vfio: simplify the conditional statements in vfio_msi_enable
[qemu/ar7.git] / migration / savevm.c
blobd9076897b8f0b06c84fe926c7936e27b864e2999
1 /*
2 * QEMU System Emulator
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009-2015 Red Hat Inc
7 * Authors:
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
26 * THE SOFTWARE.
29 #include "qemu/osdep.h"
30 #include "hw/boards.h"
31 #include "net/net.h"
32 #include "migration.h"
33 #include "migration/snapshot.h"
34 #include "migration/vmstate.h"
35 #include "migration/misc.h"
36 #include "migration/register.h"
37 #include "migration/global_state.h"
38 #include "ram.h"
39 #include "qemu-file-channel.h"
40 #include "qemu-file.h"
41 #include "savevm.h"
42 #include "postcopy-ram.h"
43 #include "qapi/error.h"
44 #include "qapi/qapi-commands-migration.h"
45 #include "qapi/qmp/json-writer.h"
46 #include "qapi/clone-visitor.h"
47 #include "qapi/qapi-builtin-visit.h"
48 #include "qapi/qmp/qerror.h"
49 #include "qemu/error-report.h"
50 #include "sysemu/cpus.h"
51 #include "exec/memory.h"
52 #include "exec/target_page.h"
53 #include "trace.h"
54 #include "qemu/iov.h"
55 #include "qemu/main-loop.h"
56 #include "block/snapshot.h"
57 #include "qemu/cutils.h"
58 #include "io/channel-buffer.h"
59 #include "io/channel-file.h"
60 #include "sysemu/replay.h"
61 #include "sysemu/runstate.h"
62 #include "sysemu/sysemu.h"
63 #include "sysemu/xen.h"
64 #include "migration/colo.h"
65 #include "qemu/bitmap.h"
66 #include "net/announce.h"
67 #include "qemu/yank.h"
68 #include "yank_functions.h"
70 const unsigned int postcopy_ram_discard_version;
72 /* Subcommands for QEMU_VM_COMMAND */
73 enum qemu_vm_cmd {
74 MIG_CMD_INVALID = 0, /* Must be 0 */
75 MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */
76 MIG_CMD_PING, /* Request a PONG on the RP */
78 MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just
79 warn we might want to do PC */
80 MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming
81 pages as it's running. */
82 MIG_CMD_POSTCOPY_RUN, /* Start execution */
84 MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
85 were previously sent during
86 precopy but are dirty. */
87 MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */
88 MIG_CMD_ENABLE_COLO, /* Enable COLO */
89 MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */
90 MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */
91 MIG_CMD_MAX
94 #define MAX_VM_CMD_PACKAGED_SIZE UINT32_MAX
95 static struct mig_cmd_args {
96 ssize_t len; /* -1 = variable */
97 const char *name;
98 } mig_cmd_args[] = {
99 [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" },
100 [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" },
101 [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" },
102 [MIG_CMD_POSTCOPY_ADVISE] = { .len = -1, .name = "POSTCOPY_ADVISE" },
103 [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" },
104 [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
105 [MIG_CMD_POSTCOPY_RAM_DISCARD] = {
106 .len = -1, .name = "POSTCOPY_RAM_DISCARD" },
107 [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" },
108 [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" },
109 [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
110 [MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
113 /* Note for MIG_CMD_POSTCOPY_ADVISE:
114 * The format of arguments is depending on postcopy mode:
115 * - postcopy RAM only
116 * uint64_t host page size
117 * uint64_t taget page size
119 * - postcopy RAM and postcopy dirty bitmaps
120 * format is the same as for postcopy RAM only
122 * - postcopy dirty bitmaps only
123 * Nothing. Command length field is 0.
125 * Be careful: adding a new postcopy entity with some other parameters should
126 * not break format self-description ability. Good way is to introduce some
127 * generic extendable format with an exception for two old entities.
130 /***********************************************************/
131 /* savevm/loadvm support */
133 static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
134 int64_t pos, Error **errp)
136 int ret;
137 QEMUIOVector qiov;
139 qemu_iovec_init_external(&qiov, iov, iovcnt);
140 ret = bdrv_writev_vmstate(opaque, &qiov, pos);
141 if (ret < 0) {
142 return ret;
145 return qiov.size;
148 static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
149 size_t size, Error **errp)
151 return bdrv_load_vmstate(opaque, buf, pos, size);
154 static int bdrv_fclose(void *opaque, Error **errp)
156 return bdrv_flush(opaque);
159 static const QEMUFileOps bdrv_read_ops = {
160 .get_buffer = block_get_buffer,
161 .close = bdrv_fclose
164 static const QEMUFileOps bdrv_write_ops = {
165 .writev_buffer = block_writev_buffer,
166 .close = bdrv_fclose
169 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
171 if (is_writable) {
172 return qemu_fopen_ops(bs, &bdrv_write_ops, false);
174 return qemu_fopen_ops(bs, &bdrv_read_ops, false);
178 /* QEMUFile timer support.
179 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
182 void timer_put(QEMUFile *f, QEMUTimer *ts)
184 uint64_t expire_time;
186 expire_time = timer_expire_time_ns(ts);
187 qemu_put_be64(f, expire_time);
190 void timer_get(QEMUFile *f, QEMUTimer *ts)
192 uint64_t expire_time;
194 expire_time = qemu_get_be64(f);
195 if (expire_time != -1) {
196 timer_mod_ns(ts, expire_time);
197 } else {
198 timer_del(ts);
203 /* VMState timer support.
204 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
207 static int get_timer(QEMUFile *f, void *pv, size_t size,
208 const VMStateField *field)
210 QEMUTimer *v = pv;
211 timer_get(f, v);
212 return 0;
215 static int put_timer(QEMUFile *f, void *pv, size_t size,
216 const VMStateField *field, JSONWriter *vmdesc)
218 QEMUTimer *v = pv;
219 timer_put(f, v);
221 return 0;
224 const VMStateInfo vmstate_info_timer = {
225 .name = "timer",
226 .get = get_timer,
227 .put = put_timer,
231 typedef struct CompatEntry {
232 char idstr[256];
233 int instance_id;
234 } CompatEntry;
236 typedef struct SaveStateEntry {
237 QTAILQ_ENTRY(SaveStateEntry) entry;
238 char idstr[256];
239 uint32_t instance_id;
240 int alias_id;
241 int version_id;
242 /* version id read from the stream */
243 int load_version_id;
244 int section_id;
245 /* section id read from the stream */
246 int load_section_id;
247 const SaveVMHandlers *ops;
248 const VMStateDescription *vmsd;
249 void *opaque;
250 CompatEntry *compat;
251 int is_ram;
252 } SaveStateEntry;
254 typedef struct SaveState {
255 QTAILQ_HEAD(, SaveStateEntry) handlers;
256 SaveStateEntry *handler_pri_head[MIG_PRI_MAX + 1];
257 int global_section_id;
258 uint32_t len;
259 const char *name;
260 uint32_t target_page_bits;
261 uint32_t caps_count;
262 MigrationCapability *capabilities;
263 QemuUUID uuid;
264 } SaveState;
266 static SaveState savevm_state = {
267 .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
268 .handler_pri_head = { [MIG_PRI_DEFAULT ... MIG_PRI_MAX] = NULL },
269 .global_section_id = 0,
272 static bool should_validate_capability(int capability)
274 assert(capability >= 0 && capability < MIGRATION_CAPABILITY__MAX);
275 /* Validate only new capabilities to keep compatibility. */
276 switch (capability) {
277 case MIGRATION_CAPABILITY_X_IGNORE_SHARED:
278 return true;
279 default:
280 return false;
284 static uint32_t get_validatable_capabilities_count(void)
286 MigrationState *s = migrate_get_current();
287 uint32_t result = 0;
288 int i;
289 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
290 if (should_validate_capability(i) && s->enabled_capabilities[i]) {
291 result++;
294 return result;
297 static int configuration_pre_save(void *opaque)
299 SaveState *state = opaque;
300 const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
301 MigrationState *s = migrate_get_current();
302 int i, j;
304 state->len = strlen(current_name);
305 state->name = current_name;
306 state->target_page_bits = qemu_target_page_bits();
308 state->caps_count = get_validatable_capabilities_count();
309 state->capabilities = g_renew(MigrationCapability, state->capabilities,
310 state->caps_count);
311 for (i = j = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
312 if (should_validate_capability(i) && s->enabled_capabilities[i]) {
313 state->capabilities[j++] = i;
316 state->uuid = qemu_uuid;
318 return 0;
321 static int configuration_post_save(void *opaque)
323 SaveState *state = opaque;
325 g_free(state->capabilities);
326 state->capabilities = NULL;
327 state->caps_count = 0;
328 return 0;
331 static int configuration_pre_load(void *opaque)
333 SaveState *state = opaque;
335 /* If there is no target-page-bits subsection it means the source
336 * predates the variable-target-page-bits support and is using the
337 * minimum possible value for this CPU.
339 state->target_page_bits = qemu_target_page_bits_min();
340 return 0;
343 static bool configuration_validate_capabilities(SaveState *state)
345 bool ret = true;
346 MigrationState *s = migrate_get_current();
347 unsigned long *source_caps_bm;
348 int i;
350 source_caps_bm = bitmap_new(MIGRATION_CAPABILITY__MAX);
351 for (i = 0; i < state->caps_count; i++) {
352 MigrationCapability capability = state->capabilities[i];
353 set_bit(capability, source_caps_bm);
356 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
357 bool source_state, target_state;
358 if (!should_validate_capability(i)) {
359 continue;
361 source_state = test_bit(i, source_caps_bm);
362 target_state = s->enabled_capabilities[i];
363 if (source_state != target_state) {
364 error_report("Capability %s is %s, but received capability is %s",
365 MigrationCapability_str(i),
366 target_state ? "on" : "off",
367 source_state ? "on" : "off");
368 ret = false;
369 /* Don't break here to report all failed capabilities */
373 g_free(source_caps_bm);
374 return ret;
377 static int configuration_post_load(void *opaque, int version_id)
379 SaveState *state = opaque;
380 const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
381 int ret = 0;
383 if (strncmp(state->name, current_name, state->len) != 0) {
384 error_report("Machine type received is '%.*s' and local is '%s'",
385 (int) state->len, state->name, current_name);
386 ret = -EINVAL;
387 goto out;
390 if (state->target_page_bits != qemu_target_page_bits()) {
391 error_report("Received TARGET_PAGE_BITS is %d but local is %d",
392 state->target_page_bits, qemu_target_page_bits());
393 ret = -EINVAL;
394 goto out;
397 if (!configuration_validate_capabilities(state)) {
398 ret = -EINVAL;
399 goto out;
402 out:
403 g_free((void *)state->name);
404 state->name = NULL;
405 state->len = 0;
406 g_free(state->capabilities);
407 state->capabilities = NULL;
408 state->caps_count = 0;
410 return ret;
413 static int get_capability(QEMUFile *f, void *pv, size_t size,
414 const VMStateField *field)
416 MigrationCapability *capability = pv;
417 char capability_str[UINT8_MAX + 1];
418 uint8_t len;
419 int i;
421 len = qemu_get_byte(f);
422 qemu_get_buffer(f, (uint8_t *)capability_str, len);
423 capability_str[len] = '\0';
424 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
425 if (!strcmp(MigrationCapability_str(i), capability_str)) {
426 *capability = i;
427 return 0;
430 error_report("Received unknown capability %s", capability_str);
431 return -EINVAL;
434 static int put_capability(QEMUFile *f, void *pv, size_t size,
435 const VMStateField *field, JSONWriter *vmdesc)
437 MigrationCapability *capability = pv;
438 const char *capability_str = MigrationCapability_str(*capability);
439 size_t len = strlen(capability_str);
440 assert(len <= UINT8_MAX);
442 qemu_put_byte(f, len);
443 qemu_put_buffer(f, (uint8_t *)capability_str, len);
444 return 0;
447 static const VMStateInfo vmstate_info_capability = {
448 .name = "capability",
449 .get = get_capability,
450 .put = put_capability,
453 /* The target-page-bits subsection is present only if the
454 * target page size is not the same as the default (ie the
455 * minimum page size for a variable-page-size guest CPU).
456 * If it is present then it contains the actual target page
457 * bits for the machine, and migration will fail if the
458 * two ends don't agree about it.
460 static bool vmstate_target_page_bits_needed(void *opaque)
462 return qemu_target_page_bits()
463 > qemu_target_page_bits_min();
466 static const VMStateDescription vmstate_target_page_bits = {
467 .name = "configuration/target-page-bits",
468 .version_id = 1,
469 .minimum_version_id = 1,
470 .needed = vmstate_target_page_bits_needed,
471 .fields = (VMStateField[]) {
472 VMSTATE_UINT32(target_page_bits, SaveState),
473 VMSTATE_END_OF_LIST()
477 static bool vmstate_capabilites_needed(void *opaque)
479 return get_validatable_capabilities_count() > 0;
482 static const VMStateDescription vmstate_capabilites = {
483 .name = "configuration/capabilities",
484 .version_id = 1,
485 .minimum_version_id = 1,
486 .needed = vmstate_capabilites_needed,
487 .fields = (VMStateField[]) {
488 VMSTATE_UINT32_V(caps_count, SaveState, 1),
489 VMSTATE_VARRAY_UINT32_ALLOC(capabilities, SaveState, caps_count, 1,
490 vmstate_info_capability,
491 MigrationCapability),
492 VMSTATE_END_OF_LIST()
496 static bool vmstate_uuid_needed(void *opaque)
498 return qemu_uuid_set && migrate_validate_uuid();
501 static int vmstate_uuid_post_load(void *opaque, int version_id)
503 SaveState *state = opaque;
504 char uuid_src[UUID_FMT_LEN + 1];
505 char uuid_dst[UUID_FMT_LEN + 1];
507 if (!qemu_uuid_set) {
509 * It's warning because user might not know UUID in some cases,
510 * e.g. load an old snapshot
512 qemu_uuid_unparse(&state->uuid, uuid_src);
513 warn_report("UUID is received %s, but local uuid isn't set",
514 uuid_src);
515 return 0;
517 if (!qemu_uuid_is_equal(&state->uuid, &qemu_uuid)) {
518 qemu_uuid_unparse(&state->uuid, uuid_src);
519 qemu_uuid_unparse(&qemu_uuid, uuid_dst);
520 error_report("UUID received is %s and local is %s", uuid_src, uuid_dst);
521 return -EINVAL;
523 return 0;
526 static const VMStateDescription vmstate_uuid = {
527 .name = "configuration/uuid",
528 .version_id = 1,
529 .minimum_version_id = 1,
530 .needed = vmstate_uuid_needed,
531 .post_load = vmstate_uuid_post_load,
532 .fields = (VMStateField[]) {
533 VMSTATE_UINT8_ARRAY_V(uuid.data, SaveState, sizeof(QemuUUID), 1),
534 VMSTATE_END_OF_LIST()
538 static const VMStateDescription vmstate_configuration = {
539 .name = "configuration",
540 .version_id = 1,
541 .pre_load = configuration_pre_load,
542 .post_load = configuration_post_load,
543 .pre_save = configuration_pre_save,
544 .post_save = configuration_post_save,
545 .fields = (VMStateField[]) {
546 VMSTATE_UINT32(len, SaveState),
547 VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len),
548 VMSTATE_END_OF_LIST()
550 .subsections = (const VMStateDescription *[]) {
551 &vmstate_target_page_bits,
552 &vmstate_capabilites,
553 &vmstate_uuid,
554 NULL
558 static void dump_vmstate_vmsd(FILE *out_file,
559 const VMStateDescription *vmsd, int indent,
560 bool is_subsection);
562 static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
563 int indent)
565 fprintf(out_file, "%*s{\n", indent, "");
566 indent += 2;
567 fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name);
568 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
569 field->version_id);
570 fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "",
571 field->field_exists ? "true" : "false");
572 fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size);
573 if (field->vmsd != NULL) {
574 fprintf(out_file, ",\n");
575 dump_vmstate_vmsd(out_file, field->vmsd, indent, false);
577 fprintf(out_file, "\n%*s}", indent - 2, "");
580 static void dump_vmstate_vmss(FILE *out_file,
581 const VMStateDescription **subsection,
582 int indent)
584 if (*subsection != NULL) {
585 dump_vmstate_vmsd(out_file, *subsection, indent, true);
589 static void dump_vmstate_vmsd(FILE *out_file,
590 const VMStateDescription *vmsd, int indent,
591 bool is_subsection)
593 if (is_subsection) {
594 fprintf(out_file, "%*s{\n", indent, "");
595 } else {
596 fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description");
598 indent += 2;
599 fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name);
600 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
601 vmsd->version_id);
602 fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "",
603 vmsd->minimum_version_id);
604 if (vmsd->fields != NULL) {
605 const VMStateField *field = vmsd->fields;
606 bool first;
608 fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, "");
609 first = true;
610 while (field->name != NULL) {
611 if (field->flags & VMS_MUST_EXIST) {
612 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
613 field++;
614 continue;
616 if (!first) {
617 fprintf(out_file, ",\n");
619 dump_vmstate_vmsf(out_file, field, indent + 2);
620 field++;
621 first = false;
623 fprintf(out_file, "\n%*s]", indent, "");
625 if (vmsd->subsections != NULL) {
626 const VMStateDescription **subsection = vmsd->subsections;
627 bool first;
629 fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
630 first = true;
631 while (*subsection != NULL) {
632 if (!first) {
633 fprintf(out_file, ",\n");
635 dump_vmstate_vmss(out_file, subsection, indent + 2);
636 subsection++;
637 first = false;
639 fprintf(out_file, "\n%*s]", indent, "");
641 fprintf(out_file, "\n%*s}", indent - 2, "");
644 static void dump_machine_type(FILE *out_file)
646 MachineClass *mc;
648 mc = MACHINE_GET_CLASS(current_machine);
650 fprintf(out_file, " \"vmschkmachine\": {\n");
651 fprintf(out_file, " \"Name\": \"%s\"\n", mc->name);
652 fprintf(out_file, " },\n");
655 void dump_vmstate_json_to_file(FILE *out_file)
657 GSList *list, *elt;
658 bool first;
660 fprintf(out_file, "{\n");
661 dump_machine_type(out_file);
663 first = true;
664 list = object_class_get_list(TYPE_DEVICE, true);
665 for (elt = list; elt; elt = elt->next) {
666 DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data,
667 TYPE_DEVICE);
668 const char *name;
669 int indent = 2;
671 if (!dc->vmsd) {
672 continue;
675 if (!first) {
676 fprintf(out_file, ",\n");
678 name = object_class_get_name(OBJECT_CLASS(dc));
679 fprintf(out_file, "%*s\"%s\": {\n", indent, "", name);
680 indent += 2;
681 fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name);
682 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
683 dc->vmsd->version_id);
684 fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "",
685 dc->vmsd->minimum_version_id);
687 dump_vmstate_vmsd(out_file, dc->vmsd, indent, false);
689 fprintf(out_file, "\n%*s}", indent - 2, "");
690 first = false;
692 fprintf(out_file, "\n}\n");
693 fclose(out_file);
694 g_slist_free(list);
697 static uint32_t calculate_new_instance_id(const char *idstr)
699 SaveStateEntry *se;
700 uint32_t instance_id = 0;
702 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
703 if (strcmp(idstr, se->idstr) == 0
704 && instance_id <= se->instance_id) {
705 instance_id = se->instance_id + 1;
708 /* Make sure we never loop over without being noticed */
709 assert(instance_id != VMSTATE_INSTANCE_ID_ANY);
710 return instance_id;
713 static int calculate_compat_instance_id(const char *idstr)
715 SaveStateEntry *se;
716 int instance_id = 0;
718 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
719 if (!se->compat) {
720 continue;
723 if (strcmp(idstr, se->compat->idstr) == 0
724 && instance_id <= se->compat->instance_id) {
725 instance_id = se->compat->instance_id + 1;
728 return instance_id;
731 static inline MigrationPriority save_state_priority(SaveStateEntry *se)
733 if (se->vmsd) {
734 return se->vmsd->priority;
736 return MIG_PRI_DEFAULT;
739 static void savevm_state_handler_insert(SaveStateEntry *nse)
741 MigrationPriority priority = save_state_priority(nse);
742 SaveStateEntry *se;
743 int i;
745 assert(priority <= MIG_PRI_MAX);
747 for (i = priority - 1; i >= 0; i--) {
748 se = savevm_state.handler_pri_head[i];
749 if (se != NULL) {
750 assert(save_state_priority(se) < priority);
751 break;
755 if (i >= 0) {
756 QTAILQ_INSERT_BEFORE(se, nse, entry);
757 } else {
758 QTAILQ_INSERT_TAIL(&savevm_state.handlers, nse, entry);
761 if (savevm_state.handler_pri_head[priority] == NULL) {
762 savevm_state.handler_pri_head[priority] = nse;
766 static void savevm_state_handler_remove(SaveStateEntry *se)
768 SaveStateEntry *next;
769 MigrationPriority priority = save_state_priority(se);
771 if (se == savevm_state.handler_pri_head[priority]) {
772 next = QTAILQ_NEXT(se, entry);
773 if (next != NULL && save_state_priority(next) == priority) {
774 savevm_state.handler_pri_head[priority] = next;
775 } else {
776 savevm_state.handler_pri_head[priority] = NULL;
779 QTAILQ_REMOVE(&savevm_state.handlers, se, entry);
782 /* TODO: Individual devices generally have very little idea about the rest
783 of the system, so instance_id should be removed/replaced.
784 Meanwhile pass -1 as instance_id if you do not already have a clearly
785 distinguishing id for all instances of your device class. */
786 int register_savevm_live(const char *idstr,
787 uint32_t instance_id,
788 int version_id,
789 const SaveVMHandlers *ops,
790 void *opaque)
792 SaveStateEntry *se;
794 se = g_new0(SaveStateEntry, 1);
795 se->version_id = version_id;
796 se->section_id = savevm_state.global_section_id++;
797 se->ops = ops;
798 se->opaque = opaque;
799 se->vmsd = NULL;
800 /* if this is a live_savem then set is_ram */
801 if (ops->save_setup != NULL) {
802 se->is_ram = 1;
805 pstrcat(se->idstr, sizeof(se->idstr), idstr);
807 if (instance_id == VMSTATE_INSTANCE_ID_ANY) {
808 se->instance_id = calculate_new_instance_id(se->idstr);
809 } else {
810 se->instance_id = instance_id;
812 assert(!se->compat || se->instance_id == 0);
813 savevm_state_handler_insert(se);
814 return 0;
817 void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque)
819 SaveStateEntry *se, *new_se;
820 char id[256] = "";
822 if (obj) {
823 char *oid = vmstate_if_get_id(obj);
824 if (oid) {
825 pstrcpy(id, sizeof(id), oid);
826 pstrcat(id, sizeof(id), "/");
827 g_free(oid);
830 pstrcat(id, sizeof(id), idstr);
832 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
833 if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
834 savevm_state_handler_remove(se);
835 g_free(se->compat);
836 g_free(se);
841 int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id,
842 const VMStateDescription *vmsd,
843 void *opaque, int alias_id,
844 int required_for_version,
845 Error **errp)
847 SaveStateEntry *se;
849 /* If this triggers, alias support can be dropped for the vmsd. */
850 assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id);
852 se = g_new0(SaveStateEntry, 1);
853 se->version_id = vmsd->version_id;
854 se->section_id = savevm_state.global_section_id++;
855 se->opaque = opaque;
856 se->vmsd = vmsd;
857 se->alias_id = alias_id;
859 if (obj) {
860 char *id = vmstate_if_get_id(obj);
861 if (id) {
862 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >=
863 sizeof(se->idstr)) {
864 error_setg(errp, "Path too long for VMState (%s)", id);
865 g_free(id);
866 g_free(se);
868 return -1;
870 g_free(id);
872 se->compat = g_new0(CompatEntry, 1);
873 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
874 se->compat->instance_id = instance_id == VMSTATE_INSTANCE_ID_ANY ?
875 calculate_compat_instance_id(vmsd->name) : instance_id;
876 instance_id = VMSTATE_INSTANCE_ID_ANY;
879 pstrcat(se->idstr, sizeof(se->idstr), vmsd->name);
881 if (instance_id == VMSTATE_INSTANCE_ID_ANY) {
882 se->instance_id = calculate_new_instance_id(se->idstr);
883 } else {
884 se->instance_id = instance_id;
886 assert(!se->compat || se->instance_id == 0);
887 savevm_state_handler_insert(se);
888 return 0;
891 void vmstate_unregister(VMStateIf *obj, const VMStateDescription *vmsd,
892 void *opaque)
894 SaveStateEntry *se, *new_se;
896 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
897 if (se->vmsd == vmsd && se->opaque == opaque) {
898 savevm_state_handler_remove(se);
899 g_free(se->compat);
900 g_free(se);
905 static int vmstate_load(QEMUFile *f, SaveStateEntry *se)
907 trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
908 if (!se->vmsd) { /* Old style */
909 return se->ops->load_state(f, se->opaque, se->load_version_id);
911 return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id);
914 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se,
915 JSONWriter *vmdesc)
917 int64_t old_offset, size;
919 old_offset = qemu_ftell_fast(f);
920 se->ops->save_state(f, se->opaque);
921 size = qemu_ftell_fast(f) - old_offset;
923 if (vmdesc) {
924 json_writer_int64(vmdesc, "size", size);
925 json_writer_start_array(vmdesc, "fields");
926 json_writer_start_object(vmdesc, NULL);
927 json_writer_str(vmdesc, "name", "data");
928 json_writer_int64(vmdesc, "size", size);
929 json_writer_str(vmdesc, "type", "buffer");
930 json_writer_end_object(vmdesc);
931 json_writer_end_array(vmdesc);
935 static int vmstate_save(QEMUFile *f, SaveStateEntry *se,
936 JSONWriter *vmdesc)
938 trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
939 if (!se->vmsd) {
940 vmstate_save_old_style(f, se, vmdesc);
941 return 0;
943 return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
947 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
949 static void save_section_header(QEMUFile *f, SaveStateEntry *se,
950 uint8_t section_type)
952 qemu_put_byte(f, section_type);
953 qemu_put_be32(f, se->section_id);
955 if (section_type == QEMU_VM_SECTION_FULL ||
956 section_type == QEMU_VM_SECTION_START) {
957 /* ID string */
958 size_t len = strlen(se->idstr);
959 qemu_put_byte(f, len);
960 qemu_put_buffer(f, (uint8_t *)se->idstr, len);
962 qemu_put_be32(f, se->instance_id);
963 qemu_put_be32(f, se->version_id);
968 * Write a footer onto device sections that catches cases misformatted device
969 * sections.
971 static void save_section_footer(QEMUFile *f, SaveStateEntry *se)
973 if (migrate_get_current()->send_section_footer) {
974 qemu_put_byte(f, QEMU_VM_SECTION_FOOTER);
975 qemu_put_be32(f, se->section_id);
980 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
981 * command and associated data.
983 * @f: File to send command on
984 * @command: Command type to send
985 * @len: Length of associated data
986 * @data: Data associated with command.
988 static void qemu_savevm_command_send(QEMUFile *f,
989 enum qemu_vm_cmd command,
990 uint16_t len,
991 uint8_t *data)
993 trace_savevm_command_send(command, len);
994 qemu_put_byte(f, QEMU_VM_COMMAND);
995 qemu_put_be16(f, (uint16_t)command);
996 qemu_put_be16(f, len);
997 qemu_put_buffer(f, data, len);
998 qemu_fflush(f);
1001 void qemu_savevm_send_colo_enable(QEMUFile *f)
1003 trace_savevm_send_colo_enable();
1004 qemu_savevm_command_send(f, MIG_CMD_ENABLE_COLO, 0, NULL);
1007 void qemu_savevm_send_ping(QEMUFile *f, uint32_t value)
1009 uint32_t buf;
1011 trace_savevm_send_ping(value);
1012 buf = cpu_to_be32(value);
1013 qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf);
1016 void qemu_savevm_send_open_return_path(QEMUFile *f)
1018 trace_savevm_send_open_return_path();
1019 qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
1022 /* We have a buffer of data to send; we don't want that all to be loaded
1023 * by the command itself, so the command contains just the length of the
1024 * extra buffer that we then send straight after it.
1025 * TODO: Must be a better way to organise that
1027 * Returns:
1028 * 0 on success
1029 * -ve on error
1031 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len)
1033 uint32_t tmp;
1035 if (len > MAX_VM_CMD_PACKAGED_SIZE) {
1036 error_report("%s: Unreasonably large packaged state: %zu",
1037 __func__, len);
1038 return -1;
1041 tmp = cpu_to_be32(len);
1043 trace_qemu_savevm_send_packaged();
1044 qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp);
1046 qemu_put_buffer(f, buf, len);
1048 return 0;
1051 /* Send prior to any postcopy transfer */
1052 void qemu_savevm_send_postcopy_advise(QEMUFile *f)
1054 if (migrate_postcopy_ram()) {
1055 uint64_t tmp[2];
1056 tmp[0] = cpu_to_be64(ram_pagesize_summary());
1057 tmp[1] = cpu_to_be64(qemu_target_page_size());
1059 trace_qemu_savevm_send_postcopy_advise();
1060 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE,
1061 16, (uint8_t *)tmp);
1062 } else {
1063 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 0, NULL);
1067 /* Sent prior to starting the destination running in postcopy, discard pages
1068 * that have already been sent but redirtied on the source.
1069 * CMD_POSTCOPY_RAM_DISCARD consist of:
1070 * byte version (0)
1071 * byte Length of name field (not including 0)
1072 * n x byte RAM block name
1073 * byte 0 terminator (just for safety)
1074 * n x Byte ranges within the named RAMBlock
1075 * be64 Start of the range
1076 * be64 Length
1078 * name: RAMBlock name that these entries are part of
1079 * len: Number of page entries
1080 * start_list: 'len' addresses
1081 * length_list: 'len' addresses
1084 void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
1085 uint16_t len,
1086 uint64_t *start_list,
1087 uint64_t *length_list)
1089 uint8_t *buf;
1090 uint16_t tmplen;
1091 uint16_t t;
1092 size_t name_len = strlen(name);
1094 trace_qemu_savevm_send_postcopy_ram_discard(name, len);
1095 assert(name_len < 256);
1096 buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len);
1097 buf[0] = postcopy_ram_discard_version;
1098 buf[1] = name_len;
1099 memcpy(buf + 2, name, name_len);
1100 tmplen = 2 + name_len;
1101 buf[tmplen++] = '\0';
1103 for (t = 0; t < len; t++) {
1104 stq_be_p(buf + tmplen, start_list[t]);
1105 tmplen += 8;
1106 stq_be_p(buf + tmplen, length_list[t]);
1107 tmplen += 8;
1109 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf);
1110 g_free(buf);
1113 /* Get the destination into a state where it can receive postcopy data. */
1114 void qemu_savevm_send_postcopy_listen(QEMUFile *f)
1116 trace_savevm_send_postcopy_listen();
1117 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL);
1120 /* Kick the destination into running */
1121 void qemu_savevm_send_postcopy_run(QEMUFile *f)
1123 trace_savevm_send_postcopy_run();
1124 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
1127 void qemu_savevm_send_postcopy_resume(QEMUFile *f)
1129 trace_savevm_send_postcopy_resume();
1130 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL);
1133 void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name)
1135 size_t len;
1136 char buf[256];
1138 trace_savevm_send_recv_bitmap(block_name);
1140 buf[0] = len = strlen(block_name);
1141 memcpy(buf + 1, block_name, len);
1143 qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf);
1146 bool qemu_savevm_state_blocked(Error **errp)
1148 SaveStateEntry *se;
1150 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1151 if (se->vmsd && se->vmsd->unmigratable) {
1152 error_setg(errp, "State blocked by non-migratable device '%s'",
1153 se->idstr);
1154 return true;
1157 return false;
1160 void qemu_savevm_non_migratable_list(strList **reasons)
1162 SaveStateEntry *se;
1164 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1165 if (se->vmsd && se->vmsd->unmigratable) {
1166 QAPI_LIST_PREPEND(*reasons,
1167 g_strdup_printf("non-migratable device: %s",
1168 se->idstr));
1173 void qemu_savevm_state_header(QEMUFile *f)
1175 trace_savevm_state_header();
1176 qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
1177 qemu_put_be32(f, QEMU_VM_FILE_VERSION);
1179 if (migrate_get_current()->send_configuration) {
1180 qemu_put_byte(f, QEMU_VM_CONFIGURATION);
1181 vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
1185 bool qemu_savevm_state_guest_unplug_pending(void)
1187 SaveStateEntry *se;
1189 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1190 if (se->vmsd && se->vmsd->dev_unplug_pending &&
1191 se->vmsd->dev_unplug_pending(se->opaque)) {
1192 return true;
1196 return false;
1199 void qemu_savevm_state_setup(QEMUFile *f)
1201 SaveStateEntry *se;
1202 Error *local_err = NULL;
1203 int ret;
1205 trace_savevm_state_setup();
1206 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1207 if (!se->ops || !se->ops->save_setup) {
1208 continue;
1210 if (se->ops->is_active) {
1211 if (!se->ops->is_active(se->opaque)) {
1212 continue;
1215 save_section_header(f, se, QEMU_VM_SECTION_START);
1217 ret = se->ops->save_setup(f, se->opaque);
1218 save_section_footer(f, se);
1219 if (ret < 0) {
1220 qemu_file_set_error(f, ret);
1221 break;
1225 if (precopy_notify(PRECOPY_NOTIFY_SETUP, &local_err)) {
1226 error_report_err(local_err);
1230 int qemu_savevm_state_resume_prepare(MigrationState *s)
1232 SaveStateEntry *se;
1233 int ret;
1235 trace_savevm_state_resume_prepare();
1237 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1238 if (!se->ops || !se->ops->resume_prepare) {
1239 continue;
1241 if (se->ops->is_active) {
1242 if (!se->ops->is_active(se->opaque)) {
1243 continue;
1246 ret = se->ops->resume_prepare(s, se->opaque);
1247 if (ret < 0) {
1248 return ret;
1252 return 0;
1256 * this function has three return values:
1257 * negative: there was one error, and we have -errno.
1258 * 0 : We haven't finished, caller have to go again
1259 * 1 : We have finished, we can go to complete phase
1261 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
1263 SaveStateEntry *se;
1264 int ret = 1;
1266 trace_savevm_state_iterate();
1267 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1268 if (!se->ops || !se->ops->save_live_iterate) {
1269 continue;
1271 if (se->ops->is_active &&
1272 !se->ops->is_active(se->opaque)) {
1273 continue;
1275 if (se->ops->is_active_iterate &&
1276 !se->ops->is_active_iterate(se->opaque)) {
1277 continue;
1280 * In the postcopy phase, any device that doesn't know how to
1281 * do postcopy should have saved it's state in the _complete
1282 * call that's already run, it might get confused if we call
1283 * iterate afterwards.
1285 if (postcopy &&
1286 !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) {
1287 continue;
1289 if (qemu_file_rate_limit(f)) {
1290 return 0;
1292 trace_savevm_section_start(se->idstr, se->section_id);
1294 save_section_header(f, se, QEMU_VM_SECTION_PART);
1296 ret = se->ops->save_live_iterate(f, se->opaque);
1297 trace_savevm_section_end(se->idstr, se->section_id, ret);
1298 save_section_footer(f, se);
1300 if (ret < 0) {
1301 error_report("failed to save SaveStateEntry with id(name): "
1302 "%d(%s): %d",
1303 se->section_id, se->idstr, ret);
1304 qemu_file_set_error(f, ret);
1306 if (ret <= 0) {
1307 /* Do not proceed to the next vmstate before this one reported
1308 completion of the current stage. This serializes the migration
1309 and reduces the probability that a faster changing state is
1310 synchronized over and over again. */
1311 break;
1314 return ret;
1317 static bool should_send_vmdesc(void)
1319 MachineState *machine = MACHINE(qdev_get_machine());
1320 bool in_postcopy = migration_in_postcopy();
1321 return !machine->suppress_vmdesc && !in_postcopy;
1325 * Calls the save_live_complete_postcopy methods
1326 * causing the last few pages to be sent immediately and doing any associated
1327 * cleanup.
1328 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
1329 * all the other devices, but that happens at the point we switch to postcopy.
1331 void qemu_savevm_state_complete_postcopy(QEMUFile *f)
1333 SaveStateEntry *se;
1334 int ret;
1336 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1337 if (!se->ops || !se->ops->save_live_complete_postcopy) {
1338 continue;
1340 if (se->ops->is_active) {
1341 if (!se->ops->is_active(se->opaque)) {
1342 continue;
1345 trace_savevm_section_start(se->idstr, se->section_id);
1346 /* Section type */
1347 qemu_put_byte(f, QEMU_VM_SECTION_END);
1348 qemu_put_be32(f, se->section_id);
1350 ret = se->ops->save_live_complete_postcopy(f, se->opaque);
1351 trace_savevm_section_end(se->idstr, se->section_id, ret);
1352 save_section_footer(f, se);
1353 if (ret < 0) {
1354 qemu_file_set_error(f, ret);
1355 return;
1359 qemu_put_byte(f, QEMU_VM_EOF);
1360 qemu_fflush(f);
1363 static
1364 int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy)
1366 SaveStateEntry *se;
1367 int ret;
1369 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1370 if (!se->ops ||
1371 (in_postcopy && se->ops->has_postcopy &&
1372 se->ops->has_postcopy(se->opaque)) ||
1373 !se->ops->save_live_complete_precopy) {
1374 continue;
1377 if (se->ops->is_active) {
1378 if (!se->ops->is_active(se->opaque)) {
1379 continue;
1382 trace_savevm_section_start(se->idstr, se->section_id);
1384 save_section_header(f, se, QEMU_VM_SECTION_END);
1386 ret = se->ops->save_live_complete_precopy(f, se->opaque);
1387 trace_savevm_section_end(se->idstr, se->section_id, ret);
1388 save_section_footer(f, se);
1389 if (ret < 0) {
1390 qemu_file_set_error(f, ret);
1391 return -1;
1395 return 0;
1398 int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
1399 bool in_postcopy,
1400 bool inactivate_disks)
1402 g_autoptr(JSONWriter) vmdesc = NULL;
1403 int vmdesc_len;
1404 SaveStateEntry *se;
1405 int ret;
1407 vmdesc = json_writer_new(false);
1408 json_writer_start_object(vmdesc, NULL);
1409 json_writer_int64(vmdesc, "page_size", qemu_target_page_size());
1410 json_writer_start_array(vmdesc, "devices");
1411 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1413 if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
1414 continue;
1416 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
1417 trace_savevm_section_skip(se->idstr, se->section_id);
1418 continue;
1421 trace_savevm_section_start(se->idstr, se->section_id);
1423 json_writer_start_object(vmdesc, NULL);
1424 json_writer_str(vmdesc, "name", se->idstr);
1425 json_writer_int64(vmdesc, "instance_id", se->instance_id);
1427 save_section_header(f, se, QEMU_VM_SECTION_FULL);
1428 ret = vmstate_save(f, se, vmdesc);
1429 if (ret) {
1430 qemu_file_set_error(f, ret);
1431 return ret;
1433 trace_savevm_section_end(se->idstr, se->section_id, 0);
1434 save_section_footer(f, se);
1436 json_writer_end_object(vmdesc);
1439 if (inactivate_disks) {
1440 /* Inactivate before sending QEMU_VM_EOF so that the
1441 * bdrv_activate_all() on the other end won't fail. */
1442 ret = bdrv_inactivate_all();
1443 if (ret) {
1444 error_report("%s: bdrv_inactivate_all() failed (%d)",
1445 __func__, ret);
1446 qemu_file_set_error(f, ret);
1447 return ret;
1450 if (!in_postcopy) {
1451 /* Postcopy stream will still be going */
1452 qemu_put_byte(f, QEMU_VM_EOF);
1455 json_writer_end_array(vmdesc);
1456 json_writer_end_object(vmdesc);
1457 vmdesc_len = strlen(json_writer_get(vmdesc));
1459 if (should_send_vmdesc()) {
1460 qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
1461 qemu_put_be32(f, vmdesc_len);
1462 qemu_put_buffer(f, (uint8_t *)json_writer_get(vmdesc), vmdesc_len);
1465 return 0;
1468 int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only,
1469 bool inactivate_disks)
1471 int ret;
1472 Error *local_err = NULL;
1473 bool in_postcopy = migration_in_postcopy();
1475 if (precopy_notify(PRECOPY_NOTIFY_COMPLETE, &local_err)) {
1476 error_report_err(local_err);
1479 trace_savevm_state_complete_precopy();
1481 cpu_synchronize_all_states();
1483 if (!in_postcopy || iterable_only) {
1484 ret = qemu_savevm_state_complete_precopy_iterable(f, in_postcopy);
1485 if (ret) {
1486 return ret;
1490 if (iterable_only) {
1491 goto flush;
1494 ret = qemu_savevm_state_complete_precopy_non_iterable(f, in_postcopy,
1495 inactivate_disks);
1496 if (ret) {
1497 return ret;
1500 flush:
1501 qemu_fflush(f);
1502 return 0;
1505 /* Give an estimate of the amount left to be transferred,
1506 * the result is split into the amount for units that can and
1507 * for units that can't do postcopy.
1509 void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size,
1510 uint64_t *res_precopy_only,
1511 uint64_t *res_compatible,
1512 uint64_t *res_postcopy_only)
1514 SaveStateEntry *se;
1516 *res_precopy_only = 0;
1517 *res_compatible = 0;
1518 *res_postcopy_only = 0;
1521 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1522 if (!se->ops || !se->ops->save_live_pending) {
1523 continue;
1525 if (se->ops->is_active) {
1526 if (!se->ops->is_active(se->opaque)) {
1527 continue;
1530 se->ops->save_live_pending(f, se->opaque, threshold_size,
1531 res_precopy_only, res_compatible,
1532 res_postcopy_only);
1536 void qemu_savevm_state_cleanup(void)
1538 SaveStateEntry *se;
1539 Error *local_err = NULL;
1541 if (precopy_notify(PRECOPY_NOTIFY_CLEANUP, &local_err)) {
1542 error_report_err(local_err);
1545 trace_savevm_state_cleanup();
1546 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1547 if (se->ops && se->ops->save_cleanup) {
1548 se->ops->save_cleanup(se->opaque);
1553 static int qemu_savevm_state(QEMUFile *f, Error **errp)
1555 int ret;
1556 MigrationState *ms = migrate_get_current();
1557 MigrationStatus status;
1559 if (migration_is_running(ms->state)) {
1560 error_setg(errp, QERR_MIGRATION_ACTIVE);
1561 return -EINVAL;
1564 if (migrate_use_block()) {
1565 error_setg(errp, "Block migration and snapshots are incompatible");
1566 return -EINVAL;
1569 migrate_init(ms);
1570 memset(&ram_counters, 0, sizeof(ram_counters));
1571 memset(&compression_counters, 0, sizeof(compression_counters));
1572 ms->to_dst_file = f;
1574 qemu_mutex_unlock_iothread();
1575 qemu_savevm_state_header(f);
1576 qemu_savevm_state_setup(f);
1577 qemu_mutex_lock_iothread();
1579 while (qemu_file_get_error(f) == 0) {
1580 if (qemu_savevm_state_iterate(f, false) > 0) {
1581 break;
1585 ret = qemu_file_get_error(f);
1586 if (ret == 0) {
1587 qemu_savevm_state_complete_precopy(f, false, false);
1588 ret = qemu_file_get_error(f);
1590 qemu_savevm_state_cleanup();
1591 if (ret != 0) {
1592 error_setg_errno(errp, -ret, "Error while writing VM state");
1595 if (ret != 0) {
1596 status = MIGRATION_STATUS_FAILED;
1597 } else {
1598 status = MIGRATION_STATUS_COMPLETED;
1600 migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status);
1602 /* f is outer parameter, it should not stay in global migration state after
1603 * this function finished */
1604 ms->to_dst_file = NULL;
1606 return ret;
1609 void qemu_savevm_live_state(QEMUFile *f)
1611 /* save QEMU_VM_SECTION_END section */
1612 qemu_savevm_state_complete_precopy(f, true, false);
1613 qemu_put_byte(f, QEMU_VM_EOF);
1616 int qemu_save_device_state(QEMUFile *f)
1618 SaveStateEntry *se;
1620 if (!migration_in_colo_state()) {
1621 qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
1622 qemu_put_be32(f, QEMU_VM_FILE_VERSION);
1624 cpu_synchronize_all_states();
1626 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1627 int ret;
1629 if (se->is_ram) {
1630 continue;
1632 if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
1633 continue;
1635 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
1636 continue;
1639 save_section_header(f, se, QEMU_VM_SECTION_FULL);
1641 ret = vmstate_save(f, se, NULL);
1642 if (ret) {
1643 return ret;
1646 save_section_footer(f, se);
1649 qemu_put_byte(f, QEMU_VM_EOF);
1651 return qemu_file_get_error(f);
1654 static SaveStateEntry *find_se(const char *idstr, uint32_t instance_id)
1656 SaveStateEntry *se;
1658 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
1659 if (!strcmp(se->idstr, idstr) &&
1660 (instance_id == se->instance_id ||
1661 instance_id == se->alias_id))
1662 return se;
1663 /* Migrating from an older version? */
1664 if (strstr(se->idstr, idstr) && se->compat) {
1665 if (!strcmp(se->compat->idstr, idstr) &&
1666 (instance_id == se->compat->instance_id ||
1667 instance_id == se->alias_id))
1668 return se;
1671 return NULL;
1674 enum LoadVMExitCodes {
1675 /* Allow a command to quit all layers of nested loadvm loops */
1676 LOADVM_QUIT = 1,
1679 /* ------ incoming postcopy messages ------ */
1680 /* 'advise' arrives before any transfers just to tell us that a postcopy
1681 * *might* happen - it might be skipped if precopy transferred everything
1682 * quickly.
1684 static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
1685 uint16_t len)
1687 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
1688 uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps;
1689 size_t page_size = qemu_target_page_size();
1690 Error *local_err = NULL;
1692 trace_loadvm_postcopy_handle_advise();
1693 if (ps != POSTCOPY_INCOMING_NONE) {
1694 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps);
1695 return -1;
1698 switch (len) {
1699 case 0:
1700 if (migrate_postcopy_ram()) {
1701 error_report("RAM postcopy is enabled but have 0 byte advise");
1702 return -EINVAL;
1704 return 0;
1705 case 8 + 8:
1706 if (!migrate_postcopy_ram()) {
1707 error_report("RAM postcopy is disabled but have 16 byte advise");
1708 return -EINVAL;
1710 break;
1711 default:
1712 error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len);
1713 return -EINVAL;
1716 if (!postcopy_ram_supported_by_host(mis)) {
1717 postcopy_state_set(POSTCOPY_INCOMING_NONE);
1718 return -1;
1721 remote_pagesize_summary = qemu_get_be64(mis->from_src_file);
1722 local_pagesize_summary = ram_pagesize_summary();
1724 if (remote_pagesize_summary != local_pagesize_summary) {
1726 * This detects two potential causes of mismatch:
1727 * a) A mismatch in host page sizes
1728 * Some combinations of mismatch are probably possible but it gets
1729 * a bit more complicated. In particular we need to place whole
1730 * host pages on the dest at once, and we need to ensure that we
1731 * handle dirtying to make sure we never end up sending part of
1732 * a hostpage on it's own.
1733 * b) The use of different huge page sizes on source/destination
1734 * a more fine grain test is performed during RAM block migration
1735 * but this test here causes a nice early clear failure, and
1736 * also fails when passed to an older qemu that doesn't
1737 * do huge pages.
1739 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
1740 " d=%" PRIx64 ")",
1741 remote_pagesize_summary, local_pagesize_summary);
1742 return -1;
1745 remote_tps = qemu_get_be64(mis->from_src_file);
1746 if (remote_tps != page_size) {
1748 * Again, some differences could be dealt with, but for now keep it
1749 * simple.
1751 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
1752 (int)remote_tps, page_size);
1753 return -1;
1756 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) {
1757 error_report_err(local_err);
1758 return -1;
1761 if (ram_postcopy_incoming_init(mis)) {
1762 return -1;
1765 return 0;
1768 /* After postcopy we will be told to throw some pages away since they're
1769 * dirty and will have to be demand fetched. Must happen before CPU is
1770 * started.
1771 * There can be 0..many of these messages, each encoding multiple pages.
1773 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
1774 uint16_t len)
1776 int tmp;
1777 char ramid[256];
1778 PostcopyState ps = postcopy_state_get();
1780 trace_loadvm_postcopy_ram_handle_discard();
1782 switch (ps) {
1783 case POSTCOPY_INCOMING_ADVISE:
1784 /* 1st discard */
1785 tmp = postcopy_ram_prepare_discard(mis);
1786 if (tmp) {
1787 return tmp;
1789 break;
1791 case POSTCOPY_INCOMING_DISCARD:
1792 /* Expected state */
1793 break;
1795 default:
1796 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
1797 ps);
1798 return -1;
1800 /* We're expecting a
1801 * Version (0)
1802 * a RAM ID string (length byte, name, 0 term)
1803 * then at least 1 16 byte chunk
1805 if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
1806 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
1807 return -1;
1810 tmp = qemu_get_byte(mis->from_src_file);
1811 if (tmp != postcopy_ram_discard_version) {
1812 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
1813 return -1;
1816 if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
1817 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
1818 return -1;
1820 tmp = qemu_get_byte(mis->from_src_file);
1821 if (tmp != 0) {
1822 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
1823 return -1;
1826 len -= 3 + strlen(ramid);
1827 if (len % 16) {
1828 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
1829 return -1;
1831 trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
1832 while (len) {
1833 uint64_t start_addr, block_length;
1834 start_addr = qemu_get_be64(mis->from_src_file);
1835 block_length = qemu_get_be64(mis->from_src_file);
1837 len -= 16;
1838 int ret = ram_discard_range(ramid, start_addr, block_length);
1839 if (ret) {
1840 return ret;
1843 trace_loadvm_postcopy_ram_handle_discard_end();
1845 return 0;
1849 * Triggered by a postcopy_listen command; this thread takes over reading
1850 * the input stream, leaving the main thread free to carry on loading the rest
1851 * of the device state (from RAM).
1852 * (TODO:This could do with being in a postcopy file - but there again it's
1853 * just another input loop, not that postcopy specific)
1855 static void *postcopy_ram_listen_thread(void *opaque)
1857 MigrationIncomingState *mis = migration_incoming_get_current();
1858 QEMUFile *f = mis->from_src_file;
1859 int load_res;
1860 MigrationState *migr = migrate_get_current();
1862 object_ref(OBJECT(migr));
1864 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
1865 MIGRATION_STATUS_POSTCOPY_ACTIVE);
1866 qemu_sem_post(&mis->thread_sync_sem);
1867 trace_postcopy_ram_listen_thread_start();
1869 rcu_register_thread();
1871 * Because we're a thread and not a coroutine we can't yield
1872 * in qemu_file, and thus we must be blocking now.
1874 qemu_file_set_blocking(f, true);
1875 load_res = qemu_loadvm_state_main(f, mis);
1878 * This is tricky, but, mis->from_src_file can change after it
1879 * returns, when postcopy recovery happened. In the future, we may
1880 * want a wrapper for the QEMUFile handle.
1882 f = mis->from_src_file;
1884 /* And non-blocking again so we don't block in any cleanup */
1885 qemu_file_set_blocking(f, false);
1887 trace_postcopy_ram_listen_thread_exit();
1888 if (load_res < 0) {
1889 qemu_file_set_error(f, load_res);
1890 dirty_bitmap_mig_cancel_incoming();
1891 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING &&
1892 !migrate_postcopy_ram() && migrate_dirty_bitmaps())
1894 error_report("%s: loadvm failed during postcopy: %d. All states "
1895 "are migrated except dirty bitmaps. Some dirty "
1896 "bitmaps may be lost, and present migrated dirty "
1897 "bitmaps are correctly migrated and valid.",
1898 __func__, load_res);
1899 load_res = 0; /* prevent further exit() */
1900 } else {
1901 error_report("%s: loadvm failed: %d", __func__, load_res);
1902 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1903 MIGRATION_STATUS_FAILED);
1906 if (load_res >= 0) {
1908 * This looks good, but it's possible that the device loading in the
1909 * main thread hasn't finished yet, and so we might not be in 'RUN'
1910 * state yet; wait for the end of the main thread.
1912 qemu_event_wait(&mis->main_thread_load_event);
1914 postcopy_ram_incoming_cleanup(mis);
1916 if (load_res < 0) {
1918 * If something went wrong then we have a bad state so exit;
1919 * depending how far we got it might be possible at this point
1920 * to leave the guest running and fire MCEs for pages that never
1921 * arrived as a desperate recovery step.
1923 rcu_unregister_thread();
1924 exit(EXIT_FAILURE);
1927 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
1928 MIGRATION_STATUS_COMPLETED);
1930 * If everything has worked fine, then the main thread has waited
1931 * for us to start, and we're the last use of the mis.
1932 * (If something broke then qemu will have to exit anyway since it's
1933 * got a bad migration state).
1935 migration_incoming_state_destroy();
1936 qemu_loadvm_state_cleanup();
1938 rcu_unregister_thread();
1939 mis->have_listen_thread = false;
1940 postcopy_state_set(POSTCOPY_INCOMING_END);
1942 object_unref(OBJECT(migr));
1944 return NULL;
1947 /* After this message we must be able to immediately receive postcopy data */
1948 static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
1950 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
1951 Error *local_err = NULL;
1953 trace_loadvm_postcopy_handle_listen("enter");
1955 if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
1956 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
1957 return -1;
1959 if (ps == POSTCOPY_INCOMING_ADVISE) {
1961 * A rare case, we entered listen without having to do any discards,
1962 * so do the setup that's normally done at the time of the 1st discard.
1964 if (migrate_postcopy_ram()) {
1965 postcopy_ram_prepare_discard(mis);
1969 trace_loadvm_postcopy_handle_listen("after discard");
1972 * Sensitise RAM - can now generate requests for blocks that don't exist
1973 * However, at this point the CPU shouldn't be running, and the IO
1974 * shouldn't be doing anything yet so don't actually expect requests
1976 if (migrate_postcopy_ram()) {
1977 if (postcopy_ram_incoming_setup(mis)) {
1978 postcopy_ram_incoming_cleanup(mis);
1979 return -1;
1983 trace_loadvm_postcopy_handle_listen("after uffd");
1985 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) {
1986 error_report_err(local_err);
1987 return -1;
1990 mis->have_listen_thread = true;
1991 postcopy_thread_create(mis, &mis->listen_thread, "postcopy/listen",
1992 postcopy_ram_listen_thread, QEMU_THREAD_DETACHED);
1993 trace_loadvm_postcopy_handle_listen("return");
1995 return 0;
1998 static void loadvm_postcopy_handle_run_bh(void *opaque)
2000 Error *local_err = NULL;
2001 MigrationIncomingState *mis = opaque;
2003 trace_loadvm_postcopy_handle_run_bh("enter");
2005 /* TODO we should move all of this lot into postcopy_ram.c or a shared code
2006 * in migration.c
2008 cpu_synchronize_all_post_init();
2010 trace_loadvm_postcopy_handle_run_bh("after cpu sync");
2012 qemu_announce_self(&mis->announce_timer, migrate_announce_params());
2014 trace_loadvm_postcopy_handle_run_bh("after announce");
2016 /* Make sure all file formats throw away their mutable metadata.
2017 * If we get an error here, just don't restart the VM yet. */
2018 bdrv_activate_all(&local_err);
2019 if (local_err) {
2020 error_report_err(local_err);
2021 local_err = NULL;
2022 autostart = false;
2025 trace_loadvm_postcopy_handle_run_bh("after invalidate cache");
2027 dirty_bitmap_mig_before_vm_start();
2029 if (autostart) {
2030 /* Hold onto your hats, starting the CPU */
2031 vm_start();
2032 } else {
2033 /* leave it paused and let management decide when to start the CPU */
2034 runstate_set(RUN_STATE_PAUSED);
2037 qemu_bh_delete(mis->bh);
2039 trace_loadvm_postcopy_handle_run_bh("return");
2042 /* After all discards we can start running and asking for pages */
2043 static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
2045 PostcopyState ps = postcopy_state_get();
2047 trace_loadvm_postcopy_handle_run();
2048 if (ps != POSTCOPY_INCOMING_LISTENING) {
2049 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
2050 return -1;
2053 postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
2054 mis->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, mis);
2055 qemu_bh_schedule(mis->bh);
2057 /* We need to finish reading the stream from the package
2058 * and also stop reading anything more from the stream that loaded the
2059 * package (since it's now being read by the listener thread).
2060 * LOADVM_QUIT will quit all the layers of nested loadvm loops.
2062 return LOADVM_QUIT;
2065 /* We must be with page_request_mutex held */
2066 static gboolean postcopy_sync_page_req(gpointer key, gpointer value,
2067 gpointer data)
2069 MigrationIncomingState *mis = data;
2070 void *host_addr = (void *) key;
2071 ram_addr_t rb_offset;
2072 RAMBlock *rb;
2073 int ret;
2075 rb = qemu_ram_block_from_host(host_addr, true, &rb_offset);
2076 if (!rb) {
2078 * This should _never_ happen. However be nice for a migrating VM to
2079 * not crash/assert. Post an error (note: intended to not use *_once
2080 * because we do want to see all the illegal addresses; and this can
2081 * never be triggered by the guest so we're safe) and move on next.
2083 error_report("%s: illegal host addr %p", __func__, host_addr);
2084 /* Try the next entry */
2085 return FALSE;
2088 ret = migrate_send_rp_message_req_pages(mis, rb, rb_offset);
2089 if (ret) {
2090 /* Please refer to above comment. */
2091 error_report("%s: send rp message failed for addr %p",
2092 __func__, host_addr);
2093 return FALSE;
2096 trace_postcopy_page_req_sync(host_addr);
2098 return FALSE;
2101 static void migrate_send_rp_req_pages_pending(MigrationIncomingState *mis)
2103 WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) {
2104 g_tree_foreach(mis->page_requested, postcopy_sync_page_req, mis);
2108 static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
2110 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
2111 error_report("%s: illegal resume received", __func__);
2112 /* Don't fail the load, only for this. */
2113 return 0;
2117 * Reset the last_rb before we resend any page req to source again, since
2118 * the source should have it reset already.
2120 mis->last_rb = NULL;
2123 * This means source VM is ready to resume the postcopy migration.
2125 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
2126 MIGRATION_STATUS_POSTCOPY_ACTIVE);
2128 trace_loadvm_postcopy_handle_resume();
2130 /* Tell source that "we are ready" */
2131 migrate_send_rp_resume_ack(mis, MIGRATION_RESUME_ACK_VALUE);
2134 * After a postcopy recovery, the source should have lost the postcopy
2135 * queue, or potentially the requested pages could have been lost during
2136 * the network down phase. Let's re-sync with the source VM by re-sending
2137 * all the pending pages that we eagerly need, so these threads won't get
2138 * blocked too long due to the recovery.
2140 * Without this procedure, the faulted destination VM threads (waiting for
2141 * page requests right before the postcopy is interrupted) can keep hanging
2142 * until the pages are sent by the source during the background copying of
2143 * pages, or another thread faulted on the same address accidentally.
2145 migrate_send_rp_req_pages_pending(mis);
2148 * It's time to switch state and release the fault thread to continue
2149 * service page faults. Note that this should be explicitly after the
2150 * above call to migrate_send_rp_req_pages_pending(). In short:
2151 * migrate_send_rp_message_req_pages() is not thread safe, yet.
2153 qemu_sem_post(&mis->postcopy_pause_sem_fault);
2155 return 0;
2159 * Immediately following this command is a blob of data containing an embedded
2160 * chunk of migration stream; read it and load it.
2162 * @mis: Incoming state
2163 * @length: Length of packaged data to read
2165 * Returns: Negative values on error
2168 static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
2170 int ret;
2171 size_t length;
2172 QIOChannelBuffer *bioc;
2174 length = qemu_get_be32(mis->from_src_file);
2175 trace_loadvm_handle_cmd_packaged(length);
2177 if (length > MAX_VM_CMD_PACKAGED_SIZE) {
2178 error_report("Unreasonably large packaged state: %zu", length);
2179 return -1;
2182 bioc = qio_channel_buffer_new(length);
2183 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-loadvm-buffer");
2184 ret = qemu_get_buffer(mis->from_src_file,
2185 bioc->data,
2186 length);
2187 if (ret != length) {
2188 object_unref(OBJECT(bioc));
2189 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
2190 ret, length);
2191 return (ret < 0) ? ret : -EAGAIN;
2193 bioc->usage += length;
2194 trace_loadvm_handle_cmd_packaged_received(ret);
2196 QEMUFile *packf = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
2198 ret = qemu_loadvm_state_main(packf, mis);
2199 trace_loadvm_handle_cmd_packaged_main(ret);
2200 qemu_fclose(packf);
2201 object_unref(OBJECT(bioc));
2203 return ret;
2207 * Handle request that source requests for recved_bitmap on
2208 * destination. Payload format:
2210 * len (1 byte) + ramblock_name (<255 bytes)
2212 static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
2213 uint16_t len)
2215 QEMUFile *file = mis->from_src_file;
2216 RAMBlock *rb;
2217 char block_name[256];
2218 size_t cnt;
2220 cnt = qemu_get_counted_string(file, block_name);
2221 if (!cnt) {
2222 error_report("%s: failed to read block name", __func__);
2223 return -EINVAL;
2226 /* Validate before using the data */
2227 if (qemu_file_get_error(file)) {
2228 return qemu_file_get_error(file);
2231 if (len != cnt + 1) {
2232 error_report("%s: invalid payload length (%d)", __func__, len);
2233 return -EINVAL;
2236 rb = qemu_ram_block_by_name(block_name);
2237 if (!rb) {
2238 error_report("%s: block '%s' not found", __func__, block_name);
2239 return -EINVAL;
2242 migrate_send_rp_recv_bitmap(mis, block_name);
2244 trace_loadvm_handle_recv_bitmap(block_name);
2246 return 0;
2249 static int loadvm_process_enable_colo(MigrationIncomingState *mis)
2251 int ret = migration_incoming_enable_colo();
2253 if (!ret) {
2254 ret = colo_init_ram_cache();
2255 if (ret) {
2256 migration_incoming_disable_colo();
2259 return ret;
2263 * Process an incoming 'QEMU_VM_COMMAND'
2264 * 0 just a normal return
2265 * LOADVM_QUIT All good, but exit the loop
2266 * <0 Error
2268 static int loadvm_process_command(QEMUFile *f)
2270 MigrationIncomingState *mis = migration_incoming_get_current();
2271 uint16_t cmd;
2272 uint16_t len;
2273 uint32_t tmp32;
2275 cmd = qemu_get_be16(f);
2276 len = qemu_get_be16(f);
2278 /* Check validity before continue processing of cmds */
2279 if (qemu_file_get_error(f)) {
2280 return qemu_file_get_error(f);
2283 if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) {
2284 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len);
2285 return -EINVAL;
2288 trace_loadvm_process_command(mig_cmd_args[cmd].name, len);
2290 if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) {
2291 error_report("%s received with bad length - expecting %zu, got %d",
2292 mig_cmd_args[cmd].name,
2293 (size_t)mig_cmd_args[cmd].len, len);
2294 return -ERANGE;
2297 switch (cmd) {
2298 case MIG_CMD_OPEN_RETURN_PATH:
2299 if (mis->to_src_file) {
2300 error_report("CMD_OPEN_RETURN_PATH called when RP already open");
2301 /* Not really a problem, so don't give up */
2302 return 0;
2304 mis->to_src_file = qemu_file_get_return_path(f);
2305 if (!mis->to_src_file) {
2306 error_report("CMD_OPEN_RETURN_PATH failed");
2307 return -1;
2309 break;
2311 case MIG_CMD_PING:
2312 tmp32 = qemu_get_be32(f);
2313 trace_loadvm_process_command_ping(tmp32);
2314 if (!mis->to_src_file) {
2315 error_report("CMD_PING (0x%x) received with no return path",
2316 tmp32);
2317 return -1;
2319 migrate_send_rp_pong(mis, tmp32);
2320 break;
2322 case MIG_CMD_PACKAGED:
2323 return loadvm_handle_cmd_packaged(mis);
2325 case MIG_CMD_POSTCOPY_ADVISE:
2326 return loadvm_postcopy_handle_advise(mis, len);
2328 case MIG_CMD_POSTCOPY_LISTEN:
2329 return loadvm_postcopy_handle_listen(mis);
2331 case MIG_CMD_POSTCOPY_RUN:
2332 return loadvm_postcopy_handle_run(mis);
2334 case MIG_CMD_POSTCOPY_RAM_DISCARD:
2335 return loadvm_postcopy_ram_handle_discard(mis, len);
2337 case MIG_CMD_POSTCOPY_RESUME:
2338 return loadvm_postcopy_handle_resume(mis);
2340 case MIG_CMD_RECV_BITMAP:
2341 return loadvm_handle_recv_bitmap(mis, len);
2343 case MIG_CMD_ENABLE_COLO:
2344 return loadvm_process_enable_colo(mis);
2347 return 0;
2351 * Read a footer off the wire and check that it matches the expected section
2353 * Returns: true if the footer was good
2354 * false if there is a problem (and calls error_report to say why)
2356 static bool check_section_footer(QEMUFile *f, SaveStateEntry *se)
2358 int ret;
2359 uint8_t read_mark;
2360 uint32_t read_section_id;
2362 if (!migrate_get_current()->send_section_footer) {
2363 /* No footer to check */
2364 return true;
2367 read_mark = qemu_get_byte(f);
2369 ret = qemu_file_get_error(f);
2370 if (ret) {
2371 error_report("%s: Read section footer failed: %d",
2372 __func__, ret);
2373 return false;
2376 if (read_mark != QEMU_VM_SECTION_FOOTER) {
2377 error_report("Missing section footer for %s", se->idstr);
2378 return false;
2381 read_section_id = qemu_get_be32(f);
2382 if (read_section_id != se->load_section_id) {
2383 error_report("Mismatched section id in footer for %s -"
2384 " read 0x%x expected 0x%x",
2385 se->idstr, read_section_id, se->load_section_id);
2386 return false;
2389 /* All good */
2390 return true;
2393 static int
2394 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
2396 uint32_t instance_id, version_id, section_id;
2397 SaveStateEntry *se;
2398 char idstr[256];
2399 int ret;
2401 /* Read section start */
2402 section_id = qemu_get_be32(f);
2403 if (!qemu_get_counted_string(f, idstr)) {
2404 error_report("Unable to read ID string for section %u",
2405 section_id);
2406 return -EINVAL;
2408 instance_id = qemu_get_be32(f);
2409 version_id = qemu_get_be32(f);
2411 ret = qemu_file_get_error(f);
2412 if (ret) {
2413 error_report("%s: Failed to read instance/version ID: %d",
2414 __func__, ret);
2415 return ret;
2418 trace_qemu_loadvm_state_section_startfull(section_id, idstr,
2419 instance_id, version_id);
2420 /* Find savevm section */
2421 se = find_se(idstr, instance_id);
2422 if (se == NULL) {
2423 error_report("Unknown savevm section or instance '%s' %"PRIu32". "
2424 "Make sure that your current VM setup matches your "
2425 "saved VM setup, including any hotplugged devices",
2426 idstr, instance_id);
2427 return -EINVAL;
2430 /* Validate version */
2431 if (version_id > se->version_id) {
2432 error_report("savevm: unsupported version %d for '%s' v%d",
2433 version_id, idstr, se->version_id);
2434 return -EINVAL;
2436 se->load_version_id = version_id;
2437 se->load_section_id = section_id;
2439 /* Validate if it is a device's state */
2440 if (xen_enabled() && se->is_ram) {
2441 error_report("loadvm: %s RAM loading not allowed on Xen", idstr);
2442 return -EINVAL;
2445 ret = vmstate_load(f, se);
2446 if (ret < 0) {
2447 error_report("error while loading state for instance 0x%"PRIx32" of"
2448 " device '%s'", instance_id, idstr);
2449 return ret;
2451 if (!check_section_footer(f, se)) {
2452 return -EINVAL;
2455 return 0;
2458 static int
2459 qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
2461 uint32_t section_id;
2462 SaveStateEntry *se;
2463 int ret;
2465 section_id = qemu_get_be32(f);
2467 ret = qemu_file_get_error(f);
2468 if (ret) {
2469 error_report("%s: Failed to read section ID: %d",
2470 __func__, ret);
2471 return ret;
2474 trace_qemu_loadvm_state_section_partend(section_id);
2475 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
2476 if (se->load_section_id == section_id) {
2477 break;
2480 if (se == NULL) {
2481 error_report("Unknown savevm section %d", section_id);
2482 return -EINVAL;
2485 ret = vmstate_load(f, se);
2486 if (ret < 0) {
2487 error_report("error while loading state section id %d(%s)",
2488 section_id, se->idstr);
2489 return ret;
2491 if (!check_section_footer(f, se)) {
2492 return -EINVAL;
2495 return 0;
2498 static int qemu_loadvm_state_header(QEMUFile *f)
2500 unsigned int v;
2501 int ret;
2503 v = qemu_get_be32(f);
2504 if (v != QEMU_VM_FILE_MAGIC) {
2505 error_report("Not a migration stream");
2506 return -EINVAL;
2509 v = qemu_get_be32(f);
2510 if (v == QEMU_VM_FILE_VERSION_COMPAT) {
2511 error_report("SaveVM v2 format is obsolete and don't work anymore");
2512 return -ENOTSUP;
2514 if (v != QEMU_VM_FILE_VERSION) {
2515 error_report("Unsupported migration stream version");
2516 return -ENOTSUP;
2519 if (migrate_get_current()->send_configuration) {
2520 if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
2521 error_report("Configuration section missing");
2522 qemu_loadvm_state_cleanup();
2523 return -EINVAL;
2525 ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
2527 if (ret) {
2528 qemu_loadvm_state_cleanup();
2529 return ret;
2532 return 0;
2535 static int qemu_loadvm_state_setup(QEMUFile *f)
2537 SaveStateEntry *se;
2538 int ret;
2540 trace_loadvm_state_setup();
2541 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
2542 if (!se->ops || !se->ops->load_setup) {
2543 continue;
2545 if (se->ops->is_active) {
2546 if (!se->ops->is_active(se->opaque)) {
2547 continue;
2551 ret = se->ops->load_setup(f, se->opaque);
2552 if (ret < 0) {
2553 qemu_file_set_error(f, ret);
2554 error_report("Load state of device %s failed", se->idstr);
2555 return ret;
2558 return 0;
2561 void qemu_loadvm_state_cleanup(void)
2563 SaveStateEntry *se;
2565 trace_loadvm_state_cleanup();
2566 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
2567 if (se->ops && se->ops->load_cleanup) {
2568 se->ops->load_cleanup(se->opaque);
2573 /* Return true if we should continue the migration, or false. */
2574 static bool postcopy_pause_incoming(MigrationIncomingState *mis)
2576 int i;
2579 * If network is interrupted, any temp page we received will be useless
2580 * because we didn't mark them as "received" in receivedmap. After a
2581 * proper recovery later (which will sync src dirty bitmap with receivedmap
2582 * on dest) these cached small pages will be resent again.
2584 for (i = 0; i < mis->postcopy_channels; i++) {
2585 postcopy_temp_page_reset(&mis->postcopy_tmp_pages[i]);
2588 trace_postcopy_pause_incoming();
2590 assert(migrate_postcopy_ram());
2593 * Unregister yank with either from/to src would work, since ioc behind it
2594 * is the same
2596 migration_ioc_unregister_yank_from_file(mis->from_src_file);
2598 assert(mis->from_src_file);
2599 qemu_file_shutdown(mis->from_src_file);
2600 qemu_fclose(mis->from_src_file);
2601 mis->from_src_file = NULL;
2603 assert(mis->to_src_file);
2604 qemu_file_shutdown(mis->to_src_file);
2605 qemu_mutex_lock(&mis->rp_mutex);
2606 qemu_fclose(mis->to_src_file);
2607 mis->to_src_file = NULL;
2608 qemu_mutex_unlock(&mis->rp_mutex);
2610 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
2611 MIGRATION_STATUS_POSTCOPY_PAUSED);
2613 /* Notify the fault thread for the invalidated file handle */
2614 postcopy_fault_thread_notify(mis);
2616 error_report("Detected IO failure for postcopy. "
2617 "Migration paused.");
2619 while (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
2620 qemu_sem_wait(&mis->postcopy_pause_sem_dst);
2623 trace_postcopy_pause_incoming_continued();
2625 return true;
2628 int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
2630 uint8_t section_type;
2631 int ret = 0;
2633 retry:
2634 while (true) {
2635 section_type = qemu_get_byte(f);
2637 if (qemu_file_get_error(f)) {
2638 ret = qemu_file_get_error(f);
2639 break;
2642 trace_qemu_loadvm_state_section(section_type);
2643 switch (section_type) {
2644 case QEMU_VM_SECTION_START:
2645 case QEMU_VM_SECTION_FULL:
2646 ret = qemu_loadvm_section_start_full(f, mis);
2647 if (ret < 0) {
2648 goto out;
2650 break;
2651 case QEMU_VM_SECTION_PART:
2652 case QEMU_VM_SECTION_END:
2653 ret = qemu_loadvm_section_part_end(f, mis);
2654 if (ret < 0) {
2655 goto out;
2657 break;
2658 case QEMU_VM_COMMAND:
2659 ret = loadvm_process_command(f);
2660 trace_qemu_loadvm_state_section_command(ret);
2661 if ((ret < 0) || (ret == LOADVM_QUIT)) {
2662 goto out;
2664 break;
2665 case QEMU_VM_EOF:
2666 /* This is the end of migration */
2667 goto out;
2668 default:
2669 error_report("Unknown savevm section type %d", section_type);
2670 ret = -EINVAL;
2671 goto out;
2675 out:
2676 if (ret < 0) {
2677 qemu_file_set_error(f, ret);
2679 /* Cancel bitmaps incoming regardless of recovery */
2680 dirty_bitmap_mig_cancel_incoming();
2683 * If we are during an active postcopy, then we pause instead
2684 * of bail out to at least keep the VM's dirty data. Note
2685 * that POSTCOPY_INCOMING_LISTENING stage is still not enough,
2686 * during which we're still receiving device states and we
2687 * still haven't yet started the VM on destination.
2689 * Only RAM postcopy supports recovery. Still, if RAM postcopy is
2690 * enabled, canceled bitmaps postcopy will not affect RAM postcopy
2691 * recovering.
2693 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING &&
2694 migrate_postcopy_ram() && postcopy_pause_incoming(mis)) {
2695 /* Reset f to point to the newly created channel */
2696 f = mis->from_src_file;
2697 goto retry;
2700 return ret;
2703 int qemu_loadvm_state(QEMUFile *f)
2705 MigrationIncomingState *mis = migration_incoming_get_current();
2706 Error *local_err = NULL;
2707 int ret;
2709 if (qemu_savevm_state_blocked(&local_err)) {
2710 error_report_err(local_err);
2711 return -EINVAL;
2714 ret = qemu_loadvm_state_header(f);
2715 if (ret) {
2716 return ret;
2719 if (qemu_loadvm_state_setup(f) != 0) {
2720 return -EINVAL;
2723 cpu_synchronize_all_pre_loadvm();
2725 ret = qemu_loadvm_state_main(f, mis);
2726 qemu_event_set(&mis->main_thread_load_event);
2728 trace_qemu_loadvm_state_post_main(ret);
2730 if (mis->have_listen_thread) {
2731 /* Listen thread still going, can't clean up yet */
2732 return ret;
2735 if (ret == 0) {
2736 ret = qemu_file_get_error(f);
2740 * Try to read in the VMDESC section as well, so that dumping tools that
2741 * intercept our migration stream have the chance to see it.
2744 /* We've got to be careful; if we don't read the data and just shut the fd
2745 * then the sender can error if we close while it's still sending.
2746 * We also mustn't read data that isn't there; some transports (RDMA)
2747 * will stall waiting for that data when the source has already closed.
2749 if (ret == 0 && should_send_vmdesc()) {
2750 uint8_t *buf;
2751 uint32_t size;
2752 uint8_t section_type = qemu_get_byte(f);
2754 if (section_type != QEMU_VM_VMDESCRIPTION) {
2755 error_report("Expected vmdescription section, but got %d",
2756 section_type);
2758 * It doesn't seem worth failing at this point since
2759 * we apparently have an otherwise valid VM state
2761 } else {
2762 buf = g_malloc(0x1000);
2763 size = qemu_get_be32(f);
2765 while (size > 0) {
2766 uint32_t read_chunk = MIN(size, 0x1000);
2767 qemu_get_buffer(f, buf, read_chunk);
2768 size -= read_chunk;
2770 g_free(buf);
2774 qemu_loadvm_state_cleanup();
2775 cpu_synchronize_all_post_init();
2777 return ret;
2780 int qemu_load_device_state(QEMUFile *f)
2782 MigrationIncomingState *mis = migration_incoming_get_current();
2783 int ret;
2785 /* Load QEMU_VM_SECTION_FULL section */
2786 ret = qemu_loadvm_state_main(f, mis);
2787 if (ret < 0) {
2788 error_report("Failed to load device state: %d", ret);
2789 return ret;
2792 cpu_synchronize_all_post_init();
2793 return 0;
2796 bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
2797 bool has_devices, strList *devices, Error **errp)
2799 BlockDriverState *bs;
2800 QEMUSnapshotInfo sn1, *sn = &sn1;
2801 int ret = -1, ret2;
2802 QEMUFile *f;
2803 int saved_vm_running;
2804 uint64_t vm_state_size;
2805 g_autoptr(GDateTime) now = g_date_time_new_now_local();
2806 AioContext *aio_context;
2808 GLOBAL_STATE_CODE();
2810 if (migration_is_blocked(errp)) {
2811 return false;
2814 if (!replay_can_snapshot()) {
2815 error_setg(errp, "Record/replay does not allow making snapshot "
2816 "right now. Try once more later.");
2817 return false;
2820 if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
2821 return false;
2824 /* Delete old snapshots of the same name */
2825 if (name) {
2826 if (overwrite) {
2827 if (bdrv_all_delete_snapshot(name, has_devices,
2828 devices, errp) < 0) {
2829 return false;
2831 } else {
2832 ret2 = bdrv_all_has_snapshot(name, has_devices, devices, errp);
2833 if (ret2 < 0) {
2834 return false;
2836 if (ret2 == 1) {
2837 error_setg(errp,
2838 "Snapshot '%s' already exists in one or more devices",
2839 name);
2840 return false;
2845 bs = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
2846 if (bs == NULL) {
2847 return false;
2849 aio_context = bdrv_get_aio_context(bs);
2851 saved_vm_running = runstate_is_running();
2853 ret = global_state_store();
2854 if (ret) {
2855 error_setg(errp, "Error saving global state");
2856 return false;
2858 vm_stop(RUN_STATE_SAVE_VM);
2860 bdrv_drain_all_begin();
2862 aio_context_acquire(aio_context);
2864 memset(sn, 0, sizeof(*sn));
2866 /* fill auxiliary fields */
2867 sn->date_sec = g_date_time_to_unix(now);
2868 sn->date_nsec = g_date_time_get_microsecond(now) * 1000;
2869 sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
2870 if (replay_mode != REPLAY_MODE_NONE) {
2871 sn->icount = replay_get_current_icount();
2872 } else {
2873 sn->icount = -1ULL;
2876 if (name) {
2877 pstrcpy(sn->name, sizeof(sn->name), name);
2878 } else {
2879 g_autofree char *autoname = g_date_time_format(now, "vm-%Y%m%d%H%M%S");
2880 pstrcpy(sn->name, sizeof(sn->name), autoname);
2883 /* save the VM state */
2884 f = qemu_fopen_bdrv(bs, 1);
2885 if (!f) {
2886 error_setg(errp, "Could not open VM state file");
2887 goto the_end;
2889 ret = qemu_savevm_state(f, errp);
2890 vm_state_size = qemu_ftell(f);
2891 ret2 = qemu_fclose(f);
2892 if (ret < 0) {
2893 goto the_end;
2895 if (ret2 < 0) {
2896 ret = ret2;
2897 goto the_end;
2900 /* The bdrv_all_create_snapshot() call that follows acquires the AioContext
2901 * for itself. BDRV_POLL_WHILE() does not support nested locking because
2902 * it only releases the lock once. Therefore synchronous I/O will deadlock
2903 * unless we release the AioContext before bdrv_all_create_snapshot().
2905 aio_context_release(aio_context);
2906 aio_context = NULL;
2908 ret = bdrv_all_create_snapshot(sn, bs, vm_state_size,
2909 has_devices, devices, errp);
2910 if (ret < 0) {
2911 bdrv_all_delete_snapshot(sn->name, has_devices, devices, NULL);
2912 goto the_end;
2915 ret = 0;
2917 the_end:
2918 if (aio_context) {
2919 aio_context_release(aio_context);
2922 bdrv_drain_all_end();
2924 if (saved_vm_running) {
2925 vm_start();
2927 return ret == 0;
2930 void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live,
2931 Error **errp)
2933 QEMUFile *f;
2934 QIOChannelFile *ioc;
2935 int saved_vm_running;
2936 int ret;
2938 if (!has_live) {
2939 /* live default to true so old version of Xen tool stack can have a
2940 * successful live migration */
2941 live = true;
2944 saved_vm_running = runstate_is_running();
2945 vm_stop(RUN_STATE_SAVE_VM);
2946 global_state_store_running();
2948 ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT | O_TRUNC,
2949 0660, errp);
2950 if (!ioc) {
2951 goto the_end;
2953 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-save-state");
2954 f = qemu_fopen_channel_output(QIO_CHANNEL(ioc));
2955 object_unref(OBJECT(ioc));
2956 ret = qemu_save_device_state(f);
2957 if (ret < 0 || qemu_fclose(f) < 0) {
2958 error_setg(errp, QERR_IO_ERROR);
2959 } else {
2960 /* libxl calls the QMP command "stop" before calling
2961 * "xen-save-devices-state" and in case of migration failure, libxl
2962 * would call "cont".
2963 * So call bdrv_inactivate_all (release locks) here to let the other
2964 * side of the migration take control of the images.
2966 if (live && !saved_vm_running) {
2967 ret = bdrv_inactivate_all();
2968 if (ret) {
2969 error_setg(errp, "%s: bdrv_inactivate_all() failed (%d)",
2970 __func__, ret);
2975 the_end:
2976 if (saved_vm_running) {
2977 vm_start();
2981 void qmp_xen_load_devices_state(const char *filename, Error **errp)
2983 QEMUFile *f;
2984 QIOChannelFile *ioc;
2985 int ret;
2987 /* Guest must be paused before loading the device state; the RAM state
2988 * will already have been loaded by xc
2990 if (runstate_is_running()) {
2991 error_setg(errp, "Cannot update device state while vm is running");
2992 return;
2994 vm_stop(RUN_STATE_RESTORE_VM);
2996 ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0, errp);
2997 if (!ioc) {
2998 return;
3000 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-load-state");
3001 f = qemu_fopen_channel_input(QIO_CHANNEL(ioc));
3002 object_unref(OBJECT(ioc));
3004 ret = qemu_loadvm_state(f);
3005 qemu_fclose(f);
3006 if (ret < 0) {
3007 error_setg(errp, QERR_IO_ERROR);
3009 migration_incoming_state_destroy();
3012 bool load_snapshot(const char *name, const char *vmstate,
3013 bool has_devices, strList *devices, Error **errp)
3015 BlockDriverState *bs_vm_state;
3016 QEMUSnapshotInfo sn;
3017 QEMUFile *f;
3018 int ret;
3019 AioContext *aio_context;
3020 MigrationIncomingState *mis = migration_incoming_get_current();
3022 if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
3023 return false;
3025 ret = bdrv_all_has_snapshot(name, has_devices, devices, errp);
3026 if (ret < 0) {
3027 return false;
3029 if (ret == 0) {
3030 error_setg(errp, "Snapshot '%s' does not exist in one or more devices",
3031 name);
3032 return false;
3035 bs_vm_state = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
3036 if (!bs_vm_state) {
3037 return false;
3039 aio_context = bdrv_get_aio_context(bs_vm_state);
3041 /* Don't even try to load empty VM states */
3042 aio_context_acquire(aio_context);
3043 ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
3044 aio_context_release(aio_context);
3045 if (ret < 0) {
3046 return false;
3047 } else if (sn.vm_state_size == 0) {
3048 error_setg(errp, "This is a disk-only snapshot. Revert to it "
3049 " offline using qemu-img");
3050 return false;
3054 * Flush the record/replay queue. Now the VM state is going
3055 * to change. Therefore we don't need to preserve its consistency
3057 replay_flush_events();
3059 /* Flush all IO requests so they don't interfere with the new state. */
3060 bdrv_drain_all_begin();
3062 ret = bdrv_all_goto_snapshot(name, has_devices, devices, errp);
3063 if (ret < 0) {
3064 goto err_drain;
3067 /* restore the VM state */
3068 f = qemu_fopen_bdrv(bs_vm_state, 0);
3069 if (!f) {
3070 error_setg(errp, "Could not open VM state file");
3071 goto err_drain;
3074 qemu_system_reset(SHUTDOWN_CAUSE_NONE);
3075 mis->from_src_file = f;
3077 if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
3078 ret = -EINVAL;
3079 goto err_drain;
3081 aio_context_acquire(aio_context);
3082 ret = qemu_loadvm_state(f);
3083 migration_incoming_state_destroy();
3084 aio_context_release(aio_context);
3086 bdrv_drain_all_end();
3088 if (ret < 0) {
3089 error_setg(errp, "Error %d while loading VM state", ret);
3090 return false;
3093 return true;
3095 err_drain:
3096 bdrv_drain_all_end();
3097 return false;
3100 bool delete_snapshot(const char *name, bool has_devices,
3101 strList *devices, Error **errp)
3103 if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
3104 return false;
3107 if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) {
3108 return false;
3111 return true;
3114 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
3116 qemu_ram_set_idstr(mr->ram_block,
3117 memory_region_name(mr), dev);
3118 qemu_ram_set_migratable(mr->ram_block);
3121 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
3123 qemu_ram_unset_idstr(mr->ram_block);
3124 qemu_ram_unset_migratable(mr->ram_block);
3127 void vmstate_register_ram_global(MemoryRegion *mr)
3129 vmstate_register_ram(mr, NULL);
3132 bool vmstate_check_only_migratable(const VMStateDescription *vmsd)
3134 /* check needed if --only-migratable is specified */
3135 if (!only_migratable) {
3136 return true;
3139 return !(vmsd && vmsd->unmigratable);
3142 typedef struct SnapshotJob {
3143 Job common;
3144 char *tag;
3145 char *vmstate;
3146 strList *devices;
3147 Coroutine *co;
3148 Error **errp;
3149 bool ret;
3150 } SnapshotJob;
3152 static void qmp_snapshot_job_free(SnapshotJob *s)
3154 g_free(s->tag);
3155 g_free(s->vmstate);
3156 qapi_free_strList(s->devices);
3160 static void snapshot_load_job_bh(void *opaque)
3162 Job *job = opaque;
3163 SnapshotJob *s = container_of(job, SnapshotJob, common);
3164 int orig_vm_running;
3166 job_progress_set_remaining(&s->common, 1);
3168 orig_vm_running = runstate_is_running();
3169 vm_stop(RUN_STATE_RESTORE_VM);
3171 s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp);
3172 if (s->ret && orig_vm_running) {
3173 vm_start();
3176 job_progress_update(&s->common, 1);
3178 qmp_snapshot_job_free(s);
3179 aio_co_wake(s->co);
3182 static void snapshot_save_job_bh(void *opaque)
3184 Job *job = opaque;
3185 SnapshotJob *s = container_of(job, SnapshotJob, common);
3187 job_progress_set_remaining(&s->common, 1);
3188 s->ret = save_snapshot(s->tag, false, s->vmstate,
3189 true, s->devices, s->errp);
3190 job_progress_update(&s->common, 1);
3192 qmp_snapshot_job_free(s);
3193 aio_co_wake(s->co);
3196 static void snapshot_delete_job_bh(void *opaque)
3198 Job *job = opaque;
3199 SnapshotJob *s = container_of(job, SnapshotJob, common);
3201 job_progress_set_remaining(&s->common, 1);
3202 s->ret = delete_snapshot(s->tag, true, s->devices, s->errp);
3203 job_progress_update(&s->common, 1);
3205 qmp_snapshot_job_free(s);
3206 aio_co_wake(s->co);
3209 static int coroutine_fn snapshot_save_job_run(Job *job, Error **errp)
3211 SnapshotJob *s = container_of(job, SnapshotJob, common);
3212 s->errp = errp;
3213 s->co = qemu_coroutine_self();
3214 aio_bh_schedule_oneshot(qemu_get_aio_context(),
3215 snapshot_save_job_bh, job);
3216 qemu_coroutine_yield();
3217 return s->ret ? 0 : -1;
3220 static int coroutine_fn snapshot_load_job_run(Job *job, Error **errp)
3222 SnapshotJob *s = container_of(job, SnapshotJob, common);
3223 s->errp = errp;
3224 s->co = qemu_coroutine_self();
3225 aio_bh_schedule_oneshot(qemu_get_aio_context(),
3226 snapshot_load_job_bh, job);
3227 qemu_coroutine_yield();
3228 return s->ret ? 0 : -1;
3231 static int coroutine_fn snapshot_delete_job_run(Job *job, Error **errp)
3233 SnapshotJob *s = container_of(job, SnapshotJob, common);
3234 s->errp = errp;
3235 s->co = qemu_coroutine_self();
3236 aio_bh_schedule_oneshot(qemu_get_aio_context(),
3237 snapshot_delete_job_bh, job);
3238 qemu_coroutine_yield();
3239 return s->ret ? 0 : -1;
3243 static const JobDriver snapshot_load_job_driver = {
3244 .instance_size = sizeof(SnapshotJob),
3245 .job_type = JOB_TYPE_SNAPSHOT_LOAD,
3246 .run = snapshot_load_job_run,
3249 static const JobDriver snapshot_save_job_driver = {
3250 .instance_size = sizeof(SnapshotJob),
3251 .job_type = JOB_TYPE_SNAPSHOT_SAVE,
3252 .run = snapshot_save_job_run,
3255 static const JobDriver snapshot_delete_job_driver = {
3256 .instance_size = sizeof(SnapshotJob),
3257 .job_type = JOB_TYPE_SNAPSHOT_DELETE,
3258 .run = snapshot_delete_job_run,
3262 void qmp_snapshot_save(const char *job_id,
3263 const char *tag,
3264 const char *vmstate,
3265 strList *devices,
3266 Error **errp)
3268 SnapshotJob *s;
3270 s = job_create(job_id, &snapshot_save_job_driver, NULL,
3271 qemu_get_aio_context(), JOB_MANUAL_DISMISS,
3272 NULL, NULL, errp);
3273 if (!s) {
3274 return;
3277 s->tag = g_strdup(tag);
3278 s->vmstate = g_strdup(vmstate);
3279 s->devices = QAPI_CLONE(strList, devices);
3281 job_start(&s->common);
3284 void qmp_snapshot_load(const char *job_id,
3285 const char *tag,
3286 const char *vmstate,
3287 strList *devices,
3288 Error **errp)
3290 SnapshotJob *s;
3292 s = job_create(job_id, &snapshot_load_job_driver, NULL,
3293 qemu_get_aio_context(), JOB_MANUAL_DISMISS,
3294 NULL, NULL, errp);
3295 if (!s) {
3296 return;
3299 s->tag = g_strdup(tag);
3300 s->vmstate = g_strdup(vmstate);
3301 s->devices = QAPI_CLONE(strList, devices);
3303 job_start(&s->common);
3306 void qmp_snapshot_delete(const char *job_id,
3307 const char *tag,
3308 strList *devices,
3309 Error **errp)
3311 SnapshotJob *s;
3313 s = job_create(job_id, &snapshot_delete_job_driver, NULL,
3314 qemu_get_aio_context(), JOB_MANUAL_DISMISS,
3315 NULL, NULL, errp);
3316 if (!s) {
3317 return;
3320 s->tag = g_strdup(tag);
3321 s->devices = QAPI_CLONE(strList, devices);
3323 job_start(&s->common);