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"
33 #include "hw/xen/xen.h"
35 #include "sysemu/sysemu.h"
36 #include "qemu/timer.h"
37 #include "migration/migration.h"
38 #include "qemu-file-channel.h"
40 #include "postcopy-ram.h"
41 #include "qapi/qmp/qerror.h"
42 #include "qemu/error-report.h"
43 #include "qemu/queue.h"
44 #include "sysemu/cpus.h"
45 #include "exec/memory.h"
46 #include "exec/target_page.h"
47 #include "qmp-commands.h"
49 #include "qemu/bitops.h"
51 #include "block/snapshot.h"
52 #include "qemu/cutils.h"
53 #include "io/channel-buffer.h"
54 #include "io/channel-file.h"
57 #define ETH_P_RARP 0x8035
59 #define ARP_HTYPE_ETH 0x0001
60 #define ARP_PTYPE_IP 0x0800
61 #define ARP_OP_REQUEST_REV 0x3
63 const unsigned int postcopy_ram_discard_version
= 0;
65 static bool skip_section_footers
;
67 /* Subcommands for QEMU_VM_COMMAND */
69 MIG_CMD_INVALID
= 0, /* Must be 0 */
70 MIG_CMD_OPEN_RETURN_PATH
, /* Tell the dest to open the Return path */
71 MIG_CMD_PING
, /* Request a PONG on the RP */
73 MIG_CMD_POSTCOPY_ADVISE
, /* Prior to any page transfers, just
74 warn we might want to do PC */
75 MIG_CMD_POSTCOPY_LISTEN
, /* Start listening for incoming
76 pages as it's running. */
77 MIG_CMD_POSTCOPY_RUN
, /* Start execution */
79 MIG_CMD_POSTCOPY_RAM_DISCARD
, /* A list of pages to discard that
80 were previously sent during
81 precopy but are dirty. */
82 MIG_CMD_PACKAGED
, /* Send a wrapped stream within this stream */
86 #define MAX_VM_CMD_PACKAGED_SIZE (1ul << 24)
87 static struct mig_cmd_args
{
88 ssize_t len
; /* -1 = variable */
91 [MIG_CMD_INVALID
] = { .len
= -1, .name
= "INVALID" },
92 [MIG_CMD_OPEN_RETURN_PATH
] = { .len
= 0, .name
= "OPEN_RETURN_PATH" },
93 [MIG_CMD_PING
] = { .len
= sizeof(uint32_t), .name
= "PING" },
94 [MIG_CMD_POSTCOPY_ADVISE
] = { .len
= 16, .name
= "POSTCOPY_ADVISE" },
95 [MIG_CMD_POSTCOPY_LISTEN
] = { .len
= 0, .name
= "POSTCOPY_LISTEN" },
96 [MIG_CMD_POSTCOPY_RUN
] = { .len
= 0, .name
= "POSTCOPY_RUN" },
97 [MIG_CMD_POSTCOPY_RAM_DISCARD
] = {
98 .len
= -1, .name
= "POSTCOPY_RAM_DISCARD" },
99 [MIG_CMD_PACKAGED
] = { .len
= 4, .name
= "PACKAGED" },
100 [MIG_CMD_MAX
] = { .len
= -1, .name
= "MAX" },
103 static int announce_self_create(uint8_t *buf
,
106 /* Ethernet header. */
107 memset(buf
, 0xff, 6); /* destination MAC addr */
108 memcpy(buf
+ 6, mac_addr
, 6); /* source MAC addr */
109 *(uint16_t *)(buf
+ 12) = htons(ETH_P_RARP
); /* ethertype */
112 *(uint16_t *)(buf
+ 14) = htons(ARP_HTYPE_ETH
); /* hardware addr space */
113 *(uint16_t *)(buf
+ 16) = htons(ARP_PTYPE_IP
); /* protocol addr space */
114 *(buf
+ 18) = 6; /* hardware addr length (ethernet) */
115 *(buf
+ 19) = 4; /* protocol addr length (IPv4) */
116 *(uint16_t *)(buf
+ 20) = htons(ARP_OP_REQUEST_REV
); /* opcode */
117 memcpy(buf
+ 22, mac_addr
, 6); /* source hw addr */
118 memset(buf
+ 28, 0x00, 4); /* source protocol addr */
119 memcpy(buf
+ 32, mac_addr
, 6); /* target hw addr */
120 memset(buf
+ 38, 0x00, 4); /* target protocol addr */
122 /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
123 memset(buf
+ 42, 0x00, 18);
125 return 60; /* len (FCS will be added by hardware) */
128 static void qemu_announce_self_iter(NICState
*nic
, void *opaque
)
133 trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic
->conf
->macaddr
));
134 len
= announce_self_create(buf
, nic
->conf
->macaddr
.a
);
136 qemu_send_packet_raw(qemu_get_queue(nic
), buf
, len
);
140 static void qemu_announce_self_once(void *opaque
)
142 static int count
= SELF_ANNOUNCE_ROUNDS
;
143 QEMUTimer
*timer
= *(QEMUTimer
**)opaque
;
145 qemu_foreach_nic(qemu_announce_self_iter
, NULL
);
148 /* delay 50ms, 150ms, 250ms, ... */
149 timer_mod(timer
, qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) +
150 self_announce_delay(count
));
157 void qemu_announce_self(void)
159 static QEMUTimer
*timer
;
160 timer
= timer_new_ms(QEMU_CLOCK_REALTIME
, qemu_announce_self_once
, &timer
);
161 qemu_announce_self_once(&timer
);
164 /***********************************************************/
165 /* savevm/loadvm support */
167 static ssize_t
block_writev_buffer(void *opaque
, struct iovec
*iov
, int iovcnt
,
173 qemu_iovec_init_external(&qiov
, iov
, iovcnt
);
174 ret
= bdrv_writev_vmstate(opaque
, &qiov
, pos
);
182 static ssize_t
block_get_buffer(void *opaque
, uint8_t *buf
, int64_t pos
,
185 return bdrv_load_vmstate(opaque
, buf
, pos
, size
);
188 static int bdrv_fclose(void *opaque
)
190 return bdrv_flush(opaque
);
193 static const QEMUFileOps bdrv_read_ops
= {
194 .get_buffer
= block_get_buffer
,
198 static const QEMUFileOps bdrv_write_ops
= {
199 .writev_buffer
= block_writev_buffer
,
203 static QEMUFile
*qemu_fopen_bdrv(BlockDriverState
*bs
, int is_writable
)
206 return qemu_fopen_ops(bs
, &bdrv_write_ops
);
208 return qemu_fopen_ops(bs
, &bdrv_read_ops
);
212 /* QEMUFile timer support.
213 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
216 void timer_put(QEMUFile
*f
, QEMUTimer
*ts
)
218 uint64_t expire_time
;
220 expire_time
= timer_expire_time_ns(ts
);
221 qemu_put_be64(f
, expire_time
);
224 void timer_get(QEMUFile
*f
, QEMUTimer
*ts
)
226 uint64_t expire_time
;
228 expire_time
= qemu_get_be64(f
);
229 if (expire_time
!= -1) {
230 timer_mod_ns(ts
, expire_time
);
237 /* VMState timer support.
238 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
241 static int get_timer(QEMUFile
*f
, void *pv
, size_t size
, VMStateField
*field
)
248 static int put_timer(QEMUFile
*f
, void *pv
, size_t size
, VMStateField
*field
,
257 const VMStateInfo vmstate_info_timer
= {
264 typedef struct CompatEntry
{
269 typedef struct SaveStateEntry
{
270 QTAILQ_ENTRY(SaveStateEntry
) entry
;
277 const VMStateDescription
*vmsd
;
283 typedef struct SaveState
{
284 QTAILQ_HEAD(, SaveStateEntry
) handlers
;
285 int global_section_id
;
286 bool skip_configuration
;
289 uint32_t target_page_bits
;
292 static SaveState savevm_state
= {
293 .handlers
= QTAILQ_HEAD_INITIALIZER(savevm_state
.handlers
),
294 .global_section_id
= 0,
295 .skip_configuration
= false,
298 void savevm_skip_configuration(void)
300 savevm_state
.skip_configuration
= true;
304 static void configuration_pre_save(void *opaque
)
306 SaveState
*state
= opaque
;
307 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
309 state
->len
= strlen(current_name
);
310 state
->name
= current_name
;
311 state
->target_page_bits
= qemu_target_page_bits();
314 static int configuration_pre_load(void *opaque
)
316 SaveState
*state
= opaque
;
318 /* If there is no target-page-bits subsection it means the source
319 * predates the variable-target-page-bits support and is using the
320 * minimum possible value for this CPU.
322 state
->target_page_bits
= qemu_target_page_bits_min();
326 static int configuration_post_load(void *opaque
, int version_id
)
328 SaveState
*state
= opaque
;
329 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
331 if (strncmp(state
->name
, current_name
, state
->len
) != 0) {
332 error_report("Machine type received is '%.*s' and local is '%s'",
333 (int) state
->len
, state
->name
, current_name
);
337 if (state
->target_page_bits
!= qemu_target_page_bits()) {
338 error_report("Received TARGET_PAGE_BITS is %d but local is %d",
339 state
->target_page_bits
, qemu_target_page_bits());
346 /* The target-page-bits subsection is present only if the
347 * target page size is not the same as the default (ie the
348 * minimum page size for a variable-page-size guest CPU).
349 * If it is present then it contains the actual target page
350 * bits for the machine, and migration will fail if the
351 * two ends don't agree about it.
353 static bool vmstate_target_page_bits_needed(void *opaque
)
355 return qemu_target_page_bits()
356 > qemu_target_page_bits_min();
359 static const VMStateDescription vmstate_target_page_bits
= {
360 .name
= "configuration/target-page-bits",
362 .minimum_version_id
= 1,
363 .needed
= vmstate_target_page_bits_needed
,
364 .fields
= (VMStateField
[]) {
365 VMSTATE_UINT32(target_page_bits
, SaveState
),
366 VMSTATE_END_OF_LIST()
370 static const VMStateDescription vmstate_configuration
= {
371 .name
= "configuration",
373 .pre_load
= configuration_pre_load
,
374 .post_load
= configuration_post_load
,
375 .pre_save
= configuration_pre_save
,
376 .fields
= (VMStateField
[]) {
377 VMSTATE_UINT32(len
, SaveState
),
378 VMSTATE_VBUFFER_ALLOC_UINT32(name
, SaveState
, 0, NULL
, len
),
379 VMSTATE_END_OF_LIST()
381 .subsections
= (const VMStateDescription
*[]) {
382 &vmstate_target_page_bits
,
387 static void dump_vmstate_vmsd(FILE *out_file
,
388 const VMStateDescription
*vmsd
, int indent
,
391 static void dump_vmstate_vmsf(FILE *out_file
, const VMStateField
*field
,
394 fprintf(out_file
, "%*s{\n", indent
, "");
396 fprintf(out_file
, "%*s\"field\": \"%s\",\n", indent
, "", field
->name
);
397 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
399 fprintf(out_file
, "%*s\"field_exists\": %s,\n", indent
, "",
400 field
->field_exists
? "true" : "false");
401 fprintf(out_file
, "%*s\"size\": %zu", indent
, "", field
->size
);
402 if (field
->vmsd
!= NULL
) {
403 fprintf(out_file
, ",\n");
404 dump_vmstate_vmsd(out_file
, field
->vmsd
, indent
, false);
406 fprintf(out_file
, "\n%*s}", indent
- 2, "");
409 static void dump_vmstate_vmss(FILE *out_file
,
410 const VMStateDescription
**subsection
,
413 if (*subsection
!= NULL
) {
414 dump_vmstate_vmsd(out_file
, *subsection
, indent
, true);
418 static void dump_vmstate_vmsd(FILE *out_file
,
419 const VMStateDescription
*vmsd
, int indent
,
423 fprintf(out_file
, "%*s{\n", indent
, "");
425 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", "Description");
428 fprintf(out_file
, "%*s\"name\": \"%s\",\n", indent
, "", vmsd
->name
);
429 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
431 fprintf(out_file
, "%*s\"minimum_version_id\": %d", indent
, "",
432 vmsd
->minimum_version_id
);
433 if (vmsd
->fields
!= NULL
) {
434 const VMStateField
*field
= vmsd
->fields
;
437 fprintf(out_file
, ",\n%*s\"Fields\": [\n", indent
, "");
439 while (field
->name
!= NULL
) {
440 if (field
->flags
& VMS_MUST_EXIST
) {
441 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
446 fprintf(out_file
, ",\n");
448 dump_vmstate_vmsf(out_file
, field
, indent
+ 2);
452 fprintf(out_file
, "\n%*s]", indent
, "");
454 if (vmsd
->subsections
!= NULL
) {
455 const VMStateDescription
**subsection
= vmsd
->subsections
;
458 fprintf(out_file
, ",\n%*s\"Subsections\": [\n", indent
, "");
460 while (*subsection
!= NULL
) {
462 fprintf(out_file
, ",\n");
464 dump_vmstate_vmss(out_file
, subsection
, indent
+ 2);
468 fprintf(out_file
, "\n%*s]", indent
, "");
470 fprintf(out_file
, "\n%*s}", indent
- 2, "");
473 static void dump_machine_type(FILE *out_file
)
477 mc
= MACHINE_GET_CLASS(current_machine
);
479 fprintf(out_file
, " \"vmschkmachine\": {\n");
480 fprintf(out_file
, " \"Name\": \"%s\"\n", mc
->name
);
481 fprintf(out_file
, " },\n");
484 void dump_vmstate_json_to_file(FILE *out_file
)
489 fprintf(out_file
, "{\n");
490 dump_machine_type(out_file
);
493 list
= object_class_get_list(TYPE_DEVICE
, true);
494 for (elt
= list
; elt
; elt
= elt
->next
) {
495 DeviceClass
*dc
= OBJECT_CLASS_CHECK(DeviceClass
, elt
->data
,
505 fprintf(out_file
, ",\n");
507 name
= object_class_get_name(OBJECT_CLASS(dc
));
508 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", name
);
510 fprintf(out_file
, "%*s\"Name\": \"%s\",\n", indent
, "", name
);
511 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
512 dc
->vmsd
->version_id
);
513 fprintf(out_file
, "%*s\"minimum_version_id\": %d,\n", indent
, "",
514 dc
->vmsd
->minimum_version_id
);
516 dump_vmstate_vmsd(out_file
, dc
->vmsd
, indent
, false);
518 fprintf(out_file
, "\n%*s}", indent
- 2, "");
521 fprintf(out_file
, "\n}\n");
525 static int calculate_new_instance_id(const char *idstr
)
530 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
531 if (strcmp(idstr
, se
->idstr
) == 0
532 && instance_id
<= se
->instance_id
) {
533 instance_id
= se
->instance_id
+ 1;
539 static int calculate_compat_instance_id(const char *idstr
)
544 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
549 if (strcmp(idstr
, se
->compat
->idstr
) == 0
550 && instance_id
<= se
->compat
->instance_id
) {
551 instance_id
= se
->compat
->instance_id
+ 1;
557 static inline MigrationPriority
save_state_priority(SaveStateEntry
*se
)
560 return se
->vmsd
->priority
;
562 return MIG_PRI_DEFAULT
;
565 static void savevm_state_handler_insert(SaveStateEntry
*nse
)
567 MigrationPriority priority
= save_state_priority(nse
);
570 assert(priority
<= MIG_PRI_MAX
);
572 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
573 if (save_state_priority(se
) < priority
) {
579 QTAILQ_INSERT_BEFORE(se
, nse
, entry
);
581 QTAILQ_INSERT_TAIL(&savevm_state
.handlers
, nse
, entry
);
585 /* TODO: Individual devices generally have very little idea about the rest
586 of the system, so instance_id should be removed/replaced.
587 Meanwhile pass -1 as instance_id if you do not already have a clearly
588 distinguishing id for all instances of your device class. */
589 int register_savevm_live(DeviceState
*dev
,
598 se
= g_new0(SaveStateEntry
, 1);
599 se
->version_id
= version_id
;
600 se
->section_id
= savevm_state
.global_section_id
++;
604 /* if this is a live_savem then set is_ram */
605 if (ops
->save_live_setup
!= NULL
) {
610 char *id
= qdev_get_dev_path(dev
);
612 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
614 error_report("Path too long for VMState (%s)", id
);
622 se
->compat
= g_new0(CompatEntry
, 1);
623 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), idstr
);
624 se
->compat
->instance_id
= instance_id
== -1 ?
625 calculate_compat_instance_id(idstr
) : instance_id
;
629 pstrcat(se
->idstr
, sizeof(se
->idstr
), idstr
);
631 if (instance_id
== -1) {
632 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
634 se
->instance_id
= instance_id
;
636 assert(!se
->compat
|| se
->instance_id
== 0);
637 savevm_state_handler_insert(se
);
641 int register_savevm(DeviceState
*dev
,
645 SaveStateHandler
*save_state
,
646 LoadStateHandler
*load_state
,
649 SaveVMHandlers
*ops
= g_new0(SaveVMHandlers
, 1);
650 ops
->save_state
= save_state
;
651 ops
->load_state
= load_state
;
652 return register_savevm_live(dev
, idstr
, instance_id
, version_id
,
656 void unregister_savevm(DeviceState
*dev
, const char *idstr
, void *opaque
)
658 SaveStateEntry
*se
, *new_se
;
662 char *path
= qdev_get_dev_path(dev
);
664 pstrcpy(id
, sizeof(id
), path
);
665 pstrcat(id
, sizeof(id
), "/");
669 pstrcat(id
, sizeof(id
), idstr
);
671 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
672 if (strcmp(se
->idstr
, id
) == 0 && se
->opaque
== opaque
) {
673 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
681 int vmstate_register_with_alias_id(DeviceState
*dev
, int instance_id
,
682 const VMStateDescription
*vmsd
,
683 void *opaque
, int alias_id
,
684 int required_for_version
,
689 /* If this triggers, alias support can be dropped for the vmsd. */
690 assert(alias_id
== -1 || required_for_version
>= vmsd
->minimum_version_id
);
692 se
= g_new0(SaveStateEntry
, 1);
693 se
->version_id
= vmsd
->version_id
;
694 se
->section_id
= savevm_state
.global_section_id
++;
697 se
->alias_id
= alias_id
;
700 char *id
= qdev_get_dev_path(dev
);
702 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
704 error_setg(errp
, "Path too long for VMState (%s)", id
);
712 se
->compat
= g_new0(CompatEntry
, 1);
713 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), vmsd
->name
);
714 se
->compat
->instance_id
= instance_id
== -1 ?
715 calculate_compat_instance_id(vmsd
->name
) : instance_id
;
719 pstrcat(se
->idstr
, sizeof(se
->idstr
), vmsd
->name
);
721 if (instance_id
== -1) {
722 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
724 se
->instance_id
= instance_id
;
726 assert(!se
->compat
|| se
->instance_id
== 0);
727 savevm_state_handler_insert(se
);
731 void vmstate_unregister(DeviceState
*dev
, const VMStateDescription
*vmsd
,
734 SaveStateEntry
*se
, *new_se
;
736 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
737 if (se
->vmsd
== vmsd
&& se
->opaque
== opaque
) {
738 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
745 static int vmstate_load(QEMUFile
*f
, SaveStateEntry
*se
, int version_id
)
747 trace_vmstate_load(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
748 if (!se
->vmsd
) { /* Old style */
749 return se
->ops
->load_state(f
, se
->opaque
, version_id
);
751 return vmstate_load_state(f
, se
->vmsd
, se
->opaque
, version_id
);
754 static void vmstate_save_old_style(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
756 int64_t old_offset
, size
;
758 old_offset
= qemu_ftell_fast(f
);
759 se
->ops
->save_state(f
, se
->opaque
);
760 size
= qemu_ftell_fast(f
) - old_offset
;
763 json_prop_int(vmdesc
, "size", size
);
764 json_start_array(vmdesc
, "fields");
765 json_start_object(vmdesc
, NULL
);
766 json_prop_str(vmdesc
, "name", "data");
767 json_prop_int(vmdesc
, "size", size
);
768 json_prop_str(vmdesc
, "type", "buffer");
769 json_end_object(vmdesc
);
770 json_end_array(vmdesc
);
774 static void vmstate_save(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
776 trace_vmstate_save(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
778 vmstate_save_old_style(f
, se
, vmdesc
);
781 vmstate_save_state(f
, se
->vmsd
, se
->opaque
, vmdesc
);
784 void savevm_skip_section_footers(void)
786 skip_section_footers
= true;
790 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
792 static void save_section_header(QEMUFile
*f
, SaveStateEntry
*se
,
793 uint8_t section_type
)
795 qemu_put_byte(f
, section_type
);
796 qemu_put_be32(f
, se
->section_id
);
798 if (section_type
== QEMU_VM_SECTION_FULL
||
799 section_type
== QEMU_VM_SECTION_START
) {
801 size_t len
= strlen(se
->idstr
);
802 qemu_put_byte(f
, len
);
803 qemu_put_buffer(f
, (uint8_t *)se
->idstr
, len
);
805 qemu_put_be32(f
, se
->instance_id
);
806 qemu_put_be32(f
, se
->version_id
);
811 * Write a footer onto device sections that catches cases misformatted device
814 static void save_section_footer(QEMUFile
*f
, SaveStateEntry
*se
)
816 if (!skip_section_footers
) {
817 qemu_put_byte(f
, QEMU_VM_SECTION_FOOTER
);
818 qemu_put_be32(f
, se
->section_id
);
823 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
824 * command and associated data.
826 * @f: File to send command on
827 * @command: Command type to send
828 * @len: Length of associated data
829 * @data: Data associated with command.
831 static void qemu_savevm_command_send(QEMUFile
*f
,
832 enum qemu_vm_cmd command
,
836 trace_savevm_command_send(command
, len
);
837 qemu_put_byte(f
, QEMU_VM_COMMAND
);
838 qemu_put_be16(f
, (uint16_t)command
);
839 qemu_put_be16(f
, len
);
840 qemu_put_buffer(f
, data
, len
);
844 void qemu_savevm_send_ping(QEMUFile
*f
, uint32_t value
)
848 trace_savevm_send_ping(value
);
849 buf
= cpu_to_be32(value
);
850 qemu_savevm_command_send(f
, MIG_CMD_PING
, sizeof(value
), (uint8_t *)&buf
);
853 void qemu_savevm_send_open_return_path(QEMUFile
*f
)
855 trace_savevm_send_open_return_path();
856 qemu_savevm_command_send(f
, MIG_CMD_OPEN_RETURN_PATH
, 0, NULL
);
859 /* We have a buffer of data to send; we don't want that all to be loaded
860 * by the command itself, so the command contains just the length of the
861 * extra buffer that we then send straight after it.
862 * TODO: Must be a better way to organise that
868 int qemu_savevm_send_packaged(QEMUFile
*f
, const uint8_t *buf
, size_t len
)
872 if (len
> MAX_VM_CMD_PACKAGED_SIZE
) {
873 error_report("%s: Unreasonably large packaged state: %zu",
878 tmp
= cpu_to_be32(len
);
880 trace_qemu_savevm_send_packaged();
881 qemu_savevm_command_send(f
, MIG_CMD_PACKAGED
, 4, (uint8_t *)&tmp
);
883 qemu_put_buffer(f
, buf
, len
);
888 /* Send prior to any postcopy transfer */
889 void qemu_savevm_send_postcopy_advise(QEMUFile
*f
)
892 tmp
[0] = cpu_to_be64(ram_pagesize_summary());
893 tmp
[1] = cpu_to_be64(qemu_target_page_size());
895 trace_qemu_savevm_send_postcopy_advise();
896 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_ADVISE
, 16, (uint8_t *)tmp
);
899 /* Sent prior to starting the destination running in postcopy, discard pages
900 * that have already been sent but redirtied on the source.
901 * CMD_POSTCOPY_RAM_DISCARD consist of:
903 * byte Length of name field (not including 0)
904 * n x byte RAM block name
905 * byte 0 terminator (just for safety)
906 * n x Byte ranges within the named RAMBlock
907 * be64 Start of the range
910 * name: RAMBlock name that these entries are part of
911 * len: Number of page entries
912 * start_list: 'len' addresses
913 * length_list: 'len' addresses
916 void qemu_savevm_send_postcopy_ram_discard(QEMUFile
*f
, const char *name
,
918 uint64_t *start_list
,
919 uint64_t *length_list
)
924 size_t name_len
= strlen(name
);
926 trace_qemu_savevm_send_postcopy_ram_discard(name
, len
);
927 assert(name_len
< 256);
928 buf
= g_malloc0(1 + 1 + name_len
+ 1 + (8 + 8) * len
);
929 buf
[0] = postcopy_ram_discard_version
;
931 memcpy(buf
+ 2, name
, name_len
);
932 tmplen
= 2 + name_len
;
933 buf
[tmplen
++] = '\0';
935 for (t
= 0; t
< len
; t
++) {
936 stq_be_p(buf
+ tmplen
, start_list
[t
]);
938 stq_be_p(buf
+ tmplen
, length_list
[t
]);
941 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RAM_DISCARD
, tmplen
, buf
);
945 /* Get the destination into a state where it can receive postcopy data. */
946 void qemu_savevm_send_postcopy_listen(QEMUFile
*f
)
948 trace_savevm_send_postcopy_listen();
949 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_LISTEN
, 0, NULL
);
952 /* Kick the destination into running */
953 void qemu_savevm_send_postcopy_run(QEMUFile
*f
)
955 trace_savevm_send_postcopy_run();
956 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RUN
, 0, NULL
);
959 bool qemu_savevm_state_blocked(Error
**errp
)
963 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
964 if (se
->vmsd
&& se
->vmsd
->unmigratable
) {
965 error_setg(errp
, "State blocked by non-migratable device '%s'",
973 static bool enforce_config_section(void)
975 MachineState
*machine
= MACHINE(qdev_get_machine());
976 return machine
->enforce_config_section
;
979 void qemu_savevm_state_header(QEMUFile
*f
)
981 trace_savevm_state_header();
982 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
983 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
985 if (!savevm_state
.skip_configuration
|| enforce_config_section()) {
986 qemu_put_byte(f
, QEMU_VM_CONFIGURATION
);
987 vmstate_save_state(f
, &vmstate_configuration
, &savevm_state
, 0);
992 void qemu_savevm_state_begin(QEMUFile
*f
)
997 trace_savevm_state_begin();
998 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
999 if (!se
->ops
|| !se
->ops
->save_live_setup
) {
1002 if (se
->ops
&& se
->ops
->is_active
) {
1003 if (!se
->ops
->is_active(se
->opaque
)) {
1007 save_section_header(f
, se
, QEMU_VM_SECTION_START
);
1009 ret
= se
->ops
->save_live_setup(f
, se
->opaque
);
1010 save_section_footer(f
, se
);
1012 qemu_file_set_error(f
, ret
);
1019 * this function has three return values:
1020 * negative: there was one error, and we have -errno.
1021 * 0 : We haven't finished, caller have to go again
1022 * 1 : We have finished, we can go to complete phase
1024 int qemu_savevm_state_iterate(QEMUFile
*f
, bool postcopy
)
1029 trace_savevm_state_iterate();
1030 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1031 if (!se
->ops
|| !se
->ops
->save_live_iterate
) {
1034 if (se
->ops
&& se
->ops
->is_active
) {
1035 if (!se
->ops
->is_active(se
->opaque
)) {
1040 * In the postcopy phase, any device that doesn't know how to
1041 * do postcopy should have saved it's state in the _complete
1042 * call that's already run, it might get confused if we call
1043 * iterate afterwards.
1045 if (postcopy
&& !se
->ops
->save_live_complete_postcopy
) {
1048 if (qemu_file_rate_limit(f
)) {
1051 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1053 save_section_header(f
, se
, QEMU_VM_SECTION_PART
);
1055 ret
= se
->ops
->save_live_iterate(f
, se
->opaque
);
1056 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1057 save_section_footer(f
, se
);
1060 qemu_file_set_error(f
, ret
);
1063 /* Do not proceed to the next vmstate before this one reported
1064 completion of the current stage. This serializes the migration
1065 and reduces the probability that a faster changing state is
1066 synchronized over and over again. */
1073 static bool should_send_vmdesc(void)
1075 MachineState
*machine
= MACHINE(qdev_get_machine());
1076 bool in_postcopy
= migration_in_postcopy();
1077 return !machine
->suppress_vmdesc
&& !in_postcopy
;
1081 * Calls the save_live_complete_postcopy methods
1082 * causing the last few pages to be sent immediately and doing any associated
1084 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
1085 * all the other devices, but that happens at the point we switch to postcopy.
1087 void qemu_savevm_state_complete_postcopy(QEMUFile
*f
)
1092 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1093 if (!se
->ops
|| !se
->ops
->save_live_complete_postcopy
) {
1096 if (se
->ops
&& se
->ops
->is_active
) {
1097 if (!se
->ops
->is_active(se
->opaque
)) {
1101 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1103 qemu_put_byte(f
, QEMU_VM_SECTION_END
);
1104 qemu_put_be32(f
, se
->section_id
);
1106 ret
= se
->ops
->save_live_complete_postcopy(f
, se
->opaque
);
1107 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1108 save_section_footer(f
, se
);
1110 qemu_file_set_error(f
, ret
);
1115 qemu_put_byte(f
, QEMU_VM_EOF
);
1119 void qemu_savevm_state_complete_precopy(QEMUFile
*f
, bool iterable_only
)
1125 bool in_postcopy
= migration_in_postcopy();
1127 trace_savevm_state_complete_precopy();
1129 cpu_synchronize_all_states();
1131 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1133 (in_postcopy
&& se
->ops
->save_live_complete_postcopy
) ||
1134 (in_postcopy
&& !iterable_only
) ||
1135 !se
->ops
->save_live_complete_precopy
) {
1139 if (se
->ops
&& se
->ops
->is_active
) {
1140 if (!se
->ops
->is_active(se
->opaque
)) {
1144 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1146 save_section_header(f
, se
, QEMU_VM_SECTION_END
);
1148 ret
= se
->ops
->save_live_complete_precopy(f
, se
->opaque
);
1149 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1150 save_section_footer(f
, se
);
1152 qemu_file_set_error(f
, ret
);
1157 if (iterable_only
) {
1161 vmdesc
= qjson_new();
1162 json_prop_int(vmdesc
, "page_size", qemu_target_page_size());
1163 json_start_array(vmdesc
, "devices");
1164 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1166 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1169 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1170 trace_savevm_section_skip(se
->idstr
, se
->section_id
);
1174 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1176 json_start_object(vmdesc
, NULL
);
1177 json_prop_str(vmdesc
, "name", se
->idstr
);
1178 json_prop_int(vmdesc
, "instance_id", se
->instance_id
);
1180 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1181 vmstate_save(f
, se
, vmdesc
);
1182 trace_savevm_section_end(se
->idstr
, se
->section_id
, 0);
1183 save_section_footer(f
, se
);
1185 json_end_object(vmdesc
);
1189 /* Postcopy stream will still be going */
1190 qemu_put_byte(f
, QEMU_VM_EOF
);
1193 json_end_array(vmdesc
);
1194 qjson_finish(vmdesc
);
1195 vmdesc_len
= strlen(qjson_get_str(vmdesc
));
1197 if (should_send_vmdesc()) {
1198 qemu_put_byte(f
, QEMU_VM_VMDESCRIPTION
);
1199 qemu_put_be32(f
, vmdesc_len
);
1200 qemu_put_buffer(f
, (uint8_t *)qjson_get_str(vmdesc
), vmdesc_len
);
1202 qjson_destroy(vmdesc
);
1207 /* Give an estimate of the amount left to be transferred,
1208 * the result is split into the amount for units that can and
1209 * for units that can't do postcopy.
1211 void qemu_savevm_state_pending(QEMUFile
*f
, uint64_t threshold_size
,
1212 uint64_t *res_non_postcopiable
,
1213 uint64_t *res_postcopiable
)
1217 *res_non_postcopiable
= 0;
1218 *res_postcopiable
= 0;
1221 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1222 if (!se
->ops
|| !se
->ops
->save_live_pending
) {
1225 if (se
->ops
&& se
->ops
->is_active
) {
1226 if (!se
->ops
->is_active(se
->opaque
)) {
1230 se
->ops
->save_live_pending(f
, se
->opaque
, threshold_size
,
1231 res_non_postcopiable
, res_postcopiable
);
1235 void qemu_savevm_state_cleanup(void)
1239 trace_savevm_state_cleanup();
1240 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1241 if (se
->ops
&& se
->ops
->cleanup
) {
1242 se
->ops
->cleanup(se
->opaque
);
1247 static int qemu_savevm_state(QEMUFile
*f
, Error
**errp
)
1250 MigrationState
*ms
= migrate_init();
1251 MigrationStatus status
;
1252 ms
->to_dst_file
= f
;
1254 if (migration_is_blocked(errp
)) {
1259 if (migrate_use_block()) {
1260 error_setg(errp
, "Block migration and snapshots are incompatible");
1265 qemu_mutex_unlock_iothread();
1266 qemu_savevm_state_header(f
);
1267 qemu_savevm_state_begin(f
);
1268 qemu_mutex_lock_iothread();
1270 while (qemu_file_get_error(f
) == 0) {
1271 if (qemu_savevm_state_iterate(f
, false) > 0) {
1276 ret
= qemu_file_get_error(f
);
1278 qemu_savevm_state_complete_precopy(f
, false);
1279 ret
= qemu_file_get_error(f
);
1281 qemu_savevm_state_cleanup();
1283 error_setg_errno(errp
, -ret
, "Error while writing VM state");
1288 status
= MIGRATION_STATUS_FAILED
;
1290 status
= MIGRATION_STATUS_COMPLETED
;
1292 migrate_set_state(&ms
->state
, MIGRATION_STATUS_SETUP
, status
);
1294 /* f is outer parameter, it should not stay in global migration state after
1295 * this function finished */
1296 ms
->to_dst_file
= NULL
;
1301 static int qemu_save_device_state(QEMUFile
*f
)
1305 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
1306 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
1308 cpu_synchronize_all_states();
1310 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1314 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1317 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1321 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1323 vmstate_save(f
, se
, NULL
);
1325 save_section_footer(f
, se
);
1328 qemu_put_byte(f
, QEMU_VM_EOF
);
1330 return qemu_file_get_error(f
);
1333 static SaveStateEntry
*find_se(const char *idstr
, int instance_id
)
1337 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1338 if (!strcmp(se
->idstr
, idstr
) &&
1339 (instance_id
== se
->instance_id
||
1340 instance_id
== se
->alias_id
))
1342 /* Migrating from an older version? */
1343 if (strstr(se
->idstr
, idstr
) && se
->compat
) {
1344 if (!strcmp(se
->compat
->idstr
, idstr
) &&
1345 (instance_id
== se
->compat
->instance_id
||
1346 instance_id
== se
->alias_id
))
1353 enum LoadVMExitCodes
{
1354 /* Allow a command to quit all layers of nested loadvm loops */
1358 static int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
);
1360 /* ------ incoming postcopy messages ------ */
1361 /* 'advise' arrives before any transfers just to tell us that a postcopy
1362 * *might* happen - it might be skipped if precopy transferred everything
1365 static int loadvm_postcopy_handle_advise(MigrationIncomingState
*mis
)
1367 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1368 uint64_t remote_pagesize_summary
, local_pagesize_summary
, remote_tps
;
1370 trace_loadvm_postcopy_handle_advise();
1371 if (ps
!= POSTCOPY_INCOMING_NONE
) {
1372 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps
);
1376 if (!postcopy_ram_supported_by_host()) {
1377 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
1381 remote_pagesize_summary
= qemu_get_be64(mis
->from_src_file
);
1382 local_pagesize_summary
= ram_pagesize_summary();
1384 if (remote_pagesize_summary
!= local_pagesize_summary
) {
1386 * This detects two potential causes of mismatch:
1387 * a) A mismatch in host page sizes
1388 * Some combinations of mismatch are probably possible but it gets
1389 * a bit more complicated. In particular we need to place whole
1390 * host pages on the dest at once, and we need to ensure that we
1391 * handle dirtying to make sure we never end up sending part of
1392 * a hostpage on it's own.
1393 * b) The use of different huge page sizes on source/destination
1394 * a more fine grain test is performed during RAM block migration
1395 * but this test here causes a nice early clear failure, and
1396 * also fails when passed to an older qemu that doesn't
1399 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
1401 remote_pagesize_summary
, local_pagesize_summary
);
1405 remote_tps
= qemu_get_be64(mis
->from_src_file
);
1406 if (remote_tps
!= qemu_target_page_size()) {
1408 * Again, some differences could be dealt with, but for now keep it
1411 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
1412 (int)remote_tps
, qemu_target_page_size());
1416 if (ram_postcopy_incoming_init(mis
)) {
1420 postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1425 /* After postcopy we will be told to throw some pages away since they're
1426 * dirty and will have to be demand fetched. Must happen before CPU is
1428 * There can be 0..many of these messages, each encoding multiple pages.
1430 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState
*mis
,
1435 PostcopyState ps
= postcopy_state_get();
1437 trace_loadvm_postcopy_ram_handle_discard();
1440 case POSTCOPY_INCOMING_ADVISE
:
1442 tmp
= postcopy_ram_prepare_discard(mis
);
1448 case POSTCOPY_INCOMING_DISCARD
:
1449 /* Expected state */
1453 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
1457 /* We're expecting a
1459 * a RAM ID string (length byte, name, 0 term)
1460 * then at least 1 16 byte chunk
1462 if (len
< (1 + 1 + 1 + 1 + 2 * 8)) {
1463 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1467 tmp
= qemu_get_byte(mis
->from_src_file
);
1468 if (tmp
!= postcopy_ram_discard_version
) {
1469 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp
);
1473 if (!qemu_get_counted_string(mis
->from_src_file
, ramid
)) {
1474 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
1477 tmp
= qemu_get_byte(mis
->from_src_file
);
1479 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp
);
1483 len
-= 3 + strlen(ramid
);
1485 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1488 trace_loadvm_postcopy_ram_handle_discard_header(ramid
, len
);
1490 uint64_t start_addr
, block_length
;
1491 start_addr
= qemu_get_be64(mis
->from_src_file
);
1492 block_length
= qemu_get_be64(mis
->from_src_file
);
1495 int ret
= ram_discard_range(ramid
, start_addr
, block_length
);
1500 trace_loadvm_postcopy_ram_handle_discard_end();
1506 * Triggered by a postcopy_listen command; this thread takes over reading
1507 * the input stream, leaving the main thread free to carry on loading the rest
1508 * of the device state (from RAM).
1509 * (TODO:This could do with being in a postcopy file - but there again it's
1510 * just another input loop, not that postcopy specific)
1512 static void *postcopy_ram_listen_thread(void *opaque
)
1514 QEMUFile
*f
= opaque
;
1515 MigrationIncomingState
*mis
= migration_incoming_get_current();
1518 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
1519 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1520 qemu_sem_post(&mis
->listen_thread_sem
);
1521 trace_postcopy_ram_listen_thread_start();
1524 * Because we're a thread and not a coroutine we can't yield
1525 * in qemu_file, and thus we must be blocking now.
1527 qemu_file_set_blocking(f
, true);
1528 load_res
= qemu_loadvm_state_main(f
, mis
);
1529 /* And non-blocking again so we don't block in any cleanup */
1530 qemu_file_set_blocking(f
, false);
1532 trace_postcopy_ram_listen_thread_exit();
1534 error_report("%s: loadvm failed: %d", __func__
, load_res
);
1535 qemu_file_set_error(f
, load_res
);
1536 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1537 MIGRATION_STATUS_FAILED
);
1540 * This looks good, but it's possible that the device loading in the
1541 * main thread hasn't finished yet, and so we might not be in 'RUN'
1542 * state yet; wait for the end of the main thread.
1544 qemu_event_wait(&mis
->main_thread_load_event
);
1546 postcopy_ram_incoming_cleanup(mis
);
1550 * If something went wrong then we have a bad state so exit;
1551 * depending how far we got it might be possible at this point
1552 * to leave the guest running and fire MCEs for pages that never
1553 * arrived as a desperate recovery step.
1558 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1559 MIGRATION_STATUS_COMPLETED
);
1561 * If everything has worked fine, then the main thread has waited
1562 * for us to start, and we're the last use of the mis.
1563 * (If something broke then qemu will have to exit anyway since it's
1564 * got a bad migration state).
1566 migration_incoming_state_destroy();
1572 /* After this message we must be able to immediately receive postcopy data */
1573 static int loadvm_postcopy_handle_listen(MigrationIncomingState
*mis
)
1575 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_LISTENING
);
1576 trace_loadvm_postcopy_handle_listen();
1577 if (ps
!= POSTCOPY_INCOMING_ADVISE
&& ps
!= POSTCOPY_INCOMING_DISCARD
) {
1578 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps
);
1581 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
1583 * A rare case, we entered listen without having to do any discards,
1584 * so do the setup that's normally done at the time of the 1st discard.
1586 postcopy_ram_prepare_discard(mis
);
1590 * Sensitise RAM - can now generate requests for blocks that don't exist
1591 * However, at this point the CPU shouldn't be running, and the IO
1592 * shouldn't be doing anything yet so don't actually expect requests
1594 if (postcopy_ram_enable_notify(mis
)) {
1598 if (mis
->have_listen_thread
) {
1599 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
1603 mis
->have_listen_thread
= true;
1604 /* Start up the listening thread and wait for it to signal ready */
1605 qemu_sem_init(&mis
->listen_thread_sem
, 0);
1606 qemu_thread_create(&mis
->listen_thread
, "postcopy/listen",
1607 postcopy_ram_listen_thread
, mis
->from_src_file
,
1608 QEMU_THREAD_DETACHED
);
1609 qemu_sem_wait(&mis
->listen_thread_sem
);
1610 qemu_sem_destroy(&mis
->listen_thread_sem
);
1620 static void loadvm_postcopy_handle_run_bh(void *opaque
)
1622 Error
*local_err
= NULL
;
1623 HandleRunBhData
*data
= opaque
;
1625 /* TODO we should move all of this lot into postcopy_ram.c or a shared code
1628 cpu_synchronize_all_post_init();
1630 qemu_announce_self();
1632 /* Make sure all file formats flush their mutable metadata.
1633 * If we get an error here, just don't restart the VM yet. */
1634 bdrv_invalidate_cache_all(&local_err
);
1636 error_report_err(local_err
);
1641 trace_loadvm_postcopy_handle_run_cpu_sync();
1642 cpu_synchronize_all_post_init();
1644 trace_loadvm_postcopy_handle_run_vmstart();
1647 /* Hold onto your hats, starting the CPU */
1650 /* leave it paused and let management decide when to start the CPU */
1651 runstate_set(RUN_STATE_PAUSED
);
1654 qemu_bh_delete(data
->bh
);
1658 /* After all discards we can start running and asking for pages */
1659 static int loadvm_postcopy_handle_run(MigrationIncomingState
*mis
)
1661 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_RUNNING
);
1662 HandleRunBhData
*data
;
1664 trace_loadvm_postcopy_handle_run();
1665 if (ps
!= POSTCOPY_INCOMING_LISTENING
) {
1666 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps
);
1670 data
= g_new(HandleRunBhData
, 1);
1671 data
->bh
= qemu_bh_new(loadvm_postcopy_handle_run_bh
, data
);
1672 qemu_bh_schedule(data
->bh
);
1674 /* We need to finish reading the stream from the package
1675 * and also stop reading anything more from the stream that loaded the
1676 * package (since it's now being read by the listener thread).
1677 * LOADVM_QUIT will quit all the layers of nested loadvm loops.
1683 * Immediately following this command is a blob of data containing an embedded
1684 * chunk of migration stream; read it and load it.
1686 * @mis: Incoming state
1687 * @length: Length of packaged data to read
1689 * Returns: Negative values on error
1692 static int loadvm_handle_cmd_packaged(MigrationIncomingState
*mis
)
1696 QIOChannelBuffer
*bioc
;
1698 length
= qemu_get_be32(mis
->from_src_file
);
1699 trace_loadvm_handle_cmd_packaged(length
);
1701 if (length
> MAX_VM_CMD_PACKAGED_SIZE
) {
1702 error_report("Unreasonably large packaged state: %zu", length
);
1706 bioc
= qio_channel_buffer_new(length
);
1707 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-loadvm-buffer");
1708 ret
= qemu_get_buffer(mis
->from_src_file
,
1711 if (ret
!= length
) {
1712 object_unref(OBJECT(bioc
));
1713 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
1715 return (ret
< 0) ? ret
: -EAGAIN
;
1717 bioc
->usage
+= length
;
1718 trace_loadvm_handle_cmd_packaged_received(ret
);
1720 QEMUFile
*packf
= qemu_fopen_channel_input(QIO_CHANNEL(bioc
));
1722 ret
= qemu_loadvm_state_main(packf
, mis
);
1723 trace_loadvm_handle_cmd_packaged_main(ret
);
1725 object_unref(OBJECT(bioc
));
1731 * Process an incoming 'QEMU_VM_COMMAND'
1732 * 0 just a normal return
1733 * LOADVM_QUIT All good, but exit the loop
1736 static int loadvm_process_command(QEMUFile
*f
)
1738 MigrationIncomingState
*mis
= migration_incoming_get_current();
1743 cmd
= qemu_get_be16(f
);
1744 len
= qemu_get_be16(f
);
1746 trace_loadvm_process_command(cmd
, len
);
1747 if (cmd
>= MIG_CMD_MAX
|| cmd
== MIG_CMD_INVALID
) {
1748 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd
, len
);
1752 if (mig_cmd_args
[cmd
].len
!= -1 && mig_cmd_args
[cmd
].len
!= len
) {
1753 error_report("%s received with bad length - expecting %zu, got %d",
1754 mig_cmd_args
[cmd
].name
,
1755 (size_t)mig_cmd_args
[cmd
].len
, len
);
1760 case MIG_CMD_OPEN_RETURN_PATH
:
1761 if (mis
->to_src_file
) {
1762 error_report("CMD_OPEN_RETURN_PATH called when RP already open");
1763 /* Not really a problem, so don't give up */
1766 mis
->to_src_file
= qemu_file_get_return_path(f
);
1767 if (!mis
->to_src_file
) {
1768 error_report("CMD_OPEN_RETURN_PATH failed");
1774 tmp32
= qemu_get_be32(f
);
1775 trace_loadvm_process_command_ping(tmp32
);
1776 if (!mis
->to_src_file
) {
1777 error_report("CMD_PING (0x%x) received with no return path",
1781 migrate_send_rp_pong(mis
, tmp32
);
1784 case MIG_CMD_PACKAGED
:
1785 return loadvm_handle_cmd_packaged(mis
);
1787 case MIG_CMD_POSTCOPY_ADVISE
:
1788 return loadvm_postcopy_handle_advise(mis
);
1790 case MIG_CMD_POSTCOPY_LISTEN
:
1791 return loadvm_postcopy_handle_listen(mis
);
1793 case MIG_CMD_POSTCOPY_RUN
:
1794 return loadvm_postcopy_handle_run(mis
);
1796 case MIG_CMD_POSTCOPY_RAM_DISCARD
:
1797 return loadvm_postcopy_ram_handle_discard(mis
, len
);
1803 struct LoadStateEntry
{
1804 QLIST_ENTRY(LoadStateEntry
) entry
;
1811 * Read a footer off the wire and check that it matches the expected section
1813 * Returns: true if the footer was good
1814 * false if there is a problem (and calls error_report to say why)
1816 static bool check_section_footer(QEMUFile
*f
, LoadStateEntry
*le
)
1819 uint32_t read_section_id
;
1821 if (skip_section_footers
) {
1822 /* No footer to check */
1826 read_mark
= qemu_get_byte(f
);
1828 if (read_mark
!= QEMU_VM_SECTION_FOOTER
) {
1829 error_report("Missing section footer for %s", le
->se
->idstr
);
1833 read_section_id
= qemu_get_be32(f
);
1834 if (read_section_id
!= le
->section_id
) {
1835 error_report("Mismatched section id in footer for %s -"
1836 " read 0x%x expected 0x%x",
1837 le
->se
->idstr
, read_section_id
, le
->section_id
);
1845 void loadvm_free_handlers(MigrationIncomingState
*mis
)
1847 LoadStateEntry
*le
, *new_le
;
1849 QLIST_FOREACH_SAFE(le
, &mis
->loadvm_handlers
, entry
, new_le
) {
1850 QLIST_REMOVE(le
, entry
);
1856 qemu_loadvm_section_start_full(QEMUFile
*f
, MigrationIncomingState
*mis
)
1858 uint32_t instance_id
, version_id
, section_id
;
1864 /* Read section start */
1865 section_id
= qemu_get_be32(f
);
1866 if (!qemu_get_counted_string(f
, idstr
)) {
1867 error_report("Unable to read ID string for section %u",
1871 instance_id
= qemu_get_be32(f
);
1872 version_id
= qemu_get_be32(f
);
1874 trace_qemu_loadvm_state_section_startfull(section_id
, idstr
,
1875 instance_id
, version_id
);
1876 /* Find savevm section */
1877 se
= find_se(idstr
, instance_id
);
1879 error_report("Unknown savevm section or instance '%s' %d",
1880 idstr
, instance_id
);
1884 /* Validate version */
1885 if (version_id
> se
->version_id
) {
1886 error_report("savevm: unsupported version %d for '%s' v%d",
1887 version_id
, idstr
, se
->version_id
);
1891 /* Validate if it is a device's state */
1892 if (xen_enabled() && se
->is_ram
) {
1893 error_report("loadvm: %s RAM loading not allowed on Xen", idstr
);
1898 le
= g_malloc0(sizeof(*le
));
1901 le
->section_id
= section_id
;
1902 le
->version_id
= version_id
;
1903 QLIST_INSERT_HEAD(&mis
->loadvm_handlers
, le
, entry
);
1905 ret
= vmstate_load(f
, le
->se
, le
->version_id
);
1907 error_report("error while loading state for instance 0x%x of"
1908 " device '%s'", instance_id
, idstr
);
1911 if (!check_section_footer(f
, le
)) {
1919 qemu_loadvm_section_part_end(QEMUFile
*f
, MigrationIncomingState
*mis
)
1921 uint32_t section_id
;
1925 section_id
= qemu_get_be32(f
);
1927 trace_qemu_loadvm_state_section_partend(section_id
);
1928 QLIST_FOREACH(le
, &mis
->loadvm_handlers
, entry
) {
1929 if (le
->section_id
== section_id
) {
1934 error_report("Unknown savevm section %d", section_id
);
1938 ret
= vmstate_load(f
, le
->se
, le
->version_id
);
1940 error_report("error while loading state section id %d(%s)",
1941 section_id
, le
->se
->idstr
);
1944 if (!check_section_footer(f
, le
)) {
1951 static int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
)
1953 uint8_t section_type
;
1956 while ((section_type
= qemu_get_byte(f
)) != QEMU_VM_EOF
) {
1958 trace_qemu_loadvm_state_section(section_type
);
1959 switch (section_type
) {
1960 case QEMU_VM_SECTION_START
:
1961 case QEMU_VM_SECTION_FULL
:
1962 ret
= qemu_loadvm_section_start_full(f
, mis
);
1967 case QEMU_VM_SECTION_PART
:
1968 case QEMU_VM_SECTION_END
:
1969 ret
= qemu_loadvm_section_part_end(f
, mis
);
1974 case QEMU_VM_COMMAND
:
1975 ret
= loadvm_process_command(f
);
1976 trace_qemu_loadvm_state_section_command(ret
);
1977 if ((ret
< 0) || (ret
& LOADVM_QUIT
)) {
1982 error_report("Unknown savevm section type %d", section_type
);
1990 qemu_file_set_error(f
, ret
);
1995 int qemu_loadvm_state(QEMUFile
*f
)
1997 MigrationIncomingState
*mis
= migration_incoming_get_current();
1998 Error
*local_err
= NULL
;
2002 if (qemu_savevm_state_blocked(&local_err
)) {
2003 error_report_err(local_err
);
2007 v
= qemu_get_be32(f
);
2008 if (v
!= QEMU_VM_FILE_MAGIC
) {
2009 error_report("Not a migration stream");
2013 v
= qemu_get_be32(f
);
2014 if (v
== QEMU_VM_FILE_VERSION_COMPAT
) {
2015 error_report("SaveVM v2 format is obsolete and don't work anymore");
2018 if (v
!= QEMU_VM_FILE_VERSION
) {
2019 error_report("Unsupported migration stream version");
2023 if (!savevm_state
.skip_configuration
|| enforce_config_section()) {
2024 if (qemu_get_byte(f
) != QEMU_VM_CONFIGURATION
) {
2025 error_report("Configuration section missing");
2028 ret
= vmstate_load_state(f
, &vmstate_configuration
, &savevm_state
, 0);
2035 ret
= qemu_loadvm_state_main(f
, mis
);
2036 qemu_event_set(&mis
->main_thread_load_event
);
2038 trace_qemu_loadvm_state_post_main(ret
);
2040 if (mis
->have_listen_thread
) {
2041 /* Listen thread still going, can't clean up yet */
2046 ret
= qemu_file_get_error(f
);
2050 * Try to read in the VMDESC section as well, so that dumping tools that
2051 * intercept our migration stream have the chance to see it.
2054 /* We've got to be careful; if we don't read the data and just shut the fd
2055 * then the sender can error if we close while it's still sending.
2056 * We also mustn't read data that isn't there; some transports (RDMA)
2057 * will stall waiting for that data when the source has already closed.
2059 if (ret
== 0 && should_send_vmdesc()) {
2062 uint8_t section_type
= qemu_get_byte(f
);
2064 if (section_type
!= QEMU_VM_VMDESCRIPTION
) {
2065 error_report("Expected vmdescription section, but got %d",
2068 * It doesn't seem worth failing at this point since
2069 * we apparently have an otherwise valid VM state
2072 buf
= g_malloc(0x1000);
2073 size
= qemu_get_be32(f
);
2076 uint32_t read_chunk
= MIN(size
, 0x1000);
2077 qemu_get_buffer(f
, buf
, read_chunk
);
2084 cpu_synchronize_all_post_init();
2089 int save_vmstate(const char *name
, Error
**errp
)
2091 BlockDriverState
*bs
, *bs1
;
2092 QEMUSnapshotInfo sn1
, *sn
= &sn1
, old_sn1
, *old_sn
= &old_sn1
;
2095 int saved_vm_running
;
2096 uint64_t vm_state_size
;
2099 AioContext
*aio_context
;
2101 if (!bdrv_all_can_snapshot(&bs
)) {
2102 error_setg(errp
, "Device '%s' is writable but does not support "
2103 "snapshots", bdrv_get_device_name(bs
));
2107 /* Delete old snapshots of the same name */
2109 ret
= bdrv_all_delete_snapshot(name
, &bs1
, errp
);
2111 error_prepend(errp
, "Error while deleting snapshot on device "
2112 "'%s': ", bdrv_get_device_name(bs1
));
2117 bs
= bdrv_all_find_vmstate_bs();
2119 error_setg(errp
, "No block device can accept snapshots");
2122 aio_context
= bdrv_get_aio_context(bs
);
2124 saved_vm_running
= runstate_is_running();
2126 ret
= global_state_store();
2128 error_setg(errp
, "Error saving global state");
2131 vm_stop(RUN_STATE_SAVE_VM
);
2133 aio_context_acquire(aio_context
);
2135 memset(sn
, 0, sizeof(*sn
));
2137 /* fill auxiliary fields */
2138 qemu_gettimeofday(&tv
);
2139 sn
->date_sec
= tv
.tv_sec
;
2140 sn
->date_nsec
= tv
.tv_usec
* 1000;
2141 sn
->vm_clock_nsec
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
2144 ret
= bdrv_snapshot_find(bs
, old_sn
, name
);
2146 pstrcpy(sn
->name
, sizeof(sn
->name
), old_sn
->name
);
2147 pstrcpy(sn
->id_str
, sizeof(sn
->id_str
), old_sn
->id_str
);
2149 pstrcpy(sn
->name
, sizeof(sn
->name
), name
);
2152 /* cast below needed for OpenBSD where tv_sec is still 'long' */
2153 localtime_r((const time_t *)&tv
.tv_sec
, &tm
);
2154 strftime(sn
->name
, sizeof(sn
->name
), "vm-%Y%m%d%H%M%S", &tm
);
2157 /* save the VM state */
2158 f
= qemu_fopen_bdrv(bs
, 1);
2160 error_setg(errp
, "Could not open VM state file");
2163 ret
= qemu_savevm_state(f
, errp
);
2164 vm_state_size
= qemu_ftell(f
);
2170 ret
= bdrv_all_create_snapshot(sn
, bs
, vm_state_size
, &bs
);
2172 error_setg(errp
, "Error while creating snapshot on '%s'",
2173 bdrv_get_device_name(bs
));
2180 aio_context_release(aio_context
);
2181 if (saved_vm_running
) {
2187 void qmp_xen_save_devices_state(const char *filename
, Error
**errp
)
2190 QIOChannelFile
*ioc
;
2191 int saved_vm_running
;
2194 saved_vm_running
= runstate_is_running();
2195 vm_stop(RUN_STATE_SAVE_VM
);
2196 global_state_store_running();
2198 ioc
= qio_channel_file_new_path(filename
, O_WRONLY
| O_CREAT
, 0660, errp
);
2202 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-save-state");
2203 f
= qemu_fopen_channel_output(QIO_CHANNEL(ioc
));
2204 ret
= qemu_save_device_state(f
);
2207 error_setg(errp
, QERR_IO_ERROR
);
2211 if (saved_vm_running
) {
2216 void qmp_xen_load_devices_state(const char *filename
, Error
**errp
)
2219 QIOChannelFile
*ioc
;
2222 /* Guest must be paused before loading the device state; the RAM state
2223 * will already have been loaded by xc
2225 if (runstate_is_running()) {
2226 error_setg(errp
, "Cannot update device state while vm is running");
2229 vm_stop(RUN_STATE_RESTORE_VM
);
2231 ioc
= qio_channel_file_new_path(filename
, O_RDONLY
| O_BINARY
, 0, errp
);
2235 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-load-state");
2236 f
= qemu_fopen_channel_input(QIO_CHANNEL(ioc
));
2238 ret
= qemu_loadvm_state(f
);
2241 error_setg(errp
, QERR_IO_ERROR
);
2243 migration_incoming_state_destroy();
2246 int load_vmstate(const char *name
, Error
**errp
)
2248 BlockDriverState
*bs
, *bs_vm_state
;
2249 QEMUSnapshotInfo sn
;
2252 AioContext
*aio_context
;
2253 MigrationIncomingState
*mis
= migration_incoming_get_current();
2255 if (!bdrv_all_can_snapshot(&bs
)) {
2257 "Device '%s' is writable but does not support snapshots",
2258 bdrv_get_device_name(bs
));
2261 ret
= bdrv_all_find_snapshot(name
, &bs
);
2264 "Device '%s' does not have the requested snapshot '%s'",
2265 bdrv_get_device_name(bs
), name
);
2269 bs_vm_state
= bdrv_all_find_vmstate_bs();
2271 error_setg(errp
, "No block device supports snapshots");
2274 aio_context
= bdrv_get_aio_context(bs_vm_state
);
2276 /* Don't even try to load empty VM states */
2277 aio_context_acquire(aio_context
);
2278 ret
= bdrv_snapshot_find(bs_vm_state
, &sn
, name
);
2279 aio_context_release(aio_context
);
2282 } else if (sn
.vm_state_size
== 0) {
2283 error_setg(errp
, "This is a disk-only snapshot. Revert to it "
2284 " offline using qemu-img");
2288 /* Flush all IO requests so they don't interfere with the new state. */
2291 ret
= bdrv_all_goto_snapshot(name
, &bs
);
2293 error_setg(errp
, "Error %d while activating snapshot '%s' on '%s'",
2294 ret
, name
, bdrv_get_device_name(bs
));
2298 /* restore the VM state */
2299 f
= qemu_fopen_bdrv(bs_vm_state
, 0);
2301 error_setg(errp
, "Could not open VM state file");
2305 qemu_system_reset(SHUTDOWN_CAUSE_NONE
);
2306 mis
->from_src_file
= f
;
2308 aio_context_acquire(aio_context
);
2309 ret
= qemu_loadvm_state(f
);
2311 aio_context_release(aio_context
);
2313 migration_incoming_state_destroy();
2315 error_setg(errp
, "Error %d while loading VM state", ret
);
2322 void vmstate_register_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2324 qemu_ram_set_idstr(mr
->ram_block
,
2325 memory_region_name(mr
), dev
);
2328 void vmstate_unregister_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2330 qemu_ram_unset_idstr(mr
->ram_block
);
2333 void vmstate_register_ram_global(MemoryRegion
*mr
)
2335 vmstate_register_ram(mr
, NULL
);
2338 bool vmstate_check_only_migratable(const VMStateDescription
*vmsd
)
2340 /* check needed if --only-migratable is specified */
2341 if (!only_migratable
) {
2345 return !(vmsd
&& vmsd
->unmigratable
);