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/runstate.h" 61 #include "sysemu/sysemu.h" 62 #include "qjson.h" 63 #include "migration/colo.h" 64 #include "qemu/bitmap.h" 65 #include "net/announce.h" 66 67 const unsigned int postcopy_ram_discard_version = 0; 68 69 /* Subcommands for QEMU_VM_COMMAND */ 70 enum qemu_vm_cmd { 71 MIG_CMD_INVALID = 0, /* Must be 0 */ 72 MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */ 73 MIG_CMD_PING, /* Request a PONG on the RP */ 74 75 MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just 76 warn we might want to do PC */ 77 MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming 78 pages as it's running. */ 79 MIG_CMD_POSTCOPY_RUN, /* Start execution */ 80 81 MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that 82 were previously sent during 83 precopy but are dirty. */ 84 MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */ 85 MIG_CMD_ENABLE_COLO, /* Enable COLO */ 86 MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */ 87 MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */ 88 MIG_CMD_MAX 89 }; 90 91 #define MAX_VM_CMD_PACKAGED_SIZE UINT32_MAX 92 static struct mig_cmd_args { 93 ssize_t len; /* -1 = variable */ 94 const char *name; 95 } mig_cmd_args[] = { 96 [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" }, 97 [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" }, 98 [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" }, 99 [MIG_CMD_POSTCOPY_ADVISE] = { .len = -1, .name = "POSTCOPY_ADVISE" }, 100 [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" }, 101 [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" }, 102 [MIG_CMD_POSTCOPY_RAM_DISCARD] = { 103 .len = -1, .name = "POSTCOPY_RAM_DISCARD" }, 104 [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" }, 105 [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" }, 106 [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" }, 107 [MIG_CMD_MAX] = { .len = -1, .name = "MAX" }, 108 }; 109 110 /* Note for MIG_CMD_POSTCOPY_ADVISE: 111 * The format of arguments is depending on postcopy mode: 112 * - postcopy RAM only 113 * uint64_t host page size 114 * uint64_t taget page size 115 * 116 * - postcopy RAM and postcopy dirty bitmaps 117 * format is the same as for postcopy RAM only 118 * 119 * - postcopy dirty bitmaps only 120 * Nothing. Command length field is 0. 121 * 122 * Be careful: adding a new postcopy entity with some other parameters should 123 * not break format self-description ability. Good way is to introduce some 124 * generic extendable format with an exception for two old entities. 125 */ 126 127 /***********************************************************/ 128 /* savevm/loadvm support */ 129 130 static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, 131 int64_t pos) 132 { 133 int ret; 134 QEMUIOVector qiov; 135 136 qemu_iovec_init_external(&qiov, iov, iovcnt); 137 ret = bdrv_writev_vmstate(opaque, &qiov, pos); 138 if (ret < 0) { 139 return ret; 140 } 141 142 return qiov.size; 143 } 144 145 static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, 146 size_t size) 147 { 148 return bdrv_load_vmstate(opaque, buf, pos, size); 149 } 150 151 static int bdrv_fclose(void *opaque) 152 { 153 return bdrv_flush(opaque); 154 } 155 156 static const QEMUFileOps bdrv_read_ops = { 157 .get_buffer = block_get_buffer, 158 .close = bdrv_fclose 159 }; 160 161 static const QEMUFileOps bdrv_write_ops = { 162 .writev_buffer = block_writev_buffer, 163 .close = bdrv_fclose 164 }; 165 166 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable) 167 { 168 if (is_writable) { 169 return qemu_fopen_ops(bs, &bdrv_write_ops); 170 } 171 return qemu_fopen_ops(bs, &bdrv_read_ops); 172 } 173 174 175 /* QEMUFile timer support. 176 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c 177 */ 178 179 void timer_put(QEMUFile *f, QEMUTimer *ts) 180 { 181 uint64_t expire_time; 182 183 expire_time = timer_expire_time_ns(ts); 184 qemu_put_be64(f, expire_time); 185 } 186 187 void timer_get(QEMUFile *f, QEMUTimer *ts) 188 { 189 uint64_t expire_time; 190 191 expire_time = qemu_get_be64(f); 192 if (expire_time != -1) { 193 timer_mod_ns(ts, expire_time); 194 } else { 195 timer_del(ts); 196 } 197 } 198 199 200 /* VMState timer support. 201 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c 202 */ 203 204 static int get_timer(QEMUFile *f, void *pv, size_t size, 205 const VMStateField *field) 206 { 207 QEMUTimer *v = pv; 208 timer_get(f, v); 209 return 0; 210 } 211 212 static int put_timer(QEMUFile *f, void *pv, size_t size, 213 const VMStateField *field, QJSON *vmdesc) 214 { 215 QEMUTimer *v = pv; 216 timer_put(f, v); 217 218 return 0; 219 } 220 221 const VMStateInfo vmstate_info_timer = { 222 .name = "timer", 223 .get = get_timer, 224 .put = put_timer, 225 }; 226 227 228 typedef struct CompatEntry { 229 char idstr[256]; 230 int instance_id; 231 } CompatEntry; 232 233 typedef struct SaveStateEntry { 234 QTAILQ_ENTRY(SaveStateEntry) entry; 235 char idstr[256]; 236 int instance_id; 237 int alias_id; 238 int version_id; 239 /* version id read from the stream */ 240 int load_version_id; 241 int section_id; 242 /* section id read from the stream */ 243 int load_section_id; 244 const SaveVMHandlers *ops; 245 const VMStateDescription *vmsd; 246 void *opaque; 247 CompatEntry *compat; 248 int is_ram; 249 } SaveStateEntry; 250 251 typedef struct SaveState { 252 QTAILQ_HEAD(, SaveStateEntry) handlers; 253 int global_section_id; 254 uint32_t len; 255 const char *name; 256 uint32_t target_page_bits; 257 uint32_t caps_count; 258 MigrationCapability *capabilities; 259 } SaveState; 260 261 static SaveState savevm_state = { 262 .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers), 263 .global_section_id = 0, 264 }; 265 266 static bool should_validate_capability(int capability) 267 { 268 assert(capability >= 0 && capability < MIGRATION_CAPABILITY__MAX); 269 /* Validate only new capabilities to keep compatibility. */ 270 switch (capability) { 271 case MIGRATION_CAPABILITY_X_IGNORE_SHARED: 272 return true; 273 default: 274 return false; 275 } 276 } 277 278 static uint32_t get_validatable_capabilities_count(void) 279 { 280 MigrationState *s = migrate_get_current(); 281 uint32_t result = 0; 282 int i; 283 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 284 if (should_validate_capability(i) && s->enabled_capabilities[i]) { 285 result++; 286 } 287 } 288 return result; 289 } 290 291 static int configuration_pre_save(void *opaque) 292 { 293 SaveState *state = opaque; 294 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 295 MigrationState *s = migrate_get_current(); 296 int i, j; 297 298 state->len = strlen(current_name); 299 state->name = current_name; 300 state->target_page_bits = qemu_target_page_bits(); 301 302 state->caps_count = get_validatable_capabilities_count(); 303 state->capabilities = g_renew(MigrationCapability, state->capabilities, 304 state->caps_count); 305 for (i = j = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 306 if (should_validate_capability(i) && s->enabled_capabilities[i]) { 307 state->capabilities[j++] = i; 308 } 309 } 310 311 return 0; 312 } 313 314 static int configuration_pre_load(void *opaque) 315 { 316 SaveState *state = opaque; 317 318 /* If there is no target-page-bits subsection it means the source 319 * predates the variable-target-page-bits support and is using the 320 * minimum possible value for this CPU. 321 */ 322 state->target_page_bits = qemu_target_page_bits_min(); 323 return 0; 324 } 325 326 static bool configuration_validate_capabilities(SaveState *state) 327 { 328 bool ret = true; 329 MigrationState *s = migrate_get_current(); 330 unsigned long *source_caps_bm; 331 int i; 332 333 source_caps_bm = bitmap_new(MIGRATION_CAPABILITY__MAX); 334 for (i = 0; i < state->caps_count; i++) { 335 MigrationCapability capability = state->capabilities[i]; 336 set_bit(capability, source_caps_bm); 337 } 338 339 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 340 bool source_state, target_state; 341 if (!should_validate_capability(i)) { 342 continue; 343 } 344 source_state = test_bit(i, source_caps_bm); 345 target_state = s->enabled_capabilities[i]; 346 if (source_state != target_state) { 347 error_report("Capability %s is %s, but received capability is %s", 348 MigrationCapability_str(i), 349 target_state ? "on" : "off", 350 source_state ? "on" : "off"); 351 ret = false; 352 /* Don't break here to report all failed capabilities */ 353 } 354 } 355 356 g_free(source_caps_bm); 357 return ret; 358 } 359 360 static int configuration_post_load(void *opaque, int version_id) 361 { 362 SaveState *state = opaque; 363 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 364 365 if (strncmp(state->name, current_name, state->len) != 0) { 366 error_report("Machine type received is '%.*s' and local is '%s'", 367 (int) state->len, state->name, current_name); 368 return -EINVAL; 369 } 370 371 if (state->target_page_bits != qemu_target_page_bits()) { 372 error_report("Received TARGET_PAGE_BITS is %d but local is %d", 373 state->target_page_bits, qemu_target_page_bits()); 374 return -EINVAL; 375 } 376 377 if (!configuration_validate_capabilities(state)) { 378 return -EINVAL; 379 } 380 381 return 0; 382 } 383 384 static int get_capability(QEMUFile *f, void *pv, size_t size, 385 const VMStateField *field) 386 { 387 MigrationCapability *capability = pv; 388 char capability_str[UINT8_MAX + 1]; 389 uint8_t len; 390 int i; 391 392 len = qemu_get_byte(f); 393 qemu_get_buffer(f, (uint8_t *)capability_str, len); 394 capability_str[len] = '\0'; 395 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 396 if (!strcmp(MigrationCapability_str(i), capability_str)) { 397 *capability = i; 398 return 0; 399 } 400 } 401 error_report("Received unknown capability %s", capability_str); 402 return -EINVAL; 403 } 404 405 static int put_capability(QEMUFile *f, void *pv, size_t size, 406 const VMStateField *field, QJSON *vmdesc) 407 { 408 MigrationCapability *capability = pv; 409 const char *capability_str = MigrationCapability_str(*capability); 410 size_t len = strlen(capability_str); 411 assert(len <= UINT8_MAX); 412 413 qemu_put_byte(f, len); 414 qemu_put_buffer(f, (uint8_t *)capability_str, len); 415 return 0; 416 } 417 418 static const VMStateInfo vmstate_info_capability = { 419 .name = "capability", 420 .get = get_capability, 421 .put = put_capability, 422 }; 423 424 /* The target-page-bits subsection is present only if the 425 * target page size is not the same as the default (ie the 426 * minimum page size for a variable-page-size guest CPU). 427 * If it is present then it contains the actual target page 428 * bits for the machine, and migration will fail if the 429 * two ends don't agree about it. 430 */ 431 static bool vmstate_target_page_bits_needed(void *opaque) 432 { 433 return qemu_target_page_bits() 434 > qemu_target_page_bits_min(); 435 } 436 437 static const VMStateDescription vmstate_target_page_bits = { 438 .name = "configuration/target-page-bits", 439 .version_id = 1, 440 .minimum_version_id = 1, 441 .needed = vmstate_target_page_bits_needed, 442 .fields = (VMStateField[]) { 443 VMSTATE_UINT32(target_page_bits, SaveState), 444 VMSTATE_END_OF_LIST() 445 } 446 }; 447 448 static bool vmstate_capabilites_needed(void *opaque) 449 { 450 return get_validatable_capabilities_count() > 0; 451 } 452 453 static const VMStateDescription vmstate_capabilites = { 454 .name = "configuration/capabilities", 455 .version_id = 1, 456 .minimum_version_id = 1, 457 .needed = vmstate_capabilites_needed, 458 .fields = (VMStateField[]) { 459 VMSTATE_UINT32_V(caps_count, SaveState, 1), 460 VMSTATE_VARRAY_UINT32_ALLOC(capabilities, SaveState, caps_count, 1, 461 vmstate_info_capability, 462 MigrationCapability), 463 VMSTATE_END_OF_LIST() 464 } 465 }; 466 467 static const VMStateDescription vmstate_configuration = { 468 .name = "configuration", 469 .version_id = 1, 470 .pre_load = configuration_pre_load, 471 .post_load = configuration_post_load, 472 .pre_save = configuration_pre_save, 473 .fields = (VMStateField[]) { 474 VMSTATE_UINT32(len, SaveState), 475 VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len), 476 VMSTATE_END_OF_LIST() 477 }, 478 .subsections = (const VMStateDescription*[]) { 479 &vmstate_target_page_bits, 480 &vmstate_capabilites, 481 NULL 482 } 483 }; 484 485 static void dump_vmstate_vmsd(FILE *out_file, 486 const VMStateDescription *vmsd, int indent, 487 bool is_subsection); 488 489 static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field, 490 int indent) 491 { 492 fprintf(out_file, "%*s{\n", indent, ""); 493 indent += 2; 494 fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name); 495 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 496 field->version_id); 497 fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "", 498 field->field_exists ? "true" : "false"); 499 fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size); 500 if (field->vmsd != NULL) { 501 fprintf(out_file, ",\n"); 502 dump_vmstate_vmsd(out_file, field->vmsd, indent, false); 503 } 504 fprintf(out_file, "\n%*s}", indent - 2, ""); 505 } 506 507 static void dump_vmstate_vmss(FILE *out_file, 508 const VMStateDescription **subsection, 509 int indent) 510 { 511 if (*subsection != NULL) { 512 dump_vmstate_vmsd(out_file, *subsection, indent, true); 513 } 514 } 515 516 static void dump_vmstate_vmsd(FILE *out_file, 517 const VMStateDescription *vmsd, int indent, 518 bool is_subsection) 519 { 520 if (is_subsection) { 521 fprintf(out_file, "%*s{\n", indent, ""); 522 } else { 523 fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description"); 524 } 525 indent += 2; 526 fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name); 527 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 528 vmsd->version_id); 529 fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "", 530 vmsd->minimum_version_id); 531 if (vmsd->fields != NULL) { 532 const VMStateField *field = vmsd->fields; 533 bool first; 534 535 fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, ""); 536 first = true; 537 while (field->name != NULL) { 538 if (field->flags & VMS_MUST_EXIST) { 539 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */ 540 field++; 541 continue; 542 } 543 if (!first) { 544 fprintf(out_file, ",\n"); 545 } 546 dump_vmstate_vmsf(out_file, field, indent + 2); 547 field++; 548 first = false; 549 } 550 fprintf(out_file, "\n%*s]", indent, ""); 551 } 552 if (vmsd->subsections != NULL) { 553 const VMStateDescription **subsection = vmsd->subsections; 554 bool first; 555 556 fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, ""); 557 first = true; 558 while (*subsection != NULL) { 559 if (!first) { 560 fprintf(out_file, ",\n"); 561 } 562 dump_vmstate_vmss(out_file, subsection, indent + 2); 563 subsection++; 564 first = false; 565 } 566 fprintf(out_file, "\n%*s]", indent, ""); 567 } 568 fprintf(out_file, "\n%*s}", indent - 2, ""); 569 } 570 571 static void dump_machine_type(FILE *out_file) 572 { 573 MachineClass *mc; 574 575 mc = MACHINE_GET_CLASS(current_machine); 576 577 fprintf(out_file, " \"vmschkmachine\": {\n"); 578 fprintf(out_file, " \"Name\": \"%s\"\n", mc->name); 579 fprintf(out_file, " },\n"); 580 } 581 582 void dump_vmstate_json_to_file(FILE *out_file) 583 { 584 GSList *list, *elt; 585 bool first; 586 587 fprintf(out_file, "{\n"); 588 dump_machine_type(out_file); 589 590 first = true; 591 list = object_class_get_list(TYPE_DEVICE, true); 592 for (elt = list; elt; elt = elt->next) { 593 DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data, 594 TYPE_DEVICE); 595 const char *name; 596 int indent = 2; 597 598 if (!dc->vmsd) { 599 continue; 600 } 601 602 if (!first) { 603 fprintf(out_file, ",\n"); 604 } 605 name = object_class_get_name(OBJECT_CLASS(dc)); 606 fprintf(out_file, "%*s\"%s\": {\n", indent, "", name); 607 indent += 2; 608 fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name); 609 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 610 dc->vmsd->version_id); 611 fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "", 612 dc->vmsd->minimum_version_id); 613 614 dump_vmstate_vmsd(out_file, dc->vmsd, indent, false); 615 616 fprintf(out_file, "\n%*s}", indent - 2, ""); 617 first = false; 618 } 619 fprintf(out_file, "\n}\n"); 620 fclose(out_file); 621 } 622 623 static int calculate_new_instance_id(const char *idstr) 624 { 625 SaveStateEntry *se; 626 int instance_id = 0; 627 628 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 629 if (strcmp(idstr, se->idstr) == 0 630 && instance_id <= se->instance_id) { 631 instance_id = se->instance_id + 1; 632 } 633 } 634 return instance_id; 635 } 636 637 static int calculate_compat_instance_id(const char *idstr) 638 { 639 SaveStateEntry *se; 640 int instance_id = 0; 641 642 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 643 if (!se->compat) { 644 continue; 645 } 646 647 if (strcmp(idstr, se->compat->idstr) == 0 648 && instance_id <= se->compat->instance_id) { 649 instance_id = se->compat->instance_id + 1; 650 } 651 } 652 return instance_id; 653 } 654 655 static inline MigrationPriority save_state_priority(SaveStateEntry *se) 656 { 657 if (se->vmsd) { 658 return se->vmsd->priority; 659 } 660 return MIG_PRI_DEFAULT; 661 } 662 663 static void savevm_state_handler_insert(SaveStateEntry *nse) 664 { 665 MigrationPriority priority = save_state_priority(nse); 666 SaveStateEntry *se; 667 668 assert(priority <= MIG_PRI_MAX); 669 670 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 671 if (save_state_priority(se) < priority) { 672 break; 673 } 674 } 675 676 if (se) { 677 QTAILQ_INSERT_BEFORE(se, nse, entry); 678 } else { 679 QTAILQ_INSERT_TAIL(&savevm_state.handlers, nse, entry); 680 } 681 } 682 683 /* TODO: Individual devices generally have very little idea about the rest 684 of the system, so instance_id should be removed/replaced. 685 Meanwhile pass -1 as instance_id if you do not already have a clearly 686 distinguishing id for all instances of your device class. */ 687 int register_savevm_live(DeviceState *dev, 688 const char *idstr, 689 int instance_id, 690 int version_id, 691 const SaveVMHandlers *ops, 692 void *opaque) 693 { 694 SaveStateEntry *se; 695 696 se = g_new0(SaveStateEntry, 1); 697 se->version_id = version_id; 698 se->section_id = savevm_state.global_section_id++; 699 se->ops = ops; 700 se->opaque = opaque; 701 se->vmsd = NULL; 702 /* if this is a live_savem then set is_ram */ 703 if (ops->save_setup != NULL) { 704 se->is_ram = 1; 705 } 706 707 if (dev) { 708 char *id = qdev_get_dev_path(dev); 709 if (id) { 710 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 711 sizeof(se->idstr)) { 712 error_report("Path too long for VMState (%s)", id); 713 g_free(id); 714 g_free(se); 715 716 return -1; 717 } 718 g_free(id); 719 720 se->compat = g_new0(CompatEntry, 1); 721 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr); 722 se->compat->instance_id = instance_id == -1 ? 723 calculate_compat_instance_id(idstr) : instance_id; 724 instance_id = -1; 725 } 726 } 727 pstrcat(se->idstr, sizeof(se->idstr), idstr); 728 729 if (instance_id == -1) { 730 se->instance_id = calculate_new_instance_id(se->idstr); 731 } else { 732 se->instance_id = instance_id; 733 } 734 assert(!se->compat || se->instance_id == 0); 735 savevm_state_handler_insert(se); 736 return 0; 737 } 738 739 void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque) 740 { 741 SaveStateEntry *se, *new_se; 742 char id[256] = ""; 743 744 if (dev) { 745 char *path = qdev_get_dev_path(dev); 746 if (path) { 747 pstrcpy(id, sizeof(id), path); 748 pstrcat(id, sizeof(id), "/"); 749 g_free(path); 750 } 751 } 752 pstrcat(id, sizeof(id), idstr); 753 754 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 755 if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) { 756 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 757 g_free(se->compat); 758 g_free(se); 759 } 760 } 761 } 762 763 int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, 764 const VMStateDescription *vmsd, 765 void *opaque, int alias_id, 766 int required_for_version, 767 Error **errp) 768 { 769 SaveStateEntry *se; 770 771 /* If this triggers, alias support can be dropped for the vmsd. */ 772 assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id); 773 774 se = g_new0(SaveStateEntry, 1); 775 se->version_id = vmsd->version_id; 776 se->section_id = savevm_state.global_section_id++; 777 se->opaque = opaque; 778 se->vmsd = vmsd; 779 se->alias_id = alias_id; 780 781 if (dev) { 782 char *id = qdev_get_dev_path(dev); 783 if (id) { 784 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 785 sizeof(se->idstr)) { 786 error_setg(errp, "Path too long for VMState (%s)", id); 787 g_free(id); 788 g_free(se); 789 790 return -1; 791 } 792 g_free(id); 793 794 se->compat = g_new0(CompatEntry, 1); 795 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name); 796 se->compat->instance_id = instance_id == -1 ? 797 calculate_compat_instance_id(vmsd->name) : instance_id; 798 instance_id = -1; 799 } 800 } 801 pstrcat(se->idstr, sizeof(se->idstr), vmsd->name); 802 803 if (instance_id == -1) { 804 se->instance_id = calculate_new_instance_id(se->idstr); 805 } else { 806 se->instance_id = instance_id; 807 } 808 assert(!se->compat || se->instance_id == 0); 809 savevm_state_handler_insert(se); 810 return 0; 811 } 812 813 void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd, 814 void *opaque) 815 { 816 SaveStateEntry *se, *new_se; 817 818 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 819 if (se->vmsd == vmsd && se->opaque == opaque) { 820 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 821 g_free(se->compat); 822 g_free(se); 823 } 824 } 825 } 826 827 static int vmstate_load(QEMUFile *f, SaveStateEntry *se) 828 { 829 trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 830 if (!se->vmsd) { /* Old style */ 831 return se->ops->load_state(f, se->opaque, se->load_version_id); 832 } 833 return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id); 834 } 835 836 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc) 837 { 838 int64_t old_offset, size; 839 840 old_offset = qemu_ftell_fast(f); 841 se->ops->save_state(f, se->opaque); 842 size = qemu_ftell_fast(f) - old_offset; 843 844 if (vmdesc) { 845 json_prop_int(vmdesc, "size", size); 846 json_start_array(vmdesc, "fields"); 847 json_start_object(vmdesc, NULL); 848 json_prop_str(vmdesc, "name", "data"); 849 json_prop_int(vmdesc, "size", size); 850 json_prop_str(vmdesc, "type", "buffer"); 851 json_end_object(vmdesc); 852 json_end_array(vmdesc); 853 } 854 } 855 856 static int vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc) 857 { 858 trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 859 if (!se->vmsd) { 860 vmstate_save_old_style(f, se, vmdesc); 861 return 0; 862 } 863 return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc); 864 } 865 866 /* 867 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL) 868 */ 869 static void save_section_header(QEMUFile *f, SaveStateEntry *se, 870 uint8_t section_type) 871 { 872 qemu_put_byte(f, section_type); 873 qemu_put_be32(f, se->section_id); 874 875 if (section_type == QEMU_VM_SECTION_FULL || 876 section_type == QEMU_VM_SECTION_START) { 877 /* ID string */ 878 size_t len = strlen(se->idstr); 879 qemu_put_byte(f, len); 880 qemu_put_buffer(f, (uint8_t *)se->idstr, len); 881 882 qemu_put_be32(f, se->instance_id); 883 qemu_put_be32(f, se->version_id); 884 } 885 } 886 887 /* 888 * Write a footer onto device sections that catches cases misformatted device 889 * sections. 890 */ 891 static void save_section_footer(QEMUFile *f, SaveStateEntry *se) 892 { 893 if (migrate_get_current()->send_section_footer) { 894 qemu_put_byte(f, QEMU_VM_SECTION_FOOTER); 895 qemu_put_be32(f, se->section_id); 896 } 897 } 898 899 /** 900 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the 901 * command and associated data. 902 * 903 * @f: File to send command on 904 * @command: Command type to send 905 * @len: Length of associated data 906 * @data: Data associated with command. 907 */ 908 static void qemu_savevm_command_send(QEMUFile *f, 909 enum qemu_vm_cmd command, 910 uint16_t len, 911 uint8_t *data) 912 { 913 trace_savevm_command_send(command, len); 914 qemu_put_byte(f, QEMU_VM_COMMAND); 915 qemu_put_be16(f, (uint16_t)command); 916 qemu_put_be16(f, len); 917 qemu_put_buffer(f, data, len); 918 qemu_fflush(f); 919 } 920 921 void qemu_savevm_send_colo_enable(QEMUFile *f) 922 { 923 trace_savevm_send_colo_enable(); 924 qemu_savevm_command_send(f, MIG_CMD_ENABLE_COLO, 0, NULL); 925 } 926 927 void qemu_savevm_send_ping(QEMUFile *f, uint32_t value) 928 { 929 uint32_t buf; 930 931 trace_savevm_send_ping(value); 932 buf = cpu_to_be32(value); 933 qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf); 934 } 935 936 void qemu_savevm_send_open_return_path(QEMUFile *f) 937 { 938 trace_savevm_send_open_return_path(); 939 qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL); 940 } 941 942 /* We have a buffer of data to send; we don't want that all to be loaded 943 * by the command itself, so the command contains just the length of the 944 * extra buffer that we then send straight after it. 945 * TODO: Must be a better way to organise that 946 * 947 * Returns: 948 * 0 on success 949 * -ve on error 950 */ 951 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len) 952 { 953 uint32_t tmp; 954 955 if (len > MAX_VM_CMD_PACKAGED_SIZE) { 956 error_report("%s: Unreasonably large packaged state: %zu", 957 __func__, len); 958 return -1; 959 } 960 961 tmp = cpu_to_be32(len); 962 963 trace_qemu_savevm_send_packaged(); 964 qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp); 965 966 qemu_put_buffer(f, buf, len); 967 968 return 0; 969 } 970 971 /* Send prior to any postcopy transfer */ 972 void qemu_savevm_send_postcopy_advise(QEMUFile *f) 973 { 974 if (migrate_postcopy_ram()) { 975 uint64_t tmp[2]; 976 tmp[0] = cpu_to_be64(ram_pagesize_summary()); 977 tmp[1] = cpu_to_be64(qemu_target_page_size()); 978 979 trace_qemu_savevm_send_postcopy_advise(); 980 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 981 16, (uint8_t *)tmp); 982 } else { 983 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 0, NULL); 984 } 985 } 986 987 /* Sent prior to starting the destination running in postcopy, discard pages 988 * that have already been sent but redirtied on the source. 989 * CMD_POSTCOPY_RAM_DISCARD consist of: 990 * byte version (0) 991 * byte Length of name field (not including 0) 992 * n x byte RAM block name 993 * byte 0 terminator (just for safety) 994 * n x Byte ranges within the named RAMBlock 995 * be64 Start of the range 996 * be64 Length 997 * 998 * name: RAMBlock name that these entries are part of 999 * len: Number of page entries 1000 * start_list: 'len' addresses 1001 * length_list: 'len' addresses 1002 * 1003 */ 1004 void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name, 1005 uint16_t len, 1006 uint64_t *start_list, 1007 uint64_t *length_list) 1008 { 1009 uint8_t *buf; 1010 uint16_t tmplen; 1011 uint16_t t; 1012 size_t name_len = strlen(name); 1013 1014 trace_qemu_savevm_send_postcopy_ram_discard(name, len); 1015 assert(name_len < 256); 1016 buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len); 1017 buf[0] = postcopy_ram_discard_version; 1018 buf[1] = name_len; 1019 memcpy(buf + 2, name, name_len); 1020 tmplen = 2 + name_len; 1021 buf[tmplen++] = '\0'; 1022 1023 for (t = 0; t < len; t++) { 1024 stq_be_p(buf + tmplen, start_list[t]); 1025 tmplen += 8; 1026 stq_be_p(buf + tmplen, length_list[t]); 1027 tmplen += 8; 1028 } 1029 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf); 1030 g_free(buf); 1031 } 1032 1033 /* Get the destination into a state where it can receive postcopy data. */ 1034 void qemu_savevm_send_postcopy_listen(QEMUFile *f) 1035 { 1036 trace_savevm_send_postcopy_listen(); 1037 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL); 1038 } 1039 1040 /* Kick the destination into running */ 1041 void qemu_savevm_send_postcopy_run(QEMUFile *f) 1042 { 1043 trace_savevm_send_postcopy_run(); 1044 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL); 1045 } 1046 1047 void qemu_savevm_send_postcopy_resume(QEMUFile *f) 1048 { 1049 trace_savevm_send_postcopy_resume(); 1050 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL); 1051 } 1052 1053 void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name) 1054 { 1055 size_t len; 1056 char buf[256]; 1057 1058 trace_savevm_send_recv_bitmap(block_name); 1059 1060 buf[0] = len = strlen(block_name); 1061 memcpy(buf + 1, block_name, len); 1062 1063 qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf); 1064 } 1065 1066 bool qemu_savevm_state_blocked(Error **errp) 1067 { 1068 SaveStateEntry *se; 1069 1070 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1071 if (se->vmsd && se->vmsd->unmigratable) { 1072 error_setg(errp, "State blocked by non-migratable device '%s'", 1073 se->idstr); 1074 return true; 1075 } 1076 } 1077 return false; 1078 } 1079 1080 void qemu_savevm_state_header(QEMUFile *f) 1081 { 1082 trace_savevm_state_header(); 1083 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1084 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1085 1086 if (migrate_get_current()->send_configuration) { 1087 qemu_put_byte(f, QEMU_VM_CONFIGURATION); 1088 vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0); 1089 } 1090 } 1091 1092 void qemu_savevm_state_setup(QEMUFile *f) 1093 { 1094 SaveStateEntry *se; 1095 Error *local_err = NULL; 1096 int ret; 1097 1098 trace_savevm_state_setup(); 1099 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1100 if (!se->ops || !se->ops->save_setup) { 1101 continue; 1102 } 1103 if (se->ops && se->ops->is_active) { 1104 if (!se->ops->is_active(se->opaque)) { 1105 continue; 1106 } 1107 } 1108 save_section_header(f, se, QEMU_VM_SECTION_START); 1109 1110 ret = se->ops->save_setup(f, se->opaque); 1111 save_section_footer(f, se); 1112 if (ret < 0) { 1113 qemu_file_set_error(f, ret); 1114 break; 1115 } 1116 } 1117 1118 if (precopy_notify(PRECOPY_NOTIFY_SETUP, &local_err)) { 1119 error_report_err(local_err); 1120 } 1121 } 1122 1123 int qemu_savevm_state_resume_prepare(MigrationState *s) 1124 { 1125 SaveStateEntry *se; 1126 int ret; 1127 1128 trace_savevm_state_resume_prepare(); 1129 1130 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1131 if (!se->ops || !se->ops->resume_prepare) { 1132 continue; 1133 } 1134 if (se->ops && se->ops->is_active) { 1135 if (!se->ops->is_active(se->opaque)) { 1136 continue; 1137 } 1138 } 1139 ret = se->ops->resume_prepare(s, se->opaque); 1140 if (ret < 0) { 1141 return ret; 1142 } 1143 } 1144 1145 return 0; 1146 } 1147 1148 /* 1149 * this function has three return values: 1150 * negative: there was one error, and we have -errno. 1151 * 0 : We haven't finished, caller have to go again 1152 * 1 : We have finished, we can go to complete phase 1153 */ 1154 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy) 1155 { 1156 SaveStateEntry *se; 1157 int ret = 1; 1158 1159 trace_savevm_state_iterate(); 1160 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1161 if (!se->ops || !se->ops->save_live_iterate) { 1162 continue; 1163 } 1164 if (se->ops->is_active && 1165 !se->ops->is_active(se->opaque)) { 1166 continue; 1167 } 1168 if (se->ops->is_active_iterate && 1169 !se->ops->is_active_iterate(se->opaque)) { 1170 continue; 1171 } 1172 /* 1173 * In the postcopy phase, any device that doesn't know how to 1174 * do postcopy should have saved it's state in the _complete 1175 * call that's already run, it might get confused if we call 1176 * iterate afterwards. 1177 */ 1178 if (postcopy && 1179 !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) { 1180 continue; 1181 } 1182 if (qemu_file_rate_limit(f)) { 1183 return 0; 1184 } 1185 trace_savevm_section_start(se->idstr, se->section_id); 1186 1187 save_section_header(f, se, QEMU_VM_SECTION_PART); 1188 1189 ret = se->ops->save_live_iterate(f, se->opaque); 1190 trace_savevm_section_end(se->idstr, se->section_id, ret); 1191 save_section_footer(f, se); 1192 1193 if (ret < 0) { 1194 qemu_file_set_error(f, ret); 1195 } 1196 if (ret <= 0) { 1197 /* Do not proceed to the next vmstate before this one reported 1198 completion of the current stage. This serializes the migration 1199 and reduces the probability that a faster changing state is 1200 synchronized over and over again. */ 1201 break; 1202 } 1203 } 1204 return ret; 1205 } 1206 1207 static bool should_send_vmdesc(void) 1208 { 1209 MachineState *machine = MACHINE(qdev_get_machine()); 1210 bool in_postcopy = migration_in_postcopy(); 1211 return !machine->suppress_vmdesc && !in_postcopy; 1212 } 1213 1214 /* 1215 * Calls the save_live_complete_postcopy methods 1216 * causing the last few pages to be sent immediately and doing any associated 1217 * cleanup. 1218 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete 1219 * all the other devices, but that happens at the point we switch to postcopy. 1220 */ 1221 void qemu_savevm_state_complete_postcopy(QEMUFile *f) 1222 { 1223 SaveStateEntry *se; 1224 int ret; 1225 1226 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1227 if (!se->ops || !se->ops->save_live_complete_postcopy) { 1228 continue; 1229 } 1230 if (se->ops && se->ops->is_active) { 1231 if (!se->ops->is_active(se->opaque)) { 1232 continue; 1233 } 1234 } 1235 trace_savevm_section_start(se->idstr, se->section_id); 1236 /* Section type */ 1237 qemu_put_byte(f, QEMU_VM_SECTION_END); 1238 qemu_put_be32(f, se->section_id); 1239 1240 ret = se->ops->save_live_complete_postcopy(f, se->opaque); 1241 trace_savevm_section_end(se->idstr, se->section_id, ret); 1242 save_section_footer(f, se); 1243 if (ret < 0) { 1244 qemu_file_set_error(f, ret); 1245 return; 1246 } 1247 } 1248 1249 qemu_put_byte(f, QEMU_VM_EOF); 1250 qemu_fflush(f); 1251 } 1252 1253 int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only, 1254 bool inactivate_disks) 1255 { 1256 QJSON *vmdesc; 1257 int vmdesc_len; 1258 SaveStateEntry *se; 1259 int ret; 1260 bool in_postcopy = migration_in_postcopy(); 1261 Error *local_err = NULL; 1262 1263 if (precopy_notify(PRECOPY_NOTIFY_COMPLETE, &local_err)) { 1264 error_report_err(local_err); 1265 } 1266 1267 trace_savevm_state_complete_precopy(); 1268 1269 cpu_synchronize_all_states(); 1270 1271 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1272 if (!se->ops || 1273 (in_postcopy && se->ops->has_postcopy && 1274 se->ops->has_postcopy(se->opaque)) || 1275 (in_postcopy && !iterable_only) || 1276 !se->ops->save_live_complete_precopy) { 1277 continue; 1278 } 1279 1280 if (se->ops && se->ops->is_active) { 1281 if (!se->ops->is_active(se->opaque)) { 1282 continue; 1283 } 1284 } 1285 trace_savevm_section_start(se->idstr, se->section_id); 1286 1287 save_section_header(f, se, QEMU_VM_SECTION_END); 1288 1289 ret = se->ops->save_live_complete_precopy(f, se->opaque); 1290 trace_savevm_section_end(se->idstr, se->section_id, ret); 1291 save_section_footer(f, se); 1292 if (ret < 0) { 1293 qemu_file_set_error(f, ret); 1294 return -1; 1295 } 1296 } 1297 1298 if (iterable_only) { 1299 return 0; 1300 } 1301 1302 vmdesc = qjson_new(); 1303 json_prop_int(vmdesc, "page_size", qemu_target_page_size()); 1304 json_start_array(vmdesc, "devices"); 1305 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1306 1307 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1308 continue; 1309 } 1310 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1311 trace_savevm_section_skip(se->idstr, se->section_id); 1312 continue; 1313 } 1314 1315 trace_savevm_section_start(se->idstr, se->section_id); 1316 1317 json_start_object(vmdesc, NULL); 1318 json_prop_str(vmdesc, "name", se->idstr); 1319 json_prop_int(vmdesc, "instance_id", se->instance_id); 1320 1321 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1322 ret = vmstate_save(f, se, vmdesc); 1323 if (ret) { 1324 qemu_file_set_error(f, ret); 1325 return ret; 1326 } 1327 trace_savevm_section_end(se->idstr, se->section_id, 0); 1328 save_section_footer(f, se); 1329 1330 json_end_object(vmdesc); 1331 } 1332 1333 if (inactivate_disks) { 1334 /* Inactivate before sending QEMU_VM_EOF so that the 1335 * bdrv_invalidate_cache_all() on the other end won't fail. */ 1336 ret = bdrv_inactivate_all(); 1337 if (ret) { 1338 error_report("%s: bdrv_inactivate_all() failed (%d)", 1339 __func__, ret); 1340 qemu_file_set_error(f, ret); 1341 return ret; 1342 } 1343 } 1344 if (!in_postcopy) { 1345 /* Postcopy stream will still be going */ 1346 qemu_put_byte(f, QEMU_VM_EOF); 1347 } 1348 1349 json_end_array(vmdesc); 1350 qjson_finish(vmdesc); 1351 vmdesc_len = strlen(qjson_get_str(vmdesc)); 1352 1353 if (should_send_vmdesc()) { 1354 qemu_put_byte(f, QEMU_VM_VMDESCRIPTION); 1355 qemu_put_be32(f, vmdesc_len); 1356 qemu_put_buffer(f, (uint8_t *)qjson_get_str(vmdesc), vmdesc_len); 1357 } 1358 qjson_destroy(vmdesc); 1359 1360 qemu_fflush(f); 1361 return 0; 1362 } 1363 1364 /* Give an estimate of the amount left to be transferred, 1365 * the result is split into the amount for units that can and 1366 * for units that can't do postcopy. 1367 */ 1368 void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size, 1369 uint64_t *res_precopy_only, 1370 uint64_t *res_compatible, 1371 uint64_t *res_postcopy_only) 1372 { 1373 SaveStateEntry *se; 1374 1375 *res_precopy_only = 0; 1376 *res_compatible = 0; 1377 *res_postcopy_only = 0; 1378 1379 1380 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1381 if (!se->ops || !se->ops->save_live_pending) { 1382 continue; 1383 } 1384 if (se->ops && se->ops->is_active) { 1385 if (!se->ops->is_active(se->opaque)) { 1386 continue; 1387 } 1388 } 1389 se->ops->save_live_pending(f, se->opaque, threshold_size, 1390 res_precopy_only, res_compatible, 1391 res_postcopy_only); 1392 } 1393 } 1394 1395 void qemu_savevm_state_cleanup(void) 1396 { 1397 SaveStateEntry *se; 1398 Error *local_err = NULL; 1399 1400 if (precopy_notify(PRECOPY_NOTIFY_CLEANUP, &local_err)) { 1401 error_report_err(local_err); 1402 } 1403 1404 trace_savevm_state_cleanup(); 1405 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1406 if (se->ops && se->ops->save_cleanup) { 1407 se->ops->save_cleanup(se->opaque); 1408 } 1409 } 1410 } 1411 1412 static int qemu_savevm_state(QEMUFile *f, Error **errp) 1413 { 1414 int ret; 1415 MigrationState *ms = migrate_get_current(); 1416 MigrationStatus status; 1417 1418 if (migration_is_setup_or_active(ms->state) || 1419 ms->state == MIGRATION_STATUS_CANCELLING || 1420 ms->state == MIGRATION_STATUS_COLO) { 1421 error_setg(errp, QERR_MIGRATION_ACTIVE); 1422 return -EINVAL; 1423 } 1424 1425 if (migrate_use_block()) { 1426 error_setg(errp, "Block migration and snapshots are incompatible"); 1427 return -EINVAL; 1428 } 1429 1430 migrate_init(ms); 1431 ms->to_dst_file = f; 1432 1433 qemu_mutex_unlock_iothread(); 1434 qemu_savevm_state_header(f); 1435 qemu_savevm_state_setup(f); 1436 qemu_mutex_lock_iothread(); 1437 1438 while (qemu_file_get_error(f) == 0) { 1439 if (qemu_savevm_state_iterate(f, false) > 0) { 1440 break; 1441 } 1442 } 1443 1444 ret = qemu_file_get_error(f); 1445 if (ret == 0) { 1446 qemu_savevm_state_complete_precopy(f, false, false); 1447 ret = qemu_file_get_error(f); 1448 } 1449 qemu_savevm_state_cleanup(); 1450 if (ret != 0) { 1451 error_setg_errno(errp, -ret, "Error while writing VM state"); 1452 } 1453 1454 if (ret != 0) { 1455 status = MIGRATION_STATUS_FAILED; 1456 } else { 1457 status = MIGRATION_STATUS_COMPLETED; 1458 } 1459 migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status); 1460 1461 /* f is outer parameter, it should not stay in global migration state after 1462 * this function finished */ 1463 ms->to_dst_file = NULL; 1464 1465 return ret; 1466 } 1467 1468 void qemu_savevm_live_state(QEMUFile *f) 1469 { 1470 /* save QEMU_VM_SECTION_END section */ 1471 qemu_savevm_state_complete_precopy(f, true, false); 1472 qemu_put_byte(f, QEMU_VM_EOF); 1473 } 1474 1475 int qemu_save_device_state(QEMUFile *f) 1476 { 1477 SaveStateEntry *se; 1478 1479 if (!migration_in_colo_state()) { 1480 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1481 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1482 } 1483 cpu_synchronize_all_states(); 1484 1485 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1486 int ret; 1487 1488 if (se->is_ram) { 1489 continue; 1490 } 1491 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1492 continue; 1493 } 1494 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1495 continue; 1496 } 1497 1498 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1499 1500 ret = vmstate_save(f, se, NULL); 1501 if (ret) { 1502 return ret; 1503 } 1504 1505 save_section_footer(f, se); 1506 } 1507 1508 qemu_put_byte(f, QEMU_VM_EOF); 1509 1510 return qemu_file_get_error(f); 1511 } 1512 1513 static SaveStateEntry *find_se(const char *idstr, int instance_id) 1514 { 1515 SaveStateEntry *se; 1516 1517 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1518 if (!strcmp(se->idstr, idstr) && 1519 (instance_id == se->instance_id || 1520 instance_id == se->alias_id)) 1521 return se; 1522 /* Migrating from an older version? */ 1523 if (strstr(se->idstr, idstr) && se->compat) { 1524 if (!strcmp(se->compat->idstr, idstr) && 1525 (instance_id == se->compat->instance_id || 1526 instance_id == se->alias_id)) 1527 return se; 1528 } 1529 } 1530 return NULL; 1531 } 1532 1533 enum LoadVMExitCodes { 1534 /* Allow a command to quit all layers of nested loadvm loops */ 1535 LOADVM_QUIT = 1, 1536 }; 1537 1538 /* ------ incoming postcopy messages ------ */ 1539 /* 'advise' arrives before any transfers just to tell us that a postcopy 1540 * *might* happen - it might be skipped if precopy transferred everything 1541 * quickly. 1542 */ 1543 static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis, 1544 uint16_t len) 1545 { 1546 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1547 uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps; 1548 Error *local_err = NULL; 1549 1550 trace_loadvm_postcopy_handle_advise(); 1551 if (ps != POSTCOPY_INCOMING_NONE) { 1552 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps); 1553 return -1; 1554 } 1555 1556 switch (len) { 1557 case 0: 1558 if (migrate_postcopy_ram()) { 1559 error_report("RAM postcopy is enabled but have 0 byte advise"); 1560 return -EINVAL; 1561 } 1562 return 0; 1563 case 8 + 8: 1564 if (!migrate_postcopy_ram()) { 1565 error_report("RAM postcopy is disabled but have 16 byte advise"); 1566 return -EINVAL; 1567 } 1568 break; 1569 default: 1570 error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len); 1571 return -EINVAL; 1572 } 1573 1574 if (!postcopy_ram_supported_by_host(mis)) { 1575 postcopy_state_set(POSTCOPY_INCOMING_NONE); 1576 return -1; 1577 } 1578 1579 remote_pagesize_summary = qemu_get_be64(mis->from_src_file); 1580 local_pagesize_summary = ram_pagesize_summary(); 1581 1582 if (remote_pagesize_summary != local_pagesize_summary) { 1583 /* 1584 * This detects two potential causes of mismatch: 1585 * a) A mismatch in host page sizes 1586 * Some combinations of mismatch are probably possible but it gets 1587 * a bit more complicated. In particular we need to place whole 1588 * host pages on the dest at once, and we need to ensure that we 1589 * handle dirtying to make sure we never end up sending part of 1590 * a hostpage on it's own. 1591 * b) The use of different huge page sizes on source/destination 1592 * a more fine grain test is performed during RAM block migration 1593 * but this test here causes a nice early clear failure, and 1594 * also fails when passed to an older qemu that doesn't 1595 * do huge pages. 1596 */ 1597 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64 1598 " d=%" PRIx64 ")", 1599 remote_pagesize_summary, local_pagesize_summary); 1600 return -1; 1601 } 1602 1603 remote_tps = qemu_get_be64(mis->from_src_file); 1604 if (remote_tps != qemu_target_page_size()) { 1605 /* 1606 * Again, some differences could be dealt with, but for now keep it 1607 * simple. 1608 */ 1609 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)", 1610 (int)remote_tps, qemu_target_page_size()); 1611 return -1; 1612 } 1613 1614 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) { 1615 error_report_err(local_err); 1616 return -1; 1617 } 1618 1619 if (ram_postcopy_incoming_init(mis)) { 1620 return -1; 1621 } 1622 1623 postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1624 1625 return 0; 1626 } 1627 1628 /* After postcopy we will be told to throw some pages away since they're 1629 * dirty and will have to be demand fetched. Must happen before CPU is 1630 * started. 1631 * There can be 0..many of these messages, each encoding multiple pages. 1632 */ 1633 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis, 1634 uint16_t len) 1635 { 1636 int tmp; 1637 char ramid[256]; 1638 PostcopyState ps = postcopy_state_get(); 1639 1640 trace_loadvm_postcopy_ram_handle_discard(); 1641 1642 switch (ps) { 1643 case POSTCOPY_INCOMING_ADVISE: 1644 /* 1st discard */ 1645 tmp = postcopy_ram_prepare_discard(mis); 1646 if (tmp) { 1647 return tmp; 1648 } 1649 break; 1650 1651 case POSTCOPY_INCOMING_DISCARD: 1652 /* Expected state */ 1653 break; 1654 1655 default: 1656 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)", 1657 ps); 1658 return -1; 1659 } 1660 /* We're expecting a 1661 * Version (0) 1662 * a RAM ID string (length byte, name, 0 term) 1663 * then at least 1 16 byte chunk 1664 */ 1665 if (len < (1 + 1 + 1 + 1 + 2 * 8)) { 1666 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1667 return -1; 1668 } 1669 1670 tmp = qemu_get_byte(mis->from_src_file); 1671 if (tmp != postcopy_ram_discard_version) { 1672 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp); 1673 return -1; 1674 } 1675 1676 if (!qemu_get_counted_string(mis->from_src_file, ramid)) { 1677 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID"); 1678 return -1; 1679 } 1680 tmp = qemu_get_byte(mis->from_src_file); 1681 if (tmp != 0) { 1682 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp); 1683 return -1; 1684 } 1685 1686 len -= 3 + strlen(ramid); 1687 if (len % 16) { 1688 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1689 return -1; 1690 } 1691 trace_loadvm_postcopy_ram_handle_discard_header(ramid, len); 1692 while (len) { 1693 uint64_t start_addr, block_length; 1694 start_addr = qemu_get_be64(mis->from_src_file); 1695 block_length = qemu_get_be64(mis->from_src_file); 1696 1697 len -= 16; 1698 int ret = ram_discard_range(ramid, start_addr, block_length); 1699 if (ret) { 1700 return ret; 1701 } 1702 } 1703 trace_loadvm_postcopy_ram_handle_discard_end(); 1704 1705 return 0; 1706 } 1707 1708 /* 1709 * Triggered by a postcopy_listen command; this thread takes over reading 1710 * the input stream, leaving the main thread free to carry on loading the rest 1711 * of the device state (from RAM). 1712 * (TODO:This could do with being in a postcopy file - but there again it's 1713 * just another input loop, not that postcopy specific) 1714 */ 1715 static void *postcopy_ram_listen_thread(void *opaque) 1716 { 1717 MigrationIncomingState *mis = migration_incoming_get_current(); 1718 QEMUFile *f = mis->from_src_file; 1719 int load_res; 1720 1721 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 1722 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1723 qemu_sem_post(&mis->listen_thread_sem); 1724 trace_postcopy_ram_listen_thread_start(); 1725 1726 rcu_register_thread(); 1727 /* 1728 * Because we're a thread and not a coroutine we can't yield 1729 * in qemu_file, and thus we must be blocking now. 1730 */ 1731 qemu_file_set_blocking(f, true); 1732 load_res = qemu_loadvm_state_main(f, mis); 1733 1734 /* 1735 * This is tricky, but, mis->from_src_file can change after it 1736 * returns, when postcopy recovery happened. In the future, we may 1737 * want a wrapper for the QEMUFile handle. 1738 */ 1739 f = mis->from_src_file; 1740 1741 /* And non-blocking again so we don't block in any cleanup */ 1742 qemu_file_set_blocking(f, false); 1743 1744 trace_postcopy_ram_listen_thread_exit(); 1745 if (load_res < 0) { 1746 error_report("%s: loadvm failed: %d", __func__, load_res); 1747 qemu_file_set_error(f, load_res); 1748 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1749 MIGRATION_STATUS_FAILED); 1750 } else { 1751 /* 1752 * This looks good, but it's possible that the device loading in the 1753 * main thread hasn't finished yet, and so we might not be in 'RUN' 1754 * state yet; wait for the end of the main thread. 1755 */ 1756 qemu_event_wait(&mis->main_thread_load_event); 1757 } 1758 postcopy_ram_incoming_cleanup(mis); 1759 1760 if (load_res < 0) { 1761 /* 1762 * If something went wrong then we have a bad state so exit; 1763 * depending how far we got it might be possible at this point 1764 * to leave the guest running and fire MCEs for pages that never 1765 * arrived as a desperate recovery step. 1766 */ 1767 rcu_unregister_thread(); 1768 exit(EXIT_FAILURE); 1769 } 1770 1771 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1772 MIGRATION_STATUS_COMPLETED); 1773 /* 1774 * If everything has worked fine, then the main thread has waited 1775 * for us to start, and we're the last use of the mis. 1776 * (If something broke then qemu will have to exit anyway since it's 1777 * got a bad migration state). 1778 */ 1779 migration_incoming_state_destroy(); 1780 qemu_loadvm_state_cleanup(); 1781 1782 rcu_unregister_thread(); 1783 mis->have_listen_thread = false; 1784 return NULL; 1785 } 1786 1787 /* After this message we must be able to immediately receive postcopy data */ 1788 static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) 1789 { 1790 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING); 1791 trace_loadvm_postcopy_handle_listen(); 1792 Error *local_err = NULL; 1793 1794 if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) { 1795 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps); 1796 return -1; 1797 } 1798 if (ps == POSTCOPY_INCOMING_ADVISE) { 1799 /* 1800 * A rare case, we entered listen without having to do any discards, 1801 * so do the setup that's normally done at the time of the 1st discard. 1802 */ 1803 if (migrate_postcopy_ram()) { 1804 postcopy_ram_prepare_discard(mis); 1805 } 1806 } 1807 1808 /* 1809 * Sensitise RAM - can now generate requests for blocks that don't exist 1810 * However, at this point the CPU shouldn't be running, and the IO 1811 * shouldn't be doing anything yet so don't actually expect requests 1812 */ 1813 if (migrate_postcopy_ram()) { 1814 if (postcopy_ram_enable_notify(mis)) { 1815 postcopy_ram_incoming_cleanup(mis); 1816 return -1; 1817 } 1818 } 1819 1820 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) { 1821 error_report_err(local_err); 1822 return -1; 1823 } 1824 1825 if (mis->have_listen_thread) { 1826 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread"); 1827 return -1; 1828 } 1829 1830 mis->have_listen_thread = true; 1831 /* Start up the listening thread and wait for it to signal ready */ 1832 qemu_sem_init(&mis->listen_thread_sem, 0); 1833 qemu_thread_create(&mis->listen_thread, "postcopy/listen", 1834 postcopy_ram_listen_thread, NULL, 1835 QEMU_THREAD_DETACHED); 1836 qemu_sem_wait(&mis->listen_thread_sem); 1837 qemu_sem_destroy(&mis->listen_thread_sem); 1838 1839 return 0; 1840 } 1841 1842 1843 typedef struct { 1844 QEMUBH *bh; 1845 } HandleRunBhData; 1846 1847 static void loadvm_postcopy_handle_run_bh(void *opaque) 1848 { 1849 Error *local_err = NULL; 1850 HandleRunBhData *data = opaque; 1851 MigrationIncomingState *mis = migration_incoming_get_current(); 1852 1853 /* TODO we should move all of this lot into postcopy_ram.c or a shared code 1854 * in migration.c 1855 */ 1856 cpu_synchronize_all_post_init(); 1857 1858 qemu_announce_self(&mis->announce_timer, migrate_announce_params()); 1859 1860 /* Make sure all file formats flush their mutable metadata. 1861 * If we get an error here, just don't restart the VM yet. */ 1862 bdrv_invalidate_cache_all(&local_err); 1863 if (local_err) { 1864 error_report_err(local_err); 1865 local_err = NULL; 1866 autostart = false; 1867 } 1868 1869 trace_loadvm_postcopy_handle_run_cpu_sync(); 1870 1871 trace_loadvm_postcopy_handle_run_vmstart(); 1872 1873 dirty_bitmap_mig_before_vm_start(); 1874 1875 if (autostart) { 1876 /* Hold onto your hats, starting the CPU */ 1877 vm_start(); 1878 } else { 1879 /* leave it paused and let management decide when to start the CPU */ 1880 runstate_set(RUN_STATE_PAUSED); 1881 } 1882 1883 qemu_bh_delete(data->bh); 1884 g_free(data); 1885 } 1886 1887 /* After all discards we can start running and asking for pages */ 1888 static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) 1889 { 1890 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING); 1891 HandleRunBhData *data; 1892 1893 trace_loadvm_postcopy_handle_run(); 1894 if (ps != POSTCOPY_INCOMING_LISTENING) { 1895 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps); 1896 return -1; 1897 } 1898 1899 data = g_new(HandleRunBhData, 1); 1900 data->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, data); 1901 qemu_bh_schedule(data->bh); 1902 1903 /* We need to finish reading the stream from the package 1904 * and also stop reading anything more from the stream that loaded the 1905 * package (since it's now being read by the listener thread). 1906 * LOADVM_QUIT will quit all the layers of nested loadvm loops. 1907 */ 1908 return LOADVM_QUIT; 1909 } 1910 1911 static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis) 1912 { 1913 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) { 1914 error_report("%s: illegal resume received", __func__); 1915 /* Don't fail the load, only for this. */ 1916 return 0; 1917 } 1918 1919 /* 1920 * This means source VM is ready to resume the postcopy migration. 1921 * It's time to switch state and release the fault thread to 1922 * continue service page faults. 1923 */ 1924 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER, 1925 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1926 qemu_sem_post(&mis->postcopy_pause_sem_fault); 1927 1928 trace_loadvm_postcopy_handle_resume(); 1929 1930 /* Tell source that "we are ready" */ 1931 migrate_send_rp_resume_ack(mis, MIGRATION_RESUME_ACK_VALUE); 1932 1933 return 0; 1934 } 1935 1936 /** 1937 * Immediately following this command is a blob of data containing an embedded 1938 * chunk of migration stream; read it and load it. 1939 * 1940 * @mis: Incoming state 1941 * @length: Length of packaged data to read 1942 * 1943 * Returns: Negative values on error 1944 * 1945 */ 1946 static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis) 1947 { 1948 int ret; 1949 size_t length; 1950 QIOChannelBuffer *bioc; 1951 1952 length = qemu_get_be32(mis->from_src_file); 1953 trace_loadvm_handle_cmd_packaged(length); 1954 1955 if (length > MAX_VM_CMD_PACKAGED_SIZE) { 1956 error_report("Unreasonably large packaged state: %zu", length); 1957 return -1; 1958 } 1959 1960 bioc = qio_channel_buffer_new(length); 1961 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-loadvm-buffer"); 1962 ret = qemu_get_buffer(mis->from_src_file, 1963 bioc->data, 1964 length); 1965 if (ret != length) { 1966 object_unref(OBJECT(bioc)); 1967 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu", 1968 ret, length); 1969 return (ret < 0) ? ret : -EAGAIN; 1970 } 1971 bioc->usage += length; 1972 trace_loadvm_handle_cmd_packaged_received(ret); 1973 1974 QEMUFile *packf = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); 1975 1976 ret = qemu_loadvm_state_main(packf, mis); 1977 trace_loadvm_handle_cmd_packaged_main(ret); 1978 qemu_fclose(packf); 1979 object_unref(OBJECT(bioc)); 1980 1981 return ret; 1982 } 1983 1984 /* 1985 * Handle request that source requests for recved_bitmap on 1986 * destination. Payload format: 1987 * 1988 * len (1 byte) + ramblock_name (<255 bytes) 1989 */ 1990 static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis, 1991 uint16_t len) 1992 { 1993 QEMUFile *file = mis->from_src_file; 1994 RAMBlock *rb; 1995 char block_name[256]; 1996 size_t cnt; 1997 1998 cnt = qemu_get_counted_string(file, block_name); 1999 if (!cnt) { 2000 error_report("%s: failed to read block name", __func__); 2001 return -EINVAL; 2002 } 2003 2004 /* Validate before using the data */ 2005 if (qemu_file_get_error(file)) { 2006 return qemu_file_get_error(file); 2007 } 2008 2009 if (len != cnt + 1) { 2010 error_report("%s: invalid payload length (%d)", __func__, len); 2011 return -EINVAL; 2012 } 2013 2014 rb = qemu_ram_block_by_name(block_name); 2015 if (!rb) { 2016 error_report("%s: block '%s' not found", __func__, block_name); 2017 return -EINVAL; 2018 } 2019 2020 migrate_send_rp_recv_bitmap(mis, block_name); 2021 2022 trace_loadvm_handle_recv_bitmap(block_name); 2023 2024 return 0; 2025 } 2026 2027 static int loadvm_process_enable_colo(MigrationIncomingState *mis) 2028 { 2029 migration_incoming_enable_colo(); 2030 return colo_init_ram_cache(); 2031 } 2032 2033 /* 2034 * Process an incoming 'QEMU_VM_COMMAND' 2035 * 0 just a normal return 2036 * LOADVM_QUIT All good, but exit the loop 2037 * <0 Error 2038 */ 2039 static int loadvm_process_command(QEMUFile *f) 2040 { 2041 MigrationIncomingState *mis = migration_incoming_get_current(); 2042 uint16_t cmd; 2043 uint16_t len; 2044 uint32_t tmp32; 2045 2046 cmd = qemu_get_be16(f); 2047 len = qemu_get_be16(f); 2048 2049 /* Check validity before continue processing of cmds */ 2050 if (qemu_file_get_error(f)) { 2051 return qemu_file_get_error(f); 2052 } 2053 2054 trace_loadvm_process_command(cmd, len); 2055 if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) { 2056 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len); 2057 return -EINVAL; 2058 } 2059 2060 if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) { 2061 error_report("%s received with bad length - expecting %zu, got %d", 2062 mig_cmd_args[cmd].name, 2063 (size_t)mig_cmd_args[cmd].len, len); 2064 return -ERANGE; 2065 } 2066 2067 switch (cmd) { 2068 case MIG_CMD_OPEN_RETURN_PATH: 2069 if (mis->to_src_file) { 2070 error_report("CMD_OPEN_RETURN_PATH called when RP already open"); 2071 /* Not really a problem, so don't give up */ 2072 return 0; 2073 } 2074 mis->to_src_file = qemu_file_get_return_path(f); 2075 if (!mis->to_src_file) { 2076 error_report("CMD_OPEN_RETURN_PATH failed"); 2077 return -1; 2078 } 2079 break; 2080 2081 case MIG_CMD_PING: 2082 tmp32 = qemu_get_be32(f); 2083 trace_loadvm_process_command_ping(tmp32); 2084 if (!mis->to_src_file) { 2085 error_report("CMD_PING (0x%x) received with no return path", 2086 tmp32); 2087 return -1; 2088 } 2089 migrate_send_rp_pong(mis, tmp32); 2090 break; 2091 2092 case MIG_CMD_PACKAGED: 2093 return loadvm_handle_cmd_packaged(mis); 2094 2095 case MIG_CMD_POSTCOPY_ADVISE: 2096 return loadvm_postcopy_handle_advise(mis, len); 2097 2098 case MIG_CMD_POSTCOPY_LISTEN: 2099 return loadvm_postcopy_handle_listen(mis); 2100 2101 case MIG_CMD_POSTCOPY_RUN: 2102 return loadvm_postcopy_handle_run(mis); 2103 2104 case MIG_CMD_POSTCOPY_RAM_DISCARD: 2105 return loadvm_postcopy_ram_handle_discard(mis, len); 2106 2107 case MIG_CMD_POSTCOPY_RESUME: 2108 return loadvm_postcopy_handle_resume(mis); 2109 2110 case MIG_CMD_RECV_BITMAP: 2111 return loadvm_handle_recv_bitmap(mis, len); 2112 2113 case MIG_CMD_ENABLE_COLO: 2114 return loadvm_process_enable_colo(mis); 2115 } 2116 2117 return 0; 2118 } 2119 2120 /* 2121 * Read a footer off the wire and check that it matches the expected section 2122 * 2123 * Returns: true if the footer was good 2124 * false if there is a problem (and calls error_report to say why) 2125 */ 2126 static bool check_section_footer(QEMUFile *f, SaveStateEntry *se) 2127 { 2128 int ret; 2129 uint8_t read_mark; 2130 uint32_t read_section_id; 2131 2132 if (!migrate_get_current()->send_section_footer) { 2133 /* No footer to check */ 2134 return true; 2135 } 2136 2137 read_mark = qemu_get_byte(f); 2138 2139 ret = qemu_file_get_error(f); 2140 if (ret) { 2141 error_report("%s: Read section footer failed: %d", 2142 __func__, ret); 2143 return false; 2144 } 2145 2146 if (read_mark != QEMU_VM_SECTION_FOOTER) { 2147 error_report("Missing section footer for %s", se->idstr); 2148 return false; 2149 } 2150 2151 read_section_id = qemu_get_be32(f); 2152 if (read_section_id != se->load_section_id) { 2153 error_report("Mismatched section id in footer for %s -" 2154 " read 0x%x expected 0x%x", 2155 se->idstr, read_section_id, se->load_section_id); 2156 return false; 2157 } 2158 2159 /* All good */ 2160 return true; 2161 } 2162 2163 static int 2164 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis) 2165 { 2166 uint32_t instance_id, version_id, section_id; 2167 SaveStateEntry *se; 2168 char idstr[256]; 2169 int ret; 2170 2171 /* Read section start */ 2172 section_id = qemu_get_be32(f); 2173 if (!qemu_get_counted_string(f, idstr)) { 2174 error_report("Unable to read ID string for section %u", 2175 section_id); 2176 return -EINVAL; 2177 } 2178 instance_id = qemu_get_be32(f); 2179 version_id = qemu_get_be32(f); 2180 2181 ret = qemu_file_get_error(f); 2182 if (ret) { 2183 error_report("%s: Failed to read instance/version ID: %d", 2184 __func__, ret); 2185 return ret; 2186 } 2187 2188 trace_qemu_loadvm_state_section_startfull(section_id, idstr, 2189 instance_id, version_id); 2190 /* Find savevm section */ 2191 se = find_se(idstr, instance_id); 2192 if (se == NULL) { 2193 error_report("Unknown savevm section or instance '%s' %d. " 2194 "Make sure that your current VM setup matches your " 2195 "saved VM setup, including any hotplugged devices", 2196 idstr, instance_id); 2197 return -EINVAL; 2198 } 2199 2200 /* Validate version */ 2201 if (version_id > se->version_id) { 2202 error_report("savevm: unsupported version %d for '%s' v%d", 2203 version_id, idstr, se->version_id); 2204 return -EINVAL; 2205 } 2206 se->load_version_id = version_id; 2207 se->load_section_id = section_id; 2208 2209 /* Validate if it is a device's state */ 2210 if (xen_enabled() && se->is_ram) { 2211 error_report("loadvm: %s RAM loading not allowed on Xen", idstr); 2212 return -EINVAL; 2213 } 2214 2215 ret = vmstate_load(f, se); 2216 if (ret < 0) { 2217 error_report("error while loading state for instance 0x%x of" 2218 " device '%s'", instance_id, idstr); 2219 return ret; 2220 } 2221 if (!check_section_footer(f, se)) { 2222 return -EINVAL; 2223 } 2224 2225 return 0; 2226 } 2227 2228 static int 2229 qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis) 2230 { 2231 uint32_t section_id; 2232 SaveStateEntry *se; 2233 int ret; 2234 2235 section_id = qemu_get_be32(f); 2236 2237 ret = qemu_file_get_error(f); 2238 if (ret) { 2239 error_report("%s: Failed to read section ID: %d", 2240 __func__, ret); 2241 return ret; 2242 } 2243 2244 trace_qemu_loadvm_state_section_partend(section_id); 2245 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2246 if (se->load_section_id == section_id) { 2247 break; 2248 } 2249 } 2250 if (se == NULL) { 2251 error_report("Unknown savevm section %d", section_id); 2252 return -EINVAL; 2253 } 2254 2255 ret = vmstate_load(f, se); 2256 if (ret < 0) { 2257 error_report("error while loading state section id %d(%s)", 2258 section_id, se->idstr); 2259 return ret; 2260 } 2261 if (!check_section_footer(f, se)) { 2262 return -EINVAL; 2263 } 2264 2265 return 0; 2266 } 2267 2268 static int qemu_loadvm_state_header(QEMUFile *f) 2269 { 2270 unsigned int v; 2271 int ret; 2272 2273 v = qemu_get_be32(f); 2274 if (v != QEMU_VM_FILE_MAGIC) { 2275 error_report("Not a migration stream"); 2276 return -EINVAL; 2277 } 2278 2279 v = qemu_get_be32(f); 2280 if (v == QEMU_VM_FILE_VERSION_COMPAT) { 2281 error_report("SaveVM v2 format is obsolete and don't work anymore"); 2282 return -ENOTSUP; 2283 } 2284 if (v != QEMU_VM_FILE_VERSION) { 2285 error_report("Unsupported migration stream version"); 2286 return -ENOTSUP; 2287 } 2288 2289 if (migrate_get_current()->send_configuration) { 2290 if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) { 2291 error_report("Configuration section missing"); 2292 qemu_loadvm_state_cleanup(); 2293 return -EINVAL; 2294 } 2295 ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0); 2296 2297 if (ret) { 2298 qemu_loadvm_state_cleanup(); 2299 return ret; 2300 } 2301 } 2302 return 0; 2303 } 2304 2305 static int qemu_loadvm_state_setup(QEMUFile *f) 2306 { 2307 SaveStateEntry *se; 2308 int ret; 2309 2310 trace_loadvm_state_setup(); 2311 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2312 if (!se->ops || !se->ops->load_setup) { 2313 continue; 2314 } 2315 if (se->ops && se->ops->is_active) { 2316 if (!se->ops->is_active(se->opaque)) { 2317 continue; 2318 } 2319 } 2320 2321 ret = se->ops->load_setup(f, se->opaque); 2322 if (ret < 0) { 2323 qemu_file_set_error(f, ret); 2324 error_report("Load state of device %s failed", se->idstr); 2325 return ret; 2326 } 2327 } 2328 return 0; 2329 } 2330 2331 void qemu_loadvm_state_cleanup(void) 2332 { 2333 SaveStateEntry *se; 2334 2335 trace_loadvm_state_cleanup(); 2336 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2337 if (se->ops && se->ops->load_cleanup) { 2338 se->ops->load_cleanup(se->opaque); 2339 } 2340 } 2341 } 2342 2343 /* Return true if we should continue the migration, or false. */ 2344 static bool postcopy_pause_incoming(MigrationIncomingState *mis) 2345 { 2346 trace_postcopy_pause_incoming(); 2347 2348 /* Clear the triggered bit to allow one recovery */ 2349 mis->postcopy_recover_triggered = false; 2350 2351 assert(mis->from_src_file); 2352 qemu_file_shutdown(mis->from_src_file); 2353 qemu_fclose(mis->from_src_file); 2354 mis->from_src_file = NULL; 2355 2356 assert(mis->to_src_file); 2357 qemu_file_shutdown(mis->to_src_file); 2358 qemu_mutex_lock(&mis->rp_mutex); 2359 qemu_fclose(mis->to_src_file); 2360 mis->to_src_file = NULL; 2361 qemu_mutex_unlock(&mis->rp_mutex); 2362 2363 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2364 MIGRATION_STATUS_POSTCOPY_PAUSED); 2365 2366 /* Notify the fault thread for the invalidated file handle */ 2367 postcopy_fault_thread_notify(mis); 2368 2369 error_report("Detected IO failure for postcopy. " 2370 "Migration paused."); 2371 2372 while (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) { 2373 qemu_sem_wait(&mis->postcopy_pause_sem_dst); 2374 } 2375 2376 trace_postcopy_pause_incoming_continued(); 2377 2378 return true; 2379 } 2380 2381 int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis) 2382 { 2383 uint8_t section_type; 2384 int ret = 0; 2385 2386 retry: 2387 while (true) { 2388 section_type = qemu_get_byte(f); 2389 2390 if (qemu_file_get_error(f)) { 2391 ret = qemu_file_get_error(f); 2392 break; 2393 } 2394 2395 trace_qemu_loadvm_state_section(section_type); 2396 switch (section_type) { 2397 case QEMU_VM_SECTION_START: 2398 case QEMU_VM_SECTION_FULL: 2399 ret = qemu_loadvm_section_start_full(f, mis); 2400 if (ret < 0) { 2401 goto out; 2402 } 2403 break; 2404 case QEMU_VM_SECTION_PART: 2405 case QEMU_VM_SECTION_END: 2406 ret = qemu_loadvm_section_part_end(f, mis); 2407 if (ret < 0) { 2408 goto out; 2409 } 2410 break; 2411 case QEMU_VM_COMMAND: 2412 ret = loadvm_process_command(f); 2413 trace_qemu_loadvm_state_section_command(ret); 2414 if ((ret < 0) || (ret & LOADVM_QUIT)) { 2415 goto out; 2416 } 2417 break; 2418 case QEMU_VM_EOF: 2419 /* This is the end of migration */ 2420 goto out; 2421 default: 2422 error_report("Unknown savevm section type %d", section_type); 2423 ret = -EINVAL; 2424 goto out; 2425 } 2426 } 2427 2428 out: 2429 if (ret < 0) { 2430 qemu_file_set_error(f, ret); 2431 2432 /* 2433 * If we are during an active postcopy, then we pause instead 2434 * of bail out to at least keep the VM's dirty data. Note 2435 * that POSTCOPY_INCOMING_LISTENING stage is still not enough, 2436 * during which we're still receiving device states and we 2437 * still haven't yet started the VM on destination. 2438 */ 2439 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING && 2440 postcopy_pause_incoming(mis)) { 2441 /* Reset f to point to the newly created channel */ 2442 f = mis->from_src_file; 2443 goto retry; 2444 } 2445 } 2446 return ret; 2447 } 2448 2449 int qemu_loadvm_state(QEMUFile *f) 2450 { 2451 MigrationIncomingState *mis = migration_incoming_get_current(); 2452 Error *local_err = NULL; 2453 int ret; 2454 2455 if (qemu_savevm_state_blocked(&local_err)) { 2456 error_report_err(local_err); 2457 return -EINVAL; 2458 } 2459 2460 ret = qemu_loadvm_state_header(f); 2461 if (ret) { 2462 return ret; 2463 } 2464 2465 if (qemu_loadvm_state_setup(f) != 0) { 2466 return -EINVAL; 2467 } 2468 2469 cpu_synchronize_all_pre_loadvm(); 2470 2471 ret = qemu_loadvm_state_main(f, mis); 2472 qemu_event_set(&mis->main_thread_load_event); 2473 2474 trace_qemu_loadvm_state_post_main(ret); 2475 2476 if (mis->have_listen_thread) { 2477 /* Listen thread still going, can't clean up yet */ 2478 return ret; 2479 } 2480 2481 if (ret == 0) { 2482 ret = qemu_file_get_error(f); 2483 } 2484 2485 /* 2486 * Try to read in the VMDESC section as well, so that dumping tools that 2487 * intercept our migration stream have the chance to see it. 2488 */ 2489 2490 /* We've got to be careful; if we don't read the data and just shut the fd 2491 * then the sender can error if we close while it's still sending. 2492 * We also mustn't read data that isn't there; some transports (RDMA) 2493 * will stall waiting for that data when the source has already closed. 2494 */ 2495 if (ret == 0 && should_send_vmdesc()) { 2496 uint8_t *buf; 2497 uint32_t size; 2498 uint8_t section_type = qemu_get_byte(f); 2499 2500 if (section_type != QEMU_VM_VMDESCRIPTION) { 2501 error_report("Expected vmdescription section, but got %d", 2502 section_type); 2503 /* 2504 * It doesn't seem worth failing at this point since 2505 * we apparently have an otherwise valid VM state 2506 */ 2507 } else { 2508 buf = g_malloc(0x1000); 2509 size = qemu_get_be32(f); 2510 2511 while (size > 0) { 2512 uint32_t read_chunk = MIN(size, 0x1000); 2513 qemu_get_buffer(f, buf, read_chunk); 2514 size -= read_chunk; 2515 } 2516 g_free(buf); 2517 } 2518 } 2519 2520 qemu_loadvm_state_cleanup(); 2521 cpu_synchronize_all_post_init(); 2522 2523 return ret; 2524 } 2525 2526 int qemu_load_device_state(QEMUFile *f) 2527 { 2528 MigrationIncomingState *mis = migration_incoming_get_current(); 2529 int ret; 2530 2531 /* Load QEMU_VM_SECTION_FULL section */ 2532 ret = qemu_loadvm_state_main(f, mis); 2533 if (ret < 0) { 2534 error_report("Failed to load device state: %d", ret); 2535 return ret; 2536 } 2537 2538 cpu_synchronize_all_post_init(); 2539 return 0; 2540 } 2541 2542 int save_snapshot(const char *name, Error **errp) 2543 { 2544 BlockDriverState *bs, *bs1; 2545 QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1; 2546 int ret = -1; 2547 QEMUFile *f; 2548 int saved_vm_running; 2549 uint64_t vm_state_size; 2550 qemu_timeval tv; 2551 struct tm tm; 2552 AioContext *aio_context; 2553 2554 if (migration_is_blocked(errp)) { 2555 return ret; 2556 } 2557 2558 if (!replay_can_snapshot()) { 2559 error_setg(errp, "Record/replay does not allow making snapshot " 2560 "right now. Try once more later."); 2561 return ret; 2562 } 2563 2564 if (!bdrv_all_can_snapshot(&bs)) { 2565 error_setg(errp, "Device '%s' is writable but does not support " 2566 "snapshots", bdrv_get_device_name(bs)); 2567 return ret; 2568 } 2569 2570 /* Delete old snapshots of the same name */ 2571 if (name) { 2572 ret = bdrv_all_delete_snapshot(name, &bs1, errp); 2573 if (ret < 0) { 2574 error_prepend(errp, "Error while deleting snapshot on device " 2575 "'%s': ", bdrv_get_device_name(bs1)); 2576 return ret; 2577 } 2578 } 2579 2580 bs = bdrv_all_find_vmstate_bs(); 2581 if (bs == NULL) { 2582 error_setg(errp, "No block device can accept snapshots"); 2583 return ret; 2584 } 2585 aio_context = bdrv_get_aio_context(bs); 2586 2587 saved_vm_running = runstate_is_running(); 2588 2589 ret = global_state_store(); 2590 if (ret) { 2591 error_setg(errp, "Error saving global state"); 2592 return ret; 2593 } 2594 vm_stop(RUN_STATE_SAVE_VM); 2595 2596 bdrv_drain_all_begin(); 2597 2598 aio_context_acquire(aio_context); 2599 2600 memset(sn, 0, sizeof(*sn)); 2601 2602 /* fill auxiliary fields */ 2603 qemu_gettimeofday(&tv); 2604 sn->date_sec = tv.tv_sec; 2605 sn->date_nsec = tv.tv_usec * 1000; 2606 sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 2607 2608 if (name) { 2609 ret = bdrv_snapshot_find(bs, old_sn, name); 2610 if (ret >= 0) { 2611 pstrcpy(sn->name, sizeof(sn->name), old_sn->name); 2612 pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str); 2613 } else { 2614 pstrcpy(sn->name, sizeof(sn->name), name); 2615 } 2616 } else { 2617 /* cast below needed for OpenBSD where tv_sec is still 'long' */ 2618 localtime_r((const time_t *)&tv.tv_sec, &tm); 2619 strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm); 2620 } 2621 2622 /* save the VM state */ 2623 f = qemu_fopen_bdrv(bs, 1); 2624 if (!f) { 2625 error_setg(errp, "Could not open VM state file"); 2626 goto the_end; 2627 } 2628 ret = qemu_savevm_state(f, errp); 2629 vm_state_size = qemu_ftell(f); 2630 qemu_fclose(f); 2631 if (ret < 0) { 2632 goto the_end; 2633 } 2634 2635 /* The bdrv_all_create_snapshot() call that follows acquires the AioContext 2636 * for itself. BDRV_POLL_WHILE() does not support nested locking because 2637 * it only releases the lock once. Therefore synchronous I/O will deadlock 2638 * unless we release the AioContext before bdrv_all_create_snapshot(). 2639 */ 2640 aio_context_release(aio_context); 2641 aio_context = NULL; 2642 2643 ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs); 2644 if (ret < 0) { 2645 error_setg(errp, "Error while creating snapshot on '%s'", 2646 bdrv_get_device_name(bs)); 2647 goto the_end; 2648 } 2649 2650 ret = 0; 2651 2652 the_end: 2653 if (aio_context) { 2654 aio_context_release(aio_context); 2655 } 2656 2657 bdrv_drain_all_end(); 2658 2659 if (saved_vm_running) { 2660 vm_start(); 2661 } 2662 return ret; 2663 } 2664 2665 void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live, 2666 Error **errp) 2667 { 2668 QEMUFile *f; 2669 QIOChannelFile *ioc; 2670 int saved_vm_running; 2671 int ret; 2672 2673 if (!has_live) { 2674 /* live default to true so old version of Xen tool stack can have a 2675 * successfull live migration */ 2676 live = true; 2677 } 2678 2679 saved_vm_running = runstate_is_running(); 2680 vm_stop(RUN_STATE_SAVE_VM); 2681 global_state_store_running(); 2682 2683 ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT, 0660, errp); 2684 if (!ioc) { 2685 goto the_end; 2686 } 2687 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-save-state"); 2688 f = qemu_fopen_channel_output(QIO_CHANNEL(ioc)); 2689 object_unref(OBJECT(ioc)); 2690 ret = qemu_save_device_state(f); 2691 if (ret < 0 || qemu_fclose(f) < 0) { 2692 error_setg(errp, QERR_IO_ERROR); 2693 } else { 2694 /* libxl calls the QMP command "stop" before calling 2695 * "xen-save-devices-state" and in case of migration failure, libxl 2696 * would call "cont". 2697 * So call bdrv_inactivate_all (release locks) here to let the other 2698 * side of the migration take controle of the images. 2699 */ 2700 if (live && !saved_vm_running) { 2701 ret = bdrv_inactivate_all(); 2702 if (ret) { 2703 error_setg(errp, "%s: bdrv_inactivate_all() failed (%d)", 2704 __func__, ret); 2705 } 2706 } 2707 } 2708 2709 the_end: 2710 if (saved_vm_running) { 2711 vm_start(); 2712 } 2713 } 2714 2715 void qmp_xen_load_devices_state(const char *filename, Error **errp) 2716 { 2717 QEMUFile *f; 2718 QIOChannelFile *ioc; 2719 int ret; 2720 2721 /* Guest must be paused before loading the device state; the RAM state 2722 * will already have been loaded by xc 2723 */ 2724 if (runstate_is_running()) { 2725 error_setg(errp, "Cannot update device state while vm is running"); 2726 return; 2727 } 2728 vm_stop(RUN_STATE_RESTORE_VM); 2729 2730 ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0, errp); 2731 if (!ioc) { 2732 return; 2733 } 2734 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-load-state"); 2735 f = qemu_fopen_channel_input(QIO_CHANNEL(ioc)); 2736 object_unref(OBJECT(ioc)); 2737 2738 ret = qemu_loadvm_state(f); 2739 qemu_fclose(f); 2740 if (ret < 0) { 2741 error_setg(errp, QERR_IO_ERROR); 2742 } 2743 migration_incoming_state_destroy(); 2744 } 2745 2746 int load_snapshot(const char *name, Error **errp) 2747 { 2748 BlockDriverState *bs, *bs_vm_state; 2749 QEMUSnapshotInfo sn; 2750 QEMUFile *f; 2751 int ret; 2752 AioContext *aio_context; 2753 MigrationIncomingState *mis = migration_incoming_get_current(); 2754 2755 if (!replay_can_snapshot()) { 2756 error_setg(errp, "Record/replay does not allow loading snapshot " 2757 "right now. Try once more later."); 2758 return -EINVAL; 2759 } 2760 2761 if (!bdrv_all_can_snapshot(&bs)) { 2762 error_setg(errp, 2763 "Device '%s' is writable but does not support snapshots", 2764 bdrv_get_device_name(bs)); 2765 return -ENOTSUP; 2766 } 2767 ret = bdrv_all_find_snapshot(name, &bs); 2768 if (ret < 0) { 2769 error_setg(errp, 2770 "Device '%s' does not have the requested snapshot '%s'", 2771 bdrv_get_device_name(bs), name); 2772 return ret; 2773 } 2774 2775 bs_vm_state = bdrv_all_find_vmstate_bs(); 2776 if (!bs_vm_state) { 2777 error_setg(errp, "No block device supports snapshots"); 2778 return -ENOTSUP; 2779 } 2780 aio_context = bdrv_get_aio_context(bs_vm_state); 2781 2782 /* Don't even try to load empty VM states */ 2783 aio_context_acquire(aio_context); 2784 ret = bdrv_snapshot_find(bs_vm_state, &sn, name); 2785 aio_context_release(aio_context); 2786 if (ret < 0) { 2787 return ret; 2788 } else if (sn.vm_state_size == 0) { 2789 error_setg(errp, "This is a disk-only snapshot. Revert to it " 2790 " offline using qemu-img"); 2791 return -EINVAL; 2792 } 2793 2794 /* Flush all IO requests so they don't interfere with the new state. */ 2795 bdrv_drain_all_begin(); 2796 2797 ret = bdrv_all_goto_snapshot(name, &bs, errp); 2798 if (ret < 0) { 2799 error_prepend(errp, "Could not load snapshot '%s' on '%s': ", 2800 name, bdrv_get_device_name(bs)); 2801 goto err_drain; 2802 } 2803 2804 /* restore the VM state */ 2805 f = qemu_fopen_bdrv(bs_vm_state, 0); 2806 if (!f) { 2807 error_setg(errp, "Could not open VM state file"); 2808 ret = -EINVAL; 2809 goto err_drain; 2810 } 2811 2812 qemu_system_reset(SHUTDOWN_CAUSE_NONE); 2813 mis->from_src_file = f; 2814 2815 aio_context_acquire(aio_context); 2816 ret = qemu_loadvm_state(f); 2817 migration_incoming_state_destroy(); 2818 aio_context_release(aio_context); 2819 2820 bdrv_drain_all_end(); 2821 2822 if (ret < 0) { 2823 error_setg(errp, "Error %d while loading VM state", ret); 2824 return ret; 2825 } 2826 2827 return 0; 2828 2829 err_drain: 2830 bdrv_drain_all_end(); 2831 return ret; 2832 } 2833 2834 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev) 2835 { 2836 qemu_ram_set_idstr(mr->ram_block, 2837 memory_region_name(mr), dev); 2838 qemu_ram_set_migratable(mr->ram_block); 2839 } 2840 2841 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev) 2842 { 2843 qemu_ram_unset_idstr(mr->ram_block); 2844 qemu_ram_unset_migratable(mr->ram_block); 2845 } 2846 2847 void vmstate_register_ram_global(MemoryRegion *mr) 2848 { 2849 vmstate_register_ram(mr, NULL); 2850 } 2851 2852 bool vmstate_check_only_migratable(const VMStateDescription *vmsd) 2853 { 2854 /* check needed if --only-migratable is specified */ 2855 if (!only_migratable) { 2856 return true; 2857 } 2858 2859 return !(vmsd && vmsd->unmigratable); 2860 } 2861