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-common.h"
18 #include "qemu/error-report.h"
19 #include "qemu/main-loop.h"
20 #include "migration/migration.h"
21 #include "migration/qemu-file.h"
22 #include "sysemu/sysemu.h"
23 #include "block/block.h"
24 #include "qapi/qmp/qerror.h"
25 #include "qapi/util.h"
26 #include "qemu/sockets.h"
28 #include "migration/block.h"
29 #include "migration/postcopy-ram.h"
30 #include "qemu/thread.h"
31 #include "qmp-commands.h"
33 #include "qapi-event.h"
35 #include "exec/memory.h"
36 #include "exec/address-spaces.h"
38 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
40 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
42 #define BUFFER_DELAY 100
43 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
45 /* Default compression thread count */
46 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
47 /* Default decompression thread count, usually decompression is at
48 * least 4 times as fast as compression.*/
49 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
50 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
51 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
52 /* Define default autoconverge cpu throttle migration parameters */
53 #define DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL 20
54 #define DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT 10
56 /* Migration XBZRLE default cache size */
57 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
59 static NotifierList migration_state_notifiers
=
60 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers
);
62 static bool deferred_incoming
;
65 * Current state of incoming postcopy; note this is not part of
66 * MigrationIncomingState since it's state is used during cleanup
67 * at the end as MIS is being freed.
69 static PostcopyState incoming_postcopy_state
;
71 /* When we add fault tolerance, we could have several
72 migrations at once. For now we don't need to add
73 dynamic creation of migration */
76 MigrationState
*migrate_get_current(void)
79 static MigrationState current_migration
= {
80 .state
= MIGRATION_STATUS_NONE
,
81 .bandwidth_limit
= MAX_THROTTLE
,
82 .xbzrle_cache_size
= DEFAULT_MIGRATE_CACHE_SIZE
,
84 .parameters
[MIGRATION_PARAMETER_COMPRESS_LEVEL
] =
85 DEFAULT_MIGRATE_COMPRESS_LEVEL
,
86 .parameters
[MIGRATION_PARAMETER_COMPRESS_THREADS
] =
87 DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT
,
88 .parameters
[MIGRATION_PARAMETER_DECOMPRESS_THREADS
] =
89 DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT
,
90 .parameters
[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL
] =
91 DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL
,
92 .parameters
[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT
] =
93 DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT
,
97 qemu_mutex_init(¤t_migration
.src_page_req_mutex
);
100 return ¤t_migration
;
104 static MigrationIncomingState
*mis_current
;
106 MigrationIncomingState
*migration_incoming_get_current(void)
111 MigrationIncomingState
*migration_incoming_state_new(QEMUFile
* f
)
113 mis_current
= g_new0(MigrationIncomingState
, 1);
114 mis_current
->from_src_file
= f
;
115 mis_current
->state
= MIGRATION_STATUS_NONE
;
116 QLIST_INIT(&mis_current
->loadvm_handlers
);
117 qemu_mutex_init(&mis_current
->rp_mutex
);
118 qemu_event_init(&mis_current
->main_thread_load_event
, false);
123 void migration_incoming_state_destroy(void)
125 qemu_event_destroy(&mis_current
->main_thread_load_event
);
126 loadvm_free_handlers(mis_current
);
135 uint8_t runstate
[100];
140 static GlobalState global_state
;
142 int global_state_store(void)
144 if (!runstate_store((char *)global_state
.runstate
,
145 sizeof(global_state
.runstate
))) {
146 error_report("runstate name too big: %s", global_state
.runstate
);
147 trace_migrate_state_too_big();
153 void global_state_store_running(void)
155 const char *state
= RunState_lookup
[RUN_STATE_RUNNING
];
156 strncpy((char *)global_state
.runstate
,
157 state
, sizeof(global_state
.runstate
));
160 static bool global_state_received(void)
162 return global_state
.received
;
165 static RunState
global_state_get_runstate(void)
167 return global_state
.state
;
170 void global_state_set_optional(void)
172 global_state
.optional
= true;
175 static bool global_state_needed(void *opaque
)
177 GlobalState
*s
= opaque
;
178 char *runstate
= (char *)s
->runstate
;
180 /* If it is not optional, it is mandatory */
182 if (s
->optional
== false) {
186 /* If state is running or paused, it is not needed */
188 if (strcmp(runstate
, "running") == 0 ||
189 strcmp(runstate
, "paused") == 0) {
193 /* for any other state it is needed */
197 static int global_state_post_load(void *opaque
, int version_id
)
199 GlobalState
*s
= opaque
;
200 Error
*local_err
= NULL
;
202 char *runstate
= (char *)s
->runstate
;
205 trace_migrate_global_state_post_load(runstate
);
207 r
= qapi_enum_parse(RunState_lookup
, runstate
, RUN_STATE__MAX
,
212 error_report_err(local_err
);
221 static void global_state_pre_save(void *opaque
)
223 GlobalState
*s
= opaque
;
225 trace_migrate_global_state_pre_save((char *)s
->runstate
);
226 s
->size
= strlen((char *)s
->runstate
) + 1;
229 static const VMStateDescription vmstate_globalstate
= {
230 .name
= "globalstate",
232 .minimum_version_id
= 1,
233 .post_load
= global_state_post_load
,
234 .pre_save
= global_state_pre_save
,
235 .needed
= global_state_needed
,
236 .fields
= (VMStateField
[]) {
237 VMSTATE_UINT32(size
, GlobalState
),
238 VMSTATE_BUFFER(runstate
, GlobalState
),
239 VMSTATE_END_OF_LIST()
243 void register_global_state(void)
245 /* We would use it independently that we receive it */
246 strcpy((char *)&global_state
.runstate
, "");
247 global_state
.received
= false;
248 vmstate_register(NULL
, 0, &vmstate_globalstate
, &global_state
);
251 static void migrate_generate_event(int new_state
)
253 if (migrate_use_events()) {
254 qapi_event_send_migration(new_state
, &error_abort
);
259 * Called on -incoming with a defer: uri.
260 * The migration can be started later after any parameters have been
263 static void deferred_incoming_migration(Error
**errp
)
265 if (deferred_incoming
) {
266 error_setg(errp
, "Incoming migration already deferred");
268 deferred_incoming
= true;
271 /* Request a range of pages from the source VM at the given
273 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
274 * as the last request (a name must have been given previously)
275 * Start: Address offset within the RB
276 * Len: Length in bytes required - must be a multiple of pagesize
278 void migrate_send_rp_req_pages(MigrationIncomingState
*mis
, const char *rbname
,
279 ram_addr_t start
, size_t len
)
281 uint8_t bufc
[12 + 1 + 255]; /* start (8), len (4), rbname upto 256 */
282 size_t msglen
= 12; /* start + len */
284 *(uint64_t *)bufc
= cpu_to_be64((uint64_t)start
);
285 *(uint32_t *)(bufc
+ 8) = cpu_to_be32((uint32_t)len
);
288 int rbname_len
= strlen(rbname
);
289 assert(rbname_len
< 256);
291 bufc
[msglen
++] = rbname_len
;
292 memcpy(bufc
+ msglen
, rbname
, rbname_len
);
293 msglen
+= rbname_len
;
294 migrate_send_rp_message(mis
, MIG_RP_MSG_REQ_PAGES_ID
, msglen
, bufc
);
296 migrate_send_rp_message(mis
, MIG_RP_MSG_REQ_PAGES
, msglen
, bufc
);
300 void qemu_start_incoming_migration(const char *uri
, Error
**errp
)
304 qapi_event_send_migration(MIGRATION_STATUS_SETUP
, &error_abort
);
305 if (!strcmp(uri
, "defer")) {
306 deferred_incoming_migration(errp
);
307 } else if (strstart(uri
, "tcp:", &p
)) {
308 tcp_start_incoming_migration(p
, errp
);
310 } else if (strstart(uri
, "rdma:", &p
)) {
311 rdma_start_incoming_migration(p
, errp
);
314 } else if (strstart(uri
, "exec:", &p
)) {
315 exec_start_incoming_migration(p
, errp
);
316 } else if (strstart(uri
, "unix:", &p
)) {
317 unix_start_incoming_migration(p
, errp
);
318 } else if (strstart(uri
, "fd:", &p
)) {
319 fd_start_incoming_migration(p
, errp
);
322 error_setg(errp
, "unknown migration protocol: %s", uri
);
326 static void process_incoming_migration_co(void *opaque
)
328 QEMUFile
*f
= opaque
;
329 Error
*local_err
= NULL
;
330 MigrationIncomingState
*mis
;
334 mis
= migration_incoming_state_new(f
);
335 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
336 migrate_set_state(&mis
->state
, MIGRATION_STATUS_NONE
,
337 MIGRATION_STATUS_ACTIVE
);
338 ret
= qemu_loadvm_state(f
);
340 ps
= postcopy_state_get();
341 trace_process_incoming_migration_co_end(ret
, ps
);
342 if (ps
!= POSTCOPY_INCOMING_NONE
) {
343 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
345 * Where a migration had postcopy enabled (and thus went to advise)
346 * but managed to complete within the precopy period, we can use
349 postcopy_ram_incoming_cleanup(mis
);
350 } else if (ret
>= 0) {
352 * Postcopy was started, cleanup should happen at the end of the
355 trace_process_incoming_migration_co_postcopy_end_main();
358 /* Else if something went wrong then just fall out of the normal exit */
362 free_xbzrle_decoded_buf();
365 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
366 MIGRATION_STATUS_FAILED
);
367 error_report("load of migration failed: %s", strerror(-ret
));
368 migrate_decompress_threads_join();
372 /* Make sure all file formats flush their mutable metadata */
373 bdrv_invalidate_cache_all(&local_err
);
375 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
376 MIGRATION_STATUS_FAILED
);
377 error_report_err(local_err
);
378 migrate_decompress_threads_join();
383 * This must happen after all error conditions are dealt with and
384 * we're sure the VM is going to be running on this host.
386 qemu_announce_self();
388 /* If global state section was not received or we are in running
389 state, we need to obey autostart. Any other state is set with
392 if (!global_state_received() ||
393 global_state_get_runstate() == RUN_STATE_RUNNING
) {
397 runstate_set(RUN_STATE_PAUSED
);
400 runstate_set(global_state_get_runstate());
402 migrate_decompress_threads_join();
404 * This must happen after any state changes since as soon as an external
405 * observer sees this event they might start to prod at the VM assuming
408 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
409 MIGRATION_STATUS_COMPLETED
);
410 migration_incoming_state_destroy();
413 void process_incoming_migration(QEMUFile
*f
)
415 Coroutine
*co
= qemu_coroutine_create(process_incoming_migration_co
);
416 int fd
= qemu_get_fd(f
);
419 migrate_decompress_threads_create();
420 qemu_set_nonblock(fd
);
421 qemu_coroutine_enter(co
, f
);
425 * Send a message on the return channel back to the source
428 void migrate_send_rp_message(MigrationIncomingState
*mis
,
429 enum mig_rp_message_type message_type
,
430 uint16_t len
, void *data
)
432 trace_migrate_send_rp_message((int)message_type
, len
);
433 qemu_mutex_lock(&mis
->rp_mutex
);
434 qemu_put_be16(mis
->to_src_file
, (unsigned int)message_type
);
435 qemu_put_be16(mis
->to_src_file
, len
);
436 qemu_put_buffer(mis
->to_src_file
, data
, len
);
437 qemu_fflush(mis
->to_src_file
);
438 qemu_mutex_unlock(&mis
->rp_mutex
);
442 * Send a 'SHUT' message on the return channel with the given value
443 * to indicate that we've finished with the RP. Non-0 value indicates
446 void migrate_send_rp_shut(MigrationIncomingState
*mis
,
451 buf
= cpu_to_be32(value
);
452 migrate_send_rp_message(mis
, MIG_RP_MSG_SHUT
, sizeof(buf
), &buf
);
456 * Send a 'PONG' message on the return channel with the given value
457 * (normally in response to a 'PING')
459 void migrate_send_rp_pong(MigrationIncomingState
*mis
,
464 buf
= cpu_to_be32(value
);
465 migrate_send_rp_message(mis
, MIG_RP_MSG_PONG
, sizeof(buf
), &buf
);
468 /* amount of nanoseconds we are willing to wait for migration to be down.
469 * the choice of nanoseconds is because it is the maximum resolution that
470 * get_clock() can achieve. It is an internal measure. All user-visible
471 * units must be in seconds */
472 static uint64_t max_downtime
= 300000000;
474 uint64_t migrate_max_downtime(void)
479 MigrationCapabilityStatusList
*qmp_query_migrate_capabilities(Error
**errp
)
481 MigrationCapabilityStatusList
*head
= NULL
;
482 MigrationCapabilityStatusList
*caps
;
483 MigrationState
*s
= migrate_get_current();
486 caps
= NULL
; /* silence compiler warning */
487 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
489 head
= g_malloc0(sizeof(*caps
));
492 caps
->next
= g_malloc0(sizeof(*caps
));
496 g_malloc(sizeof(*caps
->value
));
497 caps
->value
->capability
= i
;
498 caps
->value
->state
= s
->enabled_capabilities
[i
];
504 MigrationParameters
*qmp_query_migrate_parameters(Error
**errp
)
506 MigrationParameters
*params
;
507 MigrationState
*s
= migrate_get_current();
509 params
= g_malloc0(sizeof(*params
));
510 params
->compress_level
= s
->parameters
[MIGRATION_PARAMETER_COMPRESS_LEVEL
];
511 params
->compress_threads
=
512 s
->parameters
[MIGRATION_PARAMETER_COMPRESS_THREADS
];
513 params
->decompress_threads
=
514 s
->parameters
[MIGRATION_PARAMETER_DECOMPRESS_THREADS
];
515 params
->x_cpu_throttle_initial
=
516 s
->parameters
[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL
];
517 params
->x_cpu_throttle_increment
=
518 s
->parameters
[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT
];
524 * Return true if we're already in the middle of a migration
525 * (i.e. any of the active or setup states)
527 static bool migration_is_setup_or_active(int state
)
530 case MIGRATION_STATUS_ACTIVE
:
531 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
532 case MIGRATION_STATUS_SETUP
:
541 static void get_xbzrle_cache_stats(MigrationInfo
*info
)
543 if (migrate_use_xbzrle()) {
544 info
->has_xbzrle_cache
= true;
545 info
->xbzrle_cache
= g_malloc0(sizeof(*info
->xbzrle_cache
));
546 info
->xbzrle_cache
->cache_size
= migrate_xbzrle_cache_size();
547 info
->xbzrle_cache
->bytes
= xbzrle_mig_bytes_transferred();
548 info
->xbzrle_cache
->pages
= xbzrle_mig_pages_transferred();
549 info
->xbzrle_cache
->cache_miss
= xbzrle_mig_pages_cache_miss();
550 info
->xbzrle_cache
->cache_miss_rate
= xbzrle_mig_cache_miss_rate();
551 info
->xbzrle_cache
->overflow
= xbzrle_mig_pages_overflow();
555 MigrationInfo
*qmp_query_migrate(Error
**errp
)
557 MigrationInfo
*info
= g_malloc0(sizeof(*info
));
558 MigrationState
*s
= migrate_get_current();
561 case MIGRATION_STATUS_NONE
:
562 /* no migration has happened ever */
564 case MIGRATION_STATUS_SETUP
:
565 info
->has_status
= true;
566 info
->has_total_time
= false;
568 case MIGRATION_STATUS_ACTIVE
:
569 case MIGRATION_STATUS_CANCELLING
:
570 info
->has_status
= true;
571 info
->has_total_time
= true;
572 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
)
574 info
->has_expected_downtime
= true;
575 info
->expected_downtime
= s
->expected_downtime
;
576 info
->has_setup_time
= true;
577 info
->setup_time
= s
->setup_time
;
579 info
->has_ram
= true;
580 info
->ram
= g_malloc0(sizeof(*info
->ram
));
581 info
->ram
->transferred
= ram_bytes_transferred();
582 info
->ram
->remaining
= ram_bytes_remaining();
583 info
->ram
->total
= ram_bytes_total();
584 info
->ram
->duplicate
= dup_mig_pages_transferred();
585 info
->ram
->skipped
= skipped_mig_pages_transferred();
586 info
->ram
->normal
= norm_mig_pages_transferred();
587 info
->ram
->normal_bytes
= norm_mig_bytes_transferred();
588 info
->ram
->dirty_pages_rate
= s
->dirty_pages_rate
;
589 info
->ram
->mbps
= s
->mbps
;
590 info
->ram
->dirty_sync_count
= s
->dirty_sync_count
;
592 if (blk_mig_active()) {
593 info
->has_disk
= true;
594 info
->disk
= g_malloc0(sizeof(*info
->disk
));
595 info
->disk
->transferred
= blk_mig_bytes_transferred();
596 info
->disk
->remaining
= blk_mig_bytes_remaining();
597 info
->disk
->total
= blk_mig_bytes_total();
600 if (cpu_throttle_active()) {
601 info
->has_x_cpu_throttle_percentage
= true;
602 info
->x_cpu_throttle_percentage
= cpu_throttle_get_percentage();
605 get_xbzrle_cache_stats(info
);
607 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
608 /* Mostly the same as active; TODO add some postcopy stats */
609 info
->has_status
= true;
610 info
->has_total_time
= true;
611 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
)
613 info
->has_expected_downtime
= true;
614 info
->expected_downtime
= s
->expected_downtime
;
615 info
->has_setup_time
= true;
616 info
->setup_time
= s
->setup_time
;
618 info
->has_ram
= true;
619 info
->ram
= g_malloc0(sizeof(*info
->ram
));
620 info
->ram
->transferred
= ram_bytes_transferred();
621 info
->ram
->remaining
= ram_bytes_remaining();
622 info
->ram
->total
= ram_bytes_total();
623 info
->ram
->duplicate
= dup_mig_pages_transferred();
624 info
->ram
->skipped
= skipped_mig_pages_transferred();
625 info
->ram
->normal
= norm_mig_pages_transferred();
626 info
->ram
->normal_bytes
= norm_mig_bytes_transferred();
627 info
->ram
->dirty_pages_rate
= s
->dirty_pages_rate
;
628 info
->ram
->mbps
= s
->mbps
;
630 if (blk_mig_active()) {
631 info
->has_disk
= true;
632 info
->disk
= g_malloc0(sizeof(*info
->disk
));
633 info
->disk
->transferred
= blk_mig_bytes_transferred();
634 info
->disk
->remaining
= blk_mig_bytes_remaining();
635 info
->disk
->total
= blk_mig_bytes_total();
638 get_xbzrle_cache_stats(info
);
640 case MIGRATION_STATUS_COMPLETED
:
641 get_xbzrle_cache_stats(info
);
643 info
->has_status
= true;
644 info
->has_total_time
= true;
645 info
->total_time
= s
->total_time
;
646 info
->has_downtime
= true;
647 info
->downtime
= s
->downtime
;
648 info
->has_setup_time
= true;
649 info
->setup_time
= s
->setup_time
;
651 info
->has_ram
= true;
652 info
->ram
= g_malloc0(sizeof(*info
->ram
));
653 info
->ram
->transferred
= ram_bytes_transferred();
654 info
->ram
->remaining
= 0;
655 info
->ram
->total
= ram_bytes_total();
656 info
->ram
->duplicate
= dup_mig_pages_transferred();
657 info
->ram
->skipped
= skipped_mig_pages_transferred();
658 info
->ram
->normal
= norm_mig_pages_transferred();
659 info
->ram
->normal_bytes
= norm_mig_bytes_transferred();
660 info
->ram
->mbps
= s
->mbps
;
661 info
->ram
->dirty_sync_count
= s
->dirty_sync_count
;
663 case MIGRATION_STATUS_FAILED
:
664 info
->has_status
= true;
666 case MIGRATION_STATUS_CANCELLED
:
667 info
->has_status
= true;
670 info
->status
= s
->state
;
675 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList
*params
,
678 MigrationState
*s
= migrate_get_current();
679 MigrationCapabilityStatusList
*cap
;
681 if (migration_is_setup_or_active(s
->state
)) {
682 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
686 for (cap
= params
; cap
; cap
= cap
->next
) {
687 s
->enabled_capabilities
[cap
->value
->capability
] = cap
->value
->state
;
690 if (migrate_postcopy_ram()) {
691 if (migrate_use_compression()) {
692 /* The decompression threads asynchronously write into RAM
693 * rather than use the atomic copies needed to avoid
694 * userfaulting. It should be possible to fix the decompression
695 * threads for compatibility in future.
697 error_report("Postcopy is not currently compatible with "
699 s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_POSTCOPY_RAM
] =
705 void qmp_migrate_set_parameters(bool has_compress_level
,
706 int64_t compress_level
,
707 bool has_compress_threads
,
708 int64_t compress_threads
,
709 bool has_decompress_threads
,
710 int64_t decompress_threads
,
711 bool has_x_cpu_throttle_initial
,
712 int64_t x_cpu_throttle_initial
,
713 bool has_x_cpu_throttle_increment
,
714 int64_t x_cpu_throttle_increment
, Error
**errp
)
716 MigrationState
*s
= migrate_get_current();
718 if (has_compress_level
&& (compress_level
< 0 || compress_level
> 9)) {
719 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "compress_level",
720 "is invalid, it should be in the range of 0 to 9");
723 if (has_compress_threads
&&
724 (compress_threads
< 1 || compress_threads
> 255)) {
725 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
727 "is invalid, it should be in the range of 1 to 255");
730 if (has_decompress_threads
&&
731 (decompress_threads
< 1 || decompress_threads
> 255)) {
732 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
733 "decompress_threads",
734 "is invalid, it should be in the range of 1 to 255");
737 if (has_x_cpu_throttle_initial
&&
738 (x_cpu_throttle_initial
< 1 || x_cpu_throttle_initial
> 99)) {
739 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
740 "x_cpu_throttle_initial",
741 "an integer in the range of 1 to 99");
743 if (has_x_cpu_throttle_increment
&&
744 (x_cpu_throttle_increment
< 1 || x_cpu_throttle_increment
> 99)) {
745 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
746 "x_cpu_throttle_increment",
747 "an integer in the range of 1 to 99");
750 if (has_compress_level
) {
751 s
->parameters
[MIGRATION_PARAMETER_COMPRESS_LEVEL
] = compress_level
;
753 if (has_compress_threads
) {
754 s
->parameters
[MIGRATION_PARAMETER_COMPRESS_THREADS
] = compress_threads
;
756 if (has_decompress_threads
) {
757 s
->parameters
[MIGRATION_PARAMETER_DECOMPRESS_THREADS
] =
760 if (has_x_cpu_throttle_initial
) {
761 s
->parameters
[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL
] =
762 x_cpu_throttle_initial
;
765 if (has_x_cpu_throttle_increment
) {
766 s
->parameters
[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT
] =
767 x_cpu_throttle_increment
;
771 void qmp_migrate_start_postcopy(Error
**errp
)
773 MigrationState
*s
= migrate_get_current();
775 if (!migrate_postcopy_ram()) {
776 error_setg(errp
, "Enable postcopy with migrate_set_capability before"
777 " the start of migration");
781 if (s
->state
== MIGRATION_STATUS_NONE
) {
782 error_setg(errp
, "Postcopy must be started after migration has been"
787 * we don't error if migration has finished since that would be racy
788 * with issuing this command.
790 atomic_set(&s
->start_postcopy
, true);
793 /* shared migration helpers */
795 void migrate_set_state(int *state
, int old_state
, int new_state
)
797 if (atomic_cmpxchg(state
, old_state
, new_state
) == old_state
) {
798 trace_migrate_set_state(new_state
);
799 migrate_generate_event(new_state
);
803 static void migrate_fd_cleanup(void *opaque
)
805 MigrationState
*s
= opaque
;
807 qemu_bh_delete(s
->cleanup_bh
);
808 s
->cleanup_bh
= NULL
;
813 trace_migrate_fd_cleanup();
814 qemu_mutex_unlock_iothread();
815 if (s
->migration_thread_running
) {
816 qemu_thread_join(&s
->thread
);
817 s
->migration_thread_running
= false;
819 qemu_mutex_lock_iothread();
821 migrate_compress_threads_join();
822 qemu_fclose(s
->file
);
826 assert((s
->state
!= MIGRATION_STATUS_ACTIVE
) &&
827 (s
->state
!= MIGRATION_STATUS_POSTCOPY_ACTIVE
));
829 if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
830 migrate_set_state(&s
->state
, MIGRATION_STATUS_CANCELLING
,
831 MIGRATION_STATUS_CANCELLED
);
834 notifier_list_notify(&migration_state_notifiers
, s
);
837 void migrate_fd_error(MigrationState
*s
)
839 trace_migrate_fd_error();
840 assert(s
->file
== NULL
);
841 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
842 MIGRATION_STATUS_FAILED
);
843 notifier_list_notify(&migration_state_notifiers
, s
);
846 static void migrate_fd_cancel(MigrationState
*s
)
849 QEMUFile
*f
= migrate_get_current()->file
;
850 trace_migrate_fd_cancel();
852 if (s
->rp_state
.from_dst_file
) {
853 /* shutdown the rp socket, so causing the rp thread to shutdown */
854 qemu_file_shutdown(s
->rp_state
.from_dst_file
);
858 old_state
= s
->state
;
859 if (!migration_is_setup_or_active(old_state
)) {
862 migrate_set_state(&s
->state
, old_state
, MIGRATION_STATUS_CANCELLING
);
863 } while (s
->state
!= MIGRATION_STATUS_CANCELLING
);
866 * If we're unlucky the migration code might be stuck somewhere in a
867 * send/write while the network has failed and is waiting to timeout;
868 * if we've got shutdown(2) available then we can force it to quit.
869 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
870 * called in a bh, so there is no race against this cancel.
872 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& f
) {
873 qemu_file_shutdown(f
);
877 void add_migration_state_change_notifier(Notifier
*notify
)
879 notifier_list_add(&migration_state_notifiers
, notify
);
882 void remove_migration_state_change_notifier(Notifier
*notify
)
884 notifier_remove(notify
);
887 bool migration_in_setup(MigrationState
*s
)
889 return s
->state
== MIGRATION_STATUS_SETUP
;
892 bool migration_has_finished(MigrationState
*s
)
894 return s
->state
== MIGRATION_STATUS_COMPLETED
;
897 bool migration_has_failed(MigrationState
*s
)
899 return (s
->state
== MIGRATION_STATUS_CANCELLED
||
900 s
->state
== MIGRATION_STATUS_FAILED
);
903 bool migration_in_postcopy(MigrationState
*s
)
905 return (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
908 MigrationState
*migrate_init(const MigrationParams
*params
)
910 MigrationState
*s
= migrate_get_current();
913 * Reinitialise all migration state, except
914 * parameters/capabilities that the user set, and
921 s
->state
= MIGRATION_STATUS_NONE
;
923 s
->rp_state
.from_dst_file
= NULL
;
924 s
->rp_state
.error
= false;
927 s
->expected_downtime
= 0;
928 s
->dirty_pages_rate
= 0;
929 s
->dirty_bytes_rate
= 0;
931 s
->dirty_sync_count
= 0;
932 s
->start_postcopy
= false;
933 s
->migration_thread_running
= false;
934 s
->last_req_rb
= NULL
;
936 migrate_set_state(&s
->state
, MIGRATION_STATUS_NONE
, MIGRATION_STATUS_SETUP
);
938 QSIMPLEQ_INIT(&s
->src_page_requests
);
940 s
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
944 static GSList
*migration_blockers
;
946 void migrate_add_blocker(Error
*reason
)
948 migration_blockers
= g_slist_prepend(migration_blockers
, reason
);
951 void migrate_del_blocker(Error
*reason
)
953 migration_blockers
= g_slist_remove(migration_blockers
, reason
);
956 void qmp_migrate_incoming(const char *uri
, Error
**errp
)
958 Error
*local_err
= NULL
;
959 static bool once
= true;
961 if (!deferred_incoming
) {
962 error_setg(errp
, "For use with '-incoming defer'");
966 error_setg(errp
, "The incoming migration has already been started");
969 qemu_start_incoming_migration(uri
, &local_err
);
972 error_propagate(errp
, local_err
);
979 void qmp_migrate(const char *uri
, bool has_blk
, bool blk
,
980 bool has_inc
, bool inc
, bool has_detach
, bool detach
,
983 Error
*local_err
= NULL
;
984 MigrationState
*s
= migrate_get_current();
985 MigrationParams params
;
988 params
.blk
= has_blk
&& blk
;
989 params
.shared
= has_inc
&& inc
;
991 if (migration_is_setup_or_active(s
->state
) ||
992 s
->state
== MIGRATION_STATUS_CANCELLING
) {
993 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
996 if (runstate_check(RUN_STATE_INMIGRATE
)) {
997 error_setg(errp
, "Guest is waiting for an incoming migration");
1001 if (qemu_savevm_state_blocked(errp
)) {
1005 if (migration_blockers
) {
1006 *errp
= error_copy(migration_blockers
->data
);
1010 /* We are starting a new migration, so we want to start in a clean
1011 state. This change is only needed if previous migration
1012 failed/was cancelled. We don't use migrate_set_state() because
1013 we are setting the initial state, not changing it. */
1014 s
->state
= MIGRATION_STATUS_NONE
;
1016 s
= migrate_init(¶ms
);
1018 if (strstart(uri
, "tcp:", &p
)) {
1019 tcp_start_outgoing_migration(s
, p
, &local_err
);
1021 } else if (strstart(uri
, "rdma:", &p
)) {
1022 rdma_start_outgoing_migration(s
, p
, &local_err
);
1025 } else if (strstart(uri
, "exec:", &p
)) {
1026 exec_start_outgoing_migration(s
, p
, &local_err
);
1027 } else if (strstart(uri
, "unix:", &p
)) {
1028 unix_start_outgoing_migration(s
, p
, &local_err
);
1029 } else if (strstart(uri
, "fd:", &p
)) {
1030 fd_start_outgoing_migration(s
, p
, &local_err
);
1033 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "uri",
1034 "a valid migration protocol");
1035 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1036 MIGRATION_STATUS_FAILED
);
1041 migrate_fd_error(s
);
1042 error_propagate(errp
, local_err
);
1047 void qmp_migrate_cancel(Error
**errp
)
1049 migrate_fd_cancel(migrate_get_current());
1052 void qmp_migrate_set_cache_size(int64_t value
, Error
**errp
)
1054 MigrationState
*s
= migrate_get_current();
1057 /* Check for truncation */
1058 if (value
!= (size_t)value
) {
1059 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "cache size",
1060 "exceeding address space");
1064 /* Cache should not be larger than guest ram size */
1065 if (value
> ram_bytes_total()) {
1066 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "cache size",
1067 "exceeds guest ram size ");
1071 new_size
= xbzrle_cache_resize(value
);
1073 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "cache size",
1074 "is smaller than page size");
1078 s
->xbzrle_cache_size
= new_size
;
1081 int64_t qmp_query_migrate_cache_size(Error
**errp
)
1083 return migrate_xbzrle_cache_size();
1086 void qmp_migrate_set_speed(int64_t value
, Error
**errp
)
1093 if (value
> SIZE_MAX
) {
1097 s
= migrate_get_current();
1098 s
->bandwidth_limit
= value
;
1100 qemu_file_set_rate_limit(s
->file
, s
->bandwidth_limit
/ XFER_LIMIT_RATIO
);
1104 void qmp_migrate_set_downtime(double value
, Error
**errp
)
1107 value
= MAX(0, MIN(UINT64_MAX
, value
));
1108 max_downtime
= (uint64_t)value
;
1111 bool migrate_postcopy_ram(void)
1115 s
= migrate_get_current();
1117 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_POSTCOPY_RAM
];
1120 bool migrate_auto_converge(void)
1124 s
= migrate_get_current();
1126 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_AUTO_CONVERGE
];
1129 bool migrate_zero_blocks(void)
1133 s
= migrate_get_current();
1135 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_ZERO_BLOCKS
];
1138 bool migrate_use_compression(void)
1142 s
= migrate_get_current();
1144 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_COMPRESS
];
1147 int migrate_compress_level(void)
1151 s
= migrate_get_current();
1153 return s
->parameters
[MIGRATION_PARAMETER_COMPRESS_LEVEL
];
1156 int migrate_compress_threads(void)
1160 s
= migrate_get_current();
1162 return s
->parameters
[MIGRATION_PARAMETER_COMPRESS_THREADS
];
1165 int migrate_decompress_threads(void)
1169 s
= migrate_get_current();
1171 return s
->parameters
[MIGRATION_PARAMETER_DECOMPRESS_THREADS
];
1174 bool migrate_use_events(void)
1178 s
= migrate_get_current();
1180 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_EVENTS
];
1183 int migrate_use_xbzrle(void)
1187 s
= migrate_get_current();
1189 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_XBZRLE
];
1192 int64_t migrate_xbzrle_cache_size(void)
1196 s
= migrate_get_current();
1198 return s
->xbzrle_cache_size
;
1201 /* migration thread support */
1203 * Something bad happened to the RP stream, mark an error
1204 * The caller shall print or trace something to indicate why
1206 static void mark_source_rp_bad(MigrationState
*s
)
1208 s
->rp_state
.error
= true;
1211 static struct rp_cmd_args
{
1212 ssize_t len
; /* -1 = variable */
1215 [MIG_RP_MSG_INVALID
] = { .len
= -1, .name
= "INVALID" },
1216 [MIG_RP_MSG_SHUT
] = { .len
= 4, .name
= "SHUT" },
1217 [MIG_RP_MSG_PONG
] = { .len
= 4, .name
= "PONG" },
1218 [MIG_RP_MSG_REQ_PAGES
] = { .len
= 12, .name
= "REQ_PAGES" },
1219 [MIG_RP_MSG_REQ_PAGES_ID
] = { .len
= -1, .name
= "REQ_PAGES_ID" },
1220 [MIG_RP_MSG_MAX
] = { .len
= -1, .name
= "MAX" },
1224 * Process a request for pages received on the return path,
1225 * We're allowed to send more than requested (e.g. to round to our page size)
1226 * and we don't need to send pages that have already been sent.
1228 static void migrate_handle_rp_req_pages(MigrationState
*ms
, const char* rbname
,
1229 ram_addr_t start
, size_t len
)
1231 long our_host_ps
= getpagesize();
1233 trace_migrate_handle_rp_req_pages(rbname
, start
, len
);
1236 * Since we currently insist on matching page sizes, just sanity check
1237 * we're being asked for whole host pages.
1239 if (start
& (our_host_ps
-1) ||
1240 (len
& (our_host_ps
-1))) {
1241 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
1242 " len: %zd", __func__
, start
, len
);
1243 mark_source_rp_bad(ms
);
1247 if (ram_save_queue_pages(ms
, rbname
, start
, len
)) {
1248 mark_source_rp_bad(ms
);
1253 * Handles messages sent on the return path towards the source VM
1256 static void *source_return_path_thread(void *opaque
)
1258 MigrationState
*ms
= opaque
;
1259 QEMUFile
*rp
= ms
->rp_state
.from_dst_file
;
1260 uint16_t header_len
, header_type
;
1261 const int max_len
= 512;
1262 uint8_t buf
[max_len
];
1263 uint32_t tmp32
, sibling_error
;
1264 ram_addr_t start
= 0; /* =0 to silence warning */
1265 size_t len
= 0, expected_len
;
1268 trace_source_return_path_thread_entry();
1269 while (!ms
->rp_state
.error
&& !qemu_file_get_error(rp
) &&
1270 migration_is_setup_or_active(ms
->state
)) {
1271 trace_source_return_path_thread_loop_top();
1272 header_type
= qemu_get_be16(rp
);
1273 header_len
= qemu_get_be16(rp
);
1275 if (header_type
>= MIG_RP_MSG_MAX
||
1276 header_type
== MIG_RP_MSG_INVALID
) {
1277 error_report("RP: Received invalid message 0x%04x length 0x%04x",
1278 header_type
, header_len
);
1279 mark_source_rp_bad(ms
);
1283 if ((rp_cmd_args
[header_type
].len
!= -1 &&
1284 header_len
!= rp_cmd_args
[header_type
].len
) ||
1285 header_len
> max_len
) {
1286 error_report("RP: Received '%s' message (0x%04x) with"
1287 "incorrect length %d expecting %zu",
1288 rp_cmd_args
[header_type
].name
, header_type
, header_len
,
1289 (size_t)rp_cmd_args
[header_type
].len
);
1290 mark_source_rp_bad(ms
);
1294 /* We know we've got a valid header by this point */
1295 res
= qemu_get_buffer(rp
, buf
, header_len
);
1296 if (res
!= header_len
) {
1297 error_report("RP: Failed reading data for message 0x%04x"
1298 " read %d expected %d",
1299 header_type
, res
, header_len
);
1300 mark_source_rp_bad(ms
);
1304 /* OK, we have the message and the data */
1305 switch (header_type
) {
1306 case MIG_RP_MSG_SHUT
:
1307 sibling_error
= be32_to_cpup((uint32_t *)buf
);
1308 trace_source_return_path_thread_shut(sibling_error
);
1309 if (sibling_error
) {
1310 error_report("RP: Sibling indicated error %d", sibling_error
);
1311 mark_source_rp_bad(ms
);
1314 * We'll let the main thread deal with closing the RP
1315 * we could do a shutdown(2) on it, but we're the only user
1316 * anyway, so there's nothing gained.
1320 case MIG_RP_MSG_PONG
:
1321 tmp32
= be32_to_cpup((uint32_t *)buf
);
1322 trace_source_return_path_thread_pong(tmp32
);
1325 case MIG_RP_MSG_REQ_PAGES
:
1326 start
= be64_to_cpup((uint64_t *)buf
);
1327 len
= be32_to_cpup((uint32_t *)(buf
+ 8));
1328 migrate_handle_rp_req_pages(ms
, NULL
, start
, len
);
1331 case MIG_RP_MSG_REQ_PAGES_ID
:
1332 expected_len
= 12 + 1; /* header + termination */
1334 if (header_len
>= expected_len
) {
1335 start
= be64_to_cpup((uint64_t *)buf
);
1336 len
= be32_to_cpup((uint32_t *)(buf
+ 8));
1337 /* Now we expect an idstr */
1338 tmp32
= buf
[12]; /* Length of the following idstr */
1339 buf
[13 + tmp32
] = '\0';
1340 expected_len
+= tmp32
;
1342 if (header_len
!= expected_len
) {
1343 error_report("RP: Req_Page_id with length %d expecting %zd",
1344 header_len
, expected_len
);
1345 mark_source_rp_bad(ms
);
1348 migrate_handle_rp_req_pages(ms
, (char *)&buf
[13], start
, len
);
1355 if (qemu_file_get_error(rp
)) {
1356 trace_source_return_path_thread_bad_end();
1357 mark_source_rp_bad(ms
);
1360 trace_source_return_path_thread_end();
1362 ms
->rp_state
.from_dst_file
= NULL
;
1367 static int open_return_path_on_source(MigrationState
*ms
)
1370 ms
->rp_state
.from_dst_file
= qemu_file_get_return_path(ms
->file
);
1371 if (!ms
->rp_state
.from_dst_file
) {
1375 trace_open_return_path_on_source();
1376 qemu_thread_create(&ms
->rp_state
.rp_thread
, "return path",
1377 source_return_path_thread
, ms
, QEMU_THREAD_JOINABLE
);
1379 trace_open_return_path_on_source_continue();
1384 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1385 static int await_return_path_close_on_source(MigrationState
*ms
)
1388 * If this is a normal exit then the destination will send a SHUT and the
1389 * rp_thread will exit, however if there's an error we need to cause
1392 if (qemu_file_get_error(ms
->file
) && ms
->rp_state
.from_dst_file
) {
1394 * shutdown(2), if we have it, will cause it to unblock if it's stuck
1395 * waiting for the destination.
1397 qemu_file_shutdown(ms
->rp_state
.from_dst_file
);
1398 mark_source_rp_bad(ms
);
1400 trace_await_return_path_close_on_source_joining();
1401 qemu_thread_join(&ms
->rp_state
.rp_thread
);
1402 trace_await_return_path_close_on_source_close();
1403 return ms
->rp_state
.error
;
1407 * Switch from normal iteration to postcopy
1408 * Returns non-0 on error
1410 static int postcopy_start(MigrationState
*ms
, bool *old_vm_running
)
1413 const QEMUSizedBuffer
*qsb
;
1414 int64_t time_at_stop
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1415 migrate_set_state(&ms
->state
, MIGRATION_STATUS_ACTIVE
,
1416 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1418 trace_postcopy_start();
1419 qemu_mutex_lock_iothread();
1420 trace_postcopy_start_set_run();
1422 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
);
1423 *old_vm_running
= runstate_is_running();
1424 global_state_store();
1425 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
1430 ret
= bdrv_inactivate_all();
1436 * Cause any non-postcopiable, but iterative devices to
1437 * send out their final data.
1439 qemu_savevm_state_complete_precopy(ms
->file
, true);
1442 * in Finish migrate and with the io-lock held everything should
1443 * be quiet, but we've potentially still got dirty pages and we
1444 * need to tell the destination to throw any pages it's already received
1447 if (ram_postcopy_send_discard_bitmap(ms
)) {
1448 error_report("postcopy send discard bitmap failed");
1453 * send rest of state - note things that are doing postcopy
1454 * will notice we're in POSTCOPY_ACTIVE and not actually
1455 * wrap their state up here
1457 qemu_file_set_rate_limit(ms
->file
, INT64_MAX
);
1458 /* Ping just for debugging, helps line traces up */
1459 qemu_savevm_send_ping(ms
->file
, 2);
1462 * While loading the device state we may trigger page transfer
1463 * requests and the fd must be free to process those, and thus
1464 * the destination must read the whole device state off the fd before
1465 * it starts processing it. Unfortunately the ad-hoc migration format
1466 * doesn't allow the destination to know the size to read without fully
1467 * parsing it through each devices load-state code (especially the open
1468 * coded devices that use get/put).
1469 * So we wrap the device state up in a package with a length at the start;
1470 * to do this we use a qemu_buf to hold the whole of the device state.
1472 QEMUFile
*fb
= qemu_bufopen("w", NULL
);
1474 error_report("Failed to create buffered file");
1479 * Make sure the receiver can get incoming pages before we send the rest
1482 qemu_savevm_send_postcopy_listen(fb
);
1484 qemu_savevm_state_complete_precopy(fb
, false);
1485 qemu_savevm_send_ping(fb
, 3);
1487 qemu_savevm_send_postcopy_run(fb
);
1489 /* <><> end of stuff going into the package */
1490 qsb
= qemu_buf_get(fb
);
1492 /* Now send that blob */
1493 if (qemu_savevm_send_packaged(ms
->file
, qsb
)) {
1497 ms
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - time_at_stop
;
1499 qemu_mutex_unlock_iothread();
1502 * Although this ping is just for debug, it could potentially be
1503 * used for getting a better measurement of downtime at the source.
1505 qemu_savevm_send_ping(ms
->file
, 4);
1507 ret
= qemu_file_get_error(ms
->file
);
1509 error_report("postcopy_start: Migration stream errored");
1510 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1511 MIGRATION_STATUS_FAILED
);
1519 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1520 MIGRATION_STATUS_FAILED
);
1521 qemu_mutex_unlock_iothread();
1526 * migration_completion: Used by migration_thread when there's not much left.
1527 * The caller 'breaks' the loop when this returns.
1529 * @s: Current migration state
1530 * @current_active_state: The migration state we expect to be in
1531 * @*old_vm_running: Pointer to old_vm_running flag
1532 * @*start_time: Pointer to time to update
1534 static void migration_completion(MigrationState
*s
, int current_active_state
,
1535 bool *old_vm_running
,
1536 int64_t *start_time
)
1540 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
1541 qemu_mutex_lock_iothread();
1542 *start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1543 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
);
1544 *old_vm_running
= runstate_is_running();
1545 ret
= global_state_store();
1548 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
1550 ret
= bdrv_inactivate_all();
1553 qemu_file_set_rate_limit(s
->file
, INT64_MAX
);
1554 qemu_savevm_state_complete_precopy(s
->file
, false);
1557 qemu_mutex_unlock_iothread();
1562 } else if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
1563 trace_migration_completion_postcopy_end();
1565 qemu_savevm_state_complete_postcopy(s
->file
);
1566 trace_migration_completion_postcopy_end_after_complete();
1570 * If rp was opened we must clean up the thread before
1571 * cleaning everything else up (since if there are no failures
1572 * it will wait for the destination to send it's status in
1574 * Postcopy opens rp if enabled (even if it's not avtivated)
1576 if (migrate_postcopy_ram()) {
1578 trace_migration_completion_postcopy_end_before_rp();
1579 rp_error
= await_return_path_close_on_source(s
);
1580 trace_migration_completion_postcopy_end_after_rp(rp_error
);
1586 if (qemu_file_get_error(s
->file
)) {
1587 trace_migration_completion_file_err();
1591 migrate_set_state(&s
->state
, current_active_state
,
1592 MIGRATION_STATUS_COMPLETED
);
1596 migrate_set_state(&s
->state
, current_active_state
,
1597 MIGRATION_STATUS_FAILED
);
1601 * Master migration thread on the source VM.
1602 * It drives the migration and pumps the data down the outgoing channel.
1604 static void *migration_thread(void *opaque
)
1606 MigrationState
*s
= opaque
;
1607 /* Used by the bandwidth calcs, updated later */
1608 int64_t initial_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1609 int64_t setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
1610 int64_t initial_bytes
= 0;
1611 int64_t max_size
= 0;
1612 int64_t start_time
= initial_time
;
1614 bool old_vm_running
= false;
1615 bool entered_postcopy
= false;
1616 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
1617 enum MigrationStatus current_active_state
= MIGRATION_STATUS_ACTIVE
;
1619 rcu_register_thread();
1621 qemu_savevm_state_header(s
->file
);
1623 if (migrate_postcopy_ram()) {
1624 /* Now tell the dest that it should open its end so it can reply */
1625 qemu_savevm_send_open_return_path(s
->file
);
1627 /* And do a ping that will make stuff easier to debug */
1628 qemu_savevm_send_ping(s
->file
, 1);
1631 * Tell the destination that we *might* want to do postcopy later;
1632 * if the other end can't do postcopy it should fail now, nice and
1635 qemu_savevm_send_postcopy_advise(s
->file
);
1638 qemu_savevm_state_begin(s
->file
, &s
->params
);
1640 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
1641 current_active_state
= MIGRATION_STATUS_ACTIVE
;
1642 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1643 MIGRATION_STATUS_ACTIVE
);
1645 trace_migration_thread_setup_complete();
1647 while (s
->state
== MIGRATION_STATUS_ACTIVE
||
1648 s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
1649 int64_t current_time
;
1650 uint64_t pending_size
;
1652 if (!qemu_file_rate_limit(s
->file
)) {
1653 uint64_t pend_post
, pend_nonpost
;
1655 qemu_savevm_state_pending(s
->file
, max_size
, &pend_nonpost
,
1657 pending_size
= pend_nonpost
+ pend_post
;
1658 trace_migrate_pending(pending_size
, max_size
,
1659 pend_post
, pend_nonpost
);
1660 if (pending_size
&& pending_size
>= max_size
) {
1661 /* Still a significant amount to transfer */
1663 if (migrate_postcopy_ram() &&
1664 s
->state
!= MIGRATION_STATUS_POSTCOPY_ACTIVE
&&
1665 pend_nonpost
<= max_size
&&
1666 atomic_read(&s
->start_postcopy
)) {
1668 if (!postcopy_start(s
, &old_vm_running
)) {
1669 current_active_state
= MIGRATION_STATUS_POSTCOPY_ACTIVE
;
1670 entered_postcopy
= true;
1675 /* Just another iteration step */
1676 qemu_savevm_state_iterate(s
->file
, entered_postcopy
);
1678 trace_migration_thread_low_pending(pending_size
);
1679 migration_completion(s
, current_active_state
,
1680 &old_vm_running
, &start_time
);
1685 if (qemu_file_get_error(s
->file
)) {
1686 migrate_set_state(&s
->state
, current_active_state
,
1687 MIGRATION_STATUS_FAILED
);
1688 trace_migration_thread_file_err();
1691 current_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1692 if (current_time
>= initial_time
+ BUFFER_DELAY
) {
1693 uint64_t transferred_bytes
= qemu_ftell(s
->file
) - initial_bytes
;
1694 uint64_t time_spent
= current_time
- initial_time
;
1695 double bandwidth
= (double)transferred_bytes
/ time_spent
;
1696 max_size
= bandwidth
* migrate_max_downtime() / 1000000;
1698 s
->mbps
= time_spent
? (((double) transferred_bytes
* 8.0) /
1699 ((double) time_spent
/ 1000.0)) / 1000.0 / 1000.0 : -1;
1701 trace_migrate_transferred(transferred_bytes
, time_spent
,
1702 bandwidth
, max_size
);
1703 /* if we haven't sent anything, we don't want to recalculate
1704 10000 is a small enough number for our purposes */
1705 if (s
->dirty_bytes_rate
&& transferred_bytes
> 10000) {
1706 s
->expected_downtime
= s
->dirty_bytes_rate
/ bandwidth
;
1709 qemu_file_reset_rate_limit(s
->file
);
1710 initial_time
= current_time
;
1711 initial_bytes
= qemu_ftell(s
->file
);
1713 if (qemu_file_rate_limit(s
->file
)) {
1714 /* usleep expects microseconds */
1715 g_usleep((initial_time
+ BUFFER_DELAY
- current_time
)*1000);
1719 trace_migration_thread_after_loop();
1720 /* If we enabled cpu throttling for auto-converge, turn it off. */
1721 cpu_throttle_stop();
1722 end_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1724 qemu_mutex_lock_iothread();
1725 qemu_savevm_state_cleanup();
1726 if (s
->state
== MIGRATION_STATUS_COMPLETED
) {
1727 uint64_t transferred_bytes
= qemu_ftell(s
->file
);
1728 s
->total_time
= end_time
- s
->total_time
;
1729 if (!entered_postcopy
) {
1730 s
->downtime
= end_time
- start_time
;
1732 if (s
->total_time
) {
1733 s
->mbps
= (((double) transferred_bytes
* 8.0) /
1734 ((double) s
->total_time
)) / 1000;
1736 runstate_set(RUN_STATE_POSTMIGRATE
);
1738 if (old_vm_running
&& !entered_postcopy
) {
1742 qemu_bh_schedule(s
->cleanup_bh
);
1743 qemu_mutex_unlock_iothread();
1745 rcu_unregister_thread();
1749 void migrate_fd_connect(MigrationState
*s
)
1751 /* This is a best 1st approximation. ns to ms */
1752 s
->expected_downtime
= max_downtime
/1000000;
1753 s
->cleanup_bh
= qemu_bh_new(migrate_fd_cleanup
, s
);
1755 qemu_file_set_rate_limit(s
->file
,
1756 s
->bandwidth_limit
/ XFER_LIMIT_RATIO
);
1758 /* Notify before starting migration thread */
1759 notifier_list_notify(&migration_state_notifiers
, s
);
1762 * Open the return path; currently for postcopy but other things might
1765 if (migrate_postcopy_ram()) {
1766 if (open_return_path_on_source(s
)) {
1767 error_report("Unable to open return-path for postcopy");
1768 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1769 MIGRATION_STATUS_FAILED
);
1770 migrate_fd_cleanup(s
);
1775 migrate_compress_threads_create();
1776 qemu_thread_create(&s
->thread
, "migration", migration_thread
, s
,
1777 QEMU_THREAD_JOINABLE
);
1778 s
->migration_thread_running
= true;
1781 PostcopyState
postcopy_state_get(void)
1783 return atomic_mb_read(&incoming_postcopy_state
);
1786 /* Set the state and return the old state */
1787 PostcopyState
postcopy_state_set(PostcopyState new_state
)
1789 return atomic_xchg(&incoming_postcopy_state
, new_state
);