1 /* 2 * QEMU System Emulator 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2009-2015 Red Hat Inc 6 * 7 * Authors: 8 * Juan Quintela <quintela@redhat.com> 9 * 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: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 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. 27 */ 28 29 #include "qemu/osdep.h" 30 #include "hw/boards.h" 31 #include "hw/xen/xen.h" 32 #include "net/net.h" 33 #include "migration.h" 34 #include "migration/snapshot.h" 35 #include "migration/vmstate.h" 36 #include "migration/misc.h" 37 #include "migration/register.h" 38 #include "migration/global_state.h" 39 #include "ram.h" 40 #include "qemu-file-channel.h" 41 #include "qemu-file.h" 42 #include "savevm.h" 43 #include "postcopy-ram.h" 44 #include "qapi/error.h" 45 #include "qapi/qapi-commands-migration.h" 46 #include "qapi/qapi-commands-misc.h" 47 #include "qapi/qmp/qerror.h" 48 #include "qemu/error-report.h" 49 #include "sysemu/cpus.h" 50 #include "exec/memory.h" 51 #include "exec/target_page.h" 52 #include "trace.h" 53 #include "qemu/iov.h" 54 #include "qemu/main-loop.h" 55 #include "block/snapshot.h" 56 #include "qemu/cutils.h" 57 #include "io/channel-buffer.h" 58 #include "io/channel-file.h" 59 #include "sysemu/replay.h" 60 #include "sysemu/sysemu.h" 61 #include "qjson.h" 62 #include "migration/colo.h" 63 #include "qemu/bitmap.h" 64 #include "net/announce.h" 65 66 const unsigned int postcopy_ram_discard_version = 0; 67 68 /* Subcommands for QEMU_VM_COMMAND */ 69 enum qemu_vm_cmd { 70 MIG_CMD_INVALID = 0, /* Must be 0 */ 71 MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */ 72 MIG_CMD_PING, /* Request a PONG on the RP */ 73 74 MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just 75 warn we might want to do PC */ 76 MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming 77 pages as it's running. */ 78 MIG_CMD_POSTCOPY_RUN, /* Start execution */ 79 80 MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that 81 were previously sent during 82 precopy but are dirty. */ 83 MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */ 84 MIG_CMD_ENABLE_COLO, /* Enable COLO */ 85 MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */ 86 MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */ 87 MIG_CMD_MAX 88 }; 89 90 #define MAX_VM_CMD_PACKAGED_SIZE UINT32_MAX 91 static struct mig_cmd_args { 92 ssize_t len; /* -1 = variable */ 93 const char *name; 94 } mig_cmd_args[] = { 95 [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" }, 96 [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" }, 97 [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" }, 98 [MIG_CMD_POSTCOPY_ADVISE] = { .len = -1, .name = "POSTCOPY_ADVISE" }, 99 [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" }, 100 [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" }, 101 [MIG_CMD_POSTCOPY_RAM_DISCARD] = { 102 .len = -1, .name = "POSTCOPY_RAM_DISCARD" }, 103 [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" }, 104 [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" }, 105 [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" }, 106 [MIG_CMD_MAX] = { .len = -1, .name = "MAX" }, 107 }; 108 109 /* Note for MIG_CMD_POSTCOPY_ADVISE: 110 * The format of arguments is depending on postcopy mode: 111 * - postcopy RAM only 112 * uint64_t host page size 113 * uint64_t taget page size 114 * 115 * - postcopy RAM and postcopy dirty bitmaps 116 * format is the same as for postcopy RAM only 117 * 118 * - postcopy dirty bitmaps only 119 * Nothing. Command length field is 0. 120 * 121 * Be careful: adding a new postcopy entity with some other parameters should 122 * not break format self-description ability. Good way is to introduce some 123 * generic extendable format with an exception for two old entities. 124 */ 125 126 /***********************************************************/ 127 /* savevm/loadvm support */ 128 129 static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, 130 int64_t pos) 131 { 132 int ret; 133 QEMUIOVector qiov; 134 135 qemu_iovec_init_external(&qiov, iov, iovcnt); 136 ret = bdrv_writev_vmstate(opaque, &qiov, pos); 137 if (ret < 0) { 138 return ret; 139 } 140 141 return qiov.size; 142 } 143 144 static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, 145 size_t size) 146 { 147 return bdrv_load_vmstate(opaque, buf, pos, size); 148 } 149 150 static int bdrv_fclose(void *opaque) 151 { 152 return bdrv_flush(opaque); 153 } 154 155 static const QEMUFileOps bdrv_read_ops = { 156 .get_buffer = block_get_buffer, 157 .close = bdrv_fclose 158 }; 159 160 static const QEMUFileOps bdrv_write_ops = { 161 .writev_buffer = block_writev_buffer, 162 .close = bdrv_fclose 163 }; 164 165 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable) 166 { 167 if (is_writable) { 168 return qemu_fopen_ops(bs, &bdrv_write_ops); 169 } 170 return qemu_fopen_ops(bs, &bdrv_read_ops); 171 } 172 173 174 /* QEMUFile timer support. 175 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c 176 */ 177 178 void timer_put(QEMUFile *f, QEMUTimer *ts) 179 { 180 uint64_t expire_time; 181 182 expire_time = timer_expire_time_ns(ts); 183 qemu_put_be64(f, expire_time); 184 } 185 186 void timer_get(QEMUFile *f, QEMUTimer *ts) 187 { 188 uint64_t expire_time; 189 190 expire_time = qemu_get_be64(f); 191 if (expire_time != -1) { 192 timer_mod_ns(ts, expire_time); 193 } else { 194 timer_del(ts); 195 } 196 } 197 198 199 /* VMState timer support. 200 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c 201 */ 202 203 static int get_timer(QEMUFile *f, void *pv, size_t size, 204 const VMStateField *field) 205 { 206 QEMUTimer *v = pv; 207 timer_get(f, v); 208 return 0; 209 } 210 211 static int put_timer(QEMUFile *f, void *pv, size_t size, 212 const VMStateField *field, QJSON *vmdesc) 213 { 214 QEMUTimer *v = pv; 215 timer_put(f, v); 216 217 return 0; 218 } 219 220 const VMStateInfo vmstate_info_timer = { 221 .name = "timer", 222 .get = get_timer, 223 .put = put_timer, 224 }; 225 226 227 typedef struct CompatEntry { 228 char idstr[256]; 229 int instance_id; 230 } CompatEntry; 231 232 typedef struct SaveStateEntry { 233 QTAILQ_ENTRY(SaveStateEntry) entry; 234 char idstr[256]; 235 int instance_id; 236 int alias_id; 237 int version_id; 238 /* version id read from the stream */ 239 int load_version_id; 240 int section_id; 241 /* section id read from the stream */ 242 int load_section_id; 243 const SaveVMHandlers *ops; 244 const VMStateDescription *vmsd; 245 void *opaque; 246 CompatEntry *compat; 247 int is_ram; 248 } SaveStateEntry; 249 250 typedef struct SaveState { 251 QTAILQ_HEAD(, SaveStateEntry) handlers; 252 int global_section_id; 253 uint32_t len; 254 const char *name; 255 uint32_t target_page_bits; 256 uint32_t caps_count; 257 MigrationCapability *capabilities; 258 } SaveState; 259 260 static SaveState savevm_state = { 261 .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers), 262 .global_section_id = 0, 263 }; 264 265 static bool should_validate_capability(int capability) 266 { 267 assert(capability >= 0 && capability < MIGRATION_CAPABILITY__MAX); 268 /* Validate only new capabilities to keep compatibility. */ 269 switch (capability) { 270 case MIGRATION_CAPABILITY_X_IGNORE_SHARED: 271 return true; 272 default: 273 return false; 274 } 275 } 276 277 static uint32_t get_validatable_capabilities_count(void) 278 { 279 MigrationState *s = migrate_get_current(); 280 uint32_t result = 0; 281 int i; 282 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 283 if (should_validate_capability(i) && s->enabled_capabilities[i]) { 284 result++; 285 } 286 } 287 return result; 288 } 289 290 static int configuration_pre_save(void *opaque) 291 { 292 SaveState *state = opaque; 293 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 294 MigrationState *s = migrate_get_current(); 295 int i, j; 296 297 state->len = strlen(current_name); 298 state->name = current_name; 299 state->target_page_bits = qemu_target_page_bits(); 300 301 state->caps_count = get_validatable_capabilities_count(); 302 state->capabilities = g_renew(MigrationCapability, state->capabilities, 303 state->caps_count); 304 for (i = j = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 305 if (should_validate_capability(i) && s->enabled_capabilities[i]) { 306 state->capabilities[j++] = i; 307 } 308 } 309 310 return 0; 311 } 312 313 static int configuration_pre_load(void *opaque) 314 { 315 SaveState *state = opaque; 316 317 /* If there is no target-page-bits subsection it means the source 318 * predates the variable-target-page-bits support and is using the 319 * minimum possible value for this CPU. 320 */ 321 state->target_page_bits = qemu_target_page_bits_min(); 322 return 0; 323 } 324 325 static bool configuration_validate_capabilities(SaveState *state) 326 { 327 bool ret = true; 328 MigrationState *s = migrate_get_current(); 329 unsigned long *source_caps_bm; 330 int i; 331 332 source_caps_bm = bitmap_new(MIGRATION_CAPABILITY__MAX); 333 for (i = 0; i < state->caps_count; i++) { 334 MigrationCapability capability = state->capabilities[i]; 335 set_bit(capability, source_caps_bm); 336 } 337 338 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 339 bool source_state, target_state; 340 if (!should_validate_capability(i)) { 341 continue; 342 } 343 source_state = test_bit(i, source_caps_bm); 344 target_state = s->enabled_capabilities[i]; 345 if (source_state != target_state) { 346 error_report("Capability %s is %s, but received capability is %s", 347 MigrationCapability_str(i), 348 target_state ? "on" : "off", 349 source_state ? "on" : "off"); 350 ret = false; 351 /* Don't break here to report all failed capabilities */ 352 } 353 } 354 355 g_free(source_caps_bm); 356 return ret; 357 } 358 359 static int configuration_post_load(void *opaque, int version_id) 360 { 361 SaveState *state = opaque; 362 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 363 364 if (strncmp(state->name, current_name, state->len) != 0) { 365 error_report("Machine type received is '%.*s' and local is '%s'", 366 (int) state->len, state->name, current_name); 367 return -EINVAL; 368 } 369 370 if (state->target_page_bits != qemu_target_page_bits()) { 371 error_report("Received TARGET_PAGE_BITS is %d but local is %d", 372 state->target_page_bits, qemu_target_page_bits()); 373 return -EINVAL; 374 } 375 376 if (!configuration_validate_capabilities(state)) { 377 return -EINVAL; 378 } 379 380 return 0; 381 } 382 383 static int get_capability(QEMUFile *f, void *pv, size_t size, 384 const VMStateField *field) 385 { 386 MigrationCapability *capability = pv; 387 char capability_str[UINT8_MAX + 1]; 388 uint8_t len; 389 int i; 390 391 len = qemu_get_byte(f); 392 qemu_get_buffer(f, (uint8_t *)capability_str, len); 393 capability_str[len] = '\0'; 394 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 395 if (!strcmp(MigrationCapability_str(i), capability_str)) { 396 *capability = i; 397 return 0; 398 } 399 } 400 error_report("Received unknown capability %s", capability_str); 401 return -EINVAL; 402 } 403 404 static int put_capability(QEMUFile *f, void *pv, size_t size, 405 const VMStateField *field, QJSON *vmdesc) 406 { 407 MigrationCapability *capability = pv; 408 const char *capability_str = MigrationCapability_str(*capability); 409 size_t len = strlen(capability_str); 410 assert(len <= UINT8_MAX); 411 412 qemu_put_byte(f, len); 413 qemu_put_buffer(f, (uint8_t *)capability_str, len); 414 return 0; 415 } 416 417 static const VMStateInfo vmstate_info_capability = { 418 .name = "capability", 419 .get = get_capability, 420 .put = put_capability, 421 }; 422 423 /* The target-page-bits subsection is present only if the 424 * target page size is not the same as the default (ie the 425 * minimum page size for a variable-page-size guest CPU). 426 * If it is present then it contains the actual target page 427 * bits for the machine, and migration will fail if the 428 * two ends don't agree about it. 429 */ 430 static bool vmstate_target_page_bits_needed(void *opaque) 431 { 432 return qemu_target_page_bits() 433 > qemu_target_page_bits_min(); 434 } 435 436 static const VMStateDescription vmstate_target_page_bits = { 437 .name = "configuration/target-page-bits", 438 .version_id = 1, 439 .minimum_version_id = 1, 440 .needed = vmstate_target_page_bits_needed, 441 .fields = (VMStateField[]) { 442 VMSTATE_UINT32(target_page_bits, SaveState), 443 VMSTATE_END_OF_LIST() 444 } 445 }; 446 447 static bool vmstate_capabilites_needed(void *opaque) 448 { 449 return get_validatable_capabilities_count() > 0; 450 } 451 452 static const VMStateDescription vmstate_capabilites = { 453 .name = "configuration/capabilities", 454 .version_id = 1, 455 .minimum_version_id = 1, 456 .needed = vmstate_capabilites_needed, 457 .fields = (VMStateField[]) { 458 VMSTATE_UINT32_V(caps_count, SaveState, 1), 459 VMSTATE_VARRAY_UINT32_ALLOC(capabilities, SaveState, caps_count, 1, 460 vmstate_info_capability, 461 MigrationCapability), 462 VMSTATE_END_OF_LIST() 463 } 464 }; 465 466 static const VMStateDescription vmstate_configuration = { 467 .name = "configuration", 468 .version_id = 1, 469 .pre_load = configuration_pre_load, 470 .post_load = configuration_post_load, 471 .pre_save = configuration_pre_save, 472 .fields = (VMStateField[]) { 473 VMSTATE_UINT32(len, SaveState), 474 VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len), 475 VMSTATE_END_OF_LIST() 476 }, 477 .subsections = (const VMStateDescription*[]) { 478 &vmstate_target_page_bits, 479 &vmstate_capabilites, 480 NULL 481 } 482 }; 483 484 static void dump_vmstate_vmsd(FILE *out_file, 485 const VMStateDescription *vmsd, int indent, 486 bool is_subsection); 487 488 static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field, 489 int indent) 490 { 491 fprintf(out_file, "%*s{\n", indent, ""); 492 indent += 2; 493 fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name); 494 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 495 field->version_id); 496 fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "", 497 field->field_exists ? "true" : "false"); 498 fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size); 499 if (field->vmsd != NULL) { 500 fprintf(out_file, ",\n"); 501 dump_vmstate_vmsd(out_file, field->vmsd, indent, false); 502 } 503 fprintf(out_file, "\n%*s}", indent - 2, ""); 504 } 505 506 static void dump_vmstate_vmss(FILE *out_file, 507 const VMStateDescription **subsection, 508 int indent) 509 { 510 if (*subsection != NULL) { 511 dump_vmstate_vmsd(out_file, *subsection, indent, true); 512 } 513 } 514 515 static void dump_vmstate_vmsd(FILE *out_file, 516 const VMStateDescription *vmsd, int indent, 517 bool is_subsection) 518 { 519 if (is_subsection) { 520 fprintf(out_file, "%*s{\n", indent, ""); 521 } else { 522 fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description"); 523 } 524 indent += 2; 525 fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name); 526 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 527 vmsd->version_id); 528 fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "", 529 vmsd->minimum_version_id); 530 if (vmsd->fields != NULL) { 531 const VMStateField *field = vmsd->fields; 532 bool first; 533 534 fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, ""); 535 first = true; 536 while (field->name != NULL) { 537 if (field->flags & VMS_MUST_EXIST) { 538 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */ 539 field++; 540 continue; 541 } 542 if (!first) { 543 fprintf(out_file, ",\n"); 544 } 545 dump_vmstate_vmsf(out_file, field, indent + 2); 546 field++; 547 first = false; 548 } 549 fprintf(out_file, "\n%*s]", indent, ""); 550 } 551 if (vmsd->subsections != NULL) { 552 const VMStateDescription **subsection = vmsd->subsections; 553 bool first; 554 555 fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, ""); 556 first = true; 557 while (*subsection != NULL) { 558 if (!first) { 559 fprintf(out_file, ",\n"); 560 } 561 dump_vmstate_vmss(out_file, subsection, indent + 2); 562 subsection++; 563 first = false; 564 } 565 fprintf(out_file, "\n%*s]", indent, ""); 566 } 567 fprintf(out_file, "\n%*s}", indent - 2, ""); 568 } 569 570 static void dump_machine_type(FILE *out_file) 571 { 572 MachineClass *mc; 573 574 mc = MACHINE_GET_CLASS(current_machine); 575 576 fprintf(out_file, " \"vmschkmachine\": {\n"); 577 fprintf(out_file, " \"Name\": \"%s\"\n", mc->name); 578 fprintf(out_file, " },\n"); 579 } 580 581 void dump_vmstate_json_to_file(FILE *out_file) 582 { 583 GSList *list, *elt; 584 bool first; 585 586 fprintf(out_file, "{\n"); 587 dump_machine_type(out_file); 588 589 first = true; 590 list = object_class_get_list(TYPE_DEVICE, true); 591 for (elt = list; elt; elt = elt->next) { 592 DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data, 593 TYPE_DEVICE); 594 const char *name; 595 int indent = 2; 596 597 if (!dc->vmsd) { 598 continue; 599 } 600 601 if (!first) { 602 fprintf(out_file, ",\n"); 603 } 604 name = object_class_get_name(OBJECT_CLASS(dc)); 605 fprintf(out_file, "%*s\"%s\": {\n", indent, "", name); 606 indent += 2; 607 fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name); 608 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 609 dc->vmsd->version_id); 610 fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "", 611 dc->vmsd->minimum_version_id); 612 613 dump_vmstate_vmsd(out_file, dc->vmsd, indent, false); 614 615 fprintf(out_file, "\n%*s}", indent - 2, ""); 616 first = false; 617 } 618 fprintf(out_file, "\n}\n"); 619 fclose(out_file); 620 } 621 622 static int calculate_new_instance_id(const char *idstr) 623 { 624 SaveStateEntry *se; 625 int instance_id = 0; 626 627 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 628 if (strcmp(idstr, se->idstr) == 0 629 && instance_id <= se->instance_id) { 630 instance_id = se->instance_id + 1; 631 } 632 } 633 return instance_id; 634 } 635 636 static int calculate_compat_instance_id(const char *idstr) 637 { 638 SaveStateEntry *se; 639 int instance_id = 0; 640 641 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 642 if (!se->compat) { 643 continue; 644 } 645 646 if (strcmp(idstr, se->compat->idstr) == 0 647 && instance_id <= se->compat->instance_id) { 648 instance_id = se->compat->instance_id + 1; 649 } 650 } 651 return instance_id; 652 } 653 654 static inline MigrationPriority save_state_priority(SaveStateEntry *se) 655 { 656 if (se->vmsd) { 657 return se->vmsd->priority; 658 } 659 return MIG_PRI_DEFAULT; 660 } 661 662 static void savevm_state_handler_insert(SaveStateEntry *nse) 663 { 664 MigrationPriority priority = save_state_priority(nse); 665 SaveStateEntry *se; 666 667 assert(priority <= MIG_PRI_MAX); 668 669 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 670 if (save_state_priority(se) < priority) { 671 break; 672 } 673 } 674 675 if (se) { 676 QTAILQ_INSERT_BEFORE(se, nse, entry); 677 } else { 678 QTAILQ_INSERT_TAIL(&savevm_state.handlers, nse, entry); 679 } 680 } 681 682 /* TODO: Individual devices generally have very little idea about the rest 683 of the system, so instance_id should be removed/replaced. 684 Meanwhile pass -1 as instance_id if you do not already have a clearly 685 distinguishing id for all instances of your device class. */ 686 int register_savevm_live(DeviceState *dev, 687 const char *idstr, 688 int instance_id, 689 int version_id, 690 const SaveVMHandlers *ops, 691 void *opaque) 692 { 693 SaveStateEntry *se; 694 695 se = g_new0(SaveStateEntry, 1); 696 se->version_id = version_id; 697 se->section_id = savevm_state.global_section_id++; 698 se->ops = ops; 699 se->opaque = opaque; 700 se->vmsd = NULL; 701 /* if this is a live_savem then set is_ram */ 702 if (ops->save_setup != NULL) { 703 se->is_ram = 1; 704 } 705 706 if (dev) { 707 char *id = qdev_get_dev_path(dev); 708 if (id) { 709 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 710 sizeof(se->idstr)) { 711 error_report("Path too long for VMState (%s)", id); 712 g_free(id); 713 g_free(se); 714 715 return -1; 716 } 717 g_free(id); 718 719 se->compat = g_new0(CompatEntry, 1); 720 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr); 721 se->compat->instance_id = instance_id == -1 ? 722 calculate_compat_instance_id(idstr) : instance_id; 723 instance_id = -1; 724 } 725 } 726 pstrcat(se->idstr, sizeof(se->idstr), idstr); 727 728 if (instance_id == -1) { 729 se->instance_id = calculate_new_instance_id(se->idstr); 730 } else { 731 se->instance_id = instance_id; 732 } 733 assert(!se->compat || se->instance_id == 0); 734 savevm_state_handler_insert(se); 735 return 0; 736 } 737 738 void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque) 739 { 740 SaveStateEntry *se, *new_se; 741 char id[256] = ""; 742 743 if (dev) { 744 char *path = qdev_get_dev_path(dev); 745 if (path) { 746 pstrcpy(id, sizeof(id), path); 747 pstrcat(id, sizeof(id), "/"); 748 g_free(path); 749 } 750 } 751 pstrcat(id, sizeof(id), idstr); 752 753 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 754 if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) { 755 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 756 g_free(se->compat); 757 g_free(se); 758 } 759 } 760 } 761 762 int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, 763 const VMStateDescription *vmsd, 764 void *opaque, int alias_id, 765 int required_for_version, 766 Error **errp) 767 { 768 SaveStateEntry *se; 769 770 /* If this triggers, alias support can be dropped for the vmsd. */ 771 assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id); 772 773 se = g_new0(SaveStateEntry, 1); 774 se->version_id = vmsd->version_id; 775 se->section_id = savevm_state.global_section_id++; 776 se->opaque = opaque; 777 se->vmsd = vmsd; 778 se->alias_id = alias_id; 779 780 if (dev) { 781 char *id = qdev_get_dev_path(dev); 782 if (id) { 783 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 784 sizeof(se->idstr)) { 785 error_setg(errp, "Path too long for VMState (%s)", id); 786 g_free(id); 787 g_free(se); 788 789 return -1; 790 } 791 g_free(id); 792 793 se->compat = g_new0(CompatEntry, 1); 794 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name); 795 se->compat->instance_id = instance_id == -1 ? 796 calculate_compat_instance_id(vmsd->name) : instance_id; 797 instance_id = -1; 798 } 799 } 800 pstrcat(se->idstr, sizeof(se->idstr), vmsd->name); 801 802 if (instance_id == -1) { 803 se->instance_id = calculate_new_instance_id(se->idstr); 804 } else { 805 se->instance_id = instance_id; 806 } 807 assert(!se->compat || se->instance_id == 0); 808 savevm_state_handler_insert(se); 809 return 0; 810 } 811 812 void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd, 813 void *opaque) 814 { 815 SaveStateEntry *se, *new_se; 816 817 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 818 if (se->vmsd == vmsd && se->opaque == opaque) { 819 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 820 g_free(se->compat); 821 g_free(se); 822 } 823 } 824 } 825 826 static int vmstate_load(QEMUFile *f, SaveStateEntry *se) 827 { 828 trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 829 if (!se->vmsd) { /* Old style */ 830 return se->ops->load_state(f, se->opaque, se->load_version_id); 831 } 832 return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id); 833 } 834 835 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc) 836 { 837 int64_t old_offset, size; 838 839 old_offset = qemu_ftell_fast(f); 840 se->ops->save_state(f, se->opaque); 841 size = qemu_ftell_fast(f) - old_offset; 842 843 if (vmdesc) { 844 json_prop_int(vmdesc, "size", size); 845 json_start_array(vmdesc, "fields"); 846 json_start_object(vmdesc, NULL); 847 json_prop_str(vmdesc, "name", "data"); 848 json_prop_int(vmdesc, "size", size); 849 json_prop_str(vmdesc, "type", "buffer"); 850 json_end_object(vmdesc); 851 json_end_array(vmdesc); 852 } 853 } 854 855 static int vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc) 856 { 857 trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 858 if (!se->vmsd) { 859 vmstate_save_old_style(f, se, vmdesc); 860 return 0; 861 } 862 return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc); 863 } 864 865 /* 866 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL) 867 */ 868 static void save_section_header(QEMUFile *f, SaveStateEntry *se, 869 uint8_t section_type) 870 { 871 qemu_put_byte(f, section_type); 872 qemu_put_be32(f, se->section_id); 873 874 if (section_type == QEMU_VM_SECTION_FULL || 875 section_type == QEMU_VM_SECTION_START) { 876 /* ID string */ 877 size_t len = strlen(se->idstr); 878 qemu_put_byte(f, len); 879 qemu_put_buffer(f, (uint8_t *)se->idstr, len); 880 881 qemu_put_be32(f, se->instance_id); 882 qemu_put_be32(f, se->version_id); 883 } 884 } 885 886 /* 887 * Write a footer onto device sections that catches cases misformatted device 888 * sections. 889 */ 890 static void save_section_footer(QEMUFile *f, SaveStateEntry *se) 891 { 892 if (migrate_get_current()->send_section_footer) { 893 qemu_put_byte(f, QEMU_VM_SECTION_FOOTER); 894 qemu_put_be32(f, se->section_id); 895 } 896 } 897 898 /** 899 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the 900 * command and associated data. 901 * 902 * @f: File to send command on 903 * @command: Command type to send 904 * @len: Length of associated data 905 * @data: Data associated with command. 906 */ 907 static void qemu_savevm_command_send(QEMUFile *f, 908 enum qemu_vm_cmd command, 909 uint16_t len, 910 uint8_t *data) 911 { 912 trace_savevm_command_send(command, len); 913 qemu_put_byte(f, QEMU_VM_COMMAND); 914 qemu_put_be16(f, (uint16_t)command); 915 qemu_put_be16(f, len); 916 qemu_put_buffer(f, data, len); 917 qemu_fflush(f); 918 } 919 920 void qemu_savevm_send_colo_enable(QEMUFile *f) 921 { 922 trace_savevm_send_colo_enable(); 923 qemu_savevm_command_send(f, MIG_CMD_ENABLE_COLO, 0, NULL); 924 } 925 926 void qemu_savevm_send_ping(QEMUFile *f, uint32_t value) 927 { 928 uint32_t buf; 929 930 trace_savevm_send_ping(value); 931 buf = cpu_to_be32(value); 932 qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf); 933 } 934 935 void qemu_savevm_send_open_return_path(QEMUFile *f) 936 { 937 trace_savevm_send_open_return_path(); 938 qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL); 939 } 940 941 /* We have a buffer of data to send; we don't want that all to be loaded 942 * by the command itself, so the command contains just the length of the 943 * extra buffer that we then send straight after it. 944 * TODO: Must be a better way to organise that 945 * 946 * Returns: 947 * 0 on success 948 * -ve on error 949 */ 950 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len) 951 { 952 uint32_t tmp; 953 954 if (len > MAX_VM_CMD_PACKAGED_SIZE) { 955 error_report("%s: Unreasonably large packaged state: %zu", 956 __func__, len); 957 return -1; 958 } 959 960 tmp = cpu_to_be32(len); 961 962 trace_qemu_savevm_send_packaged(); 963 qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp); 964 965 qemu_put_buffer(f, buf, len); 966 967 return 0; 968 } 969 970 /* Send prior to any postcopy transfer */ 971 void qemu_savevm_send_postcopy_advise(QEMUFile *f) 972 { 973 if (migrate_postcopy_ram()) { 974 uint64_t tmp[2]; 975 tmp[0] = cpu_to_be64(ram_pagesize_summary()); 976 tmp[1] = cpu_to_be64(qemu_target_page_size()); 977 978 trace_qemu_savevm_send_postcopy_advise(); 979 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 980 16, (uint8_t *)tmp); 981 } else { 982 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 0, NULL); 983 } 984 } 985 986 /* Sent prior to starting the destination running in postcopy, discard pages 987 * that have already been sent but redirtied on the source. 988 * CMD_POSTCOPY_RAM_DISCARD consist of: 989 * byte version (0) 990 * byte Length of name field (not including 0) 991 * n x byte RAM block name 992 * byte 0 terminator (just for safety) 993 * n x Byte ranges within the named RAMBlock 994 * be64 Start of the range 995 * be64 Length 996 * 997 * name: RAMBlock name that these entries are part of 998 * len: Number of page entries 999 * start_list: 'len' addresses 1000 * length_list: 'len' addresses 1001 * 1002 */ 1003 void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name, 1004 uint16_t len, 1005 uint64_t *start_list, 1006 uint64_t *length_list) 1007 { 1008 uint8_t *buf; 1009 uint16_t tmplen; 1010 uint16_t t; 1011 size_t name_len = strlen(name); 1012 1013 trace_qemu_savevm_send_postcopy_ram_discard(name, len); 1014 assert(name_len < 256); 1015 buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len); 1016 buf[0] = postcopy_ram_discard_version; 1017 buf[1] = name_len; 1018 memcpy(buf + 2, name, name_len); 1019 tmplen = 2 + name_len; 1020 buf[tmplen++] = '\0'; 1021 1022 for (t = 0; t < len; t++) { 1023 stq_be_p(buf + tmplen, start_list[t]); 1024 tmplen += 8; 1025 stq_be_p(buf + tmplen, length_list[t]); 1026 tmplen += 8; 1027 } 1028 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf); 1029 g_free(buf); 1030 } 1031 1032 /* Get the destination into a state where it can receive postcopy data. */ 1033 void qemu_savevm_send_postcopy_listen(QEMUFile *f) 1034 { 1035 trace_savevm_send_postcopy_listen(); 1036 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL); 1037 } 1038 1039 /* Kick the destination into running */ 1040 void qemu_savevm_send_postcopy_run(QEMUFile *f) 1041 { 1042 trace_savevm_send_postcopy_run(); 1043 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL); 1044 } 1045 1046 void qemu_savevm_send_postcopy_resume(QEMUFile *f) 1047 { 1048 trace_savevm_send_postcopy_resume(); 1049 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL); 1050 } 1051 1052 void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name) 1053 { 1054 size_t len; 1055 char buf[256]; 1056 1057 trace_savevm_send_recv_bitmap(block_name); 1058 1059 buf[0] = len = strlen(block_name); 1060 memcpy(buf + 1, block_name, len); 1061 1062 qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf); 1063 } 1064 1065 bool qemu_savevm_state_blocked(Error **errp) 1066 { 1067 SaveStateEntry *se; 1068 1069 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1070 if (se->vmsd && se->vmsd->unmigratable) { 1071 error_setg(errp, "State blocked by non-migratable device '%s'", 1072 se->idstr); 1073 return true; 1074 } 1075 } 1076 return false; 1077 } 1078 1079 void qemu_savevm_state_header(QEMUFile *f) 1080 { 1081 trace_savevm_state_header(); 1082 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1083 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1084 1085 if (migrate_get_current()->send_configuration) { 1086 qemu_put_byte(f, QEMU_VM_CONFIGURATION); 1087 vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0); 1088 } 1089 } 1090 1091 void qemu_savevm_state_setup(QEMUFile *f) 1092 { 1093 SaveStateEntry *se; 1094 Error *local_err = NULL; 1095 int ret; 1096 1097 trace_savevm_state_setup(); 1098 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1099 if (!se->ops || !se->ops->save_setup) { 1100 continue; 1101 } 1102 if (se->ops && se->ops->is_active) { 1103 if (!se->ops->is_active(se->opaque)) { 1104 continue; 1105 } 1106 } 1107 save_section_header(f, se, QEMU_VM_SECTION_START); 1108 1109 ret = se->ops->save_setup(f, se->opaque); 1110 save_section_footer(f, se); 1111 if (ret < 0) { 1112 qemu_file_set_error(f, ret); 1113 break; 1114 } 1115 } 1116 1117 if (precopy_notify(PRECOPY_NOTIFY_SETUP, &local_err)) { 1118 error_report_err(local_err); 1119 } 1120 } 1121 1122 int qemu_savevm_state_resume_prepare(MigrationState *s) 1123 { 1124 SaveStateEntry *se; 1125 int ret; 1126 1127 trace_savevm_state_resume_prepare(); 1128 1129 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1130 if (!se->ops || !se->ops->resume_prepare) { 1131 continue; 1132 } 1133 if (se->ops && se->ops->is_active) { 1134 if (!se->ops->is_active(se->opaque)) { 1135 continue; 1136 } 1137 } 1138 ret = se->ops->resume_prepare(s, se->opaque); 1139 if (ret < 0) { 1140 return ret; 1141 } 1142 } 1143 1144 return 0; 1145 } 1146 1147 /* 1148 * this function has three return values: 1149 * negative: there was one error, and we have -errno. 1150 * 0 : We haven't finished, caller have to go again 1151 * 1 : We have finished, we can go to complete phase 1152 */ 1153 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy) 1154 { 1155 SaveStateEntry *se; 1156 int ret = 1; 1157 1158 trace_savevm_state_iterate(); 1159 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1160 if (!se->ops || !se->ops->save_live_iterate) { 1161 continue; 1162 } 1163 if (se->ops->is_active && 1164 !se->ops->is_active(se->opaque)) { 1165 continue; 1166 } 1167 if (se->ops->is_active_iterate && 1168 !se->ops->is_active_iterate(se->opaque)) { 1169 continue; 1170 } 1171 /* 1172 * In the postcopy phase, any device that doesn't know how to 1173 * do postcopy should have saved it's state in the _complete 1174 * call that's already run, it might get confused if we call 1175 * iterate afterwards. 1176 */ 1177 if (postcopy && 1178 !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) { 1179 continue; 1180 } 1181 if (qemu_file_rate_limit(f)) { 1182 return 0; 1183 } 1184 trace_savevm_section_start(se->idstr, se->section_id); 1185 1186 save_section_header(f, se, QEMU_VM_SECTION_PART); 1187 1188 ret = se->ops->save_live_iterate(f, se->opaque); 1189 trace_savevm_section_end(se->idstr, se->section_id, ret); 1190 save_section_footer(f, se); 1191 1192 if (ret < 0) { 1193 qemu_file_set_error(f, ret); 1194 } 1195 if (ret <= 0) { 1196 /* Do not proceed to the next vmstate before this one reported 1197 completion of the current stage. This serializes the migration 1198 and reduces the probability that a faster changing state is 1199 synchronized over and over again. */ 1200 break; 1201 } 1202 } 1203 return ret; 1204 } 1205 1206 static bool should_send_vmdesc(void) 1207 { 1208 MachineState *machine = MACHINE(qdev_get_machine()); 1209 bool in_postcopy = migration_in_postcopy(); 1210 return !machine->suppress_vmdesc && !in_postcopy; 1211 } 1212 1213 /* 1214 * Calls the save_live_complete_postcopy methods 1215 * causing the last few pages to be sent immediately and doing any associated 1216 * cleanup. 1217 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete 1218 * all the other devices, but that happens at the point we switch to postcopy. 1219 */ 1220 void qemu_savevm_state_complete_postcopy(QEMUFile *f) 1221 { 1222 SaveStateEntry *se; 1223 int ret; 1224 1225 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1226 if (!se->ops || !se->ops->save_live_complete_postcopy) { 1227 continue; 1228 } 1229 if (se->ops && se->ops->is_active) { 1230 if (!se->ops->is_active(se->opaque)) { 1231 continue; 1232 } 1233 } 1234 trace_savevm_section_start(se->idstr, se->section_id); 1235 /* Section type */ 1236 qemu_put_byte(f, QEMU_VM_SECTION_END); 1237 qemu_put_be32(f, se->section_id); 1238 1239 ret = se->ops->save_live_complete_postcopy(f, se->opaque); 1240 trace_savevm_section_end(se->idstr, se->section_id, ret); 1241 save_section_footer(f, se); 1242 if (ret < 0) { 1243 qemu_file_set_error(f, ret); 1244 return; 1245 } 1246 } 1247 1248 qemu_put_byte(f, QEMU_VM_EOF); 1249 qemu_fflush(f); 1250 } 1251 1252 int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only, 1253 bool inactivate_disks) 1254 { 1255 QJSON *vmdesc; 1256 int vmdesc_len; 1257 SaveStateEntry *se; 1258 int ret; 1259 bool in_postcopy = migration_in_postcopy(); 1260 Error *local_err = NULL; 1261 1262 if (precopy_notify(PRECOPY_NOTIFY_COMPLETE, &local_err)) { 1263 error_report_err(local_err); 1264 } 1265 1266 trace_savevm_state_complete_precopy(); 1267 1268 cpu_synchronize_all_states(); 1269 1270 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1271 if (!se->ops || 1272 (in_postcopy && se->ops->has_postcopy && 1273 se->ops->has_postcopy(se->opaque)) || 1274 (in_postcopy && !iterable_only) || 1275 !se->ops->save_live_complete_precopy) { 1276 continue; 1277 } 1278 1279 if (se->ops && se->ops->is_active) { 1280 if (!se->ops->is_active(se->opaque)) { 1281 continue; 1282 } 1283 } 1284 trace_savevm_section_start(se->idstr, se->section_id); 1285 1286 save_section_header(f, se, QEMU_VM_SECTION_END); 1287 1288 ret = se->ops->save_live_complete_precopy(f, se->opaque); 1289 trace_savevm_section_end(se->idstr, se->section_id, ret); 1290 save_section_footer(f, se); 1291 if (ret < 0) { 1292 qemu_file_set_error(f, ret); 1293 return -1; 1294 } 1295 } 1296 1297 if (iterable_only) { 1298 return 0; 1299 } 1300 1301 vmdesc = qjson_new(); 1302 json_prop_int(vmdesc, "page_size", qemu_target_page_size()); 1303 json_start_array(vmdesc, "devices"); 1304 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1305 1306 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1307 continue; 1308 } 1309 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1310 trace_savevm_section_skip(se->idstr, se->section_id); 1311 continue; 1312 } 1313 1314 trace_savevm_section_start(se->idstr, se->section_id); 1315 1316 json_start_object(vmdesc, NULL); 1317 json_prop_str(vmdesc, "name", se->idstr); 1318 json_prop_int(vmdesc, "instance_id", se->instance_id); 1319 1320 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1321 ret = vmstate_save(f, se, vmdesc); 1322 if (ret) { 1323 qemu_file_set_error(f, ret); 1324 return ret; 1325 } 1326 trace_savevm_section_end(se->idstr, se->section_id, 0); 1327 save_section_footer(f, se); 1328 1329 json_end_object(vmdesc); 1330 } 1331 1332 if (inactivate_disks) { 1333 /* Inactivate before sending QEMU_VM_EOF so that the 1334 * bdrv_invalidate_cache_all() on the other end won't fail. */ 1335 ret = bdrv_inactivate_all(); 1336 if (ret) { 1337 error_report("%s: bdrv_inactivate_all() failed (%d)", 1338 __func__, ret); 1339 qemu_file_set_error(f, ret); 1340 return ret; 1341 } 1342 } 1343 if (!in_postcopy) { 1344 /* Postcopy stream will still be going */ 1345 qemu_put_byte(f, QEMU_VM_EOF); 1346 } 1347 1348 json_end_array(vmdesc); 1349 qjson_finish(vmdesc); 1350 vmdesc_len = strlen(qjson_get_str(vmdesc)); 1351 1352 if (should_send_vmdesc()) { 1353 qemu_put_byte(f, QEMU_VM_VMDESCRIPTION); 1354 qemu_put_be32(f, vmdesc_len); 1355 qemu_put_buffer(f, (uint8_t *)qjson_get_str(vmdesc), vmdesc_len); 1356 } 1357 qjson_destroy(vmdesc); 1358 1359 qemu_fflush(f); 1360 return 0; 1361 } 1362 1363 /* Give an estimate of the amount left to be transferred, 1364 * the result is split into the amount for units that can and 1365 * for units that can't do postcopy. 1366 */ 1367 void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size, 1368 uint64_t *res_precopy_only, 1369 uint64_t *res_compatible, 1370 uint64_t *res_postcopy_only) 1371 { 1372 SaveStateEntry *se; 1373 1374 *res_precopy_only = 0; 1375 *res_compatible = 0; 1376 *res_postcopy_only = 0; 1377 1378 1379 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1380 if (!se->ops || !se->ops->save_live_pending) { 1381 continue; 1382 } 1383 if (se->ops && se->ops->is_active) { 1384 if (!se->ops->is_active(se->opaque)) { 1385 continue; 1386 } 1387 } 1388 se->ops->save_live_pending(f, se->opaque, threshold_size, 1389 res_precopy_only, res_compatible, 1390 res_postcopy_only); 1391 } 1392 } 1393 1394 void qemu_savevm_state_cleanup(void) 1395 { 1396 SaveStateEntry *se; 1397 Error *local_err = NULL; 1398 1399 if (precopy_notify(PRECOPY_NOTIFY_CLEANUP, &local_err)) { 1400 error_report_err(local_err); 1401 } 1402 1403 trace_savevm_state_cleanup(); 1404 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1405 if (se->ops && se->ops->save_cleanup) { 1406 se->ops->save_cleanup(se->opaque); 1407 } 1408 } 1409 } 1410 1411 static int qemu_savevm_state(QEMUFile *f, Error **errp) 1412 { 1413 int ret; 1414 MigrationState *ms = migrate_get_current(); 1415 MigrationStatus status; 1416 1417 if (migration_is_setup_or_active(ms->state) || 1418 ms->state == MIGRATION_STATUS_CANCELLING || 1419 ms->state == MIGRATION_STATUS_COLO) { 1420 error_setg(errp, QERR_MIGRATION_ACTIVE); 1421 return -EINVAL; 1422 } 1423 1424 if (migrate_use_block()) { 1425 error_setg(errp, "Block migration and snapshots are incompatible"); 1426 return -EINVAL; 1427 } 1428 1429 migrate_init(ms); 1430 ms->to_dst_file = f; 1431 1432 qemu_mutex_unlock_iothread(); 1433 qemu_savevm_state_header(f); 1434 qemu_savevm_state_setup(f); 1435 qemu_mutex_lock_iothread(); 1436 1437 while (qemu_file_get_error(f) == 0) { 1438 if (qemu_savevm_state_iterate(f, false) > 0) { 1439 break; 1440 } 1441 } 1442 1443 ret = qemu_file_get_error(f); 1444 if (ret == 0) { 1445 qemu_savevm_state_complete_precopy(f, false, false); 1446 ret = qemu_file_get_error(f); 1447 } 1448 qemu_savevm_state_cleanup(); 1449 if (ret != 0) { 1450 error_setg_errno(errp, -ret, "Error while writing VM state"); 1451 } 1452 1453 if (ret != 0) { 1454 status = MIGRATION_STATUS_FAILED; 1455 } else { 1456 status = MIGRATION_STATUS_COMPLETED; 1457 } 1458 migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status); 1459 1460 /* f is outer parameter, it should not stay in global migration state after 1461 * this function finished */ 1462 ms->to_dst_file = NULL; 1463 1464 return ret; 1465 } 1466 1467 void qemu_savevm_live_state(QEMUFile *f) 1468 { 1469 /* save QEMU_VM_SECTION_END section */ 1470 qemu_savevm_state_complete_precopy(f, true, false); 1471 qemu_put_byte(f, QEMU_VM_EOF); 1472 } 1473 1474 int qemu_save_device_state(QEMUFile *f) 1475 { 1476 SaveStateEntry *se; 1477 1478 if (!migration_in_colo_state()) { 1479 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1480 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1481 } 1482 cpu_synchronize_all_states(); 1483 1484 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1485 int ret; 1486 1487 if (se->is_ram) { 1488 continue; 1489 } 1490 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1491 continue; 1492 } 1493 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1494 continue; 1495 } 1496 1497 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1498 1499 ret = vmstate_save(f, se, NULL); 1500 if (ret) { 1501 return ret; 1502 } 1503 1504 save_section_footer(f, se); 1505 } 1506 1507 qemu_put_byte(f, QEMU_VM_EOF); 1508 1509 return qemu_file_get_error(f); 1510 } 1511 1512 static SaveStateEntry *find_se(const char *idstr, int instance_id) 1513 { 1514 SaveStateEntry *se; 1515 1516 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1517 if (!strcmp(se->idstr, idstr) && 1518 (instance_id == se->instance_id || 1519 instance_id == se->alias_id)) 1520 return se; 1521 /* Migrating from an older version? */ 1522 if (strstr(se->idstr, idstr) && se->compat) { 1523 if (!strcmp(se->compat->idstr, idstr) && 1524 (instance_id == se->compat->instance_id || 1525 instance_id == se->alias_id)) 1526 return se; 1527 } 1528 } 1529 return NULL; 1530 } 1531 1532 enum LoadVMExitCodes { 1533 /* Allow a command to quit all layers of nested loadvm loops */ 1534 LOADVM_QUIT = 1, 1535 }; 1536 1537 /* ------ incoming postcopy messages ------ */ 1538 /* 'advise' arrives before any transfers just to tell us that a postcopy 1539 * *might* happen - it might be skipped if precopy transferred everything 1540 * quickly. 1541 */ 1542 static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis, 1543 uint16_t len) 1544 { 1545 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1546 uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps; 1547 Error *local_err = NULL; 1548 1549 trace_loadvm_postcopy_handle_advise(); 1550 if (ps != POSTCOPY_INCOMING_NONE) { 1551 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps); 1552 return -1; 1553 } 1554 1555 switch (len) { 1556 case 0: 1557 if (migrate_postcopy_ram()) { 1558 error_report("RAM postcopy is enabled but have 0 byte advise"); 1559 return -EINVAL; 1560 } 1561 return 0; 1562 case 8 + 8: 1563 if (!migrate_postcopy_ram()) { 1564 error_report("RAM postcopy is disabled but have 16 byte advise"); 1565 return -EINVAL; 1566 } 1567 break; 1568 default: 1569 error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len); 1570 return -EINVAL; 1571 } 1572 1573 if (!postcopy_ram_supported_by_host(mis)) { 1574 postcopy_state_set(POSTCOPY_INCOMING_NONE); 1575 return -1; 1576 } 1577 1578 remote_pagesize_summary = qemu_get_be64(mis->from_src_file); 1579 local_pagesize_summary = ram_pagesize_summary(); 1580 1581 if (remote_pagesize_summary != local_pagesize_summary) { 1582 /* 1583 * This detects two potential causes of mismatch: 1584 * a) A mismatch in host page sizes 1585 * Some combinations of mismatch are probably possible but it gets 1586 * a bit more complicated. In particular we need to place whole 1587 * host pages on the dest at once, and we need to ensure that we 1588 * handle dirtying to make sure we never end up sending part of 1589 * a hostpage on it's own. 1590 * b) The use of different huge page sizes on source/destination 1591 * a more fine grain test is performed during RAM block migration 1592 * but this test here causes a nice early clear failure, and 1593 * also fails when passed to an older qemu that doesn't 1594 * do huge pages. 1595 */ 1596 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64 1597 " d=%" PRIx64 ")", 1598 remote_pagesize_summary, local_pagesize_summary); 1599 return -1; 1600 } 1601 1602 remote_tps = qemu_get_be64(mis->from_src_file); 1603 if (remote_tps != qemu_target_page_size()) { 1604 /* 1605 * Again, some differences could be dealt with, but for now keep it 1606 * simple. 1607 */ 1608 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)", 1609 (int)remote_tps, qemu_target_page_size()); 1610 return -1; 1611 } 1612 1613 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) { 1614 error_report_err(local_err); 1615 return -1; 1616 } 1617 1618 if (ram_postcopy_incoming_init(mis)) { 1619 return -1; 1620 } 1621 1622 postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1623 1624 return 0; 1625 } 1626 1627 /* After postcopy we will be told to throw some pages away since they're 1628 * dirty and will have to be demand fetched. Must happen before CPU is 1629 * started. 1630 * There can be 0..many of these messages, each encoding multiple pages. 1631 */ 1632 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis, 1633 uint16_t len) 1634 { 1635 int tmp; 1636 char ramid[256]; 1637 PostcopyState ps = postcopy_state_get(); 1638 1639 trace_loadvm_postcopy_ram_handle_discard(); 1640 1641 switch (ps) { 1642 case POSTCOPY_INCOMING_ADVISE: 1643 /* 1st discard */ 1644 tmp = postcopy_ram_prepare_discard(mis); 1645 if (tmp) { 1646 return tmp; 1647 } 1648 break; 1649 1650 case POSTCOPY_INCOMING_DISCARD: 1651 /* Expected state */ 1652 break; 1653 1654 default: 1655 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)", 1656 ps); 1657 return -1; 1658 } 1659 /* We're expecting a 1660 * Version (0) 1661 * a RAM ID string (length byte, name, 0 term) 1662 * then at least 1 16 byte chunk 1663 */ 1664 if (len < (1 + 1 + 1 + 1 + 2 * 8)) { 1665 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1666 return -1; 1667 } 1668 1669 tmp = qemu_get_byte(mis->from_src_file); 1670 if (tmp != postcopy_ram_discard_version) { 1671 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp); 1672 return -1; 1673 } 1674 1675 if (!qemu_get_counted_string(mis->from_src_file, ramid)) { 1676 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID"); 1677 return -1; 1678 } 1679 tmp = qemu_get_byte(mis->from_src_file); 1680 if (tmp != 0) { 1681 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp); 1682 return -1; 1683 } 1684 1685 len -= 3 + strlen(ramid); 1686 if (len % 16) { 1687 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1688 return -1; 1689 } 1690 trace_loadvm_postcopy_ram_handle_discard_header(ramid, len); 1691 while (len) { 1692 uint64_t start_addr, block_length; 1693 start_addr = qemu_get_be64(mis->from_src_file); 1694 block_length = qemu_get_be64(mis->from_src_file); 1695 1696 len -= 16; 1697 int ret = ram_discard_range(ramid, start_addr, block_length); 1698 if (ret) { 1699 return ret; 1700 } 1701 } 1702 trace_loadvm_postcopy_ram_handle_discard_end(); 1703 1704 return 0; 1705 } 1706 1707 /* 1708 * Triggered by a postcopy_listen command; this thread takes over reading 1709 * the input stream, leaving the main thread free to carry on loading the rest 1710 * of the device state (from RAM). 1711 * (TODO:This could do with being in a postcopy file - but there again it's 1712 * just another input loop, not that postcopy specific) 1713 */ 1714 static void *postcopy_ram_listen_thread(void *opaque) 1715 { 1716 MigrationIncomingState *mis = migration_incoming_get_current(); 1717 QEMUFile *f = mis->from_src_file; 1718 int load_res; 1719 1720 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 1721 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1722 qemu_sem_post(&mis->listen_thread_sem); 1723 trace_postcopy_ram_listen_thread_start(); 1724 1725 rcu_register_thread(); 1726 /* 1727 * Because we're a thread and not a coroutine we can't yield 1728 * in qemu_file, and thus we must be blocking now. 1729 */ 1730 qemu_file_set_blocking(f, true); 1731 load_res = qemu_loadvm_state_main(f, mis); 1732 1733 /* 1734 * This is tricky, but, mis->from_src_file can change after it 1735 * returns, when postcopy recovery happened. In the future, we may 1736 * want a wrapper for the QEMUFile handle. 1737 */ 1738 f = mis->from_src_file; 1739 1740 /* And non-blocking again so we don't block in any cleanup */ 1741 qemu_file_set_blocking(f, false); 1742 1743 trace_postcopy_ram_listen_thread_exit(); 1744 if (load_res < 0) { 1745 error_report("%s: loadvm failed: %d", __func__, load_res); 1746 qemu_file_set_error(f, load_res); 1747 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1748 MIGRATION_STATUS_FAILED); 1749 } else { 1750 /* 1751 * This looks good, but it's possible that the device loading in the 1752 * main thread hasn't finished yet, and so we might not be in 'RUN' 1753 * state yet; wait for the end of the main thread. 1754 */ 1755 qemu_event_wait(&mis->main_thread_load_event); 1756 } 1757 postcopy_ram_incoming_cleanup(mis); 1758 1759 if (load_res < 0) { 1760 /* 1761 * If something went wrong then we have a bad state so exit; 1762 * depending how far we got it might be possible at this point 1763 * to leave the guest running and fire MCEs for pages that never 1764 * arrived as a desperate recovery step. 1765 */ 1766 rcu_unregister_thread(); 1767 exit(EXIT_FAILURE); 1768 } 1769 1770 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1771 MIGRATION_STATUS_COMPLETED); 1772 /* 1773 * If everything has worked fine, then the main thread has waited 1774 * for us to start, and we're the last use of the mis. 1775 * (If something broke then qemu will have to exit anyway since it's 1776 * got a bad migration state). 1777 */ 1778 migration_incoming_state_destroy(); 1779 qemu_loadvm_state_cleanup(); 1780 1781 rcu_unregister_thread(); 1782 mis->have_listen_thread = false; 1783 return NULL; 1784 } 1785 1786 /* After this message we must be able to immediately receive postcopy data */ 1787 static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) 1788 { 1789 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING); 1790 trace_loadvm_postcopy_handle_listen(); 1791 Error *local_err = NULL; 1792 1793 if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) { 1794 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps); 1795 return -1; 1796 } 1797 if (ps == POSTCOPY_INCOMING_ADVISE) { 1798 /* 1799 * A rare case, we entered listen without having to do any discards, 1800 * so do the setup that's normally done at the time of the 1st discard. 1801 */ 1802 if (migrate_postcopy_ram()) { 1803 postcopy_ram_prepare_discard(mis); 1804 } 1805 } 1806 1807 /* 1808 * Sensitise RAM - can now generate requests for blocks that don't exist 1809 * However, at this point the CPU shouldn't be running, and the IO 1810 * shouldn't be doing anything yet so don't actually expect requests 1811 */ 1812 if (migrate_postcopy_ram()) { 1813 if (postcopy_ram_enable_notify(mis)) { 1814 postcopy_ram_incoming_cleanup(mis); 1815 return -1; 1816 } 1817 } 1818 1819 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) { 1820 error_report_err(local_err); 1821 return -1; 1822 } 1823 1824 if (mis->have_listen_thread) { 1825 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread"); 1826 return -1; 1827 } 1828 1829 mis->have_listen_thread = true; 1830 /* Start up the listening thread and wait for it to signal ready */ 1831 qemu_sem_init(&mis->listen_thread_sem, 0); 1832 qemu_thread_create(&mis->listen_thread, "postcopy/listen", 1833 postcopy_ram_listen_thread, NULL, 1834 QEMU_THREAD_DETACHED); 1835 qemu_sem_wait(&mis->listen_thread_sem); 1836 qemu_sem_destroy(&mis->listen_thread_sem); 1837 1838 return 0; 1839 } 1840 1841 1842 typedef struct { 1843 QEMUBH *bh; 1844 } HandleRunBhData; 1845 1846 static void loadvm_postcopy_handle_run_bh(void *opaque) 1847 { 1848 Error *local_err = NULL; 1849 HandleRunBhData *data = opaque; 1850 MigrationIncomingState *mis = migration_incoming_get_current(); 1851 1852 /* TODO we should move all of this lot into postcopy_ram.c or a shared code 1853 * in migration.c 1854 */ 1855 cpu_synchronize_all_post_init(); 1856 1857 qemu_announce_self(&mis->announce_timer, migrate_announce_params()); 1858 1859 /* Make sure all file formats flush their mutable metadata. 1860 * If we get an error here, just don't restart the VM yet. */ 1861 bdrv_invalidate_cache_all(&local_err); 1862 if (local_err) { 1863 error_report_err(local_err); 1864 local_err = NULL; 1865 autostart = false; 1866 } 1867 1868 trace_loadvm_postcopy_handle_run_cpu_sync(); 1869 1870 trace_loadvm_postcopy_handle_run_vmstart(); 1871 1872 dirty_bitmap_mig_before_vm_start(); 1873 1874 if (autostart) { 1875 /* Hold onto your hats, starting the CPU */ 1876 vm_start(); 1877 } else { 1878 /* leave it paused and let management decide when to start the CPU */ 1879 runstate_set(RUN_STATE_PAUSED); 1880 } 1881 1882 qemu_bh_delete(data->bh); 1883 g_free(data); 1884 } 1885 1886 /* After all discards we can start running and asking for pages */ 1887 static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) 1888 { 1889 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING); 1890 HandleRunBhData *data; 1891 1892 trace_loadvm_postcopy_handle_run(); 1893 if (ps != POSTCOPY_INCOMING_LISTENING) { 1894 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps); 1895 return -1; 1896 } 1897 1898 data = g_new(HandleRunBhData, 1); 1899 data->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, data); 1900 qemu_bh_schedule(data->bh); 1901 1902 /* We need to finish reading the stream from the package 1903 * and also stop reading anything more from the stream that loaded the 1904 * package (since it's now being read by the listener thread). 1905 * LOADVM_QUIT will quit all the layers of nested loadvm loops. 1906 */ 1907 return LOADVM_QUIT; 1908 } 1909 1910 static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis) 1911 { 1912 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) { 1913 error_report("%s: illegal resume received", __func__); 1914 /* Don't fail the load, only for this. */ 1915 return 0; 1916 } 1917 1918 /* 1919 * This means source VM is ready to resume the postcopy migration. 1920 * It's time to switch state and release the fault thread to 1921 * continue service page faults. 1922 */ 1923 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER, 1924 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1925 qemu_sem_post(&mis->postcopy_pause_sem_fault); 1926 1927 trace_loadvm_postcopy_handle_resume(); 1928 1929 /* Tell source that "we are ready" */ 1930 migrate_send_rp_resume_ack(mis, MIGRATION_RESUME_ACK_VALUE); 1931 1932 return 0; 1933 } 1934 1935 /** 1936 * Immediately following this command is a blob of data containing an embedded 1937 * chunk of migration stream; read it and load it. 1938 * 1939 * @mis: Incoming state 1940 * @length: Length of packaged data to read 1941 * 1942 * Returns: Negative values on error 1943 * 1944 */ 1945 static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis) 1946 { 1947 int ret; 1948 size_t length; 1949 QIOChannelBuffer *bioc; 1950 1951 length = qemu_get_be32(mis->from_src_file); 1952 trace_loadvm_handle_cmd_packaged(length); 1953 1954 if (length > MAX_VM_CMD_PACKAGED_SIZE) { 1955 error_report("Unreasonably large packaged state: %zu", length); 1956 return -1; 1957 } 1958 1959 bioc = qio_channel_buffer_new(length); 1960 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-loadvm-buffer"); 1961 ret = qemu_get_buffer(mis->from_src_file, 1962 bioc->data, 1963 length); 1964 if (ret != length) { 1965 object_unref(OBJECT(bioc)); 1966 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu", 1967 ret, length); 1968 return (ret < 0) ? ret : -EAGAIN; 1969 } 1970 bioc->usage += length; 1971 trace_loadvm_handle_cmd_packaged_received(ret); 1972 1973 QEMUFile *packf = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); 1974 1975 ret = qemu_loadvm_state_main(packf, mis); 1976 trace_loadvm_handle_cmd_packaged_main(ret); 1977 qemu_fclose(packf); 1978 object_unref(OBJECT(bioc)); 1979 1980 return ret; 1981 } 1982 1983 /* 1984 * Handle request that source requests for recved_bitmap on 1985 * destination. Payload format: 1986 * 1987 * len (1 byte) + ramblock_name (<255 bytes) 1988 */ 1989 static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis, 1990 uint16_t len) 1991 { 1992 QEMUFile *file = mis->from_src_file; 1993 RAMBlock *rb; 1994 char block_name[256]; 1995 size_t cnt; 1996 1997 cnt = qemu_get_counted_string(file, block_name); 1998 if (!cnt) { 1999 error_report("%s: failed to read block name", __func__); 2000 return -EINVAL; 2001 } 2002 2003 /* Validate before using the data */ 2004 if (qemu_file_get_error(file)) { 2005 return qemu_file_get_error(file); 2006 } 2007 2008 if (len != cnt + 1) { 2009 error_report("%s: invalid payload length (%d)", __func__, len); 2010 return -EINVAL; 2011 } 2012 2013 rb = qemu_ram_block_by_name(block_name); 2014 if (!rb) { 2015 error_report("%s: block '%s' not found", __func__, block_name); 2016 return -EINVAL; 2017 } 2018 2019 migrate_send_rp_recv_bitmap(mis, block_name); 2020 2021 trace_loadvm_handle_recv_bitmap(block_name); 2022 2023 return 0; 2024 } 2025 2026 static int loadvm_process_enable_colo(MigrationIncomingState *mis) 2027 { 2028 migration_incoming_enable_colo(); 2029 return colo_init_ram_cache(); 2030 } 2031 2032 /* 2033 * Process an incoming 'QEMU_VM_COMMAND' 2034 * 0 just a normal return 2035 * LOADVM_QUIT All good, but exit the loop 2036 * <0 Error 2037 */ 2038 static int loadvm_process_command(QEMUFile *f) 2039 { 2040 MigrationIncomingState *mis = migration_incoming_get_current(); 2041 uint16_t cmd; 2042 uint16_t len; 2043 uint32_t tmp32; 2044 2045 cmd = qemu_get_be16(f); 2046 len = qemu_get_be16(f); 2047 2048 /* Check validity before continue processing of cmds */ 2049 if (qemu_file_get_error(f)) { 2050 return qemu_file_get_error(f); 2051 } 2052 2053 trace_loadvm_process_command(cmd, len); 2054 if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) { 2055 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len); 2056 return -EINVAL; 2057 } 2058 2059 if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) { 2060 error_report("%s received with bad length - expecting %zu, got %d", 2061 mig_cmd_args[cmd].name, 2062 (size_t)mig_cmd_args[cmd].len, len); 2063 return -ERANGE; 2064 } 2065 2066 switch (cmd) { 2067 case MIG_CMD_OPEN_RETURN_PATH: 2068 if (mis->to_src_file) { 2069 error_report("CMD_OPEN_RETURN_PATH called when RP already open"); 2070 /* Not really a problem, so don't give up */ 2071 return 0; 2072 } 2073 mis->to_src_file = qemu_file_get_return_path(f); 2074 if (!mis->to_src_file) { 2075 error_report("CMD_OPEN_RETURN_PATH failed"); 2076 return -1; 2077 } 2078 break; 2079 2080 case MIG_CMD_PING: 2081 tmp32 = qemu_get_be32(f); 2082 trace_loadvm_process_command_ping(tmp32); 2083 if (!mis->to_src_file) { 2084 error_report("CMD_PING (0x%x) received with no return path", 2085 tmp32); 2086 return -1; 2087 } 2088 migrate_send_rp_pong(mis, tmp32); 2089 break; 2090 2091 case MIG_CMD_PACKAGED: 2092 return loadvm_handle_cmd_packaged(mis); 2093 2094 case MIG_CMD_POSTCOPY_ADVISE: 2095 return loadvm_postcopy_handle_advise(mis, len); 2096 2097 case MIG_CMD_POSTCOPY_LISTEN: 2098 return loadvm_postcopy_handle_listen(mis); 2099 2100 case MIG_CMD_POSTCOPY_RUN: 2101 return loadvm_postcopy_handle_run(mis); 2102 2103 case MIG_CMD_POSTCOPY_RAM_DISCARD: 2104 return loadvm_postcopy_ram_handle_discard(mis, len); 2105 2106 case MIG_CMD_POSTCOPY_RESUME: 2107 return loadvm_postcopy_handle_resume(mis); 2108 2109 case MIG_CMD_RECV_BITMAP: 2110 return loadvm_handle_recv_bitmap(mis, len); 2111 2112 case MIG_CMD_ENABLE_COLO: 2113 return loadvm_process_enable_colo(mis); 2114 } 2115 2116 return 0; 2117 } 2118 2119 /* 2120 * Read a footer off the wire and check that it matches the expected section 2121 * 2122 * Returns: true if the footer was good 2123 * false if there is a problem (and calls error_report to say why) 2124 */ 2125 static bool check_section_footer(QEMUFile *f, SaveStateEntry *se) 2126 { 2127 int ret; 2128 uint8_t read_mark; 2129 uint32_t read_section_id; 2130 2131 if (!migrate_get_current()->send_section_footer) { 2132 /* No footer to check */ 2133 return true; 2134 } 2135 2136 read_mark = qemu_get_byte(f); 2137 2138 ret = qemu_file_get_error(f); 2139 if (ret) { 2140 error_report("%s: Read section footer failed: %d", 2141 __func__, ret); 2142 return false; 2143 } 2144 2145 if (read_mark != QEMU_VM_SECTION_FOOTER) { 2146 error_report("Missing section footer for %s", se->idstr); 2147 return false; 2148 } 2149 2150 read_section_id = qemu_get_be32(f); 2151 if (read_section_id != se->load_section_id) { 2152 error_report("Mismatched section id in footer for %s -" 2153 " read 0x%x expected 0x%x", 2154 se->idstr, read_section_id, se->load_section_id); 2155 return false; 2156 } 2157 2158 /* All good */ 2159 return true; 2160 } 2161 2162 static int 2163 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis) 2164 { 2165 uint32_t instance_id, version_id, section_id; 2166 SaveStateEntry *se; 2167 char idstr[256]; 2168 int ret; 2169 2170 /* Read section start */ 2171 section_id = qemu_get_be32(f); 2172 if (!qemu_get_counted_string(f, idstr)) { 2173 error_report("Unable to read ID string for section %u", 2174 section_id); 2175 return -EINVAL; 2176 } 2177 instance_id = qemu_get_be32(f); 2178 version_id = qemu_get_be32(f); 2179 2180 ret = qemu_file_get_error(f); 2181 if (ret) { 2182 error_report("%s: Failed to read instance/version ID: %d", 2183 __func__, ret); 2184 return ret; 2185 } 2186 2187 trace_qemu_loadvm_state_section_startfull(section_id, idstr, 2188 instance_id, version_id); 2189 /* Find savevm section */ 2190 se = find_se(idstr, instance_id); 2191 if (se == NULL) { 2192 error_report("Unknown savevm section or instance '%s' %d. " 2193 "Make sure that your current VM setup matches your " 2194 "saved VM setup, including any hotplugged devices", 2195 idstr, instance_id); 2196 return -EINVAL; 2197 } 2198 2199 /* Validate version */ 2200 if (version_id > se->version_id) { 2201 error_report("savevm: unsupported version %d for '%s' v%d", 2202 version_id, idstr, se->version_id); 2203 return -EINVAL; 2204 } 2205 se->load_version_id = version_id; 2206 se->load_section_id = section_id; 2207 2208 /* Validate if it is a device's state */ 2209 if (xen_enabled() && se->is_ram) { 2210 error_report("loadvm: %s RAM loading not allowed on Xen", idstr); 2211 return -EINVAL; 2212 } 2213 2214 ret = vmstate_load(f, se); 2215 if (ret < 0) { 2216 error_report("error while loading state for instance 0x%x of" 2217 " device '%s'", instance_id, idstr); 2218 return ret; 2219 } 2220 if (!check_section_footer(f, se)) { 2221 return -EINVAL; 2222 } 2223 2224 return 0; 2225 } 2226 2227 static int 2228 qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis) 2229 { 2230 uint32_t section_id; 2231 SaveStateEntry *se; 2232 int ret; 2233 2234 section_id = qemu_get_be32(f); 2235 2236 ret = qemu_file_get_error(f); 2237 if (ret) { 2238 error_report("%s: Failed to read section ID: %d", 2239 __func__, ret); 2240 return ret; 2241 } 2242 2243 trace_qemu_loadvm_state_section_partend(section_id); 2244 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2245 if (se->load_section_id == section_id) { 2246 break; 2247 } 2248 } 2249 if (se == NULL) { 2250 error_report("Unknown savevm section %d", section_id); 2251 return -EINVAL; 2252 } 2253 2254 ret = vmstate_load(f, se); 2255 if (ret < 0) { 2256 error_report("error while loading state section id %d(%s)", 2257 section_id, se->idstr); 2258 return ret; 2259 } 2260 if (!check_section_footer(f, se)) { 2261 return -EINVAL; 2262 } 2263 2264 return 0; 2265 } 2266 2267 static int qemu_loadvm_state_header(QEMUFile *f) 2268 { 2269 unsigned int v; 2270 int ret; 2271 2272 v = qemu_get_be32(f); 2273 if (v != QEMU_VM_FILE_MAGIC) { 2274 error_report("Not a migration stream"); 2275 return -EINVAL; 2276 } 2277 2278 v = qemu_get_be32(f); 2279 if (v == QEMU_VM_FILE_VERSION_COMPAT) { 2280 error_report("SaveVM v2 format is obsolete and don't work anymore"); 2281 return -ENOTSUP; 2282 } 2283 if (v != QEMU_VM_FILE_VERSION) { 2284 error_report("Unsupported migration stream version"); 2285 return -ENOTSUP; 2286 } 2287 2288 if (migrate_get_current()->send_configuration) { 2289 if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) { 2290 error_report("Configuration section missing"); 2291 qemu_loadvm_state_cleanup(); 2292 return -EINVAL; 2293 } 2294 ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0); 2295 2296 if (ret) { 2297 qemu_loadvm_state_cleanup(); 2298 return ret; 2299 } 2300 } 2301 return 0; 2302 } 2303 2304 static int qemu_loadvm_state_setup(QEMUFile *f) 2305 { 2306 SaveStateEntry *se; 2307 int ret; 2308 2309 trace_loadvm_state_setup(); 2310 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2311 if (!se->ops || !se->ops->load_setup) { 2312 continue; 2313 } 2314 if (se->ops && se->ops->is_active) { 2315 if (!se->ops->is_active(se->opaque)) { 2316 continue; 2317 } 2318 } 2319 2320 ret = se->ops->load_setup(f, se->opaque); 2321 if (ret < 0) { 2322 qemu_file_set_error(f, ret); 2323 error_report("Load state of device %s failed", se->idstr); 2324 return ret; 2325 } 2326 } 2327 return 0; 2328 } 2329 2330 void qemu_loadvm_state_cleanup(void) 2331 { 2332 SaveStateEntry *se; 2333 2334 trace_loadvm_state_cleanup(); 2335 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2336 if (se->ops && se->ops->load_cleanup) { 2337 se->ops->load_cleanup(se->opaque); 2338 } 2339 } 2340 } 2341 2342 /* Return true if we should continue the migration, or false. */ 2343 static bool postcopy_pause_incoming(MigrationIncomingState *mis) 2344 { 2345 trace_postcopy_pause_incoming(); 2346 2347 /* Clear the triggered bit to allow one recovery */ 2348 mis->postcopy_recover_triggered = false; 2349 2350 assert(mis->from_src_file); 2351 qemu_file_shutdown(mis->from_src_file); 2352 qemu_fclose(mis->from_src_file); 2353 mis->from_src_file = NULL; 2354 2355 assert(mis->to_src_file); 2356 qemu_file_shutdown(mis->to_src_file); 2357 qemu_mutex_lock(&mis->rp_mutex); 2358 qemu_fclose(mis->to_src_file); 2359 mis->to_src_file = NULL; 2360 qemu_mutex_unlock(&mis->rp_mutex); 2361 2362 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2363 MIGRATION_STATUS_POSTCOPY_PAUSED); 2364 2365 /* Notify the fault thread for the invalidated file handle */ 2366 postcopy_fault_thread_notify(mis); 2367 2368 error_report("Detected IO failure for postcopy. " 2369 "Migration paused."); 2370 2371 while (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) { 2372 qemu_sem_wait(&mis->postcopy_pause_sem_dst); 2373 } 2374 2375 trace_postcopy_pause_incoming_continued(); 2376 2377 return true; 2378 } 2379 2380 int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis) 2381 { 2382 uint8_t section_type; 2383 int ret = 0; 2384 2385 retry: 2386 while (true) { 2387 section_type = qemu_get_byte(f); 2388 2389 if (qemu_file_get_error(f)) { 2390 ret = qemu_file_get_error(f); 2391 break; 2392 } 2393 2394 trace_qemu_loadvm_state_section(section_type); 2395 switch (section_type) { 2396 case QEMU_VM_SECTION_START: 2397 case QEMU_VM_SECTION_FULL: 2398 ret = qemu_loadvm_section_start_full(f, mis); 2399 if (ret < 0) { 2400 goto out; 2401 } 2402 break; 2403 case QEMU_VM_SECTION_PART: 2404 case QEMU_VM_SECTION_END: 2405 ret = qemu_loadvm_section_part_end(f, mis); 2406 if (ret < 0) { 2407 goto out; 2408 } 2409 break; 2410 case QEMU_VM_COMMAND: 2411 ret = loadvm_process_command(f); 2412 trace_qemu_loadvm_state_section_command(ret); 2413 if ((ret < 0) || (ret & LOADVM_QUIT)) { 2414 goto out; 2415 } 2416 break; 2417 case QEMU_VM_EOF: 2418 /* This is the end of migration */ 2419 goto out; 2420 default: 2421 error_report("Unknown savevm section type %d", section_type); 2422 ret = -EINVAL; 2423 goto out; 2424 } 2425 } 2426 2427 out: 2428 if (ret < 0) { 2429 qemu_file_set_error(f, ret); 2430 2431 /* 2432 * If we are during an active postcopy, then we pause instead 2433 * of bail out to at least keep the VM's dirty data. Note 2434 * that POSTCOPY_INCOMING_LISTENING stage is still not enough, 2435 * during which we're still receiving device states and we 2436 * still haven't yet started the VM on destination. 2437 */ 2438 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING && 2439 postcopy_pause_incoming(mis)) { 2440 /* Reset f to point to the newly created channel */ 2441 f = mis->from_src_file; 2442 goto retry; 2443 } 2444 } 2445 return ret; 2446 } 2447 2448 int qemu_loadvm_state(QEMUFile *f) 2449 { 2450 MigrationIncomingState *mis = migration_incoming_get_current(); 2451 Error *local_err = NULL; 2452 int ret; 2453 2454 if (qemu_savevm_state_blocked(&local_err)) { 2455 error_report_err(local_err); 2456 return -EINVAL; 2457 } 2458 2459 ret = qemu_loadvm_state_header(f); 2460 if (ret) { 2461 return ret; 2462 } 2463 2464 if (qemu_loadvm_state_setup(f) != 0) { 2465 return -EINVAL; 2466 } 2467 2468 cpu_synchronize_all_pre_loadvm(); 2469 2470 ret = qemu_loadvm_state_main(f, mis); 2471 qemu_event_set(&mis->main_thread_load_event); 2472 2473 trace_qemu_loadvm_state_post_main(ret); 2474 2475 if (mis->have_listen_thread) { 2476 /* Listen thread still going, can't clean up yet */ 2477 return ret; 2478 } 2479 2480 if (ret == 0) { 2481 ret = qemu_file_get_error(f); 2482 } 2483 2484 /* 2485 * Try to read in the VMDESC section as well, so that dumping tools that 2486 * intercept our migration stream have the chance to see it. 2487 */ 2488 2489 /* We've got to be careful; if we don't read the data and just shut the fd 2490 * then the sender can error if we close while it's still sending. 2491 * We also mustn't read data that isn't there; some transports (RDMA) 2492 * will stall waiting for that data when the source has already closed. 2493 */ 2494 if (ret == 0 && should_send_vmdesc()) { 2495 uint8_t *buf; 2496 uint32_t size; 2497 uint8_t section_type = qemu_get_byte(f); 2498 2499 if (section_type != QEMU_VM_VMDESCRIPTION) { 2500 error_report("Expected vmdescription section, but got %d", 2501 section_type); 2502 /* 2503 * It doesn't seem worth failing at this point since 2504 * we apparently have an otherwise valid VM state 2505 */ 2506 } else { 2507 buf = g_malloc(0x1000); 2508 size = qemu_get_be32(f); 2509 2510 while (size > 0) { 2511 uint32_t read_chunk = MIN(size, 0x1000); 2512 qemu_get_buffer(f, buf, read_chunk); 2513 size -= read_chunk; 2514 } 2515 g_free(buf); 2516 } 2517 } 2518 2519 qemu_loadvm_state_cleanup(); 2520 cpu_synchronize_all_post_init(); 2521 2522 return ret; 2523 } 2524 2525 int qemu_load_device_state(QEMUFile *f) 2526 { 2527 MigrationIncomingState *mis = migration_incoming_get_current(); 2528 int ret; 2529 2530 /* Load QEMU_VM_SECTION_FULL section */ 2531 ret = qemu_loadvm_state_main(f, mis); 2532 if (ret < 0) { 2533 error_report("Failed to load device state: %d", ret); 2534 return ret; 2535 } 2536 2537 cpu_synchronize_all_post_init(); 2538 return 0; 2539 } 2540 2541 int save_snapshot(const char *name, Error **errp) 2542 { 2543 BlockDriverState *bs, *bs1; 2544 QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1; 2545 int ret = -1; 2546 QEMUFile *f; 2547 int saved_vm_running; 2548 uint64_t vm_state_size; 2549 qemu_timeval tv; 2550 struct tm tm; 2551 AioContext *aio_context; 2552 2553 if (migration_is_blocked(errp)) { 2554 return ret; 2555 } 2556 2557 if (!replay_can_snapshot()) { 2558 error_setg(errp, "Record/replay does not allow making snapshot " 2559 "right now. Try once more later."); 2560 return ret; 2561 } 2562 2563 if (!bdrv_all_can_snapshot(&bs)) { 2564 error_setg(errp, "Device '%s' is writable but does not support " 2565 "snapshots", bdrv_get_device_name(bs)); 2566 return ret; 2567 } 2568 2569 /* Delete old snapshots of the same name */ 2570 if (name) { 2571 ret = bdrv_all_delete_snapshot(name, &bs1, errp); 2572 if (ret < 0) { 2573 error_prepend(errp, "Error while deleting snapshot on device " 2574 "'%s': ", bdrv_get_device_name(bs1)); 2575 return ret; 2576 } 2577 } 2578 2579 bs = bdrv_all_find_vmstate_bs(); 2580 if (bs == NULL) { 2581 error_setg(errp, "No block device can accept snapshots"); 2582 return ret; 2583 } 2584 aio_context = bdrv_get_aio_context(bs); 2585 2586 saved_vm_running = runstate_is_running(); 2587 2588 ret = global_state_store(); 2589 if (ret) { 2590 error_setg(errp, "Error saving global state"); 2591 return ret; 2592 } 2593 vm_stop(RUN_STATE_SAVE_VM); 2594 2595 bdrv_drain_all_begin(); 2596 2597 aio_context_acquire(aio_context); 2598 2599 memset(sn, 0, sizeof(*sn)); 2600 2601 /* fill auxiliary fields */ 2602 qemu_gettimeofday(&tv); 2603 sn->date_sec = tv.tv_sec; 2604 sn->date_nsec = tv.tv_usec * 1000; 2605 sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 2606 2607 if (name) { 2608 ret = bdrv_snapshot_find(bs, old_sn, name); 2609 if (ret >= 0) { 2610 pstrcpy(sn->name, sizeof(sn->name), old_sn->name); 2611 pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str); 2612 } else { 2613 pstrcpy(sn->name, sizeof(sn->name), name); 2614 } 2615 } else { 2616 /* cast below needed for OpenBSD where tv_sec is still 'long' */ 2617 localtime_r((const time_t *)&tv.tv_sec, &tm); 2618 strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm); 2619 } 2620 2621 /* save the VM state */ 2622 f = qemu_fopen_bdrv(bs, 1); 2623 if (!f) { 2624 error_setg(errp, "Could not open VM state file"); 2625 goto the_end; 2626 } 2627 ret = qemu_savevm_state(f, errp); 2628 vm_state_size = qemu_ftell(f); 2629 qemu_fclose(f); 2630 if (ret < 0) { 2631 goto the_end; 2632 } 2633 2634 /* The bdrv_all_create_snapshot() call that follows acquires the AioContext 2635 * for itself. BDRV_POLL_WHILE() does not support nested locking because 2636 * it only releases the lock once. Therefore synchronous I/O will deadlock 2637 * unless we release the AioContext before bdrv_all_create_snapshot(). 2638 */ 2639 aio_context_release(aio_context); 2640 aio_context = NULL; 2641 2642 ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs); 2643 if (ret < 0) { 2644 error_setg(errp, "Error while creating snapshot on '%s'", 2645 bdrv_get_device_name(bs)); 2646 goto the_end; 2647 } 2648 2649 ret = 0; 2650 2651 the_end: 2652 if (aio_context) { 2653 aio_context_release(aio_context); 2654 } 2655 2656 bdrv_drain_all_end(); 2657 2658 if (saved_vm_running) { 2659 vm_start(); 2660 } 2661 return ret; 2662 } 2663 2664 void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live, 2665 Error **errp) 2666 { 2667 QEMUFile *f; 2668 QIOChannelFile *ioc; 2669 int saved_vm_running; 2670 int ret; 2671 2672 if (!has_live) { 2673 /* live default to true so old version of Xen tool stack can have a 2674 * successfull live migration */ 2675 live = true; 2676 } 2677 2678 saved_vm_running = runstate_is_running(); 2679 vm_stop(RUN_STATE_SAVE_VM); 2680 global_state_store_running(); 2681 2682 ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT, 0660, errp); 2683 if (!ioc) { 2684 goto the_end; 2685 } 2686 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-save-state"); 2687 f = qemu_fopen_channel_output(QIO_CHANNEL(ioc)); 2688 object_unref(OBJECT(ioc)); 2689 ret = qemu_save_device_state(f); 2690 if (ret < 0 || qemu_fclose(f) < 0) { 2691 error_setg(errp, QERR_IO_ERROR); 2692 } else { 2693 /* libxl calls the QMP command "stop" before calling 2694 * "xen-save-devices-state" and in case of migration failure, libxl 2695 * would call "cont". 2696 * So call bdrv_inactivate_all (release locks) here to let the other 2697 * side of the migration take controle of the images. 2698 */ 2699 if (live && !saved_vm_running) { 2700 ret = bdrv_inactivate_all(); 2701 if (ret) { 2702 error_setg(errp, "%s: bdrv_inactivate_all() failed (%d)", 2703 __func__, ret); 2704 } 2705 } 2706 } 2707 2708 the_end: 2709 if (saved_vm_running) { 2710 vm_start(); 2711 } 2712 } 2713 2714 void qmp_xen_load_devices_state(const char *filename, Error **errp) 2715 { 2716 QEMUFile *f; 2717 QIOChannelFile *ioc; 2718 int ret; 2719 2720 /* Guest must be paused before loading the device state; the RAM state 2721 * will already have been loaded by xc 2722 */ 2723 if (runstate_is_running()) { 2724 error_setg(errp, "Cannot update device state while vm is running"); 2725 return; 2726 } 2727 vm_stop(RUN_STATE_RESTORE_VM); 2728 2729 ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0, errp); 2730 if (!ioc) { 2731 return; 2732 } 2733 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-load-state"); 2734 f = qemu_fopen_channel_input(QIO_CHANNEL(ioc)); 2735 object_unref(OBJECT(ioc)); 2736 2737 ret = qemu_loadvm_state(f); 2738 qemu_fclose(f); 2739 if (ret < 0) { 2740 error_setg(errp, QERR_IO_ERROR); 2741 } 2742 migration_incoming_state_destroy(); 2743 } 2744 2745 int load_snapshot(const char *name, Error **errp) 2746 { 2747 BlockDriverState *bs, *bs_vm_state; 2748 QEMUSnapshotInfo sn; 2749 QEMUFile *f; 2750 int ret; 2751 AioContext *aio_context; 2752 MigrationIncomingState *mis = migration_incoming_get_current(); 2753 2754 if (!replay_can_snapshot()) { 2755 error_setg(errp, "Record/replay does not allow loading snapshot " 2756 "right now. Try once more later."); 2757 return -EINVAL; 2758 } 2759 2760 if (!bdrv_all_can_snapshot(&bs)) { 2761 error_setg(errp, 2762 "Device '%s' is writable but does not support snapshots", 2763 bdrv_get_device_name(bs)); 2764 return -ENOTSUP; 2765 } 2766 ret = bdrv_all_find_snapshot(name, &bs); 2767 if (ret < 0) { 2768 error_setg(errp, 2769 "Device '%s' does not have the requested snapshot '%s'", 2770 bdrv_get_device_name(bs), name); 2771 return ret; 2772 } 2773 2774 bs_vm_state = bdrv_all_find_vmstate_bs(); 2775 if (!bs_vm_state) { 2776 error_setg(errp, "No block device supports snapshots"); 2777 return -ENOTSUP; 2778 } 2779 aio_context = bdrv_get_aio_context(bs_vm_state); 2780 2781 /* Don't even try to load empty VM states */ 2782 aio_context_acquire(aio_context); 2783 ret = bdrv_snapshot_find(bs_vm_state, &sn, name); 2784 aio_context_release(aio_context); 2785 if (ret < 0) { 2786 return ret; 2787 } else if (sn.vm_state_size == 0) { 2788 error_setg(errp, "This is a disk-only snapshot. Revert to it " 2789 " offline using qemu-img"); 2790 return -EINVAL; 2791 } 2792 2793 /* Flush all IO requests so they don't interfere with the new state. */ 2794 bdrv_drain_all_begin(); 2795 2796 ret = bdrv_all_goto_snapshot(name, &bs, errp); 2797 if (ret < 0) { 2798 error_prepend(errp, "Could not load snapshot '%s' on '%s': ", 2799 name, bdrv_get_device_name(bs)); 2800 goto err_drain; 2801 } 2802 2803 /* restore the VM state */ 2804 f = qemu_fopen_bdrv(bs_vm_state, 0); 2805 if (!f) { 2806 error_setg(errp, "Could not open VM state file"); 2807 ret = -EINVAL; 2808 goto err_drain; 2809 } 2810 2811 qemu_system_reset(SHUTDOWN_CAUSE_NONE); 2812 mis->from_src_file = f; 2813 2814 aio_context_acquire(aio_context); 2815 ret = qemu_loadvm_state(f); 2816 migration_incoming_state_destroy(); 2817 aio_context_release(aio_context); 2818 2819 bdrv_drain_all_end(); 2820 2821 if (ret < 0) { 2822 error_setg(errp, "Error %d while loading VM state", ret); 2823 return ret; 2824 } 2825 2826 return 0; 2827 2828 err_drain: 2829 bdrv_drain_all_end(); 2830 return ret; 2831 } 2832 2833 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev) 2834 { 2835 qemu_ram_set_idstr(mr->ram_block, 2836 memory_region_name(mr), dev); 2837 qemu_ram_set_migratable(mr->ram_block); 2838 } 2839 2840 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev) 2841 { 2842 qemu_ram_unset_idstr(mr->ram_block); 2843 qemu_ram_unset_migratable(mr->ram_block); 2844 } 2845 2846 void vmstate_register_ram_global(MemoryRegion *mr) 2847 { 2848 vmstate_register_ram(mr, NULL); 2849 } 2850 2851 bool vmstate_check_only_migratable(const VMStateDescription *vmsd) 2852 { 2853 /* check needed if --only-migratable is specified */ 2854 if (!only_migratable) { 2855 return true; 2856 } 2857 2858 return !(vmsd && vmsd->unmigratable); 2859 } 2860