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 "net/net.h" 32 #include "migration.h" 33 #include "migration/snapshot.h" 34 #include "migration/vmstate.h" 35 #include "migration/misc.h" 36 #include "migration/register.h" 37 #include "migration/global_state.h" 38 #include "migration/channel-block.h" 39 #include "ram.h" 40 #include "qemu-file.h" 41 #include "savevm.h" 42 #include "postcopy-ram.h" 43 #include "qapi/error.h" 44 #include "qapi/qapi-commands-migration.h" 45 #include "qapi/qmp/json-writer.h" 46 #include "qapi/clone-visitor.h" 47 #include "qapi/qapi-builtin-visit.h" 48 #include "qapi/qmp/qerror.h" 49 #include "qemu/error-report.h" 50 #include "sysemu/cpus.h" 51 #include "exec/memory.h" 52 #include "exec/target_page.h" 53 #include "trace.h" 54 #include "qemu/iov.h" 55 #include "qemu/main-loop.h" 56 #include "block/snapshot.h" 57 #include "qemu/cutils.h" 58 #include "io/channel-buffer.h" 59 #include "io/channel-file.h" 60 #include "sysemu/replay.h" 61 #include "sysemu/runstate.h" 62 #include "sysemu/sysemu.h" 63 #include "sysemu/xen.h" 64 #include "migration/colo.h" 65 #include "qemu/bitmap.h" 66 #include "net/announce.h" 67 #include "qemu/yank.h" 68 #include "yank_functions.h" 69 70 const unsigned int postcopy_ram_discard_version; 71 72 /* Subcommands for QEMU_VM_COMMAND */ 73 enum qemu_vm_cmd { 74 MIG_CMD_INVALID = 0, /* Must be 0 */ 75 MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */ 76 MIG_CMD_PING, /* Request a PONG on the RP */ 77 78 MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just 79 warn we might want to do PC */ 80 MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming 81 pages as it's running. */ 82 MIG_CMD_POSTCOPY_RUN, /* Start execution */ 83 84 MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that 85 were previously sent during 86 precopy but are dirty. */ 87 MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */ 88 MIG_CMD_ENABLE_COLO, /* Enable COLO */ 89 MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */ 90 MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */ 91 MIG_CMD_MAX 92 }; 93 94 #define MAX_VM_CMD_PACKAGED_SIZE UINT32_MAX 95 static struct mig_cmd_args { 96 ssize_t len; /* -1 = variable */ 97 const char *name; 98 } mig_cmd_args[] = { 99 [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" }, 100 [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" }, 101 [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" }, 102 [MIG_CMD_POSTCOPY_ADVISE] = { .len = -1, .name = "POSTCOPY_ADVISE" }, 103 [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" }, 104 [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" }, 105 [MIG_CMD_POSTCOPY_RAM_DISCARD] = { 106 .len = -1, .name = "POSTCOPY_RAM_DISCARD" }, 107 [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" }, 108 [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" }, 109 [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" }, 110 [MIG_CMD_MAX] = { .len = -1, .name = "MAX" }, 111 }; 112 113 /* Note for MIG_CMD_POSTCOPY_ADVISE: 114 * The format of arguments is depending on postcopy mode: 115 * - postcopy RAM only 116 * uint64_t host page size 117 * uint64_t taget page size 118 * 119 * - postcopy RAM and postcopy dirty bitmaps 120 * format is the same as for postcopy RAM only 121 * 122 * - postcopy dirty bitmaps only 123 * Nothing. Command length field is 0. 124 * 125 * Be careful: adding a new postcopy entity with some other parameters should 126 * not break format self-description ability. Good way is to introduce some 127 * generic extendable format with an exception for two old entities. 128 */ 129 130 /***********************************************************/ 131 /* savevm/loadvm support */ 132 133 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable) 134 { 135 if (is_writable) { 136 return qemu_file_new_output(QIO_CHANNEL(qio_channel_block_new(bs))); 137 } else { 138 return qemu_file_new_input(QIO_CHANNEL(qio_channel_block_new(bs))); 139 } 140 } 141 142 143 /* QEMUFile timer support. 144 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c 145 */ 146 147 void timer_put(QEMUFile *f, QEMUTimer *ts) 148 { 149 uint64_t expire_time; 150 151 expire_time = timer_expire_time_ns(ts); 152 qemu_put_be64(f, expire_time); 153 } 154 155 void timer_get(QEMUFile *f, QEMUTimer *ts) 156 { 157 uint64_t expire_time; 158 159 expire_time = qemu_get_be64(f); 160 if (expire_time != -1) { 161 timer_mod_ns(ts, expire_time); 162 } else { 163 timer_del(ts); 164 } 165 } 166 167 168 /* VMState timer support. 169 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c 170 */ 171 172 static int get_timer(QEMUFile *f, void *pv, size_t size, 173 const VMStateField *field) 174 { 175 QEMUTimer *v = pv; 176 timer_get(f, v); 177 return 0; 178 } 179 180 static int put_timer(QEMUFile *f, void *pv, size_t size, 181 const VMStateField *field, JSONWriter *vmdesc) 182 { 183 QEMUTimer *v = pv; 184 timer_put(f, v); 185 186 return 0; 187 } 188 189 const VMStateInfo vmstate_info_timer = { 190 .name = "timer", 191 .get = get_timer, 192 .put = put_timer, 193 }; 194 195 196 typedef struct CompatEntry { 197 char idstr[256]; 198 int instance_id; 199 } CompatEntry; 200 201 typedef struct SaveStateEntry { 202 QTAILQ_ENTRY(SaveStateEntry) entry; 203 char idstr[256]; 204 uint32_t instance_id; 205 int alias_id; 206 int version_id; 207 /* version id read from the stream */ 208 int load_version_id; 209 int section_id; 210 /* section id read from the stream */ 211 int load_section_id; 212 const SaveVMHandlers *ops; 213 const VMStateDescription *vmsd; 214 void *opaque; 215 CompatEntry *compat; 216 int is_ram; 217 } SaveStateEntry; 218 219 typedef struct SaveState { 220 QTAILQ_HEAD(, SaveStateEntry) handlers; 221 SaveStateEntry *handler_pri_head[MIG_PRI_MAX + 1]; 222 int global_section_id; 223 uint32_t len; 224 const char *name; 225 uint32_t target_page_bits; 226 uint32_t caps_count; 227 MigrationCapability *capabilities; 228 QemuUUID uuid; 229 } SaveState; 230 231 static SaveState savevm_state = { 232 .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers), 233 .handler_pri_head = { [MIG_PRI_DEFAULT ... MIG_PRI_MAX] = NULL }, 234 .global_section_id = 0, 235 }; 236 237 static bool should_validate_capability(int capability) 238 { 239 assert(capability >= 0 && capability < MIGRATION_CAPABILITY__MAX); 240 /* Validate only new capabilities to keep compatibility. */ 241 switch (capability) { 242 case MIGRATION_CAPABILITY_X_IGNORE_SHARED: 243 return true; 244 default: 245 return false; 246 } 247 } 248 249 static uint32_t get_validatable_capabilities_count(void) 250 { 251 MigrationState *s = migrate_get_current(); 252 uint32_t result = 0; 253 int i; 254 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 255 if (should_validate_capability(i) && s->enabled_capabilities[i]) { 256 result++; 257 } 258 } 259 return result; 260 } 261 262 static int configuration_pre_save(void *opaque) 263 { 264 SaveState *state = opaque; 265 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 266 MigrationState *s = migrate_get_current(); 267 int i, j; 268 269 state->len = strlen(current_name); 270 state->name = current_name; 271 state->target_page_bits = qemu_target_page_bits(); 272 273 state->caps_count = get_validatable_capabilities_count(); 274 state->capabilities = g_renew(MigrationCapability, state->capabilities, 275 state->caps_count); 276 for (i = j = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 277 if (should_validate_capability(i) && s->enabled_capabilities[i]) { 278 state->capabilities[j++] = i; 279 } 280 } 281 state->uuid = qemu_uuid; 282 283 return 0; 284 } 285 286 static int configuration_post_save(void *opaque) 287 { 288 SaveState *state = opaque; 289 290 g_free(state->capabilities); 291 state->capabilities = NULL; 292 state->caps_count = 0; 293 return 0; 294 } 295 296 static int configuration_pre_load(void *opaque) 297 { 298 SaveState *state = opaque; 299 300 /* If there is no target-page-bits subsection it means the source 301 * predates the variable-target-page-bits support and is using the 302 * minimum possible value for this CPU. 303 */ 304 state->target_page_bits = qemu_target_page_bits_min(); 305 return 0; 306 } 307 308 static bool configuration_validate_capabilities(SaveState *state) 309 { 310 bool ret = true; 311 MigrationState *s = migrate_get_current(); 312 unsigned long *source_caps_bm; 313 int i; 314 315 source_caps_bm = bitmap_new(MIGRATION_CAPABILITY__MAX); 316 for (i = 0; i < state->caps_count; i++) { 317 MigrationCapability capability = state->capabilities[i]; 318 set_bit(capability, source_caps_bm); 319 } 320 321 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 322 bool source_state, target_state; 323 if (!should_validate_capability(i)) { 324 continue; 325 } 326 source_state = test_bit(i, source_caps_bm); 327 target_state = s->enabled_capabilities[i]; 328 if (source_state != target_state) { 329 error_report("Capability %s is %s, but received capability is %s", 330 MigrationCapability_str(i), 331 target_state ? "on" : "off", 332 source_state ? "on" : "off"); 333 ret = false; 334 /* Don't break here to report all failed capabilities */ 335 } 336 } 337 338 g_free(source_caps_bm); 339 return ret; 340 } 341 342 static int configuration_post_load(void *opaque, int version_id) 343 { 344 SaveState *state = opaque; 345 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 346 int ret = 0; 347 348 if (strncmp(state->name, current_name, state->len) != 0) { 349 error_report("Machine type received is '%.*s' and local is '%s'", 350 (int) state->len, state->name, current_name); 351 ret = -EINVAL; 352 goto out; 353 } 354 355 if (state->target_page_bits != qemu_target_page_bits()) { 356 error_report("Received TARGET_PAGE_BITS is %d but local is %d", 357 state->target_page_bits, qemu_target_page_bits()); 358 ret = -EINVAL; 359 goto out; 360 } 361 362 if (!configuration_validate_capabilities(state)) { 363 ret = -EINVAL; 364 goto out; 365 } 366 367 out: 368 g_free((void *)state->name); 369 state->name = NULL; 370 state->len = 0; 371 g_free(state->capabilities); 372 state->capabilities = NULL; 373 state->caps_count = 0; 374 375 return ret; 376 } 377 378 static int get_capability(QEMUFile *f, void *pv, size_t size, 379 const VMStateField *field) 380 { 381 MigrationCapability *capability = pv; 382 char capability_str[UINT8_MAX + 1]; 383 uint8_t len; 384 int i; 385 386 len = qemu_get_byte(f); 387 qemu_get_buffer(f, (uint8_t *)capability_str, len); 388 capability_str[len] = '\0'; 389 for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { 390 if (!strcmp(MigrationCapability_str(i), capability_str)) { 391 *capability = i; 392 return 0; 393 } 394 } 395 error_report("Received unknown capability %s", capability_str); 396 return -EINVAL; 397 } 398 399 static int put_capability(QEMUFile *f, void *pv, size_t size, 400 const VMStateField *field, JSONWriter *vmdesc) 401 { 402 MigrationCapability *capability = pv; 403 const char *capability_str = MigrationCapability_str(*capability); 404 size_t len = strlen(capability_str); 405 assert(len <= UINT8_MAX); 406 407 qemu_put_byte(f, len); 408 qemu_put_buffer(f, (uint8_t *)capability_str, len); 409 return 0; 410 } 411 412 static const VMStateInfo vmstate_info_capability = { 413 .name = "capability", 414 .get = get_capability, 415 .put = put_capability, 416 }; 417 418 /* The target-page-bits subsection is present only if the 419 * target page size is not the same as the default (ie the 420 * minimum page size for a variable-page-size guest CPU). 421 * If it is present then it contains the actual target page 422 * bits for the machine, and migration will fail if the 423 * two ends don't agree about it. 424 */ 425 static bool vmstate_target_page_bits_needed(void *opaque) 426 { 427 return qemu_target_page_bits() 428 > qemu_target_page_bits_min(); 429 } 430 431 static const VMStateDescription vmstate_target_page_bits = { 432 .name = "configuration/target-page-bits", 433 .version_id = 1, 434 .minimum_version_id = 1, 435 .needed = vmstate_target_page_bits_needed, 436 .fields = (VMStateField[]) { 437 VMSTATE_UINT32(target_page_bits, SaveState), 438 VMSTATE_END_OF_LIST() 439 } 440 }; 441 442 static bool vmstate_capabilites_needed(void *opaque) 443 { 444 return get_validatable_capabilities_count() > 0; 445 } 446 447 static const VMStateDescription vmstate_capabilites = { 448 .name = "configuration/capabilities", 449 .version_id = 1, 450 .minimum_version_id = 1, 451 .needed = vmstate_capabilites_needed, 452 .fields = (VMStateField[]) { 453 VMSTATE_UINT32_V(caps_count, SaveState, 1), 454 VMSTATE_VARRAY_UINT32_ALLOC(capabilities, SaveState, caps_count, 1, 455 vmstate_info_capability, 456 MigrationCapability), 457 VMSTATE_END_OF_LIST() 458 } 459 }; 460 461 static bool vmstate_uuid_needed(void *opaque) 462 { 463 return qemu_uuid_set && migrate_validate_uuid(); 464 } 465 466 static int vmstate_uuid_post_load(void *opaque, int version_id) 467 { 468 SaveState *state = opaque; 469 char uuid_src[UUID_FMT_LEN + 1]; 470 char uuid_dst[UUID_FMT_LEN + 1]; 471 472 if (!qemu_uuid_set) { 473 /* 474 * It's warning because user might not know UUID in some cases, 475 * e.g. load an old snapshot 476 */ 477 qemu_uuid_unparse(&state->uuid, uuid_src); 478 warn_report("UUID is received %s, but local uuid isn't set", 479 uuid_src); 480 return 0; 481 } 482 if (!qemu_uuid_is_equal(&state->uuid, &qemu_uuid)) { 483 qemu_uuid_unparse(&state->uuid, uuid_src); 484 qemu_uuid_unparse(&qemu_uuid, uuid_dst); 485 error_report("UUID received is %s and local is %s", uuid_src, uuid_dst); 486 return -EINVAL; 487 } 488 return 0; 489 } 490 491 static const VMStateDescription vmstate_uuid = { 492 .name = "configuration/uuid", 493 .version_id = 1, 494 .minimum_version_id = 1, 495 .needed = vmstate_uuid_needed, 496 .post_load = vmstate_uuid_post_load, 497 .fields = (VMStateField[]) { 498 VMSTATE_UINT8_ARRAY_V(uuid.data, SaveState, sizeof(QemuUUID), 1), 499 VMSTATE_END_OF_LIST() 500 } 501 }; 502 503 static const VMStateDescription vmstate_configuration = { 504 .name = "configuration", 505 .version_id = 1, 506 .pre_load = configuration_pre_load, 507 .post_load = configuration_post_load, 508 .pre_save = configuration_pre_save, 509 .post_save = configuration_post_save, 510 .fields = (VMStateField[]) { 511 VMSTATE_UINT32(len, SaveState), 512 VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len), 513 VMSTATE_END_OF_LIST() 514 }, 515 .subsections = (const VMStateDescription *[]) { 516 &vmstate_target_page_bits, 517 &vmstate_capabilites, 518 &vmstate_uuid, 519 NULL 520 } 521 }; 522 523 static void dump_vmstate_vmsd(FILE *out_file, 524 const VMStateDescription *vmsd, int indent, 525 bool is_subsection); 526 527 static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field, 528 int indent) 529 { 530 fprintf(out_file, "%*s{\n", indent, ""); 531 indent += 2; 532 fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name); 533 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 534 field->version_id); 535 fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "", 536 field->field_exists ? "true" : "false"); 537 fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size); 538 if (field->vmsd != NULL) { 539 fprintf(out_file, ",\n"); 540 dump_vmstate_vmsd(out_file, field->vmsd, indent, false); 541 } 542 fprintf(out_file, "\n%*s}", indent - 2, ""); 543 } 544 545 static void dump_vmstate_vmss(FILE *out_file, 546 const VMStateDescription **subsection, 547 int indent) 548 { 549 if (*subsection != NULL) { 550 dump_vmstate_vmsd(out_file, *subsection, indent, true); 551 } 552 } 553 554 static void dump_vmstate_vmsd(FILE *out_file, 555 const VMStateDescription *vmsd, int indent, 556 bool is_subsection) 557 { 558 if (is_subsection) { 559 fprintf(out_file, "%*s{\n", indent, ""); 560 } else { 561 fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description"); 562 } 563 indent += 2; 564 fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name); 565 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 566 vmsd->version_id); 567 fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "", 568 vmsd->minimum_version_id); 569 if (vmsd->fields != NULL) { 570 const VMStateField *field = vmsd->fields; 571 bool first; 572 573 fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, ""); 574 first = true; 575 while (field->name != NULL) { 576 if (field->flags & VMS_MUST_EXIST) { 577 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */ 578 field++; 579 continue; 580 } 581 if (!first) { 582 fprintf(out_file, ",\n"); 583 } 584 dump_vmstate_vmsf(out_file, field, indent + 2); 585 field++; 586 first = false; 587 } 588 fprintf(out_file, "\n%*s]", indent, ""); 589 } 590 if (vmsd->subsections != NULL) { 591 const VMStateDescription **subsection = vmsd->subsections; 592 bool first; 593 594 fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, ""); 595 first = true; 596 while (*subsection != NULL) { 597 if (!first) { 598 fprintf(out_file, ",\n"); 599 } 600 dump_vmstate_vmss(out_file, subsection, indent + 2); 601 subsection++; 602 first = false; 603 } 604 fprintf(out_file, "\n%*s]", indent, ""); 605 } 606 fprintf(out_file, "\n%*s}", indent - 2, ""); 607 } 608 609 static void dump_machine_type(FILE *out_file) 610 { 611 MachineClass *mc; 612 613 mc = MACHINE_GET_CLASS(current_machine); 614 615 fprintf(out_file, " \"vmschkmachine\": {\n"); 616 fprintf(out_file, " \"Name\": \"%s\"\n", mc->name); 617 fprintf(out_file, " },\n"); 618 } 619 620 void dump_vmstate_json_to_file(FILE *out_file) 621 { 622 GSList *list, *elt; 623 bool first; 624 625 fprintf(out_file, "{\n"); 626 dump_machine_type(out_file); 627 628 first = true; 629 list = object_class_get_list(TYPE_DEVICE, true); 630 for (elt = list; elt; elt = elt->next) { 631 DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data, 632 TYPE_DEVICE); 633 const char *name; 634 int indent = 2; 635 636 if (!dc->vmsd) { 637 continue; 638 } 639 640 if (!first) { 641 fprintf(out_file, ",\n"); 642 } 643 name = object_class_get_name(OBJECT_CLASS(dc)); 644 fprintf(out_file, "%*s\"%s\": {\n", indent, "", name); 645 indent += 2; 646 fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name); 647 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 648 dc->vmsd->version_id); 649 fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "", 650 dc->vmsd->minimum_version_id); 651 652 dump_vmstate_vmsd(out_file, dc->vmsd, indent, false); 653 654 fprintf(out_file, "\n%*s}", indent - 2, ""); 655 first = false; 656 } 657 fprintf(out_file, "\n}\n"); 658 fclose(out_file); 659 g_slist_free(list); 660 } 661 662 static uint32_t calculate_new_instance_id(const char *idstr) 663 { 664 SaveStateEntry *se; 665 uint32_t instance_id = 0; 666 667 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 668 if (strcmp(idstr, se->idstr) == 0 669 && instance_id <= se->instance_id) { 670 instance_id = se->instance_id + 1; 671 } 672 } 673 /* Make sure we never loop over without being noticed */ 674 assert(instance_id != VMSTATE_INSTANCE_ID_ANY); 675 return instance_id; 676 } 677 678 static int calculate_compat_instance_id(const char *idstr) 679 { 680 SaveStateEntry *se; 681 int instance_id = 0; 682 683 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 684 if (!se->compat) { 685 continue; 686 } 687 688 if (strcmp(idstr, se->compat->idstr) == 0 689 && instance_id <= se->compat->instance_id) { 690 instance_id = se->compat->instance_id + 1; 691 } 692 } 693 return instance_id; 694 } 695 696 static inline MigrationPriority save_state_priority(SaveStateEntry *se) 697 { 698 if (se->vmsd) { 699 return se->vmsd->priority; 700 } 701 return MIG_PRI_DEFAULT; 702 } 703 704 static void savevm_state_handler_insert(SaveStateEntry *nse) 705 { 706 MigrationPriority priority = save_state_priority(nse); 707 SaveStateEntry *se; 708 int i; 709 710 assert(priority <= MIG_PRI_MAX); 711 712 for (i = priority - 1; i >= 0; i--) { 713 se = savevm_state.handler_pri_head[i]; 714 if (se != NULL) { 715 assert(save_state_priority(se) < priority); 716 break; 717 } 718 } 719 720 if (i >= 0) { 721 QTAILQ_INSERT_BEFORE(se, nse, entry); 722 } else { 723 QTAILQ_INSERT_TAIL(&savevm_state.handlers, nse, entry); 724 } 725 726 if (savevm_state.handler_pri_head[priority] == NULL) { 727 savevm_state.handler_pri_head[priority] = nse; 728 } 729 } 730 731 static void savevm_state_handler_remove(SaveStateEntry *se) 732 { 733 SaveStateEntry *next; 734 MigrationPriority priority = save_state_priority(se); 735 736 if (se == savevm_state.handler_pri_head[priority]) { 737 next = QTAILQ_NEXT(se, entry); 738 if (next != NULL && save_state_priority(next) == priority) { 739 savevm_state.handler_pri_head[priority] = next; 740 } else { 741 savevm_state.handler_pri_head[priority] = NULL; 742 } 743 } 744 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 745 } 746 747 /* TODO: Individual devices generally have very little idea about the rest 748 of the system, so instance_id should be removed/replaced. 749 Meanwhile pass -1 as instance_id if you do not already have a clearly 750 distinguishing id for all instances of your device class. */ 751 int register_savevm_live(const char *idstr, 752 uint32_t instance_id, 753 int version_id, 754 const SaveVMHandlers *ops, 755 void *opaque) 756 { 757 SaveStateEntry *se; 758 759 se = g_new0(SaveStateEntry, 1); 760 se->version_id = version_id; 761 se->section_id = savevm_state.global_section_id++; 762 se->ops = ops; 763 se->opaque = opaque; 764 se->vmsd = NULL; 765 /* if this is a live_savem then set is_ram */ 766 if (ops->save_setup != NULL) { 767 se->is_ram = 1; 768 } 769 770 pstrcat(se->idstr, sizeof(se->idstr), idstr); 771 772 if (instance_id == VMSTATE_INSTANCE_ID_ANY) { 773 se->instance_id = calculate_new_instance_id(se->idstr); 774 } else { 775 se->instance_id = instance_id; 776 } 777 assert(!se->compat || se->instance_id == 0); 778 savevm_state_handler_insert(se); 779 return 0; 780 } 781 782 void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque) 783 { 784 SaveStateEntry *se, *new_se; 785 char id[256] = ""; 786 787 if (obj) { 788 char *oid = vmstate_if_get_id(obj); 789 if (oid) { 790 pstrcpy(id, sizeof(id), oid); 791 pstrcat(id, sizeof(id), "/"); 792 g_free(oid); 793 } 794 } 795 pstrcat(id, sizeof(id), idstr); 796 797 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 798 if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) { 799 savevm_state_handler_remove(se); 800 g_free(se->compat); 801 g_free(se); 802 } 803 } 804 } 805 806 int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id, 807 const VMStateDescription *vmsd, 808 void *opaque, int alias_id, 809 int required_for_version, 810 Error **errp) 811 { 812 SaveStateEntry *se; 813 814 /* If this triggers, alias support can be dropped for the vmsd. */ 815 assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id); 816 817 se = g_new0(SaveStateEntry, 1); 818 se->version_id = vmsd->version_id; 819 se->section_id = savevm_state.global_section_id++; 820 se->opaque = opaque; 821 se->vmsd = vmsd; 822 se->alias_id = alias_id; 823 824 if (obj) { 825 char *id = vmstate_if_get_id(obj); 826 if (id) { 827 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 828 sizeof(se->idstr)) { 829 error_setg(errp, "Path too long for VMState (%s)", id); 830 g_free(id); 831 g_free(se); 832 833 return -1; 834 } 835 g_free(id); 836 837 se->compat = g_new0(CompatEntry, 1); 838 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name); 839 se->compat->instance_id = instance_id == VMSTATE_INSTANCE_ID_ANY ? 840 calculate_compat_instance_id(vmsd->name) : instance_id; 841 instance_id = VMSTATE_INSTANCE_ID_ANY; 842 } 843 } 844 pstrcat(se->idstr, sizeof(se->idstr), vmsd->name); 845 846 if (instance_id == VMSTATE_INSTANCE_ID_ANY) { 847 se->instance_id = calculate_new_instance_id(se->idstr); 848 } else { 849 se->instance_id = instance_id; 850 } 851 assert(!se->compat || se->instance_id == 0); 852 savevm_state_handler_insert(se); 853 return 0; 854 } 855 856 void vmstate_unregister(VMStateIf *obj, const VMStateDescription *vmsd, 857 void *opaque) 858 { 859 SaveStateEntry *se, *new_se; 860 861 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 862 if (se->vmsd == vmsd && se->opaque == opaque) { 863 savevm_state_handler_remove(se); 864 g_free(se->compat); 865 g_free(se); 866 } 867 } 868 } 869 870 static int vmstate_load(QEMUFile *f, SaveStateEntry *se) 871 { 872 trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 873 if (!se->vmsd) { /* Old style */ 874 return se->ops->load_state(f, se->opaque, se->load_version_id); 875 } 876 return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id); 877 } 878 879 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, 880 JSONWriter *vmdesc) 881 { 882 int64_t old_offset, size; 883 884 old_offset = qemu_file_total_transferred_fast(f); 885 se->ops->save_state(f, se->opaque); 886 size = qemu_file_total_transferred_fast(f) - old_offset; 887 888 if (vmdesc) { 889 json_writer_int64(vmdesc, "size", size); 890 json_writer_start_array(vmdesc, "fields"); 891 json_writer_start_object(vmdesc, NULL); 892 json_writer_str(vmdesc, "name", "data"); 893 json_writer_int64(vmdesc, "size", size); 894 json_writer_str(vmdesc, "type", "buffer"); 895 json_writer_end_object(vmdesc); 896 json_writer_end_array(vmdesc); 897 } 898 } 899 900 static int vmstate_save(QEMUFile *f, SaveStateEntry *se, 901 JSONWriter *vmdesc) 902 { 903 trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 904 if (!se->vmsd) { 905 vmstate_save_old_style(f, se, vmdesc); 906 return 0; 907 } 908 return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc); 909 } 910 911 /* 912 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL) 913 */ 914 static void save_section_header(QEMUFile *f, SaveStateEntry *se, 915 uint8_t section_type) 916 { 917 qemu_put_byte(f, section_type); 918 qemu_put_be32(f, se->section_id); 919 920 if (section_type == QEMU_VM_SECTION_FULL || 921 section_type == QEMU_VM_SECTION_START) { 922 /* ID string */ 923 size_t len = strlen(se->idstr); 924 qemu_put_byte(f, len); 925 qemu_put_buffer(f, (uint8_t *)se->idstr, len); 926 927 qemu_put_be32(f, se->instance_id); 928 qemu_put_be32(f, se->version_id); 929 } 930 } 931 932 /* 933 * Write a footer onto device sections that catches cases misformatted device 934 * sections. 935 */ 936 static void save_section_footer(QEMUFile *f, SaveStateEntry *se) 937 { 938 if (migrate_get_current()->send_section_footer) { 939 qemu_put_byte(f, QEMU_VM_SECTION_FOOTER); 940 qemu_put_be32(f, se->section_id); 941 } 942 } 943 944 /** 945 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the 946 * command and associated data. 947 * 948 * @f: File to send command on 949 * @command: Command type to send 950 * @len: Length of associated data 951 * @data: Data associated with command. 952 */ 953 static void qemu_savevm_command_send(QEMUFile *f, 954 enum qemu_vm_cmd command, 955 uint16_t len, 956 uint8_t *data) 957 { 958 trace_savevm_command_send(command, len); 959 qemu_put_byte(f, QEMU_VM_COMMAND); 960 qemu_put_be16(f, (uint16_t)command); 961 qemu_put_be16(f, len); 962 qemu_put_buffer(f, data, len); 963 qemu_fflush(f); 964 } 965 966 void qemu_savevm_send_colo_enable(QEMUFile *f) 967 { 968 trace_savevm_send_colo_enable(); 969 qemu_savevm_command_send(f, MIG_CMD_ENABLE_COLO, 0, NULL); 970 } 971 972 void qemu_savevm_send_ping(QEMUFile *f, uint32_t value) 973 { 974 uint32_t buf; 975 976 trace_savevm_send_ping(value); 977 buf = cpu_to_be32(value); 978 qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf); 979 } 980 981 void qemu_savevm_send_open_return_path(QEMUFile *f) 982 { 983 trace_savevm_send_open_return_path(); 984 qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL); 985 } 986 987 /* We have a buffer of data to send; we don't want that all to be loaded 988 * by the command itself, so the command contains just the length of the 989 * extra buffer that we then send straight after it. 990 * TODO: Must be a better way to organise that 991 * 992 * Returns: 993 * 0 on success 994 * -ve on error 995 */ 996 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len) 997 { 998 uint32_t tmp; 999 1000 if (len > MAX_VM_CMD_PACKAGED_SIZE) { 1001 error_report("%s: Unreasonably large packaged state: %zu", 1002 __func__, len); 1003 return -1; 1004 } 1005 1006 tmp = cpu_to_be32(len); 1007 1008 trace_qemu_savevm_send_packaged(); 1009 qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp); 1010 1011 qemu_put_buffer(f, buf, len); 1012 1013 return 0; 1014 } 1015 1016 /* Send prior to any postcopy transfer */ 1017 void qemu_savevm_send_postcopy_advise(QEMUFile *f) 1018 { 1019 if (migrate_postcopy_ram()) { 1020 uint64_t tmp[2]; 1021 tmp[0] = cpu_to_be64(ram_pagesize_summary()); 1022 tmp[1] = cpu_to_be64(qemu_target_page_size()); 1023 1024 trace_qemu_savevm_send_postcopy_advise(); 1025 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 1026 16, (uint8_t *)tmp); 1027 } else { 1028 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 0, NULL); 1029 } 1030 } 1031 1032 /* Sent prior to starting the destination running in postcopy, discard pages 1033 * that have already been sent but redirtied on the source. 1034 * CMD_POSTCOPY_RAM_DISCARD consist of: 1035 * byte version (0) 1036 * byte Length of name field (not including 0) 1037 * n x byte RAM block name 1038 * byte 0 terminator (just for safety) 1039 * n x Byte ranges within the named RAMBlock 1040 * be64 Start of the range 1041 * be64 Length 1042 * 1043 * name: RAMBlock name that these entries are part of 1044 * len: Number of page entries 1045 * start_list: 'len' addresses 1046 * length_list: 'len' addresses 1047 * 1048 */ 1049 void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name, 1050 uint16_t len, 1051 uint64_t *start_list, 1052 uint64_t *length_list) 1053 { 1054 uint8_t *buf; 1055 uint16_t tmplen; 1056 uint16_t t; 1057 size_t name_len = strlen(name); 1058 1059 trace_qemu_savevm_send_postcopy_ram_discard(name, len); 1060 assert(name_len < 256); 1061 buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len); 1062 buf[0] = postcopy_ram_discard_version; 1063 buf[1] = name_len; 1064 memcpy(buf + 2, name, name_len); 1065 tmplen = 2 + name_len; 1066 buf[tmplen++] = '\0'; 1067 1068 for (t = 0; t < len; t++) { 1069 stq_be_p(buf + tmplen, start_list[t]); 1070 tmplen += 8; 1071 stq_be_p(buf + tmplen, length_list[t]); 1072 tmplen += 8; 1073 } 1074 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf); 1075 g_free(buf); 1076 } 1077 1078 /* Get the destination into a state where it can receive postcopy data. */ 1079 void qemu_savevm_send_postcopy_listen(QEMUFile *f) 1080 { 1081 trace_savevm_send_postcopy_listen(); 1082 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL); 1083 } 1084 1085 /* Kick the destination into running */ 1086 void qemu_savevm_send_postcopy_run(QEMUFile *f) 1087 { 1088 trace_savevm_send_postcopy_run(); 1089 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL); 1090 } 1091 1092 void qemu_savevm_send_postcopy_resume(QEMUFile *f) 1093 { 1094 trace_savevm_send_postcopy_resume(); 1095 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL); 1096 } 1097 1098 void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name) 1099 { 1100 size_t len; 1101 char buf[256]; 1102 1103 trace_savevm_send_recv_bitmap(block_name); 1104 1105 buf[0] = len = strlen(block_name); 1106 memcpy(buf + 1, block_name, len); 1107 1108 qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf); 1109 } 1110 1111 bool qemu_savevm_state_blocked(Error **errp) 1112 { 1113 SaveStateEntry *se; 1114 1115 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1116 if (se->vmsd && se->vmsd->unmigratable) { 1117 error_setg(errp, "State blocked by non-migratable device '%s'", 1118 se->idstr); 1119 return true; 1120 } 1121 } 1122 return false; 1123 } 1124 1125 void qemu_savevm_non_migratable_list(strList **reasons) 1126 { 1127 SaveStateEntry *se; 1128 1129 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1130 if (se->vmsd && se->vmsd->unmigratable) { 1131 QAPI_LIST_PREPEND(*reasons, 1132 g_strdup_printf("non-migratable device: %s", 1133 se->idstr)); 1134 } 1135 } 1136 } 1137 1138 void qemu_savevm_state_header(QEMUFile *f) 1139 { 1140 trace_savevm_state_header(); 1141 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1142 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1143 1144 if (migrate_get_current()->send_configuration) { 1145 qemu_put_byte(f, QEMU_VM_CONFIGURATION); 1146 vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0); 1147 } 1148 } 1149 1150 bool qemu_savevm_state_guest_unplug_pending(void) 1151 { 1152 SaveStateEntry *se; 1153 1154 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1155 if (se->vmsd && se->vmsd->dev_unplug_pending && 1156 se->vmsd->dev_unplug_pending(se->opaque)) { 1157 return true; 1158 } 1159 } 1160 1161 return false; 1162 } 1163 1164 void qemu_savevm_state_setup(QEMUFile *f) 1165 { 1166 SaveStateEntry *se; 1167 Error *local_err = NULL; 1168 int ret; 1169 1170 trace_savevm_state_setup(); 1171 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1172 if (!se->ops || !se->ops->save_setup) { 1173 continue; 1174 } 1175 if (se->ops->is_active) { 1176 if (!se->ops->is_active(se->opaque)) { 1177 continue; 1178 } 1179 } 1180 save_section_header(f, se, QEMU_VM_SECTION_START); 1181 1182 ret = se->ops->save_setup(f, se->opaque); 1183 save_section_footer(f, se); 1184 if (ret < 0) { 1185 qemu_file_set_error(f, ret); 1186 break; 1187 } 1188 } 1189 1190 if (precopy_notify(PRECOPY_NOTIFY_SETUP, &local_err)) { 1191 error_report_err(local_err); 1192 } 1193 } 1194 1195 int qemu_savevm_state_resume_prepare(MigrationState *s) 1196 { 1197 SaveStateEntry *se; 1198 int ret; 1199 1200 trace_savevm_state_resume_prepare(); 1201 1202 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1203 if (!se->ops || !se->ops->resume_prepare) { 1204 continue; 1205 } 1206 if (se->ops->is_active) { 1207 if (!se->ops->is_active(se->opaque)) { 1208 continue; 1209 } 1210 } 1211 ret = se->ops->resume_prepare(s, se->opaque); 1212 if (ret < 0) { 1213 return ret; 1214 } 1215 } 1216 1217 return 0; 1218 } 1219 1220 /* 1221 * this function has three return values: 1222 * negative: there was one error, and we have -errno. 1223 * 0 : We haven't finished, caller have to go again 1224 * 1 : We have finished, we can go to complete phase 1225 */ 1226 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy) 1227 { 1228 SaveStateEntry *se; 1229 int ret = 1; 1230 1231 trace_savevm_state_iterate(); 1232 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1233 if (!se->ops || !se->ops->save_live_iterate) { 1234 continue; 1235 } 1236 if (se->ops->is_active && 1237 !se->ops->is_active(se->opaque)) { 1238 continue; 1239 } 1240 if (se->ops->is_active_iterate && 1241 !se->ops->is_active_iterate(se->opaque)) { 1242 continue; 1243 } 1244 /* 1245 * In the postcopy phase, any device that doesn't know how to 1246 * do postcopy should have saved it's state in the _complete 1247 * call that's already run, it might get confused if we call 1248 * iterate afterwards. 1249 */ 1250 if (postcopy && 1251 !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) { 1252 continue; 1253 } 1254 if (qemu_file_rate_limit(f)) { 1255 return 0; 1256 } 1257 trace_savevm_section_start(se->idstr, se->section_id); 1258 1259 save_section_header(f, se, QEMU_VM_SECTION_PART); 1260 1261 ret = se->ops->save_live_iterate(f, se->opaque); 1262 trace_savevm_section_end(se->idstr, se->section_id, ret); 1263 save_section_footer(f, se); 1264 1265 if (ret < 0) { 1266 error_report("failed to save SaveStateEntry with id(name): " 1267 "%d(%s): %d", 1268 se->section_id, se->idstr, ret); 1269 qemu_file_set_error(f, ret); 1270 } 1271 if (ret <= 0) { 1272 /* Do not proceed to the next vmstate before this one reported 1273 completion of the current stage. This serializes the migration 1274 and reduces the probability that a faster changing state is 1275 synchronized over and over again. */ 1276 break; 1277 } 1278 } 1279 return ret; 1280 } 1281 1282 static bool should_send_vmdesc(void) 1283 { 1284 MachineState *machine = MACHINE(qdev_get_machine()); 1285 bool in_postcopy = migration_in_postcopy(); 1286 return !machine->suppress_vmdesc && !in_postcopy; 1287 } 1288 1289 /* 1290 * Calls the save_live_complete_postcopy methods 1291 * causing the last few pages to be sent immediately and doing any associated 1292 * cleanup. 1293 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete 1294 * all the other devices, but that happens at the point we switch to postcopy. 1295 */ 1296 void qemu_savevm_state_complete_postcopy(QEMUFile *f) 1297 { 1298 SaveStateEntry *se; 1299 int ret; 1300 1301 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1302 if (!se->ops || !se->ops->save_live_complete_postcopy) { 1303 continue; 1304 } 1305 if (se->ops->is_active) { 1306 if (!se->ops->is_active(se->opaque)) { 1307 continue; 1308 } 1309 } 1310 trace_savevm_section_start(se->idstr, se->section_id); 1311 /* Section type */ 1312 qemu_put_byte(f, QEMU_VM_SECTION_END); 1313 qemu_put_be32(f, se->section_id); 1314 1315 ret = se->ops->save_live_complete_postcopy(f, se->opaque); 1316 trace_savevm_section_end(se->idstr, se->section_id, ret); 1317 save_section_footer(f, se); 1318 if (ret < 0) { 1319 qemu_file_set_error(f, ret); 1320 return; 1321 } 1322 } 1323 1324 qemu_put_byte(f, QEMU_VM_EOF); 1325 qemu_fflush(f); 1326 } 1327 1328 static 1329 int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy) 1330 { 1331 SaveStateEntry *se; 1332 int ret; 1333 1334 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1335 if (!se->ops || 1336 (in_postcopy && se->ops->has_postcopy && 1337 se->ops->has_postcopy(se->opaque)) || 1338 !se->ops->save_live_complete_precopy) { 1339 continue; 1340 } 1341 1342 if (se->ops->is_active) { 1343 if (!se->ops->is_active(se->opaque)) { 1344 continue; 1345 } 1346 } 1347 trace_savevm_section_start(se->idstr, se->section_id); 1348 1349 save_section_header(f, se, QEMU_VM_SECTION_END); 1350 1351 ret = se->ops->save_live_complete_precopy(f, se->opaque); 1352 trace_savevm_section_end(se->idstr, se->section_id, ret); 1353 save_section_footer(f, se); 1354 if (ret < 0) { 1355 qemu_file_set_error(f, ret); 1356 return -1; 1357 } 1358 } 1359 1360 return 0; 1361 } 1362 1363 int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f, 1364 bool in_postcopy, 1365 bool inactivate_disks) 1366 { 1367 g_autoptr(JSONWriter) vmdesc = NULL; 1368 int vmdesc_len; 1369 SaveStateEntry *se; 1370 int ret; 1371 1372 vmdesc = json_writer_new(false); 1373 json_writer_start_object(vmdesc, NULL); 1374 json_writer_int64(vmdesc, "page_size", qemu_target_page_size()); 1375 json_writer_start_array(vmdesc, "devices"); 1376 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1377 1378 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1379 continue; 1380 } 1381 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1382 trace_savevm_section_skip(se->idstr, se->section_id); 1383 continue; 1384 } 1385 1386 trace_savevm_section_start(se->idstr, se->section_id); 1387 1388 json_writer_start_object(vmdesc, NULL); 1389 json_writer_str(vmdesc, "name", se->idstr); 1390 json_writer_int64(vmdesc, "instance_id", se->instance_id); 1391 1392 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1393 ret = vmstate_save(f, se, vmdesc); 1394 if (ret) { 1395 qemu_file_set_error(f, ret); 1396 return ret; 1397 } 1398 trace_savevm_section_end(se->idstr, se->section_id, 0); 1399 save_section_footer(f, se); 1400 1401 json_writer_end_object(vmdesc); 1402 } 1403 1404 if (inactivate_disks) { 1405 /* Inactivate before sending QEMU_VM_EOF so that the 1406 * bdrv_activate_all() on the other end won't fail. */ 1407 ret = bdrv_inactivate_all(); 1408 if (ret) { 1409 error_report("%s: bdrv_inactivate_all() failed (%d)", 1410 __func__, ret); 1411 qemu_file_set_error(f, ret); 1412 return ret; 1413 } 1414 } 1415 if (!in_postcopy) { 1416 /* Postcopy stream will still be going */ 1417 qemu_put_byte(f, QEMU_VM_EOF); 1418 } 1419 1420 json_writer_end_array(vmdesc); 1421 json_writer_end_object(vmdesc); 1422 vmdesc_len = strlen(json_writer_get(vmdesc)); 1423 1424 if (should_send_vmdesc()) { 1425 qemu_put_byte(f, QEMU_VM_VMDESCRIPTION); 1426 qemu_put_be32(f, vmdesc_len); 1427 qemu_put_buffer(f, (uint8_t *)json_writer_get(vmdesc), vmdesc_len); 1428 } 1429 1430 return 0; 1431 } 1432 1433 int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only, 1434 bool inactivate_disks) 1435 { 1436 int ret; 1437 Error *local_err = NULL; 1438 bool in_postcopy = migration_in_postcopy(); 1439 1440 if (precopy_notify(PRECOPY_NOTIFY_COMPLETE, &local_err)) { 1441 error_report_err(local_err); 1442 } 1443 1444 trace_savevm_state_complete_precopy(); 1445 1446 cpu_synchronize_all_states(); 1447 1448 if (!in_postcopy || iterable_only) { 1449 ret = qemu_savevm_state_complete_precopy_iterable(f, in_postcopy); 1450 if (ret) { 1451 return ret; 1452 } 1453 } 1454 1455 if (iterable_only) { 1456 goto flush; 1457 } 1458 1459 ret = qemu_savevm_state_complete_precopy_non_iterable(f, in_postcopy, 1460 inactivate_disks); 1461 if (ret) { 1462 return ret; 1463 } 1464 1465 flush: 1466 qemu_fflush(f); 1467 return 0; 1468 } 1469 1470 /* Give an estimate of the amount left to be transferred, 1471 * the result is split into the amount for units that can and 1472 * for units that can't do postcopy. 1473 */ 1474 void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size, 1475 uint64_t *res_precopy_only, 1476 uint64_t *res_compatible, 1477 uint64_t *res_postcopy_only) 1478 { 1479 SaveStateEntry *se; 1480 1481 *res_precopy_only = 0; 1482 *res_compatible = 0; 1483 *res_postcopy_only = 0; 1484 1485 1486 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1487 if (!se->ops || !se->ops->save_live_pending) { 1488 continue; 1489 } 1490 if (se->ops->is_active) { 1491 if (!se->ops->is_active(se->opaque)) { 1492 continue; 1493 } 1494 } 1495 se->ops->save_live_pending(f, se->opaque, threshold_size, 1496 res_precopy_only, res_compatible, 1497 res_postcopy_only); 1498 } 1499 } 1500 1501 void qemu_savevm_state_cleanup(void) 1502 { 1503 SaveStateEntry *se; 1504 Error *local_err = NULL; 1505 1506 if (precopy_notify(PRECOPY_NOTIFY_CLEANUP, &local_err)) { 1507 error_report_err(local_err); 1508 } 1509 1510 trace_savevm_state_cleanup(); 1511 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1512 if (se->ops && se->ops->save_cleanup) { 1513 se->ops->save_cleanup(se->opaque); 1514 } 1515 } 1516 } 1517 1518 static int qemu_savevm_state(QEMUFile *f, Error **errp) 1519 { 1520 int ret; 1521 MigrationState *ms = migrate_get_current(); 1522 MigrationStatus status; 1523 1524 if (migration_is_running(ms->state)) { 1525 error_setg(errp, QERR_MIGRATION_ACTIVE); 1526 return -EINVAL; 1527 } 1528 1529 if (migrate_use_block()) { 1530 error_setg(errp, "Block migration and snapshots are incompatible"); 1531 return -EINVAL; 1532 } 1533 1534 migrate_init(ms); 1535 memset(&ram_counters, 0, sizeof(ram_counters)); 1536 memset(&compression_counters, 0, sizeof(compression_counters)); 1537 ms->to_dst_file = f; 1538 1539 qemu_mutex_unlock_iothread(); 1540 qemu_savevm_state_header(f); 1541 qemu_savevm_state_setup(f); 1542 qemu_mutex_lock_iothread(); 1543 1544 while (qemu_file_get_error(f) == 0) { 1545 if (qemu_savevm_state_iterate(f, false) > 0) { 1546 break; 1547 } 1548 } 1549 1550 ret = qemu_file_get_error(f); 1551 if (ret == 0) { 1552 qemu_savevm_state_complete_precopy(f, false, false); 1553 ret = qemu_file_get_error(f); 1554 } 1555 qemu_savevm_state_cleanup(); 1556 if (ret != 0) { 1557 error_setg_errno(errp, -ret, "Error while writing VM state"); 1558 } 1559 1560 if (ret != 0) { 1561 status = MIGRATION_STATUS_FAILED; 1562 } else { 1563 status = MIGRATION_STATUS_COMPLETED; 1564 } 1565 migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status); 1566 1567 /* f is outer parameter, it should not stay in global migration state after 1568 * this function finished */ 1569 ms->to_dst_file = NULL; 1570 1571 return ret; 1572 } 1573 1574 void qemu_savevm_live_state(QEMUFile *f) 1575 { 1576 /* save QEMU_VM_SECTION_END section */ 1577 qemu_savevm_state_complete_precopy(f, true, false); 1578 qemu_put_byte(f, QEMU_VM_EOF); 1579 } 1580 1581 int qemu_save_device_state(QEMUFile *f) 1582 { 1583 SaveStateEntry *se; 1584 1585 if (!migration_in_colo_state()) { 1586 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1587 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1588 } 1589 cpu_synchronize_all_states(); 1590 1591 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1592 int ret; 1593 1594 if (se->is_ram) { 1595 continue; 1596 } 1597 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1598 continue; 1599 } 1600 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1601 continue; 1602 } 1603 1604 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1605 1606 ret = vmstate_save(f, se, NULL); 1607 if (ret) { 1608 return ret; 1609 } 1610 1611 save_section_footer(f, se); 1612 } 1613 1614 qemu_put_byte(f, QEMU_VM_EOF); 1615 1616 return qemu_file_get_error(f); 1617 } 1618 1619 static SaveStateEntry *find_se(const char *idstr, uint32_t instance_id) 1620 { 1621 SaveStateEntry *se; 1622 1623 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1624 if (!strcmp(se->idstr, idstr) && 1625 (instance_id == se->instance_id || 1626 instance_id == se->alias_id)) 1627 return se; 1628 /* Migrating from an older version? */ 1629 if (strstr(se->idstr, idstr) && se->compat) { 1630 if (!strcmp(se->compat->idstr, idstr) && 1631 (instance_id == se->compat->instance_id || 1632 instance_id == se->alias_id)) 1633 return se; 1634 } 1635 } 1636 return NULL; 1637 } 1638 1639 enum LoadVMExitCodes { 1640 /* Allow a command to quit all layers of nested loadvm loops */ 1641 LOADVM_QUIT = 1, 1642 }; 1643 1644 /* ------ incoming postcopy messages ------ */ 1645 /* 'advise' arrives before any transfers just to tell us that a postcopy 1646 * *might* happen - it might be skipped if precopy transferred everything 1647 * quickly. 1648 */ 1649 static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis, 1650 uint16_t len) 1651 { 1652 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1653 uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps; 1654 size_t page_size = qemu_target_page_size(); 1655 Error *local_err = NULL; 1656 1657 trace_loadvm_postcopy_handle_advise(); 1658 if (ps != POSTCOPY_INCOMING_NONE) { 1659 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps); 1660 return -1; 1661 } 1662 1663 switch (len) { 1664 case 0: 1665 if (migrate_postcopy_ram()) { 1666 error_report("RAM postcopy is enabled but have 0 byte advise"); 1667 return -EINVAL; 1668 } 1669 return 0; 1670 case 8 + 8: 1671 if (!migrate_postcopy_ram()) { 1672 error_report("RAM postcopy is disabled but have 16 byte advise"); 1673 return -EINVAL; 1674 } 1675 break; 1676 default: 1677 error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len); 1678 return -EINVAL; 1679 } 1680 1681 if (!postcopy_ram_supported_by_host(mis)) { 1682 postcopy_state_set(POSTCOPY_INCOMING_NONE); 1683 return -1; 1684 } 1685 1686 remote_pagesize_summary = qemu_get_be64(mis->from_src_file); 1687 local_pagesize_summary = ram_pagesize_summary(); 1688 1689 if (remote_pagesize_summary != local_pagesize_summary) { 1690 /* 1691 * This detects two potential causes of mismatch: 1692 * a) A mismatch in host page sizes 1693 * Some combinations of mismatch are probably possible but it gets 1694 * a bit more complicated. In particular we need to place whole 1695 * host pages on the dest at once, and we need to ensure that we 1696 * handle dirtying to make sure we never end up sending part of 1697 * a hostpage on it's own. 1698 * b) The use of different huge page sizes on source/destination 1699 * a more fine grain test is performed during RAM block migration 1700 * but this test here causes a nice early clear failure, and 1701 * also fails when passed to an older qemu that doesn't 1702 * do huge pages. 1703 */ 1704 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64 1705 " d=%" PRIx64 ")", 1706 remote_pagesize_summary, local_pagesize_summary); 1707 return -1; 1708 } 1709 1710 remote_tps = qemu_get_be64(mis->from_src_file); 1711 if (remote_tps != page_size) { 1712 /* 1713 * Again, some differences could be dealt with, but for now keep it 1714 * simple. 1715 */ 1716 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)", 1717 (int)remote_tps, page_size); 1718 return -1; 1719 } 1720 1721 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) { 1722 error_report_err(local_err); 1723 return -1; 1724 } 1725 1726 if (ram_postcopy_incoming_init(mis)) { 1727 return -1; 1728 } 1729 1730 return 0; 1731 } 1732 1733 /* After postcopy we will be told to throw some pages away since they're 1734 * dirty and will have to be demand fetched. Must happen before CPU is 1735 * started. 1736 * There can be 0..many of these messages, each encoding multiple pages. 1737 */ 1738 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis, 1739 uint16_t len) 1740 { 1741 int tmp; 1742 char ramid[256]; 1743 PostcopyState ps = postcopy_state_get(); 1744 1745 trace_loadvm_postcopy_ram_handle_discard(); 1746 1747 switch (ps) { 1748 case POSTCOPY_INCOMING_ADVISE: 1749 /* 1st discard */ 1750 tmp = postcopy_ram_prepare_discard(mis); 1751 if (tmp) { 1752 return tmp; 1753 } 1754 break; 1755 1756 case POSTCOPY_INCOMING_DISCARD: 1757 /* Expected state */ 1758 break; 1759 1760 default: 1761 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)", 1762 ps); 1763 return -1; 1764 } 1765 /* We're expecting a 1766 * Version (0) 1767 * a RAM ID string (length byte, name, 0 term) 1768 * then at least 1 16 byte chunk 1769 */ 1770 if (len < (1 + 1 + 1 + 1 + 2 * 8)) { 1771 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1772 return -1; 1773 } 1774 1775 tmp = qemu_get_byte(mis->from_src_file); 1776 if (tmp != postcopy_ram_discard_version) { 1777 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp); 1778 return -1; 1779 } 1780 1781 if (!qemu_get_counted_string(mis->from_src_file, ramid)) { 1782 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID"); 1783 return -1; 1784 } 1785 tmp = qemu_get_byte(mis->from_src_file); 1786 if (tmp != 0) { 1787 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp); 1788 return -1; 1789 } 1790 1791 len -= 3 + strlen(ramid); 1792 if (len % 16) { 1793 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1794 return -1; 1795 } 1796 trace_loadvm_postcopy_ram_handle_discard_header(ramid, len); 1797 while (len) { 1798 uint64_t start_addr, block_length; 1799 start_addr = qemu_get_be64(mis->from_src_file); 1800 block_length = qemu_get_be64(mis->from_src_file); 1801 1802 len -= 16; 1803 int ret = ram_discard_range(ramid, start_addr, block_length); 1804 if (ret) { 1805 return ret; 1806 } 1807 } 1808 trace_loadvm_postcopy_ram_handle_discard_end(); 1809 1810 return 0; 1811 } 1812 1813 /* 1814 * Triggered by a postcopy_listen command; this thread takes over reading 1815 * the input stream, leaving the main thread free to carry on loading the rest 1816 * of the device state (from RAM). 1817 * (TODO:This could do with being in a postcopy file - but there again it's 1818 * just another input loop, not that postcopy specific) 1819 */ 1820 static void *postcopy_ram_listen_thread(void *opaque) 1821 { 1822 MigrationIncomingState *mis = migration_incoming_get_current(); 1823 QEMUFile *f = mis->from_src_file; 1824 int load_res; 1825 MigrationState *migr = migrate_get_current(); 1826 1827 object_ref(OBJECT(migr)); 1828 1829 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 1830 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1831 qemu_sem_post(&mis->thread_sync_sem); 1832 trace_postcopy_ram_listen_thread_start(); 1833 1834 rcu_register_thread(); 1835 /* 1836 * Because we're a thread and not a coroutine we can't yield 1837 * in qemu_file, and thus we must be blocking now. 1838 */ 1839 qemu_file_set_blocking(f, true); 1840 load_res = qemu_loadvm_state_main(f, mis); 1841 1842 /* 1843 * This is tricky, but, mis->from_src_file can change after it 1844 * returns, when postcopy recovery happened. In the future, we may 1845 * want a wrapper for the QEMUFile handle. 1846 */ 1847 f = mis->from_src_file; 1848 1849 /* And non-blocking again so we don't block in any cleanup */ 1850 qemu_file_set_blocking(f, false); 1851 1852 trace_postcopy_ram_listen_thread_exit(); 1853 if (load_res < 0) { 1854 qemu_file_set_error(f, load_res); 1855 dirty_bitmap_mig_cancel_incoming(); 1856 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING && 1857 !migrate_postcopy_ram() && migrate_dirty_bitmaps()) 1858 { 1859 error_report("%s: loadvm failed during postcopy: %d. All states " 1860 "are migrated except dirty bitmaps. Some dirty " 1861 "bitmaps may be lost, and present migrated dirty " 1862 "bitmaps are correctly migrated and valid.", 1863 __func__, load_res); 1864 load_res = 0; /* prevent further exit() */ 1865 } else { 1866 error_report("%s: loadvm failed: %d", __func__, load_res); 1867 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1868 MIGRATION_STATUS_FAILED); 1869 } 1870 } 1871 if (load_res >= 0) { 1872 /* 1873 * This looks good, but it's possible that the device loading in the 1874 * main thread hasn't finished yet, and so we might not be in 'RUN' 1875 * state yet; wait for the end of the main thread. 1876 */ 1877 qemu_event_wait(&mis->main_thread_load_event); 1878 } 1879 postcopy_ram_incoming_cleanup(mis); 1880 1881 if (load_res < 0) { 1882 /* 1883 * If something went wrong then we have a bad state so exit; 1884 * depending how far we got it might be possible at this point 1885 * to leave the guest running and fire MCEs for pages that never 1886 * arrived as a desperate recovery step. 1887 */ 1888 rcu_unregister_thread(); 1889 exit(EXIT_FAILURE); 1890 } 1891 1892 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1893 MIGRATION_STATUS_COMPLETED); 1894 /* 1895 * If everything has worked fine, then the main thread has waited 1896 * for us to start, and we're the last use of the mis. 1897 * (If something broke then qemu will have to exit anyway since it's 1898 * got a bad migration state). 1899 */ 1900 migration_incoming_state_destroy(); 1901 qemu_loadvm_state_cleanup(); 1902 1903 rcu_unregister_thread(); 1904 mis->have_listen_thread = false; 1905 postcopy_state_set(POSTCOPY_INCOMING_END); 1906 1907 object_unref(OBJECT(migr)); 1908 1909 return NULL; 1910 } 1911 1912 /* After this message we must be able to immediately receive postcopy data */ 1913 static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) 1914 { 1915 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING); 1916 Error *local_err = NULL; 1917 1918 trace_loadvm_postcopy_handle_listen("enter"); 1919 1920 if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) { 1921 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps); 1922 return -1; 1923 } 1924 if (ps == POSTCOPY_INCOMING_ADVISE) { 1925 /* 1926 * A rare case, we entered listen without having to do any discards, 1927 * so do the setup that's normally done at the time of the 1st discard. 1928 */ 1929 if (migrate_postcopy_ram()) { 1930 postcopy_ram_prepare_discard(mis); 1931 } 1932 } 1933 1934 trace_loadvm_postcopy_handle_listen("after discard"); 1935 1936 /* 1937 * Sensitise RAM - can now generate requests for blocks that don't exist 1938 * However, at this point the CPU shouldn't be running, and the IO 1939 * shouldn't be doing anything yet so don't actually expect requests 1940 */ 1941 if (migrate_postcopy_ram()) { 1942 if (postcopy_ram_incoming_setup(mis)) { 1943 postcopy_ram_incoming_cleanup(mis); 1944 return -1; 1945 } 1946 } 1947 1948 trace_loadvm_postcopy_handle_listen("after uffd"); 1949 1950 if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) { 1951 error_report_err(local_err); 1952 return -1; 1953 } 1954 1955 mis->have_listen_thread = true; 1956 postcopy_thread_create(mis, &mis->listen_thread, "postcopy/listen", 1957 postcopy_ram_listen_thread, QEMU_THREAD_DETACHED); 1958 trace_loadvm_postcopy_handle_listen("return"); 1959 1960 return 0; 1961 } 1962 1963 static void loadvm_postcopy_handle_run_bh(void *opaque) 1964 { 1965 Error *local_err = NULL; 1966 MigrationIncomingState *mis = opaque; 1967 1968 trace_loadvm_postcopy_handle_run_bh("enter"); 1969 1970 /* TODO we should move all of this lot into postcopy_ram.c or a shared code 1971 * in migration.c 1972 */ 1973 cpu_synchronize_all_post_init(); 1974 1975 trace_loadvm_postcopy_handle_run_bh("after cpu sync"); 1976 1977 qemu_announce_self(&mis->announce_timer, migrate_announce_params()); 1978 1979 trace_loadvm_postcopy_handle_run_bh("after announce"); 1980 1981 /* Make sure all file formats throw away their mutable metadata. 1982 * If we get an error here, just don't restart the VM yet. */ 1983 bdrv_activate_all(&local_err); 1984 if (local_err) { 1985 error_report_err(local_err); 1986 local_err = NULL; 1987 autostart = false; 1988 } 1989 1990 trace_loadvm_postcopy_handle_run_bh("after invalidate cache"); 1991 1992 dirty_bitmap_mig_before_vm_start(); 1993 1994 if (autostart) { 1995 /* Hold onto your hats, starting the CPU */ 1996 vm_start(); 1997 } else { 1998 /* leave it paused and let management decide when to start the CPU */ 1999 runstate_set(RUN_STATE_PAUSED); 2000 } 2001 2002 qemu_bh_delete(mis->bh); 2003 2004 trace_loadvm_postcopy_handle_run_bh("return"); 2005 } 2006 2007 /* After all discards we can start running and asking for pages */ 2008 static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) 2009 { 2010 PostcopyState ps = postcopy_state_get(); 2011 2012 trace_loadvm_postcopy_handle_run(); 2013 if (ps != POSTCOPY_INCOMING_LISTENING) { 2014 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps); 2015 return -1; 2016 } 2017 2018 postcopy_state_set(POSTCOPY_INCOMING_RUNNING); 2019 mis->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, mis); 2020 qemu_bh_schedule(mis->bh); 2021 2022 /* We need to finish reading the stream from the package 2023 * and also stop reading anything more from the stream that loaded the 2024 * package (since it's now being read by the listener thread). 2025 * LOADVM_QUIT will quit all the layers of nested loadvm loops. 2026 */ 2027 return LOADVM_QUIT; 2028 } 2029 2030 /* We must be with page_request_mutex held */ 2031 static gboolean postcopy_sync_page_req(gpointer key, gpointer value, 2032 gpointer data) 2033 { 2034 MigrationIncomingState *mis = data; 2035 void *host_addr = (void *) key; 2036 ram_addr_t rb_offset; 2037 RAMBlock *rb; 2038 int ret; 2039 2040 rb = qemu_ram_block_from_host(host_addr, true, &rb_offset); 2041 if (!rb) { 2042 /* 2043 * This should _never_ happen. However be nice for a migrating VM to 2044 * not crash/assert. Post an error (note: intended to not use *_once 2045 * because we do want to see all the illegal addresses; and this can 2046 * never be triggered by the guest so we're safe) and move on next. 2047 */ 2048 error_report("%s: illegal host addr %p", __func__, host_addr); 2049 /* Try the next entry */ 2050 return FALSE; 2051 } 2052 2053 ret = migrate_send_rp_message_req_pages(mis, rb, rb_offset); 2054 if (ret) { 2055 /* Please refer to above comment. */ 2056 error_report("%s: send rp message failed for addr %p", 2057 __func__, host_addr); 2058 return FALSE; 2059 } 2060 2061 trace_postcopy_page_req_sync(host_addr); 2062 2063 return FALSE; 2064 } 2065 2066 static void migrate_send_rp_req_pages_pending(MigrationIncomingState *mis) 2067 { 2068 WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) { 2069 g_tree_foreach(mis->page_requested, postcopy_sync_page_req, mis); 2070 } 2071 } 2072 2073 static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis) 2074 { 2075 if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) { 2076 error_report("%s: illegal resume received", __func__); 2077 /* Don't fail the load, only for this. */ 2078 return 0; 2079 } 2080 2081 /* 2082 * Reset the last_rb before we resend any page req to source again, since 2083 * the source should have it reset already. 2084 */ 2085 mis->last_rb = NULL; 2086 2087 /* 2088 * This means source VM is ready to resume the postcopy migration. 2089 */ 2090 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER, 2091 MIGRATION_STATUS_POSTCOPY_ACTIVE); 2092 2093 trace_loadvm_postcopy_handle_resume(); 2094 2095 /* Tell source that "we are ready" */ 2096 migrate_send_rp_resume_ack(mis, MIGRATION_RESUME_ACK_VALUE); 2097 2098 /* 2099 * After a postcopy recovery, the source should have lost the postcopy 2100 * queue, or potentially the requested pages could have been lost during 2101 * the network down phase. Let's re-sync with the source VM by re-sending 2102 * all the pending pages that we eagerly need, so these threads won't get 2103 * blocked too long due to the recovery. 2104 * 2105 * Without this procedure, the faulted destination VM threads (waiting for 2106 * page requests right before the postcopy is interrupted) can keep hanging 2107 * until the pages are sent by the source during the background copying of 2108 * pages, or another thread faulted on the same address accidentally. 2109 */ 2110 migrate_send_rp_req_pages_pending(mis); 2111 2112 /* 2113 * It's time to switch state and release the fault thread to continue 2114 * service page faults. Note that this should be explicitly after the 2115 * above call to migrate_send_rp_req_pages_pending(). In short: 2116 * migrate_send_rp_message_req_pages() is not thread safe, yet. 2117 */ 2118 qemu_sem_post(&mis->postcopy_pause_sem_fault); 2119 2120 if (migrate_postcopy_preempt()) { 2121 /* The channel should already be setup again; make sure of it */ 2122 assert(mis->postcopy_qemufile_dst); 2123 /* Kick the fast ram load thread too */ 2124 qemu_sem_post(&mis->postcopy_pause_sem_fast_load); 2125 } 2126 2127 return 0; 2128 } 2129 2130 /** 2131 * Immediately following this command is a blob of data containing an embedded 2132 * chunk of migration stream; read it and load it. 2133 * 2134 * @mis: Incoming state 2135 * @length: Length of packaged data to read 2136 * 2137 * Returns: Negative values on error 2138 * 2139 */ 2140 static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis) 2141 { 2142 int ret; 2143 size_t length; 2144 QIOChannelBuffer *bioc; 2145 2146 length = qemu_get_be32(mis->from_src_file); 2147 trace_loadvm_handle_cmd_packaged(length); 2148 2149 if (length > MAX_VM_CMD_PACKAGED_SIZE) { 2150 error_report("Unreasonably large packaged state: %zu", length); 2151 return -1; 2152 } 2153 2154 bioc = qio_channel_buffer_new(length); 2155 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-loadvm-buffer"); 2156 ret = qemu_get_buffer(mis->from_src_file, 2157 bioc->data, 2158 length); 2159 if (ret != length) { 2160 object_unref(OBJECT(bioc)); 2161 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu", 2162 ret, length); 2163 return (ret < 0) ? ret : -EAGAIN; 2164 } 2165 bioc->usage += length; 2166 trace_loadvm_handle_cmd_packaged_received(ret); 2167 2168 QEMUFile *packf = qemu_file_new_input(QIO_CHANNEL(bioc)); 2169 2170 ret = qemu_loadvm_state_main(packf, mis); 2171 trace_loadvm_handle_cmd_packaged_main(ret); 2172 qemu_fclose(packf); 2173 object_unref(OBJECT(bioc)); 2174 2175 return ret; 2176 } 2177 2178 /* 2179 * Handle request that source requests for recved_bitmap on 2180 * destination. Payload format: 2181 * 2182 * len (1 byte) + ramblock_name (<255 bytes) 2183 */ 2184 static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis, 2185 uint16_t len) 2186 { 2187 QEMUFile *file = mis->from_src_file; 2188 RAMBlock *rb; 2189 char block_name[256]; 2190 size_t cnt; 2191 2192 cnt = qemu_get_counted_string(file, block_name); 2193 if (!cnt) { 2194 error_report("%s: failed to read block name", __func__); 2195 return -EINVAL; 2196 } 2197 2198 /* Validate before using the data */ 2199 if (qemu_file_get_error(file)) { 2200 return qemu_file_get_error(file); 2201 } 2202 2203 if (len != cnt + 1) { 2204 error_report("%s: invalid payload length (%d)", __func__, len); 2205 return -EINVAL; 2206 } 2207 2208 rb = qemu_ram_block_by_name(block_name); 2209 if (!rb) { 2210 error_report("%s: block '%s' not found", __func__, block_name); 2211 return -EINVAL; 2212 } 2213 2214 migrate_send_rp_recv_bitmap(mis, block_name); 2215 2216 trace_loadvm_handle_recv_bitmap(block_name); 2217 2218 return 0; 2219 } 2220 2221 static int loadvm_process_enable_colo(MigrationIncomingState *mis) 2222 { 2223 int ret = migration_incoming_enable_colo(); 2224 2225 if (!ret) { 2226 ret = colo_init_ram_cache(); 2227 if (ret) { 2228 migration_incoming_disable_colo(); 2229 } 2230 } 2231 return ret; 2232 } 2233 2234 /* 2235 * Process an incoming 'QEMU_VM_COMMAND' 2236 * 0 just a normal return 2237 * LOADVM_QUIT All good, but exit the loop 2238 * <0 Error 2239 */ 2240 static int loadvm_process_command(QEMUFile *f) 2241 { 2242 MigrationIncomingState *mis = migration_incoming_get_current(); 2243 uint16_t cmd; 2244 uint16_t len; 2245 uint32_t tmp32; 2246 2247 cmd = qemu_get_be16(f); 2248 len = qemu_get_be16(f); 2249 2250 /* Check validity before continue processing of cmds */ 2251 if (qemu_file_get_error(f)) { 2252 return qemu_file_get_error(f); 2253 } 2254 2255 if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) { 2256 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len); 2257 return -EINVAL; 2258 } 2259 2260 trace_loadvm_process_command(mig_cmd_args[cmd].name, len); 2261 2262 if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) { 2263 error_report("%s received with bad length - expecting %zu, got %d", 2264 mig_cmd_args[cmd].name, 2265 (size_t)mig_cmd_args[cmd].len, len); 2266 return -ERANGE; 2267 } 2268 2269 switch (cmd) { 2270 case MIG_CMD_OPEN_RETURN_PATH: 2271 if (mis->to_src_file) { 2272 error_report("CMD_OPEN_RETURN_PATH called when RP already open"); 2273 /* Not really a problem, so don't give up */ 2274 return 0; 2275 } 2276 mis->to_src_file = qemu_file_get_return_path(f); 2277 if (!mis->to_src_file) { 2278 error_report("CMD_OPEN_RETURN_PATH failed"); 2279 return -1; 2280 } 2281 break; 2282 2283 case MIG_CMD_PING: 2284 tmp32 = qemu_get_be32(f); 2285 trace_loadvm_process_command_ping(tmp32); 2286 if (!mis->to_src_file) { 2287 error_report("CMD_PING (0x%x) received with no return path", 2288 tmp32); 2289 return -1; 2290 } 2291 migrate_send_rp_pong(mis, tmp32); 2292 break; 2293 2294 case MIG_CMD_PACKAGED: 2295 return loadvm_handle_cmd_packaged(mis); 2296 2297 case MIG_CMD_POSTCOPY_ADVISE: 2298 return loadvm_postcopy_handle_advise(mis, len); 2299 2300 case MIG_CMD_POSTCOPY_LISTEN: 2301 return loadvm_postcopy_handle_listen(mis); 2302 2303 case MIG_CMD_POSTCOPY_RUN: 2304 return loadvm_postcopy_handle_run(mis); 2305 2306 case MIG_CMD_POSTCOPY_RAM_DISCARD: 2307 return loadvm_postcopy_ram_handle_discard(mis, len); 2308 2309 case MIG_CMD_POSTCOPY_RESUME: 2310 return loadvm_postcopy_handle_resume(mis); 2311 2312 case MIG_CMD_RECV_BITMAP: 2313 return loadvm_handle_recv_bitmap(mis, len); 2314 2315 case MIG_CMD_ENABLE_COLO: 2316 return loadvm_process_enable_colo(mis); 2317 } 2318 2319 return 0; 2320 } 2321 2322 /* 2323 * Read a footer off the wire and check that it matches the expected section 2324 * 2325 * Returns: true if the footer was good 2326 * false if there is a problem (and calls error_report to say why) 2327 */ 2328 static bool check_section_footer(QEMUFile *f, SaveStateEntry *se) 2329 { 2330 int ret; 2331 uint8_t read_mark; 2332 uint32_t read_section_id; 2333 2334 if (!migrate_get_current()->send_section_footer) { 2335 /* No footer to check */ 2336 return true; 2337 } 2338 2339 read_mark = qemu_get_byte(f); 2340 2341 ret = qemu_file_get_error(f); 2342 if (ret) { 2343 error_report("%s: Read section footer failed: %d", 2344 __func__, ret); 2345 return false; 2346 } 2347 2348 if (read_mark != QEMU_VM_SECTION_FOOTER) { 2349 error_report("Missing section footer for %s", se->idstr); 2350 return false; 2351 } 2352 2353 read_section_id = qemu_get_be32(f); 2354 if (read_section_id != se->load_section_id) { 2355 error_report("Mismatched section id in footer for %s -" 2356 " read 0x%x expected 0x%x", 2357 se->idstr, read_section_id, se->load_section_id); 2358 return false; 2359 } 2360 2361 /* All good */ 2362 return true; 2363 } 2364 2365 static int 2366 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis) 2367 { 2368 uint32_t instance_id, version_id, section_id; 2369 SaveStateEntry *se; 2370 char idstr[256]; 2371 int ret; 2372 2373 /* Read section start */ 2374 section_id = qemu_get_be32(f); 2375 if (!qemu_get_counted_string(f, idstr)) { 2376 error_report("Unable to read ID string for section %u", 2377 section_id); 2378 return -EINVAL; 2379 } 2380 instance_id = qemu_get_be32(f); 2381 version_id = qemu_get_be32(f); 2382 2383 ret = qemu_file_get_error(f); 2384 if (ret) { 2385 error_report("%s: Failed to read instance/version ID: %d", 2386 __func__, ret); 2387 return ret; 2388 } 2389 2390 trace_qemu_loadvm_state_section_startfull(section_id, idstr, 2391 instance_id, version_id); 2392 /* Find savevm section */ 2393 se = find_se(idstr, instance_id); 2394 if (se == NULL) { 2395 error_report("Unknown savevm section or instance '%s' %"PRIu32". " 2396 "Make sure that your current VM setup matches your " 2397 "saved VM setup, including any hotplugged devices", 2398 idstr, instance_id); 2399 return -EINVAL; 2400 } 2401 2402 /* Validate version */ 2403 if (version_id > se->version_id) { 2404 error_report("savevm: unsupported version %d for '%s' v%d", 2405 version_id, idstr, se->version_id); 2406 return -EINVAL; 2407 } 2408 se->load_version_id = version_id; 2409 se->load_section_id = section_id; 2410 2411 /* Validate if it is a device's state */ 2412 if (xen_enabled() && se->is_ram) { 2413 error_report("loadvm: %s RAM loading not allowed on Xen", idstr); 2414 return -EINVAL; 2415 } 2416 2417 ret = vmstate_load(f, se); 2418 if (ret < 0) { 2419 error_report("error while loading state for instance 0x%"PRIx32" of" 2420 " device '%s'", instance_id, idstr); 2421 return ret; 2422 } 2423 if (!check_section_footer(f, se)) { 2424 return -EINVAL; 2425 } 2426 2427 return 0; 2428 } 2429 2430 static int 2431 qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis) 2432 { 2433 uint32_t section_id; 2434 SaveStateEntry *se; 2435 int ret; 2436 2437 section_id = qemu_get_be32(f); 2438 2439 ret = qemu_file_get_error(f); 2440 if (ret) { 2441 error_report("%s: Failed to read section ID: %d", 2442 __func__, ret); 2443 return ret; 2444 } 2445 2446 trace_qemu_loadvm_state_section_partend(section_id); 2447 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2448 if (se->load_section_id == section_id) { 2449 break; 2450 } 2451 } 2452 if (se == NULL) { 2453 error_report("Unknown savevm section %d", section_id); 2454 return -EINVAL; 2455 } 2456 2457 ret = vmstate_load(f, se); 2458 if (ret < 0) { 2459 error_report("error while loading state section id %d(%s)", 2460 section_id, se->idstr); 2461 return ret; 2462 } 2463 if (!check_section_footer(f, se)) { 2464 return -EINVAL; 2465 } 2466 2467 return 0; 2468 } 2469 2470 static int qemu_loadvm_state_header(QEMUFile *f) 2471 { 2472 unsigned int v; 2473 int ret; 2474 2475 v = qemu_get_be32(f); 2476 if (v != QEMU_VM_FILE_MAGIC) { 2477 error_report("Not a migration stream"); 2478 return -EINVAL; 2479 } 2480 2481 v = qemu_get_be32(f); 2482 if (v == QEMU_VM_FILE_VERSION_COMPAT) { 2483 error_report("SaveVM v2 format is obsolete and don't work anymore"); 2484 return -ENOTSUP; 2485 } 2486 if (v != QEMU_VM_FILE_VERSION) { 2487 error_report("Unsupported migration stream version"); 2488 return -ENOTSUP; 2489 } 2490 2491 if (migrate_get_current()->send_configuration) { 2492 if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) { 2493 error_report("Configuration section missing"); 2494 qemu_loadvm_state_cleanup(); 2495 return -EINVAL; 2496 } 2497 ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0); 2498 2499 if (ret) { 2500 qemu_loadvm_state_cleanup(); 2501 return ret; 2502 } 2503 } 2504 return 0; 2505 } 2506 2507 static int qemu_loadvm_state_setup(QEMUFile *f) 2508 { 2509 SaveStateEntry *se; 2510 int ret; 2511 2512 trace_loadvm_state_setup(); 2513 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2514 if (!se->ops || !se->ops->load_setup) { 2515 continue; 2516 } 2517 if (se->ops->is_active) { 2518 if (!se->ops->is_active(se->opaque)) { 2519 continue; 2520 } 2521 } 2522 2523 ret = se->ops->load_setup(f, se->opaque); 2524 if (ret < 0) { 2525 qemu_file_set_error(f, ret); 2526 error_report("Load state of device %s failed", se->idstr); 2527 return ret; 2528 } 2529 } 2530 return 0; 2531 } 2532 2533 void qemu_loadvm_state_cleanup(void) 2534 { 2535 SaveStateEntry *se; 2536 2537 trace_loadvm_state_cleanup(); 2538 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 2539 if (se->ops && se->ops->load_cleanup) { 2540 se->ops->load_cleanup(se->opaque); 2541 } 2542 } 2543 } 2544 2545 /* Return true if we should continue the migration, or false. */ 2546 static bool postcopy_pause_incoming(MigrationIncomingState *mis) 2547 { 2548 int i; 2549 2550 trace_postcopy_pause_incoming(); 2551 2552 assert(migrate_postcopy_ram()); 2553 2554 /* 2555 * Unregister yank with either from/to src would work, since ioc behind it 2556 * is the same 2557 */ 2558 migration_ioc_unregister_yank_from_file(mis->from_src_file); 2559 2560 assert(mis->from_src_file); 2561 qemu_file_shutdown(mis->from_src_file); 2562 qemu_fclose(mis->from_src_file); 2563 mis->from_src_file = NULL; 2564 2565 assert(mis->to_src_file); 2566 qemu_file_shutdown(mis->to_src_file); 2567 qemu_mutex_lock(&mis->rp_mutex); 2568 qemu_fclose(mis->to_src_file); 2569 mis->to_src_file = NULL; 2570 qemu_mutex_unlock(&mis->rp_mutex); 2571 2572 /* 2573 * NOTE: this must happen before reset the PostcopyTmpPages below, 2574 * otherwise it's racy to reset those fields when the fast load thread 2575 * can be accessing it in parallel. 2576 */ 2577 if (mis->postcopy_qemufile_dst) { 2578 qemu_file_shutdown(mis->postcopy_qemufile_dst); 2579 /* Take the mutex to make sure the fast ram load thread halted */ 2580 qemu_mutex_lock(&mis->postcopy_prio_thread_mutex); 2581 migration_ioc_unregister_yank_from_file(mis->postcopy_qemufile_dst); 2582 qemu_fclose(mis->postcopy_qemufile_dst); 2583 mis->postcopy_qemufile_dst = NULL; 2584 qemu_mutex_unlock(&mis->postcopy_prio_thread_mutex); 2585 } 2586 2587 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 2588 MIGRATION_STATUS_POSTCOPY_PAUSED); 2589 2590 /* Notify the fault thread for the invalidated file handle */ 2591 postcopy_fault_thread_notify(mis); 2592 2593 /* 2594 * If network is interrupted, any temp page we received will be useless 2595 * because we didn't mark them as "received" in receivedmap. After a 2596 * proper recovery later (which will sync src dirty bitmap with receivedmap 2597 * on dest) these cached small pages will be resent again. 2598 */ 2599 for (i = 0; i < mis->postcopy_channels; i++) { 2600 postcopy_temp_page_reset(&mis->postcopy_tmp_pages[i]); 2601 } 2602 2603 error_report("Detected IO failure for postcopy. " 2604 "Migration paused."); 2605 2606 while (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) { 2607 qemu_sem_wait(&mis->postcopy_pause_sem_dst); 2608 } 2609 2610 trace_postcopy_pause_incoming_continued(); 2611 2612 return true; 2613 } 2614 2615 int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis) 2616 { 2617 uint8_t section_type; 2618 int ret = 0; 2619 2620 retry: 2621 while (true) { 2622 section_type = qemu_get_byte(f); 2623 2624 ret = qemu_file_get_error_obj_any(f, mis->postcopy_qemufile_dst, NULL); 2625 if (ret) { 2626 break; 2627 } 2628 2629 trace_qemu_loadvm_state_section(section_type); 2630 switch (section_type) { 2631 case QEMU_VM_SECTION_START: 2632 case QEMU_VM_SECTION_FULL: 2633 ret = qemu_loadvm_section_start_full(f, mis); 2634 if (ret < 0) { 2635 goto out; 2636 } 2637 break; 2638 case QEMU_VM_SECTION_PART: 2639 case QEMU_VM_SECTION_END: 2640 ret = qemu_loadvm_section_part_end(f, mis); 2641 if (ret < 0) { 2642 goto out; 2643 } 2644 break; 2645 case QEMU_VM_COMMAND: 2646 ret = loadvm_process_command(f); 2647 trace_qemu_loadvm_state_section_command(ret); 2648 if ((ret < 0) || (ret == LOADVM_QUIT)) { 2649 goto out; 2650 } 2651 break; 2652 case QEMU_VM_EOF: 2653 /* This is the end of migration */ 2654 goto out; 2655 default: 2656 error_report("Unknown savevm section type %d", section_type); 2657 ret = -EINVAL; 2658 goto out; 2659 } 2660 } 2661 2662 out: 2663 if (ret < 0) { 2664 qemu_file_set_error(f, ret); 2665 2666 /* Cancel bitmaps incoming regardless of recovery */ 2667 dirty_bitmap_mig_cancel_incoming(); 2668 2669 /* 2670 * If we are during an active postcopy, then we pause instead 2671 * of bail out to at least keep the VM's dirty data. Note 2672 * that POSTCOPY_INCOMING_LISTENING stage is still not enough, 2673 * during which we're still receiving device states and we 2674 * still haven't yet started the VM on destination. 2675 * 2676 * Only RAM postcopy supports recovery. Still, if RAM postcopy is 2677 * enabled, canceled bitmaps postcopy will not affect RAM postcopy 2678 * recovering. 2679 */ 2680 if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING && 2681 migrate_postcopy_ram() && postcopy_pause_incoming(mis)) { 2682 /* Reset f to point to the newly created channel */ 2683 f = mis->from_src_file; 2684 goto retry; 2685 } 2686 } 2687 return ret; 2688 } 2689 2690 int qemu_loadvm_state(QEMUFile *f) 2691 { 2692 MigrationIncomingState *mis = migration_incoming_get_current(); 2693 Error *local_err = NULL; 2694 int ret; 2695 2696 if (qemu_savevm_state_blocked(&local_err)) { 2697 error_report_err(local_err); 2698 return -EINVAL; 2699 } 2700 2701 ret = qemu_loadvm_state_header(f); 2702 if (ret) { 2703 return ret; 2704 } 2705 2706 if (qemu_loadvm_state_setup(f) != 0) { 2707 return -EINVAL; 2708 } 2709 2710 cpu_synchronize_all_pre_loadvm(); 2711 2712 ret = qemu_loadvm_state_main(f, mis); 2713 qemu_event_set(&mis->main_thread_load_event); 2714 2715 trace_qemu_loadvm_state_post_main(ret); 2716 2717 if (mis->have_listen_thread) { 2718 /* Listen thread still going, can't clean up yet */ 2719 return ret; 2720 } 2721 2722 if (ret == 0) { 2723 ret = qemu_file_get_error(f); 2724 } 2725 2726 /* 2727 * Try to read in the VMDESC section as well, so that dumping tools that 2728 * intercept our migration stream have the chance to see it. 2729 */ 2730 2731 /* We've got to be careful; if we don't read the data and just shut the fd 2732 * then the sender can error if we close while it's still sending. 2733 * We also mustn't read data that isn't there; some transports (RDMA) 2734 * will stall waiting for that data when the source has already closed. 2735 */ 2736 if (ret == 0 && should_send_vmdesc()) { 2737 uint8_t *buf; 2738 uint32_t size; 2739 uint8_t section_type = qemu_get_byte(f); 2740 2741 if (section_type != QEMU_VM_VMDESCRIPTION) { 2742 error_report("Expected vmdescription section, but got %d", 2743 section_type); 2744 /* 2745 * It doesn't seem worth failing at this point since 2746 * we apparently have an otherwise valid VM state 2747 */ 2748 } else { 2749 buf = g_malloc(0x1000); 2750 size = qemu_get_be32(f); 2751 2752 while (size > 0) { 2753 uint32_t read_chunk = MIN(size, 0x1000); 2754 qemu_get_buffer(f, buf, read_chunk); 2755 size -= read_chunk; 2756 } 2757 g_free(buf); 2758 } 2759 } 2760 2761 qemu_loadvm_state_cleanup(); 2762 cpu_synchronize_all_post_init(); 2763 2764 return ret; 2765 } 2766 2767 int qemu_load_device_state(QEMUFile *f) 2768 { 2769 MigrationIncomingState *mis = migration_incoming_get_current(); 2770 int ret; 2771 2772 /* Load QEMU_VM_SECTION_FULL section */ 2773 ret = qemu_loadvm_state_main(f, mis); 2774 if (ret < 0) { 2775 error_report("Failed to load device state: %d", ret); 2776 return ret; 2777 } 2778 2779 cpu_synchronize_all_post_init(); 2780 return 0; 2781 } 2782 2783 bool save_snapshot(const char *name, bool overwrite, const char *vmstate, 2784 bool has_devices, strList *devices, Error **errp) 2785 { 2786 BlockDriverState *bs; 2787 QEMUSnapshotInfo sn1, *sn = &sn1; 2788 int ret = -1, ret2; 2789 QEMUFile *f; 2790 int saved_vm_running; 2791 uint64_t vm_state_size; 2792 g_autoptr(GDateTime) now = g_date_time_new_now_local(); 2793 AioContext *aio_context; 2794 2795 GLOBAL_STATE_CODE(); 2796 2797 if (migration_is_blocked(errp)) { 2798 return false; 2799 } 2800 2801 if (!replay_can_snapshot()) { 2802 error_setg(errp, "Record/replay does not allow making snapshot " 2803 "right now. Try once more later."); 2804 return false; 2805 } 2806 2807 if (!bdrv_all_can_snapshot(has_devices, devices, errp)) { 2808 return false; 2809 } 2810 2811 /* Delete old snapshots of the same name */ 2812 if (name) { 2813 if (overwrite) { 2814 if (bdrv_all_delete_snapshot(name, has_devices, 2815 devices, errp) < 0) { 2816 return false; 2817 } 2818 } else { 2819 ret2 = bdrv_all_has_snapshot(name, has_devices, devices, errp); 2820 if (ret2 < 0) { 2821 return false; 2822 } 2823 if (ret2 == 1) { 2824 error_setg(errp, 2825 "Snapshot '%s' already exists in one or more devices", 2826 name); 2827 return false; 2828 } 2829 } 2830 } 2831 2832 bs = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp); 2833 if (bs == NULL) { 2834 return false; 2835 } 2836 aio_context = bdrv_get_aio_context(bs); 2837 2838 saved_vm_running = runstate_is_running(); 2839 2840 ret = global_state_store(); 2841 if (ret) { 2842 error_setg(errp, "Error saving global state"); 2843 return false; 2844 } 2845 vm_stop(RUN_STATE_SAVE_VM); 2846 2847 bdrv_drain_all_begin(); 2848 2849 aio_context_acquire(aio_context); 2850 2851 memset(sn, 0, sizeof(*sn)); 2852 2853 /* fill auxiliary fields */ 2854 sn->date_sec = g_date_time_to_unix(now); 2855 sn->date_nsec = g_date_time_get_microsecond(now) * 1000; 2856 sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 2857 if (replay_mode != REPLAY_MODE_NONE) { 2858 sn->icount = replay_get_current_icount(); 2859 } else { 2860 sn->icount = -1ULL; 2861 } 2862 2863 if (name) { 2864 pstrcpy(sn->name, sizeof(sn->name), name); 2865 } else { 2866 g_autofree char *autoname = g_date_time_format(now, "vm-%Y%m%d%H%M%S"); 2867 pstrcpy(sn->name, sizeof(sn->name), autoname); 2868 } 2869 2870 /* save the VM state */ 2871 f = qemu_fopen_bdrv(bs, 1); 2872 if (!f) { 2873 error_setg(errp, "Could not open VM state file"); 2874 goto the_end; 2875 } 2876 ret = qemu_savevm_state(f, errp); 2877 vm_state_size = qemu_file_total_transferred(f); 2878 ret2 = qemu_fclose(f); 2879 if (ret < 0) { 2880 goto the_end; 2881 } 2882 if (ret2 < 0) { 2883 ret = ret2; 2884 goto the_end; 2885 } 2886 2887 /* The bdrv_all_create_snapshot() call that follows acquires the AioContext 2888 * for itself. BDRV_POLL_WHILE() does not support nested locking because 2889 * it only releases the lock once. Therefore synchronous I/O will deadlock 2890 * unless we release the AioContext before bdrv_all_create_snapshot(). 2891 */ 2892 aio_context_release(aio_context); 2893 aio_context = NULL; 2894 2895 ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, 2896 has_devices, devices, errp); 2897 if (ret < 0) { 2898 bdrv_all_delete_snapshot(sn->name, has_devices, devices, NULL); 2899 goto the_end; 2900 } 2901 2902 ret = 0; 2903 2904 the_end: 2905 if (aio_context) { 2906 aio_context_release(aio_context); 2907 } 2908 2909 bdrv_drain_all_end(); 2910 2911 if (saved_vm_running) { 2912 vm_start(); 2913 } 2914 return ret == 0; 2915 } 2916 2917 void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live, 2918 Error **errp) 2919 { 2920 QEMUFile *f; 2921 QIOChannelFile *ioc; 2922 int saved_vm_running; 2923 int ret; 2924 2925 if (!has_live) { 2926 /* live default to true so old version of Xen tool stack can have a 2927 * successful live migration */ 2928 live = true; 2929 } 2930 2931 saved_vm_running = runstate_is_running(); 2932 vm_stop(RUN_STATE_SAVE_VM); 2933 global_state_store_running(); 2934 2935 ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT | O_TRUNC, 2936 0660, errp); 2937 if (!ioc) { 2938 goto the_end; 2939 } 2940 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-save-state"); 2941 f = qemu_file_new_output(QIO_CHANNEL(ioc)); 2942 object_unref(OBJECT(ioc)); 2943 ret = qemu_save_device_state(f); 2944 if (ret < 0 || qemu_fclose(f) < 0) { 2945 error_setg(errp, QERR_IO_ERROR); 2946 } else { 2947 /* libxl calls the QMP command "stop" before calling 2948 * "xen-save-devices-state" and in case of migration failure, libxl 2949 * would call "cont". 2950 * So call bdrv_inactivate_all (release locks) here to let the other 2951 * side of the migration take control of the images. 2952 */ 2953 if (live && !saved_vm_running) { 2954 ret = bdrv_inactivate_all(); 2955 if (ret) { 2956 error_setg(errp, "%s: bdrv_inactivate_all() failed (%d)", 2957 __func__, ret); 2958 } 2959 } 2960 } 2961 2962 the_end: 2963 if (saved_vm_running) { 2964 vm_start(); 2965 } 2966 } 2967 2968 void qmp_xen_load_devices_state(const char *filename, Error **errp) 2969 { 2970 QEMUFile *f; 2971 QIOChannelFile *ioc; 2972 int ret; 2973 2974 /* Guest must be paused before loading the device state; the RAM state 2975 * will already have been loaded by xc 2976 */ 2977 if (runstate_is_running()) { 2978 error_setg(errp, "Cannot update device state while vm is running"); 2979 return; 2980 } 2981 vm_stop(RUN_STATE_RESTORE_VM); 2982 2983 ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0, errp); 2984 if (!ioc) { 2985 return; 2986 } 2987 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-load-state"); 2988 f = qemu_file_new_input(QIO_CHANNEL(ioc)); 2989 object_unref(OBJECT(ioc)); 2990 2991 ret = qemu_loadvm_state(f); 2992 qemu_fclose(f); 2993 if (ret < 0) { 2994 error_setg(errp, QERR_IO_ERROR); 2995 } 2996 migration_incoming_state_destroy(); 2997 } 2998 2999 bool load_snapshot(const char *name, const char *vmstate, 3000 bool has_devices, strList *devices, Error **errp) 3001 { 3002 BlockDriverState *bs_vm_state; 3003 QEMUSnapshotInfo sn; 3004 QEMUFile *f; 3005 int ret; 3006 AioContext *aio_context; 3007 MigrationIncomingState *mis = migration_incoming_get_current(); 3008 3009 if (!bdrv_all_can_snapshot(has_devices, devices, errp)) { 3010 return false; 3011 } 3012 ret = bdrv_all_has_snapshot(name, has_devices, devices, errp); 3013 if (ret < 0) { 3014 return false; 3015 } 3016 if (ret == 0) { 3017 error_setg(errp, "Snapshot '%s' does not exist in one or more devices", 3018 name); 3019 return false; 3020 } 3021 3022 bs_vm_state = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp); 3023 if (!bs_vm_state) { 3024 return false; 3025 } 3026 aio_context = bdrv_get_aio_context(bs_vm_state); 3027 3028 /* Don't even try to load empty VM states */ 3029 aio_context_acquire(aio_context); 3030 ret = bdrv_snapshot_find(bs_vm_state, &sn, name); 3031 aio_context_release(aio_context); 3032 if (ret < 0) { 3033 return false; 3034 } else if (sn.vm_state_size == 0) { 3035 error_setg(errp, "This is a disk-only snapshot. Revert to it " 3036 " offline using qemu-img"); 3037 return false; 3038 } 3039 3040 /* 3041 * Flush the record/replay queue. Now the VM state is going 3042 * to change. Therefore we don't need to preserve its consistency 3043 */ 3044 replay_flush_events(); 3045 3046 /* Flush all IO requests so they don't interfere with the new state. */ 3047 bdrv_drain_all_begin(); 3048 3049 ret = bdrv_all_goto_snapshot(name, has_devices, devices, errp); 3050 if (ret < 0) { 3051 goto err_drain; 3052 } 3053 3054 /* restore the VM state */ 3055 f = qemu_fopen_bdrv(bs_vm_state, 0); 3056 if (!f) { 3057 error_setg(errp, "Could not open VM state file"); 3058 goto err_drain; 3059 } 3060 3061 qemu_system_reset(SHUTDOWN_CAUSE_NONE); 3062 mis->from_src_file = f; 3063 3064 if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) { 3065 ret = -EINVAL; 3066 goto err_drain; 3067 } 3068 aio_context_acquire(aio_context); 3069 ret = qemu_loadvm_state(f); 3070 migration_incoming_state_destroy(); 3071 aio_context_release(aio_context); 3072 3073 bdrv_drain_all_end(); 3074 3075 if (ret < 0) { 3076 error_setg(errp, "Error %d while loading VM state", ret); 3077 return false; 3078 } 3079 3080 return true; 3081 3082 err_drain: 3083 bdrv_drain_all_end(); 3084 return false; 3085 } 3086 3087 bool delete_snapshot(const char *name, bool has_devices, 3088 strList *devices, Error **errp) 3089 { 3090 if (!bdrv_all_can_snapshot(has_devices, devices, errp)) { 3091 return false; 3092 } 3093 3094 if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) { 3095 return false; 3096 } 3097 3098 return true; 3099 } 3100 3101 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev) 3102 { 3103 qemu_ram_set_idstr(mr->ram_block, 3104 memory_region_name(mr), dev); 3105 qemu_ram_set_migratable(mr->ram_block); 3106 } 3107 3108 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev) 3109 { 3110 qemu_ram_unset_idstr(mr->ram_block); 3111 qemu_ram_unset_migratable(mr->ram_block); 3112 } 3113 3114 void vmstate_register_ram_global(MemoryRegion *mr) 3115 { 3116 vmstate_register_ram(mr, NULL); 3117 } 3118 3119 bool vmstate_check_only_migratable(const VMStateDescription *vmsd) 3120 { 3121 /* check needed if --only-migratable is specified */ 3122 if (!only_migratable) { 3123 return true; 3124 } 3125 3126 return !(vmsd && vmsd->unmigratable); 3127 } 3128 3129 typedef struct SnapshotJob { 3130 Job common; 3131 char *tag; 3132 char *vmstate; 3133 strList *devices; 3134 Coroutine *co; 3135 Error **errp; 3136 bool ret; 3137 } SnapshotJob; 3138 3139 static void qmp_snapshot_job_free(SnapshotJob *s) 3140 { 3141 g_free(s->tag); 3142 g_free(s->vmstate); 3143 qapi_free_strList(s->devices); 3144 } 3145 3146 3147 static void snapshot_load_job_bh(void *opaque) 3148 { 3149 Job *job = opaque; 3150 SnapshotJob *s = container_of(job, SnapshotJob, common); 3151 int orig_vm_running; 3152 3153 job_progress_set_remaining(&s->common, 1); 3154 3155 orig_vm_running = runstate_is_running(); 3156 vm_stop(RUN_STATE_RESTORE_VM); 3157 3158 s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp); 3159 if (s->ret && orig_vm_running) { 3160 vm_start(); 3161 } 3162 3163 job_progress_update(&s->common, 1); 3164 3165 qmp_snapshot_job_free(s); 3166 aio_co_wake(s->co); 3167 } 3168 3169 static void snapshot_save_job_bh(void *opaque) 3170 { 3171 Job *job = opaque; 3172 SnapshotJob *s = container_of(job, SnapshotJob, common); 3173 3174 job_progress_set_remaining(&s->common, 1); 3175 s->ret = save_snapshot(s->tag, false, s->vmstate, 3176 true, s->devices, s->errp); 3177 job_progress_update(&s->common, 1); 3178 3179 qmp_snapshot_job_free(s); 3180 aio_co_wake(s->co); 3181 } 3182 3183 static void snapshot_delete_job_bh(void *opaque) 3184 { 3185 Job *job = opaque; 3186 SnapshotJob *s = container_of(job, SnapshotJob, common); 3187 3188 job_progress_set_remaining(&s->common, 1); 3189 s->ret = delete_snapshot(s->tag, true, s->devices, s->errp); 3190 job_progress_update(&s->common, 1); 3191 3192 qmp_snapshot_job_free(s); 3193 aio_co_wake(s->co); 3194 } 3195 3196 static int coroutine_fn snapshot_save_job_run(Job *job, Error **errp) 3197 { 3198 SnapshotJob *s = container_of(job, SnapshotJob, common); 3199 s->errp = errp; 3200 s->co = qemu_coroutine_self(); 3201 aio_bh_schedule_oneshot(qemu_get_aio_context(), 3202 snapshot_save_job_bh, job); 3203 qemu_coroutine_yield(); 3204 return s->ret ? 0 : -1; 3205 } 3206 3207 static int coroutine_fn snapshot_load_job_run(Job *job, Error **errp) 3208 { 3209 SnapshotJob *s = container_of(job, SnapshotJob, common); 3210 s->errp = errp; 3211 s->co = qemu_coroutine_self(); 3212 aio_bh_schedule_oneshot(qemu_get_aio_context(), 3213 snapshot_load_job_bh, job); 3214 qemu_coroutine_yield(); 3215 return s->ret ? 0 : -1; 3216 } 3217 3218 static int coroutine_fn snapshot_delete_job_run(Job *job, Error **errp) 3219 { 3220 SnapshotJob *s = container_of(job, SnapshotJob, common); 3221 s->errp = errp; 3222 s->co = qemu_coroutine_self(); 3223 aio_bh_schedule_oneshot(qemu_get_aio_context(), 3224 snapshot_delete_job_bh, job); 3225 qemu_coroutine_yield(); 3226 return s->ret ? 0 : -1; 3227 } 3228 3229 3230 static const JobDriver snapshot_load_job_driver = { 3231 .instance_size = sizeof(SnapshotJob), 3232 .job_type = JOB_TYPE_SNAPSHOT_LOAD, 3233 .run = snapshot_load_job_run, 3234 }; 3235 3236 static const JobDriver snapshot_save_job_driver = { 3237 .instance_size = sizeof(SnapshotJob), 3238 .job_type = JOB_TYPE_SNAPSHOT_SAVE, 3239 .run = snapshot_save_job_run, 3240 }; 3241 3242 static const JobDriver snapshot_delete_job_driver = { 3243 .instance_size = sizeof(SnapshotJob), 3244 .job_type = JOB_TYPE_SNAPSHOT_DELETE, 3245 .run = snapshot_delete_job_run, 3246 }; 3247 3248 3249 void qmp_snapshot_save(const char *job_id, 3250 const char *tag, 3251 const char *vmstate, 3252 strList *devices, 3253 Error **errp) 3254 { 3255 SnapshotJob *s; 3256 3257 s = job_create(job_id, &snapshot_save_job_driver, NULL, 3258 qemu_get_aio_context(), JOB_MANUAL_DISMISS, 3259 NULL, NULL, errp); 3260 if (!s) { 3261 return; 3262 } 3263 3264 s->tag = g_strdup(tag); 3265 s->vmstate = g_strdup(vmstate); 3266 s->devices = QAPI_CLONE(strList, devices); 3267 3268 job_start(&s->common); 3269 } 3270 3271 void qmp_snapshot_load(const char *job_id, 3272 const char *tag, 3273 const char *vmstate, 3274 strList *devices, 3275 Error **errp) 3276 { 3277 SnapshotJob *s; 3278 3279 s = job_create(job_id, &snapshot_load_job_driver, NULL, 3280 qemu_get_aio_context(), JOB_MANUAL_DISMISS, 3281 NULL, NULL, errp); 3282 if (!s) { 3283 return; 3284 } 3285 3286 s->tag = g_strdup(tag); 3287 s->vmstate = g_strdup(vmstate); 3288 s->devices = QAPI_CLONE(strList, devices); 3289 3290 job_start(&s->common); 3291 } 3292 3293 void qmp_snapshot_delete(const char *job_id, 3294 const char *tag, 3295 strList *devices, 3296 Error **errp) 3297 { 3298 SnapshotJob *s; 3299 3300 s = job_create(job_id, &snapshot_delete_job_driver, NULL, 3301 qemu_get_aio_context(), JOB_MANUAL_DISMISS, 3302 NULL, NULL, errp); 3303 if (!s) { 3304 return; 3305 } 3306 3307 s->tag = g_strdup(tag); 3308 s->devices = QAPI_CLONE(strList, devices); 3309 3310 job_start(&s->common); 3311 } 3312