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"
62 #include "yank_functions.h"
64 #define MAX_THROTTLE (128 << 20) /* Migration transfer speed throttling */
66 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
68 #define BUFFER_DELAY 100
69 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
71 /* Time in milliseconds we are allowed to stop the source,
72 * for sending the last part */
73 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
75 /* Maximum migrate downtime set to 2000 seconds */
76 #define MAX_MIGRATE_DOWNTIME_SECONDS 2000
77 #define MAX_MIGRATE_DOWNTIME (MAX_MIGRATE_DOWNTIME_SECONDS * 1000)
79 /* Default compression thread count */
80 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
81 /* Default decompression thread count, usually decompression is at
82 * least 4 times as fast as compression.*/
83 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
84 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
85 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
86 /* Define default autoconverge cpu throttle migration parameters */
87 #define DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD 50
88 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
89 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
90 #define DEFAULT_MIGRATE_MAX_CPU_THROTTLE 99
92 /* Migration XBZRLE default cache size */
93 #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024)
95 /* The delay time (in ms) between two COLO checkpoints */
96 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100)
97 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
98 #define DEFAULT_MIGRATE_MULTIFD_COMPRESSION MULTIFD_COMPRESSION_NONE
99 /* 0: means nocompress, 1: best speed, ... 9: best compress ratio */
100 #define DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL 1
101 /* 0: means nocompress, 1: best speed, ... 20: best compress ratio */
102 #define DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL 1
104 /* Background transfer rate for postcopy, 0 means unlimited, note
105 * that page requests can still exceed this limit.
107 #define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0
110 * Parameters for self_announce_delay giving a stream of RARP/ARP
111 * packets after migration.
113 #define DEFAULT_MIGRATE_ANNOUNCE_INITIAL 50
114 #define DEFAULT_MIGRATE_ANNOUNCE_MAX 550
115 #define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS 5
116 #define DEFAULT_MIGRATE_ANNOUNCE_STEP 100
118 static NotifierList migration_state_notifiers
=
119 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers
);
121 /* Messages sent on the return path from destination to source */
122 enum mig_rp_message_type
{
123 MIG_RP_MSG_INVALID
= 0, /* Must be 0 */
124 MIG_RP_MSG_SHUT
, /* sibling will not send any more RP messages */
125 MIG_RP_MSG_PONG
, /* Response to a PING; data (seq: be32 ) */
127 MIG_RP_MSG_REQ_PAGES_ID
, /* data (start: be64, len: be32, id: string) */
128 MIG_RP_MSG_REQ_PAGES
, /* data (start: be64, len: be32) */
129 MIG_RP_MSG_RECV_BITMAP
, /* send recved_bitmap back to source */
130 MIG_RP_MSG_RESUME_ACK
, /* tell source that we are ready to resume */
135 /* Migration capabilities set */
136 struct MigrateCapsSet
{
137 int size
; /* Capability set size */
138 MigrationCapability caps
[]; /* Variadic array of capabilities */
140 typedef struct MigrateCapsSet MigrateCapsSet
;
142 /* Define and initialize MigrateCapsSet */
143 #define INITIALIZE_MIGRATE_CAPS_SET(_name, ...) \
144 MigrateCapsSet _name = { \
145 .size = sizeof((int []) { __VA_ARGS__ }) / sizeof(int), \
146 .caps = { __VA_ARGS__ } \
149 /* Background-snapshot compatibility check list */
151 INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot
,
152 MIGRATION_CAPABILITY_POSTCOPY_RAM
,
153 MIGRATION_CAPABILITY_DIRTY_BITMAPS
,
154 MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME
,
155 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE
,
156 MIGRATION_CAPABILITY_RETURN_PATH
,
157 MIGRATION_CAPABILITY_MULTIFD
,
158 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER
,
159 MIGRATION_CAPABILITY_AUTO_CONVERGE
,
160 MIGRATION_CAPABILITY_RELEASE_RAM
,
161 MIGRATION_CAPABILITY_RDMA_PIN_ALL
,
162 MIGRATION_CAPABILITY_COMPRESS
,
163 MIGRATION_CAPABILITY_XBZRLE
,
164 MIGRATION_CAPABILITY_X_COLO
,
165 MIGRATION_CAPABILITY_VALIDATE_UUID
);
167 /* When we add fault tolerance, we could have several
168 migrations at once. For now we don't need to add
169 dynamic creation of migration */
171 static MigrationState
*current_migration
;
172 static MigrationIncomingState
*current_incoming
;
174 static GSList
*migration_blockers
;
176 static bool migration_object_check(MigrationState
*ms
, Error
**errp
);
177 static int migration_maybe_pause(MigrationState
*s
,
178 int *current_active_state
,
180 static void migrate_fd_cancel(MigrationState
*s
);
182 static gint
page_request_addr_cmp(gconstpointer ap
, gconstpointer bp
)
184 uintptr_t a
= (uintptr_t) ap
, b
= (uintptr_t) bp
;
186 return (a
> b
) - (a
< b
);
189 void migration_object_init(void)
191 /* This can only be called once. */
192 assert(!current_migration
);
193 current_migration
= MIGRATION_OBJ(object_new(TYPE_MIGRATION
));
196 * Init the migrate incoming object as well no matter whether
197 * we'll use it or not.
199 assert(!current_incoming
);
200 current_incoming
= g_new0(MigrationIncomingState
, 1);
201 current_incoming
->state
= MIGRATION_STATUS_NONE
;
202 current_incoming
->postcopy_remote_fds
=
203 g_array_new(FALSE
, TRUE
, sizeof(struct PostCopyFD
));
204 qemu_mutex_init(¤t_incoming
->rp_mutex
);
205 qemu_event_init(¤t_incoming
->main_thread_load_event
, false);
206 qemu_sem_init(¤t_incoming
->postcopy_pause_sem_dst
, 0);
207 qemu_sem_init(¤t_incoming
->postcopy_pause_sem_fault
, 0);
208 qemu_mutex_init(¤t_incoming
->page_request_mutex
);
209 current_incoming
->page_requested
= g_tree_new(page_request_addr_cmp
);
211 migration_object_check(current_migration
, &error_fatal
);
215 dirty_bitmap_mig_init();
218 void migration_cancel(const Error
*error
)
221 migrate_set_error(current_migration
, error
);
223 migrate_fd_cancel(current_migration
);
226 void migration_shutdown(void)
229 * When the QEMU main thread exit, the COLO thread
230 * may wait a semaphore. So, we should wakeup the
231 * COLO thread before migration shutdown.
235 * Cancel the current migration - that will (eventually)
236 * stop the migration using this structure
238 migration_cancel(NULL
);
239 object_unref(OBJECT(current_migration
));
242 * Cancel outgoing migration of dirty bitmaps. It should
243 * at least unref used block nodes.
245 dirty_bitmap_mig_cancel_outgoing();
248 * Cancel incoming migration of dirty bitmaps. Dirty bitmaps
249 * are non-critical data, and their loss never considered as
252 dirty_bitmap_mig_cancel_incoming();
256 MigrationState
*migrate_get_current(void)
258 /* This can only be called after the object created. */
259 assert(current_migration
);
260 return current_migration
;
263 MigrationIncomingState
*migration_incoming_get_current(void)
265 assert(current_incoming
);
266 return current_incoming
;
269 void migration_incoming_state_destroy(void)
271 struct MigrationIncomingState
*mis
= migration_incoming_get_current();
273 if (mis
->to_src_file
) {
274 /* Tell source that we are done */
275 migrate_send_rp_shut(mis
, qemu_file_get_error(mis
->from_src_file
) != 0);
276 qemu_fclose(mis
->to_src_file
);
277 mis
->to_src_file
= NULL
;
280 if (mis
->from_src_file
) {
281 migration_ioc_unregister_yank_from_file(mis
->from_src_file
);
282 qemu_fclose(mis
->from_src_file
);
283 mis
->from_src_file
= NULL
;
285 if (mis
->postcopy_remote_fds
) {
286 g_array_free(mis
->postcopy_remote_fds
, TRUE
);
287 mis
->postcopy_remote_fds
= NULL
;
289 if (mis
->transport_cleanup
) {
290 mis
->transport_cleanup(mis
->transport_data
);
293 qemu_event_reset(&mis
->main_thread_load_event
);
295 if (mis
->page_requested
) {
296 g_tree_destroy(mis
->page_requested
);
297 mis
->page_requested
= NULL
;
300 if (mis
->socket_address_list
) {
301 qapi_free_SocketAddressList(mis
->socket_address_list
);
302 mis
->socket_address_list
= NULL
;
305 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
308 static void migrate_generate_event(int new_state
)
310 if (migrate_use_events()) {
311 qapi_event_send_migration(new_state
);
315 static bool migrate_late_block_activate(void)
319 s
= migrate_get_current();
321 return s
->enabled_capabilities
[
322 MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE
];
326 * Send a message on the return channel back to the source
329 static int migrate_send_rp_message(MigrationIncomingState
*mis
,
330 enum mig_rp_message_type message_type
,
331 uint16_t len
, void *data
)
335 trace_migrate_send_rp_message((int)message_type
, len
);
336 QEMU_LOCK_GUARD(&mis
->rp_mutex
);
339 * It's possible that the file handle got lost due to network
342 if (!mis
->to_src_file
) {
347 qemu_put_be16(mis
->to_src_file
, (unsigned int)message_type
);
348 qemu_put_be16(mis
->to_src_file
, len
);
349 qemu_put_buffer(mis
->to_src_file
, data
, len
);
350 qemu_fflush(mis
->to_src_file
);
352 /* It's possible that qemu file got error during sending */
353 ret
= qemu_file_get_error(mis
->to_src_file
);
358 /* Request one page from the source VM at the given start address.
359 * rb: the RAMBlock to request the page in
360 * Start: Address offset within the RB
361 * Len: Length in bytes required - must be a multiple of pagesize
363 int migrate_send_rp_message_req_pages(MigrationIncomingState
*mis
,
364 RAMBlock
*rb
, ram_addr_t start
)
366 uint8_t bufc
[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
367 size_t msglen
= 12; /* start + len */
368 size_t len
= qemu_ram_pagesize(rb
);
369 enum mig_rp_message_type msg_type
;
373 *(uint64_t *)bufc
= cpu_to_be64((uint64_t)start
);
374 *(uint32_t *)(bufc
+ 8) = cpu_to_be32((uint32_t)len
);
377 * We maintain the last ramblock that we requested for page. Note that we
378 * don't need locking because this function will only be called within the
379 * postcopy ram fault thread.
381 if (rb
!= mis
->last_rb
) {
384 rbname
= qemu_ram_get_idstr(rb
);
385 rbname_len
= strlen(rbname
);
387 assert(rbname_len
< 256);
389 bufc
[msglen
++] = rbname_len
;
390 memcpy(bufc
+ msglen
, rbname
, rbname_len
);
391 msglen
+= rbname_len
;
392 msg_type
= MIG_RP_MSG_REQ_PAGES_ID
;
394 msg_type
= MIG_RP_MSG_REQ_PAGES
;
397 return migrate_send_rp_message(mis
, msg_type
, msglen
, bufc
);
400 int migrate_send_rp_req_pages(MigrationIncomingState
*mis
,
401 RAMBlock
*rb
, ram_addr_t start
, uint64_t haddr
)
403 void *aligned
= (void *)(uintptr_t)ROUND_DOWN(haddr
, qemu_ram_pagesize(rb
));
404 bool received
= false;
406 WITH_QEMU_LOCK_GUARD(&mis
->page_request_mutex
) {
407 received
= ramblock_recv_bitmap_test_byte_offset(rb
, start
);
408 if (!received
&& !g_tree_lookup(mis
->page_requested
, aligned
)) {
410 * The page has not been received, and it's not yet in the page
411 * request list. Queue it. Set the value of element to 1, so that
412 * things like g_tree_lookup() will return TRUE (1) when found.
414 g_tree_insert(mis
->page_requested
, aligned
, (gpointer
)1);
415 mis
->page_requested_count
++;
416 trace_postcopy_page_req_add(aligned
, mis
->page_requested_count
);
421 * If the page is there, skip sending the message. We don't even need the
422 * lock because as long as the page arrived, it'll be there forever.
428 return migrate_send_rp_message_req_pages(mis
, rb
, start
);
431 static bool migration_colo_enabled
;
432 bool migration_incoming_colo_enabled(void)
434 return migration_colo_enabled
;
437 void migration_incoming_disable_colo(void)
439 ram_block_discard_disable(false);
440 migration_colo_enabled
= false;
443 int migration_incoming_enable_colo(void)
445 if (ram_block_discard_disable(true)) {
446 error_report("COLO: cannot disable RAM discard");
449 migration_colo_enabled
= true;
453 void migrate_add_address(SocketAddress
*address
)
455 MigrationIncomingState
*mis
= migration_incoming_get_current();
457 QAPI_LIST_PREPEND(mis
->socket_address_list
,
458 QAPI_CLONE(SocketAddress
, address
));
461 static void qemu_start_incoming_migration(const char *uri
, Error
**errp
)
463 const char *p
= NULL
;
465 migrate_protocol_allow_multifd(false); /* reset it anyway */
466 qapi_event_send_migration(MIGRATION_STATUS_SETUP
);
467 if (strstart(uri
, "tcp:", &p
) ||
468 strstart(uri
, "unix:", NULL
) ||
469 strstart(uri
, "vsock:", NULL
)) {
470 migrate_protocol_allow_multifd(true);
471 socket_start_incoming_migration(p
? p
: uri
, errp
);
473 } else if (strstart(uri
, "rdma:", &p
)) {
474 rdma_start_incoming_migration(p
, errp
);
476 } else if (strstart(uri
, "exec:", &p
)) {
477 exec_start_incoming_migration(p
, errp
);
478 } else if (strstart(uri
, "fd:", &p
)) {
479 fd_start_incoming_migration(p
, errp
);
481 error_setg(errp
, "unknown migration protocol: %s", uri
);
485 static void process_incoming_migration_bh(void *opaque
)
487 Error
*local_err
= NULL
;
488 MigrationIncomingState
*mis
= opaque
;
490 /* If capability late_block_activate is set:
491 * Only fire up the block code now if we're going to restart the
492 * VM, else 'cont' will do it.
493 * This causes file locking to happen; so we don't want it to happen
494 * unless we really are starting the VM.
496 if (!migrate_late_block_activate() ||
497 (autostart
&& (!global_state_received() ||
498 global_state_get_runstate() == RUN_STATE_RUNNING
))) {
499 /* Make sure all file formats flush their mutable metadata.
500 * If we get an error here, just don't restart the VM yet. */
501 bdrv_invalidate_cache_all(&local_err
);
503 error_report_err(local_err
);
510 * This must happen after all error conditions are dealt with and
511 * we're sure the VM is going to be running on this host.
513 qemu_announce_self(&mis
->announce_timer
, migrate_announce_params());
515 if (multifd_load_cleanup(&local_err
) != 0) {
516 error_report_err(local_err
);
519 /* If global state section was not received or we are in running
520 state, we need to obey autostart. Any other state is set with
523 dirty_bitmap_mig_before_vm_start();
525 if (!global_state_received() ||
526 global_state_get_runstate() == RUN_STATE_RUNNING
) {
530 runstate_set(RUN_STATE_PAUSED
);
532 } else if (migration_incoming_colo_enabled()) {
533 migration_incoming_disable_colo();
536 runstate_set(global_state_get_runstate());
539 * This must happen after any state changes since as soon as an external
540 * observer sees this event they might start to prod at the VM assuming
543 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
544 MIGRATION_STATUS_COMPLETED
);
545 qemu_bh_delete(mis
->bh
);
546 migration_incoming_state_destroy();
549 static void process_incoming_migration_co(void *opaque
)
551 MigrationIncomingState
*mis
= migration_incoming_get_current();
554 Error
*local_err
= NULL
;
556 assert(mis
->from_src_file
);
557 mis
->migration_incoming_co
= qemu_coroutine_self();
558 mis
->largest_page_size
= qemu_ram_pagesize_largest();
559 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
560 migrate_set_state(&mis
->state
, MIGRATION_STATUS_NONE
,
561 MIGRATION_STATUS_ACTIVE
);
562 ret
= qemu_loadvm_state(mis
->from_src_file
);
564 ps
= postcopy_state_get();
565 trace_process_incoming_migration_co_end(ret
, ps
);
566 if (ps
!= POSTCOPY_INCOMING_NONE
) {
567 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
569 * Where a migration had postcopy enabled (and thus went to advise)
570 * but managed to complete within the precopy period, we can use
573 postcopy_ram_incoming_cleanup(mis
);
574 } else if (ret
>= 0) {
576 * Postcopy was started, cleanup should happen at the end of the
579 trace_process_incoming_migration_co_postcopy_end_main();
582 /* Else if something went wrong then just fall out of the normal exit */
585 /* we get COLO info, and know if we are in COLO mode */
586 if (!ret
&& migration_incoming_colo_enabled()) {
587 /* Make sure all file formats flush their mutable metadata */
588 bdrv_invalidate_cache_all(&local_err
);
590 error_report_err(local_err
);
594 qemu_thread_create(&mis
->colo_incoming_thread
, "COLO incoming",
595 colo_process_incoming_thread
, mis
, QEMU_THREAD_JOINABLE
);
596 mis
->have_colo_incoming_thread
= true;
597 qemu_coroutine_yield();
599 qemu_mutex_unlock_iothread();
600 /* Wait checkpoint incoming thread exit before free resource */
601 qemu_thread_join(&mis
->colo_incoming_thread
);
602 qemu_mutex_lock_iothread();
603 /* We hold the global iothread lock, so it is safe here */
604 colo_release_ram_cache();
608 error_report("load of migration failed: %s", strerror(-ret
));
611 mis
->bh
= qemu_bh_new(process_incoming_migration_bh
, mis
);
612 qemu_bh_schedule(mis
->bh
);
613 mis
->migration_incoming_co
= NULL
;
617 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
618 MIGRATION_STATUS_FAILED
);
619 qemu_fclose(mis
->from_src_file
);
620 if (multifd_load_cleanup(&local_err
) != 0) {
621 error_report_err(local_err
);
627 * migration_incoming_setup: Setup incoming migration
628 * @f: file for main migration channel
629 * @errp: where to put errors
631 * Returns: %true on success, %false on error.
633 static bool migration_incoming_setup(QEMUFile
*f
, Error
**errp
)
635 MigrationIncomingState
*mis
= migration_incoming_get_current();
637 if (multifd_load_setup(errp
) != 0) {
641 if (!mis
->from_src_file
) {
642 mis
->from_src_file
= f
;
644 qemu_file_set_blocking(f
, false);
648 void migration_incoming_process(void)
650 Coroutine
*co
= qemu_coroutine_create(process_incoming_migration_co
, NULL
);
651 qemu_coroutine_enter(co
);
654 /* Returns true if recovered from a paused migration, otherwise false */
655 static bool postcopy_try_recover(QEMUFile
*f
)
657 MigrationIncomingState
*mis
= migration_incoming_get_current();
659 if (mis
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
660 /* Resumed from a paused postcopy migration */
662 mis
->from_src_file
= f
;
663 /* Postcopy has standalone thread to do vm load */
664 qemu_file_set_blocking(f
, true);
666 /* Re-configure the return path */
667 mis
->to_src_file
= qemu_file_get_return_path(f
);
669 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_PAUSED
,
670 MIGRATION_STATUS_POSTCOPY_RECOVER
);
673 * Here, we only wake up the main loading thread (while the
674 * fault thread will still be waiting), so that we can receive
675 * commands from source now, and answer it if needed. The
676 * fault thread will be woken up afterwards until we are sure
677 * that source is ready to reply to page requests.
679 qemu_sem_post(&mis
->postcopy_pause_sem_dst
);
686 void migration_fd_process_incoming(QEMUFile
*f
, Error
**errp
)
688 if (postcopy_try_recover(f
)) {
692 if (!migration_incoming_setup(f
, errp
)) {
695 migration_incoming_process();
698 void migration_ioc_process_incoming(QIOChannel
*ioc
, Error
**errp
)
700 MigrationIncomingState
*mis
= migration_incoming_get_current();
701 Error
*local_err
= NULL
;
702 bool start_migration
;
704 if (!mis
->from_src_file
) {
705 /* The first connection (multifd may have multiple) */
706 QEMUFile
*f
= qemu_fopen_channel_input(ioc
);
708 /* If it's a recovery, we're done */
709 if (postcopy_try_recover(f
)) {
713 if (!migration_incoming_setup(f
, errp
)) {
718 * Common migration only needs one channel, so we can start
719 * right now. Multifd needs more than one channel, we wait.
721 start_migration
= !migrate_use_multifd();
723 /* Multiple connections */
724 assert(migrate_use_multifd());
725 start_migration
= multifd_recv_new_channel(ioc
, &local_err
);
727 error_propagate(errp
, local_err
);
732 if (start_migration
) {
733 migration_incoming_process();
738 * @migration_has_all_channels: We have received all channels that we need
740 * Returns true when we have got connections to all the channels that
741 * we need for migration.
743 bool migration_has_all_channels(void)
745 MigrationIncomingState
*mis
= migration_incoming_get_current();
748 all_channels
= multifd_recv_all_channels_created();
750 return all_channels
&& mis
->from_src_file
!= NULL
;
754 * Send a 'SHUT' message on the return channel with the given value
755 * to indicate that we've finished with the RP. Non-0 value indicates
758 void migrate_send_rp_shut(MigrationIncomingState
*mis
,
763 buf
= cpu_to_be32(value
);
764 migrate_send_rp_message(mis
, MIG_RP_MSG_SHUT
, sizeof(buf
), &buf
);
768 * Send a 'PONG' message on the return channel with the given value
769 * (normally in response to a 'PING')
771 void migrate_send_rp_pong(MigrationIncomingState
*mis
,
776 buf
= cpu_to_be32(value
);
777 migrate_send_rp_message(mis
, MIG_RP_MSG_PONG
, sizeof(buf
), &buf
);
780 void migrate_send_rp_recv_bitmap(MigrationIncomingState
*mis
,
788 * First, we send the header part. It contains only the len of
789 * idstr, and the idstr itself.
791 len
= strlen(block_name
);
793 memcpy(buf
+ 1, block_name
, len
);
795 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_RECOVER
) {
796 error_report("%s: MSG_RP_RECV_BITMAP only used for recovery",
801 migrate_send_rp_message(mis
, MIG_RP_MSG_RECV_BITMAP
, len
+ 1, buf
);
804 * Next, we dump the received bitmap to the stream.
806 * TODO: currently we are safe since we are the only one that is
807 * using the to_src_file handle (fault thread is still paused),
808 * and it's ok even not taking the mutex. However the best way is
809 * to take the lock before sending the message header, and release
810 * the lock after sending the bitmap.
812 qemu_mutex_lock(&mis
->rp_mutex
);
813 res
= ramblock_recv_bitmap_send(mis
->to_src_file
, block_name
);
814 qemu_mutex_unlock(&mis
->rp_mutex
);
816 trace_migrate_send_rp_recv_bitmap(block_name
, res
);
819 void migrate_send_rp_resume_ack(MigrationIncomingState
*mis
, uint32_t value
)
823 buf
= cpu_to_be32(value
);
824 migrate_send_rp_message(mis
, MIG_RP_MSG_RESUME_ACK
, sizeof(buf
), &buf
);
827 MigrationCapabilityStatusList
*qmp_query_migrate_capabilities(Error
**errp
)
829 MigrationCapabilityStatusList
*head
= NULL
, **tail
= &head
;
830 MigrationCapabilityStatus
*caps
;
831 MigrationState
*s
= migrate_get_current();
834 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
835 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
836 if (i
== MIGRATION_CAPABILITY_BLOCK
) {
840 caps
= g_malloc0(sizeof(*caps
));
841 caps
->capability
= i
;
842 caps
->state
= s
->enabled_capabilities
[i
];
843 QAPI_LIST_APPEND(tail
, caps
);
849 MigrationParameters
*qmp_query_migrate_parameters(Error
**errp
)
851 MigrationParameters
*params
;
852 MigrationState
*s
= migrate_get_current();
854 /* TODO use QAPI_CLONE() instead of duplicating it inline */
855 params
= g_malloc0(sizeof(*params
));
856 params
->has_compress_level
= true;
857 params
->compress_level
= s
->parameters
.compress_level
;
858 params
->has_compress_threads
= true;
859 params
->compress_threads
= s
->parameters
.compress_threads
;
860 params
->has_compress_wait_thread
= true;
861 params
->compress_wait_thread
= s
->parameters
.compress_wait_thread
;
862 params
->has_decompress_threads
= true;
863 params
->decompress_threads
= s
->parameters
.decompress_threads
;
864 params
->has_throttle_trigger_threshold
= true;
865 params
->throttle_trigger_threshold
= s
->parameters
.throttle_trigger_threshold
;
866 params
->has_cpu_throttle_initial
= true;
867 params
->cpu_throttle_initial
= s
->parameters
.cpu_throttle_initial
;
868 params
->has_cpu_throttle_increment
= true;
869 params
->cpu_throttle_increment
= s
->parameters
.cpu_throttle_increment
;
870 params
->has_cpu_throttle_tailslow
= true;
871 params
->cpu_throttle_tailslow
= s
->parameters
.cpu_throttle_tailslow
;
872 params
->has_tls_creds
= true;
873 params
->tls_creds
= g_strdup(s
->parameters
.tls_creds
);
874 params
->has_tls_hostname
= true;
875 params
->tls_hostname
= g_strdup(s
->parameters
.tls_hostname
);
876 params
->has_tls_authz
= true;
877 params
->tls_authz
= g_strdup(s
->parameters
.tls_authz
?
878 s
->parameters
.tls_authz
: "");
879 params
->has_max_bandwidth
= true;
880 params
->max_bandwidth
= s
->parameters
.max_bandwidth
;
881 params
->has_downtime_limit
= true;
882 params
->downtime_limit
= s
->parameters
.downtime_limit
;
883 params
->has_x_checkpoint_delay
= true;
884 params
->x_checkpoint_delay
= s
->parameters
.x_checkpoint_delay
;
885 params
->has_block_incremental
= true;
886 params
->block_incremental
= s
->parameters
.block_incremental
;
887 params
->has_multifd_channels
= true;
888 params
->multifd_channels
= s
->parameters
.multifd_channels
;
889 params
->has_multifd_compression
= true;
890 params
->multifd_compression
= s
->parameters
.multifd_compression
;
891 params
->has_multifd_zlib_level
= true;
892 params
->multifd_zlib_level
= s
->parameters
.multifd_zlib_level
;
893 params
->has_multifd_zstd_level
= true;
894 params
->multifd_zstd_level
= s
->parameters
.multifd_zstd_level
;
895 params
->has_xbzrle_cache_size
= true;
896 params
->xbzrle_cache_size
= s
->parameters
.xbzrle_cache_size
;
897 params
->has_max_postcopy_bandwidth
= true;
898 params
->max_postcopy_bandwidth
= s
->parameters
.max_postcopy_bandwidth
;
899 params
->has_max_cpu_throttle
= true;
900 params
->max_cpu_throttle
= s
->parameters
.max_cpu_throttle
;
901 params
->has_announce_initial
= true;
902 params
->announce_initial
= s
->parameters
.announce_initial
;
903 params
->has_announce_max
= true;
904 params
->announce_max
= s
->parameters
.announce_max
;
905 params
->has_announce_rounds
= true;
906 params
->announce_rounds
= s
->parameters
.announce_rounds
;
907 params
->has_announce_step
= true;
908 params
->announce_step
= s
->parameters
.announce_step
;
910 if (s
->parameters
.has_block_bitmap_mapping
) {
911 params
->has_block_bitmap_mapping
= true;
912 params
->block_bitmap_mapping
=
913 QAPI_CLONE(BitmapMigrationNodeAliasList
,
914 s
->parameters
.block_bitmap_mapping
);
920 AnnounceParameters
*migrate_announce_params(void)
922 static AnnounceParameters ap
;
924 MigrationState
*s
= migrate_get_current();
926 ap
.initial
= s
->parameters
.announce_initial
;
927 ap
.max
= s
->parameters
.announce_max
;
928 ap
.rounds
= s
->parameters
.announce_rounds
;
929 ap
.step
= s
->parameters
.announce_step
;
935 * Return true if we're already in the middle of a migration
936 * (i.e. any of the active or setup states)
938 bool migration_is_setup_or_active(int state
)
941 case MIGRATION_STATUS_ACTIVE
:
942 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
943 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
944 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
945 case MIGRATION_STATUS_SETUP
:
946 case MIGRATION_STATUS_PRE_SWITCHOVER
:
947 case MIGRATION_STATUS_DEVICE
:
948 case MIGRATION_STATUS_WAIT_UNPLUG
:
949 case MIGRATION_STATUS_COLO
:
958 bool migration_is_running(int state
)
961 case MIGRATION_STATUS_ACTIVE
:
962 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
963 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
964 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
965 case MIGRATION_STATUS_SETUP
:
966 case MIGRATION_STATUS_PRE_SWITCHOVER
:
967 case MIGRATION_STATUS_DEVICE
:
968 case MIGRATION_STATUS_WAIT_UNPLUG
:
969 case MIGRATION_STATUS_CANCELLING
:
978 static void populate_time_info(MigrationInfo
*info
, MigrationState
*s
)
980 info
->has_status
= true;
981 info
->has_setup_time
= true;
982 info
->setup_time
= s
->setup_time
;
983 if (s
->state
== MIGRATION_STATUS_COMPLETED
) {
984 info
->has_total_time
= true;
985 info
->total_time
= s
->total_time
;
986 info
->has_downtime
= true;
987 info
->downtime
= s
->downtime
;
989 info
->has_total_time
= true;
990 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) -
992 info
->has_expected_downtime
= true;
993 info
->expected_downtime
= s
->expected_downtime
;
997 static void populate_ram_info(MigrationInfo
*info
, MigrationState
*s
)
999 size_t page_size
= qemu_target_page_size();
1001 info
->has_ram
= true;
1002 info
->ram
= g_malloc0(sizeof(*info
->ram
));
1003 info
->ram
->transferred
= ram_counters
.transferred
;
1004 info
->ram
->total
= ram_bytes_total();
1005 info
->ram
->duplicate
= ram_counters
.duplicate
;
1006 /* legacy value. It is not used anymore */
1007 info
->ram
->skipped
= 0;
1008 info
->ram
->normal
= ram_counters
.normal
;
1009 info
->ram
->normal_bytes
= ram_counters
.normal
* page_size
;
1010 info
->ram
->mbps
= s
->mbps
;
1011 info
->ram
->dirty_sync_count
= ram_counters
.dirty_sync_count
;
1012 info
->ram
->postcopy_requests
= ram_counters
.postcopy_requests
;
1013 info
->ram
->page_size
= page_size
;
1014 info
->ram
->multifd_bytes
= ram_counters
.multifd_bytes
;
1015 info
->ram
->pages_per_second
= s
->pages_per_second
;
1017 if (migrate_use_xbzrle()) {
1018 info
->has_xbzrle_cache
= true;
1019 info
->xbzrle_cache
= g_malloc0(sizeof(*info
->xbzrle_cache
));
1020 info
->xbzrle_cache
->cache_size
= migrate_xbzrle_cache_size();
1021 info
->xbzrle_cache
->bytes
= xbzrle_counters
.bytes
;
1022 info
->xbzrle_cache
->pages
= xbzrle_counters
.pages
;
1023 info
->xbzrle_cache
->cache_miss
= xbzrle_counters
.cache_miss
;
1024 info
->xbzrle_cache
->cache_miss_rate
= xbzrle_counters
.cache_miss_rate
;
1025 info
->xbzrle_cache
->encoding_rate
= xbzrle_counters
.encoding_rate
;
1026 info
->xbzrle_cache
->overflow
= xbzrle_counters
.overflow
;
1029 if (migrate_use_compression()) {
1030 info
->has_compression
= true;
1031 info
->compression
= g_malloc0(sizeof(*info
->compression
));
1032 info
->compression
->pages
= compression_counters
.pages
;
1033 info
->compression
->busy
= compression_counters
.busy
;
1034 info
->compression
->busy_rate
= compression_counters
.busy_rate
;
1035 info
->compression
->compressed_size
=
1036 compression_counters
.compressed_size
;
1037 info
->compression
->compression_rate
=
1038 compression_counters
.compression_rate
;
1041 if (cpu_throttle_active()) {
1042 info
->has_cpu_throttle_percentage
= true;
1043 info
->cpu_throttle_percentage
= cpu_throttle_get_percentage();
1046 if (s
->state
!= MIGRATION_STATUS_COMPLETED
) {
1047 info
->ram
->remaining
= ram_bytes_remaining();
1048 info
->ram
->dirty_pages_rate
= ram_counters
.dirty_pages_rate
;
1052 static void populate_disk_info(MigrationInfo
*info
)
1054 if (blk_mig_active()) {
1055 info
->has_disk
= true;
1056 info
->disk
= g_malloc0(sizeof(*info
->disk
));
1057 info
->disk
->transferred
= blk_mig_bytes_transferred();
1058 info
->disk
->remaining
= blk_mig_bytes_remaining();
1059 info
->disk
->total
= blk_mig_bytes_total();
1063 static void fill_source_migration_info(MigrationInfo
*info
)
1065 MigrationState
*s
= migrate_get_current();
1066 GSList
*cur_blocker
= migration_blockers
;
1068 info
->blocked_reasons
= NULL
;
1071 * There are two types of reasons a migration might be blocked;
1072 * a) devices marked in VMState as non-migratable, and
1073 * b) Explicit migration blockers
1074 * We need to add both of them here.
1076 qemu_savevm_non_migratable_list(&info
->blocked_reasons
);
1078 while (cur_blocker
) {
1079 QAPI_LIST_PREPEND(info
->blocked_reasons
,
1080 g_strdup(error_get_pretty(cur_blocker
->data
)));
1081 cur_blocker
= g_slist_next(cur_blocker
);
1083 info
->has_blocked_reasons
= info
->blocked_reasons
!= NULL
;
1086 case MIGRATION_STATUS_NONE
:
1087 /* no migration has happened ever */
1088 /* do not overwrite destination migration status */
1090 case MIGRATION_STATUS_SETUP
:
1091 info
->has_status
= true;
1092 info
->has_total_time
= false;
1094 case MIGRATION_STATUS_ACTIVE
:
1095 case MIGRATION_STATUS_CANCELLING
:
1096 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1097 case MIGRATION_STATUS_PRE_SWITCHOVER
:
1098 case MIGRATION_STATUS_DEVICE
:
1099 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1100 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1101 /* TODO add some postcopy stats */
1102 populate_time_info(info
, s
);
1103 populate_ram_info(info
, s
);
1104 populate_disk_info(info
);
1105 populate_vfio_info(info
);
1107 case MIGRATION_STATUS_COLO
:
1108 info
->has_status
= true;
1109 /* TODO: display COLO specific information (checkpoint info etc.) */
1111 case MIGRATION_STATUS_COMPLETED
:
1112 populate_time_info(info
, s
);
1113 populate_ram_info(info
, s
);
1114 populate_vfio_info(info
);
1116 case MIGRATION_STATUS_FAILED
:
1117 info
->has_status
= true;
1119 info
->has_error_desc
= true;
1120 info
->error_desc
= g_strdup(error_get_pretty(s
->error
));
1123 case MIGRATION_STATUS_CANCELLED
:
1124 info
->has_status
= true;
1126 case MIGRATION_STATUS_WAIT_UNPLUG
:
1127 info
->has_status
= true;
1130 info
->status
= s
->state
;
1133 typedef enum WriteTrackingSupport
{
1134 WT_SUPPORT_UNKNOWN
= 0,
1136 WT_SUPPORT_AVAILABLE
,
1137 WT_SUPPORT_COMPATIBLE
1138 } WriteTrackingSupport
;
1141 WriteTrackingSupport
migrate_query_write_tracking(void)
1143 /* Check if kernel supports required UFFD features */
1144 if (!ram_write_tracking_available()) {
1145 return WT_SUPPORT_ABSENT
;
1148 * Check if current memory configuration is
1149 * compatible with required UFFD features.
1151 if (!ram_write_tracking_compatible()) {
1152 return WT_SUPPORT_AVAILABLE
;
1155 return WT_SUPPORT_COMPATIBLE
;
1159 * @migration_caps_check - check capability validity
1161 * @cap_list: old capability list, array of bool
1162 * @params: new capabilities to be applied soon
1163 * @errp: set *errp if the check failed, with reason
1165 * Returns true if check passed, otherwise false.
1167 static bool migrate_caps_check(bool *cap_list
,
1168 MigrationCapabilityStatusList
*params
,
1171 MigrationCapabilityStatusList
*cap
;
1172 bool old_postcopy_cap
;
1173 MigrationIncomingState
*mis
= migration_incoming_get_current();
1175 old_postcopy_cap
= cap_list
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
1177 for (cap
= params
; cap
; cap
= cap
->next
) {
1178 cap_list
[cap
->value
->capability
] = cap
->value
->state
;
1181 #ifndef CONFIG_LIVE_BLOCK_MIGRATION
1182 if (cap_list
[MIGRATION_CAPABILITY_BLOCK
]) {
1183 error_setg(errp
, "QEMU compiled without old-style (blk/-b, inc/-i) "
1185 error_append_hint(errp
, "Use drive_mirror+NBD instead.\n");
1190 #ifndef CONFIG_REPLICATION
1191 if (cap_list
[MIGRATION_CAPABILITY_X_COLO
]) {
1192 error_setg(errp
, "QEMU compiled without replication module"
1193 " can't enable COLO");
1194 error_append_hint(errp
, "Please enable replication before COLO.\n");
1199 if (cap_list
[MIGRATION_CAPABILITY_POSTCOPY_RAM
]) {
1200 /* This check is reasonably expensive, so only when it's being
1201 * set the first time, also it's only the destination that needs
1204 if (!old_postcopy_cap
&& runstate_check(RUN_STATE_INMIGRATE
) &&
1205 !postcopy_ram_supported_by_host(mis
)) {
1206 /* postcopy_ram_supported_by_host will have emitted a more
1209 error_setg(errp
, "Postcopy is not supported");
1213 if (cap_list
[MIGRATION_CAPABILITY_X_IGNORE_SHARED
]) {
1214 error_setg(errp
, "Postcopy is not compatible with ignore-shared");
1219 if (cap_list
[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
]) {
1220 WriteTrackingSupport wt_support
;
1223 * Check if 'background-snapshot' capability is supported by
1224 * host kernel and compatible with guest memory configuration.
1226 wt_support
= migrate_query_write_tracking();
1227 if (wt_support
< WT_SUPPORT_AVAILABLE
) {
1228 error_setg(errp
, "Background-snapshot is not supported by host kernel");
1231 if (wt_support
< WT_SUPPORT_COMPATIBLE
) {
1232 error_setg(errp
, "Background-snapshot is not compatible "
1233 "with guest memory configuration");
1238 * Check if there are any migration capabilities
1239 * incompatible with 'background-snapshot'.
1241 for (idx
= 0; idx
< check_caps_background_snapshot
.size
; idx
++) {
1242 int incomp_cap
= check_caps_background_snapshot
.caps
[idx
];
1243 if (cap_list
[incomp_cap
]) {
1245 "Background-snapshot is not compatible with %s",
1246 MigrationCapability_str(incomp_cap
));
1252 /* incoming side only */
1253 if (runstate_check(RUN_STATE_INMIGRATE
) &&
1254 !migrate_multifd_is_allowed() &&
1255 cap_list
[MIGRATION_CAPABILITY_MULTIFD
]) {
1256 error_setg(errp
, "multifd is not supported by current protocol");
1263 static void fill_destination_migration_info(MigrationInfo
*info
)
1265 MigrationIncomingState
*mis
= migration_incoming_get_current();
1267 if (mis
->socket_address_list
) {
1268 info
->has_socket_address
= true;
1269 info
->socket_address
=
1270 QAPI_CLONE(SocketAddressList
, mis
->socket_address_list
);
1273 switch (mis
->state
) {
1274 case MIGRATION_STATUS_NONE
:
1276 case MIGRATION_STATUS_SETUP
:
1277 case MIGRATION_STATUS_CANCELLING
:
1278 case MIGRATION_STATUS_CANCELLED
:
1279 case MIGRATION_STATUS_ACTIVE
:
1280 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1281 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1282 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1283 case MIGRATION_STATUS_FAILED
:
1284 case MIGRATION_STATUS_COLO
:
1285 info
->has_status
= true;
1287 case MIGRATION_STATUS_COMPLETED
:
1288 info
->has_status
= true;
1289 fill_destination_postcopy_migration_info(info
);
1292 info
->status
= mis
->state
;
1295 MigrationInfo
*qmp_query_migrate(Error
**errp
)
1297 MigrationInfo
*info
= g_malloc0(sizeof(*info
));
1299 fill_destination_migration_info(info
);
1300 fill_source_migration_info(info
);
1305 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList
*params
,
1308 MigrationState
*s
= migrate_get_current();
1309 MigrationCapabilityStatusList
*cap
;
1310 bool cap_list
[MIGRATION_CAPABILITY__MAX
];
1312 if (migration_is_running(s
->state
)) {
1313 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
1317 memcpy(cap_list
, s
->enabled_capabilities
, sizeof(cap_list
));
1318 if (!migrate_caps_check(cap_list
, params
, errp
)) {
1322 for (cap
= params
; cap
; cap
= cap
->next
) {
1323 s
->enabled_capabilities
[cap
->value
->capability
] = cap
->value
->state
;
1328 * Check whether the parameters are valid. Error will be put into errp
1329 * (if provided). Return true if valid, otherwise false.
1331 static bool migrate_params_check(MigrationParameters
*params
, Error
**errp
)
1333 if (params
->has_compress_level
&&
1334 (params
->compress_level
> 9)) {
1335 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "compress_level",
1336 "a value between 0 and 9");
1340 if (params
->has_compress_threads
&& (params
->compress_threads
< 1)) {
1341 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1343 "a value between 1 and 255");
1347 if (params
->has_decompress_threads
&& (params
->decompress_threads
< 1)) {
1348 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1349 "decompress_threads",
1350 "a value between 1 and 255");
1354 if (params
->has_throttle_trigger_threshold
&&
1355 (params
->throttle_trigger_threshold
< 1 ||
1356 params
->throttle_trigger_threshold
> 100)) {
1357 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1358 "throttle_trigger_threshold",
1359 "an integer in the range of 1 to 100");
1363 if (params
->has_cpu_throttle_initial
&&
1364 (params
->cpu_throttle_initial
< 1 ||
1365 params
->cpu_throttle_initial
> 99)) {
1366 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1367 "cpu_throttle_initial",
1368 "an integer in the range of 1 to 99");
1372 if (params
->has_cpu_throttle_increment
&&
1373 (params
->cpu_throttle_increment
< 1 ||
1374 params
->cpu_throttle_increment
> 99)) {
1375 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1376 "cpu_throttle_increment",
1377 "an integer in the range of 1 to 99");
1381 if (params
->has_max_bandwidth
&& (params
->max_bandwidth
> SIZE_MAX
)) {
1382 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1384 "an integer in the range of 0 to "stringify(SIZE_MAX
)
1389 if (params
->has_downtime_limit
&&
1390 (params
->downtime_limit
> MAX_MIGRATE_DOWNTIME
)) {
1391 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1393 "an integer in the range of 0 to "
1394 stringify(MAX_MIGRATE_DOWNTIME
)" ms");
1398 /* x_checkpoint_delay is now always positive */
1400 if (params
->has_multifd_channels
&& (params
->multifd_channels
< 1)) {
1401 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1403 "a value between 1 and 255");
1407 if (params
->has_multifd_zlib_level
&&
1408 (params
->multifd_zlib_level
> 9)) {
1409 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "multifd_zlib_level",
1410 "a value between 0 and 9");
1414 if (params
->has_multifd_zstd_level
&&
1415 (params
->multifd_zstd_level
> 20)) {
1416 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "multifd_zstd_level",
1417 "a value between 0 and 20");
1421 if (params
->has_xbzrle_cache_size
&&
1422 (params
->xbzrle_cache_size
< qemu_target_page_size() ||
1423 !is_power_of_2(params
->xbzrle_cache_size
))) {
1424 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1425 "xbzrle_cache_size",
1426 "a power of two no less than the target page size");
1430 if (params
->has_max_cpu_throttle
&&
1431 (params
->max_cpu_throttle
< params
->cpu_throttle_initial
||
1432 params
->max_cpu_throttle
> 99)) {
1433 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1435 "an integer in the range of cpu_throttle_initial to 99");
1439 if (params
->has_announce_initial
&&
1440 params
->announce_initial
> 100000) {
1441 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1443 "a value between 0 and 100000");
1446 if (params
->has_announce_max
&&
1447 params
->announce_max
> 100000) {
1448 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1450 "a value between 0 and 100000");
1453 if (params
->has_announce_rounds
&&
1454 params
->announce_rounds
> 1000) {
1455 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1457 "a value between 0 and 1000");
1460 if (params
->has_announce_step
&&
1461 (params
->announce_step
< 1 ||
1462 params
->announce_step
> 10000)) {
1463 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
1465 "a value between 0 and 10000");
1469 if (params
->has_block_bitmap_mapping
&&
1470 !check_dirty_bitmap_mig_alias_map(params
->block_bitmap_mapping
, errp
)) {
1471 error_prepend(errp
, "Invalid mapping given for block-bitmap-mapping: ");
1478 static void migrate_params_test_apply(MigrateSetParameters
*params
,
1479 MigrationParameters
*dest
)
1481 *dest
= migrate_get_current()->parameters
;
1483 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1485 if (params
->has_compress_level
) {
1486 dest
->compress_level
= params
->compress_level
;
1489 if (params
->has_compress_threads
) {
1490 dest
->compress_threads
= params
->compress_threads
;
1493 if (params
->has_compress_wait_thread
) {
1494 dest
->compress_wait_thread
= params
->compress_wait_thread
;
1497 if (params
->has_decompress_threads
) {
1498 dest
->decompress_threads
= params
->decompress_threads
;
1501 if (params
->has_throttle_trigger_threshold
) {
1502 dest
->throttle_trigger_threshold
= params
->throttle_trigger_threshold
;
1505 if (params
->has_cpu_throttle_initial
) {
1506 dest
->cpu_throttle_initial
= params
->cpu_throttle_initial
;
1509 if (params
->has_cpu_throttle_increment
) {
1510 dest
->cpu_throttle_increment
= params
->cpu_throttle_increment
;
1513 if (params
->has_cpu_throttle_tailslow
) {
1514 dest
->cpu_throttle_tailslow
= params
->cpu_throttle_tailslow
;
1517 if (params
->has_tls_creds
) {
1518 assert(params
->tls_creds
->type
== QTYPE_QSTRING
);
1519 dest
->tls_creds
= params
->tls_creds
->u
.s
;
1522 if (params
->has_tls_hostname
) {
1523 assert(params
->tls_hostname
->type
== QTYPE_QSTRING
);
1524 dest
->tls_hostname
= params
->tls_hostname
->u
.s
;
1527 if (params
->has_max_bandwidth
) {
1528 dest
->max_bandwidth
= params
->max_bandwidth
;
1531 if (params
->has_downtime_limit
) {
1532 dest
->downtime_limit
= params
->downtime_limit
;
1535 if (params
->has_x_checkpoint_delay
) {
1536 dest
->x_checkpoint_delay
= params
->x_checkpoint_delay
;
1539 if (params
->has_block_incremental
) {
1540 dest
->block_incremental
= params
->block_incremental
;
1542 if (params
->has_multifd_channels
) {
1543 dest
->multifd_channels
= params
->multifd_channels
;
1545 if (params
->has_multifd_compression
) {
1546 dest
->multifd_compression
= params
->multifd_compression
;
1548 if (params
->has_xbzrle_cache_size
) {
1549 dest
->xbzrle_cache_size
= params
->xbzrle_cache_size
;
1551 if (params
->has_max_postcopy_bandwidth
) {
1552 dest
->max_postcopy_bandwidth
= params
->max_postcopy_bandwidth
;
1554 if (params
->has_max_cpu_throttle
) {
1555 dest
->max_cpu_throttle
= params
->max_cpu_throttle
;
1557 if (params
->has_announce_initial
) {
1558 dest
->announce_initial
= params
->announce_initial
;
1560 if (params
->has_announce_max
) {
1561 dest
->announce_max
= params
->announce_max
;
1563 if (params
->has_announce_rounds
) {
1564 dest
->announce_rounds
= params
->announce_rounds
;
1566 if (params
->has_announce_step
) {
1567 dest
->announce_step
= params
->announce_step
;
1570 if (params
->has_block_bitmap_mapping
) {
1571 dest
->has_block_bitmap_mapping
= true;
1572 dest
->block_bitmap_mapping
= params
->block_bitmap_mapping
;
1576 static void migrate_params_apply(MigrateSetParameters
*params
, Error
**errp
)
1578 MigrationState
*s
= migrate_get_current();
1580 /* TODO use QAPI_CLONE() instead of duplicating it inline */
1582 if (params
->has_compress_level
) {
1583 s
->parameters
.compress_level
= params
->compress_level
;
1586 if (params
->has_compress_threads
) {
1587 s
->parameters
.compress_threads
= params
->compress_threads
;
1590 if (params
->has_compress_wait_thread
) {
1591 s
->parameters
.compress_wait_thread
= params
->compress_wait_thread
;
1594 if (params
->has_decompress_threads
) {
1595 s
->parameters
.decompress_threads
= params
->decompress_threads
;
1598 if (params
->has_throttle_trigger_threshold
) {
1599 s
->parameters
.throttle_trigger_threshold
= params
->throttle_trigger_threshold
;
1602 if (params
->has_cpu_throttle_initial
) {
1603 s
->parameters
.cpu_throttle_initial
= params
->cpu_throttle_initial
;
1606 if (params
->has_cpu_throttle_increment
) {
1607 s
->parameters
.cpu_throttle_increment
= params
->cpu_throttle_increment
;
1610 if (params
->has_cpu_throttle_tailslow
) {
1611 s
->parameters
.cpu_throttle_tailslow
= params
->cpu_throttle_tailslow
;
1614 if (params
->has_tls_creds
) {
1615 g_free(s
->parameters
.tls_creds
);
1616 assert(params
->tls_creds
->type
== QTYPE_QSTRING
);
1617 s
->parameters
.tls_creds
= g_strdup(params
->tls_creds
->u
.s
);
1620 if (params
->has_tls_hostname
) {
1621 g_free(s
->parameters
.tls_hostname
);
1622 assert(params
->tls_hostname
->type
== QTYPE_QSTRING
);
1623 s
->parameters
.tls_hostname
= g_strdup(params
->tls_hostname
->u
.s
);
1626 if (params
->has_tls_authz
) {
1627 g_free(s
->parameters
.tls_authz
);
1628 assert(params
->tls_authz
->type
== QTYPE_QSTRING
);
1629 s
->parameters
.tls_authz
= g_strdup(params
->tls_authz
->u
.s
);
1632 if (params
->has_max_bandwidth
) {
1633 s
->parameters
.max_bandwidth
= params
->max_bandwidth
;
1634 if (s
->to_dst_file
&& !migration_in_postcopy()) {
1635 qemu_file_set_rate_limit(s
->to_dst_file
,
1636 s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
);
1640 if (params
->has_downtime_limit
) {
1641 s
->parameters
.downtime_limit
= params
->downtime_limit
;
1644 if (params
->has_x_checkpoint_delay
) {
1645 s
->parameters
.x_checkpoint_delay
= params
->x_checkpoint_delay
;
1646 if (migration_in_colo_state()) {
1647 colo_checkpoint_notify(s
);
1651 if (params
->has_block_incremental
) {
1652 s
->parameters
.block_incremental
= params
->block_incremental
;
1654 if (params
->has_multifd_channels
) {
1655 s
->parameters
.multifd_channels
= params
->multifd_channels
;
1657 if (params
->has_multifd_compression
) {
1658 s
->parameters
.multifd_compression
= params
->multifd_compression
;
1660 if (params
->has_xbzrle_cache_size
) {
1661 s
->parameters
.xbzrle_cache_size
= params
->xbzrle_cache_size
;
1662 xbzrle_cache_resize(params
->xbzrle_cache_size
, errp
);
1664 if (params
->has_max_postcopy_bandwidth
) {
1665 s
->parameters
.max_postcopy_bandwidth
= params
->max_postcopy_bandwidth
;
1666 if (s
->to_dst_file
&& migration_in_postcopy()) {
1667 qemu_file_set_rate_limit(s
->to_dst_file
,
1668 s
->parameters
.max_postcopy_bandwidth
/ XFER_LIMIT_RATIO
);
1671 if (params
->has_max_cpu_throttle
) {
1672 s
->parameters
.max_cpu_throttle
= params
->max_cpu_throttle
;
1674 if (params
->has_announce_initial
) {
1675 s
->parameters
.announce_initial
= params
->announce_initial
;
1677 if (params
->has_announce_max
) {
1678 s
->parameters
.announce_max
= params
->announce_max
;
1680 if (params
->has_announce_rounds
) {
1681 s
->parameters
.announce_rounds
= params
->announce_rounds
;
1683 if (params
->has_announce_step
) {
1684 s
->parameters
.announce_step
= params
->announce_step
;
1687 if (params
->has_block_bitmap_mapping
) {
1688 qapi_free_BitmapMigrationNodeAliasList(
1689 s
->parameters
.block_bitmap_mapping
);
1691 s
->parameters
.has_block_bitmap_mapping
= true;
1692 s
->parameters
.block_bitmap_mapping
=
1693 QAPI_CLONE(BitmapMigrationNodeAliasList
,
1694 params
->block_bitmap_mapping
);
1698 void qmp_migrate_set_parameters(MigrateSetParameters
*params
, Error
**errp
)
1700 MigrationParameters tmp
;
1702 /* TODO Rewrite "" to null instead */
1703 if (params
->has_tls_creds
1704 && params
->tls_creds
->type
== QTYPE_QNULL
) {
1705 qobject_unref(params
->tls_creds
->u
.n
);
1706 params
->tls_creds
->type
= QTYPE_QSTRING
;
1707 params
->tls_creds
->u
.s
= strdup("");
1709 /* TODO Rewrite "" to null instead */
1710 if (params
->has_tls_hostname
1711 && params
->tls_hostname
->type
== QTYPE_QNULL
) {
1712 qobject_unref(params
->tls_hostname
->u
.n
);
1713 params
->tls_hostname
->type
= QTYPE_QSTRING
;
1714 params
->tls_hostname
->u
.s
= strdup("");
1717 migrate_params_test_apply(params
, &tmp
);
1719 if (!migrate_params_check(&tmp
, errp
)) {
1720 /* Invalid parameter */
1724 migrate_params_apply(params
, errp
);
1728 void qmp_migrate_start_postcopy(Error
**errp
)
1730 MigrationState
*s
= migrate_get_current();
1732 if (!migrate_postcopy()) {
1733 error_setg(errp
, "Enable postcopy with migrate_set_capability before"
1734 " the start of migration");
1738 if (s
->state
== MIGRATION_STATUS_NONE
) {
1739 error_setg(errp
, "Postcopy must be started after migration has been"
1744 * we don't error if migration has finished since that would be racy
1745 * with issuing this command.
1747 qatomic_set(&s
->start_postcopy
, true);
1750 /* shared migration helpers */
1752 void migrate_set_state(int *state
, int old_state
, int new_state
)
1754 assert(new_state
< MIGRATION_STATUS__MAX
);
1755 if (qatomic_cmpxchg(state
, old_state
, new_state
) == old_state
) {
1756 trace_migrate_set_state(MigrationStatus_str(new_state
));
1757 migrate_generate_event(new_state
);
1761 static MigrationCapabilityStatus
*migrate_cap_add(MigrationCapability index
,
1764 MigrationCapabilityStatus
*cap
;
1766 cap
= g_new0(MigrationCapabilityStatus
, 1);
1767 cap
->capability
= index
;
1773 void migrate_set_block_enabled(bool value
, Error
**errp
)
1775 MigrationCapabilityStatusList
*cap
= NULL
;
1777 QAPI_LIST_PREPEND(cap
, migrate_cap_add(MIGRATION_CAPABILITY_BLOCK
, value
));
1778 qmp_migrate_set_capabilities(cap
, errp
);
1779 qapi_free_MigrationCapabilityStatusList(cap
);
1782 static void migrate_set_block_incremental(MigrationState
*s
, bool value
)
1784 s
->parameters
.block_incremental
= value
;
1787 static void block_cleanup_parameters(MigrationState
*s
)
1789 if (s
->must_remove_block_options
) {
1790 /* setting to false can never fail */
1791 migrate_set_block_enabled(false, &error_abort
);
1792 migrate_set_block_incremental(s
, false);
1793 s
->must_remove_block_options
= false;
1797 static void migrate_fd_cleanup(MigrationState
*s
)
1799 qemu_bh_delete(s
->cleanup_bh
);
1800 s
->cleanup_bh
= NULL
;
1802 qemu_savevm_state_cleanup();
1804 if (s
->to_dst_file
) {
1807 trace_migrate_fd_cleanup();
1808 qemu_mutex_unlock_iothread();
1809 if (s
->migration_thread_running
) {
1810 qemu_thread_join(&s
->thread
);
1811 s
->migration_thread_running
= false;
1813 qemu_mutex_lock_iothread();
1815 multifd_save_cleanup();
1816 qemu_mutex_lock(&s
->qemu_file_lock
);
1817 tmp
= s
->to_dst_file
;
1818 s
->to_dst_file
= NULL
;
1819 qemu_mutex_unlock(&s
->qemu_file_lock
);
1821 * Close the file handle without the lock to make sure the
1822 * critical section won't block for long.
1824 migration_ioc_unregister_yank_from_file(tmp
);
1828 assert(!migration_is_active(s
));
1830 if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
1831 migrate_set_state(&s
->state
, MIGRATION_STATUS_CANCELLING
,
1832 MIGRATION_STATUS_CANCELLED
);
1836 /* It is used on info migrate. We can't free it */
1837 error_report_err(error_copy(s
->error
));
1839 notifier_list_notify(&migration_state_notifiers
, s
);
1840 block_cleanup_parameters(s
);
1841 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
1844 static void migrate_fd_cleanup_schedule(MigrationState
*s
)
1847 * Ref the state for bh, because it may be called when
1848 * there're already no other refs
1850 object_ref(OBJECT(s
));
1851 qemu_bh_schedule(s
->cleanup_bh
);
1854 static void migrate_fd_cleanup_bh(void *opaque
)
1856 MigrationState
*s
= opaque
;
1857 migrate_fd_cleanup(s
);
1858 object_unref(OBJECT(s
));
1861 void migrate_set_error(MigrationState
*s
, const Error
*error
)
1863 QEMU_LOCK_GUARD(&s
->error_mutex
);
1865 s
->error
= error_copy(error
);
1869 static void migrate_error_free(MigrationState
*s
)
1871 QEMU_LOCK_GUARD(&s
->error_mutex
);
1873 error_free(s
->error
);
1878 void migrate_fd_error(MigrationState
*s
, const Error
*error
)
1880 trace_migrate_fd_error(error_get_pretty(error
));
1881 assert(s
->to_dst_file
== NULL
);
1882 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1883 MIGRATION_STATUS_FAILED
);
1884 migrate_set_error(s
, error
);
1887 static void migrate_fd_cancel(MigrationState
*s
)
1890 QEMUFile
*f
= migrate_get_current()->to_dst_file
;
1891 trace_migrate_fd_cancel();
1893 WITH_QEMU_LOCK_GUARD(&s
->qemu_file_lock
) {
1894 if (s
->rp_state
.from_dst_file
) {
1895 /* shutdown the rp socket, so causing the rp thread to shutdown */
1896 qemu_file_shutdown(s
->rp_state
.from_dst_file
);
1901 old_state
= s
->state
;
1902 if (!migration_is_running(old_state
)) {
1905 /* If the migration is paused, kick it out of the pause */
1906 if (old_state
== MIGRATION_STATUS_PRE_SWITCHOVER
) {
1907 qemu_sem_post(&s
->pause_sem
);
1909 migrate_set_state(&s
->state
, old_state
, MIGRATION_STATUS_CANCELLING
);
1910 } while (s
->state
!= MIGRATION_STATUS_CANCELLING
);
1913 * If we're unlucky the migration code might be stuck somewhere in a
1914 * send/write while the network has failed and is waiting to timeout;
1915 * if we've got shutdown(2) available then we can force it to quit.
1916 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1917 * called in a bh, so there is no race against this cancel.
1919 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& f
) {
1920 qemu_file_shutdown(f
);
1922 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& s
->block_inactive
) {
1923 Error
*local_err
= NULL
;
1925 bdrv_invalidate_cache_all(&local_err
);
1927 error_report_err(local_err
);
1929 s
->block_inactive
= false;
1934 void add_migration_state_change_notifier(Notifier
*notify
)
1936 notifier_list_add(&migration_state_notifiers
, notify
);
1939 void remove_migration_state_change_notifier(Notifier
*notify
)
1941 notifier_remove(notify
);
1944 bool migration_in_setup(MigrationState
*s
)
1946 return s
->state
== MIGRATION_STATUS_SETUP
;
1949 bool migration_has_finished(MigrationState
*s
)
1951 return s
->state
== MIGRATION_STATUS_COMPLETED
;
1954 bool migration_has_failed(MigrationState
*s
)
1956 return (s
->state
== MIGRATION_STATUS_CANCELLED
||
1957 s
->state
== MIGRATION_STATUS_FAILED
);
1960 bool migration_in_postcopy(void)
1962 MigrationState
*s
= migrate_get_current();
1965 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
1966 case MIGRATION_STATUS_POSTCOPY_PAUSED
:
1967 case MIGRATION_STATUS_POSTCOPY_RECOVER
:
1974 bool migration_in_postcopy_after_devices(MigrationState
*s
)
1976 return migration_in_postcopy() && s
->postcopy_after_devices
;
1979 bool migration_in_incoming_postcopy(void)
1981 PostcopyState ps
= postcopy_state_get();
1983 return ps
>= POSTCOPY_INCOMING_DISCARD
&& ps
< POSTCOPY_INCOMING_END
;
1986 bool migration_in_bg_snapshot(void)
1988 MigrationState
*s
= migrate_get_current();
1990 return migrate_background_snapshot() &&
1991 migration_is_setup_or_active(s
->state
);
1994 bool migration_is_idle(void)
1996 MigrationState
*s
= current_migration
;
2003 case MIGRATION_STATUS_NONE
:
2004 case MIGRATION_STATUS_CANCELLED
:
2005 case MIGRATION_STATUS_COMPLETED
:
2006 case MIGRATION_STATUS_FAILED
:
2008 case MIGRATION_STATUS_SETUP
:
2009 case MIGRATION_STATUS_CANCELLING
:
2010 case MIGRATION_STATUS_ACTIVE
:
2011 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
2012 case MIGRATION_STATUS_COLO
:
2013 case MIGRATION_STATUS_PRE_SWITCHOVER
:
2014 case MIGRATION_STATUS_DEVICE
:
2015 case MIGRATION_STATUS_WAIT_UNPLUG
:
2017 case MIGRATION_STATUS__MAX
:
2018 g_assert_not_reached();
2024 bool migration_is_active(MigrationState
*s
)
2026 return (s
->state
== MIGRATION_STATUS_ACTIVE
||
2027 s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2030 void migrate_init(MigrationState
*s
)
2033 * Reinitialise all migration state, except
2034 * parameters/capabilities that the user set, and
2039 s
->to_dst_file
= NULL
;
2040 s
->state
= MIGRATION_STATUS_NONE
;
2041 s
->rp_state
.from_dst_file
= NULL
;
2042 s
->rp_state
.error
= false;
2044 s
->pages_per_second
= 0.0;
2046 s
->expected_downtime
= 0;
2048 s
->start_postcopy
= false;
2049 s
->postcopy_after_devices
= false;
2050 s
->migration_thread_running
= false;
2051 error_free(s
->error
);
2055 migrate_set_state(&s
->state
, MIGRATION_STATUS_NONE
, MIGRATION_STATUS_SETUP
);
2057 s
->start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
2059 s
->vm_was_running
= false;
2060 s
->iteration_initial_bytes
= 0;
2061 s
->threshold_size
= 0;
2064 int migrate_add_blocker_internal(Error
*reason
, Error
**errp
)
2066 /* Snapshots are similar to migrations, so check RUN_STATE_SAVE_VM too. */
2067 if (runstate_check(RUN_STATE_SAVE_VM
) || !migration_is_idle()) {
2068 error_propagate_prepend(errp
, error_copy(reason
),
2069 "disallowing migration blocker "
2070 "(migration/snapshot in progress) for: ");
2074 migration_blockers
= g_slist_prepend(migration_blockers
, reason
);
2078 int migrate_add_blocker(Error
*reason
, Error
**errp
)
2080 if (only_migratable
) {
2081 error_propagate_prepend(errp
, error_copy(reason
),
2082 "disallowing migration blocker "
2083 "(--only-migratable) for: ");
2087 return migrate_add_blocker_internal(reason
, errp
);
2090 void migrate_del_blocker(Error
*reason
)
2092 migration_blockers
= g_slist_remove(migration_blockers
, reason
);
2095 void qmp_migrate_incoming(const char *uri
, Error
**errp
)
2097 Error
*local_err
= NULL
;
2098 static bool once
= true;
2101 error_setg(errp
, "The incoming migration has already been started");
2104 if (!runstate_check(RUN_STATE_INMIGRATE
)) {
2105 error_setg(errp
, "'-incoming' was not specified on the command line");
2109 if (!yank_register_instance(MIGRATION_YANK_INSTANCE
, errp
)) {
2113 qemu_start_incoming_migration(uri
, &local_err
);
2116 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2117 error_propagate(errp
, local_err
);
2124 void qmp_migrate_recover(const char *uri
, Error
**errp
)
2126 MigrationIncomingState
*mis
= migration_incoming_get_current();
2129 * Don't even bother to use ERRP_GUARD() as it _must_ always be set by
2130 * callers (no one should ignore a recover failure); if there is, it's a
2131 * programming error.
2135 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2136 error_setg(errp
, "Migrate recover can only be run "
2137 "when postcopy is paused.");
2141 if (qatomic_cmpxchg(&mis
->postcopy_recover_triggered
,
2142 false, true) == true) {
2143 error_setg(errp
, "Migrate recovery is triggered already");
2148 * Note that this call will never start a real migration; it will
2149 * only re-setup the migration stream and poke existing migration
2150 * to continue using that newly established channel.
2152 qemu_start_incoming_migration(uri
, errp
);
2154 /* Safe to dereference with the assert above */
2156 /* Reset the flag so user could still retry */
2157 qatomic_set(&mis
->postcopy_recover_triggered
, false);
2161 void qmp_migrate_pause(Error
**errp
)
2163 MigrationState
*ms
= migrate_get_current();
2164 MigrationIncomingState
*mis
= migration_incoming_get_current();
2167 if (ms
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
2168 /* Source side, during postcopy */
2169 qemu_mutex_lock(&ms
->qemu_file_lock
);
2170 ret
= qemu_file_shutdown(ms
->to_dst_file
);
2171 qemu_mutex_unlock(&ms
->qemu_file_lock
);
2173 error_setg(errp
, "Failed to pause source migration");
2178 if (mis
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
2179 ret
= qemu_file_shutdown(mis
->from_src_file
);
2181 error_setg(errp
, "Failed to pause destination migration");
2186 error_setg(errp
, "migrate-pause is currently only supported "
2187 "during postcopy-active state");
2190 bool migration_is_blocked(Error
**errp
)
2192 if (qemu_savevm_state_blocked(errp
)) {
2196 if (migration_blockers
) {
2197 error_propagate(errp
, error_copy(migration_blockers
->data
));
2204 /* Returns true if continue to migrate, or false if error detected */
2205 static bool migrate_prepare(MigrationState
*s
, bool blk
, bool blk_inc
,
2206 bool resume
, Error
**errp
)
2208 Error
*local_err
= NULL
;
2211 if (s
->state
!= MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2212 error_setg(errp
, "Cannot resume if there is no "
2213 "paused migration");
2218 * Postcopy recovery won't work well with release-ram
2219 * capability since release-ram will drop the page buffer as
2220 * long as the page is put into the send buffer. So if there
2221 * is a network failure happened, any page buffers that have
2222 * not yet reached the destination VM but have already been
2223 * sent from the source VM will be lost forever. Let's refuse
2224 * the client from resuming such a postcopy migration.
2225 * Luckily release-ram was designed to only be used when src
2226 * and destination VMs are on the same host, so it should be
2229 if (migrate_release_ram()) {
2230 error_setg(errp
, "Postcopy recovery cannot work "
2231 "when release-ram capability is set");
2235 /* This is a resume, skip init status */
2239 if (migration_is_running(s
->state
)) {
2240 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
2244 if (runstate_check(RUN_STATE_INMIGRATE
)) {
2245 error_setg(errp
, "Guest is waiting for an incoming migration");
2249 if (runstate_check(RUN_STATE_POSTMIGRATE
)) {
2250 error_setg(errp
, "Can't migrate the vm that was paused due to "
2251 "previous migration");
2255 if (migration_is_blocked(errp
)) {
2259 if (blk
|| blk_inc
) {
2260 if (migrate_colo_enabled()) {
2261 error_setg(errp
, "No disk migration is required in COLO mode");
2264 if (migrate_use_block() || migrate_use_block_incremental()) {
2265 error_setg(errp
, "Command options are incompatible with "
2266 "current migration capabilities");
2269 migrate_set_block_enabled(true, &local_err
);
2271 error_propagate(errp
, local_err
);
2274 s
->must_remove_block_options
= true;
2278 migrate_set_block_incremental(s
, true);
2283 * set ram_counters compression_counters memory to zero for a
2286 memset(&ram_counters
, 0, sizeof(ram_counters
));
2287 memset(&compression_counters
, 0, sizeof(compression_counters
));
2292 void qmp_migrate(const char *uri
, bool has_blk
, bool blk
,
2293 bool has_inc
, bool inc
, bool has_detach
, bool detach
,
2294 bool has_resume
, bool resume
, Error
**errp
)
2296 Error
*local_err
= NULL
;
2297 MigrationState
*s
= migrate_get_current();
2298 const char *p
= NULL
;
2300 if (!migrate_prepare(s
, has_blk
&& blk
, has_inc
&& inc
,
2301 has_resume
&& resume
, errp
)) {
2302 /* Error detected, put into errp */
2306 if (!(has_resume
&& resume
)) {
2307 if (!yank_register_instance(MIGRATION_YANK_INSTANCE
, errp
)) {
2312 migrate_protocol_allow_multifd(false);
2313 if (strstart(uri
, "tcp:", &p
) ||
2314 strstart(uri
, "unix:", NULL
) ||
2315 strstart(uri
, "vsock:", NULL
)) {
2316 migrate_protocol_allow_multifd(true);
2317 socket_start_outgoing_migration(s
, p
? p
: uri
, &local_err
);
2319 } else if (strstart(uri
, "rdma:", &p
)) {
2320 rdma_start_outgoing_migration(s
, p
, &local_err
);
2322 } else if (strstart(uri
, "exec:", &p
)) {
2323 exec_start_outgoing_migration(s
, p
, &local_err
);
2324 } else if (strstart(uri
, "fd:", &p
)) {
2325 fd_start_outgoing_migration(s
, p
, &local_err
);
2327 if (!(has_resume
&& resume
)) {
2328 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2330 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "uri",
2331 "a valid migration protocol");
2332 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
2333 MIGRATION_STATUS_FAILED
);
2334 block_cleanup_parameters(s
);
2339 if (!(has_resume
&& resume
)) {
2340 yank_unregister_instance(MIGRATION_YANK_INSTANCE
);
2342 migrate_fd_error(s
, local_err
);
2343 error_propagate(errp
, local_err
);
2348 void qmp_migrate_cancel(Error
**errp
)
2350 migration_cancel(NULL
);
2353 void qmp_migrate_continue(MigrationStatus state
, Error
**errp
)
2355 MigrationState
*s
= migrate_get_current();
2356 if (s
->state
!= state
) {
2357 error_setg(errp
, "Migration not in expected state: %s",
2358 MigrationStatus_str(s
->state
));
2361 qemu_sem_post(&s
->pause_sem
);
2364 bool migrate_release_ram(void)
2368 s
= migrate_get_current();
2370 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_RELEASE_RAM
];
2373 bool migrate_postcopy_ram(void)
2377 s
= migrate_get_current();
2379 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
2382 bool migrate_postcopy(void)
2384 return migrate_postcopy_ram() || migrate_dirty_bitmaps();
2387 bool migrate_auto_converge(void)
2391 s
= migrate_get_current();
2393 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_AUTO_CONVERGE
];
2396 bool migrate_zero_blocks(void)
2400 s
= migrate_get_current();
2402 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_ZERO_BLOCKS
];
2405 bool migrate_postcopy_blocktime(void)
2409 s
= migrate_get_current();
2411 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME
];
2414 bool migrate_use_compression(void)
2418 s
= migrate_get_current();
2420 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_COMPRESS
];
2423 int migrate_compress_level(void)
2427 s
= migrate_get_current();
2429 return s
->parameters
.compress_level
;
2432 int migrate_compress_threads(void)
2436 s
= migrate_get_current();
2438 return s
->parameters
.compress_threads
;
2441 int migrate_compress_wait_thread(void)
2445 s
= migrate_get_current();
2447 return s
->parameters
.compress_wait_thread
;
2450 int migrate_decompress_threads(void)
2454 s
= migrate_get_current();
2456 return s
->parameters
.decompress_threads
;
2459 bool migrate_dirty_bitmaps(void)
2463 s
= migrate_get_current();
2465 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_DIRTY_BITMAPS
];
2468 bool migrate_ignore_shared(void)
2472 s
= migrate_get_current();
2474 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_IGNORE_SHARED
];
2477 bool migrate_validate_uuid(void)
2481 s
= migrate_get_current();
2483 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_VALIDATE_UUID
];
2486 bool migrate_use_events(void)
2490 s
= migrate_get_current();
2492 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_EVENTS
];
2495 bool migrate_use_multifd(void)
2499 s
= migrate_get_current();
2501 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_MULTIFD
];
2504 bool migrate_pause_before_switchover(void)
2508 s
= migrate_get_current();
2510 return s
->enabled_capabilities
[
2511 MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER
];
2514 int migrate_multifd_channels(void)
2518 s
= migrate_get_current();
2520 return s
->parameters
.multifd_channels
;
2523 MultiFDCompression
migrate_multifd_compression(void)
2527 s
= migrate_get_current();
2529 return s
->parameters
.multifd_compression
;
2532 int migrate_multifd_zlib_level(void)
2536 s
= migrate_get_current();
2538 return s
->parameters
.multifd_zlib_level
;
2541 int migrate_multifd_zstd_level(void)
2545 s
= migrate_get_current();
2547 return s
->parameters
.multifd_zstd_level
;
2550 int migrate_use_xbzrle(void)
2554 s
= migrate_get_current();
2556 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_XBZRLE
];
2559 uint64_t migrate_xbzrle_cache_size(void)
2563 s
= migrate_get_current();
2565 return s
->parameters
.xbzrle_cache_size
;
2568 static int64_t migrate_max_postcopy_bandwidth(void)
2572 s
= migrate_get_current();
2574 return s
->parameters
.max_postcopy_bandwidth
;
2577 bool migrate_use_block(void)
2581 s
= migrate_get_current();
2583 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_BLOCK
];
2586 bool migrate_use_return_path(void)
2590 s
= migrate_get_current();
2592 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_RETURN_PATH
];
2595 bool migrate_use_block_incremental(void)
2599 s
= migrate_get_current();
2601 return s
->parameters
.block_incremental
;
2604 bool migrate_background_snapshot(void)
2608 s
= migrate_get_current();
2610 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
];
2613 /* migration thread support */
2615 * Something bad happened to the RP stream, mark an error
2616 * The caller shall print or trace something to indicate why
2618 static void mark_source_rp_bad(MigrationState
*s
)
2620 s
->rp_state
.error
= true;
2623 static struct rp_cmd_args
{
2624 ssize_t len
; /* -1 = variable */
2627 [MIG_RP_MSG_INVALID
] = { .len
= -1, .name
= "INVALID" },
2628 [MIG_RP_MSG_SHUT
] = { .len
= 4, .name
= "SHUT" },
2629 [MIG_RP_MSG_PONG
] = { .len
= 4, .name
= "PONG" },
2630 [MIG_RP_MSG_REQ_PAGES
] = { .len
= 12, .name
= "REQ_PAGES" },
2631 [MIG_RP_MSG_REQ_PAGES_ID
] = { .len
= -1, .name
= "REQ_PAGES_ID" },
2632 [MIG_RP_MSG_RECV_BITMAP
] = { .len
= -1, .name
= "RECV_BITMAP" },
2633 [MIG_RP_MSG_RESUME_ACK
] = { .len
= 4, .name
= "RESUME_ACK" },
2634 [MIG_RP_MSG_MAX
] = { .len
= -1, .name
= "MAX" },
2638 * Process a request for pages received on the return path,
2639 * We're allowed to send more than requested (e.g. to round to our page size)
2640 * and we don't need to send pages that have already been sent.
2642 static void migrate_handle_rp_req_pages(MigrationState
*ms
, const char* rbname
,
2643 ram_addr_t start
, size_t len
)
2645 long our_host_ps
= qemu_real_host_page_size
;
2647 trace_migrate_handle_rp_req_pages(rbname
, start
, len
);
2650 * Since we currently insist on matching page sizes, just sanity check
2651 * we're being asked for whole host pages.
2653 if (!QEMU_IS_ALIGNED(start
, our_host_ps
) ||
2654 !QEMU_IS_ALIGNED(len
, our_host_ps
)) {
2655 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
2656 " len: %zd", __func__
, start
, len
);
2657 mark_source_rp_bad(ms
);
2661 if (ram_save_queue_pages(rbname
, start
, len
)) {
2662 mark_source_rp_bad(ms
);
2666 /* Return true to retry, false to quit */
2667 static bool postcopy_pause_return_path_thread(MigrationState
*s
)
2669 trace_postcopy_pause_return_path();
2671 qemu_sem_wait(&s
->postcopy_pause_rp_sem
);
2673 trace_postcopy_pause_return_path_continued();
2678 static int migrate_handle_rp_recv_bitmap(MigrationState
*s
, char *block_name
)
2680 RAMBlock
*block
= qemu_ram_block_by_name(block_name
);
2683 error_report("%s: invalid block name '%s'", __func__
, block_name
);
2687 /* Fetch the received bitmap and refresh the dirty bitmap */
2688 return ram_dirty_bitmap_reload(s
, block
);
2691 static int migrate_handle_rp_resume_ack(MigrationState
*s
, uint32_t value
)
2693 trace_source_return_path_thread_resume_ack(value
);
2695 if (value
!= MIGRATION_RESUME_ACK_VALUE
) {
2696 error_report("%s: illegal resume_ack value %"PRIu32
,
2701 /* Now both sides are active. */
2702 migrate_set_state(&s
->state
, MIGRATION_STATUS_POSTCOPY_RECOVER
,
2703 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2705 /* Notify send thread that time to continue send pages */
2706 qemu_sem_post(&s
->rp_state
.rp_sem
);
2711 /* Release ms->rp_state.from_dst_file in a safe way */
2712 static void migration_release_from_dst_file(MigrationState
*ms
)
2716 WITH_QEMU_LOCK_GUARD(&ms
->qemu_file_lock
) {
2718 * Reset the from_dst_file pointer first before releasing it, as we
2719 * can't block within lock section
2721 file
= ms
->rp_state
.from_dst_file
;
2722 ms
->rp_state
.from_dst_file
= NULL
;
2729 * Handles messages sent on the return path towards the source VM
2732 static void *source_return_path_thread(void *opaque
)
2734 MigrationState
*ms
= opaque
;
2735 QEMUFile
*rp
= ms
->rp_state
.from_dst_file
;
2736 uint16_t header_len
, header_type
;
2738 uint32_t tmp32
, sibling_error
;
2739 ram_addr_t start
= 0; /* =0 to silence warning */
2740 size_t len
= 0, expected_len
;
2743 trace_source_return_path_thread_entry();
2744 rcu_register_thread();
2747 while (!ms
->rp_state
.error
&& !qemu_file_get_error(rp
) &&
2748 migration_is_setup_or_active(ms
->state
)) {
2749 trace_source_return_path_thread_loop_top();
2750 header_type
= qemu_get_be16(rp
);
2751 header_len
= qemu_get_be16(rp
);
2753 if (qemu_file_get_error(rp
)) {
2754 mark_source_rp_bad(ms
);
2758 if (header_type
>= MIG_RP_MSG_MAX
||
2759 header_type
== MIG_RP_MSG_INVALID
) {
2760 error_report("RP: Received invalid message 0x%04x length 0x%04x",
2761 header_type
, header_len
);
2762 mark_source_rp_bad(ms
);
2766 if ((rp_cmd_args
[header_type
].len
!= -1 &&
2767 header_len
!= rp_cmd_args
[header_type
].len
) ||
2768 header_len
> sizeof(buf
)) {
2769 error_report("RP: Received '%s' message (0x%04x) with"
2770 "incorrect length %d expecting %zu",
2771 rp_cmd_args
[header_type
].name
, header_type
, header_len
,
2772 (size_t)rp_cmd_args
[header_type
].len
);
2773 mark_source_rp_bad(ms
);
2777 /* We know we've got a valid header by this point */
2778 res
= qemu_get_buffer(rp
, buf
, header_len
);
2779 if (res
!= header_len
) {
2780 error_report("RP: Failed reading data for message 0x%04x"
2781 " read %d expected %d",
2782 header_type
, res
, header_len
);
2783 mark_source_rp_bad(ms
);
2787 /* OK, we have the message and the data */
2788 switch (header_type
) {
2789 case MIG_RP_MSG_SHUT
:
2790 sibling_error
= ldl_be_p(buf
);
2791 trace_source_return_path_thread_shut(sibling_error
);
2792 if (sibling_error
) {
2793 error_report("RP: Sibling indicated error %d", sibling_error
);
2794 mark_source_rp_bad(ms
);
2797 * We'll let the main thread deal with closing the RP
2798 * we could do a shutdown(2) on it, but we're the only user
2799 * anyway, so there's nothing gained.
2803 case MIG_RP_MSG_PONG
:
2804 tmp32
= ldl_be_p(buf
);
2805 trace_source_return_path_thread_pong(tmp32
);
2808 case MIG_RP_MSG_REQ_PAGES
:
2809 start
= ldq_be_p(buf
);
2810 len
= ldl_be_p(buf
+ 8);
2811 migrate_handle_rp_req_pages(ms
, NULL
, start
, len
);
2814 case MIG_RP_MSG_REQ_PAGES_ID
:
2815 expected_len
= 12 + 1; /* header + termination */
2817 if (header_len
>= expected_len
) {
2818 start
= ldq_be_p(buf
);
2819 len
= ldl_be_p(buf
+ 8);
2820 /* Now we expect an idstr */
2821 tmp32
= buf
[12]; /* Length of the following idstr */
2822 buf
[13 + tmp32
] = '\0';
2823 expected_len
+= tmp32
;
2825 if (header_len
!= expected_len
) {
2826 error_report("RP: Req_Page_id with length %d expecting %zd",
2827 header_len
, expected_len
);
2828 mark_source_rp_bad(ms
);
2831 migrate_handle_rp_req_pages(ms
, (char *)&buf
[13], start
, len
);
2834 case MIG_RP_MSG_RECV_BITMAP
:
2835 if (header_len
< 1) {
2836 error_report("%s: missing block name", __func__
);
2837 mark_source_rp_bad(ms
);
2840 /* Format: len (1B) + idstr (<255B). This ends the idstr. */
2841 buf
[buf
[0] + 1] = '\0';
2842 if (migrate_handle_rp_recv_bitmap(ms
, (char *)(buf
+ 1))) {
2843 mark_source_rp_bad(ms
);
2848 case MIG_RP_MSG_RESUME_ACK
:
2849 tmp32
= ldl_be_p(buf
);
2850 if (migrate_handle_rp_resume_ack(ms
, tmp32
)) {
2851 mark_source_rp_bad(ms
);
2862 res
= qemu_file_get_error(rp
);
2864 if (res
== -EIO
&& migration_in_postcopy()) {
2866 * Maybe there is something we can do: it looks like a
2867 * network down issue, and we pause for a recovery.
2869 migration_release_from_dst_file(ms
);
2871 if (postcopy_pause_return_path_thread(ms
)) {
2873 * Reload rp, reset the rest. Referencing it is safe since
2874 * it's reset only by us above, or when migration completes
2876 rp
= ms
->rp_state
.from_dst_file
;
2877 ms
->rp_state
.error
= false;
2882 trace_source_return_path_thread_bad_end();
2883 mark_source_rp_bad(ms
);
2886 trace_source_return_path_thread_end();
2887 migration_release_from_dst_file(ms
);
2888 rcu_unregister_thread();
2892 static int open_return_path_on_source(MigrationState
*ms
,
2895 ms
->rp_state
.from_dst_file
= qemu_file_get_return_path(ms
->to_dst_file
);
2896 if (!ms
->rp_state
.from_dst_file
) {
2900 trace_open_return_path_on_source();
2902 if (!create_thread
) {
2907 qemu_thread_create(&ms
->rp_state
.rp_thread
, "return path",
2908 source_return_path_thread
, ms
, QEMU_THREAD_JOINABLE
);
2909 ms
->rp_state
.rp_thread_created
= true;
2911 trace_open_return_path_on_source_continue();
2916 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
2917 static int await_return_path_close_on_source(MigrationState
*ms
)
2920 * If this is a normal exit then the destination will send a SHUT and the
2921 * rp_thread will exit, however if there's an error we need to cause
2924 if (qemu_file_get_error(ms
->to_dst_file
) && ms
->rp_state
.from_dst_file
) {
2926 * shutdown(2), if we have it, will cause it to unblock if it's stuck
2927 * waiting for the destination.
2929 qemu_file_shutdown(ms
->rp_state
.from_dst_file
);
2930 mark_source_rp_bad(ms
);
2932 trace_await_return_path_close_on_source_joining();
2933 qemu_thread_join(&ms
->rp_state
.rp_thread
);
2934 ms
->rp_state
.rp_thread_created
= false;
2935 trace_await_return_path_close_on_source_close();
2936 return ms
->rp_state
.error
;
2940 * Switch from normal iteration to postcopy
2941 * Returns non-0 on error
2943 static int postcopy_start(MigrationState
*ms
)
2946 QIOChannelBuffer
*bioc
;
2948 int64_t time_at_stop
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
2949 int64_t bandwidth
= migrate_max_postcopy_bandwidth();
2950 bool restart_block
= false;
2951 int cur_state
= MIGRATION_STATUS_ACTIVE
;
2952 if (!migrate_pause_before_switchover()) {
2953 migrate_set_state(&ms
->state
, MIGRATION_STATUS_ACTIVE
,
2954 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2957 trace_postcopy_start();
2958 qemu_mutex_lock_iothread();
2959 trace_postcopy_start_set_run();
2961 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
2962 global_state_store();
2963 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
2968 ret
= migration_maybe_pause(ms
, &cur_state
,
2969 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
2974 ret
= bdrv_inactivate_all();
2978 restart_block
= true;
2981 * Cause any non-postcopiable, but iterative devices to
2982 * send out their final data.
2984 qemu_savevm_state_complete_precopy(ms
->to_dst_file
, true, false);
2987 * in Finish migrate and with the io-lock held everything should
2988 * be quiet, but we've potentially still got dirty pages and we
2989 * need to tell the destination to throw any pages it's already received
2992 if (migrate_postcopy_ram()) {
2993 if (ram_postcopy_send_discard_bitmap(ms
)) {
2994 error_report("postcopy send discard bitmap failed");
3000 * send rest of state - note things that are doing postcopy
3001 * will notice we're in POSTCOPY_ACTIVE and not actually
3002 * wrap their state up here
3004 /* 0 max-postcopy-bandwidth means unlimited */
3006 qemu_file_set_rate_limit(ms
->to_dst_file
, INT64_MAX
);
3008 qemu_file_set_rate_limit(ms
->to_dst_file
, bandwidth
/ XFER_LIMIT_RATIO
);
3010 if (migrate_postcopy_ram()) {
3011 /* Ping just for debugging, helps line traces up */
3012 qemu_savevm_send_ping(ms
->to_dst_file
, 2);
3016 * While loading the device state we may trigger page transfer
3017 * requests and the fd must be free to process those, and thus
3018 * the destination must read the whole device state off the fd before
3019 * it starts processing it. Unfortunately the ad-hoc migration format
3020 * doesn't allow the destination to know the size to read without fully
3021 * parsing it through each devices load-state code (especially the open
3022 * coded devices that use get/put).
3023 * So we wrap the device state up in a package with a length at the start;
3024 * to do this we use a qemu_buf to hold the whole of the device state.
3026 bioc
= qio_channel_buffer_new(4096);
3027 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-postcopy-buffer");
3028 fb
= qemu_fopen_channel_output(QIO_CHANNEL(bioc
));
3029 object_unref(OBJECT(bioc
));
3032 * Make sure the receiver can get incoming pages before we send the rest
3035 qemu_savevm_send_postcopy_listen(fb
);
3037 qemu_savevm_state_complete_precopy(fb
, false, false);
3038 if (migrate_postcopy_ram()) {
3039 qemu_savevm_send_ping(fb
, 3);
3042 qemu_savevm_send_postcopy_run(fb
);
3044 /* <><> end of stuff going into the package */
3046 /* Last point of recovery; as soon as we send the package the destination
3047 * can open devices and potentially start running.
3048 * Lets just check again we've not got any errors.
3050 ret
= qemu_file_get_error(ms
->to_dst_file
);
3052 error_report("postcopy_start: Migration stream errored (pre package)");
3056 restart_block
= false;
3058 /* Now send that blob */
3059 if (qemu_savevm_send_packaged(ms
->to_dst_file
, bioc
->data
, bioc
->usage
)) {
3064 /* Send a notify to give a chance for anything that needs to happen
3065 * at the transition to postcopy and after the device state; in particular
3066 * spice needs to trigger a transition now
3068 ms
->postcopy_after_devices
= true;
3069 notifier_list_notify(&migration_state_notifiers
, ms
);
3071 ms
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - time_at_stop
;
3073 qemu_mutex_unlock_iothread();
3075 if (migrate_postcopy_ram()) {
3077 * Although this ping is just for debug, it could potentially be
3078 * used for getting a better measurement of downtime at the source.
3080 qemu_savevm_send_ping(ms
->to_dst_file
, 4);
3083 if (migrate_release_ram()) {
3084 ram_postcopy_migrated_memory_release(ms
);
3087 ret
= qemu_file_get_error(ms
->to_dst_file
);
3089 error_report("postcopy_start: Migration stream errored");
3090 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
3091 MIGRATION_STATUS_FAILED
);
3099 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
3100 MIGRATION_STATUS_FAILED
);
3101 if (restart_block
) {
3102 /* A failure happened early enough that we know the destination hasn't
3103 * accessed block devices, so we're safe to recover.
3105 Error
*local_err
= NULL
;
3107 bdrv_invalidate_cache_all(&local_err
);
3109 error_report_err(local_err
);
3112 qemu_mutex_unlock_iothread();
3117 * migration_maybe_pause: Pause if required to by
3118 * migrate_pause_before_switchover called with the iothread locked
3119 * Returns: 0 on success
3121 static int migration_maybe_pause(MigrationState
*s
,
3122 int *current_active_state
,
3125 if (!migrate_pause_before_switchover()) {
3129 /* Since leaving this state is not atomic with posting the semaphore
3130 * it's possible that someone could have issued multiple migrate_continue
3131 * and the semaphore is incorrectly positive at this point;
3132 * the docs say it's undefined to reinit a semaphore that's already
3133 * init'd, so use timedwait to eat up any existing posts.
3135 while (qemu_sem_timedwait(&s
->pause_sem
, 1) == 0) {
3136 /* This block intentionally left blank */
3140 * If the migration is cancelled when it is in the completion phase,
3141 * the migration state is set to MIGRATION_STATUS_CANCELLING.
3142 * So we don't need to wait a semaphore, otherwise we would always
3143 * wait for the 'pause_sem' semaphore.
3145 if (s
->state
!= MIGRATION_STATUS_CANCELLING
) {
3146 qemu_mutex_unlock_iothread();
3147 migrate_set_state(&s
->state
, *current_active_state
,
3148 MIGRATION_STATUS_PRE_SWITCHOVER
);
3149 qemu_sem_wait(&s
->pause_sem
);
3150 migrate_set_state(&s
->state
, MIGRATION_STATUS_PRE_SWITCHOVER
,
3152 *current_active_state
= new_state
;
3153 qemu_mutex_lock_iothread();
3156 return s
->state
== new_state
? 0 : -EINVAL
;
3160 * migration_completion: Used by migration_thread when there's not much left.
3161 * The caller 'breaks' the loop when this returns.
3163 * @s: Current migration state
3165 static void migration_completion(MigrationState
*s
)
3168 int current_active_state
= s
->state
;
3170 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
3171 qemu_mutex_lock_iothread();
3172 s
->downtime_start
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3173 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
3174 s
->vm_was_running
= runstate_is_running();
3175 ret
= global_state_store();
3178 bool inactivate
= !migrate_colo_enabled();
3179 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
3180 trace_migration_completion_vm_stop(ret
);
3182 ret
= migration_maybe_pause(s
, ¤t_active_state
,
3183 MIGRATION_STATUS_DEVICE
);
3186 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
3187 ret
= qemu_savevm_state_complete_precopy(s
->to_dst_file
, false,
3190 if (inactivate
&& ret
>= 0) {
3191 s
->block_inactive
= true;
3194 qemu_mutex_unlock_iothread();
3199 } else if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
3200 trace_migration_completion_postcopy_end();
3202 qemu_mutex_lock_iothread();
3203 qemu_savevm_state_complete_postcopy(s
->to_dst_file
);
3204 qemu_mutex_unlock_iothread();
3206 trace_migration_completion_postcopy_end_after_complete();
3207 } else if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
3212 * If rp was opened we must clean up the thread before
3213 * cleaning everything else up (since if there are no failures
3214 * it will wait for the destination to send it's status in
3217 if (s
->rp_state
.rp_thread_created
) {
3219 trace_migration_return_path_end_before();
3220 rp_error
= await_return_path_close_on_source(s
);
3221 trace_migration_return_path_end_after(rp_error
);
3223 goto fail_invalidate
;
3227 if (qemu_file_get_error(s
->to_dst_file
)) {
3228 trace_migration_completion_file_err();
3229 goto fail_invalidate
;
3232 if (!migrate_colo_enabled()) {
3233 migrate_set_state(&s
->state
, current_active_state
,
3234 MIGRATION_STATUS_COMPLETED
);
3240 /* If not doing postcopy, vm_start() will be called: let's regain
3241 * control on images.
3243 if (s
->state
== MIGRATION_STATUS_ACTIVE
||
3244 s
->state
== MIGRATION_STATUS_DEVICE
) {
3245 Error
*local_err
= NULL
;
3247 qemu_mutex_lock_iothread();
3248 bdrv_invalidate_cache_all(&local_err
);
3250 error_report_err(local_err
);
3252 s
->block_inactive
= false;
3254 qemu_mutex_unlock_iothread();
3258 migrate_set_state(&s
->state
, current_active_state
,
3259 MIGRATION_STATUS_FAILED
);
3263 * bg_migration_completion: Used by bg_migration_thread when after all the
3264 * RAM has been saved. The caller 'breaks' the loop when this returns.
3266 * @s: Current migration state
3268 static void bg_migration_completion(MigrationState
*s
)
3270 int current_active_state
= s
->state
;
3273 * Stop tracking RAM writes - un-protect memory, un-register UFFD
3274 * memory ranges, flush kernel wait queues and wake up threads
3275 * waiting for write fault to be resolved.
3277 ram_write_tracking_stop();
3279 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
3281 * By this moment we have RAM content saved into the migration stream.
3282 * The next step is to flush the non-RAM content (device state)
3283 * right after the ram content. The device state has been stored into
3284 * the temporary buffer before RAM saving started.
3286 qemu_put_buffer(s
->to_dst_file
, s
->bioc
->data
, s
->bioc
->usage
);
3287 qemu_fflush(s
->to_dst_file
);
3288 } else if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
3292 if (qemu_file_get_error(s
->to_dst_file
)) {
3293 trace_migration_completion_file_err();
3297 migrate_set_state(&s
->state
, current_active_state
,
3298 MIGRATION_STATUS_COMPLETED
);
3302 migrate_set_state(&s
->state
, current_active_state
,
3303 MIGRATION_STATUS_FAILED
);
3306 bool migrate_colo_enabled(void)
3308 MigrationState
*s
= migrate_get_current();
3309 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_COLO
];
3312 typedef enum MigThrError
{
3313 /* No error detected */
3314 MIG_THR_ERR_NONE
= 0,
3315 /* Detected error, but resumed successfully */
3316 MIG_THR_ERR_RECOVERED
= 1,
3317 /* Detected fatal error, need to exit */
3318 MIG_THR_ERR_FATAL
= 2,
3321 static int postcopy_resume_handshake(MigrationState
*s
)
3323 qemu_savevm_send_postcopy_resume(s
->to_dst_file
);
3325 while (s
->state
== MIGRATION_STATUS_POSTCOPY_RECOVER
) {
3326 qemu_sem_wait(&s
->rp_state
.rp_sem
);
3329 if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
3336 /* Return zero if success, or <0 for error */
3337 static int postcopy_do_resume(MigrationState
*s
)
3342 * Call all the resume_prepare() hooks, so that modules can be
3343 * ready for the migration resume.
3345 ret
= qemu_savevm_state_resume_prepare(s
);
3347 error_report("%s: resume_prepare() failure detected: %d",
3353 * Last handshake with destination on the resume (destination will
3354 * switch to postcopy-active afterwards)
3356 ret
= postcopy_resume_handshake(s
);
3358 error_report("%s: handshake failed: %d", __func__
, ret
);
3366 * We don't return until we are in a safe state to continue current
3367 * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
3368 * MIG_THR_ERR_FATAL if unrecovery failure happened.
3370 static MigThrError
postcopy_pause(MigrationState
*s
)
3372 assert(s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
3378 * Current channel is possibly broken. Release it. Note that this is
3379 * guaranteed even without lock because to_dst_file should only be
3380 * modified by the migration thread. That also guarantees that the
3381 * unregister of yank is safe too without the lock. It should be safe
3382 * even to be within the qemu_file_lock, but we didn't do that to avoid
3383 * taking more mutex (yank_lock) within qemu_file_lock. TL;DR: we make
3384 * the qemu_file_lock critical section as small as possible.
3386 assert(s
->to_dst_file
);
3387 migration_ioc_unregister_yank_from_file(s
->to_dst_file
);
3388 qemu_mutex_lock(&s
->qemu_file_lock
);
3389 file
= s
->to_dst_file
;
3390 s
->to_dst_file
= NULL
;
3391 qemu_mutex_unlock(&s
->qemu_file_lock
);
3393 qemu_file_shutdown(file
);
3396 migrate_set_state(&s
->state
, s
->state
,
3397 MIGRATION_STATUS_POSTCOPY_PAUSED
);
3399 error_report("Detected IO failure for postcopy. "
3400 "Migration paused.");
3403 * We wait until things fixed up. Then someone will setup the
3404 * status back for us.
3406 while (s
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
3407 qemu_sem_wait(&s
->postcopy_pause_sem
);
3410 if (s
->state
== MIGRATION_STATUS_POSTCOPY_RECOVER
) {
3411 /* Woken up by a recover procedure. Give it a shot */
3414 * Firstly, let's wake up the return path now, with a new
3415 * return path channel.
3417 qemu_sem_post(&s
->postcopy_pause_rp_sem
);
3419 /* Do the resume logic */
3420 if (postcopy_do_resume(s
) == 0) {
3421 /* Let's continue! */
3422 trace_postcopy_pause_continued();
3423 return MIG_THR_ERR_RECOVERED
;
3426 * Something wrong happened during the recovery, let's
3427 * pause again. Pause is always better than throwing
3433 /* This is not right... Time to quit. */
3434 return MIG_THR_ERR_FATAL
;
3439 static MigThrError
migration_detect_error(MigrationState
*s
)
3442 int state
= s
->state
;
3443 Error
*local_error
= NULL
;
3445 if (state
== MIGRATION_STATUS_CANCELLING
||
3446 state
== MIGRATION_STATUS_CANCELLED
) {
3447 /* End the migration, but don't set the state to failed */
3448 return MIG_THR_ERR_FATAL
;
3451 /* Try to detect any file errors */
3452 ret
= qemu_file_get_error_obj(s
->to_dst_file
, &local_error
);
3454 /* Everything is fine */
3455 assert(!local_error
);
3456 return MIG_THR_ERR_NONE
;
3460 migrate_set_error(s
, local_error
);
3461 error_free(local_error
);
3464 if (state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
&& ret
== -EIO
) {
3466 * For postcopy, we allow the network to be down for a
3467 * while. After that, it can be continued by a
3470 return postcopy_pause(s
);
3473 * For precopy (or postcopy with error outside IO), we fail
3476 migrate_set_state(&s
->state
, state
, MIGRATION_STATUS_FAILED
);
3477 trace_migration_thread_file_err();
3479 /* Time to stop the migration, now. */
3480 return MIG_THR_ERR_FATAL
;
3484 /* How many bytes have we transferred since the beginning of the migration */
3485 static uint64_t migration_total_bytes(MigrationState
*s
)
3487 return qemu_ftell(s
->to_dst_file
) + ram_counters
.multifd_bytes
;
3490 static void migration_calculate_complete(MigrationState
*s
)
3492 uint64_t bytes
= migration_total_bytes(s
);
3493 int64_t end_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3494 int64_t transfer_time
;
3496 s
->total_time
= end_time
- s
->start_time
;
3499 * It's still not set, so we are precopy migration. For
3500 * postcopy, downtime is calculated during postcopy_start().
3502 s
->downtime
= end_time
- s
->downtime_start
;
3505 transfer_time
= s
->total_time
- s
->setup_time
;
3506 if (transfer_time
) {
3507 s
->mbps
= ((double) bytes
* 8.0) / transfer_time
/ 1000;
3511 static void update_iteration_initial_status(MigrationState
*s
)
3514 * Update these three fields at the same time to avoid mismatch info lead
3515 * wrong speed calculation.
3517 s
->iteration_start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3518 s
->iteration_initial_bytes
= migration_total_bytes(s
);
3519 s
->iteration_initial_pages
= ram_get_total_transferred_pages();
3522 static void migration_update_counters(MigrationState
*s
,
3523 int64_t current_time
)
3525 uint64_t transferred
, transferred_pages
, time_spent
;
3526 uint64_t current_bytes
; /* bytes transferred since the beginning */
3529 if (current_time
< s
->iteration_start_time
+ BUFFER_DELAY
) {
3533 current_bytes
= migration_total_bytes(s
);
3534 transferred
= current_bytes
- s
->iteration_initial_bytes
;
3535 time_spent
= current_time
- s
->iteration_start_time
;
3536 bandwidth
= (double)transferred
/ time_spent
;
3537 s
->threshold_size
= bandwidth
* s
->parameters
.downtime_limit
;
3539 s
->mbps
= (((double) transferred
* 8.0) /
3540 ((double) time_spent
/ 1000.0)) / 1000.0 / 1000.0;
3542 transferred_pages
= ram_get_total_transferred_pages() -
3543 s
->iteration_initial_pages
;
3544 s
->pages_per_second
= (double) transferred_pages
/
3545 (((double) time_spent
/ 1000.0));
3548 * if we haven't sent anything, we don't want to
3549 * recalculate. 10000 is a small enough number for our purposes
3551 if (ram_counters
.dirty_pages_rate
&& transferred
> 10000) {
3552 s
->expected_downtime
= ram_counters
.remaining
/ bandwidth
;
3555 qemu_file_reset_rate_limit(s
->to_dst_file
);
3557 update_iteration_initial_status(s
);
3559 trace_migrate_transferred(transferred
, time_spent
,
3560 bandwidth
, s
->threshold_size
);
3563 /* Migration thread iteration status */
3565 MIG_ITERATE_RESUME
, /* Resume current iteration */
3566 MIG_ITERATE_SKIP
, /* Skip current iteration */
3567 MIG_ITERATE_BREAK
, /* Break the loop */
3571 * Return true if continue to the next iteration directly, false
3574 static MigIterateState
migration_iteration_run(MigrationState
*s
)
3576 uint64_t pending_size
, pend_pre
, pend_compat
, pend_post
;
3577 bool in_postcopy
= s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
;
3579 qemu_savevm_state_pending(s
->to_dst_file
, s
->threshold_size
, &pend_pre
,
3580 &pend_compat
, &pend_post
);
3581 pending_size
= pend_pre
+ pend_compat
+ pend_post
;
3583 trace_migrate_pending(pending_size
, s
->threshold_size
,
3584 pend_pre
, pend_compat
, pend_post
);
3586 if (pending_size
&& pending_size
>= s
->threshold_size
) {
3587 /* Still a significant amount to transfer */
3588 if (!in_postcopy
&& pend_pre
<= s
->threshold_size
&&
3589 qatomic_read(&s
->start_postcopy
)) {
3590 if (postcopy_start(s
)) {
3591 error_report("%s: postcopy failed to start", __func__
);
3593 return MIG_ITERATE_SKIP
;
3595 /* Just another iteration step */
3596 qemu_savevm_state_iterate(s
->to_dst_file
, in_postcopy
);
3598 trace_migration_thread_low_pending(pending_size
);
3599 migration_completion(s
);
3600 return MIG_ITERATE_BREAK
;
3603 return MIG_ITERATE_RESUME
;
3606 static void migration_iteration_finish(MigrationState
*s
)
3608 /* If we enabled cpu throttling for auto-converge, turn it off. */
3609 cpu_throttle_stop();
3611 qemu_mutex_lock_iothread();
3613 case MIGRATION_STATUS_COMPLETED
:
3614 migration_calculate_complete(s
);
3615 runstate_set(RUN_STATE_POSTMIGRATE
);
3617 case MIGRATION_STATUS_COLO
:
3618 if (!migrate_colo_enabled()) {
3619 error_report("%s: critical error: calling COLO code without "
3620 "COLO enabled", __func__
);
3622 migrate_start_colo_process(s
);
3624 * Fixme: we will run VM in COLO no matter its old running state.
3625 * After exited COLO, we will keep running.
3628 case MIGRATION_STATUS_ACTIVE
:
3630 * We should really assert here, but since it's during
3631 * migration, let's try to reduce the usage of assertions.
3633 s
->vm_was_running
= true;
3635 case MIGRATION_STATUS_FAILED
:
3636 case MIGRATION_STATUS_CANCELLED
:
3637 case MIGRATION_STATUS_CANCELLING
:
3638 if (s
->vm_was_running
) {
3639 if (!runstate_check(RUN_STATE_SHUTDOWN
)) {
3643 if (runstate_check(RUN_STATE_FINISH_MIGRATE
)) {
3644 runstate_set(RUN_STATE_POSTMIGRATE
);
3650 /* Should not reach here, but if so, forgive the VM. */
3651 error_report("%s: Unknown ending state %d", __func__
, s
->state
);
3654 migrate_fd_cleanup_schedule(s
);
3655 qemu_mutex_unlock_iothread();
3658 static void bg_migration_iteration_finish(MigrationState
*s
)
3660 qemu_mutex_lock_iothread();
3662 case MIGRATION_STATUS_COMPLETED
:
3663 migration_calculate_complete(s
);
3666 case MIGRATION_STATUS_ACTIVE
:
3667 case MIGRATION_STATUS_FAILED
:
3668 case MIGRATION_STATUS_CANCELLED
:
3669 case MIGRATION_STATUS_CANCELLING
:
3673 /* Should not reach here, but if so, forgive the VM. */
3674 error_report("%s: Unknown ending state %d", __func__
, s
->state
);
3678 migrate_fd_cleanup_schedule(s
);
3679 qemu_mutex_unlock_iothread();
3683 * Return true if continue to the next iteration directly, false
3686 static MigIterateState
bg_migration_iteration_run(MigrationState
*s
)
3690 res
= qemu_savevm_state_iterate(s
->to_dst_file
, false);
3692 bg_migration_completion(s
);
3693 return MIG_ITERATE_BREAK
;
3696 return MIG_ITERATE_RESUME
;
3699 void migration_make_urgent_request(void)
3701 qemu_sem_post(&migrate_get_current()->rate_limit_sem
);
3704 void migration_consume_urgent_request(void)
3706 qemu_sem_wait(&migrate_get_current()->rate_limit_sem
);
3709 /* Returns true if the rate limiting was broken by an urgent request */
3710 bool migration_rate_limit(void)
3712 int64_t now
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3713 MigrationState
*s
= migrate_get_current();
3715 bool urgent
= false;
3716 migration_update_counters(s
, now
);
3717 if (qemu_file_rate_limit(s
->to_dst_file
)) {
3719 if (qemu_file_get_error(s
->to_dst_file
)) {
3723 * Wait for a delay to do rate limiting OR
3724 * something urgent to post the semaphore.
3726 int ms
= s
->iteration_start_time
+ BUFFER_DELAY
- now
;
3727 trace_migration_rate_limit_pre(ms
);
3728 if (qemu_sem_timedwait(&s
->rate_limit_sem
, ms
) == 0) {
3730 * We were woken by one or more urgent things but
3731 * the timedwait will have consumed one of them.
3732 * The service routine for the urgent wake will dec
3733 * the semaphore itself for each item it consumes,
3734 * so add this one we just eat back.
3736 qemu_sem_post(&s
->rate_limit_sem
);
3739 trace_migration_rate_limit_post(urgent
);
3745 * if failover devices are present, wait they are completely
3749 static void qemu_savevm_wait_unplug(MigrationState
*s
, int old_state
,
3752 if (qemu_savevm_state_guest_unplug_pending()) {
3753 migrate_set_state(&s
->state
, old_state
, MIGRATION_STATUS_WAIT_UNPLUG
);
3755 while (s
->state
== MIGRATION_STATUS_WAIT_UNPLUG
&&
3756 qemu_savevm_state_guest_unplug_pending()) {
3757 qemu_sem_timedwait(&s
->wait_unplug_sem
, 250);
3759 if (s
->state
!= MIGRATION_STATUS_WAIT_UNPLUG
) {
3760 int timeout
= 120; /* 30 seconds */
3762 * migration has been canceled
3763 * but as we have started an unplug we must wait the end
3764 * to be able to plug back the card
3766 while (timeout
-- && qemu_savevm_state_guest_unplug_pending()) {
3767 qemu_sem_timedwait(&s
->wait_unplug_sem
, 250);
3769 if (qemu_savevm_state_guest_unplug_pending()) {
3770 warn_report("migration: partially unplugged device on "
3775 migrate_set_state(&s
->state
, MIGRATION_STATUS_WAIT_UNPLUG
, new_state
);
3777 migrate_set_state(&s
->state
, old_state
, new_state
);
3782 * Master migration thread on the source VM.
3783 * It drives the migration and pumps the data down the outgoing channel.
3785 static void *migration_thread(void *opaque
)
3787 MigrationState
*s
= opaque
;
3788 int64_t setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
3789 MigThrError thr_error
;
3790 bool urgent
= false;
3792 rcu_register_thread();
3794 object_ref(OBJECT(s
));
3795 update_iteration_initial_status(s
);
3797 qemu_savevm_state_header(s
->to_dst_file
);
3800 * If we opened the return path, we need to make sure dst has it
3803 if (s
->rp_state
.rp_thread_created
) {
3804 /* Now tell the dest that it should open its end so it can reply */
3805 qemu_savevm_send_open_return_path(s
->to_dst_file
);
3807 /* And do a ping that will make stuff easier to debug */
3808 qemu_savevm_send_ping(s
->to_dst_file
, 1);
3811 if (migrate_postcopy()) {
3813 * Tell the destination that we *might* want to do postcopy later;
3814 * if the other end can't do postcopy it should fail now, nice and
3817 qemu_savevm_send_postcopy_advise(s
->to_dst_file
);
3820 if (migrate_colo_enabled()) {
3821 /* Notify migration destination that we enable COLO */
3822 qemu_savevm_send_colo_enable(s
->to_dst_file
);
3825 qemu_savevm_state_setup(s
->to_dst_file
);
3827 qemu_savevm_wait_unplug(s
, MIGRATION_STATUS_SETUP
,
3828 MIGRATION_STATUS_ACTIVE
);
3830 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
3832 trace_migration_thread_setup_complete();
3834 while (migration_is_active(s
)) {
3835 if (urgent
|| !qemu_file_rate_limit(s
->to_dst_file
)) {
3836 MigIterateState iter_state
= migration_iteration_run(s
);
3837 if (iter_state
== MIG_ITERATE_SKIP
) {
3839 } else if (iter_state
== MIG_ITERATE_BREAK
) {
3845 * Try to detect any kind of failures, and see whether we
3846 * should stop the migration now.
3848 thr_error
= migration_detect_error(s
);
3849 if (thr_error
== MIG_THR_ERR_FATAL
) {
3850 /* Stop migration */
3852 } else if (thr_error
== MIG_THR_ERR_RECOVERED
) {
3854 * Just recovered from a e.g. network failure, reset all
3855 * the local variables. This is important to avoid
3856 * breaking transferred_bytes and bandwidth calculation
3858 update_iteration_initial_status(s
);
3861 urgent
= migration_rate_limit();
3864 trace_migration_thread_after_loop();
3865 migration_iteration_finish(s
);
3866 object_unref(OBJECT(s
));
3867 rcu_unregister_thread();
3871 static void bg_migration_vm_start_bh(void *opaque
)
3873 MigrationState
*s
= opaque
;
3875 qemu_bh_delete(s
->vm_start_bh
);
3876 s
->vm_start_bh
= NULL
;
3879 s
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - s
->downtime_start
;
3883 * Background snapshot thread, based on live migration code.
3884 * This is an alternative implementation of live migration mechanism
3885 * introduced specifically to support background snapshots.
3887 * It takes advantage of userfault_fd write protection mechanism introduced
3888 * in v5.7 kernel. Compared to existing dirty page logging migration much
3889 * lesser stream traffic is produced resulting in smaller snapshot images,
3890 * simply cause of no page duplicates can get into the stream.
3892 * Another key point is that generated vmstate stream reflects machine state
3893 * 'frozen' at the beginning of snapshot creation compared to dirty page logging
3894 * mechanism, which effectively results in that saved snapshot is the state of VM
3895 * at the end of the process.
3897 static void *bg_migration_thread(void *opaque
)
3899 MigrationState
*s
= opaque
;
3900 int64_t setup_start
;
3901 MigThrError thr_error
;
3903 bool early_fail
= true;
3905 rcu_register_thread();
3906 object_ref(OBJECT(s
));
3908 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
3910 setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
3912 * We want to save vmstate for the moment when migration has been
3913 * initiated but also we want to save RAM content while VM is running.
3914 * The RAM content should appear first in the vmstate. So, we first
3915 * stash the non-RAM part of the vmstate to the temporary buffer,
3916 * then write RAM part of the vmstate to the migration stream
3917 * with vCPUs running and, finally, write stashed non-RAM part of
3918 * the vmstate from the buffer to the migration stream.
3920 s
->bioc
= qio_channel_buffer_new(512 * 1024);
3921 qio_channel_set_name(QIO_CHANNEL(s
->bioc
), "vmstate-buffer");
3922 fb
= qemu_fopen_channel_output(QIO_CHANNEL(s
->bioc
));
3923 object_unref(OBJECT(s
->bioc
));
3925 update_iteration_initial_status(s
);
3928 * Prepare for tracking memory writes with UFFD-WP - populate
3929 * RAM pages before protecting.
3932 ram_write_tracking_prepare();
3935 qemu_savevm_state_header(s
->to_dst_file
);
3936 qemu_savevm_state_setup(s
->to_dst_file
);
3938 qemu_savevm_wait_unplug(s
, MIGRATION_STATUS_SETUP
,
3939 MIGRATION_STATUS_ACTIVE
);
3941 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
3943 trace_migration_thread_setup_complete();
3944 s
->downtime_start
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
3946 qemu_mutex_lock_iothread();
3949 * If VM is currently in suspended state, then, to make a valid runstate
3950 * transition in vm_stop_force_state() we need to wakeup it up.
3952 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
, NULL
);
3953 s
->vm_was_running
= runstate_is_running();
3955 if (global_state_store()) {
3958 /* Forcibly stop VM before saving state of vCPUs and devices */
3959 if (vm_stop_force_state(RUN_STATE_PAUSED
)) {
3963 * Put vCPUs in sync with shadow context structures, then
3964 * save their state to channel-buffer along with devices.
3966 cpu_synchronize_all_states();
3967 if (qemu_savevm_state_complete_precopy_non_iterable(fb
, false, false)) {
3971 * Since we are going to get non-iterable state data directly
3972 * from s->bioc->data, explicit flush is needed here.
3976 /* Now initialize UFFD context and start tracking RAM writes */
3977 if (ram_write_tracking_start()) {
3983 * Start VM from BH handler to avoid write-fault lock here.
3984 * UFFD-WP protection for the whole RAM is already enabled so
3985 * calling VM state change notifiers from vm_start() would initiate
3986 * writes to virtio VQs memory which is in write-protected region.
3988 s
->vm_start_bh
= qemu_bh_new(bg_migration_vm_start_bh
, s
);
3989 qemu_bh_schedule(s
->vm_start_bh
);
3991 qemu_mutex_unlock_iothread();
3993 while (migration_is_active(s
)) {
3994 MigIterateState iter_state
= bg_migration_iteration_run(s
);
3995 if (iter_state
== MIG_ITERATE_SKIP
) {
3997 } else if (iter_state
== MIG_ITERATE_BREAK
) {
4002 * Try to detect any kind of failures, and see whether we
4003 * should stop the migration now.
4005 thr_error
= migration_detect_error(s
);
4006 if (thr_error
== MIG_THR_ERR_FATAL
) {
4007 /* Stop migration */
4011 migration_update_counters(s
, qemu_clock_get_ms(QEMU_CLOCK_REALTIME
));
4014 trace_migration_thread_after_loop();
4018 migrate_set_state(&s
->state
, MIGRATION_STATUS_ACTIVE
,
4019 MIGRATION_STATUS_FAILED
);
4020 qemu_mutex_unlock_iothread();
4023 bg_migration_iteration_finish(s
);
4026 object_unref(OBJECT(s
));
4027 rcu_unregister_thread();
4032 void migrate_fd_connect(MigrationState
*s
, Error
*error_in
)
4034 Error
*local_err
= NULL
;
4036 bool resume
= s
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
;
4039 * If there's a previous error, free it and prepare for another one.
4040 * Meanwhile if migration completes successfully, there won't have an error
4041 * dumped when calling migrate_fd_cleanup().
4043 migrate_error_free(s
);
4045 s
->expected_downtime
= s
->parameters
.downtime_limit
;
4047 assert(s
->cleanup_bh
);
4049 assert(!s
->cleanup_bh
);
4050 s
->cleanup_bh
= qemu_bh_new(migrate_fd_cleanup_bh
, s
);
4053 migrate_fd_error(s
, error_in
);
4056 * Don't do cleanup for resume if channel is invalid, but only dump
4057 * the error. We wait for another channel connect from the user.
4058 * The error_report still gives HMP user a hint on what failed.
4059 * It's normally done in migrate_fd_cleanup(), but call it here
4062 error_report_err(error_copy(s
->error
));
4064 migrate_fd_cleanup(s
);
4070 /* This is a resumed migration */
4071 rate_limit
= s
->parameters
.max_postcopy_bandwidth
/
4074 /* This is a fresh new migration */
4075 rate_limit
= s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
;
4077 /* Notify before starting migration thread */
4078 notifier_list_notify(&migration_state_notifiers
, s
);
4081 qemu_file_set_rate_limit(s
->to_dst_file
, rate_limit
);
4082 qemu_file_set_blocking(s
->to_dst_file
, true);
4085 * Open the return path. For postcopy, it is used exclusively. For
4086 * precopy, only if user specified "return-path" capability would
4087 * QEMU uses the return path.
4089 if (migrate_postcopy_ram() || migrate_use_return_path()) {
4090 if (open_return_path_on_source(s
, !resume
)) {
4091 error_report("Unable to open return-path for postcopy");
4092 migrate_set_state(&s
->state
, s
->state
, MIGRATION_STATUS_FAILED
);
4093 migrate_fd_cleanup(s
);
4099 /* Wakeup the main migration thread to do the recovery */
4100 migrate_set_state(&s
->state
, MIGRATION_STATUS_POSTCOPY_PAUSED
,
4101 MIGRATION_STATUS_POSTCOPY_RECOVER
);
4102 qemu_sem_post(&s
->postcopy_pause_sem
);
4106 if (multifd_save_setup(&local_err
) != 0) {
4107 error_report_err(local_err
);
4108 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
4109 MIGRATION_STATUS_FAILED
);
4110 migrate_fd_cleanup(s
);
4114 if (migrate_background_snapshot()) {
4115 qemu_thread_create(&s
->thread
, "bg_snapshot",
4116 bg_migration_thread
, s
, QEMU_THREAD_JOINABLE
);
4118 qemu_thread_create(&s
->thread
, "live_migration",
4119 migration_thread
, s
, QEMU_THREAD_JOINABLE
);
4121 s
->migration_thread_running
= true;
4124 void migration_global_dump(Monitor
*mon
)
4126 MigrationState
*ms
= migrate_get_current();
4128 monitor_printf(mon
, "globals:\n");
4129 monitor_printf(mon
, "store-global-state: %s\n",
4130 ms
->store_global_state
? "on" : "off");
4131 monitor_printf(mon
, "only-migratable: %s\n",
4132 only_migratable
? "on" : "off");
4133 monitor_printf(mon
, "send-configuration: %s\n",
4134 ms
->send_configuration
? "on" : "off");
4135 monitor_printf(mon
, "send-section-footer: %s\n",
4136 ms
->send_section_footer
? "on" : "off");
4137 monitor_printf(mon
, "decompress-error-check: %s\n",
4138 ms
->decompress_error_check
? "on" : "off");
4139 monitor_printf(mon
, "clear-bitmap-shift: %u\n",
4140 ms
->clear_bitmap_shift
);
4143 #define DEFINE_PROP_MIG_CAP(name, x) \
4144 DEFINE_PROP_BOOL(name, MigrationState, enabled_capabilities[x], false)
4146 static Property migration_properties
[] = {
4147 DEFINE_PROP_BOOL("store-global-state", MigrationState
,
4148 store_global_state
, true),
4149 DEFINE_PROP_BOOL("send-configuration", MigrationState
,
4150 send_configuration
, true),
4151 DEFINE_PROP_BOOL("send-section-footer", MigrationState
,
4152 send_section_footer
, true),
4153 DEFINE_PROP_BOOL("decompress-error-check", MigrationState
,
4154 decompress_error_check
, true),
4155 DEFINE_PROP_UINT8("x-clear-bitmap-shift", MigrationState
,
4156 clear_bitmap_shift
, CLEAR_BITMAP_SHIFT_DEFAULT
),
4158 /* Migration parameters */
4159 DEFINE_PROP_UINT8("x-compress-level", MigrationState
,
4160 parameters
.compress_level
,
4161 DEFAULT_MIGRATE_COMPRESS_LEVEL
),
4162 DEFINE_PROP_UINT8("x-compress-threads", MigrationState
,
4163 parameters
.compress_threads
,
4164 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT
),
4165 DEFINE_PROP_BOOL("x-compress-wait-thread", MigrationState
,
4166 parameters
.compress_wait_thread
, true),
4167 DEFINE_PROP_UINT8("x-decompress-threads", MigrationState
,
4168 parameters
.decompress_threads
,
4169 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT
),
4170 DEFINE_PROP_UINT8("x-throttle-trigger-threshold", MigrationState
,
4171 parameters
.throttle_trigger_threshold
,
4172 DEFAULT_MIGRATE_THROTTLE_TRIGGER_THRESHOLD
),
4173 DEFINE_PROP_UINT8("x-cpu-throttle-initial", MigrationState
,
4174 parameters
.cpu_throttle_initial
,
4175 DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL
),
4176 DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState
,
4177 parameters
.cpu_throttle_increment
,
4178 DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT
),
4179 DEFINE_PROP_BOOL("x-cpu-throttle-tailslow", MigrationState
,
4180 parameters
.cpu_throttle_tailslow
, false),
4181 DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState
,
4182 parameters
.max_bandwidth
, MAX_THROTTLE
),
4183 DEFINE_PROP_UINT64("x-downtime-limit", MigrationState
,
4184 parameters
.downtime_limit
,
4185 DEFAULT_MIGRATE_SET_DOWNTIME
),
4186 DEFINE_PROP_UINT32("x-checkpoint-delay", MigrationState
,
4187 parameters
.x_checkpoint_delay
,
4188 DEFAULT_MIGRATE_X_CHECKPOINT_DELAY
),
4189 DEFINE_PROP_UINT8("multifd-channels", MigrationState
,
4190 parameters
.multifd_channels
,
4191 DEFAULT_MIGRATE_MULTIFD_CHANNELS
),
4192 DEFINE_PROP_MULTIFD_COMPRESSION("multifd-compression", MigrationState
,
4193 parameters
.multifd_compression
,
4194 DEFAULT_MIGRATE_MULTIFD_COMPRESSION
),
4195 DEFINE_PROP_UINT8("multifd-zlib-level", MigrationState
,
4196 parameters
.multifd_zlib_level
,
4197 DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL
),
4198 DEFINE_PROP_UINT8("multifd-zstd-level", MigrationState
,
4199 parameters
.multifd_zstd_level
,
4200 DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL
),
4201 DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState
,
4202 parameters
.xbzrle_cache_size
,
4203 DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE
),
4204 DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState
,
4205 parameters
.max_postcopy_bandwidth
,
4206 DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH
),
4207 DEFINE_PROP_UINT8("max-cpu-throttle", MigrationState
,
4208 parameters
.max_cpu_throttle
,
4209 DEFAULT_MIGRATE_MAX_CPU_THROTTLE
),
4210 DEFINE_PROP_SIZE("announce-initial", MigrationState
,
4211 parameters
.announce_initial
,
4212 DEFAULT_MIGRATE_ANNOUNCE_INITIAL
),
4213 DEFINE_PROP_SIZE("announce-max", MigrationState
,
4214 parameters
.announce_max
,
4215 DEFAULT_MIGRATE_ANNOUNCE_MAX
),
4216 DEFINE_PROP_SIZE("announce-rounds", MigrationState
,
4217 parameters
.announce_rounds
,
4218 DEFAULT_MIGRATE_ANNOUNCE_ROUNDS
),
4219 DEFINE_PROP_SIZE("announce-step", MigrationState
,
4220 parameters
.announce_step
,
4221 DEFAULT_MIGRATE_ANNOUNCE_STEP
),
4223 /* Migration capabilities */
4224 DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE
),
4225 DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL
),
4226 DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE
),
4227 DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS
),
4228 DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS
),
4229 DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS
),
4230 DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM
),
4231 DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO
),
4232 DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM
),
4233 DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK
),
4234 DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH
),
4235 DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_MULTIFD
),
4236 DEFINE_PROP_MIG_CAP("x-background-snapshot",
4237 MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT
),
4239 DEFINE_PROP_END_OF_LIST(),
4242 static void migration_class_init(ObjectClass
*klass
, void *data
)
4244 DeviceClass
*dc
= DEVICE_CLASS(klass
);
4246 dc
->user_creatable
= false;
4247 device_class_set_props(dc
, migration_properties
);
4250 static void migration_instance_finalize(Object
*obj
)
4252 MigrationState
*ms
= MIGRATION_OBJ(obj
);
4253 MigrationParameters
*params
= &ms
->parameters
;
4255 qemu_mutex_destroy(&ms
->error_mutex
);
4256 qemu_mutex_destroy(&ms
->qemu_file_lock
);
4257 g_free(params
->tls_hostname
);
4258 g_free(params
->tls_creds
);
4259 qemu_sem_destroy(&ms
->wait_unplug_sem
);
4260 qemu_sem_destroy(&ms
->rate_limit_sem
);
4261 qemu_sem_destroy(&ms
->pause_sem
);
4262 qemu_sem_destroy(&ms
->postcopy_pause_sem
);
4263 qemu_sem_destroy(&ms
->postcopy_pause_rp_sem
);
4264 qemu_sem_destroy(&ms
->rp_state
.rp_sem
);
4265 error_free(ms
->error
);
4268 static void migration_instance_init(Object
*obj
)
4270 MigrationState
*ms
= MIGRATION_OBJ(obj
);
4271 MigrationParameters
*params
= &ms
->parameters
;
4273 ms
->state
= MIGRATION_STATUS_NONE
;
4275 ms
->pages_per_second
= -1;
4276 qemu_sem_init(&ms
->pause_sem
, 0);
4277 qemu_mutex_init(&ms
->error_mutex
);
4279 params
->tls_hostname
= g_strdup("");
4280 params
->tls_creds
= g_strdup("");
4282 /* Set has_* up only for parameter checks */
4283 params
->has_compress_level
= true;
4284 params
->has_compress_threads
= true;
4285 params
->has_decompress_threads
= true;
4286 params
->has_throttle_trigger_threshold
= true;
4287 params
->has_cpu_throttle_initial
= true;
4288 params
->has_cpu_throttle_increment
= true;
4289 params
->has_cpu_throttle_tailslow
= true;
4290 params
->has_max_bandwidth
= true;
4291 params
->has_downtime_limit
= true;
4292 params
->has_x_checkpoint_delay
= true;
4293 params
->has_block_incremental
= true;
4294 params
->has_multifd_channels
= true;
4295 params
->has_multifd_compression
= true;
4296 params
->has_multifd_zlib_level
= true;
4297 params
->has_multifd_zstd_level
= true;
4298 params
->has_xbzrle_cache_size
= true;
4299 params
->has_max_postcopy_bandwidth
= true;
4300 params
->has_max_cpu_throttle
= true;
4301 params
->has_announce_initial
= true;
4302 params
->has_announce_max
= true;
4303 params
->has_announce_rounds
= true;
4304 params
->has_announce_step
= true;
4306 qemu_sem_init(&ms
->postcopy_pause_sem
, 0);
4307 qemu_sem_init(&ms
->postcopy_pause_rp_sem
, 0);
4308 qemu_sem_init(&ms
->rp_state
.rp_sem
, 0);
4309 qemu_sem_init(&ms
->rate_limit_sem
, 0);
4310 qemu_sem_init(&ms
->wait_unplug_sem
, 0);
4311 qemu_mutex_init(&ms
->qemu_file_lock
);
4315 * Return true if check pass, false otherwise. Error will be put
4316 * inside errp if provided.
4318 static bool migration_object_check(MigrationState
*ms
, Error
**errp
)
4320 MigrationCapabilityStatusList
*head
= NULL
;
4321 /* Assuming all off */
4322 bool cap_list
[MIGRATION_CAPABILITY__MAX
] = { 0 }, ret
;
4325 if (!migrate_params_check(&ms
->parameters
, errp
)) {
4329 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
4330 if (ms
->enabled_capabilities
[i
]) {
4331 QAPI_LIST_PREPEND(head
, migrate_cap_add(i
, true));
4335 ret
= migrate_caps_check(cap_list
, head
, errp
);
4337 /* It works with head == NULL */
4338 qapi_free_MigrationCapabilityStatusList(head
);
4343 static const TypeInfo migration_type
= {
4344 .name
= TYPE_MIGRATION
,
4346 * NOTE: TYPE_MIGRATION is not really a device, as the object is
4347 * not created using qdev_new(), it is not attached to the qdev
4348 * device tree, and it is never realized.
4350 * TODO: Make this TYPE_OBJECT once QOM provides something like
4351 * TYPE_DEVICE's "-global" properties.
4353 .parent
= TYPE_DEVICE
,
4354 .class_init
= migration_class_init
,
4355 .class_size
= sizeof(MigrationClass
),
4356 .instance_size
= sizeof(MigrationState
),
4357 .instance_init
= migration_instance_init
,
4358 .instance_finalize
= migration_instance_finalize
,
4361 static void register_migration_types(void)
4363 type_register_static(&migration_type
);
4366 type_init(register_migration_types
);