4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009-2015 Red Hat Inc
8 * Juan Quintela <quintela@redhat.com>
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
29 #include "qemu/osdep.h"
30 #include "hw/boards.h"
31 #include "hw/xen/xen.h"
33 #include "migration.h"
34 #include "migration/snapshot.h"
35 #include "migration/misc.h"
36 #include "migration/register.h"
37 #include "migration/global_state.h"
39 #include "qemu-file-channel.h"
40 #include "qemu-file.h"
42 #include "postcopy-ram.h"
43 #include "qapi/error.h"
44 #include "qapi/qapi-commands-migration.h"
45 #include "qapi/qapi-commands-misc.h"
46 #include "qapi/qmp/qerror.h"
47 #include "qemu/error-report.h"
48 #include "sysemu/cpus.h"
49 #include "exec/memory.h"
50 #include "exec/target_page.h"
53 #include "block/snapshot.h"
54 #include "qemu/cutils.h"
55 #include "io/channel-buffer.h"
56 #include "io/channel-file.h"
57 #include "sysemu/replay.h"
59 #include "migration/colo.h"
60 #include "qemu/bitmap.h"
61 #include "net/announce.h"
63 const unsigned int postcopy_ram_discard_version
= 0;
65 /* Subcommands for QEMU_VM_COMMAND */
67 MIG_CMD_INVALID
= 0, /* Must be 0 */
68 MIG_CMD_OPEN_RETURN_PATH
, /* Tell the dest to open the Return path */
69 MIG_CMD_PING
, /* Request a PONG on the RP */
71 MIG_CMD_POSTCOPY_ADVISE
, /* Prior to any page transfers, just
72 warn we might want to do PC */
73 MIG_CMD_POSTCOPY_LISTEN
, /* Start listening for incoming
74 pages as it's running. */
75 MIG_CMD_POSTCOPY_RUN
, /* Start execution */
77 MIG_CMD_POSTCOPY_RAM_DISCARD
, /* A list of pages to discard that
78 were previously sent during
79 precopy but are dirty. */
80 MIG_CMD_PACKAGED
, /* Send a wrapped stream within this stream */
81 MIG_CMD_ENABLE_COLO
, /* Enable COLO */
82 MIG_CMD_POSTCOPY_RESUME
, /* resume postcopy on dest */
83 MIG_CMD_RECV_BITMAP
, /* Request for recved bitmap on dst */
87 #define MAX_VM_CMD_PACKAGED_SIZE UINT32_MAX
88 static struct mig_cmd_args
{
89 ssize_t len
; /* -1 = variable */
92 [MIG_CMD_INVALID
] = { .len
= -1, .name
= "INVALID" },
93 [MIG_CMD_OPEN_RETURN_PATH
] = { .len
= 0, .name
= "OPEN_RETURN_PATH" },
94 [MIG_CMD_PING
] = { .len
= sizeof(uint32_t), .name
= "PING" },
95 [MIG_CMD_POSTCOPY_ADVISE
] = { .len
= -1, .name
= "POSTCOPY_ADVISE" },
96 [MIG_CMD_POSTCOPY_LISTEN
] = { .len
= 0, .name
= "POSTCOPY_LISTEN" },
97 [MIG_CMD_POSTCOPY_RUN
] = { .len
= 0, .name
= "POSTCOPY_RUN" },
98 [MIG_CMD_POSTCOPY_RAM_DISCARD
] = {
99 .len
= -1, .name
= "POSTCOPY_RAM_DISCARD" },
100 [MIG_CMD_POSTCOPY_RESUME
] = { .len
= 0, .name
= "POSTCOPY_RESUME" },
101 [MIG_CMD_PACKAGED
] = { .len
= 4, .name
= "PACKAGED" },
102 [MIG_CMD_RECV_BITMAP
] = { .len
= -1, .name
= "RECV_BITMAP" },
103 [MIG_CMD_MAX
] = { .len
= -1, .name
= "MAX" },
106 /* Note for MIG_CMD_POSTCOPY_ADVISE:
107 * The format of arguments is depending on postcopy mode:
108 * - postcopy RAM only
109 * uint64_t host page size
110 * uint64_t taget page size
112 * - postcopy RAM and postcopy dirty bitmaps
113 * format is the same as for postcopy RAM only
115 * - postcopy dirty bitmaps only
116 * Nothing. Command length field is 0.
118 * Be careful: adding a new postcopy entity with some other parameters should
119 * not break format self-description ability. Good way is to introduce some
120 * generic extendable format with an exception for two old entities.
123 /***********************************************************/
124 /* savevm/loadvm support */
126 static ssize_t
block_writev_buffer(void *opaque
, struct iovec
*iov
, int iovcnt
,
132 qemu_iovec_init_external(&qiov
, iov
, iovcnt
);
133 ret
= bdrv_writev_vmstate(opaque
, &qiov
, pos
);
141 static ssize_t
block_get_buffer(void *opaque
, uint8_t *buf
, int64_t pos
,
144 return bdrv_load_vmstate(opaque
, buf
, pos
, size
);
147 static int bdrv_fclose(void *opaque
)
149 return bdrv_flush(opaque
);
152 static const QEMUFileOps bdrv_read_ops
= {
153 .get_buffer
= block_get_buffer
,
157 static const QEMUFileOps bdrv_write_ops
= {
158 .writev_buffer
= block_writev_buffer
,
162 static QEMUFile
*qemu_fopen_bdrv(BlockDriverState
*bs
, int is_writable
)
165 return qemu_fopen_ops(bs
, &bdrv_write_ops
);
167 return qemu_fopen_ops(bs
, &bdrv_read_ops
);
171 /* QEMUFile timer support.
172 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
175 void timer_put(QEMUFile
*f
, QEMUTimer
*ts
)
177 uint64_t expire_time
;
179 expire_time
= timer_expire_time_ns(ts
);
180 qemu_put_be64(f
, expire_time
);
183 void timer_get(QEMUFile
*f
, QEMUTimer
*ts
)
185 uint64_t expire_time
;
187 expire_time
= qemu_get_be64(f
);
188 if (expire_time
!= -1) {
189 timer_mod_ns(ts
, expire_time
);
196 /* VMState timer support.
197 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
200 static int get_timer(QEMUFile
*f
, void *pv
, size_t size
,
201 const VMStateField
*field
)
208 static int put_timer(QEMUFile
*f
, void *pv
, size_t size
,
209 const VMStateField
*field
, QJSON
*vmdesc
)
217 const VMStateInfo vmstate_info_timer
= {
224 typedef struct CompatEntry
{
229 typedef struct SaveStateEntry
{
230 QTAILQ_ENTRY(SaveStateEntry
) entry
;
235 /* version id read from the stream */
238 /* section id read from the stream */
240 const SaveVMHandlers
*ops
;
241 const VMStateDescription
*vmsd
;
247 typedef struct SaveState
{
248 QTAILQ_HEAD(, SaveStateEntry
) handlers
;
249 int global_section_id
;
252 uint32_t target_page_bits
;
254 MigrationCapability
*capabilities
;
257 static SaveState savevm_state
= {
258 .handlers
= QTAILQ_HEAD_INITIALIZER(savevm_state
.handlers
),
259 .global_section_id
= 0,
262 static bool should_validate_capability(int capability
)
264 assert(capability
>= 0 && capability
< MIGRATION_CAPABILITY__MAX
);
265 /* Validate only new capabilities to keep compatibility. */
266 switch (capability
) {
267 case MIGRATION_CAPABILITY_X_IGNORE_SHARED
:
274 static uint32_t get_validatable_capabilities_count(void)
276 MigrationState
*s
= migrate_get_current();
279 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
280 if (should_validate_capability(i
) && s
->enabled_capabilities
[i
]) {
287 static int configuration_pre_save(void *opaque
)
289 SaveState
*state
= opaque
;
290 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
291 MigrationState
*s
= migrate_get_current();
294 state
->len
= strlen(current_name
);
295 state
->name
= current_name
;
296 state
->target_page_bits
= qemu_target_page_bits();
298 state
->caps_count
= get_validatable_capabilities_count();
299 state
->capabilities
= g_renew(MigrationCapability
, state
->capabilities
,
301 for (i
= j
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
302 if (should_validate_capability(i
) && s
->enabled_capabilities
[i
]) {
303 state
->capabilities
[j
++] = i
;
310 static int configuration_pre_load(void *opaque
)
312 SaveState
*state
= opaque
;
314 /* If there is no target-page-bits subsection it means the source
315 * predates the variable-target-page-bits support and is using the
316 * minimum possible value for this CPU.
318 state
->target_page_bits
= qemu_target_page_bits_min();
322 static bool configuration_validate_capabilities(SaveState
*state
)
325 MigrationState
*s
= migrate_get_current();
326 unsigned long *source_caps_bm
;
329 source_caps_bm
= bitmap_new(MIGRATION_CAPABILITY__MAX
);
330 for (i
= 0; i
< state
->caps_count
; i
++) {
331 MigrationCapability capability
= state
->capabilities
[i
];
332 set_bit(capability
, source_caps_bm
);
335 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
336 bool source_state
, target_state
;
337 if (!should_validate_capability(i
)) {
340 source_state
= test_bit(i
, source_caps_bm
);
341 target_state
= s
->enabled_capabilities
[i
];
342 if (source_state
!= target_state
) {
343 error_report("Capability %s is %s, but received capability is %s",
344 MigrationCapability_str(i
),
345 target_state
? "on" : "off",
346 source_state
? "on" : "off");
348 /* Don't break here to report all failed capabilities */
352 g_free(source_caps_bm
);
356 static int configuration_post_load(void *opaque
, int version_id
)
358 SaveState
*state
= opaque
;
359 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
361 if (strncmp(state
->name
, current_name
, state
->len
) != 0) {
362 error_report("Machine type received is '%.*s' and local is '%s'",
363 (int) state
->len
, state
->name
, current_name
);
367 if (state
->target_page_bits
!= qemu_target_page_bits()) {
368 error_report("Received TARGET_PAGE_BITS is %d but local is %d",
369 state
->target_page_bits
, qemu_target_page_bits());
373 if (!configuration_validate_capabilities(state
)) {
380 static int get_capability(QEMUFile
*f
, void *pv
, size_t size
,
381 const VMStateField
*field
)
383 MigrationCapability
*capability
= pv
;
384 char capability_str
[UINT8_MAX
+ 1];
388 len
= qemu_get_byte(f
);
389 qemu_get_buffer(f
, (uint8_t *)capability_str
, len
);
390 capability_str
[len
] = '\0';
391 for (i
= 0; i
< MIGRATION_CAPABILITY__MAX
; i
++) {
392 if (!strcmp(MigrationCapability_str(i
), capability_str
)) {
397 error_report("Received unknown capability %s", capability_str
);
401 static int put_capability(QEMUFile
*f
, void *pv
, size_t size
,
402 const VMStateField
*field
, QJSON
*vmdesc
)
404 MigrationCapability
*capability
= pv
;
405 const char *capability_str
= MigrationCapability_str(*capability
);
406 size_t len
= strlen(capability_str
);
407 assert(len
<= UINT8_MAX
);
409 qemu_put_byte(f
, len
);
410 qemu_put_buffer(f
, (uint8_t *)capability_str
, len
);
414 static const VMStateInfo vmstate_info_capability
= {
415 .name
= "capability",
416 .get
= get_capability
,
417 .put
= put_capability
,
420 /* The target-page-bits subsection is present only if the
421 * target page size is not the same as the default (ie the
422 * minimum page size for a variable-page-size guest CPU).
423 * If it is present then it contains the actual target page
424 * bits for the machine, and migration will fail if the
425 * two ends don't agree about it.
427 static bool vmstate_target_page_bits_needed(void *opaque
)
429 return qemu_target_page_bits()
430 > qemu_target_page_bits_min();
433 static const VMStateDescription vmstate_target_page_bits
= {
434 .name
= "configuration/target-page-bits",
436 .minimum_version_id
= 1,
437 .needed
= vmstate_target_page_bits_needed
,
438 .fields
= (VMStateField
[]) {
439 VMSTATE_UINT32(target_page_bits
, SaveState
),
440 VMSTATE_END_OF_LIST()
444 static bool vmstate_capabilites_needed(void *opaque
)
446 return get_validatable_capabilities_count() > 0;
449 static const VMStateDescription vmstate_capabilites
= {
450 .name
= "configuration/capabilities",
452 .minimum_version_id
= 1,
453 .needed
= vmstate_capabilites_needed
,
454 .fields
= (VMStateField
[]) {
455 VMSTATE_UINT32_V(caps_count
, SaveState
, 1),
456 VMSTATE_VARRAY_UINT32_ALLOC(capabilities
, SaveState
, caps_count
, 1,
457 vmstate_info_capability
,
458 MigrationCapability
),
459 VMSTATE_END_OF_LIST()
463 static const VMStateDescription vmstate_configuration
= {
464 .name
= "configuration",
466 .pre_load
= configuration_pre_load
,
467 .post_load
= configuration_post_load
,
468 .pre_save
= configuration_pre_save
,
469 .fields
= (VMStateField
[]) {
470 VMSTATE_UINT32(len
, SaveState
),
471 VMSTATE_VBUFFER_ALLOC_UINT32(name
, SaveState
, 0, NULL
, len
),
472 VMSTATE_END_OF_LIST()
474 .subsections
= (const VMStateDescription
*[]) {
475 &vmstate_target_page_bits
,
476 &vmstate_capabilites
,
481 static void dump_vmstate_vmsd(FILE *out_file
,
482 const VMStateDescription
*vmsd
, int indent
,
485 static void dump_vmstate_vmsf(FILE *out_file
, const VMStateField
*field
,
488 fprintf(out_file
, "%*s{\n", indent
, "");
490 fprintf(out_file
, "%*s\"field\": \"%s\",\n", indent
, "", field
->name
);
491 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
493 fprintf(out_file
, "%*s\"field_exists\": %s,\n", indent
, "",
494 field
->field_exists
? "true" : "false");
495 fprintf(out_file
, "%*s\"size\": %zu", indent
, "", field
->size
);
496 if (field
->vmsd
!= NULL
) {
497 fprintf(out_file
, ",\n");
498 dump_vmstate_vmsd(out_file
, field
->vmsd
, indent
, false);
500 fprintf(out_file
, "\n%*s}", indent
- 2, "");
503 static void dump_vmstate_vmss(FILE *out_file
,
504 const VMStateDescription
**subsection
,
507 if (*subsection
!= NULL
) {
508 dump_vmstate_vmsd(out_file
, *subsection
, indent
, true);
512 static void dump_vmstate_vmsd(FILE *out_file
,
513 const VMStateDescription
*vmsd
, int indent
,
517 fprintf(out_file
, "%*s{\n", indent
, "");
519 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", "Description");
522 fprintf(out_file
, "%*s\"name\": \"%s\",\n", indent
, "", vmsd
->name
);
523 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
525 fprintf(out_file
, "%*s\"minimum_version_id\": %d", indent
, "",
526 vmsd
->minimum_version_id
);
527 if (vmsd
->fields
!= NULL
) {
528 const VMStateField
*field
= vmsd
->fields
;
531 fprintf(out_file
, ",\n%*s\"Fields\": [\n", indent
, "");
533 while (field
->name
!= NULL
) {
534 if (field
->flags
& VMS_MUST_EXIST
) {
535 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
540 fprintf(out_file
, ",\n");
542 dump_vmstate_vmsf(out_file
, field
, indent
+ 2);
546 fprintf(out_file
, "\n%*s]", indent
, "");
548 if (vmsd
->subsections
!= NULL
) {
549 const VMStateDescription
**subsection
= vmsd
->subsections
;
552 fprintf(out_file
, ",\n%*s\"Subsections\": [\n", indent
, "");
554 while (*subsection
!= NULL
) {
556 fprintf(out_file
, ",\n");
558 dump_vmstate_vmss(out_file
, subsection
, indent
+ 2);
562 fprintf(out_file
, "\n%*s]", indent
, "");
564 fprintf(out_file
, "\n%*s}", indent
- 2, "");
567 static void dump_machine_type(FILE *out_file
)
571 mc
= MACHINE_GET_CLASS(current_machine
);
573 fprintf(out_file
, " \"vmschkmachine\": {\n");
574 fprintf(out_file
, " \"Name\": \"%s\"\n", mc
->name
);
575 fprintf(out_file
, " },\n");
578 void dump_vmstate_json_to_file(FILE *out_file
)
583 fprintf(out_file
, "{\n");
584 dump_machine_type(out_file
);
587 list
= object_class_get_list(TYPE_DEVICE
, true);
588 for (elt
= list
; elt
; elt
= elt
->next
) {
589 DeviceClass
*dc
= OBJECT_CLASS_CHECK(DeviceClass
, elt
->data
,
599 fprintf(out_file
, ",\n");
601 name
= object_class_get_name(OBJECT_CLASS(dc
));
602 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", name
);
604 fprintf(out_file
, "%*s\"Name\": \"%s\",\n", indent
, "", name
);
605 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
606 dc
->vmsd
->version_id
);
607 fprintf(out_file
, "%*s\"minimum_version_id\": %d,\n", indent
, "",
608 dc
->vmsd
->minimum_version_id
);
610 dump_vmstate_vmsd(out_file
, dc
->vmsd
, indent
, false);
612 fprintf(out_file
, "\n%*s}", indent
- 2, "");
615 fprintf(out_file
, "\n}\n");
619 static int calculate_new_instance_id(const char *idstr
)
624 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
625 if (strcmp(idstr
, se
->idstr
) == 0
626 && instance_id
<= se
->instance_id
) {
627 instance_id
= se
->instance_id
+ 1;
633 static int calculate_compat_instance_id(const char *idstr
)
638 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
643 if (strcmp(idstr
, se
->compat
->idstr
) == 0
644 && instance_id
<= se
->compat
->instance_id
) {
645 instance_id
= se
->compat
->instance_id
+ 1;
651 static inline MigrationPriority
save_state_priority(SaveStateEntry
*se
)
654 return se
->vmsd
->priority
;
656 return MIG_PRI_DEFAULT
;
659 static void savevm_state_handler_insert(SaveStateEntry
*nse
)
661 MigrationPriority priority
= save_state_priority(nse
);
664 assert(priority
<= MIG_PRI_MAX
);
666 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
667 if (save_state_priority(se
) < priority
) {
673 QTAILQ_INSERT_BEFORE(se
, nse
, entry
);
675 QTAILQ_INSERT_TAIL(&savevm_state
.handlers
, nse
, entry
);
679 /* TODO: Individual devices generally have very little idea about the rest
680 of the system, so instance_id should be removed/replaced.
681 Meanwhile pass -1 as instance_id if you do not already have a clearly
682 distinguishing id for all instances of your device class. */
683 int register_savevm_live(DeviceState
*dev
,
687 const SaveVMHandlers
*ops
,
692 se
= g_new0(SaveStateEntry
, 1);
693 se
->version_id
= version_id
;
694 se
->section_id
= savevm_state
.global_section_id
++;
698 /* if this is a live_savem then set is_ram */
699 if (ops
->save_setup
!= NULL
) {
704 char *id
= qdev_get_dev_path(dev
);
706 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
708 error_report("Path too long for VMState (%s)", id
);
716 se
->compat
= g_new0(CompatEntry
, 1);
717 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), idstr
);
718 se
->compat
->instance_id
= instance_id
== -1 ?
719 calculate_compat_instance_id(idstr
) : instance_id
;
723 pstrcat(se
->idstr
, sizeof(se
->idstr
), idstr
);
725 if (instance_id
== -1) {
726 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
728 se
->instance_id
= instance_id
;
730 assert(!se
->compat
|| se
->instance_id
== 0);
731 savevm_state_handler_insert(se
);
735 void unregister_savevm(DeviceState
*dev
, const char *idstr
, void *opaque
)
737 SaveStateEntry
*se
, *new_se
;
741 char *path
= qdev_get_dev_path(dev
);
743 pstrcpy(id
, sizeof(id
), path
);
744 pstrcat(id
, sizeof(id
), "/");
748 pstrcat(id
, sizeof(id
), idstr
);
750 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
751 if (strcmp(se
->idstr
, id
) == 0 && se
->opaque
== opaque
) {
752 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
759 int vmstate_register_with_alias_id(DeviceState
*dev
, int instance_id
,
760 const VMStateDescription
*vmsd
,
761 void *opaque
, int alias_id
,
762 int required_for_version
,
767 /* If this triggers, alias support can be dropped for the vmsd. */
768 assert(alias_id
== -1 || required_for_version
>= vmsd
->minimum_version_id
);
770 se
= g_new0(SaveStateEntry
, 1);
771 se
->version_id
= vmsd
->version_id
;
772 se
->section_id
= savevm_state
.global_section_id
++;
775 se
->alias_id
= alias_id
;
778 char *id
= qdev_get_dev_path(dev
);
780 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
782 error_setg(errp
, "Path too long for VMState (%s)", id
);
790 se
->compat
= g_new0(CompatEntry
, 1);
791 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), vmsd
->name
);
792 se
->compat
->instance_id
= instance_id
== -1 ?
793 calculate_compat_instance_id(vmsd
->name
) : instance_id
;
797 pstrcat(se
->idstr
, sizeof(se
->idstr
), vmsd
->name
);
799 if (instance_id
== -1) {
800 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
802 se
->instance_id
= instance_id
;
804 assert(!se
->compat
|| se
->instance_id
== 0);
805 savevm_state_handler_insert(se
);
809 void vmstate_unregister(DeviceState
*dev
, const VMStateDescription
*vmsd
,
812 SaveStateEntry
*se
, *new_se
;
814 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
815 if (se
->vmsd
== vmsd
&& se
->opaque
== opaque
) {
816 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
823 static int vmstate_load(QEMUFile
*f
, SaveStateEntry
*se
)
825 trace_vmstate_load(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
826 if (!se
->vmsd
) { /* Old style */
827 return se
->ops
->load_state(f
, se
->opaque
, se
->load_version_id
);
829 return vmstate_load_state(f
, se
->vmsd
, se
->opaque
, se
->load_version_id
);
832 static void vmstate_save_old_style(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
834 int64_t old_offset
, size
;
836 old_offset
= qemu_ftell_fast(f
);
837 se
->ops
->save_state(f
, se
->opaque
);
838 size
= qemu_ftell_fast(f
) - old_offset
;
841 json_prop_int(vmdesc
, "size", size
);
842 json_start_array(vmdesc
, "fields");
843 json_start_object(vmdesc
, NULL
);
844 json_prop_str(vmdesc
, "name", "data");
845 json_prop_int(vmdesc
, "size", size
);
846 json_prop_str(vmdesc
, "type", "buffer");
847 json_end_object(vmdesc
);
848 json_end_array(vmdesc
);
852 static int vmstate_save(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
854 trace_vmstate_save(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
856 vmstate_save_old_style(f
, se
, vmdesc
);
859 return vmstate_save_state(f
, se
->vmsd
, se
->opaque
, vmdesc
);
863 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
865 static void save_section_header(QEMUFile
*f
, SaveStateEntry
*se
,
866 uint8_t section_type
)
868 qemu_put_byte(f
, section_type
);
869 qemu_put_be32(f
, se
->section_id
);
871 if (section_type
== QEMU_VM_SECTION_FULL
||
872 section_type
== QEMU_VM_SECTION_START
) {
874 size_t len
= strlen(se
->idstr
);
875 qemu_put_byte(f
, len
);
876 qemu_put_buffer(f
, (uint8_t *)se
->idstr
, len
);
878 qemu_put_be32(f
, se
->instance_id
);
879 qemu_put_be32(f
, se
->version_id
);
884 * Write a footer onto device sections that catches cases misformatted device
887 static void save_section_footer(QEMUFile
*f
, SaveStateEntry
*se
)
889 if (migrate_get_current()->send_section_footer
) {
890 qemu_put_byte(f
, QEMU_VM_SECTION_FOOTER
);
891 qemu_put_be32(f
, se
->section_id
);
896 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
897 * command and associated data.
899 * @f: File to send command on
900 * @command: Command type to send
901 * @len: Length of associated data
902 * @data: Data associated with command.
904 static void qemu_savevm_command_send(QEMUFile
*f
,
905 enum qemu_vm_cmd command
,
909 trace_savevm_command_send(command
, len
);
910 qemu_put_byte(f
, QEMU_VM_COMMAND
);
911 qemu_put_be16(f
, (uint16_t)command
);
912 qemu_put_be16(f
, len
);
913 qemu_put_buffer(f
, data
, len
);
917 void qemu_savevm_send_colo_enable(QEMUFile
*f
)
919 trace_savevm_send_colo_enable();
920 qemu_savevm_command_send(f
, MIG_CMD_ENABLE_COLO
, 0, NULL
);
923 void qemu_savevm_send_ping(QEMUFile
*f
, uint32_t value
)
927 trace_savevm_send_ping(value
);
928 buf
= cpu_to_be32(value
);
929 qemu_savevm_command_send(f
, MIG_CMD_PING
, sizeof(value
), (uint8_t *)&buf
);
932 void qemu_savevm_send_open_return_path(QEMUFile
*f
)
934 trace_savevm_send_open_return_path();
935 qemu_savevm_command_send(f
, MIG_CMD_OPEN_RETURN_PATH
, 0, NULL
);
938 /* We have a buffer of data to send; we don't want that all to be loaded
939 * by the command itself, so the command contains just the length of the
940 * extra buffer that we then send straight after it.
941 * TODO: Must be a better way to organise that
947 int qemu_savevm_send_packaged(QEMUFile
*f
, const uint8_t *buf
, size_t len
)
951 if (len
> MAX_VM_CMD_PACKAGED_SIZE
) {
952 error_report("%s: Unreasonably large packaged state: %zu",
957 tmp
= cpu_to_be32(len
);
959 trace_qemu_savevm_send_packaged();
960 qemu_savevm_command_send(f
, MIG_CMD_PACKAGED
, 4, (uint8_t *)&tmp
);
962 qemu_put_buffer(f
, buf
, len
);
967 /* Send prior to any postcopy transfer */
968 void qemu_savevm_send_postcopy_advise(QEMUFile
*f
)
970 if (migrate_postcopy_ram()) {
972 tmp
[0] = cpu_to_be64(ram_pagesize_summary());
973 tmp
[1] = cpu_to_be64(qemu_target_page_size());
975 trace_qemu_savevm_send_postcopy_advise();
976 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_ADVISE
,
979 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_ADVISE
, 0, NULL
);
983 /* Sent prior to starting the destination running in postcopy, discard pages
984 * that have already been sent but redirtied on the source.
985 * CMD_POSTCOPY_RAM_DISCARD consist of:
987 * byte Length of name field (not including 0)
988 * n x byte RAM block name
989 * byte 0 terminator (just for safety)
990 * n x Byte ranges within the named RAMBlock
991 * be64 Start of the range
994 * name: RAMBlock name that these entries are part of
995 * len: Number of page entries
996 * start_list: 'len' addresses
997 * length_list: 'len' addresses
1000 void qemu_savevm_send_postcopy_ram_discard(QEMUFile
*f
, const char *name
,
1002 uint64_t *start_list
,
1003 uint64_t *length_list
)
1008 size_t name_len
= strlen(name
);
1010 trace_qemu_savevm_send_postcopy_ram_discard(name
, len
);
1011 assert(name_len
< 256);
1012 buf
= g_malloc0(1 + 1 + name_len
+ 1 + (8 + 8) * len
);
1013 buf
[0] = postcopy_ram_discard_version
;
1015 memcpy(buf
+ 2, name
, name_len
);
1016 tmplen
= 2 + name_len
;
1017 buf
[tmplen
++] = '\0';
1019 for (t
= 0; t
< len
; t
++) {
1020 stq_be_p(buf
+ tmplen
, start_list
[t
]);
1022 stq_be_p(buf
+ tmplen
, length_list
[t
]);
1025 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RAM_DISCARD
, tmplen
, buf
);
1029 /* Get the destination into a state where it can receive postcopy data. */
1030 void qemu_savevm_send_postcopy_listen(QEMUFile
*f
)
1032 trace_savevm_send_postcopy_listen();
1033 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_LISTEN
, 0, NULL
);
1036 /* Kick the destination into running */
1037 void qemu_savevm_send_postcopy_run(QEMUFile
*f
)
1039 trace_savevm_send_postcopy_run();
1040 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RUN
, 0, NULL
);
1043 void qemu_savevm_send_postcopy_resume(QEMUFile
*f
)
1045 trace_savevm_send_postcopy_resume();
1046 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RESUME
, 0, NULL
);
1049 void qemu_savevm_send_recv_bitmap(QEMUFile
*f
, char *block_name
)
1054 trace_savevm_send_recv_bitmap(block_name
);
1056 buf
[0] = len
= strlen(block_name
);
1057 memcpy(buf
+ 1, block_name
, len
);
1059 qemu_savevm_command_send(f
, MIG_CMD_RECV_BITMAP
, len
+ 1, (uint8_t *)buf
);
1062 bool qemu_savevm_state_blocked(Error
**errp
)
1066 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1067 if (se
->vmsd
&& se
->vmsd
->unmigratable
) {
1068 error_setg(errp
, "State blocked by non-migratable device '%s'",
1076 void qemu_savevm_state_header(QEMUFile
*f
)
1078 trace_savevm_state_header();
1079 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
1080 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
1082 if (migrate_get_current()->send_configuration
) {
1083 qemu_put_byte(f
, QEMU_VM_CONFIGURATION
);
1084 vmstate_save_state(f
, &vmstate_configuration
, &savevm_state
, 0);
1088 void qemu_savevm_state_setup(QEMUFile
*f
)
1093 trace_savevm_state_setup();
1094 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1095 if (!se
->ops
|| !se
->ops
->save_setup
) {
1098 if (se
->ops
&& se
->ops
->is_active
) {
1099 if (!se
->ops
->is_active(se
->opaque
)) {
1103 save_section_header(f
, se
, QEMU_VM_SECTION_START
);
1105 ret
= se
->ops
->save_setup(f
, se
->opaque
);
1106 save_section_footer(f
, se
);
1108 qemu_file_set_error(f
, ret
);
1114 int qemu_savevm_state_resume_prepare(MigrationState
*s
)
1119 trace_savevm_state_resume_prepare();
1121 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1122 if (!se
->ops
|| !se
->ops
->resume_prepare
) {
1125 if (se
->ops
&& se
->ops
->is_active
) {
1126 if (!se
->ops
->is_active(se
->opaque
)) {
1130 ret
= se
->ops
->resume_prepare(s
, se
->opaque
);
1140 * this function has three return values:
1141 * negative: there was one error, and we have -errno.
1142 * 0 : We haven't finished, caller have to go again
1143 * 1 : We have finished, we can go to complete phase
1145 int qemu_savevm_state_iterate(QEMUFile
*f
, bool postcopy
)
1150 trace_savevm_state_iterate();
1151 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1152 if (!se
->ops
|| !se
->ops
->save_live_iterate
) {
1155 if (se
->ops
&& se
->ops
->is_active
) {
1156 if (!se
->ops
->is_active(se
->opaque
)) {
1160 if (se
->ops
&& se
->ops
->is_active_iterate
) {
1161 if (!se
->ops
->is_active_iterate(se
->opaque
)) {
1166 * In the postcopy phase, any device that doesn't know how to
1167 * do postcopy should have saved it's state in the _complete
1168 * call that's already run, it might get confused if we call
1169 * iterate afterwards.
1172 !(se
->ops
->has_postcopy
&& se
->ops
->has_postcopy(se
->opaque
))) {
1175 if (qemu_file_rate_limit(f
)) {
1178 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1180 save_section_header(f
, se
, QEMU_VM_SECTION_PART
);
1182 ret
= se
->ops
->save_live_iterate(f
, se
->opaque
);
1183 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1184 save_section_footer(f
, se
);
1187 qemu_file_set_error(f
, ret
);
1190 /* Do not proceed to the next vmstate before this one reported
1191 completion of the current stage. This serializes the migration
1192 and reduces the probability that a faster changing state is
1193 synchronized over and over again. */
1200 static bool should_send_vmdesc(void)
1202 MachineState
*machine
= MACHINE(qdev_get_machine());
1203 bool in_postcopy
= migration_in_postcopy();
1204 return !machine
->suppress_vmdesc
&& !in_postcopy
;
1208 * Calls the save_live_complete_postcopy methods
1209 * causing the last few pages to be sent immediately and doing any associated
1211 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
1212 * all the other devices, but that happens at the point we switch to postcopy.
1214 void qemu_savevm_state_complete_postcopy(QEMUFile
*f
)
1219 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1220 if (!se
->ops
|| !se
->ops
->save_live_complete_postcopy
) {
1223 if (se
->ops
&& se
->ops
->is_active
) {
1224 if (!se
->ops
->is_active(se
->opaque
)) {
1228 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1230 qemu_put_byte(f
, QEMU_VM_SECTION_END
);
1231 qemu_put_be32(f
, se
->section_id
);
1233 ret
= se
->ops
->save_live_complete_postcopy(f
, se
->opaque
);
1234 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1235 save_section_footer(f
, se
);
1237 qemu_file_set_error(f
, ret
);
1242 qemu_put_byte(f
, QEMU_VM_EOF
);
1246 int qemu_savevm_state_complete_precopy(QEMUFile
*f
, bool iterable_only
,
1247 bool inactivate_disks
)
1253 bool in_postcopy
= migration_in_postcopy();
1255 trace_savevm_state_complete_precopy();
1257 cpu_synchronize_all_states();
1259 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1261 (in_postcopy
&& se
->ops
->has_postcopy
&&
1262 se
->ops
->has_postcopy(se
->opaque
)) ||
1263 (in_postcopy
&& !iterable_only
) ||
1264 !se
->ops
->save_live_complete_precopy
) {
1268 if (se
->ops
&& se
->ops
->is_active
) {
1269 if (!se
->ops
->is_active(se
->opaque
)) {
1273 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1275 save_section_header(f
, se
, QEMU_VM_SECTION_END
);
1277 ret
= se
->ops
->save_live_complete_precopy(f
, se
->opaque
);
1278 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1279 save_section_footer(f
, se
);
1281 qemu_file_set_error(f
, ret
);
1286 if (iterable_only
) {
1290 vmdesc
= qjson_new();
1291 json_prop_int(vmdesc
, "page_size", qemu_target_page_size());
1292 json_start_array(vmdesc
, "devices");
1293 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1295 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1298 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1299 trace_savevm_section_skip(se
->idstr
, se
->section_id
);
1303 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1305 json_start_object(vmdesc
, NULL
);
1306 json_prop_str(vmdesc
, "name", se
->idstr
);
1307 json_prop_int(vmdesc
, "instance_id", se
->instance_id
);
1309 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1310 ret
= vmstate_save(f
, se
, vmdesc
);
1312 qemu_file_set_error(f
, ret
);
1315 trace_savevm_section_end(se
->idstr
, se
->section_id
, 0);
1316 save_section_footer(f
, se
);
1318 json_end_object(vmdesc
);
1321 if (inactivate_disks
) {
1322 /* Inactivate before sending QEMU_VM_EOF so that the
1323 * bdrv_invalidate_cache_all() on the other end won't fail. */
1324 ret
= bdrv_inactivate_all();
1326 error_report("%s: bdrv_inactivate_all() failed (%d)",
1328 qemu_file_set_error(f
, ret
);
1333 /* Postcopy stream will still be going */
1334 qemu_put_byte(f
, QEMU_VM_EOF
);
1337 json_end_array(vmdesc
);
1338 qjson_finish(vmdesc
);
1339 vmdesc_len
= strlen(qjson_get_str(vmdesc
));
1341 if (should_send_vmdesc()) {
1342 qemu_put_byte(f
, QEMU_VM_VMDESCRIPTION
);
1343 qemu_put_be32(f
, vmdesc_len
);
1344 qemu_put_buffer(f
, (uint8_t *)qjson_get_str(vmdesc
), vmdesc_len
);
1346 qjson_destroy(vmdesc
);
1352 /* Give an estimate of the amount left to be transferred,
1353 * the result is split into the amount for units that can and
1354 * for units that can't do postcopy.
1356 void qemu_savevm_state_pending(QEMUFile
*f
, uint64_t threshold_size
,
1357 uint64_t *res_precopy_only
,
1358 uint64_t *res_compatible
,
1359 uint64_t *res_postcopy_only
)
1363 *res_precopy_only
= 0;
1364 *res_compatible
= 0;
1365 *res_postcopy_only
= 0;
1368 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1369 if (!se
->ops
|| !se
->ops
->save_live_pending
) {
1372 if (se
->ops
&& se
->ops
->is_active
) {
1373 if (!se
->ops
->is_active(se
->opaque
)) {
1377 se
->ops
->save_live_pending(f
, se
->opaque
, threshold_size
,
1378 res_precopy_only
, res_compatible
,
1383 void qemu_savevm_state_cleanup(void)
1387 trace_savevm_state_cleanup();
1388 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1389 if (se
->ops
&& se
->ops
->save_cleanup
) {
1390 se
->ops
->save_cleanup(se
->opaque
);
1395 static int qemu_savevm_state(QEMUFile
*f
, Error
**errp
)
1398 MigrationState
*ms
= migrate_get_current();
1399 MigrationStatus status
;
1401 if (migration_is_setup_or_active(ms
->state
) ||
1402 ms
->state
== MIGRATION_STATUS_CANCELLING
||
1403 ms
->state
== MIGRATION_STATUS_COLO
) {
1404 error_setg(errp
, QERR_MIGRATION_ACTIVE
);
1408 if (migration_is_blocked(errp
)) {
1412 if (migrate_use_block()) {
1413 error_setg(errp
, "Block migration and snapshots are incompatible");
1418 ms
->to_dst_file
= f
;
1420 qemu_mutex_unlock_iothread();
1421 qemu_savevm_state_header(f
);
1422 qemu_savevm_state_setup(f
);
1423 qemu_mutex_lock_iothread();
1425 while (qemu_file_get_error(f
) == 0) {
1426 if (qemu_savevm_state_iterate(f
, false) > 0) {
1431 ret
= qemu_file_get_error(f
);
1433 qemu_savevm_state_complete_precopy(f
, false, false);
1434 ret
= qemu_file_get_error(f
);
1436 qemu_savevm_state_cleanup();
1438 error_setg_errno(errp
, -ret
, "Error while writing VM state");
1442 status
= MIGRATION_STATUS_FAILED
;
1444 status
= MIGRATION_STATUS_COMPLETED
;
1446 migrate_set_state(&ms
->state
, MIGRATION_STATUS_SETUP
, status
);
1448 /* f is outer parameter, it should not stay in global migration state after
1449 * this function finished */
1450 ms
->to_dst_file
= NULL
;
1455 void qemu_savevm_live_state(QEMUFile
*f
)
1457 /* save QEMU_VM_SECTION_END section */
1458 qemu_savevm_state_complete_precopy(f
, true, false);
1459 qemu_put_byte(f
, QEMU_VM_EOF
);
1462 int qemu_save_device_state(QEMUFile
*f
)
1466 if (!migration_in_colo_state()) {
1467 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
1468 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
1470 cpu_synchronize_all_states();
1472 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1478 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1481 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1485 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1487 ret
= vmstate_save(f
, se
, NULL
);
1492 save_section_footer(f
, se
);
1495 qemu_put_byte(f
, QEMU_VM_EOF
);
1497 return qemu_file_get_error(f
);
1500 static SaveStateEntry
*find_se(const char *idstr
, int instance_id
)
1504 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1505 if (!strcmp(se
->idstr
, idstr
) &&
1506 (instance_id
== se
->instance_id
||
1507 instance_id
== se
->alias_id
))
1509 /* Migrating from an older version? */
1510 if (strstr(se
->idstr
, idstr
) && se
->compat
) {
1511 if (!strcmp(se
->compat
->idstr
, idstr
) &&
1512 (instance_id
== se
->compat
->instance_id
||
1513 instance_id
== se
->alias_id
))
1520 enum LoadVMExitCodes
{
1521 /* Allow a command to quit all layers of nested loadvm loops */
1525 /* ------ incoming postcopy messages ------ */
1526 /* 'advise' arrives before any transfers just to tell us that a postcopy
1527 * *might* happen - it might be skipped if precopy transferred everything
1530 static int loadvm_postcopy_handle_advise(MigrationIncomingState
*mis
,
1533 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1534 uint64_t remote_pagesize_summary
, local_pagesize_summary
, remote_tps
;
1535 Error
*local_err
= NULL
;
1537 trace_loadvm_postcopy_handle_advise();
1538 if (ps
!= POSTCOPY_INCOMING_NONE
) {
1539 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps
);
1545 if (migrate_postcopy_ram()) {
1546 error_report("RAM postcopy is enabled but have 0 byte advise");
1551 if (!migrate_postcopy_ram()) {
1552 error_report("RAM postcopy is disabled but have 16 byte advise");
1557 error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len
);
1561 if (!postcopy_ram_supported_by_host(mis
)) {
1562 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
1566 remote_pagesize_summary
= qemu_get_be64(mis
->from_src_file
);
1567 local_pagesize_summary
= ram_pagesize_summary();
1569 if (remote_pagesize_summary
!= local_pagesize_summary
) {
1571 * This detects two potential causes of mismatch:
1572 * a) A mismatch in host page sizes
1573 * Some combinations of mismatch are probably possible but it gets
1574 * a bit more complicated. In particular we need to place whole
1575 * host pages on the dest at once, and we need to ensure that we
1576 * handle dirtying to make sure we never end up sending part of
1577 * a hostpage on it's own.
1578 * b) The use of different huge page sizes on source/destination
1579 * a more fine grain test is performed during RAM block migration
1580 * but this test here causes a nice early clear failure, and
1581 * also fails when passed to an older qemu that doesn't
1584 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
1586 remote_pagesize_summary
, local_pagesize_summary
);
1590 remote_tps
= qemu_get_be64(mis
->from_src_file
);
1591 if (remote_tps
!= qemu_target_page_size()) {
1593 * Again, some differences could be dealt with, but for now keep it
1596 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
1597 (int)remote_tps
, qemu_target_page_size());
1601 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE
, &local_err
)) {
1602 error_report_err(local_err
);
1606 if (ram_postcopy_incoming_init(mis
)) {
1610 postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1615 /* After postcopy we will be told to throw some pages away since they're
1616 * dirty and will have to be demand fetched. Must happen before CPU is
1618 * There can be 0..many of these messages, each encoding multiple pages.
1620 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState
*mis
,
1625 PostcopyState ps
= postcopy_state_get();
1627 trace_loadvm_postcopy_ram_handle_discard();
1630 case POSTCOPY_INCOMING_ADVISE
:
1632 tmp
= postcopy_ram_prepare_discard(mis
);
1638 case POSTCOPY_INCOMING_DISCARD
:
1639 /* Expected state */
1643 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
1647 /* We're expecting a
1649 * a RAM ID string (length byte, name, 0 term)
1650 * then at least 1 16 byte chunk
1652 if (len
< (1 + 1 + 1 + 1 + 2 * 8)) {
1653 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1657 tmp
= qemu_get_byte(mis
->from_src_file
);
1658 if (tmp
!= postcopy_ram_discard_version
) {
1659 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp
);
1663 if (!qemu_get_counted_string(mis
->from_src_file
, ramid
)) {
1664 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
1667 tmp
= qemu_get_byte(mis
->from_src_file
);
1669 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp
);
1673 len
-= 3 + strlen(ramid
);
1675 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1678 trace_loadvm_postcopy_ram_handle_discard_header(ramid
, len
);
1680 uint64_t start_addr
, block_length
;
1681 start_addr
= qemu_get_be64(mis
->from_src_file
);
1682 block_length
= qemu_get_be64(mis
->from_src_file
);
1685 int ret
= ram_discard_range(ramid
, start_addr
, block_length
);
1690 trace_loadvm_postcopy_ram_handle_discard_end();
1696 * Triggered by a postcopy_listen command; this thread takes over reading
1697 * the input stream, leaving the main thread free to carry on loading the rest
1698 * of the device state (from RAM).
1699 * (TODO:This could do with being in a postcopy file - but there again it's
1700 * just another input loop, not that postcopy specific)
1702 static void *postcopy_ram_listen_thread(void *opaque
)
1704 MigrationIncomingState
*mis
= migration_incoming_get_current();
1705 QEMUFile
*f
= mis
->from_src_file
;
1708 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
1709 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1710 qemu_sem_post(&mis
->listen_thread_sem
);
1711 trace_postcopy_ram_listen_thread_start();
1713 rcu_register_thread();
1715 * Because we're a thread and not a coroutine we can't yield
1716 * in qemu_file, and thus we must be blocking now.
1718 qemu_file_set_blocking(f
, true);
1719 load_res
= qemu_loadvm_state_main(f
, mis
);
1722 * This is tricky, but, mis->from_src_file can change after it
1723 * returns, when postcopy recovery happened. In the future, we may
1724 * want a wrapper for the QEMUFile handle.
1726 f
= mis
->from_src_file
;
1728 /* And non-blocking again so we don't block in any cleanup */
1729 qemu_file_set_blocking(f
, false);
1731 trace_postcopy_ram_listen_thread_exit();
1733 error_report("%s: loadvm failed: %d", __func__
, load_res
);
1734 qemu_file_set_error(f
, load_res
);
1735 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1736 MIGRATION_STATUS_FAILED
);
1739 * This looks good, but it's possible that the device loading in the
1740 * main thread hasn't finished yet, and so we might not be in 'RUN'
1741 * state yet; wait for the end of the main thread.
1743 qemu_event_wait(&mis
->main_thread_load_event
);
1745 postcopy_ram_incoming_cleanup(mis
);
1749 * If something went wrong then we have a bad state so exit;
1750 * depending how far we got it might be possible at this point
1751 * to leave the guest running and fire MCEs for pages that never
1752 * arrived as a desperate recovery step.
1754 rcu_unregister_thread();
1758 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1759 MIGRATION_STATUS_COMPLETED
);
1761 * If everything has worked fine, then the main thread has waited
1762 * for us to start, and we're the last use of the mis.
1763 * (If something broke then qemu will have to exit anyway since it's
1764 * got a bad migration state).
1766 migration_incoming_state_destroy();
1767 qemu_loadvm_state_cleanup();
1769 rcu_unregister_thread();
1770 mis
->have_listen_thread
= false;
1774 /* After this message we must be able to immediately receive postcopy data */
1775 static int loadvm_postcopy_handle_listen(MigrationIncomingState
*mis
)
1777 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_LISTENING
);
1778 trace_loadvm_postcopy_handle_listen();
1779 Error
*local_err
= NULL
;
1781 if (ps
!= POSTCOPY_INCOMING_ADVISE
&& ps
!= POSTCOPY_INCOMING_DISCARD
) {
1782 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps
);
1785 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
1787 * A rare case, we entered listen without having to do any discards,
1788 * so do the setup that's normally done at the time of the 1st discard.
1790 if (migrate_postcopy_ram()) {
1791 postcopy_ram_prepare_discard(mis
);
1796 * Sensitise RAM - can now generate requests for blocks that don't exist
1797 * However, at this point the CPU shouldn't be running, and the IO
1798 * shouldn't be doing anything yet so don't actually expect requests
1800 if (migrate_postcopy_ram()) {
1801 if (postcopy_ram_enable_notify(mis
)) {
1802 postcopy_ram_incoming_cleanup(mis
);
1807 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN
, &local_err
)) {
1808 error_report_err(local_err
);
1812 if (mis
->have_listen_thread
) {
1813 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
1817 mis
->have_listen_thread
= true;
1818 /* Start up the listening thread and wait for it to signal ready */
1819 qemu_sem_init(&mis
->listen_thread_sem
, 0);
1820 qemu_thread_create(&mis
->listen_thread
, "postcopy/listen",
1821 postcopy_ram_listen_thread
, NULL
,
1822 QEMU_THREAD_DETACHED
);
1823 qemu_sem_wait(&mis
->listen_thread_sem
);
1824 qemu_sem_destroy(&mis
->listen_thread_sem
);
1834 static void loadvm_postcopy_handle_run_bh(void *opaque
)
1836 Error
*local_err
= NULL
;
1837 HandleRunBhData
*data
= opaque
;
1838 MigrationIncomingState
*mis
= migration_incoming_get_current();
1840 /* TODO we should move all of this lot into postcopy_ram.c or a shared code
1843 cpu_synchronize_all_post_init();
1845 qemu_announce_self(&mis
->announce_timer
, migrate_announce_params());
1847 /* Make sure all file formats flush their mutable metadata.
1848 * If we get an error here, just don't restart the VM yet. */
1849 bdrv_invalidate_cache_all(&local_err
);
1851 error_report_err(local_err
);
1856 trace_loadvm_postcopy_handle_run_cpu_sync();
1857 cpu_synchronize_all_post_init();
1859 trace_loadvm_postcopy_handle_run_vmstart();
1861 dirty_bitmap_mig_before_vm_start();
1864 /* Hold onto your hats, starting the CPU */
1867 /* leave it paused and let management decide when to start the CPU */
1868 runstate_set(RUN_STATE_PAUSED
);
1871 qemu_bh_delete(data
->bh
);
1875 /* After all discards we can start running and asking for pages */
1876 static int loadvm_postcopy_handle_run(MigrationIncomingState
*mis
)
1878 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_RUNNING
);
1879 HandleRunBhData
*data
;
1881 trace_loadvm_postcopy_handle_run();
1882 if (ps
!= POSTCOPY_INCOMING_LISTENING
) {
1883 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps
);
1887 data
= g_new(HandleRunBhData
, 1);
1888 data
->bh
= qemu_bh_new(loadvm_postcopy_handle_run_bh
, data
);
1889 qemu_bh_schedule(data
->bh
);
1891 /* We need to finish reading the stream from the package
1892 * and also stop reading anything more from the stream that loaded the
1893 * package (since it's now being read by the listener thread).
1894 * LOADVM_QUIT will quit all the layers of nested loadvm loops.
1899 static int loadvm_postcopy_handle_resume(MigrationIncomingState
*mis
)
1901 if (mis
->state
!= MIGRATION_STATUS_POSTCOPY_RECOVER
) {
1902 error_report("%s: illegal resume received", __func__
);
1903 /* Don't fail the load, only for this. */
1908 * This means source VM is ready to resume the postcopy migration.
1909 * It's time to switch state and release the fault thread to
1910 * continue service page faults.
1912 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_RECOVER
,
1913 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1914 qemu_sem_post(&mis
->postcopy_pause_sem_fault
);
1916 trace_loadvm_postcopy_handle_resume();
1918 /* Tell source that "we are ready" */
1919 migrate_send_rp_resume_ack(mis
, MIGRATION_RESUME_ACK_VALUE
);
1925 * Immediately following this command is a blob of data containing an embedded
1926 * chunk of migration stream; read it and load it.
1928 * @mis: Incoming state
1929 * @length: Length of packaged data to read
1931 * Returns: Negative values on error
1934 static int loadvm_handle_cmd_packaged(MigrationIncomingState
*mis
)
1938 QIOChannelBuffer
*bioc
;
1940 length
= qemu_get_be32(mis
->from_src_file
);
1941 trace_loadvm_handle_cmd_packaged(length
);
1943 if (length
> MAX_VM_CMD_PACKAGED_SIZE
) {
1944 error_report("Unreasonably large packaged state: %zu", length
);
1948 bioc
= qio_channel_buffer_new(length
);
1949 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-loadvm-buffer");
1950 ret
= qemu_get_buffer(mis
->from_src_file
,
1953 if (ret
!= length
) {
1954 object_unref(OBJECT(bioc
));
1955 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
1957 return (ret
< 0) ? ret
: -EAGAIN
;
1959 bioc
->usage
+= length
;
1960 trace_loadvm_handle_cmd_packaged_received(ret
);
1962 QEMUFile
*packf
= qemu_fopen_channel_input(QIO_CHANNEL(bioc
));
1964 ret
= qemu_loadvm_state_main(packf
, mis
);
1965 trace_loadvm_handle_cmd_packaged_main(ret
);
1967 object_unref(OBJECT(bioc
));
1973 * Handle request that source requests for recved_bitmap on
1974 * destination. Payload format:
1976 * len (1 byte) + ramblock_name (<255 bytes)
1978 static int loadvm_handle_recv_bitmap(MigrationIncomingState
*mis
,
1981 QEMUFile
*file
= mis
->from_src_file
;
1983 char block_name
[256];
1986 cnt
= qemu_get_counted_string(file
, block_name
);
1988 error_report("%s: failed to read block name", __func__
);
1992 /* Validate before using the data */
1993 if (qemu_file_get_error(file
)) {
1994 return qemu_file_get_error(file
);
1997 if (len
!= cnt
+ 1) {
1998 error_report("%s: invalid payload length (%d)", __func__
, len
);
2002 rb
= qemu_ram_block_by_name(block_name
);
2004 error_report("%s: block '%s' not found", __func__
, block_name
);
2008 migrate_send_rp_recv_bitmap(mis
, block_name
);
2010 trace_loadvm_handle_recv_bitmap(block_name
);
2015 static int loadvm_process_enable_colo(MigrationIncomingState
*mis
)
2017 migration_incoming_enable_colo();
2018 return colo_init_ram_cache();
2022 * Process an incoming 'QEMU_VM_COMMAND'
2023 * 0 just a normal return
2024 * LOADVM_QUIT All good, but exit the loop
2027 static int loadvm_process_command(QEMUFile
*f
)
2029 MigrationIncomingState
*mis
= migration_incoming_get_current();
2034 cmd
= qemu_get_be16(f
);
2035 len
= qemu_get_be16(f
);
2037 /* Check validity before continue processing of cmds */
2038 if (qemu_file_get_error(f
)) {
2039 return qemu_file_get_error(f
);
2042 trace_loadvm_process_command(cmd
, len
);
2043 if (cmd
>= MIG_CMD_MAX
|| cmd
== MIG_CMD_INVALID
) {
2044 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd
, len
);
2048 if (mig_cmd_args
[cmd
].len
!= -1 && mig_cmd_args
[cmd
].len
!= len
) {
2049 error_report("%s received with bad length - expecting %zu, got %d",
2050 mig_cmd_args
[cmd
].name
,
2051 (size_t)mig_cmd_args
[cmd
].len
, len
);
2056 case MIG_CMD_OPEN_RETURN_PATH
:
2057 if (mis
->to_src_file
) {
2058 error_report("CMD_OPEN_RETURN_PATH called when RP already open");
2059 /* Not really a problem, so don't give up */
2062 mis
->to_src_file
= qemu_file_get_return_path(f
);
2063 if (!mis
->to_src_file
) {
2064 error_report("CMD_OPEN_RETURN_PATH failed");
2070 tmp32
= qemu_get_be32(f
);
2071 trace_loadvm_process_command_ping(tmp32
);
2072 if (!mis
->to_src_file
) {
2073 error_report("CMD_PING (0x%x) received with no return path",
2077 migrate_send_rp_pong(mis
, tmp32
);
2080 case MIG_CMD_PACKAGED
:
2081 return loadvm_handle_cmd_packaged(mis
);
2083 case MIG_CMD_POSTCOPY_ADVISE
:
2084 return loadvm_postcopy_handle_advise(mis
, len
);
2086 case MIG_CMD_POSTCOPY_LISTEN
:
2087 return loadvm_postcopy_handle_listen(mis
);
2089 case MIG_CMD_POSTCOPY_RUN
:
2090 return loadvm_postcopy_handle_run(mis
);
2092 case MIG_CMD_POSTCOPY_RAM_DISCARD
:
2093 return loadvm_postcopy_ram_handle_discard(mis
, len
);
2095 case MIG_CMD_POSTCOPY_RESUME
:
2096 return loadvm_postcopy_handle_resume(mis
);
2098 case MIG_CMD_RECV_BITMAP
:
2099 return loadvm_handle_recv_bitmap(mis
, len
);
2101 case MIG_CMD_ENABLE_COLO
:
2102 return loadvm_process_enable_colo(mis
);
2109 * Read a footer off the wire and check that it matches the expected section
2111 * Returns: true if the footer was good
2112 * false if there is a problem (and calls error_report to say why)
2114 static bool check_section_footer(QEMUFile
*f
, SaveStateEntry
*se
)
2118 uint32_t read_section_id
;
2120 if (!migrate_get_current()->send_section_footer
) {
2121 /* No footer to check */
2125 read_mark
= qemu_get_byte(f
);
2127 ret
= qemu_file_get_error(f
);
2129 error_report("%s: Read section footer failed: %d",
2134 if (read_mark
!= QEMU_VM_SECTION_FOOTER
) {
2135 error_report("Missing section footer for %s", se
->idstr
);
2139 read_section_id
= qemu_get_be32(f
);
2140 if (read_section_id
!= se
->load_section_id
) {
2141 error_report("Mismatched section id in footer for %s -"
2142 " read 0x%x expected 0x%x",
2143 se
->idstr
, read_section_id
, se
->load_section_id
);
2152 qemu_loadvm_section_start_full(QEMUFile
*f
, MigrationIncomingState
*mis
)
2154 uint32_t instance_id
, version_id
, section_id
;
2159 /* Read section start */
2160 section_id
= qemu_get_be32(f
);
2161 if (!qemu_get_counted_string(f
, idstr
)) {
2162 error_report("Unable to read ID string for section %u",
2166 instance_id
= qemu_get_be32(f
);
2167 version_id
= qemu_get_be32(f
);
2169 ret
= qemu_file_get_error(f
);
2171 error_report("%s: Failed to read instance/version ID: %d",
2176 trace_qemu_loadvm_state_section_startfull(section_id
, idstr
,
2177 instance_id
, version_id
);
2178 /* Find savevm section */
2179 se
= find_se(idstr
, instance_id
);
2181 error_report("Unknown savevm section or instance '%s' %d. "
2182 "Make sure that your current VM setup matches your "
2183 "saved VM setup, including any hotplugged devices",
2184 idstr
, instance_id
);
2188 /* Validate version */
2189 if (version_id
> se
->version_id
) {
2190 error_report("savevm: unsupported version %d for '%s' v%d",
2191 version_id
, idstr
, se
->version_id
);
2194 se
->load_version_id
= version_id
;
2195 se
->load_section_id
= section_id
;
2197 /* Validate if it is a device's state */
2198 if (xen_enabled() && se
->is_ram
) {
2199 error_report("loadvm: %s RAM loading not allowed on Xen", idstr
);
2203 ret
= vmstate_load(f
, se
);
2205 error_report("error while loading state for instance 0x%x of"
2206 " device '%s'", instance_id
, idstr
);
2209 if (!check_section_footer(f
, se
)) {
2217 qemu_loadvm_section_part_end(QEMUFile
*f
, MigrationIncomingState
*mis
)
2219 uint32_t section_id
;
2223 section_id
= qemu_get_be32(f
);
2225 ret
= qemu_file_get_error(f
);
2227 error_report("%s: Failed to read section ID: %d",
2232 trace_qemu_loadvm_state_section_partend(section_id
);
2233 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
2234 if (se
->load_section_id
== section_id
) {
2239 error_report("Unknown savevm section %d", section_id
);
2243 ret
= vmstate_load(f
, se
);
2245 error_report("error while loading state section id %d(%s)",
2246 section_id
, se
->idstr
);
2249 if (!check_section_footer(f
, se
)) {
2256 static int qemu_loadvm_state_setup(QEMUFile
*f
)
2261 trace_loadvm_state_setup();
2262 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
2263 if (!se
->ops
|| !se
->ops
->load_setup
) {
2266 if (se
->ops
&& se
->ops
->is_active
) {
2267 if (!se
->ops
->is_active(se
->opaque
)) {
2272 ret
= se
->ops
->load_setup(f
, se
->opaque
);
2274 qemu_file_set_error(f
, ret
);
2275 error_report("Load state of device %s failed", se
->idstr
);
2282 void qemu_loadvm_state_cleanup(void)
2286 trace_loadvm_state_cleanup();
2287 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
2288 if (se
->ops
&& se
->ops
->load_cleanup
) {
2289 se
->ops
->load_cleanup(se
->opaque
);
2294 /* Return true if we should continue the migration, or false. */
2295 static bool postcopy_pause_incoming(MigrationIncomingState
*mis
)
2297 trace_postcopy_pause_incoming();
2299 /* Clear the triggered bit to allow one recovery */
2300 mis
->postcopy_recover_triggered
= false;
2302 assert(mis
->from_src_file
);
2303 qemu_file_shutdown(mis
->from_src_file
);
2304 qemu_fclose(mis
->from_src_file
);
2305 mis
->from_src_file
= NULL
;
2307 assert(mis
->to_src_file
);
2308 qemu_file_shutdown(mis
->to_src_file
);
2309 qemu_mutex_lock(&mis
->rp_mutex
);
2310 qemu_fclose(mis
->to_src_file
);
2311 mis
->to_src_file
= NULL
;
2312 qemu_mutex_unlock(&mis
->rp_mutex
);
2314 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
2315 MIGRATION_STATUS_POSTCOPY_PAUSED
);
2317 /* Notify the fault thread for the invalidated file handle */
2318 postcopy_fault_thread_notify(mis
);
2320 error_report("Detected IO failure for postcopy. "
2321 "Migration paused.");
2323 while (mis
->state
== MIGRATION_STATUS_POSTCOPY_PAUSED
) {
2324 qemu_sem_wait(&mis
->postcopy_pause_sem_dst
);
2327 trace_postcopy_pause_incoming_continued();
2332 int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
)
2334 uint8_t section_type
;
2339 section_type
= qemu_get_byte(f
);
2341 if (qemu_file_get_error(f
)) {
2342 ret
= qemu_file_get_error(f
);
2346 trace_qemu_loadvm_state_section(section_type
);
2347 switch (section_type
) {
2348 case QEMU_VM_SECTION_START
:
2349 case QEMU_VM_SECTION_FULL
:
2350 ret
= qemu_loadvm_section_start_full(f
, mis
);
2355 case QEMU_VM_SECTION_PART
:
2356 case QEMU_VM_SECTION_END
:
2357 ret
= qemu_loadvm_section_part_end(f
, mis
);
2362 case QEMU_VM_COMMAND
:
2363 ret
= loadvm_process_command(f
);
2364 trace_qemu_loadvm_state_section_command(ret
);
2365 if ((ret
< 0) || (ret
& LOADVM_QUIT
)) {
2370 /* This is the end of migration */
2373 error_report("Unknown savevm section type %d", section_type
);
2381 qemu_file_set_error(f
, ret
);
2384 * If we are during an active postcopy, then we pause instead
2385 * of bail out to at least keep the VM's dirty data. Note
2386 * that POSTCOPY_INCOMING_LISTENING stage is still not enough,
2387 * during which we're still receiving device states and we
2388 * still haven't yet started the VM on destination.
2390 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING
&&
2391 postcopy_pause_incoming(mis
)) {
2392 /* Reset f to point to the newly created channel */
2393 f
= mis
->from_src_file
;
2400 int qemu_loadvm_state(QEMUFile
*f
)
2402 MigrationIncomingState
*mis
= migration_incoming_get_current();
2403 Error
*local_err
= NULL
;
2407 if (qemu_savevm_state_blocked(&local_err
)) {
2408 error_report_err(local_err
);
2412 v
= qemu_get_be32(f
);
2413 if (v
!= QEMU_VM_FILE_MAGIC
) {
2414 error_report("Not a migration stream");
2418 v
= qemu_get_be32(f
);
2419 if (v
== QEMU_VM_FILE_VERSION_COMPAT
) {
2420 error_report("SaveVM v2 format is obsolete and don't work anymore");
2423 if (v
!= QEMU_VM_FILE_VERSION
) {
2424 error_report("Unsupported migration stream version");
2428 if (qemu_loadvm_state_setup(f
) != 0) {
2432 if (migrate_get_current()->send_configuration
) {
2433 if (qemu_get_byte(f
) != QEMU_VM_CONFIGURATION
) {
2434 error_report("Configuration section missing");
2435 qemu_loadvm_state_cleanup();
2438 ret
= vmstate_load_state(f
, &vmstate_configuration
, &savevm_state
, 0);
2441 qemu_loadvm_state_cleanup();
2446 cpu_synchronize_all_pre_loadvm();
2448 ret
= qemu_loadvm_state_main(f
, mis
);
2449 qemu_event_set(&mis
->main_thread_load_event
);
2451 trace_qemu_loadvm_state_post_main(ret
);
2453 if (mis
->have_listen_thread
) {
2454 /* Listen thread still going, can't clean up yet */
2459 ret
= qemu_file_get_error(f
);
2463 * Try to read in the VMDESC section as well, so that dumping tools that
2464 * intercept our migration stream have the chance to see it.
2467 /* We've got to be careful; if we don't read the data and just shut the fd
2468 * then the sender can error if we close while it's still sending.
2469 * We also mustn't read data that isn't there; some transports (RDMA)
2470 * will stall waiting for that data when the source has already closed.
2472 if (ret
== 0 && should_send_vmdesc()) {
2475 uint8_t section_type
= qemu_get_byte(f
);
2477 if (section_type
!= QEMU_VM_VMDESCRIPTION
) {
2478 error_report("Expected vmdescription section, but got %d",
2481 * It doesn't seem worth failing at this point since
2482 * we apparently have an otherwise valid VM state
2485 buf
= g_malloc(0x1000);
2486 size
= qemu_get_be32(f
);
2489 uint32_t read_chunk
= MIN(size
, 0x1000);
2490 qemu_get_buffer(f
, buf
, read_chunk
);
2497 qemu_loadvm_state_cleanup();
2498 cpu_synchronize_all_post_init();
2503 int qemu_load_device_state(QEMUFile
*f
)
2505 MigrationIncomingState
*mis
= migration_incoming_get_current();
2508 /* Load QEMU_VM_SECTION_FULL section */
2509 ret
= qemu_loadvm_state_main(f
, mis
);
2511 error_report("Failed to load device state: %d", ret
);
2515 cpu_synchronize_all_post_init();
2519 int save_snapshot(const char *name
, Error
**errp
)
2521 BlockDriverState
*bs
, *bs1
;
2522 QEMUSnapshotInfo sn1
, *sn
= &sn1
, old_sn1
, *old_sn
= &old_sn1
;
2525 int saved_vm_running
;
2526 uint64_t vm_state_size
;
2529 AioContext
*aio_context
;
2531 if (migration_is_blocked(errp
)) {
2535 if (!replay_can_snapshot()) {
2536 error_setg(errp
, "Record/replay does not allow making snapshot "
2537 "right now. Try once more later.");
2541 if (!bdrv_all_can_snapshot(&bs
)) {
2542 error_setg(errp
, "Device '%s' is writable but does not support "
2543 "snapshots", bdrv_get_device_name(bs
));
2547 /* Delete old snapshots of the same name */
2549 ret
= bdrv_all_delete_snapshot(name
, &bs1
, errp
);
2551 error_prepend(errp
, "Error while deleting snapshot on device "
2552 "'%s': ", bdrv_get_device_name(bs1
));
2557 bs
= bdrv_all_find_vmstate_bs();
2559 error_setg(errp
, "No block device can accept snapshots");
2562 aio_context
= bdrv_get_aio_context(bs
);
2564 saved_vm_running
= runstate_is_running();
2566 ret
= global_state_store();
2568 error_setg(errp
, "Error saving global state");
2571 vm_stop(RUN_STATE_SAVE_VM
);
2573 bdrv_drain_all_begin();
2575 aio_context_acquire(aio_context
);
2577 memset(sn
, 0, sizeof(*sn
));
2579 /* fill auxiliary fields */
2580 qemu_gettimeofday(&tv
);
2581 sn
->date_sec
= tv
.tv_sec
;
2582 sn
->date_nsec
= tv
.tv_usec
* 1000;
2583 sn
->vm_clock_nsec
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
2586 ret
= bdrv_snapshot_find(bs
, old_sn
, name
);
2588 pstrcpy(sn
->name
, sizeof(sn
->name
), old_sn
->name
);
2589 pstrcpy(sn
->id_str
, sizeof(sn
->id_str
), old_sn
->id_str
);
2591 pstrcpy(sn
->name
, sizeof(sn
->name
), name
);
2594 /* cast below needed for OpenBSD where tv_sec is still 'long' */
2595 localtime_r((const time_t *)&tv
.tv_sec
, &tm
);
2596 strftime(sn
->name
, sizeof(sn
->name
), "vm-%Y%m%d%H%M%S", &tm
);
2599 /* save the VM state */
2600 f
= qemu_fopen_bdrv(bs
, 1);
2602 error_setg(errp
, "Could not open VM state file");
2605 ret
= qemu_savevm_state(f
, errp
);
2606 vm_state_size
= qemu_ftell(f
);
2612 /* The bdrv_all_create_snapshot() call that follows acquires the AioContext
2613 * for itself. BDRV_POLL_WHILE() does not support nested locking because
2614 * it only releases the lock once. Therefore synchronous I/O will deadlock
2615 * unless we release the AioContext before bdrv_all_create_snapshot().
2617 aio_context_release(aio_context
);
2620 ret
= bdrv_all_create_snapshot(sn
, bs
, vm_state_size
, &bs
);
2622 error_setg(errp
, "Error while creating snapshot on '%s'",
2623 bdrv_get_device_name(bs
));
2631 aio_context_release(aio_context
);
2634 bdrv_drain_all_end();
2636 if (saved_vm_running
) {
2642 void qmp_xen_save_devices_state(const char *filename
, bool has_live
, bool live
,
2646 QIOChannelFile
*ioc
;
2647 int saved_vm_running
;
2651 /* live default to true so old version of Xen tool stack can have a
2652 * successfull live migration */
2656 saved_vm_running
= runstate_is_running();
2657 vm_stop(RUN_STATE_SAVE_VM
);
2658 global_state_store_running();
2660 ioc
= qio_channel_file_new_path(filename
, O_WRONLY
| O_CREAT
, 0660, errp
);
2664 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-save-state");
2665 f
= qemu_fopen_channel_output(QIO_CHANNEL(ioc
));
2666 object_unref(OBJECT(ioc
));
2667 ret
= qemu_save_device_state(f
);
2668 if (ret
< 0 || qemu_fclose(f
) < 0) {
2669 error_setg(errp
, QERR_IO_ERROR
);
2671 /* libxl calls the QMP command "stop" before calling
2672 * "xen-save-devices-state" and in case of migration failure, libxl
2673 * would call "cont".
2674 * So call bdrv_inactivate_all (release locks) here to let the other
2675 * side of the migration take controle of the images.
2677 if (live
&& !saved_vm_running
) {
2678 ret
= bdrv_inactivate_all();
2680 error_setg(errp
, "%s: bdrv_inactivate_all() failed (%d)",
2687 if (saved_vm_running
) {
2692 void qmp_xen_load_devices_state(const char *filename
, Error
**errp
)
2695 QIOChannelFile
*ioc
;
2698 /* Guest must be paused before loading the device state; the RAM state
2699 * will already have been loaded by xc
2701 if (runstate_is_running()) {
2702 error_setg(errp
, "Cannot update device state while vm is running");
2705 vm_stop(RUN_STATE_RESTORE_VM
);
2707 ioc
= qio_channel_file_new_path(filename
, O_RDONLY
| O_BINARY
, 0, errp
);
2711 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-load-state");
2712 f
= qemu_fopen_channel_input(QIO_CHANNEL(ioc
));
2713 object_unref(OBJECT(ioc
));
2715 ret
= qemu_loadvm_state(f
);
2718 error_setg(errp
, QERR_IO_ERROR
);
2720 migration_incoming_state_destroy();
2723 int load_snapshot(const char *name
, Error
**errp
)
2725 BlockDriverState
*bs
, *bs_vm_state
;
2726 QEMUSnapshotInfo sn
;
2729 AioContext
*aio_context
;
2730 MigrationIncomingState
*mis
= migration_incoming_get_current();
2732 if (!replay_can_snapshot()) {
2733 error_setg(errp
, "Record/replay does not allow loading snapshot "
2734 "right now. Try once more later.");
2738 if (!bdrv_all_can_snapshot(&bs
)) {
2740 "Device '%s' is writable but does not support snapshots",
2741 bdrv_get_device_name(bs
));
2744 ret
= bdrv_all_find_snapshot(name
, &bs
);
2747 "Device '%s' does not have the requested snapshot '%s'",
2748 bdrv_get_device_name(bs
), name
);
2752 bs_vm_state
= bdrv_all_find_vmstate_bs();
2754 error_setg(errp
, "No block device supports snapshots");
2757 aio_context
= bdrv_get_aio_context(bs_vm_state
);
2759 /* Don't even try to load empty VM states */
2760 aio_context_acquire(aio_context
);
2761 ret
= bdrv_snapshot_find(bs_vm_state
, &sn
, name
);
2762 aio_context_release(aio_context
);
2765 } else if (sn
.vm_state_size
== 0) {
2766 error_setg(errp
, "This is a disk-only snapshot. Revert to it "
2767 " offline using qemu-img");
2771 /* Flush all IO requests so they don't interfere with the new state. */
2772 bdrv_drain_all_begin();
2774 ret
= bdrv_all_goto_snapshot(name
, &bs
, errp
);
2776 error_prepend(errp
, "Could not load snapshot '%s' on '%s': ",
2777 name
, bdrv_get_device_name(bs
));
2781 /* restore the VM state */
2782 f
= qemu_fopen_bdrv(bs_vm_state
, 0);
2784 error_setg(errp
, "Could not open VM state file");
2789 qemu_system_reset(SHUTDOWN_CAUSE_NONE
);
2790 mis
->from_src_file
= f
;
2792 aio_context_acquire(aio_context
);
2793 ret
= qemu_loadvm_state(f
);
2794 migration_incoming_state_destroy();
2795 aio_context_release(aio_context
);
2797 bdrv_drain_all_end();
2800 error_setg(errp
, "Error %d while loading VM state", ret
);
2807 bdrv_drain_all_end();
2811 void vmstate_register_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2813 qemu_ram_set_idstr(mr
->ram_block
,
2814 memory_region_name(mr
), dev
);
2815 qemu_ram_set_migratable(mr
->ram_block
);
2818 void vmstate_unregister_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2820 qemu_ram_unset_idstr(mr
->ram_block
);
2821 qemu_ram_unset_migratable(mr
->ram_block
);
2824 void vmstate_register_ram_global(MemoryRegion
*mr
)
2826 vmstate_register_ram(mr
, NULL
);
2829 bool vmstate_check_only_migratable(const VMStateDescription
*vmsd
)
2831 /* check needed if --only-migratable is specified */
2832 if (!migrate_get_current()->only_migratable
) {
2836 return !(vmsd
&& vmsd
->unmigratable
);