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 "migration/snapshot.h"
40 #include "qemu-file-channel.h"
41 #include "qemu-file.h"
43 #include "postcopy-ram.h"
44 #include "qapi/qmp/qerror.h"
45 #include "qemu/error-report.h"
46 #include "qemu/queue.h"
47 #include "sysemu/cpus.h"
48 #include "exec/memory.h"
49 #include "exec/target_page.h"
50 #include "qmp-commands.h"
52 #include "qemu/bitops.h"
54 #include "block/snapshot.h"
55 #include "qemu/cutils.h"
56 #include "io/channel-buffer.h"
57 #include "io/channel-file.h"
60 #define ETH_P_RARP 0x8035
62 #define ARP_HTYPE_ETH 0x0001
63 #define ARP_PTYPE_IP 0x0800
64 #define ARP_OP_REQUEST_REV 0x3
66 const unsigned int postcopy_ram_discard_version
= 0;
68 static bool skip_section_footers
;
70 /* Subcommands for QEMU_VM_COMMAND */
72 MIG_CMD_INVALID
= 0, /* Must be 0 */
73 MIG_CMD_OPEN_RETURN_PATH
, /* Tell the dest to open the Return path */
74 MIG_CMD_PING
, /* Request a PONG on the RP */
76 MIG_CMD_POSTCOPY_ADVISE
, /* Prior to any page transfers, just
77 warn we might want to do PC */
78 MIG_CMD_POSTCOPY_LISTEN
, /* Start listening for incoming
79 pages as it's running. */
80 MIG_CMD_POSTCOPY_RUN
, /* Start execution */
82 MIG_CMD_POSTCOPY_RAM_DISCARD
, /* A list of pages to discard that
83 were previously sent during
84 precopy but are dirty. */
85 MIG_CMD_PACKAGED
, /* Send a wrapped stream within this stream */
89 #define MAX_VM_CMD_PACKAGED_SIZE (1ul << 24)
90 static struct mig_cmd_args
{
91 ssize_t len
; /* -1 = variable */
94 [MIG_CMD_INVALID
] = { .len
= -1, .name
= "INVALID" },
95 [MIG_CMD_OPEN_RETURN_PATH
] = { .len
= 0, .name
= "OPEN_RETURN_PATH" },
96 [MIG_CMD_PING
] = { .len
= sizeof(uint32_t), .name
= "PING" },
97 [MIG_CMD_POSTCOPY_ADVISE
] = { .len
= 16, .name
= "POSTCOPY_ADVISE" },
98 [MIG_CMD_POSTCOPY_LISTEN
] = { .len
= 0, .name
= "POSTCOPY_LISTEN" },
99 [MIG_CMD_POSTCOPY_RUN
] = { .len
= 0, .name
= "POSTCOPY_RUN" },
100 [MIG_CMD_POSTCOPY_RAM_DISCARD
] = {
101 .len
= -1, .name
= "POSTCOPY_RAM_DISCARD" },
102 [MIG_CMD_PACKAGED
] = { .len
= 4, .name
= "PACKAGED" },
103 [MIG_CMD_MAX
] = { .len
= -1, .name
= "MAX" },
106 static int announce_self_create(uint8_t *buf
,
109 /* Ethernet header. */
110 memset(buf
, 0xff, 6); /* destination MAC addr */
111 memcpy(buf
+ 6, mac_addr
, 6); /* source MAC addr */
112 *(uint16_t *)(buf
+ 12) = htons(ETH_P_RARP
); /* ethertype */
115 *(uint16_t *)(buf
+ 14) = htons(ARP_HTYPE_ETH
); /* hardware addr space */
116 *(uint16_t *)(buf
+ 16) = htons(ARP_PTYPE_IP
); /* protocol addr space */
117 *(buf
+ 18) = 6; /* hardware addr length (ethernet) */
118 *(buf
+ 19) = 4; /* protocol addr length (IPv4) */
119 *(uint16_t *)(buf
+ 20) = htons(ARP_OP_REQUEST_REV
); /* opcode */
120 memcpy(buf
+ 22, mac_addr
, 6); /* source hw addr */
121 memset(buf
+ 28, 0x00, 4); /* source protocol addr */
122 memcpy(buf
+ 32, mac_addr
, 6); /* target hw addr */
123 memset(buf
+ 38, 0x00, 4); /* target protocol addr */
125 /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
126 memset(buf
+ 42, 0x00, 18);
128 return 60; /* len (FCS will be added by hardware) */
131 static void qemu_announce_self_iter(NICState
*nic
, void *opaque
)
136 trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic
->conf
->macaddr
));
137 len
= announce_self_create(buf
, nic
->conf
->macaddr
.a
);
139 qemu_send_packet_raw(qemu_get_queue(nic
), buf
, len
);
143 static void qemu_announce_self_once(void *opaque
)
145 static int count
= SELF_ANNOUNCE_ROUNDS
;
146 QEMUTimer
*timer
= *(QEMUTimer
**)opaque
;
148 qemu_foreach_nic(qemu_announce_self_iter
, NULL
);
151 /* delay 50ms, 150ms, 250ms, ... */
152 timer_mod(timer
, qemu_clock_get_ms(QEMU_CLOCK_REALTIME
) +
153 self_announce_delay(count
));
160 void qemu_announce_self(void)
162 static QEMUTimer
*timer
;
163 timer
= timer_new_ms(QEMU_CLOCK_REALTIME
, qemu_announce_self_once
, &timer
);
164 qemu_announce_self_once(&timer
);
167 /***********************************************************/
168 /* savevm/loadvm support */
170 static ssize_t
block_writev_buffer(void *opaque
, struct iovec
*iov
, int iovcnt
,
176 qemu_iovec_init_external(&qiov
, iov
, iovcnt
);
177 ret
= bdrv_writev_vmstate(opaque
, &qiov
, pos
);
185 static ssize_t
block_get_buffer(void *opaque
, uint8_t *buf
, int64_t pos
,
188 return bdrv_load_vmstate(opaque
, buf
, pos
, size
);
191 static int bdrv_fclose(void *opaque
)
193 return bdrv_flush(opaque
);
196 static const QEMUFileOps bdrv_read_ops
= {
197 .get_buffer
= block_get_buffer
,
201 static const QEMUFileOps bdrv_write_ops
= {
202 .writev_buffer
= block_writev_buffer
,
206 static QEMUFile
*qemu_fopen_bdrv(BlockDriverState
*bs
, int is_writable
)
209 return qemu_fopen_ops(bs
, &bdrv_write_ops
);
211 return qemu_fopen_ops(bs
, &bdrv_read_ops
);
215 /* QEMUFile timer support.
216 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
219 void timer_put(QEMUFile
*f
, QEMUTimer
*ts
)
221 uint64_t expire_time
;
223 expire_time
= timer_expire_time_ns(ts
);
224 qemu_put_be64(f
, expire_time
);
227 void timer_get(QEMUFile
*f
, QEMUTimer
*ts
)
229 uint64_t expire_time
;
231 expire_time
= qemu_get_be64(f
);
232 if (expire_time
!= -1) {
233 timer_mod_ns(ts
, expire_time
);
240 /* VMState timer support.
241 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
244 static int get_timer(QEMUFile
*f
, void *pv
, size_t size
, VMStateField
*field
)
251 static int put_timer(QEMUFile
*f
, void *pv
, size_t size
, VMStateField
*field
,
260 const VMStateInfo vmstate_info_timer
= {
267 typedef struct CompatEntry
{
272 typedef struct SaveStateEntry
{
273 QTAILQ_ENTRY(SaveStateEntry
) entry
;
278 /* version id read from the stream */
281 /* section id read from the stream */
284 const VMStateDescription
*vmsd
;
290 typedef struct SaveState
{
291 QTAILQ_HEAD(, SaveStateEntry
) handlers
;
292 int global_section_id
;
293 bool skip_configuration
;
296 uint32_t target_page_bits
;
299 static SaveState savevm_state
= {
300 .handlers
= QTAILQ_HEAD_INITIALIZER(savevm_state
.handlers
),
301 .global_section_id
= 0,
302 .skip_configuration
= false,
305 void savevm_skip_configuration(void)
307 savevm_state
.skip_configuration
= true;
311 static void configuration_pre_save(void *opaque
)
313 SaveState
*state
= opaque
;
314 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
316 state
->len
= strlen(current_name
);
317 state
->name
= current_name
;
318 state
->target_page_bits
= qemu_target_page_bits();
321 static int configuration_pre_load(void *opaque
)
323 SaveState
*state
= opaque
;
325 /* If there is no target-page-bits subsection it means the source
326 * predates the variable-target-page-bits support and is using the
327 * minimum possible value for this CPU.
329 state
->target_page_bits
= qemu_target_page_bits_min();
333 static int configuration_post_load(void *opaque
, int version_id
)
335 SaveState
*state
= opaque
;
336 const char *current_name
= MACHINE_GET_CLASS(current_machine
)->name
;
338 if (strncmp(state
->name
, current_name
, state
->len
) != 0) {
339 error_report("Machine type received is '%.*s' and local is '%s'",
340 (int) state
->len
, state
->name
, current_name
);
344 if (state
->target_page_bits
!= qemu_target_page_bits()) {
345 error_report("Received TARGET_PAGE_BITS is %d but local is %d",
346 state
->target_page_bits
, qemu_target_page_bits());
353 /* The target-page-bits subsection is present only if the
354 * target page size is not the same as the default (ie the
355 * minimum page size for a variable-page-size guest CPU).
356 * If it is present then it contains the actual target page
357 * bits for the machine, and migration will fail if the
358 * two ends don't agree about it.
360 static bool vmstate_target_page_bits_needed(void *opaque
)
362 return qemu_target_page_bits()
363 > qemu_target_page_bits_min();
366 static const VMStateDescription vmstate_target_page_bits
= {
367 .name
= "configuration/target-page-bits",
369 .minimum_version_id
= 1,
370 .needed
= vmstate_target_page_bits_needed
,
371 .fields
= (VMStateField
[]) {
372 VMSTATE_UINT32(target_page_bits
, SaveState
),
373 VMSTATE_END_OF_LIST()
377 static const VMStateDescription vmstate_configuration
= {
378 .name
= "configuration",
380 .pre_load
= configuration_pre_load
,
381 .post_load
= configuration_post_load
,
382 .pre_save
= configuration_pre_save
,
383 .fields
= (VMStateField
[]) {
384 VMSTATE_UINT32(len
, SaveState
),
385 VMSTATE_VBUFFER_ALLOC_UINT32(name
, SaveState
, 0, NULL
, len
),
386 VMSTATE_END_OF_LIST()
388 .subsections
= (const VMStateDescription
*[]) {
389 &vmstate_target_page_bits
,
394 static void dump_vmstate_vmsd(FILE *out_file
,
395 const VMStateDescription
*vmsd
, int indent
,
398 static void dump_vmstate_vmsf(FILE *out_file
, const VMStateField
*field
,
401 fprintf(out_file
, "%*s{\n", indent
, "");
403 fprintf(out_file
, "%*s\"field\": \"%s\",\n", indent
, "", field
->name
);
404 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
406 fprintf(out_file
, "%*s\"field_exists\": %s,\n", indent
, "",
407 field
->field_exists
? "true" : "false");
408 fprintf(out_file
, "%*s\"size\": %zu", indent
, "", field
->size
);
409 if (field
->vmsd
!= NULL
) {
410 fprintf(out_file
, ",\n");
411 dump_vmstate_vmsd(out_file
, field
->vmsd
, indent
, false);
413 fprintf(out_file
, "\n%*s}", indent
- 2, "");
416 static void dump_vmstate_vmss(FILE *out_file
,
417 const VMStateDescription
**subsection
,
420 if (*subsection
!= NULL
) {
421 dump_vmstate_vmsd(out_file
, *subsection
, indent
, true);
425 static void dump_vmstate_vmsd(FILE *out_file
,
426 const VMStateDescription
*vmsd
, int indent
,
430 fprintf(out_file
, "%*s{\n", indent
, "");
432 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", "Description");
435 fprintf(out_file
, "%*s\"name\": \"%s\",\n", indent
, "", vmsd
->name
);
436 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
438 fprintf(out_file
, "%*s\"minimum_version_id\": %d", indent
, "",
439 vmsd
->minimum_version_id
);
440 if (vmsd
->fields
!= NULL
) {
441 const VMStateField
*field
= vmsd
->fields
;
444 fprintf(out_file
, ",\n%*s\"Fields\": [\n", indent
, "");
446 while (field
->name
!= NULL
) {
447 if (field
->flags
& VMS_MUST_EXIST
) {
448 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
453 fprintf(out_file
, ",\n");
455 dump_vmstate_vmsf(out_file
, field
, indent
+ 2);
459 fprintf(out_file
, "\n%*s]", indent
, "");
461 if (vmsd
->subsections
!= NULL
) {
462 const VMStateDescription
**subsection
= vmsd
->subsections
;
465 fprintf(out_file
, ",\n%*s\"Subsections\": [\n", indent
, "");
467 while (*subsection
!= NULL
) {
469 fprintf(out_file
, ",\n");
471 dump_vmstate_vmss(out_file
, subsection
, indent
+ 2);
475 fprintf(out_file
, "\n%*s]", indent
, "");
477 fprintf(out_file
, "\n%*s}", indent
- 2, "");
480 static void dump_machine_type(FILE *out_file
)
484 mc
= MACHINE_GET_CLASS(current_machine
);
486 fprintf(out_file
, " \"vmschkmachine\": {\n");
487 fprintf(out_file
, " \"Name\": \"%s\"\n", mc
->name
);
488 fprintf(out_file
, " },\n");
491 void dump_vmstate_json_to_file(FILE *out_file
)
496 fprintf(out_file
, "{\n");
497 dump_machine_type(out_file
);
500 list
= object_class_get_list(TYPE_DEVICE
, true);
501 for (elt
= list
; elt
; elt
= elt
->next
) {
502 DeviceClass
*dc
= OBJECT_CLASS_CHECK(DeviceClass
, elt
->data
,
512 fprintf(out_file
, ",\n");
514 name
= object_class_get_name(OBJECT_CLASS(dc
));
515 fprintf(out_file
, "%*s\"%s\": {\n", indent
, "", name
);
517 fprintf(out_file
, "%*s\"Name\": \"%s\",\n", indent
, "", name
);
518 fprintf(out_file
, "%*s\"version_id\": %d,\n", indent
, "",
519 dc
->vmsd
->version_id
);
520 fprintf(out_file
, "%*s\"minimum_version_id\": %d,\n", indent
, "",
521 dc
->vmsd
->minimum_version_id
);
523 dump_vmstate_vmsd(out_file
, dc
->vmsd
, indent
, false);
525 fprintf(out_file
, "\n%*s}", indent
- 2, "");
528 fprintf(out_file
, "\n}\n");
532 static int calculate_new_instance_id(const char *idstr
)
537 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
538 if (strcmp(idstr
, se
->idstr
) == 0
539 && instance_id
<= se
->instance_id
) {
540 instance_id
= se
->instance_id
+ 1;
546 static int calculate_compat_instance_id(const char *idstr
)
551 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
556 if (strcmp(idstr
, se
->compat
->idstr
) == 0
557 && instance_id
<= se
->compat
->instance_id
) {
558 instance_id
= se
->compat
->instance_id
+ 1;
564 static inline MigrationPriority
save_state_priority(SaveStateEntry
*se
)
567 return se
->vmsd
->priority
;
569 return MIG_PRI_DEFAULT
;
572 static void savevm_state_handler_insert(SaveStateEntry
*nse
)
574 MigrationPriority priority
= save_state_priority(nse
);
577 assert(priority
<= MIG_PRI_MAX
);
579 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
580 if (save_state_priority(se
) < priority
) {
586 QTAILQ_INSERT_BEFORE(se
, nse
, entry
);
588 QTAILQ_INSERT_TAIL(&savevm_state
.handlers
, nse
, entry
);
592 /* TODO: Individual devices generally have very little idea about the rest
593 of the system, so instance_id should be removed/replaced.
594 Meanwhile pass -1 as instance_id if you do not already have a clearly
595 distinguishing id for all instances of your device class. */
596 int register_savevm_live(DeviceState
*dev
,
605 se
= g_new0(SaveStateEntry
, 1);
606 se
->version_id
= version_id
;
607 se
->section_id
= savevm_state
.global_section_id
++;
611 /* if this is a live_savem then set is_ram */
612 if (ops
->save_live_setup
!= NULL
) {
617 char *id
= qdev_get_dev_path(dev
);
619 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
621 error_report("Path too long for VMState (%s)", id
);
629 se
->compat
= g_new0(CompatEntry
, 1);
630 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), idstr
);
631 se
->compat
->instance_id
= instance_id
== -1 ?
632 calculate_compat_instance_id(idstr
) : instance_id
;
636 pstrcat(se
->idstr
, sizeof(se
->idstr
), idstr
);
638 if (instance_id
== -1) {
639 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
641 se
->instance_id
= instance_id
;
643 assert(!se
->compat
|| se
->instance_id
== 0);
644 savevm_state_handler_insert(se
);
648 int register_savevm(DeviceState
*dev
,
652 SaveStateHandler
*save_state
,
653 LoadStateHandler
*load_state
,
656 SaveVMHandlers
*ops
= g_new0(SaveVMHandlers
, 1);
657 ops
->save_state
= save_state
;
658 ops
->load_state
= load_state
;
659 return register_savevm_live(dev
, idstr
, instance_id
, version_id
,
663 void unregister_savevm(DeviceState
*dev
, const char *idstr
, void *opaque
)
665 SaveStateEntry
*se
, *new_se
;
669 char *path
= qdev_get_dev_path(dev
);
671 pstrcpy(id
, sizeof(id
), path
);
672 pstrcat(id
, sizeof(id
), "/");
676 pstrcat(id
, sizeof(id
), idstr
);
678 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
679 if (strcmp(se
->idstr
, id
) == 0 && se
->opaque
== opaque
) {
680 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
688 int vmstate_register_with_alias_id(DeviceState
*dev
, int instance_id
,
689 const VMStateDescription
*vmsd
,
690 void *opaque
, int alias_id
,
691 int required_for_version
,
696 /* If this triggers, alias support can be dropped for the vmsd. */
697 assert(alias_id
== -1 || required_for_version
>= vmsd
->minimum_version_id
);
699 se
= g_new0(SaveStateEntry
, 1);
700 se
->version_id
= vmsd
->version_id
;
701 se
->section_id
= savevm_state
.global_section_id
++;
704 se
->alias_id
= alias_id
;
707 char *id
= qdev_get_dev_path(dev
);
709 if (snprintf(se
->idstr
, sizeof(se
->idstr
), "%s/", id
) >=
711 error_setg(errp
, "Path too long for VMState (%s)", id
);
719 se
->compat
= g_new0(CompatEntry
, 1);
720 pstrcpy(se
->compat
->idstr
, sizeof(se
->compat
->idstr
), vmsd
->name
);
721 se
->compat
->instance_id
= instance_id
== -1 ?
722 calculate_compat_instance_id(vmsd
->name
) : instance_id
;
726 pstrcat(se
->idstr
, sizeof(se
->idstr
), vmsd
->name
);
728 if (instance_id
== -1) {
729 se
->instance_id
= calculate_new_instance_id(se
->idstr
);
731 se
->instance_id
= instance_id
;
733 assert(!se
->compat
|| se
->instance_id
== 0);
734 savevm_state_handler_insert(se
);
738 void vmstate_unregister(DeviceState
*dev
, const VMStateDescription
*vmsd
,
741 SaveStateEntry
*se
, *new_se
;
743 QTAILQ_FOREACH_SAFE(se
, &savevm_state
.handlers
, entry
, new_se
) {
744 if (se
->vmsd
== vmsd
&& se
->opaque
== opaque
) {
745 QTAILQ_REMOVE(&savevm_state
.handlers
, se
, entry
);
752 static int vmstate_load(QEMUFile
*f
, SaveStateEntry
*se
)
754 trace_vmstate_load(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
755 if (!se
->vmsd
) { /* Old style */
756 return se
->ops
->load_state(f
, se
->opaque
, se
->load_version_id
);
758 return vmstate_load_state(f
, se
->vmsd
, se
->opaque
, se
->load_version_id
);
761 static void vmstate_save_old_style(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
763 int64_t old_offset
, size
;
765 old_offset
= qemu_ftell_fast(f
);
766 se
->ops
->save_state(f
, se
->opaque
);
767 size
= qemu_ftell_fast(f
) - old_offset
;
770 json_prop_int(vmdesc
, "size", size
);
771 json_start_array(vmdesc
, "fields");
772 json_start_object(vmdesc
, NULL
);
773 json_prop_str(vmdesc
, "name", "data");
774 json_prop_int(vmdesc
, "size", size
);
775 json_prop_str(vmdesc
, "type", "buffer");
776 json_end_object(vmdesc
);
777 json_end_array(vmdesc
);
781 static void vmstate_save(QEMUFile
*f
, SaveStateEntry
*se
, QJSON
*vmdesc
)
783 trace_vmstate_save(se
->idstr
, se
->vmsd
? se
->vmsd
->name
: "(old)");
785 vmstate_save_old_style(f
, se
, vmdesc
);
788 vmstate_save_state(f
, se
->vmsd
, se
->opaque
, vmdesc
);
791 void savevm_skip_section_footers(void)
793 skip_section_footers
= true;
797 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
799 static void save_section_header(QEMUFile
*f
, SaveStateEntry
*se
,
800 uint8_t section_type
)
802 qemu_put_byte(f
, section_type
);
803 qemu_put_be32(f
, se
->section_id
);
805 if (section_type
== QEMU_VM_SECTION_FULL
||
806 section_type
== QEMU_VM_SECTION_START
) {
808 size_t len
= strlen(se
->idstr
);
809 qemu_put_byte(f
, len
);
810 qemu_put_buffer(f
, (uint8_t *)se
->idstr
, len
);
812 qemu_put_be32(f
, se
->instance_id
);
813 qemu_put_be32(f
, se
->version_id
);
818 * Write a footer onto device sections that catches cases misformatted device
821 static void save_section_footer(QEMUFile
*f
, SaveStateEntry
*se
)
823 if (!skip_section_footers
) {
824 qemu_put_byte(f
, QEMU_VM_SECTION_FOOTER
);
825 qemu_put_be32(f
, se
->section_id
);
830 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
831 * command and associated data.
833 * @f: File to send command on
834 * @command: Command type to send
835 * @len: Length of associated data
836 * @data: Data associated with command.
838 static void qemu_savevm_command_send(QEMUFile
*f
,
839 enum qemu_vm_cmd command
,
843 trace_savevm_command_send(command
, len
);
844 qemu_put_byte(f
, QEMU_VM_COMMAND
);
845 qemu_put_be16(f
, (uint16_t)command
);
846 qemu_put_be16(f
, len
);
847 qemu_put_buffer(f
, data
, len
);
851 void qemu_savevm_send_ping(QEMUFile
*f
, uint32_t value
)
855 trace_savevm_send_ping(value
);
856 buf
= cpu_to_be32(value
);
857 qemu_savevm_command_send(f
, MIG_CMD_PING
, sizeof(value
), (uint8_t *)&buf
);
860 void qemu_savevm_send_open_return_path(QEMUFile
*f
)
862 trace_savevm_send_open_return_path();
863 qemu_savevm_command_send(f
, MIG_CMD_OPEN_RETURN_PATH
, 0, NULL
);
866 /* We have a buffer of data to send; we don't want that all to be loaded
867 * by the command itself, so the command contains just the length of the
868 * extra buffer that we then send straight after it.
869 * TODO: Must be a better way to organise that
875 int qemu_savevm_send_packaged(QEMUFile
*f
, const uint8_t *buf
, size_t len
)
879 if (len
> MAX_VM_CMD_PACKAGED_SIZE
) {
880 error_report("%s: Unreasonably large packaged state: %zu",
885 tmp
= cpu_to_be32(len
);
887 trace_qemu_savevm_send_packaged();
888 qemu_savevm_command_send(f
, MIG_CMD_PACKAGED
, 4, (uint8_t *)&tmp
);
890 qemu_put_buffer(f
, buf
, len
);
895 /* Send prior to any postcopy transfer */
896 void qemu_savevm_send_postcopy_advise(QEMUFile
*f
)
899 tmp
[0] = cpu_to_be64(ram_pagesize_summary());
900 tmp
[1] = cpu_to_be64(qemu_target_page_size());
902 trace_qemu_savevm_send_postcopy_advise();
903 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_ADVISE
, 16, (uint8_t *)tmp
);
906 /* Sent prior to starting the destination running in postcopy, discard pages
907 * that have already been sent but redirtied on the source.
908 * CMD_POSTCOPY_RAM_DISCARD consist of:
910 * byte Length of name field (not including 0)
911 * n x byte RAM block name
912 * byte 0 terminator (just for safety)
913 * n x Byte ranges within the named RAMBlock
914 * be64 Start of the range
917 * name: RAMBlock name that these entries are part of
918 * len: Number of page entries
919 * start_list: 'len' addresses
920 * length_list: 'len' addresses
923 void qemu_savevm_send_postcopy_ram_discard(QEMUFile
*f
, const char *name
,
925 uint64_t *start_list
,
926 uint64_t *length_list
)
931 size_t name_len
= strlen(name
);
933 trace_qemu_savevm_send_postcopy_ram_discard(name
, len
);
934 assert(name_len
< 256);
935 buf
= g_malloc0(1 + 1 + name_len
+ 1 + (8 + 8) * len
);
936 buf
[0] = postcopy_ram_discard_version
;
938 memcpy(buf
+ 2, name
, name_len
);
939 tmplen
= 2 + name_len
;
940 buf
[tmplen
++] = '\0';
942 for (t
= 0; t
< len
; t
++) {
943 stq_be_p(buf
+ tmplen
, start_list
[t
]);
945 stq_be_p(buf
+ tmplen
, length_list
[t
]);
948 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RAM_DISCARD
, tmplen
, buf
);
952 /* Get the destination into a state where it can receive postcopy data. */
953 void qemu_savevm_send_postcopy_listen(QEMUFile
*f
)
955 trace_savevm_send_postcopy_listen();
956 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_LISTEN
, 0, NULL
);
959 /* Kick the destination into running */
960 void qemu_savevm_send_postcopy_run(QEMUFile
*f
)
962 trace_savevm_send_postcopy_run();
963 qemu_savevm_command_send(f
, MIG_CMD_POSTCOPY_RUN
, 0, NULL
);
966 bool qemu_savevm_state_blocked(Error
**errp
)
970 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
971 if (se
->vmsd
&& se
->vmsd
->unmigratable
) {
972 error_setg(errp
, "State blocked by non-migratable device '%s'",
980 static bool enforce_config_section(void)
982 MachineState
*machine
= MACHINE(qdev_get_machine());
983 return machine
->enforce_config_section
;
986 void qemu_savevm_state_header(QEMUFile
*f
)
988 trace_savevm_state_header();
989 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
990 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
992 if (!savevm_state
.skip_configuration
|| enforce_config_section()) {
993 qemu_put_byte(f
, QEMU_VM_CONFIGURATION
);
994 vmstate_save_state(f
, &vmstate_configuration
, &savevm_state
, 0);
999 void qemu_savevm_state_begin(QEMUFile
*f
)
1004 trace_savevm_state_begin();
1005 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1006 if (!se
->ops
|| !se
->ops
->save_live_setup
) {
1009 if (se
->ops
&& se
->ops
->is_active
) {
1010 if (!se
->ops
->is_active(se
->opaque
)) {
1014 save_section_header(f
, se
, QEMU_VM_SECTION_START
);
1016 ret
= se
->ops
->save_live_setup(f
, se
->opaque
);
1017 save_section_footer(f
, se
);
1019 qemu_file_set_error(f
, ret
);
1026 * this function has three return values:
1027 * negative: there was one error, and we have -errno.
1028 * 0 : We haven't finished, caller have to go again
1029 * 1 : We have finished, we can go to complete phase
1031 int qemu_savevm_state_iterate(QEMUFile
*f
, bool postcopy
)
1036 trace_savevm_state_iterate();
1037 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1038 if (!se
->ops
|| !se
->ops
->save_live_iterate
) {
1041 if (se
->ops
&& se
->ops
->is_active
) {
1042 if (!se
->ops
->is_active(se
->opaque
)) {
1047 * In the postcopy phase, any device that doesn't know how to
1048 * do postcopy should have saved it's state in the _complete
1049 * call that's already run, it might get confused if we call
1050 * iterate afterwards.
1052 if (postcopy
&& !se
->ops
->save_live_complete_postcopy
) {
1055 if (qemu_file_rate_limit(f
)) {
1058 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1060 save_section_header(f
, se
, QEMU_VM_SECTION_PART
);
1062 ret
= se
->ops
->save_live_iterate(f
, se
->opaque
);
1063 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1064 save_section_footer(f
, se
);
1067 qemu_file_set_error(f
, ret
);
1070 /* Do not proceed to the next vmstate before this one reported
1071 completion of the current stage. This serializes the migration
1072 and reduces the probability that a faster changing state is
1073 synchronized over and over again. */
1080 static bool should_send_vmdesc(void)
1082 MachineState
*machine
= MACHINE(qdev_get_machine());
1083 bool in_postcopy
= migration_in_postcopy();
1084 return !machine
->suppress_vmdesc
&& !in_postcopy
;
1088 * Calls the save_live_complete_postcopy methods
1089 * causing the last few pages to be sent immediately and doing any associated
1091 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
1092 * all the other devices, but that happens at the point we switch to postcopy.
1094 void qemu_savevm_state_complete_postcopy(QEMUFile
*f
)
1099 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1100 if (!se
->ops
|| !se
->ops
->save_live_complete_postcopy
) {
1103 if (se
->ops
&& se
->ops
->is_active
) {
1104 if (!se
->ops
->is_active(se
->opaque
)) {
1108 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1110 qemu_put_byte(f
, QEMU_VM_SECTION_END
);
1111 qemu_put_be32(f
, se
->section_id
);
1113 ret
= se
->ops
->save_live_complete_postcopy(f
, se
->opaque
);
1114 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1115 save_section_footer(f
, se
);
1117 qemu_file_set_error(f
, ret
);
1122 qemu_put_byte(f
, QEMU_VM_EOF
);
1126 void qemu_savevm_state_complete_precopy(QEMUFile
*f
, bool iterable_only
)
1132 bool in_postcopy
= migration_in_postcopy();
1134 trace_savevm_state_complete_precopy();
1136 cpu_synchronize_all_states();
1138 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1140 (in_postcopy
&& se
->ops
->save_live_complete_postcopy
) ||
1141 (in_postcopy
&& !iterable_only
) ||
1142 !se
->ops
->save_live_complete_precopy
) {
1146 if (se
->ops
&& se
->ops
->is_active
) {
1147 if (!se
->ops
->is_active(se
->opaque
)) {
1151 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1153 save_section_header(f
, se
, QEMU_VM_SECTION_END
);
1155 ret
= se
->ops
->save_live_complete_precopy(f
, se
->opaque
);
1156 trace_savevm_section_end(se
->idstr
, se
->section_id
, ret
);
1157 save_section_footer(f
, se
);
1159 qemu_file_set_error(f
, ret
);
1164 if (iterable_only
) {
1168 vmdesc
= qjson_new();
1169 json_prop_int(vmdesc
, "page_size", qemu_target_page_size());
1170 json_start_array(vmdesc
, "devices");
1171 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1173 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1176 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1177 trace_savevm_section_skip(se
->idstr
, se
->section_id
);
1181 trace_savevm_section_start(se
->idstr
, se
->section_id
);
1183 json_start_object(vmdesc
, NULL
);
1184 json_prop_str(vmdesc
, "name", se
->idstr
);
1185 json_prop_int(vmdesc
, "instance_id", se
->instance_id
);
1187 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1188 vmstate_save(f
, se
, vmdesc
);
1189 trace_savevm_section_end(se
->idstr
, se
->section_id
, 0);
1190 save_section_footer(f
, se
);
1192 json_end_object(vmdesc
);
1196 /* Postcopy stream will still be going */
1197 qemu_put_byte(f
, QEMU_VM_EOF
);
1200 json_end_array(vmdesc
);
1201 qjson_finish(vmdesc
);
1202 vmdesc_len
= strlen(qjson_get_str(vmdesc
));
1204 if (should_send_vmdesc()) {
1205 qemu_put_byte(f
, QEMU_VM_VMDESCRIPTION
);
1206 qemu_put_be32(f
, vmdesc_len
);
1207 qemu_put_buffer(f
, (uint8_t *)qjson_get_str(vmdesc
), vmdesc_len
);
1209 qjson_destroy(vmdesc
);
1214 /* Give an estimate of the amount left to be transferred,
1215 * the result is split into the amount for units that can and
1216 * for units that can't do postcopy.
1218 void qemu_savevm_state_pending(QEMUFile
*f
, uint64_t threshold_size
,
1219 uint64_t *res_non_postcopiable
,
1220 uint64_t *res_postcopiable
)
1224 *res_non_postcopiable
= 0;
1225 *res_postcopiable
= 0;
1228 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1229 if (!se
->ops
|| !se
->ops
->save_live_pending
) {
1232 if (se
->ops
&& se
->ops
->is_active
) {
1233 if (!se
->ops
->is_active(se
->opaque
)) {
1237 se
->ops
->save_live_pending(f
, se
->opaque
, threshold_size
,
1238 res_non_postcopiable
, res_postcopiable
);
1242 void qemu_savevm_state_cleanup(void)
1246 trace_savevm_state_cleanup();
1247 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1248 if (se
->ops
&& se
->ops
->cleanup
) {
1249 se
->ops
->cleanup(se
->opaque
);
1254 static int qemu_savevm_state(QEMUFile
*f
, Error
**errp
)
1257 MigrationState
*ms
= migrate_init();
1258 MigrationStatus status
;
1259 ms
->to_dst_file
= f
;
1261 if (migration_is_blocked(errp
)) {
1266 if (migrate_use_block()) {
1267 error_setg(errp
, "Block migration and snapshots are incompatible");
1272 qemu_mutex_unlock_iothread();
1273 qemu_savevm_state_header(f
);
1274 qemu_savevm_state_begin(f
);
1275 qemu_mutex_lock_iothread();
1277 while (qemu_file_get_error(f
) == 0) {
1278 if (qemu_savevm_state_iterate(f
, false) > 0) {
1283 ret
= qemu_file_get_error(f
);
1285 qemu_savevm_state_complete_precopy(f
, false);
1286 ret
= qemu_file_get_error(f
);
1288 qemu_savevm_state_cleanup();
1290 error_setg_errno(errp
, -ret
, "Error while writing VM state");
1295 status
= MIGRATION_STATUS_FAILED
;
1297 status
= MIGRATION_STATUS_COMPLETED
;
1299 migrate_set_state(&ms
->state
, MIGRATION_STATUS_SETUP
, status
);
1301 /* f is outer parameter, it should not stay in global migration state after
1302 * this function finished */
1303 ms
->to_dst_file
= NULL
;
1308 static int qemu_save_device_state(QEMUFile
*f
)
1312 qemu_put_be32(f
, QEMU_VM_FILE_MAGIC
);
1313 qemu_put_be32(f
, QEMU_VM_FILE_VERSION
);
1315 cpu_synchronize_all_states();
1317 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1321 if ((!se
->ops
|| !se
->ops
->save_state
) && !se
->vmsd
) {
1324 if (se
->vmsd
&& !vmstate_save_needed(se
->vmsd
, se
->opaque
)) {
1328 save_section_header(f
, se
, QEMU_VM_SECTION_FULL
);
1330 vmstate_save(f
, se
, NULL
);
1332 save_section_footer(f
, se
);
1335 qemu_put_byte(f
, QEMU_VM_EOF
);
1337 return qemu_file_get_error(f
);
1340 static SaveStateEntry
*find_se(const char *idstr
, int instance_id
)
1344 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1345 if (!strcmp(se
->idstr
, idstr
) &&
1346 (instance_id
== se
->instance_id
||
1347 instance_id
== se
->alias_id
))
1349 /* Migrating from an older version? */
1350 if (strstr(se
->idstr
, idstr
) && se
->compat
) {
1351 if (!strcmp(se
->compat
->idstr
, idstr
) &&
1352 (instance_id
== se
->compat
->instance_id
||
1353 instance_id
== se
->alias_id
))
1360 enum LoadVMExitCodes
{
1361 /* Allow a command to quit all layers of nested loadvm loops */
1365 static int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
);
1367 /* ------ incoming postcopy messages ------ */
1368 /* 'advise' arrives before any transfers just to tell us that a postcopy
1369 * *might* happen - it might be skipped if precopy transferred everything
1372 static int loadvm_postcopy_handle_advise(MigrationIncomingState
*mis
)
1374 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1375 uint64_t remote_pagesize_summary
, local_pagesize_summary
, remote_tps
;
1377 trace_loadvm_postcopy_handle_advise();
1378 if (ps
!= POSTCOPY_INCOMING_NONE
) {
1379 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps
);
1383 if (!postcopy_ram_supported_by_host()) {
1384 postcopy_state_set(POSTCOPY_INCOMING_NONE
);
1388 remote_pagesize_summary
= qemu_get_be64(mis
->from_src_file
);
1389 local_pagesize_summary
= ram_pagesize_summary();
1391 if (remote_pagesize_summary
!= local_pagesize_summary
) {
1393 * This detects two potential causes of mismatch:
1394 * a) A mismatch in host page sizes
1395 * Some combinations of mismatch are probably possible but it gets
1396 * a bit more complicated. In particular we need to place whole
1397 * host pages on the dest at once, and we need to ensure that we
1398 * handle dirtying to make sure we never end up sending part of
1399 * a hostpage on it's own.
1400 * b) The use of different huge page sizes on source/destination
1401 * a more fine grain test is performed during RAM block migration
1402 * but this test here causes a nice early clear failure, and
1403 * also fails when passed to an older qemu that doesn't
1406 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
1408 remote_pagesize_summary
, local_pagesize_summary
);
1412 remote_tps
= qemu_get_be64(mis
->from_src_file
);
1413 if (remote_tps
!= qemu_target_page_size()) {
1415 * Again, some differences could be dealt with, but for now keep it
1418 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
1419 (int)remote_tps
, qemu_target_page_size());
1423 if (ram_postcopy_incoming_init(mis
)) {
1427 postcopy_state_set(POSTCOPY_INCOMING_ADVISE
);
1432 /* After postcopy we will be told to throw some pages away since they're
1433 * dirty and will have to be demand fetched. Must happen before CPU is
1435 * There can be 0..many of these messages, each encoding multiple pages.
1437 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState
*mis
,
1442 PostcopyState ps
= postcopy_state_get();
1444 trace_loadvm_postcopy_ram_handle_discard();
1447 case POSTCOPY_INCOMING_ADVISE
:
1449 tmp
= postcopy_ram_prepare_discard(mis
);
1455 case POSTCOPY_INCOMING_DISCARD
:
1456 /* Expected state */
1460 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
1464 /* We're expecting a
1466 * a RAM ID string (length byte, name, 0 term)
1467 * then at least 1 16 byte chunk
1469 if (len
< (1 + 1 + 1 + 1 + 2 * 8)) {
1470 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1474 tmp
= qemu_get_byte(mis
->from_src_file
);
1475 if (tmp
!= postcopy_ram_discard_version
) {
1476 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp
);
1480 if (!qemu_get_counted_string(mis
->from_src_file
, ramid
)) {
1481 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
1484 tmp
= qemu_get_byte(mis
->from_src_file
);
1486 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp
);
1490 len
-= 3 + strlen(ramid
);
1492 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len
);
1495 trace_loadvm_postcopy_ram_handle_discard_header(ramid
, len
);
1497 uint64_t start_addr
, block_length
;
1498 start_addr
= qemu_get_be64(mis
->from_src_file
);
1499 block_length
= qemu_get_be64(mis
->from_src_file
);
1502 int ret
= ram_discard_range(ramid
, start_addr
, block_length
);
1507 trace_loadvm_postcopy_ram_handle_discard_end();
1513 * Triggered by a postcopy_listen command; this thread takes over reading
1514 * the input stream, leaving the main thread free to carry on loading the rest
1515 * of the device state (from RAM).
1516 * (TODO:This could do with being in a postcopy file - but there again it's
1517 * just another input loop, not that postcopy specific)
1519 static void *postcopy_ram_listen_thread(void *opaque
)
1521 QEMUFile
*f
= opaque
;
1522 MigrationIncomingState
*mis
= migration_incoming_get_current();
1525 migrate_set_state(&mis
->state
, MIGRATION_STATUS_ACTIVE
,
1526 MIGRATION_STATUS_POSTCOPY_ACTIVE
);
1527 qemu_sem_post(&mis
->listen_thread_sem
);
1528 trace_postcopy_ram_listen_thread_start();
1531 * Because we're a thread and not a coroutine we can't yield
1532 * in qemu_file, and thus we must be blocking now.
1534 qemu_file_set_blocking(f
, true);
1535 load_res
= qemu_loadvm_state_main(f
, mis
);
1536 /* And non-blocking again so we don't block in any cleanup */
1537 qemu_file_set_blocking(f
, false);
1539 trace_postcopy_ram_listen_thread_exit();
1541 error_report("%s: loadvm failed: %d", __func__
, load_res
);
1542 qemu_file_set_error(f
, load_res
);
1543 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1544 MIGRATION_STATUS_FAILED
);
1547 * This looks good, but it's possible that the device loading in the
1548 * main thread hasn't finished yet, and so we might not be in 'RUN'
1549 * state yet; wait for the end of the main thread.
1551 qemu_event_wait(&mis
->main_thread_load_event
);
1553 postcopy_ram_incoming_cleanup(mis
);
1557 * If something went wrong then we have a bad state so exit;
1558 * depending how far we got it might be possible at this point
1559 * to leave the guest running and fire MCEs for pages that never
1560 * arrived as a desperate recovery step.
1565 migrate_set_state(&mis
->state
, MIGRATION_STATUS_POSTCOPY_ACTIVE
,
1566 MIGRATION_STATUS_COMPLETED
);
1568 * If everything has worked fine, then the main thread has waited
1569 * for us to start, and we're the last use of the mis.
1570 * (If something broke then qemu will have to exit anyway since it's
1571 * got a bad migration state).
1573 migration_incoming_state_destroy();
1579 /* After this message we must be able to immediately receive postcopy data */
1580 static int loadvm_postcopy_handle_listen(MigrationIncomingState
*mis
)
1582 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_LISTENING
);
1583 trace_loadvm_postcopy_handle_listen();
1584 if (ps
!= POSTCOPY_INCOMING_ADVISE
&& ps
!= POSTCOPY_INCOMING_DISCARD
) {
1585 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps
);
1588 if (ps
== POSTCOPY_INCOMING_ADVISE
) {
1590 * A rare case, we entered listen without having to do any discards,
1591 * so do the setup that's normally done at the time of the 1st discard.
1593 postcopy_ram_prepare_discard(mis
);
1597 * Sensitise RAM - can now generate requests for blocks that don't exist
1598 * However, at this point the CPU shouldn't be running, and the IO
1599 * shouldn't be doing anything yet so don't actually expect requests
1601 if (postcopy_ram_enable_notify(mis
)) {
1605 if (mis
->have_listen_thread
) {
1606 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
1610 mis
->have_listen_thread
= true;
1611 /* Start up the listening thread and wait for it to signal ready */
1612 qemu_sem_init(&mis
->listen_thread_sem
, 0);
1613 qemu_thread_create(&mis
->listen_thread
, "postcopy/listen",
1614 postcopy_ram_listen_thread
, mis
->from_src_file
,
1615 QEMU_THREAD_DETACHED
);
1616 qemu_sem_wait(&mis
->listen_thread_sem
);
1617 qemu_sem_destroy(&mis
->listen_thread_sem
);
1627 static void loadvm_postcopy_handle_run_bh(void *opaque
)
1629 Error
*local_err
= NULL
;
1630 HandleRunBhData
*data
= opaque
;
1632 /* TODO we should move all of this lot into postcopy_ram.c or a shared code
1635 cpu_synchronize_all_post_init();
1637 qemu_announce_self();
1639 /* Make sure all file formats flush their mutable metadata.
1640 * If we get an error here, just don't restart the VM yet. */
1641 bdrv_invalidate_cache_all(&local_err
);
1643 error_report_err(local_err
);
1648 trace_loadvm_postcopy_handle_run_cpu_sync();
1649 cpu_synchronize_all_post_init();
1651 trace_loadvm_postcopy_handle_run_vmstart();
1654 /* Hold onto your hats, starting the CPU */
1657 /* leave it paused and let management decide when to start the CPU */
1658 runstate_set(RUN_STATE_PAUSED
);
1661 qemu_bh_delete(data
->bh
);
1665 /* After all discards we can start running and asking for pages */
1666 static int loadvm_postcopy_handle_run(MigrationIncomingState
*mis
)
1668 PostcopyState ps
= postcopy_state_set(POSTCOPY_INCOMING_RUNNING
);
1669 HandleRunBhData
*data
;
1671 trace_loadvm_postcopy_handle_run();
1672 if (ps
!= POSTCOPY_INCOMING_LISTENING
) {
1673 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps
);
1677 data
= g_new(HandleRunBhData
, 1);
1678 data
->bh
= qemu_bh_new(loadvm_postcopy_handle_run_bh
, data
);
1679 qemu_bh_schedule(data
->bh
);
1681 /* We need to finish reading the stream from the package
1682 * and also stop reading anything more from the stream that loaded the
1683 * package (since it's now being read by the listener thread).
1684 * LOADVM_QUIT will quit all the layers of nested loadvm loops.
1690 * Immediately following this command is a blob of data containing an embedded
1691 * chunk of migration stream; read it and load it.
1693 * @mis: Incoming state
1694 * @length: Length of packaged data to read
1696 * Returns: Negative values on error
1699 static int loadvm_handle_cmd_packaged(MigrationIncomingState
*mis
)
1703 QIOChannelBuffer
*bioc
;
1705 length
= qemu_get_be32(mis
->from_src_file
);
1706 trace_loadvm_handle_cmd_packaged(length
);
1708 if (length
> MAX_VM_CMD_PACKAGED_SIZE
) {
1709 error_report("Unreasonably large packaged state: %zu", length
);
1713 bioc
= qio_channel_buffer_new(length
);
1714 qio_channel_set_name(QIO_CHANNEL(bioc
), "migration-loadvm-buffer");
1715 ret
= qemu_get_buffer(mis
->from_src_file
,
1718 if (ret
!= length
) {
1719 object_unref(OBJECT(bioc
));
1720 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
1722 return (ret
< 0) ? ret
: -EAGAIN
;
1724 bioc
->usage
+= length
;
1725 trace_loadvm_handle_cmd_packaged_received(ret
);
1727 QEMUFile
*packf
= qemu_fopen_channel_input(QIO_CHANNEL(bioc
));
1729 ret
= qemu_loadvm_state_main(packf
, mis
);
1730 trace_loadvm_handle_cmd_packaged_main(ret
);
1732 object_unref(OBJECT(bioc
));
1738 * Process an incoming 'QEMU_VM_COMMAND'
1739 * 0 just a normal return
1740 * LOADVM_QUIT All good, but exit the loop
1743 static int loadvm_process_command(QEMUFile
*f
)
1745 MigrationIncomingState
*mis
= migration_incoming_get_current();
1750 cmd
= qemu_get_be16(f
);
1751 len
= qemu_get_be16(f
);
1753 trace_loadvm_process_command(cmd
, len
);
1754 if (cmd
>= MIG_CMD_MAX
|| cmd
== MIG_CMD_INVALID
) {
1755 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd
, len
);
1759 if (mig_cmd_args
[cmd
].len
!= -1 && mig_cmd_args
[cmd
].len
!= len
) {
1760 error_report("%s received with bad length - expecting %zu, got %d",
1761 mig_cmd_args
[cmd
].name
,
1762 (size_t)mig_cmd_args
[cmd
].len
, len
);
1767 case MIG_CMD_OPEN_RETURN_PATH
:
1768 if (mis
->to_src_file
) {
1769 error_report("CMD_OPEN_RETURN_PATH called when RP already open");
1770 /* Not really a problem, so don't give up */
1773 mis
->to_src_file
= qemu_file_get_return_path(f
);
1774 if (!mis
->to_src_file
) {
1775 error_report("CMD_OPEN_RETURN_PATH failed");
1781 tmp32
= qemu_get_be32(f
);
1782 trace_loadvm_process_command_ping(tmp32
);
1783 if (!mis
->to_src_file
) {
1784 error_report("CMD_PING (0x%x) received with no return path",
1788 migrate_send_rp_pong(mis
, tmp32
);
1791 case MIG_CMD_PACKAGED
:
1792 return loadvm_handle_cmd_packaged(mis
);
1794 case MIG_CMD_POSTCOPY_ADVISE
:
1795 return loadvm_postcopy_handle_advise(mis
);
1797 case MIG_CMD_POSTCOPY_LISTEN
:
1798 return loadvm_postcopy_handle_listen(mis
);
1800 case MIG_CMD_POSTCOPY_RUN
:
1801 return loadvm_postcopy_handle_run(mis
);
1803 case MIG_CMD_POSTCOPY_RAM_DISCARD
:
1804 return loadvm_postcopy_ram_handle_discard(mis
, len
);
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
, SaveStateEntry
*se
)
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", se
->idstr
);
1833 read_section_id
= qemu_get_be32(f
);
1834 if (read_section_id
!= se
->load_section_id
) {
1835 error_report("Mismatched section id in footer for %s -"
1836 " read 0x%x expected 0x%x",
1837 se
->idstr
, read_section_id
, se
->load_section_id
);
1846 qemu_loadvm_section_start_full(QEMUFile
*f
, MigrationIncomingState
*mis
)
1848 uint32_t instance_id
, version_id
, section_id
;
1853 /* Read section start */
1854 section_id
= qemu_get_be32(f
);
1855 if (!qemu_get_counted_string(f
, idstr
)) {
1856 error_report("Unable to read ID string for section %u",
1860 instance_id
= qemu_get_be32(f
);
1861 version_id
= qemu_get_be32(f
);
1863 trace_qemu_loadvm_state_section_startfull(section_id
, idstr
,
1864 instance_id
, version_id
);
1865 /* Find savevm section */
1866 se
= find_se(idstr
, instance_id
);
1868 error_report("Unknown savevm section or instance '%s' %d",
1869 idstr
, instance_id
);
1873 /* Validate version */
1874 if (version_id
> se
->version_id
) {
1875 error_report("savevm: unsupported version %d for '%s' v%d",
1876 version_id
, idstr
, se
->version_id
);
1879 se
->load_version_id
= version_id
;
1880 se
->load_section_id
= section_id
;
1882 /* Validate if it is a device's state */
1883 if (xen_enabled() && se
->is_ram
) {
1884 error_report("loadvm: %s RAM loading not allowed on Xen", idstr
);
1888 ret
= vmstate_load(f
, se
);
1890 error_report("error while loading state for instance 0x%x of"
1891 " device '%s'", instance_id
, idstr
);
1894 if (!check_section_footer(f
, se
)) {
1902 qemu_loadvm_section_part_end(QEMUFile
*f
, MigrationIncomingState
*mis
)
1904 uint32_t section_id
;
1908 section_id
= qemu_get_be32(f
);
1910 trace_qemu_loadvm_state_section_partend(section_id
);
1911 QTAILQ_FOREACH(se
, &savevm_state
.handlers
, entry
) {
1912 if (se
->load_section_id
== section_id
) {
1917 error_report("Unknown savevm section %d", section_id
);
1921 ret
= vmstate_load(f
, se
);
1923 error_report("error while loading state section id %d(%s)",
1924 section_id
, se
->idstr
);
1927 if (!check_section_footer(f
, se
)) {
1934 static int qemu_loadvm_state_main(QEMUFile
*f
, MigrationIncomingState
*mis
)
1936 uint8_t section_type
;
1939 while ((section_type
= qemu_get_byte(f
)) != QEMU_VM_EOF
) {
1941 trace_qemu_loadvm_state_section(section_type
);
1942 switch (section_type
) {
1943 case QEMU_VM_SECTION_START
:
1944 case QEMU_VM_SECTION_FULL
:
1945 ret
= qemu_loadvm_section_start_full(f
, mis
);
1950 case QEMU_VM_SECTION_PART
:
1951 case QEMU_VM_SECTION_END
:
1952 ret
= qemu_loadvm_section_part_end(f
, mis
);
1957 case QEMU_VM_COMMAND
:
1958 ret
= loadvm_process_command(f
);
1959 trace_qemu_loadvm_state_section_command(ret
);
1960 if ((ret
< 0) || (ret
& LOADVM_QUIT
)) {
1965 error_report("Unknown savevm section type %d", section_type
);
1973 qemu_file_set_error(f
, ret
);
1978 int qemu_loadvm_state(QEMUFile
*f
)
1980 MigrationIncomingState
*mis
= migration_incoming_get_current();
1981 Error
*local_err
= NULL
;
1985 if (qemu_savevm_state_blocked(&local_err
)) {
1986 error_report_err(local_err
);
1990 v
= qemu_get_be32(f
);
1991 if (v
!= QEMU_VM_FILE_MAGIC
) {
1992 error_report("Not a migration stream");
1996 v
= qemu_get_be32(f
);
1997 if (v
== QEMU_VM_FILE_VERSION_COMPAT
) {
1998 error_report("SaveVM v2 format is obsolete and don't work anymore");
2001 if (v
!= QEMU_VM_FILE_VERSION
) {
2002 error_report("Unsupported migration stream version");
2006 if (!savevm_state
.skip_configuration
|| enforce_config_section()) {
2007 if (qemu_get_byte(f
) != QEMU_VM_CONFIGURATION
) {
2008 error_report("Configuration section missing");
2011 ret
= vmstate_load_state(f
, &vmstate_configuration
, &savevm_state
, 0);
2018 ret
= qemu_loadvm_state_main(f
, mis
);
2019 qemu_event_set(&mis
->main_thread_load_event
);
2021 trace_qemu_loadvm_state_post_main(ret
);
2023 if (mis
->have_listen_thread
) {
2024 /* Listen thread still going, can't clean up yet */
2029 ret
= qemu_file_get_error(f
);
2033 * Try to read in the VMDESC section as well, so that dumping tools that
2034 * intercept our migration stream have the chance to see it.
2037 /* We've got to be careful; if we don't read the data and just shut the fd
2038 * then the sender can error if we close while it's still sending.
2039 * We also mustn't read data that isn't there; some transports (RDMA)
2040 * will stall waiting for that data when the source has already closed.
2042 if (ret
== 0 && should_send_vmdesc()) {
2045 uint8_t section_type
= qemu_get_byte(f
);
2047 if (section_type
!= QEMU_VM_VMDESCRIPTION
) {
2048 error_report("Expected vmdescription section, but got %d",
2051 * It doesn't seem worth failing at this point since
2052 * we apparently have an otherwise valid VM state
2055 buf
= g_malloc(0x1000);
2056 size
= qemu_get_be32(f
);
2059 uint32_t read_chunk
= MIN(size
, 0x1000);
2060 qemu_get_buffer(f
, buf
, read_chunk
);
2067 cpu_synchronize_all_post_init();
2072 int save_snapshot(const char *name
, Error
**errp
)
2074 BlockDriverState
*bs
, *bs1
;
2075 QEMUSnapshotInfo sn1
, *sn
= &sn1
, old_sn1
, *old_sn
= &old_sn1
;
2078 int saved_vm_running
;
2079 uint64_t vm_state_size
;
2082 AioContext
*aio_context
;
2084 if (!bdrv_all_can_snapshot(&bs
)) {
2085 error_setg(errp
, "Device '%s' is writable but does not support "
2086 "snapshots", bdrv_get_device_name(bs
));
2090 /* Delete old snapshots of the same name */
2092 ret
= bdrv_all_delete_snapshot(name
, &bs1
, errp
);
2094 error_prepend(errp
, "Error while deleting snapshot on device "
2095 "'%s': ", bdrv_get_device_name(bs1
));
2100 bs
= bdrv_all_find_vmstate_bs();
2102 error_setg(errp
, "No block device can accept snapshots");
2105 aio_context
= bdrv_get_aio_context(bs
);
2107 saved_vm_running
= runstate_is_running();
2109 ret
= global_state_store();
2111 error_setg(errp
, "Error saving global state");
2114 vm_stop(RUN_STATE_SAVE_VM
);
2116 aio_context_acquire(aio_context
);
2118 memset(sn
, 0, sizeof(*sn
));
2120 /* fill auxiliary fields */
2121 qemu_gettimeofday(&tv
);
2122 sn
->date_sec
= tv
.tv_sec
;
2123 sn
->date_nsec
= tv
.tv_usec
* 1000;
2124 sn
->vm_clock_nsec
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
2127 ret
= bdrv_snapshot_find(bs
, old_sn
, name
);
2129 pstrcpy(sn
->name
, sizeof(sn
->name
), old_sn
->name
);
2130 pstrcpy(sn
->id_str
, sizeof(sn
->id_str
), old_sn
->id_str
);
2132 pstrcpy(sn
->name
, sizeof(sn
->name
), name
);
2135 /* cast below needed for OpenBSD where tv_sec is still 'long' */
2136 localtime_r((const time_t *)&tv
.tv_sec
, &tm
);
2137 strftime(sn
->name
, sizeof(sn
->name
), "vm-%Y%m%d%H%M%S", &tm
);
2140 /* save the VM state */
2141 f
= qemu_fopen_bdrv(bs
, 1);
2143 error_setg(errp
, "Could not open VM state file");
2146 ret
= qemu_savevm_state(f
, errp
);
2147 vm_state_size
= qemu_ftell(f
);
2153 ret
= bdrv_all_create_snapshot(sn
, bs
, vm_state_size
, &bs
);
2155 error_setg(errp
, "Error while creating snapshot on '%s'",
2156 bdrv_get_device_name(bs
));
2163 aio_context_release(aio_context
);
2164 if (saved_vm_running
) {
2170 void qmp_xen_save_devices_state(const char *filename
, Error
**errp
)
2173 QIOChannelFile
*ioc
;
2174 int saved_vm_running
;
2177 saved_vm_running
= runstate_is_running();
2178 vm_stop(RUN_STATE_SAVE_VM
);
2179 global_state_store_running();
2181 ioc
= qio_channel_file_new_path(filename
, O_WRONLY
| O_CREAT
, 0660, errp
);
2185 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-save-state");
2186 f
= qemu_fopen_channel_output(QIO_CHANNEL(ioc
));
2187 ret
= qemu_save_device_state(f
);
2190 error_setg(errp
, QERR_IO_ERROR
);
2194 if (saved_vm_running
) {
2199 void qmp_xen_load_devices_state(const char *filename
, Error
**errp
)
2202 QIOChannelFile
*ioc
;
2205 /* Guest must be paused before loading the device state; the RAM state
2206 * will already have been loaded by xc
2208 if (runstate_is_running()) {
2209 error_setg(errp
, "Cannot update device state while vm is running");
2212 vm_stop(RUN_STATE_RESTORE_VM
);
2214 ioc
= qio_channel_file_new_path(filename
, O_RDONLY
| O_BINARY
, 0, errp
);
2218 qio_channel_set_name(QIO_CHANNEL(ioc
), "migration-xen-load-state");
2219 f
= qemu_fopen_channel_input(QIO_CHANNEL(ioc
));
2221 ret
= qemu_loadvm_state(f
);
2224 error_setg(errp
, QERR_IO_ERROR
);
2226 migration_incoming_state_destroy();
2229 int load_snapshot(const char *name
, Error
**errp
)
2231 BlockDriverState
*bs
, *bs_vm_state
;
2232 QEMUSnapshotInfo sn
;
2235 AioContext
*aio_context
;
2236 MigrationIncomingState
*mis
= migration_incoming_get_current();
2238 if (!bdrv_all_can_snapshot(&bs
)) {
2240 "Device '%s' is writable but does not support snapshots",
2241 bdrv_get_device_name(bs
));
2244 ret
= bdrv_all_find_snapshot(name
, &bs
);
2247 "Device '%s' does not have the requested snapshot '%s'",
2248 bdrv_get_device_name(bs
), name
);
2252 bs_vm_state
= bdrv_all_find_vmstate_bs();
2254 error_setg(errp
, "No block device supports snapshots");
2257 aio_context
= bdrv_get_aio_context(bs_vm_state
);
2259 /* Don't even try to load empty VM states */
2260 aio_context_acquire(aio_context
);
2261 ret
= bdrv_snapshot_find(bs_vm_state
, &sn
, name
);
2262 aio_context_release(aio_context
);
2265 } else if (sn
.vm_state_size
== 0) {
2266 error_setg(errp
, "This is a disk-only snapshot. Revert to it "
2267 " offline using qemu-img");
2271 /* Flush all IO requests so they don't interfere with the new state. */
2274 ret
= bdrv_all_goto_snapshot(name
, &bs
);
2276 error_setg(errp
, "Error %d while activating snapshot '%s' on '%s'",
2277 ret
, name
, bdrv_get_device_name(bs
));
2281 /* restore the VM state */
2282 f
= qemu_fopen_bdrv(bs_vm_state
, 0);
2284 error_setg(errp
, "Could not open VM state file");
2288 qemu_system_reset(SHUTDOWN_CAUSE_NONE
);
2289 mis
->from_src_file
= f
;
2291 aio_context_acquire(aio_context
);
2292 ret
= qemu_loadvm_state(f
);
2294 aio_context_release(aio_context
);
2296 migration_incoming_state_destroy();
2298 error_setg(errp
, "Error %d while loading VM state", ret
);
2305 void vmstate_register_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2307 qemu_ram_set_idstr(mr
->ram_block
,
2308 memory_region_name(mr
), dev
);
2311 void vmstate_unregister_ram(MemoryRegion
*mr
, DeviceState
*dev
)
2313 qemu_ram_unset_idstr(mr
->ram_block
);
2316 void vmstate_register_ram_global(MemoryRegion
*mr
)
2318 vmstate_register_ram(mr
, NULL
);
2321 bool vmstate_check_only_migratable(const VMStateDescription
*vmsd
)
2323 /* check needed if --only-migratable is specified */
2324 if (!only_migratable
) {
2328 return !(vmsd
&& vmsd
->unmigratable
);