
);
2716 mark_source_rp_bad(ms
);
2720 /* OK, we have the message and the data */
2721 switch (header_type
) {
2722 case MIG_RP_MSG_SHUT
:
2723 sibling_error
= ldl_be_p(buf
);
2724 trace_source_return_path_thread_shut(sibling_error
);
2725 if (sibling_error
) {
2726 error_report("RP: Sibling indicated error %d", sibling_error
);
2727 mark_source_rp_bad(ms
);
2730 * We'll let the main thread deal with closing the RP
2731 * we could do a shutdown(2) on it, but we're the only user
2732 * anyway, so there's nothing gained.
2736 case MIG_RP_MSG_PONG
:
2737 tmp32
= ldl_be_p(buf
);
2738 trace_source_return_path_thread_pong(tmp32
);
2741 case MIG_RP_MSG_REQ_PAGES
:
2742 start
= ldq_be_p(buf
);
2743 len
= ldl_be_p(buf
+ 8);
2744 migrate_handle_rp_req_pages(ms
, NULL
, start
, len
);
2747 case MIG_RP_MSG_REQ_PAGES_ID
:
2748 expected_len
= 12 + 1; /* header + termination */
2750 if (header_len
>= expected_len
) {
2751 start
= ldq_be_p(buf
);
2752 len
= ldl_be_p(buf
+ 8);
2753 /* Now we expect an idstr */
2754 tmp32
= buf
[12]; /* Length of the following idstr */
2755 buf
[13 + tmp32
] = '\0';
2756 expected_len
+= tmp32
;
2758 if (header_len
!= expected_len
) {
2759 error_report("RP: Req_Page_id with length %d expecting %zd",
2760 header_len
, expected_len
);
2761 mark_source_rp_bad(ms
);
2764 migrate_handle_rp_req_pages(ms
, (char *)&buf
[13], start
, len
);
2767 case MIG_RP_MSG_RECV_BITMAP
:
2768 if (header_len
< 1) {
2769 error_report("%s: missing block name", __func__
);
2770 mark_source_rp_bad(ms
);
2773 /* Format: len (1B) + idstr (<255B). This ends the idstr. */
2774 buf
[buf
[0] + 1] = '\0';
2775 if (migrate_handle_rp_recv_bitmap(ms
, (char *)(buf
+ 1))) {
2776 mark_source_rp_bad(ms
);
2781 case MIG_RP_MSG_RESUME_ACK
:
2782 tmp32
= ldl_be_p(buf
);
2783 if (migrate_handle_rp_resume_ack(ms
, tmp32
)) {
2784 mark_source_rp_bad(ms
);
2795 res
= qemu_file_get_error(rp
);
2797 if (res
== -EIO
&& migration_in_postcopy()) {
2799 * Maybe there is something we can do: it looks like a
2800 * network down issue, and we pause for a recovery.
2802 if (postcopy_pause_return_path_thread(ms
)) {
2803 /* Reload rp, reset the rest */
2804 if (rp
!= ms
->rp_state
.from_dst_file
) {
2806 rp
= ms
->rp_state
.from_dst_file
;
2808 ms
->rp_state
.error
= false;
2813 trace_source_return_path_thread_bad_end();
2814 mark_source_rp_bad(ms
);
2817 trace_source_return_path_thread_end();
2818 ms
->rp_state
.from_dst_file
= NULL
;
2820 rcu_unregister_thread();
2824 static int open_return_path_on_source(MigrationState
*ms
,
2828 ms
->rp_state
.from_dst_file
= qemu_file_get_return_path(ms
->to_dst_file
);
2829 if (!ms
->rp_state
.from_dst_file
) {
2833 trace_open_return_path_on_source();
2835 if (!create_thread
) {
2840 qemu_thread_create(&ms
->rp_state
.rp_thread
, "return path",
2841 source_return_path_thread
, ms
, QEMU_THREAD_JOINABLE
);
2843 trace_open_return_path_on_source_continue();
2848 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
2849 static int await_return_path_close_on_source(MigrationState
*ms
)
2852 * If this is a normal exit then the destination will send a SHUT and the
2853 * rp_thread will exit, however if there's an error we need to cause
2856 if (qemu_file_get_error(ms
->to_dst_file
) && ms
->rp_state
.from_dst_file
) {
2858 * shutdown(2), if we have it, will cause it to unblock if it's stuck
2859 * waiting for the destination.
2861 qemu_file_shutdown(ms
->rp_state
.from_dst_file
);
2862 mark_source_rp_bad(ms
);
2864 trace_await_return_path_close_on_source_joining();
2865 qemu_thread_join(&ms
->rp_state
.rp_thread
);
2866 trace_await_return_path_close_on_source_close();
2867 return ms
->rp_state
.error
;
2871 * Switch from normal iteration to postcopy
2872 * Returns non-0 on error
2874 static int postcopy_start(MigrationState
*ms
)
2877 QIOChannelBuffer
*bioc
;
2879 int64_t time_at_stop
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
2880 int64_t bandwidth
= migrate_max_postcopy_bandwidth();
2881 bool restart_block
= false;
2882 int cur_state
= MIGRATION_STATUS_ACTIVE
;
2883 if (!migrate_pause_before_switchover()) {
2884 migrate_set_state(&ms
->state
, MIGRATION_STATUS_ACTIVE
,
2885 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2888 trace_postcopy_start();
2889 qemu_mutex_lock_iothread();
2890 trace_postcopy_start_set_run();
2892 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
2893 global_state_store();
2894 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
2899 ret
= migration_maybe_pause(ms
, &cur_state
,
2900 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2905 ret
= bdrv_inactivate_all();
2909 restart_block
= true;
2912 * Cause any non-postcopiable, but iterative devices to
2913 * send out their final data.
2915 qemu_savevm_state_complete_precopy(ms
->to_dst_file
, true, false);
2918 * in Finish migrate and with the io-lock held everything should
2919 * be quiet, but we've potentially still got dirty pages and we
2920 * need to tell the destination to throw any pages it's already received
2923 if (migrate_postcopy_ram()) {
2924 if (ram_postcopy_send_discard_bitmap(ms
)) {
2925 error_report("postcopy send discard bitmap failed");
2931 * send rest of state - note things that are doing postcopy
2932 * will notice we're in POSTCOPY_ACTIVE and not actually
2933 * wrap their state up here
2935 /* 0 max-postcopy-bandwidth means unlimited */
2937 qemu_file_set_rate_limit(ms
->to_dst_file
, INT64_MAX
);
2939 qemu_file_set_rate_limit(ms
->to_dst_file
, bandwidth
/ XFER_LIMIT_RATIO
);
2941 if (migrate_postcopy_ram()) {
2942 /* Ping just for debugging, helps line traces up */
2943 qemu_savevm_send_ping(ms
->to_dst_file
, 2);
2947 * While loading the device state we may trigger page transfer
2948 * requests and the fd must be free to process those, and thus
2949 * the destination must read the whole device state off the fd before
2950 * it starts processing it. Unfortunately the ad-hoc migration format
2951 * doesn't allow the destination to know the size to read without fully
2952 * parsing it through each devices load-state code (especially the open
2953 * coded devices that use get/put).
2954 * So we wrap the device state up in a package with a length at the start;
2955 * to do this we use a qemu_buf to hold the whole of the device state.
2957 bioc
= qio_channel_buffer_new(4096);
2958 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-postcopy-buffer");
2959 fb
= qemu_fopen_channel_output(QIO_CHANNEL(bioc
));
2960 object_unref(OBJECT(bioc
));
2963 * Make sure the receiver can get incoming pages before we send the rest
2966 qemu_savevm_send_postcopy_listen(fb
);
2968 qemu_savevm_state_complete_precopy(fb
, false, false);
2969 if (migrate_postcopy_ram()) {
2970 qemu_savevm_send_ping(fb
, 3);
2973 qemu_savevm_send_postcopy_run(fb
);
2975 /* <><> end of stuff going into the package */
2977 /* Last point of recovery; as soon as we send the package the destination
2978 * can open devices and potentially start running.
2979 * Lets just check again we've not got any errors.
2981 ret
= qemu_file_get_error(ms
->to_dst_file
);
2983 error_report("postcopy_start: Migration stream errored (pre package)");
2987 restart_block
= false;
2989 /* Now send that blob */
2990 if (qemu_savevm_send_packaged(ms
->to_dst_file
, bioc
->data
, bioc
->usage
)) {
2995 /* Send a notify to give a chance for anything that needs to happen
2996 * at the transition to postcopy and after the device state; in particular
2997 * spice needs to trigger a transition now
2999 ms
->postcopy_after_devices
= true;
3000 notifier_list_notify(&migration_state_notifiers
, ms
);
3002 ms
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - time_at_stop
;
3004 qemu_mutex_unlock_iothread();
3006 if (migrate_postcopy_ram()) {
3008 * Although this ping is just for debug, it could potentially be
3009 * used for getting a better measurement of downtime at the source.
3011 qemu_savevm_send_ping(ms
->to_dst_file
, 4);
3014 if (migrate_release_ram()) {
3015 ram_postcopy_migrated_memory_release(ms
);
3018 ret
= qemu_file_get_error(ms
->to_dst_file
);
3020 error_report("postcopy_start: Migration stream errored");
3021 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
3022 MIGRATION_STATUS_FAILED
);
3030 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
3031 MIGRATION_STATUS_FAILED
);
3032 if (restart_block
) {
3033 /* A failure happened early enough that we know the destination hasn't
3034 * accessed block devices, so we're safe to recover.
3036 Error
*local_err
= NULL
;
3038 bdrv_invalidate_cache_all(&local_err
);
3040 error_report_err(local_err
);
3043 qemu_mutex_unlock_iothread();
3048 * migration_maybe_pause: Pause if required to by
3049 * migrate_pause_before_switchover called with the iothread locked
3050 * Returns: 0 on success
3052 static int migration_maybe_pause(MigrationState
*s
,
3053 int *current_active_state
,
3056 if (!migrate_pause_before_switchover()) {
3060 /* Since leaving this state is not atomic with posting the semaphore
3061 * it's possible that someone could have issued multiple migrate_continue
3062 * and the semaphore is incorrectly positive at this point;
3063 * the docs say it's undefined to reinit a semaphore that's already
3064 * init'd, so use timedwait to eat up any existing posts.
3066 while (qemu_sem_timedwait(&s
->pause_sem
, 1) == 0) {
3067 /* This block intentionally left blank */
3071 * If the migration is cancelled when it is in the completion phase,
3072 * the migration state is set to MIGRATION_STATUS_CANCELLING.
3073 * So we don't need to wait a semaphore, otherwise we would always
3074 * wait for the 'pause_sem' semaphore.
3076 if (s
->state
!= MIGRATION_STATUS_CANCELLING
) {
3077 qemu_mutex_unlock_iothread();
3078 migrate_set_state(&s
->state
, *current_active_state
,
3079 MIGRATION_STATUS_PRE_SWITCHOVER
);
3080 qemu_sem_wait(&s
->pause_sem
);
3081 migrate_set_state(&s
->state
, MIGRATION_STATUS_PRE_SWITCHOVER
,
3083 *current_active_state
= new_state
;
3084 qemu_mutex_lock_iothread();
3087 return s
->state
== new_state
? 0 : -EINVAL
;
3091 * migration_completion: Used by migration_thread when there's not much left.
3092 * The caller 'breaks' the loop when this returns.
3094 * @s: Current migration state
3096 static void migration_completion(MigrationState
*s
)
3099 int current_active_state
= s
->state
;
3101 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
3102 qemu_mutex_lock_iothread();
3103 s
->downtime_start
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3104 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
3105 s
->vm_was_running
= runstate_is_running();
3106 ret
= global_state_store();
3109 bool inactivate
= !migrate_colo_enabled();
3110 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
3112 ret
= migration_maybe_pause(s
, ¤t_active_state
,
3113 MIGRATION_STATUS_DEVICE
);
3116 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
3117 ret
= qemu_savevm_state_complete_precopy(s
->to_dst_file
, false,
3120 if (inactivate
&& ret
>= 0) {
3121 s
->block_inactive
= true;
3124 qemu_mutex_unlock_iothread();
3129 } else if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
3130 trace_migration_completion_postcopy_end();
3132 qemu_savevm_state_complete_postcopy(s
->to_dst_file
);
3133 trace_migration_completion_postcopy_end_after_complete();
3134 } else if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
3139 * If rp was opened we must clean up the thread before
3140 * cleaning everything else up (since if there are no failures
3141 * it will wait for the destination to send it's status in
3144 if (s
->rp_state
.from_dst_file
) {
3146 trace_migration_return_path_end_before();
3147 rp_error
= await_return_path_close_on_source(s
);
3148 trace_migration_return_path_end_after(rp_error
);
3150 goto fail_invalidate
;
3154 if (qemu_file_get_error(s
->to_dst_file
)) {
3155 trace_migration_completion_file_err();
3156 goto fail_invalidate
;
3159 if (!migrate_colo_enabled()) {
3160 migrate_set_state(&s
->state
, current_active_state
,
3161 MIGRATION_STATUS_COMPLETED
);
3167 /* If not doing postcopy, vm_start() will be called: let's regain
3168 * control on images.
3170 if (s
->state
== MIGRATION_STATUS_ACTIVE
||
3171 s
->state
== MIGRATION_STATUS_DEVICE
) {
3172 Error
*local_err
= NULL
;
3174 qemu_mutex_lock_iothread();
3175 bdrv_invalidate_cache_all(&local_err
);
3177 error_report_err(local_err
);
3179 s
->block_inactive
= false;
3181 qemu_mutex_unlock_iothread();
3185 migrate_set_state(&s
->state
, current_active_state
,
3186 MIGRATION_STATUS_FAILED
);
3190 * bg_migration_completion: Used by bg_migration_thread when after all the
3191 * RAM has been saved. The caller 'breaks' the loop when this returns.
3193 * @s: Current migration state
3195 static void bg_migration_completion(MigrationState
*s
)
3197 int current_active_state
= s
->state
;
3200 * Stop tracking RAM writes - un-protect memory, un-register UFFD
3201 * memory ranges, flush kernel wait queues and wake up threads
3202 * waiting for write fault to be resolved.
3204 ram_write_tracking_stop();
3206 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
3208 * By this moment we have RAM content saved into the migration stream.
3209 * The next step is to flush the non-RAM content (device state)
3210 * right after the ram content. The device state has been stored into
3211 * the temporary buffer before RAM saving started.
3213 qemu_put_buffer(s
->to_dst_file
, s
->bioc
->data
, s
->bioc
->usage
);
3214 qemu_fflush(s
->to_dst_file
);
3215 } else if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
3219 if (qemu_file_get_error(s
->to_dst_file
)) {
3220 trace_migration_completion_file_err();
3224 migrate_set_state(&s
->state
, current_active_state
,
3225 MIGRATION_STATUS_COMPLETED
);
3229 migrate_set_state(&s
->state
, current_active_state
,
3230 MIGRATION_STATUS_FAILED
);
3233 bool migrate_colo_enabled(void)
3235 MigrationState
*s
= migrate_get_current();
3236 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_COLO
];
3239 typedef enum MigThrError
{
3240 /* No error detected */
3241 MIG_THR_ERR_NONE
= 0,
3242 /* Detected error, but resumed successfully */
3243 MIG_THR_ERR_RECOVERED
= 1,
3244 /* Detected fatal error, need to exit */
3245 MIG_THR_ERR_FATAL
= 2,
3248 static int postcopy_resume_handshake(MigrationState
*s
)
3250 qemu_savevm_send_postcopy_resume(s
->to_dst_file
);
3252 while (s
->state
== MIGRATION_STATUS_POSTCOPY_RECOVER
) {
3253 qemu_sem_wait(&s
->rp_state
.rp_sem
);
3256 if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
3263 /* Return zero if success, or <0 for error */
3264 static int postcopy_do_resume(MigrationState
*s
)
3269 * Call all the resume_prepare() hooks, so that modules can be
3270 * ready for the migration resume.
3272 ret
= qemu_savevm_state_resume_prepare(s
);
3274 error_report("%s: resume_prepare() failure detected: %d",
3280 * Last handshake with destination on the resume (destination will
3281 * switch to postcopy-active afterwards)
3283 ret
= postcopy_resume_handshake(s
);
3285 error_report("%s: handshake failed: %d", __func__
, ret
);
3293 * We don't return until we are in a safe state to continue current
3294 * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
3295 * MIG_THR_ERR_FATAL if unrecovery failure happened.
3297 static MigThrError
postcopy_pause(MigrationState
*s
)
3299 assert(s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
3304 /* Current channel is possibly broken. Release it. */
3305 assert(s
->to_dst_file
);
3306 qemu_mutex_lock(&s
->qemu_file_lock
);
3307 file
= s
->to_dst_file
;
3308 s
->to_dst_file
= NULL
;
3309 qemu_mutex_unlock(&s
->qemu_file_lock
);
3311 qemu_file_shutdown(file
);
3314 migrate_set_state(&s
->state
, s
->state
,
3315 MIGRATION_STATUS_POSTCOPY_PAUSED
);
3317 error_report("Detected IO failure for postcopy. "
3318 "Migration paused.");
3321 * We wait until things fixed up. Then someone will setup the
3322 * status back for us.
3324 while (s
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
3325 qemu_sem_wait(&s
->postcopy_pause_sem
);
3328 if (s
->state
== MIGRATION_STATUS_POSTCOPY_RECOVER
) {
3329 /* Woken up by a recover procedure. Give it a shot */
3332 * Firstly, let's wake up the return path now, with a new
3333 * return path channel.
3335 qemu_sem_post(&s
->postcopy_pause_rp_sem
);
3337 /* Do the resume logic */
3338 if (postcopy_do_resume(s
) == 0) {
3339 /* Let's continue! */
3340 trace_postcopy_pause_continued();
3341 return MIG_THR_ERR_RECOVERED
;
3344 * Something wrong happened during the recovery, let's
3345 * pause again. Pause is always better than throwing
3351 /* This is not right... Time to quit. */
3352 return MIG_THR_ERR_FATAL
;
3357 static MigThrError
migration_detect_error(MigrationState
*s
)
3360 int state
= s
->state
;
3361 Error
*local_error
= NULL
;
3363 if (state
== MIGRATION_STATUS_CANCELLING
||
3364 state
== MIGRATION_STATUS_CANCELLED
) {
3365 /* End the migration, but don't set the state to failed */
3366 return MIG_THR_ERR_FATAL
;
3369 /* Try to detect any file errors */
3370 ret
= qemu_file_get_error_obj(s
->to_dst_file
, &local_error
);
3372 /* Everything is fine */
3373 assert(!local_error
);
3374 return MIG_THR_ERR_NONE
;
3378 migrate_set_error(s
, local_error
);
3379 error_free(local_error
);
3382 if (state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
&& ret
== -EIO
) {
3384 * For postcopy, we allow the network to be down for a
3385 * while. After that, it can be continued by a
3388 return postcopy_pause(s
);
3391 * For precopy (or postcopy with error outside IO), we fail
3394 migrate_set_state(&s
->state
, state
, MIGRATION_STATUS_FAILED
);
3395 trace_migration_thread_file_err();
3397 /* Time to stop the migration, now. */
3398 return MIG_THR_ERR_FATAL
;
3402 /* How many bytes have we transferred since the beginning of the migration */
3403 static uint64_t migration_total_bytes(MigrationState
*s
)
3405 return qemu_ftell(s
->to_dst_file
) + ram_counters
.multifd_bytes
;
3408 static void migration_calculate_complete(MigrationState
*s
)
3410 uint64_t bytes
= migration_total_bytes(s
);
3411 int64_t end_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3412 int64_t transfer_time
;
3414 s
->total_time
= end_time
- s
->start_time
;
3417 * It's still not set, so we are precopy migration. For
3418 * postcopy, downtime is calculated during postcopy_start().
3420 s
->downtime
= end_time
- s
->downtime_start
;
3423 transfer_time
= s
->total_time
- s
->setup_time
;
3424 if (transfer_time
) {
3425 s
->mbps
= ((double) bytes
* 8.0) / transfer_time
/ 1000;
3429 static void update_iteration_initial_status(MigrationState
*s
)
3432 * Update these three fields at the same time to avoid mismatch info lead
3433 * wrong speed calculation.
3435 s
->iteration_start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3436 s
->iteration_initial_bytes
= migration_total_bytes(s
);
3437 s
->iteration_initial_pages
= ram_get_total_transferred_pages();
3440 static void migration_update_counters(MigrationState
*s
,
3441 int64_t current_time
)
3443 uint64_t transferred
, transferred_pages
, time_spent
;
3444 uint64_t current_bytes
; /* bytes transferred since the beginning */
3447 if (current_time
< s
->iteration_start_time
+ BUFFER_DELAY
) {
3451 current_bytes
= migration_total_bytes(s
);
3452 transferred
= current_bytes
- s
->iteration_initial_bytes
;
3453 time_spent
= current_time
- s
->iteration_start_time
;
3454 bandwidth
= (double)transferred
/ time_spent
;
3455 s
->threshold_size
= bandwidth
* s
->parameters
.downtime_limit
;
3457 s
->mbps
= (((double) transferred
* 8.0) /
3458 ((double) time_spent
/ 1000.0)) / 1000.0 / 1000.0;
3460 transferred_pages
= ram_get_total_transferred_pages() -
3461 s
->iteration_initial_pages
;
3462 s
->pages_per_second
= (double) transferred_pages
/
3463 (((double) time_spent
/ 1000.0));
3466 * if we haven't sent anything, we don't want to
3467 * recalculate. 10000 is a small enough number for our purposes
3469 if (ram_counters
.dirty_pages_rate
&& transferred
> 10000) {
3470 s
->expected_downtime
= ram_counters
.remaining
/ bandwidth
;
3473 qemu_file_reset_rate_limit(s
->to_dst_file
);
3475 update_iteration_initial_status(s
);
3477 trace_migrate_transferred(transferred
, time_spent
,
3478 bandwidth
, s
->threshold_size
);
3481 /* Migration thread iteration status */
3483 MIG_ITERATE_RESUME
, /* Resume current iteration */
3484 MIG_ITERATE_SKIP
, /* Skip current iteration */
3485 MIG_ITERATE_BREAK
, /* Break the loop */
3489 * Return true if continue to the next iteration directly, false
3492 static MigIterateState
migration_iteration_run(MigrationState
*s
)
3494 uint64_t pending_size
, pend_pre
, pend_compat
, pend_post
;
3495 bool in_postcopy
= s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
;
3497 qemu_savevm_state_pending(s
->to_dst_file
, s
->threshold_size
, &pend_pre
,
3498 &pend_compat
, &pend_post
);
3499 pending_size
= pend_pre
+ pend_compat
+ pend_post
;
3501 trace_migrate_pending(pending_size
, s
->threshold_size
,
3502 pend_pre
, pend_compat
, pend_post
);
3504 if (pending_size
&& pending_size
>= s
->threshold_size
) {
3505 /* Still a significant amount to transfer */
3506 if (!in_postcopy
&& pend_pre
<= s
->threshold_size
&&
3507 qatomic_read(&s
->start_postcopy
)) {
3508 if (postcopy_start(s
)) {
3509 error_report("%s: postcopy failed to start", __func__
);
3511 return MIG_ITERATE_SKIP
;
3513 /* Just another iteration step */
3514 qemu_savevm_state_iterate(s
->to_dst_file
, in_postcopy
);
3516 trace_migration_thread_low_pending(pending_size
);
3517 migration_completion(s
);
3518 return MIG_ITERATE_BREAK
;
3521 return MIG_ITERATE_RESUME
;
3524 static void migration_iteration_finish(MigrationState
*s
)
3526 /* If we enabled cpu throttling for auto-converge, turn it off. */
3527 cpu_throttle_stop();
3529 qemu_mutex_lock_iothread();
3531 case MIGRATION_STATUS_COMPLETED
:
3532 migration_calculate_complete(s
);
3533 runstate_set(RUN_STATE_POSTMIGRATE
);
3536 case MIGRATION_STATUS_ACTIVE
:
3538 * We should really assert here, but since it's during
3539 * migration, let's try to reduce the usage of assertions.
3541 if (!migrate_colo_enabled()) {
3542 error_report("%s: critical error: calling COLO code without "
3543 "COLO enabled", __func__
);
3545 migrate_start_colo_process(s
);
3547 * Fixme: we will run VM in COLO no matter its old running state.
3548 * After exited COLO, we will keep running.
3550 s
->vm_was_running
= true;
3552 case MIGRATION_STATUS_FAILED
:
3553 case MIGRATION_STATUS_CANCELLED
:
3554 case MIGRATION_STATUS_CANCELLING
:
3555 if (s
->vm_was_running
) {
3558 if (runstate_check(RUN_STATE_FINISH_MIGRATE
)) {
3559 runstate_set(RUN_STATE_POSTMIGRATE
);
3565 /* Should not reach here, but if so, forgive the VM. */
3566 error_report("%s: Unknown ending state %d", __func__
, s
->state
);
3569 migrate_fd_cleanup_schedule(s
);
3570 qemu_mutex_unlock_iothread();
3573 static void bg_migration_iteration_finish(MigrationState
*s
)
3575 qemu_mutex_lock_iothread();
3577 case MIGRATION_STATUS_COMPLETED
:
3578 migration_calculate_complete(s
);
3581 case MIGRATION_STATUS_ACTIVE
:
3582 case MIGRATION_STATUS_FAILED
:
3583 case MIGRATION_STATUS_CANCELLED
:
3584 case MIGRATION_STATUS_CANCELLING
:
3588 /* Should not reach here, but if so, forgive the VM. */
3589 error_report("%s: Unknown ending state %d", __func__
, s
->state
);
3593 migrate_fd_cleanup_schedule(s
);
3594 qemu_mutex_unlock_iothread();
3598 * Return true if continue to the next iteration directly, false
3601 static MigIterateState
bg_migration_iteration_run(MigrationState
*s
)
3605 res
= qemu_savevm_state_iterate(s
->to_dst_file
, false);
3607 bg_migration_completion(s
);
3608 return MIG_ITERATE_BREAK
;
3611 return MIG_ITERATE_RESUME
;
3614 void migration_make_urgent_request(void)
3616 qemu_sem_post(&migrate_get_current()->rate_limit_sem
);
3619 void migration_consume_urgent_request(void)
3621 qemu_sem_wait(&migrate_get_current()->rate_limit_sem
);
3624 /* Returns true if the rate limiting was broken by an urgent request */
3625 bool migration_rate_limit(void)
3627 int64_t now
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3628 MigrationState
*s
= migrate_get_current();
3630 bool urgent
= false;
3631 migration_update_counters(s
, now
);
3632 if (qemu_file_rate_limit(s
->to_dst_file
)) {
3634 if (qemu_file_get_error(s
->to_dst_file
)) {
3638 * Wait for a delay to do rate limiting OR
3639 * something urgent to post the semaphore.
3641 int ms
= s
->iteration_start_time
+ BUFFER_DELAY
- now
;
3642 trace_migration_rate_limit_pre(ms
);
3643 if (qemu_sem_timedwait(&s
->rate_limit_sem
, ms
) == 0) {
3645 * We were woken by one or more urgent things but
3646 * the timedwait will have consumed one of them.
3647 * The service routine for the urgent wake will dec
3648 * the semaphore itself for each item it consumes,
3649 * so add this one we just eat back.
3651 qemu_sem_post(&s
->rate_limit_sem
);
3654 trace_migration_rate_limit_post(urgent
);
3660 * Master migration thread on the source VM.
3661 * It drives the migration and pumps the data down the outgoing channel.
3663 static void *migration_thread(void *opaque
)
3665 MigrationState
*s
= opaque
;
3666 int64_t setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
3667 MigThrError thr_error
;
3668 bool urgent
= false;
3670 rcu_register_thread();
3672 object_ref(OBJECT(s
));
3673 update_iteration_initial_status(s
);
3675 qemu_savevm_state_header(s
->to_dst_file
);
3678 * If we opened the return path, we need to make sure dst has it
3681 if (s
->rp_state
.from_dst_file
) {
3682 /* Now tell the dest that it should open its end so it can reply */
3683 qemu_savevm_send_open_return_path(s
->to_dst_file
);
3685 /* And do a ping that will make stuff easier to debug */
3686 qemu_savevm_send_ping(s
->to_dst_file
, 1);
3689 if (migrate_postcopy()) {
3691 * Tell the destination that we *might* want to do postcopy later;
3692 * if the other end can't do postcopy it should fail now, nice and
3695 qemu_savevm_send_postcopy_advise(s
->to_dst_file
);
3698 if (migrate_colo_enabled()) {
3699 /* Notify migration destination that we enable COLO */
3700 qemu_savevm_send_colo_enable(s
->to_dst_file
);
3703 qemu_savevm_state_setup(s
->to_dst_file
);
3705 if (qemu_savevm_state_guest_unplug_pending()) {
3706 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3707 MIGRATION_STATUS_WAIT_UNPLUG
);
3709 while (s
->state
== MIGRATION_STATUS_WAIT_UNPLUG
&&
3710 qemu_savevm_state_guest_unplug_pending()) {
3711 qemu_sem_timedwait(&s
->wait_unplug_sem
, 250);
3714 migrate_set_state(&s
->state
, MIGRATION_STATUS_WAIT_UNPLUG
,
3715 MIGRATION_STATUS_ACTIVE
);
3718 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
3719 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3720 MIGRATION_STATUS_ACTIVE
);
3722 trace_migration_thread_setup_complete();
3724 while (migration_is_active(s
)) {
3725 if (urgent
|| !qemu_file_rate_limit(s
->to_dst_file
)) {
3726 MigIterateState iter_state
= migration_iteration_run(s
);
3727 if (iter_state
== MIG_ITERATE_SKIP
) {
3729 } else if (iter_state
== MIG_ITERATE_BREAK
) {
3735 * Try to detect any kind of failures, and see whether we
3736 * should stop the migration now.
3738 thr_error
= migration_detect_error(s
);
3739 if (thr_error
== MIG_THR_ERR_FATAL
) {
3740 /* Stop migration */
3742 } else if (thr_error
== MIG_THR_ERR_RECOVERED
) {
3744 * Just recovered from a e.g. network failure, reset all
3745 * the local variables. This is important to avoid
3746 * breaking transferred_bytes and bandwidth calculation
3748 update_iteration_initial_status(s
);
3751 urgent
= migration_rate_limit();
3754 trace_migration_thread_after_loop();
3755 migration_iteration_finish(s
);
3756 object_unref(OBJECT(s
));
3757 rcu_unregister_thread();
3761 static void bg_migration_vm_start_bh(void *opaque
)
3763 MigrationState
*s
= opaque
;
3765 qemu_bh_delete(s
->vm_start_bh
);
3766 s
->vm_start_bh
= NULL
;
3769 s
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - s
->downtime_start
;
3773 * Background snapshot thread, based on live migration code.
3774 * This is an alternative implementation of live migration mechanism
3775 * introduced specifically to support background snapshots.
3777 * It takes advantage of userfault_fd write protection mechanism introduced
3778 * in v5.7 kernel. Compared to existing dirty page logging migration much
3779 * lesser stream traffic is produced resulting in smaller snapshot images,
3780 * simply cause of no page duplicates can get into the stream.
3782 * Another key point is that generated vmstate stream reflects machine state
3783 * 'frozen' at the beginning of snapshot creation compared to dirty page logging
3784 * mechanism, which effectively results in that saved snapshot is the state of VM
3785 * at the end of the process.
3787 static void *bg_migration_thread(void *opaque
)
3789 MigrationState
*s
= opaque
;
3790 int64_t setup_start
;
3791 MigThrError thr_error
;
3793 bool early_fail
= true;
3795 rcu_register_thread();
3796 object_ref(OBJECT(s
));
3798 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
3800 setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
3802 * We want to save vmstate for the moment when migration has been
3803 * initiated but also we want to save RAM content while VM is running.
3804 * The RAM content should appear first in the vmstate. So, we first
3805 * stash the non-RAM part of the vmstate to the temporary buffer,
3806 * then write RAM part of the vmstate to the migration stream
3807 * with vCPUs running and, finally, write stashed non-RAM part of
3808 * the vmstate from the buffer to the migration stream.
3810 s
->bioc
= qio_channel_buffer_new(512 * 1024);
3811 qio_channel_set_name(QIO_CHANNEL(s
->bioc
), "vmstate-buffer");
3812 fb
= qemu_fopen_channel_output(QIO_CHANNEL(s
->bioc
));
3813 object_unref(OBJECT(s
->bioc
));
3815 update_iteration_initial_status(s
);
3818 * Prepare for tracking memory writes with UFFD-WP - populate
3819 * RAM pages before protecting.
3822 ram_write_tracking_prepare();
3825 qemu_savevm_state_header(s
->to_dst_file
);
3826 qemu_savevm_state_setup(s
->to_dst_file
);
3828 if (qemu_savevm_state_guest_unplug_pending()) {
3829 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3830 MIGRATION_STATUS_WAIT_UNPLUG
);
3832 while (s
->state
== MIGRATION_STATUS_WAIT_UNPLUG
&&
3833 qemu_savevm_state_guest_unplug_pending()) {
3834 qemu_sem_timedwait(&s
->wait_unplug_sem
, 250);
3837 migrate_set_state(&s
->state
, MIGRATION_STATUS_WAIT_UNPLUG
,
3838 MIGRATION_STATUS_ACTIVE
);
3840 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3841 MIGRATION_STATUS_ACTIVE
);
3843 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
3845 trace_migration_thread_setup_complete();
3846 s
->downtime_start
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3848 qemu_mutex_lock_iothread();
3851 * If VM is currently in suspended state, then, to make a valid runstate
3852 * transition in vm_stop_force_state() we need to wakeup it up.
3854 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
3855 s
->vm_was_running
= runstate_is_running();
3857 if (global_state_store()) {
3860 /* Forcibly stop VM before saving state of vCPUs and devices */
3861 if (vm_stop_force_state(RUN_STATE_PAUSED
)) {
3865 * Put vCPUs in sync with shadow context structures, then
3866 * save their state to channel-buffer along with devices.
3868 cpu_synchronize_all_states();
3869 if (qemu_savevm_state_complete_precopy_non_iterable(fb
, false, false)) {
3873 * Since we are going to get non-iterable state data directly
3874 * from s->bioc->data, explicit flush is needed here.
3878 /* Now initialize UFFD context and start tracking RAM writes */
3879 if (ram_write_tracking_start()) {
3885 * Start VM from BH handler to avoid write-fault lock here.
3886 * UFFD-WP protection for the whole RAM is already enabled so
3887 * calling VM state change notifiers from vm_start() would initiate
3888 * writes to virtio VQs memory which is in write-protected region.
3890 s
->vm_start_bh
= qemu_bh_new(bg_migration_vm_start_bh
, s
);
3891 qemu_bh_schedule(s
->vm_start_bh
);
3893 qemu_mutex_unlock_iothread();
3895 while (migration_is_active(s
)) {
3896 MigIterateState iter_state
= bg_migration_iteration_run(s
);
3897 if (iter_state
== MIG_ITERATE_SKIP
) {
3899 } else if (iter_state
== MIG_ITERATE_BREAK
) {
3904 * Try to detect any kind of failures, and see whether we
3905 * should stop the migration now.
3907 thr_error
= migration_detect_error(s
);
3908 if (thr_error
== MIG_THR_ERR_FATAL
) {
3909 /* Stop migration */
3913 migration_update_counters(s
, qemu_clock_get_ms(QEMU_CLOCK_REALTIME
));
3916 trace_migration_thread_after_loop();
3920 migrate_set_state(&s
->state
, MIGRATION_STATUS_ACTIVE
,
3921 MIGRATION_STATUS_FAILED
);
3922 qemu_mutex_unlock_iothread();
3925 bg_migration_iteration_finish(s
);
3928 object_unref(OBJECT(s
));
3929 rcu_unregister_thread();
3934 void migrate_fd_connect(MigrationState
*s
, Error
*error_in
)
3936 Error
*local_err
= NULL
;
3938 bool resume
= s
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
;
3940 s
->expected_downtime
= s
->parameters
.downtime_limit
;
3942 assert(s
->cleanup_bh
);
3944 assert(!s
->cleanup_bh
);
3945 s
->cleanup_bh
= qemu_bh_new(migrate_fd_cleanup_bh
, s
);
3948 migrate_fd_error(s
, error_in
);
3949 migrate_fd_cleanup(s
);
3954 /* This is a resumed migration */
3955 rate_limit
= s
->parameters
.max_postcopy_bandwidth
/
3958 /* This is a fresh new migration */
3959 rate_limit
= s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
;
3961 /* Notify before starting migration thread */
3962 notifier_list_notify(&migration_state_notifiers
, s
);
3965 qemu_file_set_rate_limit(s
->to_dst_file
, rate_limit
);
3966 qemu_file_set_blocking(s
->to_dst_file
, true);
3969 * Open the return path. For postcopy, it is used exclusively. For
3970 * precopy, only if user specified "return-path" capability would
3971 * QEMU uses the return path.
3973 if (migrate_postcopy_ram() || migrate_use_return_path()) {
3974 if (open_return_path_on_source(s
, !resume
)) {
3975 error_report("Unable to open return-path for postcopy");
3976 migrate_set_state(&s
->state
, s
->state
, MIGRATION_STATUS_FAILED
);
3977 migrate_fd_cleanup(s
);
3983 /* Wakeup the main migration thread to do the recovery */
3984 migrate_set_state(&s
->state
, MIGRATION_STATUS_POSTCOPY_PAUSED
,
3985 MIGRATION_STATUS_POSTCOPY_RECOVER
);
3986 qemu_sem_post(&s
->postcopy_pause_sem
);
3990 if (multifd_save_setup(&local_err
) != 0) {
3991 error_report_err(local_err
);
3992 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3993 MIGRATION_STATUS_FAILED
);
3994 migrate_fd_cleanup(s
);
3998 if (migrate_background_snapshot()) {
3999 qemu_thread_create(&s
->thread
, "bg_snapshot",
4000 bg_migration_thread
, s
, QEMU_THREAD_JOINABLE
);
4002 qemu_thread_create(&s
->thread
, "live_migration",
4003 migration_thread
, s
, QEMU_THREAD_JOINABLE
);
4005 s
->migration_thread_running
= true;
4008 void migration_global_dump(Monitor
*mon
)
4010 MigrationState
*ms
= migrate_get_current();
4012 monitor_printf(mon
, "globals:\n");
4013 monitor_printf(mon
, "store-global-state: %s\n",
4014 ms
->store_global_state
? "on" : "off");
4015 monitor_printf(mon
, "only-migratable: %s\n",
4016 only_migratable
? "on" : "off");
4017 monitor_printf(mon
, "send-configuration: %s\n",
4018 ms
->send_configuration
? "on" : "off");
4019 monitor_printf(mon
, "send-section-footer: %s\n",
4020 ms
->send_section_footer
? "on" : "off");
4021 monitor_printf(mon
, "decompress-error-check: %s\n",
4022 ms
->decompress_error_check
? "on" : "off");
4023 monitor_printf(mon
, "clear-bitmap-shift: %u\n",
4024 ms
->clear_bitmap_shift
);
4027 #define DEFINE_PROP_MIG_CAP(name, x) \
4028 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false)
4030 static Property migration_properties
[] = {
4031 DEFINE_PROP_BOOL("store-global-state", MigrationState
,
4032 store_global_state
, true),
4033 DEFINE_PROP_BOOL("send-configuration", MigrationState
,
4034 send_configuration
, true),
4035 DEFINE_PROP_BOOL("send-section-footer", MigrationState
,
4036 send_section_footer
, true),
4037 DEFINE_PROP_BOOL("decompress-error-check", MigrationState
,
4038 decompress_error_check
, true),
4039 DEFINE_PROP_UINT8("x-clear-bitmap-shift", MigrationState
,
4040 clear_bitmap_shift
, CLEAR_BITMAP_SHIFT_DEFAULT
),
4042 /* Migration parameters */
4043 DEFINE_PROP_UINT8("x-compress-level", MigrationState
,
4044 parameters
.compress_level
,
4045 DEFAULT_MIGRATE_COMPRESS_LEVEL
),
4046 DEFINE_PROP_UINT8("x-compress-threads", MigrationState
,
4047 parameters
.compress_threads
,
4048 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT
),
4049 DEFINE_PROP_BOOL("x-compress-wait-thread", MigrationState
,
4050 parameters
.compress_wait_thread
, true),
4051 DEFINE_PROP_UINT8("x-decompress-threads", MigrationState
,
4052 parameters
.decompress_threads
,
4053 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT
),
4054 DEFINE_PROP_UINT8("x-throttle-trigger-threshold", MigrationState
,
4055 parameters
.throttle_trigger_threshold
,
4056 DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD
),
4057 DEFINE_PROP_UINT8("x-cpu-throttle-initial", MigrationState
,
4058 parameters
.cpu_throttle_initial
,
4059 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL
),
4060 DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState
,
4061 parameters
.cpu_throttle_increment
,
4062 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT
),
4063 DEFINE_PROP_BOOL("x-cpu-throttle-tailslow", MigrationState
,
4064 parameters
.cpu_throttle_tailslow
, false),
4065 DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState
,
4066 parameters
.max_bandwidth
, MAX_THROTTLE
),
4067 DEFINE_PROP_UINT64("x-downtime-limit", MigrationState
,
4068 parameters
.downtime_limit
,
4069 DEFAULT_MIGRATE_SET_DOWNTIME
),
4070 DEFINE_PROP_UINT32("x-checkpoint-delay", MigrationState
,
4071 parameters
.x_checkpoint_delay
,
4072 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY
),
4073 DEFINE_PROP_UINT8("multifd-channels", MigrationState
,
4074 parameters
.multifd_channels
,
4075 DEFAULT_MIGRATE_MULTIFD_CHANNELS
),
4076 DEFINE_PROP_MULTIFD_COMPRESSION("multifd-compression", MigrationState
,
4077 parameters
.multifd_compression
,
4078 DEFAULT_MIGRATE_MULTIFD_COMPRESSION
),
4079 DEFINE_PROP_UINT8("multifd-zlib-level", MigrationState
,
4080 parameters
.multifd_zlib_level
,
4081 DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL
),
4082 DEFINE_PROP_UINT8("multifd-zstd-level", MigrationState
,
4083 parameters
.multifd_zstd_level
,
4084 DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL
),
4085 DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState
,
4086 parameters
.xbzrle_cache_size
,
4087 DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE
),
4088 DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState
,
4089 parameters
.max_postcopy_bandwidth
,
4090 DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH
),
4091 DEFINE_PROP_UINT8("max-cpu-throttle", MigrationState
,
4092 parameters
.max_cpu_throttle
,
4093 DEFAULT_MIGRATE_MAX_CPU_THROTTLE
),
4094 DEFINE_PROP_SIZE("announce-initial", MigrationState
,
4095 parameters
.announce_initial
,
4096 DEFAULT_MIGRATE_ANNOUNCE_INITIAL
),
4097 DEFINE_PROP_SIZE("announce-max", MigrationState
,
4098 parameters
.announce_max
,
4099 DEFAULT_MIGRATE_ANNOUNCE_MAX
),
4100 DEFINE_PROP_SIZE("announce-rounds", MigrationState
,
4101 parameters
.announce_rounds
,
4102 DEFAULT_MIGRATE_ANNOUNCE_ROUNDS
),
4103 DEFINE_PROP_SIZE("announce-step", MigrationState
,
4104 parameters
.announce_step
,
4105 DEFAULT_MIGRATE_ANNOUNCE_STEP
),
4107 /* Migration capabilities */
4108 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE
),
4109 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL
),
4110 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE
),
4111 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS
),
4112 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS
),
4113 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS
),
4114 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM
),
4115 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO
),
4116 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM
),
4117 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK
),
4118 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH
),
4119 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_MULTIFD
),
4120 DEFINE_PROP_MIG_CAP("x-background-snapshot",
4121 MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
),
4123 DEFINE_PROP_END_OF_LIST(),
4126 static void migration_class_init(ObjectClass
*klass
, void *data
)
4128 DeviceClass
*dc
= DEVICE_CLASS(klass
);
4130 dc
->user_creatable
= false;
4131 device_class_set_props(dc
, migration_properties
);
4134 static void migration_instance_finalize(Object
*obj
)
4136 MigrationState
*ms
= MIGRATION_OBJ(obj
);
4137 MigrationParameters
*params
= &ms
->parameters
;
4139 qemu_mutex_destroy(&ms
->error_mutex
);
4140 qemu_mutex_destroy(&ms
->qemu_file_lock
);
4141 g_free(params
->tls_hostname
);
4142 g_free(params
->tls_creds
);
4143 qemu_sem_destroy(&ms
->wait_unplug_sem
);
4144 qemu_sem_destroy(&ms
->rate_limit_sem
);
4145 qemu_sem_destroy(&ms
->pause_sem
);
4146 qemu_sem_destroy(&ms
->postcopy_pause_sem
);
4147 qemu_sem_destroy(&ms
->postcopy_pause_rp_sem
);
4148 qemu_sem_destroy(&ms
->rp_state
.rp_sem
);
4149 error_free(ms
->error
);
4152 static void migration_instance_init(Object
*obj
)
4154 MigrationState
*ms
= MIGRATION_OBJ(obj
);
4155 MigrationParameters
*params
= &ms
->parameters
;
4157 ms
->state
= MIGRATION_STATUS_NONE
;
4159 ms
->pages_per_second
= -1;
4160 qemu_sem_init(&ms
->pause_sem
, 0);
4161 qemu_mutex_init(&ms
->error_mutex
);
4163 params
->tls_hostname
= g_strdup("");
4164 params
->tls_creds
= g_strdup("");
4166 /* Set has_* up only for parameter checks */
4167 params
->has_compress_level
= true;
4168 params
->has_compress_threads
= true;
4169 params
->has_decompress_threads
= true;
4170 params
->has_throttle_trigger_threshold
= true;
4171 params
->has_cpu_throttle_initial
= true;
4172 params
->has_cpu_throttle_increment
= true;
4173 params
->has_cpu_throttle_tailslow
= true;
4174 params
->has_max_bandwidth
= true;
4175 params
->has_downtime_limit
= true;
4176 params
->has_x_checkpoint_delay
= true;
4177 params
->has_block_incremental
= true;
4178 params
->has_multifd_channels
= true;
4179 params
->has_multifd_compression
= true;
4180 params
->has_multifd_zlib_level
= true;
4181 params
->has_multifd_zstd_level
= true;
4182 params
->has_xbzrle_cache_size
= true;
4183 params
->has_max_postcopy_bandwidth
= true;
4184 params
->has_max_cpu_throttle
= true;
4185 params
->has_announce_initial
= true;
4186 params
->has_announce_max
= true;
4187 params
->has_announce_rounds
= true;
4188 params
->has_announce_step
= true;
4190 qemu_sem_init(&ms
->postcopy_pause_sem
, 0);
4191 qemu_sem_init(&ms
->postcopy_pause_rp_sem
, 0);
4192 qemu_sem_init(&ms
->rp_state
.rp_sem
, 0);
4193 qemu_sem_init(&ms
->rate_limit_sem
, 0);
4194 qemu_sem_init(&ms
->wait_unplug_sem
, 0);
4195 qemu_mutex_init(&ms
->qemu_file_lock
);
4199 * Return true if check pass, false otherwise. Error will be put
4200 * inside errp if provided.
4202 static bool migration_object_check(MigrationState
*ms
, Error
**errp
)
4204 MigrationCapabilityStatusList
*head
= NULL
;
4205 /* Assuming all off */
4206 bool cap_list
[MIGRATION_CAPABILITY__MAX
] = { 0 }, ret
;
4209 if (!migrate_params_check(&ms
->parameters
, errp
)) {
4213 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
4214 if (ms
->enabled_capabilities
[i
]) {
4215 QAPI_LIST_PREPEND(head
, migrate_cap_add(i
, true));
4219 ret
= migrate_caps_check(cap_list
, head
, errp
);
4221 /* It works with head == NULL */
4222 qapi_free_MigrationCapabilityStatusList(head
);
4227 static const TypeInfo migration_type
= {
4228 .name
= TYPE_MIGRATION
,
4230 * NOTE: TYPE_MIGRATION is not really a device, as the object is
4231 * not created using qdev_new(), it is not attached to the qdev
4232 * device tree, and it is never realized.
4234 * TODO: Make this TYPE_OBJECT once QOM provides something like
4235 * TYPE_DEVICE's "-global" properties.
4237 .parent
= TYPE_DEVICE
,
4238 .class_init
= migration_class_init
,
4239 .class_size
= sizeof(MigrationClass
),
4240 .instance_size
= sizeof(MigrationState
),
4241 .instance_init
= migration_instance_init
,
4242 .instance_finalize
= migration_instance_finalize
,
4245 static void register_migration_types(void)
4247 type_register_static(&migration_type
);
4250 type_init(register_migration_types
);