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"
39 #include "postcopy-ram.h"
40 #include "qapi/qmp/qerror.h"
41 #include "qemu/error-report.h"
42 #include "qemu/queue.h"
43 #include "sysemu/cpus.h"
44 #include "exec/memory.h"
45 #include "exec/target_page.h"
46 #include "qmp-commands.h"
48 #include "qemu/bitops.h"
50 #include "block/snapshot.h"
51 #include "qemu/cutils.h"
52 #include "io/channel-buffer.h"
53 #include "io/channel-file.h"
56 #define ETH_P_RARP 0x8035
58 #define ARP_HTYPE_ETH 0x0001
59 #define ARP_PTYPE_IP 0x0800
60 #define ARP_OP_REQUEST_REV 0x3
62 const unsigned int postcopy_ram_discard_version
= 0;
64 static bool skip_section_footers
;
66 static struct mig_cmd_args
{
67 ssize_t len
; /* -1 = variable */
70 [MIG_CMD_INVALID
] = { .len
= -1, .name
= "INVALID" },
71 [MIG_CMD_OPEN_RETURN_PATH
] = { .len
= 0, .name
= "OPEN_RETURN_PATH" },
72 [MIG_CMD_PING
] = { .len
= sizeof(uint32_t), .name
= "PING" },
73 [MIG_CMD_POSTCOPY_ADVISE
] = { .len
= 16, .name
= "POSTCOPY_ADVISE" },
74 [MIG_CMD_POSTCOPY_LISTEN
] = { .len
= 0, .name
= "POSTCOPY_LISTEN" },
75 [MIG_CMD_POSTCOPY_RUN
] = { .len
= 0, .name
= "POSTCOPY_RUN" },
76 [MIG_CMD_POSTCOPY_RAM_DISCARD
] = {
77 .len
= -1, .name
= "POSTCOPY_RAM_DISCARD" },
78 [MIG_CMD_PACKAGED
] = { .len
= 4, .name
= "PACKAGED" },
79 [MIG_CMD_MAX
] = { .len
= -1, .name
= "MAX" },
82 static int announce_self_create(uint8_t *buf
,
85 /* Ethernet header. */
86 memset(buf
, 0xff, 6); /* destination MAC addr */
87 memcpy(buf
+ 6, mac_addr
, 6); /* source MAC addr */
88 *(uint16_t *)(buf
+ 12) = htons(ETH_P_RARP
); /* ethertype */
91 *(uint16_t *)(buf
+ 14) = htons(ARP_HTYPE_ETH
); /* hardware addr space */
92 *(uint16_t *)(buf
+ 16) = htons(ARP_PTYPE_IP
); /* protocol addr space */
93 *(buf
+ 18) = 6; /* hardware addr length (ethernet) */
94 *(buf
+ 19) = 4; /* protocol addr length (IPv4) */
95 *(uint16_t *)(buf
+ 20) = htons(ARP_OP_REQUEST_REV
); /* opcode */
96 memcpy(buf
+ 22, mac_addr
, 6); /* source hw addr */
97 memset(buf
+ 28, 0x00, 4); /* source protocol addr */
98 memcpy(buf
+ 32, mac_addr
, 6); /* target hw addr */
99 memset(buf
+ 38, 0x00, 4); /* target protocol addr */
101 /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
102 memset(buf
+ 42, 0x00, 18);
104 return 60; /* len (FCS will be added by hardware) */
107 static void qemu_announce_self_iter(NICState
*nic
, void *opaque
)
112 trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic
->conf
->macaddr
));
113 len
= announce_self_create(buf
, nic
->conf
->macaddr
.a
);
115 qemu_send_packet_raw(qemu_get_queue(nic
), buf
, len
);
119 static void qemu_announce_self_once(void *opaque
)
121 static int count
= SELF_ANNOUNCE_ROUNDS
;
122 QEMUTimer
*timer
= *(QEMUTimer
**)opaque
;
124 qemu_foreach_nic(qemu_announce_self_iter
, NULL
);
127 /* delay 50ms, 150ms, 250ms, ... */
128 timer_mod(timer
, qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) +
129 self_announce_delay(count
));
136 void qemu_announce_self(void)
138 static QEMUTimer
*timer
;
139 timer
= timer_new_ms(QEMU_CLOCK_REALTIME
, qemu_announce_self_once
, &timer
);
140 qemu_announce_self_once(&timer
);
143 /***********************************************************/
144 /* savevm/loadvm support */
146 static ssize_t
block_writev_buffer(void *opaque
, struct iovec
*iov
, int iovcnt
,
152 qemu_iovec_init_external(&qiov
, iov
, iovcnt
);
153 ret
= bdrv_writev_vmstate(opaque
, &qiov
, pos
);
161 static ssize_t
block_get_buffer(void *opaque
, uint8_t *buf
, int64_t pos
,
164 return bdrv_load_vmstate(opaque
, buf
, pos
, size
);
167 static int bdrv_fclose(void *opaque
)
169 return bdrv_flush(opaque
);
172 static const QEMUFileOps bdrv_read_ops
= {
173 .get_buffer
= block_get_buffer
,
177 static const QEMUFileOps bdrv_write_ops
= {
178 .writev_buffer
= block_writev_buffer
,
182 static QEMUFile
*qemu_fopen_bdrv(BlockDriverState
*bs
, int is_writable
)
185 return qemu_fopen_ops(bs
, &bdrv_write_ops
);
187 return qemu_fopen_ops(bs
, &bdrv_read_ops
);
191 /* QEMUFile timer support.
192 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
195 void timer_put(QEMUFile
*f
, QEMUTimer
*ts
)
197 uint64_t expire_time
;
199 expire_time
= timer_expire_time_ns(ts
);
200 qemu_put_be64(f
, expire_time
);
203 void timer_get(QEMUFile
*f
, QEMUTimer
*ts
)
205 uint64_t expire_time
;
207 expire_time
= qemu_get_be64(f
);
208 if (expire_time
!= -1) {
209 timer_mod_ns(ts
, expire_time
);
216 /* VMState timer support.
217 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
220 static int get_timer(QEMUFile
*f
, void *pv
, size_t size
, VMStateField
*field
)
227 static int put_timer(QEMUFile
*f
, void *pv
, size_t size
, VMStateField
*field
,
236 const VMStateInfo vmstate_info_timer
= {
243 typedef struct CompatEntry
{
248 typedef struct SaveStateEntry
{
249 QTAILQ_ENTRY(SaveStateEntry
) entry
;
256 const VMStateDescription
*vmsd
;
262 typedef struct SaveState
{
263 QTAILQ_HEAD(, SaveStateEntry
) handlers
;
264 int global_section_id
;
265 bool skip_configuration
;
268 uint32_t target_page_bits
;
271 static SaveState savevm_state
= {
272 .handlers
= QTAILQ_HEAD_INITIALIZER(savevm_state
.handlers
),
273 .global_section_id
= 0,
274 .skip_configuration
= false,
277 void savevm_skip_configuration(void)
279 savevm_state
.skip_configuration
= true;
283 static void configuration_pre_save(void *opaque
)
285 SaveState
*state
= opaque
;
286 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
288 state
->len
= strlen(current_name
);
289 state
->name
= current_name
;
290 state
->target_page_bits
= qemu_target_page_bits();
293 static int configuration_pre_load(void *opaque
)
295 SaveState
*state
= opaque
;
297 /* If there is no target-page-bits subsection it means the source
298 * predates the variable-target-page-bits support and is using the
299 * minimum possible value for this CPU.
301 state
->target_page_bits
= qemu_target_page_bits_min();
305 static int configuration_post_load(void *opaque
, int version_id
)
307 SaveState
*state
= opaque
;
308 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
310 if (strncmp(state
->name
, current_name
, state
->len
) != 0) {
311 error_report("Machine type received is '%.*s' and local is '%s'",
312 (int) state
->len
, state
->name
, current_name
);
316 if (state
->target_page_bits
!= qemu_target_page_bits()) {
317 error_report("Received TARGET_PAGE_BITS is %d but local is %d",
318 state
->target_page_bits
, qemu_target_page_bits());
325 /* The target-page-bits subsection is present only if the
326 * target page size is not the same as the default (ie the
327 * minimum page size for a variable-page-size guest CPU).
328 * If it is present then it contains the actual target page
329 * bits for the machine, and migration will fail if the
330 * two ends don't agree about it.
332 static bool vmstate_target_page_bits_needed(void *opaque
)
334 return qemu_target_page_bits()
335 > qemu_target_page_bits_min();
338 static const VMStateDescription vmstate_target_page_bits
= {
339 .name
= "configuration/target-page-bits",
341 .minimum_version_id
= 1,
342 .needed
= vmstate_target_page_bits_needed
,
343 .fields
= (VMStateField
[]) {
344 VMSTATE_UINT32(target_page_bits
, SaveState
),
345 VMSTATE_END_OF_LIST()
349 static const VMStateDescription vmstate_configuration
= {
350 .name
= "configuration",
352 .pre_load
= configuration_pre_load
,
353 .post_load
= configuration_post_load
,
354 .pre_save
= configuration_pre_save
,
355 .fields
= (VMStateField
[]) {
356 VMSTATE_UINT32(len
, SaveState
),
357 VMSTATE_VBUFFER_ALLOC_UINT32(name
, SaveState
, 0, NULL
, len
),
358 VMSTATE_END_OF_LIST()
360 .subsections
= (const VMStateDescription
*[]) {
361 &vmstate_target_page_bits
,
366 static void dump_vmstate_vmsd(FILE *out_file
,
367 const VMStateDescription
*vmsd
, int indent
,
370 static void dump_vmstate_vmsf(FILE *out_file
, const VMStateField
*field
,
373 fprintf(out_file
, "%*s{\n", indent
, "");
375 fprintf(out_file
, "%*s\"field\": \"%s\",\n", indent
, "", field
->name
);
376 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
378 fprintf(out_file
, "%*s\"field_exists\": %s,\n", indent
, "",
379 field
->field_exists
? "true" : "false");
380 fprintf(out_file
, "%*s\"size\": %zu", indent
, "", field
->size
);
381 if (field
->vmsd
!= NULL
) {
382 fprintf(out_file
, ",\n");
383 dump_vmstate_vmsd(out_file
, field
->vmsd
, indent
, false);
385 fprintf(out_file
, "\n%*s}", indent
- 2, "");
388 static void dump_vmstate_vmss(FILE *out_file
,
389 const VMStateDescription
**subsection
,
392 if (*subsection
!= NULL
) {
393 dump_vmstate_vmsd(out_file
, *subsection
, indent
, true);
397 static void dump_vmstate_vmsd(FILE *out_file
,
398 const VMStateDescription
*vmsd
, int indent
,
402 fprintf(out_file
, "%*s{\n", indent
, "");
404 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", "Description");
407 fprintf(out_file
, "%*s\"name\": \"%s\",\n", indent
, "", vmsd
->name
);
408 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
410 fprintf(out_file
, "%*s\"minimum_version_id\": %d", indent
, "",
411 vmsd
->minimum_version_id
);
412 if (vmsd
->fields
!= NULL
) {
413 const VMStateField
*field
= vmsd
->fields
;
416 fprintf(out_file
, ",\n%*s\"Fields\": [\n", indent
, "");
418 while (field
->name
!= NULL
) {
419 if (field
->flags
& VMS_MUST_EXIST
) {
420 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
425 fprintf(out_file
, ",\n");
427 dump_vmstate_vmsf(out_file
, field
, indent
+ 2);
431 fprintf(out_file
, "\n%*s]", indent
, "");
433 if (vmsd
->subsections
!= NULL
) {
434 const VMStateDescription
**subsection
= vmsd
->subsections
;
437 fprintf(out_file
, ",\n%*s\"Subsections\": [\n", indent
, "");
439 while (*subsection
!= NULL
) {
441 fprintf(out_file
, ",\n");
443 dump_vmstate_vmss(out_file
, subsection
, indent
+ 2);
447 fprintf(out_file
, "\n%*s]", indent
, "");
449 fprintf(out_file
, "\n%*s}", indent
- 2, "");
452 static void dump_machine_type(FILE *out_file
)
456 mc
= MACHINE_GET_CLASS(current_machine
);
458 fprintf(out_file
, " \"vmschkmachine\": {\n");
459 fprintf(out_file
, " \"Name\": \"%s\"\n", mc
->name
);
460 fprintf(out_file
, " },\n");
463 void dump_vmstate_json_to_file(FILE *out_file
)
468 fprintf(out_file
, "{\n");
469 dump_machine_type(out_file
);
472 list
= object_class_get_list(TYPE_DEVICE
, true);
473 for (elt
= list
; elt
; elt
= elt
->next
) {
474 DeviceClass
*dc
= OBJECT_CLASS_CHECK(DeviceClass
, elt
->data
,
484 fprintf(out_file
, ",\n");
486 name
= object_class_get_name(OBJECT_CLASS(dc
));
487 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", name
);
489 fprintf(out_file
, "%*s\"Name\": \"%s\",\n", indent
, "", name
);
490 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
491 dc
->vmsd
->version_id
);
492 fprintf(out_file
, "%*s\"minimum_version_id\": %d,\n", indent
, "",
493 dc
->vmsd
->minimum_version_id
);
495 dump_vmstate_vmsd(out_file
, dc
->vmsd
, indent
, false);
497 fprintf(out_file
, "\n%*s}", indent
- 2, "");
500 fprintf(out_file
, "\n}\n");
504 static int calculate_new_instance_id(const char *idstr
)
509 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
510 if (strcmp(idstr
, se
->idstr
) == 0
511 && instance_id
<= se
->instance_id
) {
512 instance_id
= se
->instance_id
+ 1;
518 static int calculate_compat_instance_id(const char *idstr
)
523 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
528 if (strcmp(idstr
, se
->compat
->idstr
) == 0
529 && instance_id
<= se
->compat
->instance_id
) {
530 instance_id
= se
->compat
->instance_id
+ 1;
536 static inline MigrationPriority
save_state_priority(SaveStateEntry
*se
)
539 return se
->vmsd
->priority
;
541 return MIG_PRI_DEFAULT
;
544 static void savevm_state_handler_insert(SaveStateEntry
*nse
)
546 MigrationPriority priority
= save_state_priority(nse
);
549 assert(priority
<= MIG_PRI_MAX
);
551 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
552 if (save_state_priority(se
) < priority
) {
558 QTAILQ_INSERT_BEFORE(se
, nse
, entry
);
560 QTAILQ_INSERT_TAIL(&savevm_state
.handlers
, nse
, entry
);
564 /* TODO: Individual devices generally have very little idea about the rest
565 of the system, so instance_id should be removed/replaced.
566 Meanwhile pass -1 as instance_id if you do not already have a clearly
567 distinguishing id for all instances of your device class. */
568 int register_savevm_live(DeviceState
*dev
,
577 se
= g_new0(SaveStateEntry
, 1);
578 se
->version_id
= version_id
;
579 se
->section_id
= savevm_state
.global_section_id
++;
583 /* if this is a live_savem then set is_ram */
584 if (ops
->save_live_setup
!= NULL
) {
589 char *id
= qdev_get_dev_path(dev
);
591 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
593 error_report("Path too long for VMState (%s)", id
);
601 se
->compat
= g_new0(CompatEntry
, 1);
602 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), idstr
);
603 se
->compat
->instance_id
= instance_id
== -1 ?
604 calculate_compat_instance_id(idstr
) : instance_id
;
608 pstrcat(se
->idstr
, sizeof(se
->idstr
), idstr
);
610 if (instance_id
== -1) {
611 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
613 se
->instance_id
= instance_id
;
615 assert(!se
->compat
|| se
->instance_id
== 0);
616 savevm_state_handler_insert(se
);
620 int register_savevm(DeviceState
*dev
,
624 SaveStateHandler
*save_state
,
625 LoadStateHandler
*load_state
,
628 SaveVMHandlers
*ops
= g_new0(SaveVMHandlers
, 1);
629 ops
->save_state
= save_state
;
630 ops
->load_state
= load_state
;
631 return register_savevm_live(dev
, idstr
, instance_id
, version_id
,
635 void unregister_savevm(DeviceState
*dev
, const char *idstr
, void *opaque
)
637 SaveStateEntry
*se
, *new_se
;
641 char *path
= qdev_get_dev_path(dev
);
643 pstrcpy(id
, sizeof(id
), path
);
644 pstrcat(id
, sizeof(id
), "/");
648 pstrcat(id
, sizeof(id
), idstr
);
650 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
651 if (strcmp(se
->idstr
, id
) == 0 && se
->opaque
== opaque
) {
652 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
660 int vmstate_register_with_alias_id(DeviceState
*dev
, int instance_id
,
661 const VMStateDescription
*vmsd
,
662 void *opaque
, int alias_id
,
663 int required_for_version
,
668 /* If this triggers, alias support can be dropped for the vmsd. */
669 assert(alias_id
== -1 || required_for_version
>= vmsd
->minimum_version_id
);
671 se
= g_new0(SaveStateEntry
, 1);
672 se
->version_id
= vmsd
->version_id
;
673 se
->section_id
= savevm_state
.global_section_id
++;
676 se
->alias_id
= alias_id
;
679 char *id
= qdev_get_dev_path(dev
);
681 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
683 error_setg(errp
, "Path too long for VMState (%s)", id
);
691 se
->compat
= g_new0(CompatEntry
, 1);
692 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), vmsd
->name
);
693 se
->compat
->instance_id
= instance_id
== -1 ?
694 calculate_compat_instance_id(vmsd
->name
) : instance_id
;
698 pstrcat(se
->idstr
, sizeof(se
->idstr
), vmsd
->name
);
700 if (instance_id
== -1) {
701 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
703 se
->instance_id
= instance_id
;
705 assert(!se
->compat
|| se
->instance_id
== 0);
706 savevm_state_handler_insert(se
);
710 void vmstate_unregister(DeviceState
*dev
, const VMStateDescription
*vmsd
,
713 SaveStateEntry
*se
, *new_se
;
715 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
716 if (se
->vmsd
== vmsd
&& se
->opaque
== opaque
) {
717 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
724 static int vmstate_load(QEMUFile
*f
, SaveStateEntry
*se
, int version_id
)
726 trace_vmstate_load(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
727 if (!se
->vmsd
) { /* Old style */
728 return se
->ops
->load_state(f
, se
->opaque
, version_id
);
730 return vmstate_load_state(f
, se
->vmsd
, se
->opaque
, version_id
);
733 static void vmstate_save_old_style(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
735 int64_t old_offset
, size
;
737 old_offset
= qemu_ftell_fast(f
);
738 se
->ops
->save_state(f
, se
->opaque
);
739 size
= qemu_ftell_fast(f
) - old_offset
;
742 json_prop_int(vmdesc
, "size", size
);
743 json_start_array(vmdesc
, "fields");
744 json_start_object(vmdesc
, NULL
);
745 json_prop_str(vmdesc
, "name", "data");
746 json_prop_int(vmdesc
, "size", size
);
747 json_prop_str(vmdesc
, "type", "buffer");
748 json_end_object(vmdesc
);
749 json_end_array(vmdesc
);
753 static void vmstate_save(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
755 trace_vmstate_save(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
757 vmstate_save_old_style(f
, se
, vmdesc
);
760 vmstate_save_state(f
, se
->vmsd
, se
->opaque
, vmdesc
);
763 void savevm_skip_section_footers(void)
765 skip_section_footers
= true;
769 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
771 static void save_section_header(QEMUFile
*f
, SaveStateEntry
*se
,
772 uint8_t section_type
)
774 qemu_put_byte(f
, section_type
);
775 qemu_put_be32(f
, se
->section_id
);
777 if (section_type
== QEMU_VM_SECTION_FULL
||
778 section_type
== QEMU_VM_SECTION_START
) {
780 size_t len
= strlen(se
->idstr
);
781 qemu_put_byte(f
, len
);
782 qemu_put_buffer(f
, (uint8_t *)se
->idstr
, len
);
784 qemu_put_be32(f
, se
->instance_id
);
785 qemu_put_be32(f
, se
->version_id
);
790 * Write a footer onto device sections that catches cases misformatted device
793 static void save_section_footer(QEMUFile
*f
, SaveStateEntry
*se
)
795 if (!skip_section_footers
) {
796 qemu_put_byte(f
, QEMU_VM_SECTION_FOOTER
);
797 qemu_put_be32(f
, se
->section_id
);
802 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
803 * command and associated data.
805 * @f: File to send command on
806 * @command: Command type to send
807 * @len: Length of associated data
808 * @data: Data associated with command.
810 void qemu_savevm_command_send(QEMUFile
*f
,
811 enum qemu_vm_cmd command
,
815 trace_savevm_command_send(command
, len
);
816 qemu_put_byte(f
, QEMU_VM_COMMAND
);
817 qemu_put_be16(f
, (uint16_t)command
);
818 qemu_put_be16(f
, len
);
819 qemu_put_buffer(f
, data
, len
);
823 void qemu_savevm_send_ping(QEMUFile
*f
, uint32_t value
)
827 trace_savevm_send_ping(value
);
828 buf
= cpu_to_be32(value
);
829 qemu_savevm_command_send(f
, MIG_CMD_PING
, sizeof(value
), (uint8_t *)&buf
);
832 void qemu_savevm_send_open_return_path(QEMUFile
*f
)
834 trace_savevm_send_open_return_path();
835 qemu_savevm_command_send(f
, MIG_CMD_OPEN_RETURN_PATH
, 0, NULL
);
838 /* We have a buffer of data to send; we don't want that all to be loaded
839 * by the command itself, so the command contains just the length of the
840 * extra buffer that we then send straight after it.
841 * TODO: Must be a better way to organise that
847 int qemu_savevm_send_packaged(QEMUFile
*f
, const uint8_t *buf
, size_t len
)
851 if (len
> MAX_VM_CMD_PACKAGED_SIZE
) {
852 error_report("%s: Unreasonably large packaged state: %zu",
857 tmp
= cpu_to_be32(len
);
859 trace_qemu_savevm_send_packaged();
860 qemu_savevm_command_send(f
, MIG_CMD_PACKAGED
, 4, (uint8_t *)&tmp
);
862 qemu_put_buffer(f
, buf
, len
);
867 /* Send prior to any postcopy transfer */
868 void qemu_savevm_send_postcopy_advise(QEMUFile
*f
)
871 tmp
[0] = cpu_to_be64(ram_pagesize_summary());
872 tmp
[1] = cpu_to_be64(qemu_target_page_size());
874 trace_qemu_savevm_send_postcopy_advise();
875 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_ADVISE
, 16, (uint8_t *)tmp
);
878 /* Sent prior to starting the destination running in postcopy, discard pages
879 * that have already been sent but redirtied on the source.
880 * CMD_POSTCOPY_RAM_DISCARD consist of:
882 * byte Length of name field (not including 0)
883 * n x byte RAM block name
884 * byte 0 terminator (just for safety)
885 * n x Byte ranges within the named RAMBlock
886 * be64 Start of the range
889 * name: RAMBlock name that these entries are part of
890 * len: Number of page entries
891 * start_list: 'len' addresses
892 * length_list: 'len' addresses
895 void qemu_savevm_send_postcopy_ram_discard(QEMUFile
*f
, const char *name
,
897 uint64_t *start_list
,
898 uint64_t *length_list
)
903 size_t name_len
= strlen(name
);
905 trace_qemu_savevm_send_postcopy_ram_discard(name
, len
);
906 assert(name_len
< 256);
907 buf
= g_malloc0(1 + 1 + name_len
+ 1 + (8 + 8) * len
);
908 buf
[0] = postcopy_ram_discard_version
;
910 memcpy(buf
+ 2, name
, name_len
);
911 tmplen
= 2 + name_len
;
912 buf
[tmplen
++] = '\0';
914 for (t
= 0; t
< len
; t
++) {
915 stq_be_p(buf
+ tmplen
, start_list
[t
]);
917 stq_be_p(buf
+ tmplen
, length_list
[t
]);
920 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RAM_DISCARD
, tmplen
, buf
);
924 /* Get the destination into a state where it can receive postcopy data. */
925 void qemu_savevm_send_postcopy_listen(QEMUFile
*f
)
927 trace_savevm_send_postcopy_listen();
928 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_LISTEN
, 0, NULL
);
931 /* Kick the destination into running */
932 void qemu_savevm_send_postcopy_run(QEMUFile
*f
)
934 trace_savevm_send_postcopy_run();
935 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RUN
, 0, NULL
);
938 bool qemu_savevm_state_blocked(Error
**errp
)
942 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
943 if (se
->vmsd
&& se
->vmsd
->unmigratable
) {
944 error_setg(errp
, "State blocked by non-migratable device '%s'",
952 static bool enforce_config_section(void)
954 MachineState
*machine
= MACHINE(qdev_get_machine());
955 return machine
->enforce_config_section
;
958 void qemu_savevm_state_header(QEMUFile
*f
)
960 trace_savevm_state_header();
961 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
962 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
964 if (!savevm_state
.skip_configuration
|| enforce_config_section()) {
965 qemu_put_byte(f
, QEMU_VM_CONFIGURATION
);
966 vmstate_save_state(f
, &vmstate_configuration
, &savevm_state
, 0);
971 void qemu_savevm_state_begin(QEMUFile
*f
)
976 trace_savevm_state_begin();
977 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
978 if (!se
->ops
|| !se
->ops
->save_live_setup
) {
981 if (se
->ops
&& se
->ops
->is_active
) {
982 if (!se
->ops
->is_active(se
->opaque
)) {
986 save_section_header(f
, se
, QEMU_VM_SECTION_START
);
988 ret
= se
->ops
->save_live_setup(f
, se
->opaque
);
989 save_section_footer(f
, se
);
991 qemu_file_set_error(f
, ret
);
998 * this function has three return values:
999 * negative: there was one error, and we have -errno.
1000 * 0 : We haven't finished, caller have to go again
1001 * 1 : We have finished, we can go to complete phase
1003 int qemu_savevm_state_iterate(QEMUFile
*f
, bool postcopy
)
1008 trace_savevm_state_iterate();
1009 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1010 if (!se
->ops
|| !se
->ops
->save_live_iterate
) {
1013 if (se
->ops
&& se
->ops
->is_active
) {
1014 if (!se
->ops
->is_active(se
->opaque
)) {
1019 * In the postcopy phase, any device that doesn't know how to
1020 * do postcopy should have saved it's state in the _complete
1021 * call that's already run, it might get confused if we call
1022 * iterate afterwards.
1024 if (postcopy
&& !se
->ops
->save_live_complete_postcopy
) {
1027 if (qemu_file_rate_limit(f
)) {
1030 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1032 save_section_header(f
, se
, QEMU_VM_SECTION_PART
);
1034 ret
= se
->ops
->save_live_iterate(f
, se
->opaque
);
1035 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1036 save_section_footer(f
, se
);
1039 qemu_file_set_error(f
, ret
);
1042 /* Do not proceed to the next vmstate before this one reported
1043 completion of the current stage. This serializes the migration
1044 and reduces the probability that a faster changing state is
1045 synchronized over and over again. */
1052 static bool should_send_vmdesc(void)
1054 MachineState
*machine
= MACHINE(qdev_get_machine());
1055 bool in_postcopy
= migration_in_postcopy();
1056 return !machine
->suppress_vmdesc
&& !in_postcopy
;
1060 * Calls the save_live_complete_postcopy methods
1061 * causing the last few pages to be sent immediately and doing any associated
1063 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
1064 * all the other devices, but that happens at the point we switch to postcopy.
1066 void qemu_savevm_state_complete_postcopy(QEMUFile
*f
)
1071 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1072 if (!se
->ops
|| !se
->ops
->save_live_complete_postcopy
) {
1075 if (se
->ops
&& se
->ops
->is_active
) {
1076 if (!se
->ops
->is_active(se
->opaque
)) {
1080 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1082 qemu_put_byte(f
, QEMU_VM_SECTION_END
);
1083 qemu_put_be32(f
, se
->section_id
);
1085 ret
= se
->ops
->save_live_complete_postcopy(f
, se
->opaque
);
1086 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1087 save_section_footer(f
, se
);
1089 qemu_file_set_error(f
, ret
);
1094 qemu_put_byte(f
, QEMU_VM_EOF
);
1098 void qemu_savevm_state_complete_precopy(QEMUFile
*f
, bool iterable_only
)
1104 bool in_postcopy
= migration_in_postcopy();
1106 trace_savevm_state_complete_precopy();
1108 cpu_synchronize_all_states();
1110 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1112 (in_postcopy
&& se
->ops
->save_live_complete_postcopy
) ||
1113 (in_postcopy
&& !iterable_only
) ||
1114 !se
->ops
->save_live_complete_precopy
) {
1118 if (se
->ops
&& se
->ops
->is_active
) {
1119 if (!se
->ops
->is_active(se
->opaque
)) {
1123 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1125 save_section_header(f
, se
, QEMU_VM_SECTION_END
);
1127 ret
= se
->ops
->save_live_complete_precopy(f
, se
->opaque
);
1128 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1129 save_section_footer(f
, se
);
1131 qemu_file_set_error(f
, ret
);
1136 if (iterable_only
) {
1140 vmdesc
= qjson_new();
1141 json_prop_int(vmdesc
, "page_size", qemu_target_page_size());
1142 json_start_array(vmdesc
, "devices");
1143 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1145 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1148 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1149 trace_savevm_section_skip(se
->idstr
, se
->section_id
);
1153 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1155 json_start_object(vmdesc
, NULL
);
1156 json_prop_str(vmdesc
, "name", se
->idstr
);
1157 json_prop_int(vmdesc
, "instance_id", se
->instance_id
);
1159 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1160 vmstate_save(f
, se
, vmdesc
);
1161 trace_savevm_section_end(se
->idstr
, se
->section_id
, 0);
1162 save_section_footer(f
, se
);
1164 json_end_object(vmdesc
);
1168 /* Postcopy stream will still be going */
1169 qemu_put_byte(f
, QEMU_VM_EOF
);
1172 json_end_array(vmdesc
);
1173 qjson_finish(vmdesc
);
1174 vmdesc_len
= strlen(qjson_get_str(vmdesc
));
1176 if (should_send_vmdesc()) {
1177 qemu_put_byte(f
, QEMU_VM_VMDESCRIPTION
);
1178 qemu_put_be32(f
, vmdesc_len
);
1179 qemu_put_buffer(f
, (uint8_t *)qjson_get_str(vmdesc
), vmdesc_len
);
1181 qjson_destroy(vmdesc
);
1186 /* Give an estimate of the amount left to be transferred,
1187 * the result is split into the amount for units that can and
1188 * for units that can't do postcopy.
1190 void qemu_savevm_state_pending(QEMUFile
*f
, uint64_t threshold_size
,
1191 uint64_t *res_non_postcopiable
,
1192 uint64_t *res_postcopiable
)
1196 *res_non_postcopiable
= 0;
1197 *res_postcopiable
= 0;
1200 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1201 if (!se
->ops
|| !se
->ops
->save_live_pending
) {
1204 if (se
->ops
&& se
->ops
->is_active
) {
1205 if (!se
->ops
->is_active(se
->opaque
)) {
1209 se
->ops
->save_live_pending(f
, se
->opaque
, threshold_size
,
1210 res_non_postcopiable
, res_postcopiable
);
1214 void qemu_savevm_state_cleanup(void)
1218 trace_savevm_state_cleanup();
1219 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1220 if (se
->ops
&& se
->ops
->cleanup
) {
1221 se
->ops
->cleanup(se
->opaque
);
1226 static int qemu_savevm_state(QEMUFile
*f
, Error
**errp
)
1229 MigrationState
*ms
= migrate_init();
1230 MigrationStatus status
;
1231 ms
->to_dst_file
= f
;
1233 if (migration_is_blocked(errp
)) {
1238 if (migrate_use_block()) {
1239 error_setg(errp
, "Block migration and snapshots are incompatible");
1244 qemu_mutex_unlock_iothread();
1245 qemu_savevm_state_header(f
);
1246 qemu_savevm_state_begin(f
);
1247 qemu_mutex_lock_iothread();
1249 while (qemu_file_get_error(f
) == 0) {
1250 if (qemu_savevm_state_iterate(f
, false) > 0) {
1255 ret
= qemu_file_get_error(f
);
1257 qemu_savevm_state_complete_precopy(f
, false);
1258 ret
= qemu_file_get_error(f
);
1260 qemu_savevm_state_cleanup();
1262 error_setg_errno(errp
, -ret
, "Error while writing VM state");
1267 status
= MIGRATION_STATUS_FAILED
;
1269 status
= MIGRATION_STATUS_COMPLETED
;
1271 migrate_set_state(&ms
->state
, MIGRATION_STATUS_SETUP
, status
);
1273 /* f is outer parameter, it should not stay in global migration state after
1274 * this function finished */
1275 ms
->to_dst_file
= NULL
;
1280 static int qemu_save_device_state(QEMUFile
*f
)
1284 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
1285 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
1287 cpu_synchronize_all_states();
1289 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1293 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1296 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1300 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1302 vmstate_save(f
, se
, NULL
);
1304 save_section_footer(f
, se
);
1307 qemu_put_byte(f
, QEMU_VM_EOF
);
1309 return qemu_file_get_error(f
);
1312 static SaveStateEntry
*find_se(const char *idstr
, int instance_id
)
1316 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1317 if (!strcmp(se
->idstr
, idstr
) &&
1318 (instance_id
== se
->instance_id
||
1319 instance_id
== se
->alias_id
))
1321 /* Migrating from an older version? */
1322 if (strstr(se
->idstr
, idstr
) && se
->compat
) {
1323 if (!strcmp(se
->compat
->idstr
, idstr
) &&
1324 (instance_id
== se
->compat
->instance_id
||
1325 instance_id
== se
->alias_id
))
1332 enum LoadVMExitCodes
{
1333 /* Allow a command to quit all layers of nested loadvm loops */
1337 static int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
);
1339 /* ------ incoming postcopy messages ------ */
1340 /* 'advise' arrives before any transfers just to tell us that a postcopy
1341 * *might* happen - it might be skipped if precopy transferred everything
1344 static int loadvm_postcopy_handle_advise(MigrationIncomingState
*mis
)
1346 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1347 uint64_t remote_pagesize_summary
, local_pagesize_summary
, remote_tps
;
1349 trace_loadvm_postcopy_handle_advise();
1350 if (ps
!= POSTCOPY_INCOMING_NONE
) {
1351 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps
);
1355 if (!postcopy_ram_supported_by_host()) {
1356 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
1360 remote_pagesize_summary
= qemu_get_be64(mis
->from_src_file
);
1361 local_pagesize_summary
= ram_pagesize_summary();
1363 if (remote_pagesize_summary
!= local_pagesize_summary
) {
1365 * This detects two potential causes of mismatch:
1366 * a) A mismatch in host page sizes
1367 * Some combinations of mismatch are probably possible but it gets
1368 * a bit more complicated. In particular we need to place whole
1369 * host pages on the dest at once, and we need to ensure that we
1370 * handle dirtying to make sure we never end up sending part of
1371 * a hostpage on it's own.
1372 * b) The use of different huge page sizes on source/destination
1373 * a more fine grain test is performed during RAM block migration
1374 * but this test here causes a nice early clear failure, and
1375 * also fails when passed to an older qemu that doesn't
1378 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
1380 remote_pagesize_summary
, local_pagesize_summary
);
1384 remote_tps
= qemu_get_be64(mis
->from_src_file
);
1385 if (remote_tps
!= qemu_target_page_size()) {
1387 * Again, some differences could be dealt with, but for now keep it
1390 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
1391 (int)remote_tps
, qemu_target_page_size());
1395 if (ram_postcopy_incoming_init(mis
)) {
1399 postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1404 /* After postcopy we will be told to throw some pages away since they're
1405 * dirty and will have to be demand fetched. Must happen before CPU is
1407 * There can be 0..many of these messages, each encoding multiple pages.
1409 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState
*mis
,
1414 PostcopyState ps
= postcopy_state_get();
1416 trace_loadvm_postcopy_ram_handle_discard();
1419 case POSTCOPY_INCOMING_ADVISE
:
1421 tmp
= postcopy_ram_prepare_discard(mis
);
1427 case POSTCOPY_INCOMING_DISCARD
:
1428 /* Expected state */
1432 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
1436 /* We're expecting a
1438 * a RAM ID string (length byte, name, 0 term)
1439 * then at least 1 16 byte chunk
1441 if (len
< (1 + 1 + 1 + 1 + 2 * 8)) {
1442 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1446 tmp
= qemu_get_byte(mis
->from_src_file
);
1447 if (tmp
!= postcopy_ram_discard_version
) {
1448 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp
);
1452 if (!qemu_get_counted_string(mis
->from_src_file
, ramid
)) {
1453 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
1456 tmp
= qemu_get_byte(mis
->from_src_file
);
1458 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp
);
1462 len
-= 3 + strlen(ramid
);
1464 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1467 trace_loadvm_postcopy_ram_handle_discard_header(ramid
, len
);
1469 uint64_t start_addr
, block_length
;
1470 start_addr
= qemu_get_be64(mis
->from_src_file
);
1471 block_length
= qemu_get_be64(mis
->from_src_file
);
1474 int ret
= ram_discard_range(ramid
, start_addr
, block_length
);
1479 trace_loadvm_postcopy_ram_handle_discard_end();
1485 * Triggered by a postcopy_listen command; this thread takes over reading
1486 * the input stream, leaving the main thread free to carry on loading the rest
1487 * of the device state (from RAM).
1488 * (TODO:This could do with being in a postcopy file - but there again it's
1489 * just another input loop, not that postcopy specific)
1491 static void *postcopy_ram_listen_thread(void *opaque
)
1493 QEMUFile
*f
= opaque
;
1494 MigrationIncomingState
*mis
= migration_incoming_get_current();
1497 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
1498 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1499 qemu_sem_post(&mis
->listen_thread_sem
);
1500 trace_postcopy_ram_listen_thread_start();
1503 * Because we're a thread and not a coroutine we can't yield
1504 * in qemu_file, and thus we must be blocking now.
1506 qemu_file_set_blocking(f
, true);
1507 load_res
= qemu_loadvm_state_main(f
, mis
);
1508 /* And non-blocking again so we don't block in any cleanup */
1509 qemu_file_set_blocking(f
, false);
1511 trace_postcopy_ram_listen_thread_exit();
1513 error_report("%s: loadvm failed: %d", __func__
, load_res
);
1514 qemu_file_set_error(f
, load_res
);
1515 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1516 MIGRATION_STATUS_FAILED
);
1519 * This looks good, but it's possible that the device loading in the
1520 * main thread hasn't finished yet, and so we might not be in 'RUN'
1521 * state yet; wait for the end of the main thread.
1523 qemu_event_wait(&mis
->main_thread_load_event
);
1525 postcopy_ram_incoming_cleanup(mis
);
1529 * If something went wrong then we have a bad state so exit;
1530 * depending how far we got it might be possible at this point
1531 * to leave the guest running and fire MCEs for pages that never
1532 * arrived as a desperate recovery step.
1537 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1538 MIGRATION_STATUS_COMPLETED
);
1540 * If everything has worked fine, then the main thread has waited
1541 * for us to start, and we're the last use of the mis.
1542 * (If something broke then qemu will have to exit anyway since it's
1543 * got a bad migration state).
1545 migration_incoming_state_destroy();
1551 /* After this message we must be able to immediately receive postcopy data */
1552 static int loadvm_postcopy_handle_listen(MigrationIncomingState
*mis
)
1554 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_LISTENING
);
1555 trace_loadvm_postcopy_handle_listen();
1556 if (ps
!= POSTCOPY_INCOMING_ADVISE
&& ps
!= POSTCOPY_INCOMING_DISCARD
) {
1557 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps
);
1560 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
1562 * A rare case, we entered listen without having to do any discards,
1563 * so do the setup that's normally done at the time of the 1st discard.
1565 postcopy_ram_prepare_discard(mis
);
1569 * Sensitise RAM - can now generate requests for blocks that don't exist
1570 * However, at this point the CPU shouldn't be running, and the IO
1571 * shouldn't be doing anything yet so don't actually expect requests
1573 if (postcopy_ram_enable_notify(mis
)) {
1577 if (mis
->have_listen_thread
) {
1578 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
1582 mis
->have_listen_thread
= true;
1583 /* Start up the listening thread and wait for it to signal ready */
1584 qemu_sem_init(&mis
->listen_thread_sem
, 0);
1585 qemu_thread_create(&mis
->listen_thread
, "postcopy/listen",
1586 postcopy_ram_listen_thread
, mis
->from_src_file
,
1587 QEMU_THREAD_DETACHED
);
1588 qemu_sem_wait(&mis
->listen_thread_sem
);
1589 qemu_sem_destroy(&mis
->listen_thread_sem
);
1599 static void loadvm_postcopy_handle_run_bh(void *opaque
)
1601 Error
*local_err
= NULL
;
1602 HandleRunBhData
*data
= opaque
;
1604 /* TODO we should move all of this lot into postcopy_ram.c or a shared code
1607 cpu_synchronize_all_post_init();
1609 qemu_announce_self();
1611 /* Make sure all file formats flush their mutable metadata.
1612 * If we get an error here, just don't restart the VM yet. */
1613 bdrv_invalidate_cache_all(&local_err
);
1615 error_report_err(local_err
);
1620 trace_loadvm_postcopy_handle_run_cpu_sync();
1621 cpu_synchronize_all_post_init();
1623 trace_loadvm_postcopy_handle_run_vmstart();
1626 /* Hold onto your hats, starting the CPU */
1629 /* leave it paused and let management decide when to start the CPU */
1630 runstate_set(RUN_STATE_PAUSED
);
1633 qemu_bh_delete(data
->bh
);
1637 /* After all discards we can start running and asking for pages */
1638 static int loadvm_postcopy_handle_run(MigrationIncomingState
*mis
)
1640 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_RUNNING
);
1641 HandleRunBhData
*data
;
1643 trace_loadvm_postcopy_handle_run();
1644 if (ps
!= POSTCOPY_INCOMING_LISTENING
) {
1645 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps
);
1649 data
= g_new(HandleRunBhData
, 1);
1650 data
->bh
= qemu_bh_new(loadvm_postcopy_handle_run_bh
, data
);
1651 qemu_bh_schedule(data
->bh
);
1653 /* We need to finish reading the stream from the package
1654 * and also stop reading anything more from the stream that loaded the
1655 * package (since it's now being read by the listener thread).
1656 * LOADVM_QUIT will quit all the layers of nested loadvm loops.
1662 * Immediately following this command is a blob of data containing an embedded
1663 * chunk of migration stream; read it and load it.
1665 * @mis: Incoming state
1666 * @length: Length of packaged data to read
1668 * Returns: Negative values on error
1671 static int loadvm_handle_cmd_packaged(MigrationIncomingState
*mis
)
1675 QIOChannelBuffer
*bioc
;
1677 length
= qemu_get_be32(mis
->from_src_file
);
1678 trace_loadvm_handle_cmd_packaged(length
);
1680 if (length
> MAX_VM_CMD_PACKAGED_SIZE
) {
1681 error_report("Unreasonably large packaged state: %zu", length
);
1685 bioc
= qio_channel_buffer_new(length
);
1686 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-loadvm-buffer");
1687 ret
= qemu_get_buffer(mis
->from_src_file
,
1690 if (ret
!= length
) {
1691 object_unref(OBJECT(bioc
));
1692 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
1694 return (ret
< 0) ? ret
: -EAGAIN
;
1696 bioc
->usage
+= length
;
1697 trace_loadvm_handle_cmd_packaged_received(ret
);
1699 QEMUFile
*packf
= qemu_fopen_channel_input(QIO_CHANNEL(bioc
));
1701 ret
= qemu_loadvm_state_main(packf
, mis
);
1702 trace_loadvm_handle_cmd_packaged_main(ret
);
1704 object_unref(OBJECT(bioc
));
1710 * Process an incoming 'QEMU_VM_COMMAND'
1711 * 0 just a normal return
1712 * LOADVM_QUIT All good, but exit the loop
1715 static int loadvm_process_command(QEMUFile
*f
)
1717 MigrationIncomingState
*mis
= migration_incoming_get_current();
1722 cmd
= qemu_get_be16(f
);
1723 len
= qemu_get_be16(f
);
1725 trace_loadvm_process_command(cmd
, len
);
1726 if (cmd
>= MIG_CMD_MAX
|| cmd
== MIG_CMD_INVALID
) {
1727 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd
, len
);
1731 if (mig_cmd_args
[cmd
].len
!= -1 && mig_cmd_args
[cmd
].len
!= len
) {
1732 error_report("%s received with bad length - expecting %zu, got %d",
1733 mig_cmd_args
[cmd
].name
,
1734 (size_t)mig_cmd_args
[cmd
].len
, len
);
1739 case MIG_CMD_OPEN_RETURN_PATH
:
1740 if (mis
->to_src_file
) {
1741 error_report("CMD_OPEN_RETURN_PATH called when RP already open");
1742 /* Not really a problem, so don't give up */
1745 mis
->to_src_file
= qemu_file_get_return_path(f
);
1746 if (!mis
->to_src_file
) {
1747 error_report("CMD_OPEN_RETURN_PATH failed");
1753 tmp32
= qemu_get_be32(f
);
1754 trace_loadvm_process_command_ping(tmp32
);
1755 if (!mis
->to_src_file
) {
1756 error_report("CMD_PING (0x%x) received with no return path",
1760 migrate_send_rp_pong(mis
, tmp32
);
1763 case MIG_CMD_PACKAGED
:
1764 return loadvm_handle_cmd_packaged(mis
);
1766 case MIG_CMD_POSTCOPY_ADVISE
:
1767 return loadvm_postcopy_handle_advise(mis
);
1769 case MIG_CMD_POSTCOPY_LISTEN
:
1770 return loadvm_postcopy_handle_listen(mis
);
1772 case MIG_CMD_POSTCOPY_RUN
:
1773 return loadvm_postcopy_handle_run(mis
);
1775 case MIG_CMD_POSTCOPY_RAM_DISCARD
:
1776 return loadvm_postcopy_ram_handle_discard(mis
, len
);
1782 struct LoadStateEntry
{
1783 QLIST_ENTRY(LoadStateEntry
) entry
;
1790 * Read a footer off the wire and check that it matches the expected section
1792 * Returns: true if the footer was good
1793 * false if there is a problem (and calls error_report to say why)
1795 static bool check_section_footer(QEMUFile
*f
, LoadStateEntry
*le
)
1798 uint32_t read_section_id
;
1800 if (skip_section_footers
) {
1801 /* No footer to check */
1805 read_mark
= qemu_get_byte(f
);
1807 if (read_mark
!= QEMU_VM_SECTION_FOOTER
) {
1808 error_report("Missing section footer for %s", le
->se
->idstr
);
1812 read_section_id
= qemu_get_be32(f
);
1813 if (read_section_id
!= le
->section_id
) {
1814 error_report("Mismatched section id in footer for %s -"
1815 " read 0x%x expected 0x%x",
1816 le
->se
->idstr
, read_section_id
, le
->section_id
);
1824 void loadvm_free_handlers(MigrationIncomingState
*mis
)
1826 LoadStateEntry
*le
, *new_le
;
1828 QLIST_FOREACH_SAFE(le
, &mis
->loadvm_handlers
, entry
, new_le
) {
1829 QLIST_REMOVE(le
, entry
);
1835 qemu_loadvm_section_start_full(QEMUFile
*f
, MigrationIncomingState
*mis
)
1837 uint32_t instance_id
, version_id
, section_id
;
1843 /* Read section start */
1844 section_id
= qemu_get_be32(f
);
1845 if (!qemu_get_counted_string(f
, idstr
)) {
1846 error_report("Unable to read ID string for section %u",
1850 instance_id
= qemu_get_be32(f
);
1851 version_id
= qemu_get_be32(f
);
1853 trace_qemu_loadvm_state_section_startfull(section_id
, idstr
,
1854 instance_id
, version_id
);
1855 /* Find savevm section */
1856 se
= find_se(idstr
, instance_id
);
1858 error_report("Unknown savevm section or instance '%s' %d",
1859 idstr
, instance_id
);
1863 /* Validate version */
1864 if (version_id
> se
->version_id
) {
1865 error_report("savevm: unsupported version %d for '%s' v%d",
1866 version_id
, idstr
, se
->version_id
);
1870 /* Validate if it is a device's state */
1871 if (xen_enabled() && se
->is_ram
) {
1872 error_report("loadvm: %s RAM loading not allowed on Xen", idstr
);
1877 le
= g_malloc0(sizeof(*le
));
1880 le
->section_id
= section_id
;
1881 le
->version_id
= version_id
;
1882 QLIST_INSERT_HEAD(&mis
->loadvm_handlers
, le
, entry
);
1884 ret
= vmstate_load(f
, le
->se
, le
->version_id
);
1886 error_report("error while loading state for instance 0x%x of"
1887 " device '%s'", instance_id
, idstr
);
1890 if (!check_section_footer(f
, le
)) {
1898 qemu_loadvm_section_part_end(QEMUFile
*f
, MigrationIncomingState
*mis
)
1900 uint32_t section_id
;
1904 section_id
= qemu_get_be32(f
);
1906 trace_qemu_loadvm_state_section_partend(section_id
);
1907 QLIST_FOREACH(le
, &mis
->loadvm_handlers
, entry
) {
1908 if (le
->section_id
== section_id
) {
1913 error_report("Unknown savevm section %d", section_id
);
1917 ret
= vmstate_load(f
, le
->se
, le
->version_id
);
1919 error_report("error while loading state section id %d(%s)",
1920 section_id
, le
->se
->idstr
);
1923 if (!check_section_footer(f
, le
)) {
1930 static int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
)
1932 uint8_t section_type
;
1935 while ((section_type
= qemu_get_byte(f
)) != QEMU_VM_EOF
) {
1937 trace_qemu_loadvm_state_section(section_type
);
1938 switch (section_type
) {
1939 case QEMU_VM_SECTION_START
:
1940 case QEMU_VM_SECTION_FULL
:
1941 ret
= qemu_loadvm_section_start_full(f
, mis
);
1946 case QEMU_VM_SECTION_PART
:
1947 case QEMU_VM_SECTION_END
:
1948 ret
= qemu_loadvm_section_part_end(f
, mis
);
1953 case QEMU_VM_COMMAND
:
1954 ret
= loadvm_process_command(f
);
1955 trace_qemu_loadvm_state_section_command(ret
);
1956 if ((ret
< 0) || (ret
& LOADVM_QUIT
)) {
1961 error_report("Unknown savevm section type %d", section_type
);
1969 qemu_file_set_error(f
, ret
);
1974 int qemu_loadvm_state(QEMUFile
*f
)
1976 MigrationIncomingState
*mis
= migration_incoming_get_current();
1977 Error
*local_err
= NULL
;
1981 if (qemu_savevm_state_blocked(&local_err
)) {
1982 error_report_err(local_err
);
1986 v
= qemu_get_be32(f
);
1987 if (v
!= QEMU_VM_FILE_MAGIC
) {
1988 error_report("Not a migration stream");
1992 v
= qemu_get_be32(f
);
1993 if (v
== QEMU_VM_FILE_VERSION_COMPAT
) {
1994 error_report("SaveVM v2 format is obsolete and don't work anymore");
1997 if (v
!= QEMU_VM_FILE_VERSION
) {
1998 error_report("Unsupported migration stream version");
2002 if (!savevm_state
.skip_configuration
|| enforce_config_section()) {
2003 if (qemu_get_byte(f
) != QEMU_VM_CONFIGURATION
) {
2004 error_report("Configuration section missing");
2007 ret
= vmstate_load_state(f
, &vmstate_configuration
, &savevm_state
, 0);
2014 ret
= qemu_loadvm_state_main(f
, mis
);
2015 qemu_event_set(&mis
->main_thread_load_event
);
2017 trace_qemu_loadvm_state_post_main(ret
);
2019 if (mis
->have_listen_thread
) {
2020 /* Listen thread still going, can't clean up yet */
2025 ret
= qemu_file_get_error(f
);
2029 * Try to read in the VMDESC section as well, so that dumping tools that
2030 * intercept our migration stream have the chance to see it.
2033 /* We've got to be careful; if we don't read the data and just shut the fd
2034 * then the sender can error if we close while it's still sending.
2035 * We also mustn't read data that isn't there; some transports (RDMA)
2036 * will stall waiting for that data when the source has already closed.
2038 if (ret
== 0 && should_send_vmdesc()) {
2041 uint8_t section_type
= qemu_get_byte(f
);
2043 if (section_type
!= QEMU_VM_VMDESCRIPTION
) {
2044 error_report("Expected vmdescription section, but got %d",
2047 * It doesn't seem worth failing at this point since
2048 * we apparently have an otherwise valid VM state
2051 buf
= g_malloc(0x1000);
2052 size
= qemu_get_be32(f
);
2055 uint32_t read_chunk
= MIN(size
, 0x1000);
2056 qemu_get_buffer(f
, buf
, read_chunk
);
2063 cpu_synchronize_all_post_init();
2068 int save_vmstate(const char *name
, Error
**errp
)
2070 BlockDriverState
*bs
, *bs1
;
2071 QEMUSnapshotInfo sn1
, *sn
= &sn1
, old_sn1
, *old_sn
= &old_sn1
;
2074 int saved_vm_running
;
2075 uint64_t vm_state_size
;
2078 AioContext
*aio_context
;
2080 if (!bdrv_all_can_snapshot(&bs
)) {
2081 error_setg(errp
, "Device '%s' is writable but does not support "
2082 "snapshots", bdrv_get_device_name(bs
));
2086 /* Delete old snapshots of the same name */
2088 ret
= bdrv_all_delete_snapshot(name
, &bs1
, errp
);
2090 error_prepend(errp
, "Error while deleting snapshot on device "
2091 "'%s': ", bdrv_get_device_name(bs1
));
2096 bs
= bdrv_all_find_vmstate_bs();
2098 error_setg(errp
, "No block device can accept snapshots");
2101 aio_context
= bdrv_get_aio_context(bs
);
2103 saved_vm_running
= runstate_is_running();
2105 ret
= global_state_store();
2107 error_setg(errp
, "Error saving global state");
2110 vm_stop(RUN_STATE_SAVE_VM
);
2112 aio_context_acquire(aio_context
);
2114 memset(sn
, 0, sizeof(*sn
));
2116 /* fill auxiliary fields */
2117 qemu_gettimeofday(&tv
);
2118 sn
->date_sec
= tv
.tv_sec
;
2119 sn
->date_nsec
= tv
.tv_usec
* 1000;
2120 sn
->vm_clock_nsec
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
2123 ret
= bdrv_snapshot_find(bs
, old_sn
, name
);
2125 pstrcpy(sn
->name
, sizeof(sn
->name
), old_sn
->name
);
2126 pstrcpy(sn
->id_str
, sizeof(sn
->id_str
), old_sn
->id_str
);
2128 pstrcpy(sn
->name
, sizeof(sn
->name
), name
);
2131 /* cast below needed for OpenBSD where tv_sec is still 'long' */
2132 localtime_r((const time_t *)&tv
.tv_sec
, &tm
);
2133 strftime(sn
->name
, sizeof(sn
->name
), "vm-%Y%m%d%H%M%S", &tm
);
2136 /* save the VM state */
2137 f
= qemu_fopen_bdrv(bs
, 1);
2139 error_setg(errp
, "Could not open VM state file");
2142 ret
= qemu_savevm_state(f
, errp
);
2143 vm_state_size
= qemu_ftell(f
);
2149 ret
= bdrv_all_create_snapshot(sn
, bs
, vm_state_size
, &bs
);
2151 error_setg(errp
, "Error while creating snapshot on '%s'",
2152 bdrv_get_device_name(bs
));
2159 aio_context_release(aio_context
);
2160 if (saved_vm_running
) {
2166 void qmp_xen_save_devices_state(const char *filename
, Error
**errp
)
2169 QIOChannelFile
*ioc
;
2170 int saved_vm_running
;
2173 saved_vm_running
= runstate_is_running();
2174 vm_stop(RUN_STATE_SAVE_VM
);
2175 global_state_store_running();
2177 ioc
= qio_channel_file_new_path(filename
, O_WRONLY
| O_CREAT
, 0660, errp
);
2181 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-save-state");
2182 f
= qemu_fopen_channel_output(QIO_CHANNEL(ioc
));
2183 ret
= qemu_save_device_state(f
);
2186 error_setg(errp
, QERR_IO_ERROR
);
2190 if (saved_vm_running
) {
2195 void qmp_xen_load_devices_state(const char *filename
, Error
**errp
)
2198 QIOChannelFile
*ioc
;
2201 /* Guest must be paused before loading the device state; the RAM state
2202 * will already have been loaded by xc
2204 if (runstate_is_running()) {
2205 error_setg(errp
, "Cannot update device state while vm is running");
2208 vm_stop(RUN_STATE_RESTORE_VM
);
2210 ioc
= qio_channel_file_new_path(filename
, O_RDONLY
| O_BINARY
, 0, errp
);
2214 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-load-state");
2215 f
= qemu_fopen_channel_input(QIO_CHANNEL(ioc
));
2217 ret
= qemu_loadvm_state(f
);
2220 error_setg(errp
, QERR_IO_ERROR
);
2222 migration_incoming_state_destroy();
2225 int load_vmstate(const char *name
, Error
**errp
)
2227 BlockDriverState
*bs
, *bs_vm_state
;
2228 QEMUSnapshotInfo sn
;
2231 AioContext
*aio_context
;
2232 MigrationIncomingState
*mis
= migration_incoming_get_current();
2234 if (!bdrv_all_can_snapshot(&bs
)) {
2236 "Device '%s' is writable but does not support snapshots",
2237 bdrv_get_device_name(bs
));
2240 ret
= bdrv_all_find_snapshot(name
, &bs
);
2243 "Device '%s' does not have the requested snapshot '%s'",
2244 bdrv_get_device_name(bs
), name
);
2248 bs_vm_state
= bdrv_all_find_vmstate_bs();
2250 error_setg(errp
, "No block device supports snapshots");
2253 aio_context
= bdrv_get_aio_context(bs_vm_state
);
2255 /* Don't even try to load empty VM states */
2256 aio_context_acquire(aio_context
);
2257 ret
= bdrv_snapshot_find(bs_vm_state
, &sn
, name
);
2258 aio_context_release(aio_context
);
2261 } else if (sn
.vm_state_size
== 0) {
2262 error_setg(errp
, "This is a disk-only snapshot. Revert to it "
2263 " offline using qemu-img");
2267 /* Flush all IO requests so they don't interfere with the new state. */
2270 ret
= bdrv_all_goto_snapshot(name
, &bs
);
2272 error_setg(errp
, "Error %d while activating snapshot '%s' on '%s'",
2273 ret
, name
, bdrv_get_device_name(bs
));
2277 /* restore the VM state */
2278 f
= qemu_fopen_bdrv(bs_vm_state
, 0);
2280 error_setg(errp
, "Could not open VM state file");
2284 qemu_system_reset(VMRESET_SILENT
);
2285 mis
->from_src_file
= f
;
2287 aio_context_acquire(aio_context
);
2288 ret
= qemu_loadvm_state(f
);
2290 aio_context_release(aio_context
);
2292 migration_incoming_state_destroy();
2294 error_setg(errp
, "Error %d while loading VM state", ret
);
2301 void vmstate_register_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2303 qemu_ram_set_idstr(mr
->ram_block
,
2304 memory_region_name(mr
), dev
);
2307 void vmstate_unregister_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2309 qemu_ram_unset_idstr(mr
->ram_block
);
2312 void vmstate_register_ram_global(MemoryRegion
*mr
)
2314 vmstate_register_ram(mr
, NULL
);
2317 bool vmstate_check_only_migratable(const VMStateDescription
*vmsd
)
2319 /* check needed if --only-migratable is specified */
2320 if (!only_migratable
) {
2324 return !(vmsd
&& vmsd
->unmigratable
);