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/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"
37 #include "io/channel-buffer.h"
38 #include "io/channel-tls.h"
39 #include "migration/colo.h"
41 #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
43 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
45 #define BUFFER_DELAY 100
46 #define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
48 /* Time in milliseconds we are allowed to stop the source,
49 * for sending the last part */
50 #define DEFAULT_MIGRATE_SET_DOWNTIME 300
52 /* Default compression thread count */
53 #define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
54 /* Default decompression thread count, usually decompression is at
55 * least 4 times as fast as compression.*/
56 #define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
57 /*0: means nocompress, 1: best speed, ... 9: best compress ratio */
58 #define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
59 /* Define default autoconverge cpu throttle migration parameters */
60 #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20
61 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
63 /* Migration XBZRLE default cache size */
64 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
66 /* The delay time (in ms) between two COLO checkpoints
67 * Note: Please change this default value to 10000 when we support hybrid mode.
69 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200
71 static NotifierList migration_state_notifiers
=
72 NOTIFIER_LIST_INITIALIZER(migration_state_notifiers
);
74 static bool deferred_incoming
;
77 * Current state of incoming postcopy; note this is not part of
78 * MigrationIncomingState since it's state is used during cleanup
79 * at the end as MIS is being freed.
81 static PostcopyState incoming_postcopy_state
;
83 /* When we add fault tolerance, we could have several
84 migrations at once. For now we don't need to add
85 dynamic creation of migration */
88 MigrationState
*migrate_get_current(void)
91 static MigrationState current_migration
= {
92 .state
= MIGRATION_STATUS_NONE
,
93 .xbzrle_cache_size
= DEFAULT_MIGRATE_CACHE_SIZE
,
96 .compress_level
= DEFAULT_MIGRATE_COMPRESS_LEVEL
,
97 .compress_threads
= DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT
,
98 .decompress_threads
= DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT
,
99 .cpu_throttle_initial
= DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL
,
100 .cpu_throttle_increment
= DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT
,
101 .max_bandwidth
= MAX_THROTTLE
,
102 .downtime_limit
= DEFAULT_MIGRATE_SET_DOWNTIME
,
103 .x_checkpoint_delay
= DEFAULT_MIGRATE_X_CHECKPOINT_DELAY
,
108 qemu_mutex_init(¤t_migration
.src_page_req_mutex
);
111 return ¤t_migration
;
115 static MigrationIncomingState
*mis_current
;
117 MigrationIncomingState
*migration_incoming_get_current(void)
122 MigrationIncomingState
*migration_incoming_state_new(QEMUFile
* f
)
124 mis_current
= g_new0(MigrationIncomingState
, 1);
125 mis_current
->from_src_file
= f
;
126 mis_current
->state
= MIGRATION_STATUS_NONE
;
127 QLIST_INIT(&mis_current
->loadvm_handlers
);
128 qemu_mutex_init(&mis_current
->rp_mutex
);
129 qemu_event_init(&mis_current
->main_thread_load_event
, false);
134 void migration_incoming_state_destroy(void)
136 qemu_event_destroy(&mis_current
->main_thread_load_event
);
137 loadvm_free_handlers(mis_current
);
146 uint8_t runstate
[100];
151 static GlobalState global_state
;
153 int global_state_store(void)
155 if (!runstate_store((char *)global_state
.runstate
,
156 sizeof(global_state
.runstate
))) {
157 error_report("runstate name too big: %s", global_state
.runstate
);
158 trace_migrate_state_too_big();
164 void global_state_store_running(void)
166 const char *state
= RunState_lookup
[RUN_STATE_RUNNING
];
167 strncpy((char *)global_state
.runstate
,
168 state
, sizeof(global_state
.runstate
));
171 static bool global_state_received(void)
173 return global_state
.received
;
176 static RunState
global_state_get_runstate(void)
178 return global_state
.state
;
181 void global_state_set_optional(void)
183 global_state
.optional
= true;
186 static bool global_state_needed(void *opaque
)
188 GlobalState
*s
= opaque
;
189 char *runstate
= (char *)s
->runstate
;
191 /* If it is not optional, it is mandatory */
193 if (s
->optional
== false) {
197 /* If state is running or paused, it is not needed */
199 if (strcmp(runstate
, "running") == 0 ||
200 strcmp(runstate
, "paused") == 0) {
204 /* for any other state it is needed */
208 static int global_state_post_load(void *opaque
, int version_id
)
210 GlobalState
*s
= opaque
;
211 Error
*local_err
= NULL
;
213 char *runstate
= (char *)s
->runstate
;
216 trace_migrate_global_state_post_load(runstate
);
218 r
= qapi_enum_parse(RunState_lookup
, runstate
, RUN_STATE__MAX
,
223 error_report_err(local_err
);
232 static void global_state_pre_save(void *opaque
)
234 GlobalState
*s
= opaque
;
236 trace_migrate_global_state_pre_save((char *)s
->runstate
);
237 s
->size
= strlen((char *)s
->runstate
) + 1;
240 static const VMStateDescription vmstate_globalstate
= {
241 .name
= "globalstate",
243 .minimum_version_id
= 1,
244 .post_load
= global_state_post_load
,
245 .pre_save
= global_state_pre_save
,
246 .needed
= global_state_needed
,
247 .fields
= (VMStateField
[]) {
248 VMSTATE_UINT32(size
, GlobalState
),
249 VMSTATE_BUFFER(runstate
, GlobalState
),
250 VMSTATE_END_OF_LIST()
254 void register_global_state(void)
256 /* We would use it independently that we receive it */
257 strcpy((char *)&global_state
.runstate
, "");
258 global_state
.received
= false;
259 vmstate_register(NULL
, 0, &vmstate_globalstate
, &global_state
);
262 static void migrate_generate_event(int new_state
)
264 if (migrate_use_events()) {
265 qapi_event_send_migration(new_state
, &error_abort
);
270 * Called on -incoming with a defer: uri.
271 * The migration can be started later after any parameters have been
274 static void deferred_incoming_migration(Error
**errp
)
276 if (deferred_incoming
) {
277 error_setg(errp
, "Incoming migration already deferred");
279 deferred_incoming
= true;
282 /* Request a range of pages from the source VM at the given
284 * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
285 * as the last request (a name must have been given previously)
286 * Start: Address offset within the RB
287 * Len: Length in bytes required - must be a multiple of pagesize
289 void migrate_send_rp_req_pages(MigrationIncomingState
*mis
, const char *rbname
,
290 ram_addr_t start
, size_t len
)
292 uint8_t bufc
[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
293 size_t msglen
= 12; /* start + len */
295 *(uint64_t *)bufc
= cpu_to_be64((uint64_t)start
);
296 *(uint32_t *)(bufc
+ 8) = cpu_to_be32((uint32_t)len
);
299 int rbname_len
= strlen(rbname
);
300 assert(rbname_len
< 256);
302 bufc
[msglen
++] = rbname_len
;
303 memcpy(bufc
+ msglen
, rbname
, rbname_len
);
304 msglen
+= rbname_len
;
305 migrate_send_rp_message(mis
, MIG_RP_MSG_REQ_PAGES_ID
, msglen
, bufc
);
307 migrate_send_rp_message(mis
, MIG_RP_MSG_REQ_PAGES
, msglen
, bufc
);
311 void qemu_start_incoming_migration(const char *uri
, Error
**errp
)
315 qapi_event_send_migration(MIGRATION_STATUS_SETUP
, &error_abort
);
316 if (!strcmp(uri
, "defer")) {
317 deferred_incoming_migration(errp
);
318 } else if (strstart(uri
, "tcp:", &p
)) {
319 tcp_start_incoming_migration(p
, errp
);
321 } else if (strstart(uri
, "rdma:", &p
)) {
322 rdma_start_incoming_migration(p
, errp
);
324 } else if (strstart(uri
, "exec:", &p
)) {
325 exec_start_incoming_migration(p
, errp
);
326 } else if (strstart(uri
, "unix:", &p
)) {
327 unix_start_incoming_migration(p
, errp
);
328 } else if (strstart(uri
, "fd:", &p
)) {
329 fd_start_incoming_migration(p
, errp
);
331 error_setg(errp
, "unknown migration protocol: %s", uri
);
335 static void process_incoming_migration_bh(void *opaque
)
337 Error
*local_err
= NULL
;
338 MigrationIncomingState
*mis
= opaque
;
340 /* Make sure all file formats flush their mutable metadata */
341 bdrv_invalidate_cache_all(&local_err
);
343 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
344 MIGRATION_STATUS_FAILED
);
345 error_report_err(local_err
);
346 migrate_decompress_threads_join();
351 * This must happen after all error conditions are dealt with and
352 * we're sure the VM is going to be running on this host.
354 qemu_announce_self();
356 /* If global state section was not received or we are in running
357 state, we need to obey autostart. Any other state is set with
360 if (!global_state_received() ||
361 global_state_get_runstate() == RUN_STATE_RUNNING
) {
365 runstate_set(RUN_STATE_PAUSED
);
368 runstate_set(global_state_get_runstate());
370 migrate_decompress_threads_join();
372 * This must happen after any state changes since as soon as an external
373 * observer sees this event they might start to prod at the VM assuming
376 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
377 MIGRATION_STATUS_COMPLETED
);
378 qemu_bh_delete(mis
->bh
);
379 migration_incoming_state_destroy();
382 static void process_incoming_migration_co(void *opaque
)
384 QEMUFile
*f
= opaque
;
385 MigrationIncomingState
*mis
;
389 mis
= migration_incoming_state_new(f
);
390 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
391 migrate_set_state(&mis
->state
, MIGRATION_STATUS_NONE
,
392 MIGRATION_STATUS_ACTIVE
);
393 ret
= qemu_loadvm_state(f
);
395 ps
= postcopy_state_get();
396 trace_process_incoming_migration_co_end(ret
, ps
);
397 if (ps
!= POSTCOPY_INCOMING_NONE
) {
398 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
400 * Where a migration had postcopy enabled (and thus went to advise)
401 * but managed to complete within the precopy period, we can use
404 postcopy_ram_incoming_cleanup(mis
);
405 } else if (ret
>= 0) {
407 * Postcopy was started, cleanup should happen at the end of the
410 trace_process_incoming_migration_co_postcopy_end_main();
413 /* Else if something went wrong then just fall out of the normal exit */
416 /* we get COLO info, and know if we are in COLO mode */
417 if (!ret
&& migration_incoming_enable_colo()) {
418 mis
->migration_incoming_co
= qemu_coroutine_self();
419 qemu_thread_create(&mis
->colo_incoming_thread
, "COLO incoming",
420 colo_process_incoming_thread
, mis
, QEMU_THREAD_JOINABLE
);
421 mis
->have_colo_incoming_thread
= true;
422 qemu_coroutine_yield();
424 /* Wait checkpoint incoming thread exit before free resource */
425 qemu_thread_join(&mis
->colo_incoming_thread
);
429 free_xbzrle_decoded_buf();
432 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
433 MIGRATION_STATUS_FAILED
);
434 error_report("load of migration failed: %s", strerror(-ret
));
435 migrate_decompress_threads_join();
439 mis
->bh
= qemu_bh_new(process_incoming_migration_bh
, mis
);
440 qemu_bh_schedule(mis
->bh
);
443 void migration_fd_process_incoming(QEMUFile
*f
)
445 Coroutine
*co
= qemu_coroutine_create(process_incoming_migration_co
, f
);
447 migrate_decompress_threads_create();
448 qemu_file_set_blocking(f
, false);
449 qemu_coroutine_enter(co
);
453 void migration_channel_process_incoming(MigrationState
*s
,
456 trace_migration_set_incoming_channel(
457 ioc
, object_get_typename(OBJECT(ioc
)));
459 if (s
->parameters
.tls_creds
&&
460 !object_dynamic_cast(OBJECT(ioc
),
461 TYPE_QIO_CHANNEL_TLS
)) {
462 Error
*local_err
= NULL
;
463 migration_tls_channel_process_incoming(s
, ioc
, &local_err
);
465 error_report_err(local_err
);
468 QEMUFile
*f
= qemu_fopen_channel_input(ioc
);
469 migration_fd_process_incoming(f
);
474 void migration_channel_connect(MigrationState
*s
,
476 const char *hostname
)
478 trace_migration_set_outgoing_channel(
479 ioc
, object_get_typename(OBJECT(ioc
)), hostname
);
481 if (s
->parameters
.tls_creds
&&
482 !object_dynamic_cast(OBJECT(ioc
),
483 TYPE_QIO_CHANNEL_TLS
)) {
484 Error
*local_err
= NULL
;
485 migration_tls_channel_connect(s
, ioc
, hostname
, &local_err
);
487 migrate_fd_error(s
, local_err
);
488 error_free(local_err
);
491 QEMUFile
*f
= qemu_fopen_channel_output(ioc
);
495 migrate_fd_connect(s
);
501 * Send a message on the return channel back to the source
504 void migrate_send_rp_message(MigrationIncomingState
*mis
,
505 enum mig_rp_message_type message_type
,
506 uint16_t len
, void *data
)
508 trace_migrate_send_rp_message((int)message_type
, len
);
509 qemu_mutex_lock(&mis
->rp_mutex
);
510 qemu_put_be16(mis
->to_src_file
, (unsigned int)message_type
);
511 qemu_put_be16(mis
->to_src_file
, len
);
512 qemu_put_buffer(mis
->to_src_file
, data
, len
);
513 qemu_fflush(mis
->to_src_file
);
514 qemu_mutex_unlock(&mis
->rp_mutex
);
518 * Send a 'SHUT' message on the return channel with the given value
519 * to indicate that we've finished with the RP. Non-0 value indicates
522 void migrate_send_rp_shut(MigrationIncomingState
*mis
,
527 buf
= cpu_to_be32(value
);
528 migrate_send_rp_message(mis
, MIG_RP_MSG_SHUT
, sizeof(buf
), &buf
);
532 * Send a 'PONG' message on the return channel with the given value
533 * (normally in response to a 'PING')
535 void migrate_send_rp_pong(MigrationIncomingState
*mis
,
540 buf
= cpu_to_be32(value
);
541 migrate_send_rp_message(mis
, MIG_RP_MSG_PONG
, sizeof(buf
), &buf
);
544 MigrationCapabilityStatusList
*qmp_query_migrate_capabilities(Error
**errp
)
546 MigrationCapabilityStatusList
*head
= NULL
;
547 MigrationCapabilityStatusList
*caps
;
548 MigrationState
*s
= migrate_get_current();
551 caps
= NULL
; /* silence compiler warning */
552 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
553 if (i
== MIGRATION_CAPABILITY_X_COLO
&& !colo_supported()) {
557 head
= g_malloc0(sizeof(*caps
));
560 caps
->next
= g_malloc0(sizeof(*caps
));
564 g_malloc(sizeof(*caps
->value
));
565 caps
->value
->capability
= i
;
566 caps
->value
->state
= s
->enabled_capabilities
[i
];
572 MigrationParameters
*qmp_query_migrate_parameters(Error
**errp
)
574 MigrationParameters
*params
;
575 MigrationState
*s
= migrate_get_current();
577 params
= g_malloc0(sizeof(*params
));
578 params
->has_compress_level
= true;
579 params
->compress_level
= s
->parameters
.compress_level
;
580 params
->has_compress_threads
= true;
581 params
->compress_threads
= s
->parameters
.compress_threads
;
582 params
->has_decompress_threads
= true;
583 params
->decompress_threads
= s
->parameters
.decompress_threads
;
584 params
->has_cpu_throttle_initial
= true;
585 params
->cpu_throttle_initial
= s
->parameters
.cpu_throttle_initial
;
586 params
->has_cpu_throttle_increment
= true;
587 params
->cpu_throttle_increment
= s
->parameters
.cpu_throttle_increment
;
588 params
->has_tls_creds
= !!s
->parameters
.tls_creds
;
589 params
->tls_creds
= g_strdup(s
->parameters
.tls_creds
);
590 params
->has_tls_hostname
= !!s
->parameters
.tls_hostname
;
591 params
->tls_hostname
= g_strdup(s
->parameters
.tls_hostname
);
592 params
->has_max_bandwidth
= true;
593 params
->max_bandwidth
= s
->parameters
.max_bandwidth
;
594 params
->has_downtime_limit
= true;
595 params
->downtime_limit
= s
->parameters
.downtime_limit
;
596 params
->x_checkpoint_delay
= s
->parameters
.x_checkpoint_delay
;
602 * Return true if we're already in the middle of a migration
603 * (i.e. any of the active or setup states)
605 static bool migration_is_setup_or_active(int state
)
608 case MIGRATION_STATUS_ACTIVE
:
609 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
610 case MIGRATION_STATUS_SETUP
:
619 static void get_xbzrle_cache_stats(MigrationInfo
*info
)
621 if (migrate_use_xbzrle()) {
622 info
->has_xbzrle_cache
= true;
623 info
->xbzrle_cache
= g_malloc0(sizeof(*info
->xbzrle_cache
));
624 info
->xbzrle_cache
->cache_size
= migrate_xbzrle_cache_size();
625 info
->xbzrle_cache
->bytes
= xbzrle_mig_bytes_transferred();
626 info
->xbzrle_cache
->pages
= xbzrle_mig_pages_transferred();
627 info
->xbzrle_cache
->cache_miss
= xbzrle_mig_pages_cache_miss();
628 info
->xbzrle_cache
->cache_miss_rate
= xbzrle_mig_cache_miss_rate();
629 info
->xbzrle_cache
->overflow
= xbzrle_mig_pages_overflow();
633 static void populate_ram_info(MigrationInfo
*info
, MigrationState
*s
)
635 info
->has_ram
= true;
636 info
->ram
= g_malloc0(sizeof(*info
->ram
));
637 info
->ram
->transferred
= ram_bytes_transferred();
638 info
->ram
->total
= ram_bytes_total();
639 info
->ram
->duplicate
= dup_mig_pages_transferred();
640 info
->ram
->skipped
= skipped_mig_pages_transferred();
641 info
->ram
->normal
= norm_mig_pages_transferred();
642 info
->ram
->normal_bytes
= norm_mig_bytes_transferred();
643 info
->ram
->mbps
= s
->mbps
;
644 info
->ram
->dirty_sync_count
= s
->dirty_sync_count
;
645 info
->ram
->postcopy_requests
= s
->postcopy_requests
;
647 if (s
->state
!= MIGRATION_STATUS_COMPLETED
) {
648 info
->ram
->remaining
= ram_bytes_remaining();
649 info
->ram
->dirty_pages_rate
= s
->dirty_pages_rate
;
653 MigrationInfo
*qmp_query_migrate(Error
**errp
)
655 MigrationInfo
*info
= g_malloc0(sizeof(*info
));
656 MigrationState
*s
= migrate_get_current();
659 case MIGRATION_STATUS_NONE
:
660 /* no migration has happened ever */
662 case MIGRATION_STATUS_SETUP
:
663 info
->has_status
= true;
664 info
->has_total_time
= false;
666 case MIGRATION_STATUS_ACTIVE
:
667 case MIGRATION_STATUS_CANCELLING
:
668 info
->has_status
= true;
669 info
->has_total_time
= true;
670 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
)
672 info
->has_expected_downtime
= true;
673 info
->expected_downtime
= s
->expected_downtime
;
674 info
->has_setup_time
= true;
675 info
->setup_time
= s
->setup_time
;
677 populate_ram_info(info
, s
);
679 if (blk_mig_active()) {
680 info
->has_disk
= true;
681 info
->disk
= g_malloc0(sizeof(*info
->disk
));
682 info
->disk
->transferred
= blk_mig_bytes_transferred();
683 info
->disk
->remaining
= blk_mig_bytes_remaining();
684 info
->disk
->total
= blk_mig_bytes_total();
687 if (cpu_throttle_active()) {
688 info
->has_cpu_throttle_percentage
= true;
689 info
->cpu_throttle_percentage
= cpu_throttle_get_percentage();
692 get_xbzrle_cache_stats(info
);
694 case MIGRATION_STATUS_POSTCOPY_ACTIVE
:
695 /* Mostly the same as active; TODO add some postcopy stats */
696 info
->has_status
= true;
697 info
->has_total_time
= true;
698 info
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
)
700 info
->has_expected_downtime
= true;
701 info
->expected_downtime
= s
->expected_downtime
;
702 info
->has_setup_time
= true;
703 info
->setup_time
= s
->setup_time
;
705 populate_ram_info(info
, s
);
707 if (blk_mig_active()) {
708 info
->has_disk
= true;
709 info
->disk
= g_malloc0(sizeof(*info
->disk
));
710 info
->disk
->transferred
= blk_mig_bytes_transferred();
711 info
->disk
->remaining
= blk_mig_bytes_remaining();
712 info
->disk
->total
= blk_mig_bytes_total();
715 get_xbzrle_cache_stats(info
);
717 case MIGRATION_STATUS_COLO
:
718 info
->has_status
= true;
719 /* TODO: display COLO specific information (checkpoint info etc.) */
721 case MIGRATION_STATUS_COMPLETED
:
722 get_xbzrle_cache_stats(info
);
724 info
->has_status
= true;
725 info
->has_total_time
= true;
726 info
->total_time
= s
->total_time
;
727 info
->has_downtime
= true;
728 info
->downtime
= s
->downtime
;
729 info
->has_setup_time
= true;
730 info
->setup_time
= s
->setup_time
;
732 populate_ram_info(info
, s
);
734 case MIGRATION_STATUS_FAILED
:
735 info
->has_status
= true;
737 info
->has_error_desc
= true;
738 info
->error_desc
= g_strdup(error_get_pretty(s
->error
));
741 case MIGRATION_STATUS_CANCELLED
:
742 info
->has_status
= true;
745 info
->status
= s
->state
;
750 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList
*params
,
753 MigrationState
*s
= migrate_get_current();
754 MigrationCapabilityStatusList
*cap
;
755 bool old_postcopy_cap
= migrate_postcopy_ram();
757 if (migration_is_setup_or_active(s
->state
)) {
758 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
762 for (cap
= params
; cap
; cap
= cap
->next
) {
763 if (cap
->value
->capability
== MIGRATION_CAPABILITY_X_COLO
) {
764 if (!colo_supported()) {
765 error_setg(errp
, "COLO is not currently supported, please"
766 " configure with --enable-colo option in order to"
767 " support COLO feature");
771 s
->enabled_capabilities
[cap
->value
->capability
] = cap
->value
->state
;
774 if (migrate_postcopy_ram()) {
775 if (migrate_use_compression()) {
776 /* The decompression threads asynchronously write into RAM
777 * rather than use the atomic copies needed to avoid
778 * userfaulting. It should be possible to fix the decompression
779 * threads for compatibility in future.
781 error_report("Postcopy is not currently compatible with "
783 s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_RAM
] =
786 /* This check is reasonably expensive, so only when it's being
787 * set the first time, also it's only the destination that needs
790 if (!old_postcopy_cap
&& runstate_check(RUN_STATE_INMIGRATE
) &&
791 !postcopy_ram_supported_by_host()) {
792 /* postcopy_ram_supported_by_host will have emitted a more
795 error_report("Postcopy is not supported");
796 s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_RAM
] =
802 void qmp_migrate_set_parameters(MigrationParameters
*params
, Error
**errp
)
804 MigrationState
*s
= migrate_get_current();
806 if (params
->has_compress_level
&&
807 (params
->compress_level
< 0 || params
->compress_level
> 9)) {
808 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "compress_level",
809 "is invalid, it should be in the range of 0 to 9");
812 if (params
->has_compress_threads
&&
813 (params
->compress_threads
< 1 || params
->compress_threads
> 255)) {
814 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
816 "is invalid, it should be in the range of 1 to 255");
819 if (params
->has_decompress_threads
&&
820 (params
->decompress_threads
< 1 || params
->decompress_threads
> 255)) {
821 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
822 "decompress_threads",
823 "is invalid, it should be in the range of 1 to 255");
826 if (params
->has_cpu_throttle_initial
&&
827 (params
->cpu_throttle_initial
< 1 ||
828 params
->cpu_throttle_initial
> 99)) {
829 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
830 "cpu_throttle_initial",
831 "an integer in the range of 1 to 99");
834 if (params
->has_cpu_throttle_increment
&&
835 (params
->cpu_throttle_increment
< 1 ||
836 params
->cpu_throttle_increment
> 99)) {
837 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
838 "cpu_throttle_increment",
839 "an integer in the range of 1 to 99");
842 if (params
->has_max_bandwidth
&&
843 (params
->max_bandwidth
< 0 || params
->max_bandwidth
> SIZE_MAX
)) {
844 error_setg(errp
, "Parameter 'max_bandwidth' expects an integer in the"
845 " range of 0 to %zu bytes/second", SIZE_MAX
);
848 if (params
->has_downtime_limit
&&
849 (params
->downtime_limit
< 0 || params
->downtime_limit
> 2000000)) {
850 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
852 "an integer in the range of 0 to 2000000 milliseconds");
855 if (params
->has_x_checkpoint_delay
&& (params
->x_checkpoint_delay
< 0)) {
856 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
,
857 "x_checkpoint_delay",
858 "is invalid, it should be positive");
861 if (params
->has_compress_level
) {
862 s
->parameters
.compress_level
= params
->compress_level
;
864 if (params
->has_compress_threads
) {
865 s
->parameters
.compress_threads
= params
->compress_threads
;
867 if (params
->has_decompress_threads
) {
868 s
->parameters
.decompress_threads
= params
->decompress_threads
;
870 if (params
->has_cpu_throttle_initial
) {
871 s
->parameters
.cpu_throttle_initial
= params
->cpu_throttle_initial
;
873 if (params
->has_cpu_throttle_increment
) {
874 s
->parameters
.cpu_throttle_increment
= params
->cpu_throttle_increment
;
876 if (params
->has_tls_creds
) {
877 g_free(s
->parameters
.tls_creds
);
878 s
->parameters
.tls_creds
= g_strdup(params
->tls_creds
);
880 if (params
->has_tls_hostname
) {
881 g_free(s
->parameters
.tls_hostname
);
882 s
->parameters
.tls_hostname
= g_strdup(params
->tls_hostname
);
884 if (params
->has_max_bandwidth
) {
885 s
->parameters
.max_bandwidth
= params
->max_bandwidth
;
886 if (s
->to_dst_file
) {
887 qemu_file_set_rate_limit(s
->to_dst_file
,
888 s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
);
891 if (params
->has_downtime_limit
) {
892 s
->parameters
.downtime_limit
= params
->downtime_limit
;
895 if (params
->has_x_checkpoint_delay
) {
896 s
->parameters
.x_checkpoint_delay
= params
->x_checkpoint_delay
;
901 void qmp_migrate_start_postcopy(Error
**errp
)
903 MigrationState
*s
= migrate_get_current();
905 if (!migrate_postcopy_ram()) {
906 error_setg(errp
, "Enable postcopy with migrate_set_capability before"
907 " the start of migration");
911 if (s
->state
== MIGRATION_STATUS_NONE
) {
912 error_setg(errp
, "Postcopy must be started after migration has been"
917 * we don't error if migration has finished since that would be racy
918 * with issuing this command.
920 atomic_set(&s
->start_postcopy
, true);
923 /* shared migration helpers */
925 void migrate_set_state(int *state
, int old_state
, int new_state
)
927 if (atomic_cmpxchg(state
, old_state
, new_state
) == old_state
) {
928 trace_migrate_set_state(new_state
);
929 migrate_generate_event(new_state
);
933 static void migrate_fd_cleanup(void *opaque
)
935 MigrationState
*s
= opaque
;
937 qemu_bh_delete(s
->cleanup_bh
);
938 s
->cleanup_bh
= NULL
;
942 if (s
->to_dst_file
) {
943 trace_migrate_fd_cleanup();
944 qemu_mutex_unlock_iothread();
945 if (s
->migration_thread_running
) {
946 qemu_thread_join(&s
->thread
);
947 s
->migration_thread_running
= false;
949 qemu_mutex_lock_iothread();
951 migrate_compress_threads_join();
952 qemu_fclose(s
->to_dst_file
);
953 s
->to_dst_file
= NULL
;
956 assert((s
->state
!= MIGRATION_STATUS_ACTIVE
) &&
957 (s
->state
!= MIGRATION_STATUS_POSTCOPY_ACTIVE
));
959 if (s
->state
== MIGRATION_STATUS_CANCELLING
) {
960 migrate_set_state(&s
->state
, MIGRATION_STATUS_CANCELLING
,
961 MIGRATION_STATUS_CANCELLED
);
964 notifier_list_notify(&migration_state_notifiers
, s
);
967 void migrate_fd_error(MigrationState
*s
, const Error
*error
)
969 trace_migrate_fd_error(error_get_pretty(error
));
970 assert(s
->to_dst_file
== NULL
);
971 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
972 MIGRATION_STATUS_FAILED
);
974 s
->error
= error_copy(error
);
976 notifier_list_notify(&migration_state_notifiers
, s
);
979 static void migrate_fd_cancel(MigrationState
*s
)
982 QEMUFile
*f
= migrate_get_current()->to_dst_file
;
983 trace_migrate_fd_cancel();
985 if (s
->rp_state
.from_dst_file
) {
986 /* shutdown the rp socket, so causing the rp thread to shutdown */
987 qemu_file_shutdown(s
->rp_state
.from_dst_file
);
991 old_state
= s
->state
;
992 if (!migration_is_setup_or_active(old_state
)) {
995 migrate_set_state(&s
->state
, old_state
, MIGRATION_STATUS_CANCELLING
);
996 } while (s
->state
!= MIGRATION_STATUS_CANCELLING
);
999 * If we're unlucky the migration code might be stuck somewhere in a
1000 * send/write while the network has failed and is waiting to timeout;
1001 * if we've got shutdown(2) available then we can force it to quit.
1002 * The outgoing qemu file gets closed in migrate_fd_cleanup that is
1003 * called in a bh, so there is no race against this cancel.
1005 if (s
->state
== MIGRATION_STATUS_CANCELLING
&& f
) {
1006 qemu_file_shutdown(f
);
1010 void add_migration_state_change_notifier(Notifier
*notify
)
1012 notifier_list_add(&migration_state_notifiers
, notify
);
1015 void remove_migration_state_change_notifier(Notifier
*notify
)
1017 notifier_remove(notify
);
1020 bool migration_in_setup(MigrationState
*s
)
1022 return s
->state
== MIGRATION_STATUS_SETUP
;
1025 bool migration_has_finished(MigrationState
*s
)
1027 return s
->state
== MIGRATION_STATUS_COMPLETED
;
1030 bool migration_has_failed(MigrationState
*s
)
1032 return (s
->state
== MIGRATION_STATUS_CANCELLED
||
1033 s
->state
== MIGRATION_STATUS_FAILED
);
1036 bool migration_in_postcopy(MigrationState
*s
)
1038 return (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1041 bool migration_in_postcopy_after_devices(MigrationState
*s
)
1043 return migration_in_postcopy(s
) && s
->postcopy_after_devices
;
1046 MigrationState
*migrate_init(const MigrationParams
*params
)
1048 MigrationState
*s
= migrate_get_current();
1051 * Reinitialise all migration state, except
1052 * parameters/capabilities that the user set, and
1058 s
->to_dst_file
= NULL
;
1059 s
->state
= MIGRATION_STATUS_NONE
;
1060 s
->params
= *params
;
1061 s
->rp_state
.from_dst_file
= NULL
;
1062 s
->rp_state
.error
= false;
1065 s
->expected_downtime
= 0;
1066 s
->dirty_pages_rate
= 0;
1067 s
->dirty_bytes_rate
= 0;
1069 s
->dirty_sync_count
= 0;
1070 s
->start_postcopy
= false;
1071 s
->postcopy_after_devices
= false;
1072 s
->postcopy_requests
= 0;
1073 s
->migration_thread_running
= false;
1074 s
->last_req_rb
= NULL
;
1075 error_free(s
->error
);
1078 migrate_set_state(&s
->state
, MIGRATION_STATUS_NONE
, MIGRATION_STATUS_SETUP
);
1080 QSIMPLEQ_INIT(&s
->src_page_requests
);
1082 s
->total_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1086 static GSList
*migration_blockers
;
1088 void migrate_add_blocker(Error
*reason
)
1090 migration_blockers
= g_slist_prepend(migration_blockers
, reason
);
1093 void migrate_del_blocker(Error
*reason
)
1095 migration_blockers
= g_slist_remove(migration_blockers
, reason
);
1098 void qmp_migrate_incoming(const char *uri
, Error
**errp
)
1100 Error
*local_err
= NULL
;
1101 static bool once
= true;
1103 if (!deferred_incoming
) {
1104 error_setg(errp
, "For use with '-incoming defer'");
1108 error_setg(errp
, "The incoming migration has already been started");
1111 qemu_start_incoming_migration(uri
, &local_err
);
1114 error_propagate(errp
, local_err
);
1121 bool migration_is_blocked(Error
**errp
)
1123 if (qemu_savevm_state_blocked(errp
)) {
1127 if (migration_blockers
) {
1128 *errp
= error_copy(migration_blockers
->data
);
1135 void qmp_migrate(const char *uri
, bool has_blk
, bool blk
,
1136 bool has_inc
, bool inc
, bool has_detach
, bool detach
,
1139 Error
*local_err
= NULL
;
1140 MigrationState
*s
= migrate_get_current();
1141 MigrationParams params
;
1144 params
.blk
= has_blk
&& blk
;
1145 params
.shared
= has_inc
&& inc
;
1147 if (migration_is_setup_or_active(s
->state
) ||
1148 s
->state
== MIGRATION_STATUS_CANCELLING
||
1149 s
->state
== MIGRATION_STATUS_COLO
) {
1150 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
1153 if (runstate_check(RUN_STATE_INMIGRATE
)) {
1154 error_setg(errp
, "Guest is waiting for an incoming migration");
1158 if (migration_is_blocked(errp
)) {
1162 s
= migrate_init(¶ms
);
1164 if (strstart(uri
, "tcp:", &p
)) {
1165 tcp_start_outgoing_migration(s
, p
, &local_err
);
1167 } else if (strstart(uri
, "rdma:", &p
)) {
1168 rdma_start_outgoing_migration(s
, p
, &local_err
);
1170 } else if (strstart(uri
, "exec:", &p
)) {
1171 exec_start_outgoing_migration(s
, p
, &local_err
);
1172 } else if (strstart(uri
, "unix:", &p
)) {
1173 unix_start_outgoing_migration(s
, p
, &local_err
);
1174 } else if (strstart(uri
, "fd:", &p
)) {
1175 fd_start_outgoing_migration(s
, p
, &local_err
);
1177 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "uri",
1178 "a valid migration protocol");
1179 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1180 MIGRATION_STATUS_FAILED
);
1185 migrate_fd_error(s
, local_err
);
1186 error_propagate(errp
, local_err
);
1191 void qmp_migrate_cancel(Error
**errp
)
1193 migrate_fd_cancel(migrate_get_current());
1196 void qmp_migrate_set_cache_size(int64_t value
, Error
**errp
)
1198 MigrationState
*s
= migrate_get_current();
1201 /* Check for truncation */
1202 if (value
!= (size_t)value
) {
1203 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "cache size",
1204 "exceeding address space");
1208 /* Cache should not be larger than guest ram size */
1209 if (value
> ram_bytes_total()) {
1210 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "cache size",
1211 "exceeds guest ram size ");
1215 new_size
= xbzrle_cache_resize(value
);
1217 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "cache size",
1218 "is smaller than page size");
1222 s
->xbzrle_cache_size
= new_size
;
1225 int64_t qmp_query_migrate_cache_size(Error
**errp
)
1227 return migrate_xbzrle_cache_size();
1230 void qmp_migrate_set_speed(int64_t value
, Error
**errp
)
1232 MigrationParameters p
= {
1233 .has_max_bandwidth
= true,
1234 .max_bandwidth
= value
,
1237 qmp_migrate_set_parameters(&p
, errp
);
1240 void qmp_migrate_set_downtime(double value
, Error
**errp
)
1242 value
*= 1000; /* Convert to milliseconds */
1243 value
= MAX(0, MIN(INT64_MAX
, value
));
1245 MigrationParameters p
= {
1246 .has_downtime_limit
= true,
1247 .downtime_limit
= value
,
1250 qmp_migrate_set_parameters(&p
, errp
);
1253 bool migrate_postcopy_ram(void)
1257 s
= migrate_get_current();
1259 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_POSTCOPY_RAM
];
1262 bool migrate_auto_converge(void)
1266 s
= migrate_get_current();
1268 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_AUTO_CONVERGE
];
1271 bool migrate_zero_blocks(void)
1275 s
= migrate_get_current();
1277 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_ZERO_BLOCKS
];
1280 bool migrate_use_compression(void)
1284 s
= migrate_get_current();
1286 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_COMPRESS
];
1289 int migrate_compress_level(void)
1293 s
= migrate_get_current();
1295 return s
->parameters
.compress_level
;
1298 int migrate_compress_threads(void)
1302 s
= migrate_get_current();
1304 return s
->parameters
.compress_threads
;
1307 int migrate_decompress_threads(void)
1311 s
= migrate_get_current();
1313 return s
->parameters
.decompress_threads
;
1316 bool migrate_use_events(void)
1320 s
= migrate_get_current();
1322 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_EVENTS
];
1325 int migrate_use_xbzrle(void)
1329 s
= migrate_get_current();
1331 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_XBZRLE
];
1334 int64_t migrate_xbzrle_cache_size(void)
1338 s
= migrate_get_current();
1340 return s
->xbzrle_cache_size
;
1343 /* migration thread support */
1345 * Something bad happened to the RP stream, mark an error
1346 * The caller shall print or trace something to indicate why
1348 static void mark_source_rp_bad(MigrationState
*s
)
1350 s
->rp_state
.error
= true;
1353 static struct rp_cmd_args
{
1354 ssize_t len
; /* -1 = variable */
1357 [MIG_RP_MSG_INVALID
] = { .len
= -1, .name
= "INVALID" },
1358 [MIG_RP_MSG_SHUT
] = { .len
= 4, .name
= "SHUT" },
1359 [MIG_RP_MSG_PONG
] = { .len
= 4, .name
= "PONG" },
1360 [MIG_RP_MSG_REQ_PAGES
] = { .len
= 12, .name
= "REQ_PAGES" },
1361 [MIG_RP_MSG_REQ_PAGES_ID
] = { .len
= -1, .name
= "REQ_PAGES_ID" },
1362 [MIG_RP_MSG_MAX
] = { .len
= -1, .name
= "MAX" },
1366 * Process a request for pages received on the return path,
1367 * We're allowed to send more than requested (e.g. to round to our page size)
1368 * and we don't need to send pages that have already been sent.
1370 static void migrate_handle_rp_req_pages(MigrationState
*ms
, const char* rbname
,
1371 ram_addr_t start
, size_t len
)
1373 long our_host_ps
= getpagesize();
1375 trace_migrate_handle_rp_req_pages(rbname
, start
, len
);
1378 * Since we currently insist on matching page sizes, just sanity check
1379 * we're being asked for whole host pages.
1381 if (start
& (our_host_ps
-1) ||
1382 (len
& (our_host_ps
-1))) {
1383 error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
1384 " len: %zd", __func__
, start
, len
);
1385 mark_source_rp_bad(ms
);
1389 if (ram_save_queue_pages(ms
, rbname
, start
, len
)) {
1390 mark_source_rp_bad(ms
);
1395 * Handles messages sent on the return path towards the source VM
1398 static void *source_return_path_thread(void *opaque
)
1400 MigrationState
*ms
= opaque
;
1401 QEMUFile
*rp
= ms
->rp_state
.from_dst_file
;
1402 uint16_t header_len
, header_type
;
1404 uint32_t tmp32
, sibling_error
;
1405 ram_addr_t start
= 0; /* =0 to silence warning */
1406 size_t len
= 0, expected_len
;
1409 trace_source_return_path_thread_entry();
1410 while (!ms
->rp_state
.error
&& !qemu_file_get_error(rp
) &&
1411 migration_is_setup_or_active(ms
->state
)) {
1412 trace_source_return_path_thread_loop_top();
1413 header_type
= qemu_get_be16(rp
);
1414 header_len
= qemu_get_be16(rp
);
1416 if (header_type
>= MIG_RP_MSG_MAX
||
1417 header_type
== MIG_RP_MSG_INVALID
) {
1418 error_report("RP: Received invalid message 0x%04x length 0x%04x",
1419 header_type
, header_len
);
1420 mark_source_rp_bad(ms
);
1424 if ((rp_cmd_args
[header_type
].len
!= -1 &&
1425 header_len
!= rp_cmd_args
[header_type
].len
) ||
1426 header_len
> sizeof(buf
)) {
1427 error_report("RP: Received '%s' message (0x%04x) with"
1428 "incorrect length %d expecting %zu",
1429 rp_cmd_args
[header_type
].name
, header_type
, header_len
,
1430 (size_t)rp_cmd_args
[header_type
].len
);
1431 mark_source_rp_bad(ms
);
1435 /* We know we've got a valid header by this point */
1436 res
= qemu_get_buffer(rp
, buf
, header_len
);
1437 if (res
!= header_len
) {
1438 error_report("RP: Failed reading data for message 0x%04x"
1439 " read %d expected %d",
1440 header_type
, res
, header_len
);
1441 mark_source_rp_bad(ms
);
1445 /* OK, we have the message and the data */
1446 switch (header_type
) {
1447 case MIG_RP_MSG_SHUT
:
1448 sibling_error
= ldl_be_p(buf
);
1449 trace_source_return_path_thread_shut(sibling_error
);
1450 if (sibling_error
) {
1451 error_report("RP: Sibling indicated error %d", sibling_error
);
1452 mark_source_rp_bad(ms
);
1455 * We'll let the main thread deal with closing the RP
1456 * we could do a shutdown(2) on it, but we're the only user
1457 * anyway, so there's nothing gained.
1461 case MIG_RP_MSG_PONG
:
1462 tmp32
= ldl_be_p(buf
);
1463 trace_source_return_path_thread_pong(tmp32
);
1466 case MIG_RP_MSG_REQ_PAGES
:
1467 start
= ldq_be_p(buf
);
1468 len
= ldl_be_p(buf
+ 8);
1469 migrate_handle_rp_req_pages(ms
, NULL
, start
, len
);
1472 case MIG_RP_MSG_REQ_PAGES_ID
:
1473 expected_len
= 12 + 1; /* header + termination */
1475 if (header_len
>= expected_len
) {
1476 start
= ldq_be_p(buf
);
1477 len
= ldl_be_p(buf
+ 8);
1478 /* Now we expect an idstr */
1479 tmp32
= buf
[12]; /* Length of the following idstr */
1480 buf
[13 + tmp32
] = '\0';
1481 expected_len
+= tmp32
;
1483 if (header_len
!= expected_len
) {
1484 error_report("RP: Req_Page_id with length %d expecting %zd",
1485 header_len
, expected_len
);
1486 mark_source_rp_bad(ms
);
1489 migrate_handle_rp_req_pages(ms
, (char *)&buf
[13], start
, len
);
1496 if (qemu_file_get_error(rp
)) {
1497 trace_source_return_path_thread_bad_end();
1498 mark_source_rp_bad(ms
);
1501 trace_source_return_path_thread_end();
1503 ms
->rp_state
.from_dst_file
= NULL
;
1508 static int open_return_path_on_source(MigrationState
*ms
)
1511 ms
->rp_state
.from_dst_file
= qemu_file_get_return_path(ms
->to_dst_file
);
1512 if (!ms
->rp_state
.from_dst_file
) {
1516 trace_open_return_path_on_source();
1517 qemu_thread_create(&ms
->rp_state
.rp_thread
, "return path",
1518 source_return_path_thread
, ms
, QEMU_THREAD_JOINABLE
);
1520 trace_open_return_path_on_source_continue();
1525 /* Returns 0 if the RP was ok, otherwise there was an error on the RP */
1526 static int await_return_path_close_on_source(MigrationState
*ms
)
1529 * If this is a normal exit then the destination will send a SHUT and the
1530 * rp_thread will exit, however if there's an error we need to cause
1533 if (qemu_file_get_error(ms
->to_dst_file
) && ms
->rp_state
.from_dst_file
) {
1535 * shutdown(2), if we have it, will cause it to unblock if it's stuck
1536 * waiting for the destination.
1538 qemu_file_shutdown(ms
->rp_state
.from_dst_file
);
1539 mark_source_rp_bad(ms
);
1541 trace_await_return_path_close_on_source_joining();
1542 qemu_thread_join(&ms
->rp_state
.rp_thread
);
1543 trace_await_return_path_close_on_source_close();
1544 return ms
->rp_state
.error
;
1548 * Switch from normal iteration to postcopy
1549 * Returns non-0 on error
1551 static int postcopy_start(MigrationState
*ms
, bool *old_vm_running
)
1554 QIOChannelBuffer
*bioc
;
1556 int64_t time_at_stop
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1557 migrate_set_state(&ms
->state
, MIGRATION_STATUS_ACTIVE
,
1558 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1560 trace_postcopy_start();
1561 qemu_mutex_lock_iothread();
1562 trace_postcopy_start_set_run();
1564 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
);
1565 *old_vm_running
= runstate_is_running();
1566 global_state_store();
1567 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
1572 ret
= bdrv_inactivate_all();
1578 * Cause any non-postcopiable, but iterative devices to
1579 * send out their final data.
1581 qemu_savevm_state_complete_precopy(ms
->to_dst_file
, true);
1584 * in Finish migrate and with the io-lock held everything should
1585 * be quiet, but we've potentially still got dirty pages and we
1586 * need to tell the destination to throw any pages it's already received
1589 if (ram_postcopy_send_discard_bitmap(ms
)) {
1590 error_report("postcopy send discard bitmap failed");
1595 * send rest of state - note things that are doing postcopy
1596 * will notice we're in POSTCOPY_ACTIVE and not actually
1597 * wrap their state up here
1599 qemu_file_set_rate_limit(ms
->to_dst_file
, INT64_MAX
);
1600 /* Ping just for debugging, helps line traces up */
1601 qemu_savevm_send_ping(ms
->to_dst_file
, 2);
1604 * While loading the device state we may trigger page transfer
1605 * requests and the fd must be free to process those, and thus
1606 * the destination must read the whole device state off the fd before
1607 * it starts processing it. Unfortunately the ad-hoc migration format
1608 * doesn't allow the destination to know the size to read without fully
1609 * parsing it through each devices load-state code (especially the open
1610 * coded devices that use get/put).
1611 * So we wrap the device state up in a package with a length at the start;
1612 * to do this we use a qemu_buf to hold the whole of the device state.
1614 bioc
= qio_channel_buffer_new(4096);
1615 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-postcopy-buffer");
1616 fb
= qemu_fopen_channel_output(QIO_CHANNEL(bioc
));
1617 object_unref(OBJECT(bioc
));
1620 * Make sure the receiver can get incoming pages before we send the rest
1623 qemu_savevm_send_postcopy_listen(fb
);
1625 qemu_savevm_state_complete_precopy(fb
, false);
1626 qemu_savevm_send_ping(fb
, 3);
1628 qemu_savevm_send_postcopy_run(fb
);
1630 /* <><> end of stuff going into the package */
1632 /* Now send that blob */
1633 if (qemu_savevm_send_packaged(ms
->to_dst_file
, bioc
->data
, bioc
->usage
)) {
1638 /* Send a notify to give a chance for anything that needs to happen
1639 * at the transition to postcopy and after the device state; in particular
1640 * spice needs to trigger a transition now
1642 ms
->postcopy_after_devices
= true;
1643 notifier_list_notify(&migration_state_notifiers
, ms
);
1645 ms
->downtime
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) - time_at_stop
;
1647 qemu_mutex_unlock_iothread();
1650 * Although this ping is just for debug, it could potentially be
1651 * used for getting a better measurement of downtime at the source.
1653 qemu_savevm_send_ping(ms
->to_dst_file
, 4);
1655 ret
= qemu_file_get_error(ms
->to_dst_file
);
1657 error_report("postcopy_start: Migration stream errored");
1658 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1659 MIGRATION_STATUS_FAILED
);
1667 migrate_set_state(&ms
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1668 MIGRATION_STATUS_FAILED
);
1669 qemu_mutex_unlock_iothread();
1674 * migration_completion: Used by migration_thread when there's not much left.
1675 * The caller 'breaks' the loop when this returns.
1677 * @s: Current migration state
1678 * @current_active_state: The migration state we expect to be in
1679 * @*old_vm_running: Pointer to old_vm_running flag
1680 * @*start_time: Pointer to time to update
1682 static void migration_completion(MigrationState
*s
, int current_active_state
,
1683 bool *old_vm_running
,
1684 int64_t *start_time
)
1688 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
1689 qemu_mutex_lock_iothread();
1690 *start_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1691 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER
);
1692 *old_vm_running
= runstate_is_running();
1693 ret
= global_state_store();
1696 ret
= vm_stop_force_state(RUN_STATE_FINISH_MIGRATE
);
1698 * Don't mark the image with BDRV_O_INACTIVE flag if
1699 * we will go into COLO stage later.
1701 if (ret
>= 0 && !migrate_colo_enabled()) {
1702 ret
= bdrv_inactivate_all();
1705 qemu_file_set_rate_limit(s
->to_dst_file
, INT64_MAX
);
1706 qemu_savevm_state_complete_precopy(s
->to_dst_file
, false);
1709 qemu_mutex_unlock_iothread();
1714 } else if (s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
1715 trace_migration_completion_postcopy_end();
1717 qemu_savevm_state_complete_postcopy(s
->to_dst_file
);
1718 trace_migration_completion_postcopy_end_after_complete();
1722 * If rp was opened we must clean up the thread before
1723 * cleaning everything else up (since if there are no failures
1724 * it will wait for the destination to send it's status in
1726 * Postcopy opens rp if enabled (even if it's not avtivated)
1728 if (migrate_postcopy_ram()) {
1730 trace_migration_completion_postcopy_end_before_rp();
1731 rp_error
= await_return_path_close_on_source(s
);
1732 trace_migration_completion_postcopy_end_after_rp(rp_error
);
1734 goto fail_invalidate
;
1738 if (qemu_file_get_error(s
->to_dst_file
)) {
1739 trace_migration_completion_file_err();
1740 goto fail_invalidate
;
1743 if (!migrate_colo_enabled()) {
1744 migrate_set_state(&s
->state
, current_active_state
,
1745 MIGRATION_STATUS_COMPLETED
);
1751 /* If not doing postcopy, vm_start() will be called: let's regain
1752 * control on images.
1754 if (s
->state
== MIGRATION_STATUS_ACTIVE
) {
1755 Error
*local_err
= NULL
;
1757 bdrv_invalidate_cache_all(&local_err
);
1759 error_report_err(local_err
);
1764 migrate_set_state(&s
->state
, current_active_state
,
1765 MIGRATION_STATUS_FAILED
);
1768 bool migrate_colo_enabled(void)
1770 MigrationState
*s
= migrate_get_current();
1771 return s
->enabled_capabilities
[MIGRATION_CAPABILITY_X_COLO
];
1775 * Master migration thread on the source VM.
1776 * It drives the migration and pumps the data down the outgoing channel.
1778 static void *migration_thread(void *opaque
)
1780 MigrationState
*s
= opaque
;
1781 /* Used by the bandwidth calcs, updated later */
1782 int64_t initial_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1783 int64_t setup_start
= qemu_clock_get_ms(QEMU_CLOCK_HOST
);
1784 int64_t initial_bytes
= 0;
1785 int64_t max_size
= 0;
1786 int64_t start_time
= initial_time
;
1788 bool old_vm_running
= false;
1789 bool entered_postcopy
= false;
1790 /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
1791 enum MigrationStatus current_active_state
= MIGRATION_STATUS_ACTIVE
;
1792 bool enable_colo
= migrate_colo_enabled();
1794 rcu_register_thread();
1796 qemu_savevm_state_header(s
->to_dst_file
);
1798 if (migrate_postcopy_ram()) {
1799 /* Now tell the dest that it should open its end so it can reply */
1800 qemu_savevm_send_open_return_path(s
->to_dst_file
);
1802 /* And do a ping that will make stuff easier to debug */
1803 qemu_savevm_send_ping(s
->to_dst_file
, 1);
1806 * Tell the destination that we *might* want to do postcopy later;
1807 * if the other end can't do postcopy it should fail now, nice and
1810 qemu_savevm_send_postcopy_advise(s
->to_dst_file
);
1813 qemu_savevm_state_begin(s
->to_dst_file
, &s
->params
);
1815 s
->setup_time
= qemu_clock_get_ms(QEMU_CLOCK_HOST
) - setup_start
;
1816 current_active_state
= MIGRATION_STATUS_ACTIVE
;
1817 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1818 MIGRATION_STATUS_ACTIVE
);
1820 trace_migration_thread_setup_complete();
1822 while (s
->state
== MIGRATION_STATUS_ACTIVE
||
1823 s
->state
== MIGRATION_STATUS_POSTCOPY_ACTIVE
) {
1824 int64_t current_time
;
1825 uint64_t pending_size
;
1827 if (!qemu_file_rate_limit(s
->to_dst_file
)) {
1828 uint64_t pend_post
, pend_nonpost
;
1830 qemu_savevm_state_pending(s
->to_dst_file
, max_size
, &pend_nonpost
,
1832 pending_size
= pend_nonpost
+ pend_post
;
1833 trace_migrate_pending(pending_size
, max_size
,
1834 pend_post
, pend_nonpost
);
1835 if (pending_size
&& pending_size
>= max_size
) {
1836 /* Still a significant amount to transfer */
1838 if (migrate_postcopy_ram() &&
1839 s
->state
!= MIGRATION_STATUS_POSTCOPY_ACTIVE
&&
1840 pend_nonpost
<= max_size
&&
1841 atomic_read(&s
->start_postcopy
)) {
1843 if (!postcopy_start(s
, &old_vm_running
)) {
1844 current_active_state
= MIGRATION_STATUS_POSTCOPY_ACTIVE
;
1845 entered_postcopy
= true;
1850 /* Just another iteration step */
1851 qemu_savevm_state_iterate(s
->to_dst_file
, entered_postcopy
);
1853 trace_migration_thread_low_pending(pending_size
);
1854 migration_completion(s
, current_active_state
,
1855 &old_vm_running
, &start_time
);
1860 if (qemu_file_get_error(s
->to_dst_file
)) {
1861 migrate_set_state(&s
->state
, current_active_state
,
1862 MIGRATION_STATUS_FAILED
);
1863 trace_migration_thread_file_err();
1866 current_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1867 if (current_time
>= initial_time
+ BUFFER_DELAY
) {
1868 uint64_t transferred_bytes
= qemu_ftell(s
->to_dst_file
) -
1870 uint64_t time_spent
= current_time
- initial_time
;
1871 double bandwidth
= (double)transferred_bytes
/ time_spent
;
1872 max_size
= bandwidth
* s
->parameters
.downtime_limit
;
1874 s
->mbps
= (((double) transferred_bytes
* 8.0) /
1875 ((double) time_spent
/ 1000.0)) / 1000.0 / 1000.0;
1877 trace_migrate_transferred(transferred_bytes
, time_spent
,
1878 bandwidth
, max_size
);
1879 /* if we haven't sent anything, we don't want to recalculate
1880 10000 is a small enough number for our purposes */
1881 if (s
->dirty_bytes_rate
&& transferred_bytes
> 10000) {
1882 s
->expected_downtime
= s
->dirty_bytes_rate
/ bandwidth
;
1885 qemu_file_reset_rate_limit(s
->to_dst_file
);
1886 initial_time
= current_time
;
1887 initial_bytes
= qemu_ftell(s
->to_dst_file
);
1889 if (qemu_file_rate_limit(s
->to_dst_file
)) {
1890 /* usleep expects microseconds */
1891 g_usleep((initial_time
+ BUFFER_DELAY
- current_time
)*1000);
1895 trace_migration_thread_after_loop();
1896 /* If we enabled cpu throttling for auto-converge, turn it off. */
1897 cpu_throttle_stop();
1898 end_time
= qemu_clock_get_ms(QEMU_CLOCK_REALTIME
);
1900 qemu_mutex_lock_iothread();
1902 * The resource has been allocated by migration will be reused in COLO
1903 * process, so don't release them.
1906 qemu_savevm_state_cleanup();
1908 if (s
->state
== MIGRATION_STATUS_COMPLETED
) {
1909 uint64_t transferred_bytes
= qemu_ftell(s
->to_dst_file
);
1910 s
->total_time
= end_time
- s
->total_time
;
1911 if (!entered_postcopy
) {
1912 s
->downtime
= end_time
- start_time
;
1914 if (s
->total_time
) {
1915 s
->mbps
= (((double) transferred_bytes
* 8.0) /
1916 ((double) s
->total_time
)) / 1000;
1918 runstate_set(RUN_STATE_POSTMIGRATE
);
1920 if (s
->state
== MIGRATION_STATUS_ACTIVE
&& enable_colo
) {
1921 migrate_start_colo_process(s
);
1922 qemu_savevm_state_cleanup();
1924 * Fixme: we will run VM in COLO no matter its old running state.
1925 * After exited COLO, we will keep running.
1927 old_vm_running
= true;
1929 if (old_vm_running
&& !entered_postcopy
) {
1932 if (runstate_check(RUN_STATE_FINISH_MIGRATE
)) {
1933 runstate_set(RUN_STATE_POSTMIGRATE
);
1937 qemu_bh_schedule(s
->cleanup_bh
);
1938 qemu_mutex_unlock_iothread();
1940 rcu_unregister_thread();
1944 void migrate_fd_connect(MigrationState
*s
)
1946 s
->expected_downtime
= s
->parameters
.downtime_limit
;
1947 s
->cleanup_bh
= qemu_bh_new(migrate_fd_cleanup
, s
);
1949 qemu_file_set_blocking(s
->to_dst_file
, true);
1950 qemu_file_set_rate_limit(s
->to_dst_file
,
1951 s
->parameters
.max_bandwidth
/ XFER_LIMIT_RATIO
);
1953 /* Notify before starting migration thread */
1954 notifier_list_notify(&migration_state_notifiers
, s
);
1957 * Open the return path; currently for postcopy but other things might
1960 if (migrate_postcopy_ram()) {
1961 if (open_return_path_on_source(s
)) {
1962 error_report("Unable to open return-path for postcopy");
1963 migrate_set_state(&s
->state
, MIGRATION_STATUS_SETUP
,
1964 MIGRATION_STATUS_FAILED
);
1965 migrate_fd_cleanup(s
);
1970 migrate_compress_threads_create();
1971 qemu_thread_create(&s
->thread
, "migration", migration_thread
, s
,
1972 QEMU_THREAD_JOINABLE
);
1973 s
->migration_thread_running
= true;
1976 PostcopyState
postcopy_state_get(void)
1978 return atomic_mb_read(&incoming_postcopy_state
);
1981 /* Set the state and return the old state */
1982 PostcopyState
postcopy_state_set(PostcopyState new_state
)
1984 return atomic_xchg(&incoming_postcopy_state
, new_state
);