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_shutdown(void)
225 * Cancel the current migration - that will (eventually)
226 * stop the migration using this structure
228 migrate_fd_cancel(current_migration
);
229 object_unref(OBJECT(current_migration
));
232 * Cancel outgoing migration of dirty bitmaps. It should
233 * at least unref used block nodes.
235 dirty_bitmap_mig_cancel_outgoing();
238 * Cancel incoming migration of dirty bitmaps. Dirty bitmaps
239 * are non-critical data, and their loss never considered as
242 dirty_bitmap_mig_cancel_incoming();
246 MigrationState
*migrate_get_current(void)
248 /* This can only be called after the object created. */
249 assert(current_migration
);
250 return current_migration
;
253 MigrationIncomingState
*migration_incoming_get_current(void)
255 assert(current_incoming
);
256 return current_incoming
;
259 void migration_incoming_state_destroy(void)
261 struct MigrationIncomingState
*mis
= migration_incoming_get_current();
263 if (mis
->to_src_file
) {
264 /* Tell source that we are done */
265 migrate_send_rp_shut(mis
, qemu_file_get_error(mis
->from_src_file
) != 0);
266 qemu_fclose(mis
->to_src_file
);
267 mis
->to_src_file
= NULL
;
270 if (mis
->from_src_file
) {
271 qemu_fclose(mis
->from_src_file
);
272 mis
->from_src_file
= NULL
;
274 if (mis
->postcopy_remote_fds
) {
275 g_array_free(mis
->postcopy_remote_fds
, TRUE
);
276 mis
->postcopy_remote_fds
= NULL
;
279 qemu_event_reset(&mis
->main_thread_load_event
);
281 if (mis
->page_requested
) {
282 g_tree_destroy(mis
->page_requested
);
283 mis
->page_requested
= NULL
;
286 if (mis
->socket_address_list
) {
287 qapi_free_SocketAddressList(mis
->socket_address_list
);
288 mis
->socket_address_list
= NULL
;
291 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
294 static void migrate_generate_event(int new_state
)
296 if (migrate_use_events()) {
297 qapi_event_send_migration(new_state
);
301 static bool migrate_late_block_activate(void)
305 s
= migrate_get_current();
307 return s
->enabled_capabilities
[
308 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE
];
312 * Send a message on the return channel back to the source
315 static int migrate_send_rp_message(MigrationIncomingState
*mis
,
316 enum mig_rp_message_type message_type
,
317 uint16_t len
, void *data
)
321 trace_migrate_send_rp_message((int)message_type
, len
);
322 QEMU_LOCK_GUARD(&mis
->rp_mutex
);
325 * It's possible that the file handle got lost due to network
328 if (!mis
->to_src_file
) {
333 qemu_put_be16(mis
->to_src_file
, (unsigned int)message_type
);
334 qemu_put_be16(mis
->to_src_file
, len
);
335 qemu_put_buffer(mis
->to_src_file
, data
, len
);
336 qemu_fflush(mis
->to_src_file
);
338 /* It's possible that qemu file got error during sending */
339 ret
= qemu_file_get_error(mis
->to_src_file
);
344 /* Request one page from the source VM at the given start address.
345 * rb: the RAMBlock to request the page in
346 * Start: Address offset within the RB
347 * Len: Length in bytes required - must be a multiple of pagesize
349 int migrate_send_rp_message_req_pages(MigrationIncomingState
*mis
,
350 RAMBlock
*rb
, ram_addr_t start
)
352 uint8_t bufc
[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
353 size_t msglen
= 12; /* start + len */
354 size_t len
= qemu_ram_pagesize(rb
);
355 enum mig_rp_message_type msg_type
;
359 *(uint64_t *)bufc
= cpu_to_be64((uint64_t)start
);
360 *(uint32_t *)(bufc
+ 8) = cpu_to_be32((uint32_t)len
);
363 * We maintain the last ramblock that we requested for page. Note that we
364 * don't need locking because this function will only be called within the
365 * postcopy ram fault thread.
367 if (rb
!= mis
->last_rb
) {
370 rbname
= qemu_ram_get_idstr(rb
);
371 rbname_len
= strlen(rbname
);
373 assert(rbname_len
< 256);
375 bufc
[msglen
++] = rbname_len
;
376 memcpy(bufc
+ msglen
, rbname
, rbname_len
);
377 msglen
+= rbname_len
;
378 msg_type
= MIG_RP_MSG_REQ_PAGES_ID
;
380 msg_type
= MIG_RP_MSG_REQ_PAGES
;
383 return migrate_send_rp_message(mis
, msg_type
, msglen
, bufc
);
386 int migrate_send_rp_req_pages(MigrationIncomingState
*mis
,
387 RAMBlock
*rb
, ram_addr_t start
, uint64_t haddr
)
389 void *aligned
= (void *)(uintptr_t)(haddr
& (-qemu_ram_pagesize(rb
)));
390 bool received
= false;
392 WITH_QEMU_LOCK_GUARD(&mis
->page_request_mutex
) {
393 received
= ramblock_recv_bitmap_test_byte_offset(rb
, start
);
394 if (!received
&& !g_tree_lookup(mis
->page_requested
, aligned
)) {
396 * The page has not been received, and it's not yet in the page
397 * request list. Queue it. Set the value of element to 1, so that
398 * things like g_tree_lookup() will return TRUE (1) when found.
400 g_tree_insert(mis
->page_requested
, aligned
, (gpointer
)1);
401 mis
->page_requested_count
++;
402 trace_postcopy_page_req_add(aligned
, mis
->page_requested_count
);
407 * If the page is there, skip sending the message. We don't even need the
408 * lock because as long as the page arrived, it'll be there forever.
414 return migrate_send_rp_message_req_pages(mis
, rb
, start
);
417 static bool migration_colo_enabled
;
418 bool migration_incoming_colo_enabled(void)
420 return migration_colo_enabled
;
423 void migration_incoming_disable_colo(void)
425 ram_block_discard_disable(false);
426 migration_colo_enabled
= false;
429 int migration_incoming_enable_colo(void)
431 if (ram_block_discard_disable(true)) {
432 error_report("COLO: cannot disable RAM discard");
435 migration_colo_enabled
= true;
439 void migrate_add_address(SocketAddress
*address
)
441 MigrationIncomingState
*mis
= migration_incoming_get_current();
443 QAPI_LIST_PREPEND(mis
->socket_address_list
,
444 QAPI_CLONE(SocketAddress
, address
));
447 static void qemu_start_incoming_migration(const char *uri
, Error
**errp
)
449 const char *p
= NULL
;
451 if (!yank_register_instance(MIGRATION_YANK_INSTANCE
, errp
)) {
455 qapi_event_send_migration(MIGRATION_STATUS_SETUP
);
456 if (strstart(uri
, "tcp:", &p
) ||
457 strstart(uri
, "unix:", NULL
) ||
458 strstart(uri
, "vsock:", NULL
)) {
459 socket_start_incoming_migration(p
? p
: uri
, errp
);
461 } else if (strstart(uri
, "rdma:", &p
)) {
462 rdma_start_incoming_migration(p
, errp
);
464 } else if (strstart(uri
, "exec:", &p
)) {
465 exec_start_incoming_migration(p
, errp
);
466 } else if (strstart(uri
, "fd:", &p
)) {
467 fd_start_incoming_migration(p
, errp
);
469 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
470 error_setg(errp
, "unknown migration protocol: %s", uri
);
474 static void process_incoming_migration_bh(void *opaque
)
476 Error
*local_err
= NULL
;
477 MigrationIncomingState
*mis
= opaque
;
479 /* If capability late_block_activate is set:
480 * Only fire up the block code now if we're going to restart the
481 * VM, else 'cont' will do it.
482 * This causes file locking to happen; so we don't want it to happen
483 * unless we really are starting the VM.
485 if (!migrate_late_block_activate() ||
486 (autostart
&& (!global_state_received() ||
487 global_state_get_runstate() == RUN_STATE_RUNNING
))) {
488 /* Make sure all file formats flush their mutable metadata.
489 * If we get an error here, just don't restart the VM yet. */
490 bdrv_invalidate_cache_all(&local_err
);
492 error_report_err(local_err
);
499 * This must happen after all error conditions are dealt with and
500 * we're sure the VM is going to be running on this host.
502 qemu_announce_self(&mis
->announce_timer
, migrate_announce_params());
504 if (multifd_load_cleanup(&local_err
) != 0) {
505 error_report_err(local_err
);
508 /* If global state section was not received or we are in running
509 state, we need to obey autostart. Any other state is set with
512 dirty_bitmap_mig_before_vm_start();
514 if (!global_state_received() ||
515 global_state_get_runstate() == RUN_STATE_RUNNING
) {
519 runstate_set(RUN_STATE_PAUSED
);
521 } else if (migration_incoming_colo_enabled()) {
522 migration_incoming_disable_colo();
525 runstate_set(global_state_get_runstate());
528 * This must happen after any state changes since as soon as an external
529 * observer sees this event they might start to prod at the VM assuming
532 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
533 MIGRATION_STATUS_COMPLETED
);
534 qemu_bh_delete(mis
->bh
);
535 migration_incoming_state_destroy();
538 static void process_incoming_migration_co(void *opaque
)
540 MigrationIncomingState
*mis
= migration_incoming_get_current();
543 Error
*local_err
= NULL
;
545 assert(mis
->from_src_file
);
546 mis
->migration_incoming_co
= qemu_coroutine_self();
547 mis
->largest_page_size
= qemu_ram_pagesize_largest();
548 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
549 migrate_set_state(&mis
->state
, MIGRATION_STATUS_NONE
,
550 MIGRATION_STATUS_ACTIVE
);
551 ret
= qemu_loadvm_state(mis
->from_src_file
);
553 ps
= postcopy_state_get();
554 trace_process_incoming_migration_co_end(ret
, ps
);
555 if (ps
!= POSTCOPY_INCOMING_NONE
) {
556 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
558 * Where a migration had postcopy enabled (and thus went to advise)
559 * but managed to complete within the precopy period, we can use
562 postcopy_ram_incoming_cleanup(mis
);
563 } else if (ret
>= 0) {
565 * Postcopy was started, cleanup should happen at the end of the
568 trace_process_incoming_migration_co_postcopy_end_main();
571 /* Else if something went wrong then just fall out of the normal exit */
574 /* we get COLO info, and know if we are in COLO mode */
575 if (!ret
&& migration_incoming_colo_enabled()) {
576 /* Make sure all file formats flush their mutable metadata */
577 bdrv_invalidate_cache_all(&local_err
);
579 error_report_err(local_err
);
583 qemu_thread_create(&mis
->colo_incoming_thread
, "COLO incoming",
584 colo_process_incoming_thread
, mis
, QEMU_THREAD_JOINABLE
);
585 mis
->have_colo_incoming_thread
= true;
586 qemu_coroutine_yield();
588 /* Wait checkpoint incoming thread exit before free resource */
589 qemu_thread_join(&mis
->colo_incoming_thread
);
590 /* We hold the global iothread lock, so it is safe here */
591 colo_release_ram_cache();
595 error_report("load of migration failed: %s", strerror(-ret
));
598 mis
->bh
= qemu_bh_new(process_incoming_migration_bh
, mis
);
599 qemu_bh_schedule(mis
->bh
);
600 mis
->migration_incoming_co
= NULL
;
604 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
605 MIGRATION_STATUS_FAILED
);
606 qemu_fclose(mis
->from_src_file
);
607 if (multifd_load_cleanup(&local_err
) != 0) {
608 error_report_err(local_err
);
614 * @migration_incoming_setup: Setup incoming migration
616 * Returns 0 for no error or 1 for error
618 * @f: file for main migration channel
619 * @errp: where to put errors
621 static int migration_incoming_setup(QEMUFile
*f
, Error
**errp
)
623 MigrationIncomingState
*mis
= migration_incoming_get_current();
624 Error
*local_err
= NULL
;
626 if (multifd_load_setup(&local_err
) != 0) {
627 /* We haven't been able to create multifd threads
628 nothing better to do */
629 error_report_err(local_err
);
633 if (!mis
->from_src_file
) {
634 mis
->from_src_file
= f
;
636 qemu_file_set_blocking(f
, false);
640 void migration_incoming_process(void)
642 Coroutine
*co
= qemu_coroutine_create(process_incoming_migration_co
, NULL
);
643 qemu_coroutine_enter(co
);
646 /* Returns true if recovered from a paused migration, otherwise false */
647 static bool postcopy_try_recover(QEMUFile
*f
)
649 MigrationIncomingState
*mis
= migration_incoming_get_current();
651 if (mis
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
652 /* Resumed from a paused postcopy migration */
654 mis
->from_src_file
= f
;
655 /* Postcopy has standalone thread to do vm load */
656 qemu_file_set_blocking(f
, true);
658 /* Re-configure the return path */
659 mis
->to_src_file
= qemu_file_get_return_path(f
);
661 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_PAUSED
,
662 MIGRATION_STATUS_POSTCOPY_RECOVER
);
665 * Here, we only wake up the main loading thread (while the
666 * fault thread will still be waiting), so that we can receive
667 * commands from source now, and answer it if needed. The
668 * fault thread will be woken up afterwards until we are sure
669 * that source is ready to reply to page requests.
671 qemu_sem_post(&mis
->postcopy_pause_sem_dst
);
678 void migration_fd_process_incoming(QEMUFile
*f
, Error
**errp
)
680 Error
*local_err
= NULL
;
682 if (postcopy_try_recover(f
)) {
686 if (migration_incoming_setup(f
, &local_err
)) {
687 error_propagate(errp
, local_err
);
690 migration_incoming_process();
693 void migration_ioc_process_incoming(QIOChannel
*ioc
, Error
**errp
)
695 MigrationIncomingState
*mis
= migration_incoming_get_current();
696 Error
*local_err
= NULL
;
697 bool start_migration
;
699 if (!mis
->from_src_file
) {
700 /* The first connection (multifd may have multiple) */
701 QEMUFile
*f
= qemu_fopen_channel_input(ioc
);
703 /* If it's a recovery, we're done */
704 if (postcopy_try_recover(f
)) {
708 if (migration_incoming_setup(f
, &local_err
)) {
709 error_propagate(errp
, local_err
);
714 * Common migration only needs one channel, so we can start
715 * right now. Multifd needs more than one channel, we wait.
717 start_migration
= !migrate_use_multifd();
719 /* Multiple connections */
720 assert(migrate_use_multifd());
721 start_migration
= multifd_recv_new_channel(ioc
, &local_err
);
723 error_propagate(errp
, local_err
);
728 if (start_migration
) {
729 migration_incoming_process();
734 * @migration_has_all_channels: We have received all channels that we need
736 * Returns true when we have got connections to all the channels that
737 * we need for migration.
739 bool migration_has_all_channels(void)
741 MigrationIncomingState
*mis
= migration_incoming_get_current();
744 all_channels
= multifd_recv_all_channels_created();
746 return all_channels
&& mis
->from_src_file
!= NULL
;
750 * Send a 'SHUT' message on the return channel with the given value
751 * to indicate that we've finished with the RP. Non-0 value indicates
754 void migrate_send_rp_shut(MigrationIncomingState
*mis
,
759 buf
= cpu_to_be32(value
);
760 migrate_send_rp_message(mis
, MIG_RP_MSG_SHUT
, sizeof(buf
), &buf
);
764 * Send a 'PONG' message on the return channel with the given value
765 * (normally in response to a 'PING')
767 void migrate_send_rp_pong(MigrationIncomingState
*mis
,
772 buf
= cpu_to_be32(value
);
773 migrate_send_rp_message(mis
, MIG_RP_MSG_PONG
, sizeof(buf
), &buf
);
776 void migrate_send_rp_recv_bitmap(MigrationIncomingState
*mis
,
784 * First, we send the header part. It contains only the len of
785 * idstr, and the idstr itself.
787 len
= strlen(block_name
);
789 memcpy(buf
+ 1, block_name
, len
);
791 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_RECOVER
) {
792 error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
797 migrate_send_rp_message(mis
, MIG_RP_MSG_RECV_BITMAP
, len
+ 1, buf
);
800 * Next, we dump the received bitmap to the stream.
802 * TODO: currently we are safe since we are the only one that is
803 * using the to_src_file handle (fault thread is still paused),
804 * and it's ok even not taking the mutex. However the best way is
805 * to take the lock before sending the message header, and release
806 * the lock after sending the bitmap.
808 qemu_mutex_lock(&mis
->rp_mutex
);
809 res
= ramblock_recv_bitmap_send(mis
->to_src_file
, block_name
);
810 qemu_mutex_unlock(&mis
->rp_mutex
);
812 trace_migrate_send_rp_recv_bitmap(block_name
, res
);
815 void migrate_send_rp_resume_ack(MigrationIncomingState
*mis
, uint32_t value
)
819 buf
= cpu_to_be32(value
);
820 migrate_send_rp_message(mis
, MIG_RP_MSG_RESUME_ACK
, sizeof(buf
), &buf
);
823 MigrationCapabilityStatusList
*qmp_query_migrate_capabilities(Error
**errp
)
825 MigrationCapabilityStatusList
*head
= NULL
, **tail
= &head
;
826 MigrationCapabilityStatus
*caps
;
827 MigrationState
*s
= migrate_get_current();
830 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
831 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
832 if (i
== MIGRATION_CAPABILITY_BLOCK
) {
836 caps
= g_malloc0(sizeof(*caps
));
837 caps
->capability
= i
;
838 caps
->state
= s
->enabled_capabilities
[i
];
839 QAPI_LIST_APPEND(tail
, caps
);
845 MigrationParameters
*qmp_query_migrate_parameters(Error
**errp
)
847 MigrationParameters
*params
;
848 MigrationState
*s
= migrate_get_current();
850 /* TODO use QAPI_CLONE() instead of duplicating it inline */
851 params
= g_malloc0(sizeof(*params
));
852 params
->has_compress_level
= true;
853 params
->compress_level
= s
->parameters
.compress_level
;
854 params
->has_compress_threads
= true;
855 params
->compress_threads
= s
->parameters
.compress_threads
;
856 params
->has_compress_wait_thread
= true;
857 params
->compress_wait_thread
= s
->parameters
.compress_wait_thread
;
858 params
->has_decompress_threads
= true;
859 params
->decompress_threads
= s
->parameters
.decompress_threads
;
860 params
->has_throttle_trigger_threshold
= true;
861 params
->throttle_trigger_threshold
= s
->parameters
.throttle_trigger_threshold
;
862 params
->has_cpu_throttle_initial
= true;
863 params
->cpu_throttle_initial
= s
->parameters
.cpu_throttle_initial
;
864 params
->has_cpu_throttle_increment
= true;
865 params
->cpu_throttle_increment
= s
->parameters
.cpu_throttle_increment
;
866 params
->has_cpu_throttle_tailslow
= true;
867 params
->cpu_throttle_tailslow
= s
->parameters
.cpu_throttle_tailslow
;
868 params
->has_tls_creds
= true;
869 params
->tls_creds
= g_strdup(s
->parameters
.tls_creds
);
870 params
->has_tls_hostname
= true;
871 params
->tls_hostname
= g_strdup(s
->parameters
.tls_hostname
);
872 params
->has_tls_authz
= true;
873 params
->tls_authz
= g_strdup(s
->parameters
.tls_authz
?
874 s
->parameters
.tls_authz
: "");
875 params
->has_max_bandwidth
= true;
876 params
->max_bandwidth
= s
->parameters
.max_bandwidth
;
877 params
->has_downtime_limit
= true;
878 params
->downtime_limit
= s
->parameters
.downtime_limit
;
879 params
->has_x_checkpoint_delay
= true;
880 params
->x_checkpoint_delay
= s
->parameters
.x_checkpoint_delay
;
881 params
->has_block_incremental
= true;
882 params
->block_incremental
= s
->parameters
.block_incremental
;
883 params
->has_multifd_channels
= true;
884 params
->multifd_channels
= s
->parameters
.multifd_channels
;
885 params
->has_multifd_compression
= true;
886 params
->multifd_compression
= s
->parameters
.multifd_compression
;
887 params
->has_multifd_zlib_level
= true;
888 params
->multifd_zlib_level
= s
->parameters
.multifd_zlib_level
;
889 params
->has_multifd_zstd_level
= true;
890 params
->multifd_zstd_level
= s
->parameters
.multifd_zstd_level
;
891 params
->has_xbzrle_cache_size
= true;
892 params
->xbzrle_cache_size
= s
->parameters
.xbzrle_cache_size
;
893 params
->has_max_postcopy_bandwidth
= true;
894 params
->max_postcopy_bandwidth
= s
->parameters
.max_postcopy_bandwidth
;
895 params
->has_max_cpu_throttle
= true;
896 params
->max_cpu_throttle
= s
->parameters
.max_cpu_throttle
;
897 params
->has_announce_initial
= true;
898 params
->announce_initial
= s
->parameters
.announce_initial
;
899 params
->has_announce_max
= true;
900 params
->announce_max
= s
->parameters
.announce_max
;
901 params
->has_announce_rounds
= true;
902 params
->announce_rounds
= s
->parameters
.announce_rounds
;
903 params
->has_announce_step
= true;
904 params
->announce_step
= s
->parameters
.announce_step
;
906 if (s
->parameters
.has_block_bitmap_mapping
) {
907 params
->has_block_bitmap_mapping
= true;
908 params
->block_bitmap_mapping
=
909 QAPI_CLONE(BitmapMigrationNodeAliasList
,
910 s
->parameters
.block_bitmap_mapping
);
916 AnnounceParameters
*migrate_announce_params(void)
918 static AnnounceParameters ap
;
920 MigrationState
*s
= migrate_get_current();
922 ap
.initial
= s
->parameters
.announce_initial
;
923 ap
.max
= s
->parameters
.announce_max
;
924 ap
.rounds
= s
->parameters
.announce_rounds
;
925 ap
.step
= s
->parameters
.announce_step
;
931 * Return true if we're already in the middle of a migration
932 * (i.e. any of the active or setup states)
934 bool migration_is_setup_or_active(int state
)
937 case MIGRATION_STATUS_ACTIVE
:
938 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
939 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
940 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
941 case MIGRATION_STATUS_SETUP
:
942 case MIGRATION_STATUS_PRE_SWITCHOVER
:
943 case MIGRATION_STATUS_DEVICE
:
944 case MIGRATION_STATUS_WAIT_UNPLUG
:
945 case MIGRATION_STATUS_COLO
:
954 bool migration_is_running(int state
)
957 case MIGRATION_STATUS_ACTIVE
:
958 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
959 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
960 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
961 case MIGRATION_STATUS_SETUP
:
962 case MIGRATION_STATUS_PRE_SWITCHOVER
:
963 case MIGRATION_STATUS_DEVICE
:
964 case MIGRATION_STATUS_WAIT_UNPLUG
:
965 case MIGRATION_STATUS_CANCELLING
:
974 static void populate_time_info(MigrationInfo
*info
, MigrationState
*s
)
976 info
->has_status
= true;
977 info
->has_setup_time
= true;
978 info
->setup_time
= s
->setup_time
;
979 if (s
->state
== MIGRATION_STATUS_COMPLETED
) {
980 info
->has_total_time
= true;
981 info
->total_time
= s
->total_time
;
982 info
->has_downtime
= true;
983 info
->downtime
= s
->downtime
;
985 info
->has_total_time
= true;
986 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) -
988 info
->has_expected_downtime
= true;
989 info
->expected_downtime
= s
->expected_downtime
;
993 static void populate_ram_info(MigrationInfo
*info
, MigrationState
*s
)
995 info
->has_ram
= true;
996 info
->ram
= g_malloc0(sizeof(*info
->ram
));
997 info
->ram
->transferred
= ram_counters
.transferred
;
998 info
->ram
->total
= ram_bytes_total();
999 info
->ram
->duplicate
= ram_counters
.duplicate
;
1000 /* legacy value. It is not used anymore */
1001 info
->ram
->skipped
= 0;
1002 info
->ram
->normal
= ram_counters
.normal
;
1003 info
->ram
->normal_bytes
= ram_counters
.normal
*
1004 qemu_target_page_size();
1005 info
->ram
->mbps
= s
->mbps
;
1006 info
->ram
->dirty_sync_count
= ram_counters
.dirty_sync_count
;
1007 info
->ram
->postcopy_requests
= ram_counters
.postcopy_requests
;
1008 info
->ram
->page_size
= qemu_target_page_size();
1009 info
->ram
->multifd_bytes
= ram_counters
.multifd_bytes
;
1010 info
->ram
->pages_per_second
= s
->pages_per_second
;
1012 if (migrate_use_xbzrle()) {
1013 info
->has_xbzrle_cache
= true;
1014 info
->xbzrle_cache
= g_malloc0(sizeof(*info
->xbzrle_cache
));
1015 info
->xbzrle_cache
->cache_size
= migrate_xbzrle_cache_size();
1016 info
->xbzrle_cache
->bytes
= xbzrle_counters
.bytes
;
1017 info
->xbzrle_cache
->pages
= xbzrle_counters
.pages
;
1018 info
->xbzrle_cache
->cache_miss
= xbzrle_counters
.cache_miss
;
1019 info
->xbzrle_cache
->cache_miss_rate
= xbzrle_counters
.cache_miss_rate
;
1020 info
->xbzrle_cache
->encoding_rate
= xbzrle_counters
.encoding_rate
;
1021 info
->xbzrle_cache
->overflow
= xbzrle_counters
.overflow
;
1024 if (migrate_use_compression()) {
1025 info
->has_compression
= true;
1026 info
->compression
= g_malloc0(sizeof(*info
->compression
));
1027 info
->compression
->pages
= compression_counters
.pages
;
1028 info
->compression
->busy
= compression_counters
.busy
;
1029 info
->compression
->busy_rate
= compression_counters
.busy_rate
;
1030 info
->compression
->compressed_size
=
1031 compression_counters
.compressed_size
;
1032 info
->compression
->compression_rate
=
1033 compression_counters
.compression_rate
;
1036 if (cpu_throttle_active()) {
1037 info
->has_cpu_throttle_percentage
= true;
1038 info
->cpu_throttle_percentage
= cpu_throttle_get_percentage();
1041 if (s
->state
!= MIGRATION_STATUS_COMPLETED
) {
1042 info
->ram
->remaining
= ram_bytes_remaining();
1043 info
->ram
->dirty_pages_rate
= ram_counters
.dirty_pages_rate
;
1047 static void populate_disk_info(MigrationInfo
*info
)
1049 if (blk_mig_active()) {
1050 info
->has_disk
= true;
1051 info
->disk
= g_malloc0(sizeof(*info
->disk
));
1052 info
->disk
->transferred
= blk_mig_bytes_transferred();
1053 info
->disk
->remaining
= blk_mig_bytes_remaining();
1054 info
->disk
->total
= blk_mig_bytes_total();
1058 static void fill_source_migration_info(MigrationInfo
*info
)
1060 MigrationState
*s
= migrate_get_current();
1062 info
->blocked
= migration_is_blocked(NULL
);
1063 info
->has_blocked_reasons
= info
->blocked
;
1064 info
->blocked_reasons
= NULL
;
1065 if (info
->blocked
) {
1066 GSList
*cur_blocker
= migration_blockers
;
1069 * There are two types of reasons a migration might be blocked;
1070 * a) devices marked in VMState as non-migratable, and
1071 * b) Explicit migration blockers
1072 * We need to add both of them here.
1074 qemu_savevm_non_migratable_list(&info
->blocked_reasons
);
1076 while (cur_blocker
) {
1077 QAPI_LIST_PREPEND(info
->blocked_reasons
,
1078 g_strdup(error_get_pretty(cur_blocker
->data
)));
1079 cur_blocker
= g_slist_next(cur_blocker
);
1084 case MIGRATION_STATUS_NONE
:
1085 /* no migration has happened ever */
1086 /* do not overwrite destination migration status */
1088 case MIGRATION_STATUS_SETUP
:
1089 info
->has_status
= true;
1090 info
->has_total_time
= false;
1092 case MIGRATION_STATUS_ACTIVE
:
1093 case MIGRATION_STATUS_CANCELLING
:
1094 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1095 case MIGRATION_STATUS_PRE_SWITCHOVER
:
1096 case MIGRATION_STATUS_DEVICE
:
1097 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1098 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1099 /* TODO add some postcopy stats */
1100 populate_time_info(info
, s
);
1101 populate_ram_info(info
, s
);
1102 populate_disk_info(info
);
1103 populate_vfio_info(info
);
1105 case MIGRATION_STATUS_COLO
:
1106 info
->has_status
= true;
1107 /* TODO: display COLO specific information (checkpoint info etc.) */
1109 case MIGRATION_STATUS_COMPLETED
:
1110 populate_time_info(info
, s
);
1111 populate_ram_info(info
, s
);
1112 populate_vfio_info(info
);
1114 case MIGRATION_STATUS_FAILED
:
1115 info
->has_status
= true;
1117 info
->has_error_desc
= true;
1118 info
->error_desc
= g_strdup(error_get_pretty(s
->error
));
1121 case MIGRATION_STATUS_CANCELLED
:
1122 info
->has_status
= true;
1124 case MIGRATION_STATUS_WAIT_UNPLUG
:
1125 info
->has_status
= true;
1128 info
->status
= s
->state
;
1131 typedef enum WriteTrackingSupport
{
1132 WT_SUPPORT_UNKNOWN
= 0,
1134 WT_SUPPORT_AVAILABLE
,
1135 WT_SUPPORT_COMPATIBLE
1136 } WriteTrackingSupport
;
1139 WriteTrackingSupport
migrate_query_write_tracking(void)
1141 /* Check if kernel supports required UFFD features */
1142 if (!ram_write_tracking_available()) {
1143 return WT_SUPPORT_ABSENT
;
1146 * Check if current memory configuration is
1147 * compatible with required UFFD features.
1149 if (!ram_write_tracking_compatible()) {
1150 return WT_SUPPORT_AVAILABLE
;
1153 return WT_SUPPORT_COMPATIBLE
;
1157 * @migration_caps_check - check capability validity
1159 * @cap_list: old capability list, array of bool
1160 * @params: new capabilities to be applied soon
1161 * @errp: set *errp if the check failed, with reason
1163 * Returns true if check passed, otherwise false.
1165 static bool migrate_caps_check(bool *cap_list
,
1166 MigrationCapabilityStatusList
*params
,
1169 MigrationCapabilityStatusList
*cap
;
1170 bool old_postcopy_cap
;
1171 MigrationIncomingState
*mis
= migration_incoming_get_current();
1173 old_postcopy_cap
= cap_list
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
1175 for (cap
= params
; cap
; cap
= cap
->next
) {
1176 cap_list
[cap
->value
->capability
] = cap
->value
->state
;
1179 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
1180 if (cap_list
[MIGRATION_CAPABILITY_BLOCK
]) {
1181 error_setg(errp
, "QEMU compiled without old-style (blk/-b, inc/-i) "
1183 error_append_hint(errp
, "Use drive_mirror+NBD instead.\n");
1188 #ifndef CONFIG_REPLICATION
1189 if (cap_list
[MIGRATION_CAPABILITY_X_COLO
]) {
1190 error_setg(errp
, "QEMU compiled without replication module"
1191 " can't enable COLO");
1192 error_append_hint(errp
, "Please enable replication before COLO.\n");
1197 if (cap_list
[MIGRATION_CAPABILITY_POSTCOPY_RAM
]) {
1198 /* This check is reasonably expensive, so only when it's being
1199 * set the first time, also it's only the destination that needs
1202 if (!old_postcopy_cap
&& runstate_check(RUN_STATE_INMIGRATE
) &&
1203 !postcopy_ram_supported_by_host(mis
)) {
1204 /* postcopy_ram_supported_by_host will have emitted a more
1207 error_setg(errp
, "Postcopy is not supported");
1211 if (cap_list
[MIGRATION_CAPABILITY_X_IGNORE_SHARED
]) {
1212 error_setg(errp
, "Postcopy is not compatible with ignore-shared");
1217 if (cap_list
[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
]) {
1218 WriteTrackingSupport wt_support
;
1221 * Check if 'background-snapshot' capability is supported by
1222 * host kernel and compatible with guest memory configuration.
1224 wt_support
= migrate_query_write_tracking();
1225 if (wt_support
< WT_SUPPORT_AVAILABLE
) {
1226 error_setg(errp
, "Background-snapshot is not supported by host kernel");
1229 if (wt_support
< WT_SUPPORT_COMPATIBLE
) {
1230 error_setg(errp
, "Background-snapshot is not compatible "
1231 "with guest memory configuration");
1236 * Check if there are any migration capabilities
1237 * incompatible with 'background-snapshot'.
1239 for (idx
= 0; idx
< check_caps_background_snapshot
.size
; idx
++) {
1240 int incomp_cap
= check_caps_background_snapshot
.caps
[idx
];
1241 if (cap_list
[incomp_cap
]) {
1243 "Background-snapshot is not compatible with %s",
1244 MigrationCapability_str(incomp_cap
));
1253 static void fill_destination_migration_info(MigrationInfo
*info
)
1255 MigrationIncomingState
*mis
= migration_incoming_get_current();
1257 if (mis
->socket_address_list
) {
1258 info
->has_socket_address
= true;
1259 info
->socket_address
=
1260 QAPI_CLONE(SocketAddressList
, mis
->socket_address_list
);
1263 switch (mis
->state
) {
1264 case MIGRATION_STATUS_NONE
:
1266 case MIGRATION_STATUS_SETUP
:
1267 case MIGRATION_STATUS_CANCELLING
:
1268 case MIGRATION_STATUS_CANCELLED
:
1269 case MIGRATION_STATUS_ACTIVE
:
1270 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1271 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1272 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1273 case MIGRATION_STATUS_FAILED
:
1274 case MIGRATION_STATUS_COLO
:
1275 info
->has_status
= true;
1277 case MIGRATION_STATUS_COMPLETED
:
1278 info
->has_status
= true;
1279 fill_destination_postcopy_migration_info(info
);
1282 info
->status
= mis
->state
;
1285 MigrationInfo
*qmp_query_migrate(Error
**errp
)
1287 MigrationInfo
*info
= g_malloc0(sizeof(*info
));
1289 fill_destination_migration_info(info
);
1290 fill_source_migration_info(info
);
1295 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList
*params
,
1298 MigrationState
*s
= migrate_get_current();
1299 MigrationCapabilityStatusList
*cap
;
1300 bool cap_list
[MIGRATION_CAPABILITY__MAX
];
1302 if (migration_is_running(s
->state
)) {
1303 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
1307 memcpy(cap_list
, s
->enabled_capabilities
, sizeof(cap_list
));
1308 if (!migrate_caps_check(cap_list
, params
, errp
)) {
1312 for (cap
= params
; cap
; cap
= cap
->next
) {
1313 s
->enabled_capabilities
[cap
->value
->capability
] = cap
->value
->state
;
1318 * Check whether the parameters are valid. Error will be put into errp
1319 * (if provided). Return true if valid, otherwise false.
1321 static bool migrate_params_check(MigrationParameters
*params
, Error
**errp
)
1323 if (params
->has_compress_level
&&
1324 (params
->compress_level
> 9)) {
1325 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "compress_level",
1326 "a value between 0 and 9");
1330 if (params
->has_compress_threads
&& (params
->compress_threads
< 1)) {
1331 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1333 "a value between 1 and 255");
1337 if (params
->has_decompress_threads
&& (params
->decompress_threads
< 1)) {
1338 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1339 "decompress_threads",
1340 "a value between 1 and 255");
1344 if (params
->has_throttle_trigger_threshold
&&
1345 (params
->throttle_trigger_threshold
< 1 ||
1346 params
->throttle_trigger_threshold
> 100)) {
1347 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1348 "throttle_trigger_threshold",
1349 "an integer in the range of 1 to 100");
1353 if (params
->has_cpu_throttle_initial
&&
1354 (params
->cpu_throttle_initial
< 1 ||
1355 params
->cpu_throttle_initial
> 99)) {
1356 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1357 "cpu_throttle_initial",
1358 "an integer in the range of 1 to 99");
1362 if (params
->has_cpu_throttle_increment
&&
1363 (params
->cpu_throttle_increment
< 1 ||
1364 params
->cpu_throttle_increment
> 99)) {
1365 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1366 "cpu_throttle_increment",
1367 "an integer in the range of 1 to 99");
1371 if (params
->has_max_bandwidth
&& (params
->max_bandwidth
> SIZE_MAX
)) {
1372 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1374 "an integer in the range of 0 to "stringify(SIZE_MAX
)
1379 if (params
->has_downtime_limit
&&
1380 (params
->downtime_limit
> MAX_MIGRATE_DOWNTIME
)) {
1381 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1383 "an integer in the range of 0 to "
1384 stringify(MAX_MIGRATE_DOWNTIME
)" ms");
1388 /* x_checkpoint_delay is now always positive */
1390 if (params
->has_multifd_channels
&& (params
->multifd_channels
< 1)) {
1391 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1393 "a value between 1 and 255");
1397 if (params
->has_multifd_zlib_level
&&
1398 (params
->multifd_zlib_level
> 9)) {
1399 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "multifd_zlib_level",
1400 "a value between 0 and 9");
1404 if (params
->has_multifd_zstd_level
&&
1405 (params
->multifd_zstd_level
> 20)) {
1406 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "multifd_zstd_level",
1407 "a value between 0 and 20");
1411 if (params
->has_xbzrle_cache_size
&&
1412 (params
->xbzrle_cache_size
< qemu_target_page_size() ||
1413 !is_power_of_2(params
->xbzrle_cache_size
))) {
1414 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1415 "xbzrle_cache_size",
1416 "a power of two no less than the target page size");
1420 if (params
->has_max_cpu_throttle
&&
1421 (params
->max_cpu_throttle
< params
->cpu_throttle_initial
||
1422 params
->max_cpu_throttle
> 99)) {
1423 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1425 "an integer in the range of cpu_throttle_initial to 99");
1429 if (params
->has_announce_initial
&&
1430 params
->announce_initial
> 100000) {
1431 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1433 "a value between 0 and 100000");
1436 if (params
->has_announce_max
&&
1437 params
->announce_max
> 100000) {
1438 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1440 "a value between 0 and 100000");
1443 if (params
->has_announce_rounds
&&
1444 params
->announce_rounds
> 1000) {
1445 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1447 "a value between 0 and 1000");
1450 if (params
->has_announce_step
&&
1451 (params
->announce_step
< 1 ||
1452 params
->announce_step
> 10000)) {
1453 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1455 "a value between 0 and 10000");
1459 if (params
->has_block_bitmap_mapping
&&
1460 !check_dirty_bitmap_mig_alias_map(params
->block_bitmap_mapping
, errp
)) {
1461 error_prepend(errp
, "Invalid mapping given for block-bitmap-mapping: ");
1468 static void migrate_params_test_apply(MigrateSetParameters
*params
,
1469 MigrationParameters
*dest
)
1471 *dest
= migrate_get_current()->parameters
;
1473 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1475 if (params
->has_compress_level
) {
1476 dest
->compress_level
= params
->compress_level
;
1479 if (params
->has_compress_threads
) {
1480 dest
->compress_threads
= params
->compress_threads
;
1483 if (params
->has_compress_wait_thread
) {
1484 dest
->compress_wait_thread
= params
->compress_wait_thread
;
1487 if (params
->has_decompress_threads
) {
1488 dest
->decompress_threads
= params
->decompress_threads
;
1491 if (params
->has_throttle_trigger_threshold
) {
1492 dest
->throttle_trigger_threshold
= params
->throttle_trigger_threshold
;
1495 if (params
->has_cpu_throttle_initial
) {
1496 dest
->cpu_throttle_initial
= params
->cpu_throttle_initial
;
1499 if (params
->has_cpu_throttle_increment
) {
1500 dest
->cpu_throttle_increment
= params
->cpu_throttle_increment
;
1503 if (params
->has_cpu_throttle_tailslow
) {
1504 dest
->cpu_throttle_tailslow
= params
->cpu_throttle_tailslow
;
1507 if (params
->has_tls_creds
) {
1508 assert(params
->tls_creds
->type
== QTYPE_QSTRING
);
1509 dest
->tls_creds
= params
->tls_creds
->u
.s
;
1512 if (params
->has_tls_hostname
) {
1513 assert(params
->tls_hostname
->type
== QTYPE_QSTRING
);
1514 dest
->tls_hostname
= params
->tls_hostname
->u
.s
;
1517 if (params
->has_max_bandwidth
) {
1518 dest
->max_bandwidth
= params
->max_bandwidth
;
1521 if (params
->has_downtime_limit
) {
1522 dest
->downtime_limit
= params
->downtime_limit
;
1525 if (params
->has_x_checkpoint_delay
) {
1526 dest
->x_checkpoint_delay
= params
->x_checkpoint_delay
;
1529 if (params
->has_block_incremental
) {
1530 dest
->block_incremental
= params
->block_incremental
;
1532 if (params
->has_multifd_channels
) {
1533 dest
->multifd_channels
= params
->multifd_channels
;
1535 if (params
->has_multifd_compression
) {
1536 dest
->multifd_compression
= params
->multifd_compression
;
1538 if (params
->has_xbzrle_cache_size
) {
1539 dest
->xbzrle_cache_size
= params
->xbzrle_cache_size
;
1541 if (params
->has_max_postcopy_bandwidth
) {
1542 dest
->max_postcopy_bandwidth
= params
->max_postcopy_bandwidth
;
1544 if (params
->has_max_cpu_throttle
) {
1545 dest
->max_cpu_throttle
= params
->max_cpu_throttle
;
1547 if (params
->has_announce_initial
) {
1548 dest
->announce_initial
= params
->announce_initial
;
1550 if (params
->has_announce_max
) {
1551 dest
->announce_max
= params
->announce_max
;
1553 if (params
->has_announce_rounds
) {
1554 dest
->announce_rounds
= params
->announce_rounds
;
1556 if (params
->has_announce_step
) {
1557 dest
->announce_step
= params
->announce_step
;
1560 if (params
->has_block_bitmap_mapping
) {
1561 dest
->has_block_bitmap_mapping
= true;
1562 dest
->block_bitmap_mapping
= params
->block_bitmap_mapping
;
1566 static void migrate_params_apply(MigrateSetParameters
*params
, Error
**errp
)
1568 MigrationState
*s
= migrate_get_current();
1570 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1572 if (params
->has_compress_level
) {
1573 s
->parameters
.compress_level
= params
->compress_level
;
1576 if (params
->has_compress_threads
) {
1577 s
->parameters
.compress_threads
= params
->compress_threads
;
1580 if (params
->has_compress_wait_thread
) {
1581 s
->parameters
.compress_wait_thread
= params
->compress_wait_thread
;
1584 if (params
->has_decompress_threads
) {
1585 s
->parameters
.decompress_threads
= params
->decompress_threads
;
1588 if (params
->has_throttle_trigger_threshold
) {
1589 s
->parameters
.throttle_trigger_threshold
= params
->throttle_trigger_threshold
;
1592 if (params
->has_cpu_throttle_initial
) {
1593 s
->parameters
.cpu_throttle_initial
= params
->cpu_throttle_initial
;
1596 if (params
->has_cpu_throttle_increment
) {
1597 s
->parameters
.cpu_throttle_increment
= params
->cpu_throttle_increment
;
1600 if (params
->has_cpu_throttle_tailslow
) {
1601 s
->parameters
.cpu_throttle_tailslow
= params
->cpu_throttle_tailslow
;
1604 if (params
->has_tls_creds
) {
1605 g_free(s
->parameters
.tls_creds
);
1606 assert(params
->tls_creds
->type
== QTYPE_QSTRING
);
1607 s
->parameters
.tls_creds
= g_strdup(params
->tls_creds
->u
.s
);
1610 if (params
->has_tls_hostname
) {
1611 g_free(s
->parameters
.tls_hostname
);
1612 assert(params
->tls_hostname
->type
== QTYPE_QSTRING
);
1613 s
->parameters
.tls_hostname
= g_strdup(params
->tls_hostname
->u
.s
);
1616 if (params
->has_tls_authz
) {
1617 g_free(s
->parameters
.tls_authz
);
1618 assert(params
->tls_authz
->type
== QTYPE_QSTRING
);
1619 s
->parameters
.tls_authz
= g_strdup(params
->tls_authz
->u
.s
);
1622 if (params
->has_max_bandwidth
) {
1623 s
->parameters
.max_bandwidth
= params
->max_bandwidth
;
1624 if (s
->to_dst_file
&& !migration_in_postcopy()) {
1625 qemu_file_set_rate_limit(s
->to_dst_file
,
1626 s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
);
1630 if (params
->has_downtime_limit
) {
1631 s
->parameters
.downtime_limit
= params
->downtime_limit
;
1634 if (params
->has_x_checkpoint_delay
) {
1635 s
->parameters
.x_checkpoint_delay
= params
->x_checkpoint_delay
;
1636 if (migration_in_colo_state()) {
1637 colo_checkpoint_notify(s
);
1641 if (params
->has_block_incremental
) {
1642 s
->parameters
.block_incremental
= params
->block_incremental
;
1644 if (params
->has_multifd_channels
) {
1645 s
->parameters
.multifd_channels
= params
->multifd_channels
;
1647 if (params
->has_multifd_compression
) {
1648 s
->parameters
.multifd_compression
= params
->multifd_compression
;
1650 if (params
->has_xbzrle_cache_size
) {
1651 s
->parameters
.xbzrle_cache_size
= params
->xbzrle_cache_size
;
1652 xbzrle_cache_resize(params
->xbzrle_cache_size
, errp
);
1654 if (params
->has_max_postcopy_bandwidth
) {
1655 s
->parameters
.max_postcopy_bandwidth
= params
->max_postcopy_bandwidth
;
1656 if (s
->to_dst_file
&& migration_in_postcopy()) {
1657 qemu_file_set_rate_limit(s
->to_dst_file
,
1658 s
->parameters
.max_postcopy_bandwidth
/ XFER_LIMIT_RATIO
);
1661 if (params
->has_max_cpu_throttle
) {
1662 s
->parameters
.max_cpu_throttle
= params
->max_cpu_throttle
;
1664 if (params
->has_announce_initial
) {
1665 s
->parameters
.announce_initial
= params
->announce_initial
;
1667 if (params
->has_announce_max
) {
1668 s
->parameters
.announce_max
= params
->announce_max
;
1670 if (params
->has_announce_rounds
) {
1671 s
->parameters
.announce_rounds
= params
->announce_rounds
;
1673 if (params
->has_announce_step
) {
1674 s
->parameters
.announce_step
= params
->announce_step
;
1677 if (params
->has_block_bitmap_mapping
) {
1678 qapi_free_BitmapMigrationNodeAliasList(
1679 s
->parameters
.block_bitmap_mapping
);
1681 s
->parameters
.has_block_bitmap_mapping
= true;
1682 s
->parameters
.block_bitmap_mapping
=
1683 QAPI_CLONE(BitmapMigrationNodeAliasList
,
1684 params
->block_bitmap_mapping
);
1688 void qmp_migrate_set_parameters(MigrateSetParameters
*params
, Error
**errp
)
1690 MigrationParameters tmp
;
1692 /* TODO Rewrite "" to null instead */
1693 if (params
->has_tls_creds
1694 && params
->tls_creds
->type
== QTYPE_QNULL
) {
1695 qobject_unref(params
->tls_creds
->u
.n
);
1696 params
->tls_creds
->type
= QTYPE_QSTRING
;
1697 params
->tls_creds
->u
.s
= strdup("");
1699 /* TODO Rewrite "" to null instead */
1700 if (params
->has_tls_hostname
1701 && params
->tls_hostname
->type
== QTYPE_QNULL
) {
1702 qobject_unref(params
->tls_hostname
->u
.n
);
1703 params
->tls_hostname
->type
= QTYPE_QSTRING
;
1704 params
->tls_hostname
->u
.s
= strdup("");
1707 migrate_params_test_apply(params
, &tmp
);
1709 if (!migrate_params_check(&tmp
, errp
)) {
1710 /* Invalid parameter */
1714 migrate_params_apply(params
, errp
);
1718 void qmp_migrate_start_postcopy(Error
**errp
)
1720 MigrationState
*s
= migrate_get_current();
1722 if (!migrate_postcopy()) {
1723 error_setg(errp
, "Enable postcopy with migrate_set_capability before"
1724 " the start of migration");
1728 if (s
->state
== MIGRATION_STATUS_NONE
) {
1729 error_setg(errp
, "Postcopy must be started after migration has been"
1734 * we don't error if migration has finished since that would be racy
1735 * with issuing this command.
1737 qatomic_set(&s
->start_postcopy
, true);
1740 /* shared migration helpers */
1742 void migrate_set_state(int *state
, int old_state
, int new_state
)
1744 assert(new_state
< MIGRATION_STATUS__MAX
);
1745 if (qatomic_cmpxchg(state
, old_state
, new_state
) == old_state
) {
1746 trace_migrate_set_state(MigrationStatus_str(new_state
));
1747 migrate_generate_event(new_state
);
1751 static MigrationCapabilityStatus
*migrate_cap_add(MigrationCapability index
,
1754 MigrationCapabilityStatus
*cap
;
1756 cap
= g_new0(MigrationCapabilityStatus
, 1);
1757 cap
->capability
= index
;
1763 void migrate_set_block_enabled(bool value
, Error
**errp
)
1765 MigrationCapabilityStatusList
*cap
= NULL
;
1767 QAPI_LIST_PREPEND(cap
, migrate_cap_add(MIGRATION_CAPABILITY_BLOCK
, value
));
1768 qmp_migrate_set_capabilities(cap
, errp
);
1769 qapi_free_MigrationCapabilityStatusList(cap
);
1772 static void migrate_set_block_incremental(MigrationState
*s
, bool value
)
1774 s
->parameters
.block_incremental
= value
;
1777 static void block_cleanup_parameters(MigrationState
*s
)
1779 if (s
->must_remove_block_options
) {
1780 /* setting to false can never fail */
1781 migrate_set_block_enabled(false, &error_abort
);
1782 migrate_set_block_incremental(s
, false);
1783 s
->must_remove_block_options
= false;
1787 static void migrate_fd_cleanup(MigrationState
*s
)
1789 qemu_bh_delete(s
->cleanup_bh
);
1790 s
->cleanup_bh
= NULL
;
1792 qemu_savevm_state_cleanup();
1794 if (s
->to_dst_file
) {
1797 trace_migrate_fd_cleanup();
1798 qemu_mutex_unlock_iothread();
1799 if (s
->migration_thread_running
) {
1800 qemu_thread_join(&s
->thread
);
1801 s
->migration_thread_running
= false;
1803 qemu_mutex_lock_iothread();
1805 multifd_save_cleanup();
1806 qemu_mutex_lock(&s
->qemu_file_lock
);
1807 tmp
= s
->to_dst_file
;
1808 s
->to_dst_file
= NULL
;
1809 qemu_mutex_unlock(&s
->qemu_file_lock
);
1811 * Close the file handle without the lock to make sure the
1812 * critical section won't block for long.
1817 assert(!migration_is_active(s
));
1819 if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
1820 migrate_set_state(&s
->state
, MIGRATION_STATUS_CANCELLING
,
1821 MIGRATION_STATUS_CANCELLED
);
1825 /* It is used on info migrate. We can't free it */
1826 error_report_err(error_copy(s
->error
));
1828 notifier_list_notify(&migration_state_notifiers
, s
);
1829 block_cleanup_parameters(s
);
1830 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
1833 static void migrate_fd_cleanup_schedule(MigrationState
*s
)
1836 * Ref the state for bh, because it may be called when
1837 * there're already no other refs
1839 object_ref(OBJECT(s
));
1840 qemu_bh_schedule(s
->cleanup_bh
);
1843 static void migrate_fd_cleanup_bh(void *opaque
)
1845 MigrationState
*s
= opaque
;
1846 migrate_fd_cleanup(s
);
1847 object_unref(OBJECT(s
));
1850 void migrate_set_error(MigrationState
*s
, const Error
*error
)
1852 QEMU_LOCK_GUARD(&s
->error_mutex
);
1854 s
->error
= error_copy(error
);
1858 void migrate_fd_error(MigrationState
*s
, const Error
*error
)
1860 trace_migrate_fd_error(error_get_pretty(error
));
1861 assert(s
->to_dst_file
== NULL
);
1862 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1863 MIGRATION_STATUS_FAILED
);
1864 migrate_set_error(s
, error
);
1867 static void migrate_fd_cancel(MigrationState
*s
)
1870 QEMUFile
*f
= migrate_get_current()->to_dst_file
;
1871 trace_migrate_fd_cancel();
1873 if (s
->rp_state
.from_dst_file
) {
1874 /* shutdown the rp socket, so causing the rp thread to shutdown */
1875 qemu_file_shutdown(s
->rp_state
.from_dst_file
);
1879 old_state
= s
->state
;
1880 if (!migration_is_running(old_state
)) {
1883 /* If the migration is paused, kick it out of the pause */
1884 if (old_state
== MIGRATION_STATUS_PRE_SWITCHOVER
) {
1885 qemu_sem_post(&s
->pause_sem
);
1887 migrate_set_state(&s
->state
, old_state
, MIGRATION_STATUS_CANCELLING
);
1888 } while (s
->state
!= MIGRATION_STATUS_CANCELLING
);
1891 * If we're unlucky the migration code might be stuck somewhere in a
1892 * send/write while the network has failed and is waiting to timeout;
1893 * if we've got shutdown(2) available then we can force it to quit.
1894 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1895 * called in a bh, so there is no race against this cancel.
1897 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& f
) {
1898 qemu_file_shutdown(f
);
1900 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& s
->block_inactive
) {
1901 Error
*local_err
= NULL
;
1903 bdrv_invalidate_cache_all(&local_err
);
1905 error_report_err(local_err
);
1907 s
->block_inactive
= false;
1912 void add_migration_state_change_notifier(Notifier
*notify
)
1914 notifier_list_add(&migration_state_notifiers
, notify
);
1917 void remove_migration_state_change_notifier(Notifier
*notify
)
1919 notifier_remove(notify
);
1922 bool migration_in_setup(MigrationState
*s
)
1924 return s
->state
== MIGRATION_STATUS_SETUP
;
1927 bool migration_has_finished(MigrationState
*s
)
1929 return s
->state
== MIGRATION_STATUS_COMPLETED
;
1932 bool migration_has_failed(MigrationState
*s
)
1934 return (s
->state
== MIGRATION_STATUS_CANCELLED
||
1935 s
->state
== MIGRATION_STATUS_FAILED
);
1938 bool migration_in_postcopy(void)
1940 MigrationState
*s
= migrate_get_current();
1943 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1944 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1945 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1952 bool migration_in_postcopy_after_devices(MigrationState
*s
)
1954 return migration_in_postcopy() && s
->postcopy_after_devices
;
1957 bool migration_in_incoming_postcopy(void)
1959 PostcopyState ps
= postcopy_state_get();
1961 return ps
>= POSTCOPY_INCOMING_DISCARD
&& ps
< POSTCOPY_INCOMING_END
;
1964 bool migration_in_bg_snapshot(void)
1966 MigrationState
*s
= migrate_get_current();
1968 return migrate_background_snapshot() &&
1969 migration_is_setup_or_active(s
->state
);
1972 bool migration_is_idle(void)
1974 MigrationState
*s
= current_migration
;
1981 case MIGRATION_STATUS_NONE
:
1982 case MIGRATION_STATUS_CANCELLED
:
1983 case MIGRATION_STATUS_COMPLETED
:
1984 case MIGRATION_STATUS_FAILED
:
1986 case MIGRATION_STATUS_SETUP
:
1987 case MIGRATION_STATUS_CANCELLING
:
1988 case MIGRATION_STATUS_ACTIVE
:
1989 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1990 case MIGRATION_STATUS_COLO
:
1991 case MIGRATION_STATUS_PRE_SWITCHOVER
:
1992 case MIGRATION_STATUS_DEVICE
:
1993 case MIGRATION_STATUS_WAIT_UNPLUG
:
1995 case MIGRATION_STATUS__MAX
:
1996 g_assert_not_reached();
2002 bool migration_is_active(MigrationState
*s
)
2004 return (s
->state
== MIGRATION_STATUS_ACTIVE
||
2005 s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2008 void migrate_init(MigrationState
*s
)
2011 * Reinitialise all migration state, except
2012 * parameters/capabilities that the user set, and
2017 s
->to_dst_file
= NULL
;
2018 s
->state
= MIGRATION_STATUS_NONE
;
2019 s
->rp_state
.from_dst_file
= NULL
;
2020 s
->rp_state
.error
= false;
2022 s
->pages_per_second
= 0.0;
2024 s
->expected_downtime
= 0;
2026 s
->start_postcopy
= false;
2027 s
->postcopy_after_devices
= false;
2028 s
->migration_thread_running
= false;
2029 error_free(s
->error
);
2033 migrate_set_state(&s
->state
, MIGRATION_STATUS_NONE
, MIGRATION_STATUS_SETUP
);
2035 s
->start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
2037 s
->vm_was_running
= false;
2038 s
->iteration_initial_bytes
= 0;
2039 s
->threshold_size
= 0;
2042 int migrate_add_blocker(Error
*reason
, Error
**errp
)
2044 if (only_migratable
) {
2045 error_propagate_prepend(errp
, error_copy(reason
),
2046 "disallowing migration blocker "
2047 "(--only-migratable) for: ");
2051 if (migration_is_idle()) {
2052 migration_blockers
= g_slist_prepend(migration_blockers
, reason
);
2056 error_propagate_prepend(errp
, error_copy(reason
),
2057 "disallowing migration blocker "
2058 "(migration in progress) for: ");
2062 void migrate_del_blocker(Error
*reason
)
2064 migration_blockers
= g_slist_remove(migration_blockers
, reason
);
2067 void qmp_migrate_incoming(const char *uri
, Error
**errp
)
2069 Error
*local_err
= NULL
;
2070 static bool once
= true;
2073 error_setg(errp
, "The incoming migration has already been started");
2076 if (!runstate_check(RUN_STATE_INMIGRATE
)) {
2077 error_setg(errp
, "'-incoming' was not specified on the command line");
2081 qemu_start_incoming_migration(uri
, &local_err
);
2084 error_propagate(errp
, local_err
);
2091 void qmp_migrate_recover(const char *uri
, Error
**errp
)
2093 MigrationIncomingState
*mis
= migration_incoming_get_current();
2095 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2096 error_setg(errp
, "Migrate recover can only be run "
2097 "when postcopy is paused.");
2101 if (qatomic_cmpxchg(&mis
->postcopy_recover_triggered
,
2102 false, true) == true) {
2103 error_setg(errp
, "Migrate recovery is triggered already");
2108 * Note that this call will never start a real migration; it will
2109 * only re-setup the migration stream and poke existing migration
2110 * to continue using that newly established channel.
2112 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2113 qemu_start_incoming_migration(uri
, errp
);
2116 void qmp_migrate_pause(Error
**errp
)
2118 MigrationState
*ms
= migrate_get_current();
2119 MigrationIncomingState
*mis
= migration_incoming_get_current();
2122 if (ms
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
2123 /* Source side, during postcopy */
2124 qemu_mutex_lock(&ms
->qemu_file_lock
);
2125 ret
= qemu_file_shutdown(ms
->to_dst_file
);
2126 qemu_mutex_unlock(&ms
->qemu_file_lock
);
2128 error_setg(errp
, "Failed to pause source migration");
2133 if (mis
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
2134 ret
= qemu_file_shutdown(mis
->from_src_file
);
2136 error_setg(errp
, "Failed to pause destination migration");
2141 error_setg(errp
, "migrate-pause is currently only supported "
2142 "during postcopy-active state");
2145 bool migration_is_blocked(Error
**errp
)
2147 if (qemu_savevm_state_blocked(errp
)) {
2151 if (migration_blockers
) {
2152 error_propagate(errp
, error_copy(migration_blockers
->data
));
2159 /* Returns true if continue to migrate, or false if error detected */
2160 static bool migrate_prepare(MigrationState
*s
, bool blk
, bool blk_inc
,
2161 bool resume
, Error
**errp
)
2163 Error
*local_err
= NULL
;
2166 if (s
->state
!= MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2167 error_setg(errp
, "Cannot resume if there is no "
2168 "paused migration");
2173 * Postcopy recovery won't work well with release-ram
2174 * capability since release-ram will drop the page buffer as
2175 * long as the page is put into the send buffer. So if there
2176 * is a network failure happened, any page buffers that have
2177 * not yet reached the destination VM but have already been
2178 * sent from the source VM will be lost forever. Let's refuse
2179 * the client from resuming such a postcopy migration.
2180 * Luckily release-ram was designed to only be used when src
2181 * and destination VMs are on the same host, so it should be
2184 if (migrate_release_ram()) {
2185 error_setg(errp
, "Postcopy recovery cannot work "
2186 "when release-ram capability is set");
2190 /* This is a resume, skip init status */
2194 if (migration_is_running(s
->state
)) {
2195 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
2199 if (runstate_check(RUN_STATE_INMIGRATE
)) {
2200 error_setg(errp
, "Guest is waiting for an incoming migration");
2204 if (runstate_check(RUN_STATE_POSTMIGRATE
)) {
2205 error_setg(errp
, "Can't migrate the vm that was paused due to "
2206 "previous migration");
2210 if (migration_is_blocked(errp
)) {
2214 if (blk
|| blk_inc
) {
2215 if (migrate_use_block() || migrate_use_block_incremental()) {
2216 error_setg(errp
, "Command options are incompatible with "
2217 "current migration capabilities");
2220 migrate_set_block_enabled(true, &local_err
);
2222 error_propagate(errp
, local_err
);
2225 s
->must_remove_block_options
= true;
2229 migrate_set_block_incremental(s
, true);
2234 * set ram_counters memory to zero for a
2237 memset(&ram_counters
, 0, sizeof(ram_counters
));
2242 void qmp_migrate(const char *uri
, bool has_blk
, bool blk
,
2243 bool has_inc
, bool inc
, bool has_detach
, bool detach
,
2244 bool has_resume
, bool resume
, Error
**errp
)
2246 Error
*local_err
= NULL
;
2247 MigrationState
*s
= migrate_get_current();
2248 const char *p
= NULL
;
2250 if (!migrate_prepare(s
, has_blk
&& blk
, has_inc
&& inc
,
2251 has_resume
&& resume
, errp
)) {
2252 /* Error detected, put into errp */
2256 if (!(has_resume
&& resume
)) {
2257 if (!yank_register_instance(MIGRATION_YANK_INSTANCE
, errp
)) {
2262 if (strstart(uri
, "tcp:", &p
) ||
2263 strstart(uri
, "unix:", NULL
) ||
2264 strstart(uri
, "vsock:", NULL
)) {
2265 socket_start_outgoing_migration(s
, p
? p
: uri
, &local_err
);
2267 } else if (strstart(uri
, "rdma:", &p
)) {
2268 rdma_start_outgoing_migration(s
, p
, &local_err
);
2270 } else if (strstart(uri
, "exec:", &p
)) {
2271 exec_start_outgoing_migration(s
, p
, &local_err
);
2272 } else if (strstart(uri
, "fd:", &p
)) {
2273 fd_start_outgoing_migration(s
, p
, &local_err
);
2275 if (!(has_resume
&& resume
)) {
2276 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2278 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "uri",
2279 "a valid migration protocol");
2280 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
2281 MIGRATION_STATUS_FAILED
);
2282 block_cleanup_parameters(s
);
2287 if (!(has_resume
&& resume
)) {
2288 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2290 migrate_fd_error(s
, local_err
);
2291 error_propagate(errp
, local_err
);
2296 void qmp_migrate_cancel(Error
**errp
)
2298 migrate_fd_cancel(migrate_get_current());
2301 void qmp_migrate_continue(MigrationStatus state
, Error
**errp
)
2303 MigrationState
*s
= migrate_get_current();
2304 if (s
->state
!= state
) {
2305 error_setg(errp
, "Migration not in expected state: %s",
2306 MigrationStatus_str(s
->state
));
2309 qemu_sem_post(&s
->pause_sem
);
2312 bool migrate_release_ram(void)
2316 s
= migrate_get_current();
2318 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_RELEASE_RAM
];
2321 bool migrate_postcopy_ram(void)
2325 s
= migrate_get_current();
2327 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
2330 bool migrate_postcopy(void)
2332 return migrate_postcopy_ram() || migrate_dirty_bitmaps();
2335 bool migrate_auto_converge(void)
2339 s
= migrate_get_current();
2341 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_AUTO_CONVERGE
];
2344 bool migrate_zero_blocks(void)
2348 s
= migrate_get_current();
2350 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_ZERO_BLOCKS
];
2353 bool migrate_postcopy_blocktime(void)
2357 s
= migrate_get_current();
2359 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME
];
2362 bool migrate_use_compression(void)
2366 s
= migrate_get_current();
2368 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_COMPRESS
];
2371 int migrate_compress_level(void)
2375 s
= migrate_get_current();
2377 return s
->parameters
.compress_level
;
2380 int migrate_compress_threads(void)
2384 s
= migrate_get_current();
2386 return s
->parameters
.compress_threads
;
2389 int migrate_compress_wait_thread(void)
2393 s
= migrate_get_current();
2395 return s
->parameters
.compress_wait_thread
;
2398 int migrate_decompress_threads(void)
2402 s
= migrate_get_current();
2404 return s
->parameters
.decompress_threads
;
2407 bool migrate_dirty_bitmaps(void)
2411 s
= migrate_get_current();
2413 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_DIRTY_BITMAPS
];
2416 bool migrate_ignore_shared(void)
2420 s
= migrate_get_current();
2422 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_IGNORE_SHARED
];
2425 bool migrate_validate_uuid(void)
2429 s
= migrate_get_current();
2431 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_VALIDATE_UUID
];
2434 bool migrate_use_events(void)
2438 s
= migrate_get_current();
2440 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_EVENTS
];
2443 bool migrate_use_multifd(void)
2447 s
= migrate_get_current();
2449 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_MULTIFD
];
2452 bool migrate_pause_before_switchover(void)
2456 s
= migrate_get_current();
2458 return s
->enabled_capabilities
[
2459 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER
];
2462 int migrate_multifd_channels(void)
2466 s
= migrate_get_current();
2468 return s
->parameters
.multifd_channels
;
2471 MultiFDCompression
migrate_multifd_compression(void)
2475 s
= migrate_get_current();
2477 return s
->parameters
.multifd_compression
;
2480 int migrate_multifd_zlib_level(void)
2484 s
= migrate_get_current();
2486 return s
->parameters
.multifd_zlib_level
;
2489 int migrate_multifd_zstd_level(void)
2493 s
= migrate_get_current();
2495 return s
->parameters
.multifd_zstd_level
;
2498 int migrate_use_xbzrle(void)
2502 s
= migrate_get_current();
2504 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_XBZRLE
];
2507 uint64_t migrate_xbzrle_cache_size(void)
2511 s
= migrate_get_current();
2513 return s
->parameters
.xbzrle_cache_size
;
2516 static int64_t migrate_max_postcopy_bandwidth(void)
2520 s
= migrate_get_current();
2522 return s
->parameters
.max_postcopy_bandwidth
;
2525 bool migrate_use_block(void)
2529 s
= migrate_get_current();
2531 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_BLOCK
];
2534 bool migrate_use_return_path(void)
2538 s
= migrate_get_current();
2540 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_RETURN_PATH
];
2543 bool migrate_use_block_incremental(void)
2547 s
= migrate_get_current();
2549 return s
->parameters
.block_incremental
;
2552 bool migrate_background_snapshot(void)
2556 s
= migrate_get_current();
2558 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
];
2561 /* migration thread support */
2563 * Something bad happened to the RP stream, mark an error
2564 * The caller shall print or trace something to indicate why
2566 static void mark_source_rp_bad(MigrationState
*s
)
2568 s
->rp_state
.error
= true;
2571 static struct rp_cmd_args
{
2572 ssize_t len
; /* -1 = variable */
2575 [MIG_RP_MSG_INVALID
] = { .len
= -1, .name
= "INVALID" },
2576 [MIG_RP_MSG_SHUT
] = { .len
= 4, .name
= "SHUT" },
2577 [MIG_RP_MSG_PONG
] = { .len
= 4, .name
= "PONG" },
2578 [MIG_RP_MSG_REQ_PAGES
] = { .len
= 12, .name
= "REQ_PAGES" },
2579 [MIG_RP_MSG_REQ_PAGES_ID
] = { .len
= -1, .name
= "REQ_PAGES_ID" },
2580 [MIG_RP_MSG_RECV_BITMAP
] = { .len
= -1, .name
= "RECV_BITMAP" },
2581 [MIG_RP_MSG_RESUME_ACK
] = { .len
= 4, .name
= "RESUME_ACK" },
2582 [MIG_RP_MSG_MAX
] = { .len
= -1, .name
= "MAX" },
2586 * Process a request for pages received on the return path,
2587 * We're allowed to send more than requested (e.g. to round to our page size)
2588 * and we don't need to send pages that have already been sent.
2590 static void migrate_handle_rp_req_pages(MigrationState
*ms
, const char* rbname
,
2591 ram_addr_t start
, size_t len
)
2593 long our_host_ps
= qemu_real_host_page_size
;
2595 trace_migrate_handle_rp_req_pages(rbname
, start
, len
);
2598 * Since we currently insist on matching page sizes, just sanity check
2599 * we're being asked for whole host pages.
2601 if (start
& (our_host_ps
- 1) ||
2602 (len
& (our_host_ps
- 1))) {
2603 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
2604 " len: %zd", __func__
, start
, len
);
2605 mark_source_rp_bad(ms
);
2609 if (ram_save_queue_pages(rbname
, start
, len
)) {
2610 mark_source_rp_bad(ms
);
2614 /* Return true to retry, false to quit */
2615 static bool postcopy_pause_return_path_thread(MigrationState
*s
)
2617 trace_postcopy_pause_return_path();
2619 qemu_sem_wait(&s
->postcopy_pause_rp_sem
);
2621 trace_postcopy_pause_return_path_continued();
2626 static int migrate_handle_rp_recv_bitmap(MigrationState
*s
, char *block_name
)
2628 RAMBlock
*block
= qemu_ram_block_by_name(block_name
);
2631 error_report("%s: invalid block name '%s'", __func__
, block_name
);
2635 /* Fetch the received bitmap and refresh the dirty bitmap */
2636 return ram_dirty_bitmap_reload(s
, block
);
2639 static int migrate_handle_rp_resume_ack(MigrationState
*s
, uint32_t value
)
2641 trace_source_return_path_thread_resume_ack(value
);
2643 if (value
!= MIGRATION_RESUME_ACK_VALUE
) {
2644 error_report("%s: illegal resume_ack value %"PRIu32
,
2649 /* Now both sides are active. */
2650 migrate_set_state(&s
->state
, MIGRATION_STATUS_POSTCOPY_RECOVER
,
2651 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2653 /* Notify send thread that time to continue send pages */
2654 qemu_sem_post(&s
->rp_state
.rp_sem
);
2660 * Handles messages sent on the return path towards the source VM
2663 static void *source_return_path_thread(void *opaque
)
2665 MigrationState
*ms
= opaque
;
2666 QEMUFile
*rp
= ms
->rp_state
.from_dst_file
;
2667 uint16_t header_len
, header_type
;
2669 uint32_t tmp32
, sibling_error
;
2670 ram_addr_t start
= 0; /* =0 to silence warning */
2671 size_t len
= 0, expected_len
;
2674 trace_source_return_path_thread_entry();
2675 rcu_register_thread();
2678 while (!ms
->rp_state
.error
&& !qemu_file_get_error(rp
) &&
2679 migration_is_setup_or_active(ms
->state
)) {
2680 trace_source_return_path_thread_loop_top();
2681 header_type
= qemu_get_be16(rp
);
2682 header_len
= qemu_get_be16(rp
);
2684 if (qemu_file_get_error(rp
)) {
2685 mark_source_rp_bad(ms
);
2689 if (header_type
>= MIG_RP_MSG_MAX
||
2690 header_type
== MIG_RP_MSG_INVALID
) {
2691 error_report("RP: Received invalid message 0x%04x length 0x%04x",
2692 header_type
, header_len
);
2693 mark_source_rp_bad(ms
);
2697 if ((rp_cmd_args
[header_type
].len
!= -1 &&
2698 header_len
!= rp_cmd_args
[header_type
].len
) ||
2699 header_len
> sizeof(buf
)) {
2700 error_report("RP: Received '%s' message (0x%04x) with"
2701 "incorrect length %d expecting %zu",
2702 rp_cmd_args
[header_type
].name
, header_type
, header_len
,
2703 (size_t)rp_cmd_args
[header_type
].len
);
2704 mark_source_rp_bad(ms
);
2708 /* We know we've got a valid header by this point */
2709 res
= qemu_get_buffer(rp
, buf
, header_len
);
2710 if (res
!= header_len
) {
2711 error_report("RP: Failed reading data for message 0x%04x"
2712 " read %d expected %d",
2713 header_type
, res
, header_len
);
2714 mark_source_rp_bad(ms
);
2718 /* OK, we have the message and the data */
2719 switch (header_type
) {
2720 case MIG_RP_MSG_SHUT
:
2721 sibling_error
= ldl_be_p(buf
);
2722 trace_source_return_path_thread_shut(sibling_error
);
2723 if (sibling_error
) {
2724 error_report("RP: Sibling indicated error %d", sibling_error
);
2725 mark_source_rp_bad(ms
);
2728 * We'll let the main thread deal with closing the RP
2729 * we could do a shutdown(2) on it, but we're the only user
2730 * anyway, so there's nothing gained.
2734 case MIG_RP_MSG_PONG
:
2735 tmp32
= ldl_be_p(buf
);
2736 trace_source_return_path_thread_pong(tmp32
);
2739 case MIG_RP_MSG_REQ_PAGES
:
2740 start
= ldq_be_p(buf
);
2741 len
= ldl_be_p(buf
+ 8);
2742 migrate_handle_rp_req_pages(ms
, NULL
, start
, len
);
2745 case MIG_RP_MSG_REQ_PAGES_ID
:
2746 expected_len
= 12 + 1; /* header + termination */
2748 if (header_len
>= expected_len
) {
2749 start
= ldq_be_p(buf
);
2750 len
= ldl_be_p(buf
+ 8);
2751 /* Now we expect an idstr */
2752 tmp32
= buf
[12]; /* Length of the following idstr */
2753 buf
[13 + tmp32
] = '\0';
2754 expected_len
+= tmp32
;
2756 if (header_len
!= expected_len
) {
2757 error_report("RP: Req_Page_id with length %d expecting %zd",
2758 header_len
, expected_len
);
2759 mark_source_rp_bad(ms
);
2762 migrate_handle_rp_req_pages(ms
, (char *)&buf
[13], start
, len
);
2765 case MIG_RP_MSG_RECV_BITMAP
:
2766 if (header_len
< 1) {
2767 error_report("%s: missing block name", __func__
);
2768 mark_source_rp_bad(ms
);
2771 /* Format: len (1B) + idstr (<255B). This ends the idstr. */
2772 buf
[buf
[0] + 1] = '\0';
2773 if (migrate_handle_rp_recv_bitmap(ms
, (char *)(buf
+ 1))) {
2774 mark_source_rp_bad(ms
);
2779 case MIG_RP_MSG_RESUME_ACK
:
2780 tmp32
= ldl_be_p(buf
);
2781 if (migrate_handle_rp_resume_ack(ms
, tmp32
)) {
2782 mark_source_rp_bad(ms
);
2793 res
= qemu_file_get_error(rp
);
2795 if (res
== -EIO
&& migration_in_postcopy()) {
2797 * Maybe there is something we can do: it looks like a
2798 * network down issue, and we pause for a recovery.
2800 if (postcopy_pause_return_path_thread(ms
)) {
2801 /* Reload rp, reset the rest */
2802 if (rp
!= ms
->rp_state
.from_dst_file
) {
2804 rp
= ms
->rp_state
.from_dst_file
;
2806 ms
->rp_state
.error
= false;
2811 trace_source_return_path_thread_bad_end();
2812 mark_source_rp_bad(ms
);
2815 trace_source_return_path_thread_end();
2816 ms
->rp_state
.from_dst_file
= NULL
;
2818 rcu_unregister_thread();
2822 static int open_return_path_on_source(MigrationState
*ms
,
2826 ms
->rp_state
.from_dst_file
= qemu_file_get_return_path(ms
->to_dst_file
);
2827 if (!ms
->rp_state
.from_dst_file
) {
2831 trace_open_return_path_on_source();
2833 if (!create_thread
) {
2838 qemu_thread_create(&ms
->rp_state
.rp_thread
, "return path",
2839 source_return_path_thread
, ms
, QEMU_THREAD_JOINABLE
);
2841 trace_open_return_path_on_source_continue();
2846 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
2847 static int await_return_path_close_on_source(MigrationState
*ms
)
2850 * If this is a normal exit then the destination will send a SHUT and the
2851 * rp_thread will exit, however if there's an error we need to cause
2854 if (qemu_file_get_error(ms
->to_dst_file
) && ms
->rp_state
.from_dst_file
) {
2856 * shutdown(2), if we have it, will cause it to unblock if it's stuck
2857 * waiting for the destination.
2859 qemu_file_shutdown(ms
->rp_state
.from_dst_file
);
2860 mark_source_rp_bad(ms
);
2862 trace_await_return_path_close_on_source_joining();
2863 qemu_thread_join(&ms
->rp_state
.rp_thread
);
2864 trace_await_return_path_close_on_source_close();
2865 return ms
->rp_state
.error
;
2869 * Switch from normal iteration to postcopy
2870 * Returns non-0 on error
2872 static int postcopy_start(MigrationState
*ms
)
2875 QIOChannelBuffer
*bioc
;
2877 int64_t time_at_stop
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
2878 int64_t bandwidth
= migrate_max_postcopy_bandwidth();
2879 bool restart_block
= false;
2880 int cur_state
= MIGRATION_STATUS_ACTIVE
;
2881 if (!migrate_pause_before_switchover()) {
2882 migrate_set_state(&ms
->state
, MIGRATION_STATUS_ACTIVE
,
2883 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2886 trace_postcopy_start();
2887 qemu_mutex_lock_iothread();
2888 trace_postcopy_start_set_run();
2890 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
2891 global_state_store();
2892 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
2897 ret
= migration_maybe_pause(ms
, &cur_state
,
2898 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2903 ret
= bdrv_inactivate_all();
2907 restart_block
= true;
2910 * Cause any non-postcopiable, but iterative devices to
2911 * send out their final data.
2913 qemu_savevm_state_complete_precopy(ms
->to_dst_file
, true, false);
2916 * in Finish migrate and with the io-lock held everything should
2917 * be quiet, but we've potentially still got dirty pages and we
2918 * need to tell the destination to throw any pages it's already received
2921 if (migrate_postcopy_ram()) {
2922 if (ram_postcopy_send_discard_bitmap(ms
)) {
2923 error_report("postcopy send discard bitmap failed");
2929 * send rest of state - note things that are doing postcopy
2930 * will notice we're in POSTCOPY_ACTIVE and not actually
2931 * wrap their state up here
2933 /* 0 max-postcopy-bandwidth means unlimited */
2935 qemu_file_set_rate_limit(ms
->to_dst_file
, INT64_MAX
);
2937 qemu_file_set_rate_limit(ms
->to_dst_file
, bandwidth
/ XFER_LIMIT_RATIO
);
2939 if (migrate_postcopy_ram()) {
2940 /* Ping just for debugging, helps line traces up */
2941 qemu_savevm_send_ping(ms
->to_dst_file
, 2);
2945 * While loading the device state we may trigger page transfer
2946 * requests and the fd must be free to process those, and thus
2947 * the destination must read the whole device state off the fd before
2948 * it starts processing it. Unfortunately the ad-hoc migration format
2949 * doesn't allow the destination to know the size to read without fully
2950 * parsing it through each devices load-state code (especially the open
2951 * coded devices that use get/put).
2952 * So we wrap the device state up in a package with a length at the start;
2953 * to do this we use a qemu_buf to hold the whole of the device state.
2955 bioc
= qio_channel_buffer_new(4096);
2956 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-postcopy-buffer");
2957 fb
= qemu_fopen_channel_output(QIO_CHANNEL(bioc
));
2958 object_unref(OBJECT(bioc
));
2961 * Make sure the receiver can get incoming pages before we send the rest
2964 qemu_savevm_send_postcopy_listen(fb
);
2966 qemu_savevm_state_complete_precopy(fb
, false, false);
2967 if (migrate_postcopy_ram()) {
2968 qemu_savevm_send_ping(fb
, 3);
2971 qemu_savevm_send_postcopy_run(fb
);
2973 /* <><> end of stuff going into the package */
2975 /* Last point of recovery; as soon as we send the package the destination
2976 * can open devices and potentially start running.
2977 * Lets just check again we've not got any errors.
2979 ret
= qemu_file_get_error(ms
->to_dst_file
);
2981 error_report("postcopy_start: Migration stream errored (pre package)");
2985 restart_block
= false;
2987 /* Now send that blob */
2988 if (qemu_savevm_send_packaged(ms
->to_dst_file
, bioc
->data
, bioc
->usage
)) {
2993 /* Send a notify to give a chance for anything that needs to happen
2994 * at the transition to postcopy and after the device state; in particular
2995 * spice needs to trigger a transition now
2997 ms
->postcopy_after_devices
= true;
2998 notifier_list_notify(&migration_state_notifiers
, ms
);
3000 ms
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - time_at_stop
;
3002 qemu_mutex_unlock_iothread();
3004 if (migrate_postcopy_ram()) {
3006 * Although this ping is just for debug, it could potentially be
3007 * used for getting a better measurement of downtime at the source.
3009 qemu_savevm_send_ping(ms
->to_dst_file
, 4);
3012 if (migrate_release_ram()) {
3013 ram_postcopy_migrated_memory_release(ms
);
3016 ret
= qemu_file_get_error(ms
->to_dst_file
);
3018 error_report("postcopy_start: Migration stream errored");
3019 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
3020 MIGRATION_STATUS_FAILED
);
3028 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
3029 MIGRATION_STATUS_FAILED
);
3030 if (restart_block
) {
3031 /* A failure happened early enough that we know the destination hasn't
3032 * accessed block devices, so we're safe to recover.
3034 Error
*local_err
= NULL
;
3036 bdrv_invalidate_cache_all(&local_err
);
3038 error_report_err(local_err
);
3041 qemu_mutex_unlock_iothread();
3046 * migration_maybe_pause: Pause if required to by
3047 * migrate_pause_before_switchover called with the iothread locked
3048 * Returns: 0 on success
3050 static int migration_maybe_pause(MigrationState
*s
,
3051 int *current_active_state
,
3054 if (!migrate_pause_before_switchover()) {
3058 /* Since leaving this state is not atomic with posting the semaphore
3059 * it's possible that someone could have issued multiple migrate_continue
3060 * and the semaphore is incorrectly positive at this point;
3061 * the docs say it's undefined to reinit a semaphore that's already
3062 * init'd, so use timedwait to eat up any existing posts.
3064 while (qemu_sem_timedwait(&s
->pause_sem
, 1) == 0) {
3065 /* This block intentionally left blank */
3069 * If the migration is cancelled when it is in the completion phase,
3070 * the migration state is set to MIGRATION_STATUS_CANCELLING.
3071 * So we don't need to wait a semaphore, otherwise we would always
3072 * wait for the 'pause_sem' semaphore.
3074 if (s
->state
!= MIGRATION_STATUS_CANCELLING
) {
3075 qemu_mutex_unlock_iothread();
3076 migrate_set_state(&s
->state
, *current_active_state
,
3077 MIGRATION_STATUS_PRE_SWITCHOVER
);
3078 qemu_sem_wait(&s
->pause_sem
);
3079 migrate_set_state(&s
->state
, MIGRATION_STATUS_PRE_SWITCHOVER
,
3081 *current_active_state
= new_state
;
3082 qemu_mutex_lock_iothread();
3085 return s
->state
== new_state
? 0 : -EINVAL
;
3089 * migration_completion: Used by migration_thread when there's not much left.
3090 * The caller 'breaks' the loop when this returns.
3092 * @s: Current migration state
3094 static void migration_completion(MigrationState
*s
)
3097 int current_active_state
= s
->state
;
3099 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
3100 qemu_mutex_lock_iothread();
3101 s
->downtime_start
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3102 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
3103 s
->vm_was_running
= runstate_is_running();
3104 ret
= global_state_store();
3107 bool inactivate
= !migrate_colo_enabled();
3108 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
3110 ret
= migration_maybe_pause(s
, ¤t_active_state
,
3111 MIGRATION_STATUS_DEVICE
);
3114 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
3115 ret
= qemu_savevm_state_complete_precopy(s
->to_dst_file
, false,
3118 if (inactivate
&& ret
>= 0) {
3119 s
->block_inactive
= true;
3122 qemu_mutex_unlock_iothread();
3127 } else if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
3128 trace_migration_completion_postcopy_end();
3130 qemu_savevm_state_complete_postcopy(s
->to_dst_file
);
3131 trace_migration_completion_postcopy_end_after_complete();
3132 } else if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
3137 * If rp was opened we must clean up the thread before
3138 * cleaning everything else up (since if there are no failures
3139 * it will wait for the destination to send it's status in
3142 if (s
->rp_state
.from_dst_file
) {
3144 trace_migration_return_path_end_before();
3145 rp_error
= await_return_path_close_on_source(s
);
3146 trace_migration_return_path_end_after(rp_error
);
3148 goto fail_invalidate
;
3152 if (qemu_file_get_error(s
->to_dst_file
)) {
3153 trace_migration_completion_file_err();
3154 goto fail_invalidate
;
3157 if (!migrate_colo_enabled()) {
3158 migrate_set_state(&s
->state
, current_active_state
,
3159 MIGRATION_STATUS_COMPLETED
);
3165 /* If not doing postcopy, vm_start() will be called: let's regain
3166 * control on images.
3168 if (s
->state
== MIGRATION_STATUS_ACTIVE
||
3169 s
->state
== MIGRATION_STATUS_DEVICE
) {
3170 Error
*local_err
= NULL
;
3172 qemu_mutex_lock_iothread();
3173 bdrv_invalidate_cache_all(&local_err
);
3175 error_report_err(local_err
);
3177 s
->block_inactive
= false;
3179 qemu_mutex_unlock_iothread();
3183 migrate_set_state(&s
->state
, current_active_state
,
3184 MIGRATION_STATUS_FAILED
);
3188 * bg_migration_completion: Used by bg_migration_thread when after all the
3189 * RAM has been saved. The caller 'breaks' the loop when this returns.
3191 * @s: Current migration state
3193 static void bg_migration_completion(MigrationState
*s
)
3195 int current_active_state
= s
->state
;
3198 * Stop tracking RAM writes - un-protect memory, un-register UFFD
3199 * memory ranges, flush kernel wait queues and wake up threads
3200 * waiting for write fault to be resolved.
3202 ram_write_tracking_stop();
3204 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
3206 * By this moment we have RAM content saved into the migration stream.
3207 * The next step is to flush the non-RAM content (device state)
3208 * right after the ram content. The device state has been stored into
3209 * the temporary buffer before RAM saving started.
3211 qemu_put_buffer(s
->to_dst_file
, s
->bioc
->data
, s
->bioc
->usage
);
3212 qemu_fflush(s
->to_dst_file
);
3213 } else if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
3217 if (qemu_file_get_error(s
->to_dst_file
)) {
3218 trace_migration_completion_file_err();
3222 migrate_set_state(&s
->state
, current_active_state
,
3223 MIGRATION_STATUS_COMPLETED
);
3227 migrate_set_state(&s
->state
, current_active_state
,
3228 MIGRATION_STATUS_FAILED
);
3231 bool migrate_colo_enabled(void)
3233 MigrationState
*s
= migrate_get_current();
3234 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_COLO
];
3237 typedef enum MigThrError
{
3238 /* No error detected */
3239 MIG_THR_ERR_NONE
= 0,
3240 /* Detected error, but resumed successfully */
3241 MIG_THR_ERR_RECOVERED
= 1,
3242 /* Detected fatal error, need to exit */
3243 MIG_THR_ERR_FATAL
= 2,
3246 static int postcopy_resume_handshake(MigrationState
*s
)
3248 qemu_savevm_send_postcopy_resume(s
->to_dst_file
);
3250 while (s
->state
== MIGRATION_STATUS_POSTCOPY_RECOVER
) {
3251 qemu_sem_wait(&s
->rp_state
.rp_sem
);
3254 if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
3261 /* Return zero if success, or <0 for error */
3262 static int postcopy_do_resume(MigrationState
*s
)
3267 * Call all the resume_prepare() hooks, so that modules can be
3268 * ready for the migration resume.
3270 ret
= qemu_savevm_state_resume_prepare(s
);
3272 error_report("%s: resume_prepare() failure detected: %d",
3278 * Last handshake with destination on the resume (destination will
3279 * switch to postcopy-active afterwards)
3281 ret
= postcopy_resume_handshake(s
);
3283 error_report("%s: handshake failed: %d", __func__
, ret
);
3291 * We don't return until we are in a safe state to continue current
3292 * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
3293 * MIG_THR_ERR_FATAL if unrecovery failure happened.
3295 static MigThrError
postcopy_pause(MigrationState
*s
)
3297 assert(s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
3302 /* Current channel is possibly broken. Release it. */
3303 assert(s
->to_dst_file
);
3304 qemu_mutex_lock(&s
->qemu_file_lock
);
3305 file
= s
->to_dst_file
;
3306 s
->to_dst_file
= NULL
;
3307 qemu_mutex_unlock(&s
->qemu_file_lock
);
3309 qemu_file_shutdown(file
);
3312 migrate_set_state(&s
->state
, s
->state
,
3313 MIGRATION_STATUS_POSTCOPY_PAUSED
);
3315 error_report("Detected IO failure for postcopy. "
3316 "Migration paused.");
3319 * We wait until things fixed up. Then someone will setup the
3320 * status back for us.
3322 while (s
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
3323 qemu_sem_wait(&s
->postcopy_pause_sem
);
3326 if (s
->state
== MIGRATION_STATUS_POSTCOPY_RECOVER
) {
3327 /* Woken up by a recover procedure. Give it a shot */
3330 * Firstly, let's wake up the return path now, with a new
3331 * return path channel.
3333 qemu_sem_post(&s
->postcopy_pause_rp_sem
);
3335 /* Do the resume logic */
3336 if (postcopy_do_resume(s
) == 0) {
3337 /* Let's continue! */
3338 trace_postcopy_pause_continued();
3339 return MIG_THR_ERR_RECOVERED
;
3342 * Something wrong happened during the recovery, let's
3343 * pause again. Pause is always better than throwing
3349 /* This is not right... Time to quit. */
3350 return MIG_THR_ERR_FATAL
;
3355 static MigThrError
migration_detect_error(MigrationState
*s
)
3358 int state
= s
->state
;
3359 Error
*local_error
= NULL
;
3361 if (state
== MIGRATION_STATUS_CANCELLING
||
3362 state
== MIGRATION_STATUS_CANCELLED
) {
3363 /* End the migration, but don't set the state to failed */
3364 return MIG_THR_ERR_FATAL
;
3367 /* Try to detect any file errors */
3368 ret
= qemu_file_get_error_obj(s
->to_dst_file
, &local_error
);
3370 /* Everything is fine */
3371 assert(!local_error
);
3372 return MIG_THR_ERR_NONE
;
3376 migrate_set_error(s
, local_error
);
3377 error_free(local_error
);
3380 if (state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
&& ret
== -EIO
) {
3382 * For postcopy, we allow the network to be down for a
3383 * while. After that, it can be continued by a
3386 return postcopy_pause(s
);
3389 * For precopy (or postcopy with error outside IO), we fail
3392 migrate_set_state(&s
->state
, state
, MIGRATION_STATUS_FAILED
);
3393 trace_migration_thread_file_err();
3395 /* Time to stop the migration, now. */
3396 return MIG_THR_ERR_FATAL
;
3400 /* How many bytes have we transferred since the beginning of the migration */
3401 static uint64_t migration_total_bytes(MigrationState
*s
)
3403 return qemu_ftell(s
->to_dst_file
) + ram_counters
.multifd_bytes
;
3406 static void migration_calculate_complete(MigrationState
*s
)
3408 uint64_t bytes
= migration_total_bytes(s
);
3409 int64_t end_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3410 int64_t transfer_time
;
3412 s
->total_time
= end_time
- s
->start_time
;
3415 * It's still not set, so we are precopy migration. For
3416 * postcopy, downtime is calculated during postcopy_start().
3418 s
->downtime
= end_time
- s
->downtime_start
;
3421 transfer_time
= s
->total_time
- s
->setup_time
;
3422 if (transfer_time
) {
3423 s
->mbps
= ((double) bytes
* 8.0) / transfer_time
/ 1000;
3427 static void update_iteration_initial_status(MigrationState
*s
)
3430 * Update these three fields at the same time to avoid mismatch info lead
3431 * wrong speed calculation.
3433 s
->iteration_start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3434 s
->iteration_initial_bytes
= migration_total_bytes(s
);
3435 s
->iteration_initial_pages
= ram_get_total_transferred_pages();
3438 static void migration_update_counters(MigrationState
*s
,
3439 int64_t current_time
)
3441 uint64_t transferred
, transferred_pages
, time_spent
;
3442 uint64_t current_bytes
; /* bytes transferred since the beginning */
3445 if (current_time
< s
->iteration_start_time
+ BUFFER_DELAY
) {
3449 current_bytes
= migration_total_bytes(s
);
3450 transferred
= current_bytes
- s
->iteration_initial_bytes
;
3451 time_spent
= current_time
- s
->iteration_start_time
;
3452 bandwidth
= (double)transferred
/ time_spent
;
3453 s
->threshold_size
= bandwidth
* s
->parameters
.downtime_limit
;
3455 s
->mbps
= (((double) transferred
* 8.0) /
3456 ((double) time_spent
/ 1000.0)) / 1000.0 / 1000.0;
3458 transferred_pages
= ram_get_total_transferred_pages() -
3459 s
->iteration_initial_pages
;
3460 s
->pages_per_second
= (double) transferred_pages
/
3461 (((double) time_spent
/ 1000.0));
3464 * if we haven't sent anything, we don't want to
3465 * recalculate. 10000 is a small enough number for our purposes
3467 if (ram_counters
.dirty_pages_rate
&& transferred
> 10000) {
3468 s
->expected_downtime
= ram_counters
.remaining
/ bandwidth
;
3471 qemu_file_reset_rate_limit(s
->to_dst_file
);
3473 update_iteration_initial_status(s
);
3475 trace_migrate_transferred(transferred
, time_spent
,
3476 bandwidth
, s
->threshold_size
);
3479 /* Migration thread iteration status */
3481 MIG_ITERATE_RESUME
, /* Resume current iteration */
3482 MIG_ITERATE_SKIP
, /* Skip current iteration */
3483 MIG_ITERATE_BREAK
, /* Break the loop */
3487 * Return true if continue to the next iteration directly, false
3490 static MigIterateState
migration_iteration_run(MigrationState
*s
)
3492 uint64_t pending_size
, pend_pre
, pend_compat
, pend_post
;
3493 bool in_postcopy
= s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
;
3495 qemu_savevm_state_pending(s
->to_dst_file
, s
->threshold_size
, &pend_pre
,
3496 &pend_compat
, &pend_post
);
3497 pending_size
= pend_pre
+ pend_compat
+ pend_post
;
3499 trace_migrate_pending(pending_size
, s
->threshold_size
,
3500 pend_pre
, pend_compat
, pend_post
);
3502 if (pending_size
&& pending_size
>= s
->threshold_size
) {
3503 /* Still a significant amount to transfer */
3504 if (!in_postcopy
&& pend_pre
<= s
->threshold_size
&&
3505 qatomic_read(&s
->start_postcopy
)) {
3506 if (postcopy_start(s
)) {
3507 error_report("%s: postcopy failed to start", __func__
);
3509 return MIG_ITERATE_SKIP
;
3511 /* Just another iteration step */
3512 qemu_savevm_state_iterate(s
->to_dst_file
, in_postcopy
);
3514 trace_migration_thread_low_pending(pending_size
);
3515 migration_completion(s
);
3516 return MIG_ITERATE_BREAK
;
3519 return MIG_ITERATE_RESUME
;
3522 static void migration_iteration_finish(MigrationState
*s
)
3524 /* If we enabled cpu throttling for auto-converge, turn it off. */
3525 cpu_throttle_stop();
3527 qemu_mutex_lock_iothread();
3529 case MIGRATION_STATUS_COMPLETED
:
3530 migration_calculate_complete(s
);
3531 runstate_set(RUN_STATE_POSTMIGRATE
);
3534 case MIGRATION_STATUS_ACTIVE
:
3536 * We should really assert here, but since it's during
3537 * migration, let's try to reduce the usage of assertions.
3539 if (!migrate_colo_enabled()) {
3540 error_report("%s: critical error: calling COLO code without "
3541 "COLO enabled", __func__
);
3543 migrate_start_colo_process(s
);
3545 * Fixme: we will run VM in COLO no matter its old running state.
3546 * After exited COLO, we will keep running.
3548 s
->vm_was_running
= true;
3550 case MIGRATION_STATUS_FAILED
:
3551 case MIGRATION_STATUS_CANCELLED
:
3552 case MIGRATION_STATUS_CANCELLING
:
3553 if (s
->vm_was_running
) {
3556 if (runstate_check(RUN_STATE_FINISH_MIGRATE
)) {
3557 runstate_set(RUN_STATE_POSTMIGRATE
);
3563 /* Should not reach here, but if so, forgive the VM. */
3564 error_report("%s: Unknown ending state %d", __func__
, s
->state
);
3567 migrate_fd_cleanup_schedule(s
);
3568 qemu_mutex_unlock_iothread();
3571 static void bg_migration_iteration_finish(MigrationState
*s
)
3573 qemu_mutex_lock_iothread();
3575 case MIGRATION_STATUS_COMPLETED
:
3576 migration_calculate_complete(s
);
3579 case MIGRATION_STATUS_ACTIVE
:
3580 case MIGRATION_STATUS_FAILED
:
3581 case MIGRATION_STATUS_CANCELLED
:
3582 case MIGRATION_STATUS_CANCELLING
:
3586 /* Should not reach here, but if so, forgive the VM. */
3587 error_report("%s: Unknown ending state %d", __func__
, s
->state
);
3591 migrate_fd_cleanup_schedule(s
);
3592 qemu_mutex_unlock_iothread();
3596 * Return true if continue to the next iteration directly, false
3599 static MigIterateState
bg_migration_iteration_run(MigrationState
*s
)
3603 res
= qemu_savevm_state_iterate(s
->to_dst_file
, false);
3605 bg_migration_completion(s
);
3606 return MIG_ITERATE_BREAK
;
3609 return MIG_ITERATE_RESUME
;
3612 void migration_make_urgent_request(void)
3614 qemu_sem_post(&migrate_get_current()->rate_limit_sem
);
3617 void migration_consume_urgent_request(void)
3619 qemu_sem_wait(&migrate_get_current()->rate_limit_sem
);
3622 /* Returns true if the rate limiting was broken by an urgent request */
3623 bool migration_rate_limit(void)
3625 int64_t now
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3626 MigrationState
*s
= migrate_get_current();
3628 bool urgent
= false;
3629 migration_update_counters(s
, now
);
3630 if (qemu_file_rate_limit(s
->to_dst_file
)) {
3632 if (qemu_file_get_error(s
->to_dst_file
)) {
3636 * Wait for a delay to do rate limiting OR
3637 * something urgent to post the semaphore.
3639 int ms
= s
->iteration_start_time
+ BUFFER_DELAY
- now
;
3640 trace_migration_rate_limit_pre(ms
);
3641 if (qemu_sem_timedwait(&s
->rate_limit_sem
, ms
) == 0) {
3643 * We were woken by one or more urgent things but
3644 * the timedwait will have consumed one of them.
3645 * The service routine for the urgent wake will dec
3646 * the semaphore itself for each item it consumes,
3647 * so add this one we just eat back.
3649 qemu_sem_post(&s
->rate_limit_sem
);
3652 trace_migration_rate_limit_post(urgent
);
3658 * Master migration thread on the source VM.
3659 * It drives the migration and pumps the data down the outgoing channel.
3661 static void *migration_thread(void *opaque
)
3663 MigrationState
*s
= opaque
;
3664 int64_t setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
3665 MigThrError thr_error
;
3666 bool urgent
= false;
3668 rcu_register_thread();
3670 object_ref(OBJECT(s
));
3671 update_iteration_initial_status(s
);
3673 qemu_savevm_state_header(s
->to_dst_file
);
3676 * If we opened the return path, we need to make sure dst has it
3679 if (s
->rp_state
.from_dst_file
) {
3680 /* Now tell the dest that it should open its end so it can reply */
3681 qemu_savevm_send_open_return_path(s
->to_dst_file
);
3683 /* And do a ping that will make stuff easier to debug */
3684 qemu_savevm_send_ping(s
->to_dst_file
, 1);
3687 if (migrate_postcopy()) {
3689 * Tell the destination that we *might* want to do postcopy later;
3690 * if the other end can't do postcopy it should fail now, nice and
3693 qemu_savevm_send_postcopy_advise(s
->to_dst_file
);
3696 if (migrate_colo_enabled()) {
3697 /* Notify migration destination that we enable COLO */
3698 qemu_savevm_send_colo_enable(s
->to_dst_file
);
3701 qemu_savevm_state_setup(s
->to_dst_file
);
3703 if (qemu_savevm_state_guest_unplug_pending()) {
3704 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3705 MIGRATION_STATUS_WAIT_UNPLUG
);
3707 while (s
->state
== MIGRATION_STATUS_WAIT_UNPLUG
&&
3708 qemu_savevm_state_guest_unplug_pending()) {
3709 qemu_sem_timedwait(&s
->wait_unplug_sem
, 250);
3712 migrate_set_state(&s
->state
, MIGRATION_STATUS_WAIT_UNPLUG
,
3713 MIGRATION_STATUS_ACTIVE
);
3716 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
3717 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3718 MIGRATION_STATUS_ACTIVE
);
3720 trace_migration_thread_setup_complete();
3722 while (migration_is_active(s
)) {
3723 if (urgent
|| !qemu_file_rate_limit(s
->to_dst_file
)) {
3724 MigIterateState iter_state
= migration_iteration_run(s
);
3725 if (iter_state
== MIG_ITERATE_SKIP
) {
3727 } else if (iter_state
== MIG_ITERATE_BREAK
) {
3733 * Try to detect any kind of failures, and see whether we
3734 * should stop the migration now.
3736 thr_error
= migration_detect_error(s
);
3737 if (thr_error
== MIG_THR_ERR_FATAL
) {
3738 /* Stop migration */
3740 } else if (thr_error
== MIG_THR_ERR_RECOVERED
) {
3742 * Just recovered from a e.g. network failure, reset all
3743 * the local variables. This is important to avoid
3744 * breaking transferred_bytes and bandwidth calculation
3746 update_iteration_initial_status(s
);
3749 urgent
= migration_rate_limit();
3752 trace_migration_thread_after_loop();
3753 migration_iteration_finish(s
);
3754 object_unref(OBJECT(s
));
3755 rcu_unregister_thread();
3759 static void bg_migration_vm_start_bh(void *opaque
)
3761 MigrationState
*s
= opaque
;
3763 qemu_bh_delete(s
->vm_start_bh
);
3764 s
->vm_start_bh
= NULL
;
3767 s
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - s
->downtime_start
;
3771 * Background snapshot thread, based on live migration code.
3772 * This is an alternative implementation of live migration mechanism
3773 * introduced specifically to support background snapshots.
3775 * It takes advantage of userfault_fd write protection mechanism introduced
3776 * in v5.7 kernel. Compared to existing dirty page logging migration much
3777 * lesser stream traffic is produced resulting in smaller snapshot images,
3778 * simply cause of no page duplicates can get into the stream.
3780 * Another key point is that generated vmstate stream reflects machine state
3781 * 'frozen' at the beginning of snapshot creation compared to dirty page logging
3782 * mechanism, which effectively results in that saved snapshot is the state of VM
3783 * at the end of the process.
3785 static void *bg_migration_thread(void *opaque
)
3787 MigrationState
*s
= opaque
;
3788 int64_t setup_start
;
3789 MigThrError thr_error
;
3791 bool early_fail
= true;
3793 rcu_register_thread();
3794 object_ref(OBJECT(s
));
3796 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
3798 setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
3800 * We want to save vmstate for the moment when migration has been
3801 * initiated but also we want to save RAM content while VM is running.
3802 * The RAM content should appear first in the vmstate. So, we first
3803 * stash the non-RAM part of the vmstate to the temporary buffer,
3804 * then write RAM part of the vmstate to the migration stream
3805 * with vCPUs running and, finally, write stashed non-RAM part of
3806 * the vmstate from the buffer to the migration stream.
3808 s
->bioc
= qio_channel_buffer_new(512 * 1024);
3809 qio_channel_set_name(QIO_CHANNEL(s
->bioc
), "vmstate-buffer");
3810 fb
= qemu_fopen_channel_output(QIO_CHANNEL(s
->bioc
));
3811 object_unref(OBJECT(s
->bioc
));
3813 update_iteration_initial_status(s
);
3816 * Prepare for tracking memory writes with UFFD-WP - populate
3817 * RAM pages before protecting.
3820 ram_write_tracking_prepare();
3823 qemu_savevm_state_header(s
->to_dst_file
);
3824 qemu_savevm_state_setup(s
->to_dst_file
);
3826 if (qemu_savevm_state_guest_unplug_pending()) {
3827 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3828 MIGRATION_STATUS_WAIT_UNPLUG
);
3830 while (s
->state
== MIGRATION_STATUS_WAIT_UNPLUG
&&
3831 qemu_savevm_state_guest_unplug_pending()) {
3832 qemu_sem_timedwait(&s
->wait_unplug_sem
, 250);
3835 migrate_set_state(&s
->state
, MIGRATION_STATUS_WAIT_UNPLUG
,
3836 MIGRATION_STATUS_ACTIVE
);
3838 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3839 MIGRATION_STATUS_ACTIVE
);
3841 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
3843 trace_migration_thread_setup_complete();
3844 s
->downtime_start
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3846 qemu_mutex_lock_iothread();
3849 * If VM is currently in suspended state, then, to make a valid runstate
3850 * transition in vm_stop_force_state() we need to wakeup it up.
3852 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
3853 s
->vm_was_running
= runstate_is_running();
3855 if (global_state_store()) {
3858 /* Forcibly stop VM before saving state of vCPUs and devices */
3859 if (vm_stop_force_state(RUN_STATE_PAUSED
)) {
3863 * Put vCPUs in sync with shadow context structures, then
3864 * save their state to channel-buffer along with devices.
3866 cpu_synchronize_all_states();
3867 if (qemu_savevm_state_complete_precopy_non_iterable(fb
, false, false)) {
3871 * Since we are going to get non-iterable state data directly
3872 * from s->bioc->data, explicit flush is needed here.
3876 /* Now initialize UFFD context and start tracking RAM writes */
3877 if (ram_write_tracking_start()) {
3883 * Start VM from BH handler to avoid write-fault lock here.
3884 * UFFD-WP protection for the whole RAM is already enabled so
3885 * calling VM state change notifiers from vm_start() would initiate
3886 * writes to virtio VQs memory which is in write-protected region.
3888 s
->vm_start_bh
= qemu_bh_new(bg_migration_vm_start_bh
, s
);
3889 qemu_bh_schedule(s
->vm_start_bh
);
3891 qemu_mutex_unlock_iothread();
3893 while (migration_is_active(s
)) {
3894 MigIterateState iter_state
= bg_migration_iteration_run(s
);
3895 if (iter_state
== MIG_ITERATE_SKIP
) {
3897 } else if (iter_state
== MIG_ITERATE_BREAK
) {
3902 * Try to detect any kind of failures, and see whether we
3903 * should stop the migration now.
3905 thr_error
= migration_detect_error(s
);
3906 if (thr_error
== MIG_THR_ERR_FATAL
) {
3907 /* Stop migration */
3911 migration_update_counters(s
, qemu_clock_get_ms(QEMU_CLOCK_REALTIME
));
3914 trace_migration_thread_after_loop();
3918 migrate_set_state(&s
->state
, MIGRATION_STATUS_ACTIVE
,
3919 MIGRATION_STATUS_FAILED
);
3920 qemu_mutex_unlock_iothread();
3923 bg_migration_iteration_finish(s
);
3926 object_unref(OBJECT(s
));
3927 rcu_unregister_thread();
3932 void migrate_fd_connect(MigrationState
*s
, Error
*error_in
)
3934 Error
*local_err
= NULL
;
3936 bool resume
= s
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
;
3938 s
->expected_downtime
= s
->parameters
.downtime_limit
;
3940 assert(s
->cleanup_bh
);
3942 assert(!s
->cleanup_bh
);
3943 s
->cleanup_bh
= qemu_bh_new(migrate_fd_cleanup_bh
, s
);
3946 migrate_fd_error(s
, error_in
);
3947 migrate_fd_cleanup(s
);
3952 /* This is a resumed migration */
3953 rate_limit
= s
->parameters
.max_postcopy_bandwidth
/
3956 /* This is a fresh new migration */
3957 rate_limit
= s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
;
3959 /* Notify before starting migration thread */
3960 notifier_list_notify(&migration_state_notifiers
, s
);
3963 qemu_file_set_rate_limit(s
->to_dst_file
, rate_limit
);
3964 qemu_file_set_blocking(s
->to_dst_file
, true);
3967 * Open the return path. For postcopy, it is used exclusively. For
3968 * precopy, only if user specified "return-path" capability would
3969 * QEMU uses the return path.
3971 if (migrate_postcopy_ram() || migrate_use_return_path()) {
3972 if (open_return_path_on_source(s
, !resume
)) {
3973 error_report("Unable to open return-path for postcopy");
3974 migrate_set_state(&s
->state
, s
->state
, MIGRATION_STATUS_FAILED
);
3975 migrate_fd_cleanup(s
);
3981 /* Wakeup the main migration thread to do the recovery */
3982 migrate_set_state(&s
->state
, MIGRATION_STATUS_POSTCOPY_PAUSED
,
3983 MIGRATION_STATUS_POSTCOPY_RECOVER
);
3984 qemu_sem_post(&s
->postcopy_pause_sem
);
3988 if (multifd_save_setup(&local_err
) != 0) {
3989 error_report_err(local_err
);
3990 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
3991 MIGRATION_STATUS_FAILED
);
3992 migrate_fd_cleanup(s
);
3996 if (migrate_background_snapshot()) {
3997 qemu_thread_create(&s
->thread
, "bg_snapshot",
3998 bg_migration_thread
, s
, QEMU_THREAD_JOINABLE
);
4000 qemu_thread_create(&s
->thread
, "live_migration",
4001 migration_thread
, s
, QEMU_THREAD_JOINABLE
);
4003 s
->migration_thread_running
= true;
4006 void migration_global_dump(Monitor
*mon
)
4008 MigrationState
*ms
= migrate_get_current();
4010 monitor_printf(mon
, "globals:\n");
4011 monitor_printf(mon
, "store-global-state: %s\n",
4012 ms
->store_global_state
? "on" : "off");
4013 monitor_printf(mon
, "only-migratable: %s\n",
4014 only_migratable
? "on" : "off");
4015 monitor_printf(mon
, "send-configuration: %s\n",
4016 ms
->send_configuration
? "on" : "off");
4017 monitor_printf(mon
, "send-section-footer: %s\n",
4018 ms
->send_section_footer
? "on" : "off");
4019 monitor_printf(mon
, "decompress-error-check: %s\n",
4020 ms
->decompress_error_check
? "on" : "off");
4021 monitor_printf(mon
, "clear-bitmap-shift: %u\n",
4022 ms
->clear_bitmap_shift
);
4025 #define DEFINE_PROP_MIG_CAP(name, x) \
4026 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false)
4028 static Property migration_properties
[] = {
4029 DEFINE_PROP_BOOL("store-global-state", MigrationState
,
4030 store_global_state
, true),
4031 DEFINE_PROP_BOOL("send-configuration", MigrationState
,
4032 send_configuration
, true),
4033 DEFINE_PROP_BOOL("send-section-footer", MigrationState
,
4034 send_section_footer
, true),
4035 DEFINE_PROP_BOOL("decompress-error-check", MigrationState
,
4036 decompress_error_check
, true),
4037 DEFINE_PROP_UINT8("x-clear-bitmap-shift", MigrationState
,
4038 clear_bitmap_shift
, CLEAR_BITMAP_SHIFT_DEFAULT
),
4040 /* Migration parameters */
4041 DEFINE_PROP_UINT8("x-compress-level", MigrationState
,
4042 parameters
.compress_level
,
4043 DEFAULT_MIGRATE_COMPRESS_LEVEL
),
4044 DEFINE_PROP_UINT8("x-compress-threads", MigrationState
,
4045 parameters
.compress_threads
,
4046 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT
),
4047 DEFINE_PROP_BOOL("x-compress-wait-thread", MigrationState
,
4048 parameters
.compress_wait_thread
, true),
4049 DEFINE_PROP_UINT8("x-decompress-threads", MigrationState
,
4050 parameters
.decompress_threads
,
4051 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT
),
4052 DEFINE_PROP_UINT8("x-throttle-trigger-threshold", MigrationState
,
4053 parameters
.throttle_trigger_threshold
,
4054 DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD
),
4055 DEFINE_PROP_UINT8("x-cpu-throttle-initial", MigrationState
,
4056 parameters
.cpu_throttle_initial
,
4057 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL
),
4058 DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState
,
4059 parameters
.cpu_throttle_increment
,
4060 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT
),
4061 DEFINE_PROP_BOOL("x-cpu-throttle-tailslow", MigrationState
,
4062 parameters
.cpu_throttle_tailslow
, false),
4063 DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState
,
4064 parameters
.max_bandwidth
, MAX_THROTTLE
),
4065 DEFINE_PROP_UINT64("x-downtime-limit", MigrationState
,
4066 parameters
.downtime_limit
,
4067 DEFAULT_MIGRATE_SET_DOWNTIME
),
4068 DEFINE_PROP_UINT32("x-checkpoint-delay", MigrationState
,
4069 parameters
.x_checkpoint_delay
,
4070 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY
),
4071 DEFINE_PROP_UINT8("multifd-channels", MigrationState
,
4072 parameters
.multifd_channels
,
4073 DEFAULT_MIGRATE_MULTIFD_CHANNELS
),
4074 DEFINE_PROP_MULTIFD_COMPRESSION("multifd-compression", MigrationState
,
4075 parameters
.multifd_compression
,
4076 DEFAULT_MIGRATE_MULTIFD_COMPRESSION
),
4077 DEFINE_PROP_UINT8("multifd-zlib-level", MigrationState
,
4078 parameters
.multifd_zlib_level
,
4079 DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL
),
4080 DEFINE_PROP_UINT8("multifd-zstd-level", MigrationState
,
4081 parameters
.multifd_zstd_level
,
4082 DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL
),
4083 DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState
,
4084 parameters
.xbzrle_cache_size
,
4085 DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE
),
4086 DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState
,
4087 parameters
.max_postcopy_bandwidth
,
4088 DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH
),
4089 DEFINE_PROP_UINT8("max-cpu-throttle", MigrationState
,
4090 parameters
.max_cpu_throttle
,
4091 DEFAULT_MIGRATE_MAX_CPU_THROTTLE
),
4092 DEFINE_PROP_SIZE("announce-initial", MigrationState
,
4093 parameters
.announce_initial
,
4094 DEFAULT_MIGRATE_ANNOUNCE_INITIAL
),
4095 DEFINE_PROP_SIZE("announce-max", MigrationState
,
4096 parameters
.announce_max
,
4097 DEFAULT_MIGRATE_ANNOUNCE_MAX
),
4098 DEFINE_PROP_SIZE("announce-rounds", MigrationState
,
4099 parameters
.announce_rounds
,
4100 DEFAULT_MIGRATE_ANNOUNCE_ROUNDS
),
4101 DEFINE_PROP_SIZE("announce-step", MigrationState
,
4102 parameters
.announce_step
,
4103 DEFAULT_MIGRATE_ANNOUNCE_STEP
),
4105 /* Migration capabilities */
4106 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE
),
4107 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL
),
4108 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE
),
4109 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS
),
4110 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS
),
4111 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS
),
4112 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM
),
4113 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO
),
4114 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM
),
4115 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK
),
4116 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH
),
4117 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_MULTIFD
),
4118 DEFINE_PROP_MIG_CAP("x-background-snapshot",
4119 MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
),
4121 DEFINE_PROP_END_OF_LIST(),
4124 static void migration_class_init(ObjectClass
*klass
, void *data
)
4126 DeviceClass
*dc
= DEVICE_CLASS(klass
);
4128 dc
->user_creatable
= false;
4129 device_class_set_props(dc
, migration_properties
);
4132 static void migration_instance_finalize(Object
*obj
)
4134 MigrationState
*ms
= MIGRATION_OBJ(obj
);
4135 MigrationParameters
*params
= &ms
->parameters
;
4137 qemu_mutex_destroy(&ms
->error_mutex
);
4138 qemu_mutex_destroy(&ms
->qemu_file_lock
);
4139 g_free(params
->tls_hostname
);
4140 g_free(params
->tls_creds
);
4141 qemu_sem_destroy(&ms
->wait_unplug_sem
);
4142 qemu_sem_destroy(&ms
->rate_limit_sem
);
4143 qemu_sem_destroy(&ms
->pause_sem
);
4144 qemu_sem_destroy(&ms
->postcopy_pause_sem
);
4145 qemu_sem_destroy(&ms
->postcopy_pause_rp_sem
);
4146 qemu_sem_destroy(&ms
->rp_state
.rp_sem
);
4147 error_free(ms
->error
);
4150 static void migration_instance_init(Object
*obj
)
4152 MigrationState
*ms
= MIGRATION_OBJ(obj
);
4153 MigrationParameters
*params
= &ms
->parameters
;
4155 ms
->state
= MIGRATION_STATUS_NONE
;
4157 ms
->pages_per_second
= -1;
4158 qemu_sem_init(&ms
->pause_sem
, 0);
4159 qemu_mutex_init(&ms
->error_mutex
);
4161 params
->tls_hostname
= g_strdup("");
4162 params
->tls_creds
= g_strdup("");
4164 /* Set has_* up only for parameter checks */
4165 params
->has_compress_level
= true;
4166 params
->has_compress_threads
= true;
4167 params
->has_decompress_threads
= true;
4168 params
->has_throttle_trigger_threshold
= true;
4169 params
->has_cpu_throttle_initial
= true;
4170 params
->has_cpu_throttle_increment
= true;
4171 params
->has_cpu_throttle_tailslow
= true;
4172 params
->has_max_bandwidth
= true;
4173 params
->has_downtime_limit
= true;
4174 params
->has_x_checkpoint_delay
= true;
4175 params
->has_block_incremental
= true;
4176 params
->has_multifd_channels
= true;
4177 params
->has_multifd_compression
= true;
4178 params
->has_multifd_zlib_level
= true;
4179 params
->has_multifd_zstd_level
= true;
4180 params
->has_xbzrle_cache_size
= true;
4181 params
->has_max_postcopy_bandwidth
= true;
4182 params
->has_max_cpu_throttle
= true;
4183 params
->has_announce_initial
= true;
4184 params
->has_announce_max
= true;
4185 params
->has_announce_rounds
= true;
4186 params
->has_announce_step
= true;
4188 qemu_sem_init(&ms
->postcopy_pause_sem
, 0);
4189 qemu_sem_init(&ms
->postcopy_pause_rp_sem
, 0);
4190 qemu_sem_init(&ms
->rp_state
.rp_sem
, 0);
4191 qemu_sem_init(&ms
->rate_limit_sem
, 0);
4192 qemu_sem_init(&ms
->wait_unplug_sem
, 0);
4193 qemu_mutex_init(&ms
->qemu_file_lock
);
4197 * Return true if check pass, false otherwise. Error will be put
4198 * inside errp if provided.
4200 static bool migration_object_check(MigrationState
*ms
, Error
**errp
)
4202 MigrationCapabilityStatusList
*head
= NULL
;
4203 /* Assuming all off */
4204 bool cap_list
[MIGRATION_CAPABILITY__MAX
] = { 0 }, ret
;
4207 if (!migrate_params_check(&ms
->parameters
, errp
)) {
4211 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
4212 if (ms
->enabled_capabilities
[i
]) {
4213 QAPI_LIST_PREPEND(head
, migrate_cap_add(i
, true));
4217 ret
= migrate_caps_check(cap_list
, head
, errp
);
4219 /* It works with head == NULL */
4220 qapi_free_MigrationCapabilityStatusList(head
);
4225 static const TypeInfo migration_type
= {
4226 .name
= TYPE_MIGRATION
,
4228 * NOTE: TYPE_MIGRATION is not really a device, as the object is
4229 * not created using qdev_new(), it is not attached to the qdev
4230 * device tree, and it is never realized.
4232 * TODO: Make this TYPE_OBJECT once QOM provides something like
4233 * TYPE_DEVICE's "-global" properties.
4235 .parent
= TYPE_DEVICE
,
4236 .class_init
= migration_class_init
,
4237 .class_size
= sizeof(MigrationClass
),
4238 .instance_size
= sizeof(MigrationState
),
4239 .instance_init
= migration_instance_init
,
4240 .instance_finalize
= migration_instance_finalize
,
4243 static void register_migration_types(void)
4245 type_register_static(&migration_type
);
4248 type_init(register_migration_types
);