1 /* 2 * QEMU System Emulator 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2009-2015 Red Hat Inc 6 * 7 * Authors: 8 * Juan Quintela <quintela@redhat.com> 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a copy 11 * of this software and associated documentation files (the "Software"), to deal 12 * in the Software without restriction, including without limitation the rights 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 14 * copies of the Software, and to permit persons to whom the Software is 15 * furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 26 * THE SOFTWARE. 27 */ 28 29 #include "qemu/osdep.h" 30 #include "hw/boards.h" 31 #include "hw/hw.h" 32 #include "hw/qdev.h" 33 #include "hw/xen/xen.h" 34 #include "net/net.h" 35 #include "sysemu/sysemu.h" 36 #include "qemu/timer.h" 37 #include "migration/migration.h" 38 #include "qemu-file-channel.h" 39 #include "savevm.h" 40 #include "postcopy-ram.h" 41 #include "qapi/qmp/qerror.h" 42 #include "qemu/error-report.h" 43 #include "qemu/queue.h" 44 #include "sysemu/cpus.h" 45 #include "exec/memory.h" 46 #include "exec/target_page.h" 47 #include "qmp-commands.h" 48 #include "trace.h" 49 #include "qemu/bitops.h" 50 #include "qemu/iov.h" 51 #include "block/snapshot.h" 52 #include "qemu/cutils.h" 53 #include "io/channel-buffer.h" 54 #include "io/channel-file.h" 55 56 #ifndef ETH_P_RARP 57 #define ETH_P_RARP 0x8035 58 #endif 59 #define ARP_HTYPE_ETH 0x0001 60 #define ARP_PTYPE_IP 0x0800 61 #define ARP_OP_REQUEST_REV 0x3 62 63 const unsigned int postcopy_ram_discard_version = 0; 64 65 static bool skip_section_footers; 66 67 /* Subcommands for QEMU_VM_COMMAND */ 68 enum qemu_vm_cmd { 69 MIG_CMD_INVALID = 0, /* Must be 0 */ 70 MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */ 71 MIG_CMD_PING, /* Request a PONG on the RP */ 72 73 MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just 74 warn we might want to do PC */ 75 MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming 76 pages as it's running. */ 77 MIG_CMD_POSTCOPY_RUN, /* Start execution */ 78 79 MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that 80 were previously sent during 81 precopy but are dirty. */ 82 MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */ 83 MIG_CMD_MAX 84 }; 85 86 #define MAX_VM_CMD_PACKAGED_SIZE (1ul << 24) 87 static struct mig_cmd_args { 88 ssize_t len; /* -1 = variable */ 89 const char *name; 90 } mig_cmd_args[] = { 91 [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" }, 92 [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" }, 93 [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" }, 94 [MIG_CMD_POSTCOPY_ADVISE] = { .len = 16, .name = "POSTCOPY_ADVISE" }, 95 [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" }, 96 [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" }, 97 [MIG_CMD_POSTCOPY_RAM_DISCARD] = { 98 .len = -1, .name = "POSTCOPY_RAM_DISCARD" }, 99 [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" }, 100 [MIG_CMD_MAX] = { .len = -1, .name = "MAX" }, 101 }; 102 103 static int announce_self_create(uint8_t *buf, 104 uint8_t *mac_addr) 105 { 106 /* Ethernet header. */ 107 memset(buf, 0xff, 6); /* destination MAC addr */ 108 memcpy(buf + 6, mac_addr, 6); /* source MAC addr */ 109 *(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */ 110 111 /* RARP header. */ 112 *(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */ 113 *(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */ 114 *(buf + 18) = 6; /* hardware addr length (ethernet) */ 115 *(buf + 19) = 4; /* protocol addr length (IPv4) */ 116 *(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */ 117 memcpy(buf + 22, mac_addr, 6); /* source hw addr */ 118 memset(buf + 28, 0x00, 4); /* source protocol addr */ 119 memcpy(buf + 32, mac_addr, 6); /* target hw addr */ 120 memset(buf + 38, 0x00, 4); /* target protocol addr */ 121 122 /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */ 123 memset(buf + 42, 0x00, 18); 124 125 return 60; /* len (FCS will be added by hardware) */ 126 } 127 128 static void qemu_announce_self_iter(NICState *nic, void *opaque) 129 { 130 uint8_t buf[60]; 131 int len; 132 133 trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr)); 134 len = announce_self_create(buf, nic->conf->macaddr.a); 135 136 qemu_send_packet_raw(qemu_get_queue(nic), buf, len); 137 } 138 139 140 static void qemu_announce_self_once(void *opaque) 141 { 142 static int count = SELF_ANNOUNCE_ROUNDS; 143 QEMUTimer *timer = *(QEMUTimer **)opaque; 144 145 qemu_foreach_nic(qemu_announce_self_iter, NULL); 146 147 if (--count) { 148 /* delay 50ms, 150ms, 250ms, ... */ 149 timer_mod(timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + 150 self_announce_delay(count)); 151 } else { 152 timer_del(timer); 153 timer_free(timer); 154 } 155 } 156 157 void qemu_announce_self(void) 158 { 159 static QEMUTimer *timer; 160 timer = timer_new_ms(QEMU_CLOCK_REALTIME, qemu_announce_self_once, &timer); 161 qemu_announce_self_once(&timer); 162 } 163 164 /***********************************************************/ 165 /* savevm/loadvm support */ 166 167 static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, 168 int64_t pos) 169 { 170 int ret; 171 QEMUIOVector qiov; 172 173 qemu_iovec_init_external(&qiov, iov, iovcnt); 174 ret = bdrv_writev_vmstate(opaque, &qiov, pos); 175 if (ret < 0) { 176 return ret; 177 } 178 179 return qiov.size; 180 } 181 182 static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, 183 size_t size) 184 { 185 return bdrv_load_vmstate(opaque, buf, pos, size); 186 } 187 188 static int bdrv_fclose(void *opaque) 189 { 190 return bdrv_flush(opaque); 191 } 192 193 static const QEMUFileOps bdrv_read_ops = { 194 .get_buffer = block_get_buffer, 195 .close = bdrv_fclose 196 }; 197 198 static const QEMUFileOps bdrv_write_ops = { 199 .writev_buffer = block_writev_buffer, 200 .close = bdrv_fclose 201 }; 202 203 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable) 204 { 205 if (is_writable) { 206 return qemu_fopen_ops(bs, &bdrv_write_ops); 207 } 208 return qemu_fopen_ops(bs, &bdrv_read_ops); 209 } 210 211 212 /* QEMUFile timer support. 213 * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c 214 */ 215 216 void timer_put(QEMUFile *f, QEMUTimer *ts) 217 { 218 uint64_t expire_time; 219 220 expire_time = timer_expire_time_ns(ts); 221 qemu_put_be64(f, expire_time); 222 } 223 224 void timer_get(QEMUFile *f, QEMUTimer *ts) 225 { 226 uint64_t expire_time; 227 228 expire_time = qemu_get_be64(f); 229 if (expire_time != -1) { 230 timer_mod_ns(ts, expire_time); 231 } else { 232 timer_del(ts); 233 } 234 } 235 236 237 /* VMState timer support. 238 * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c 239 */ 240 241 static int get_timer(QEMUFile *f, void *pv, size_t size, VMStateField *field) 242 { 243 QEMUTimer *v = pv; 244 timer_get(f, v); 245 return 0; 246 } 247 248 static int put_timer(QEMUFile *f, void *pv, size_t size, VMStateField *field, 249 QJSON *vmdesc) 250 { 251 QEMUTimer *v = pv; 252 timer_put(f, v); 253 254 return 0; 255 } 256 257 const VMStateInfo vmstate_info_timer = { 258 .name = "timer", 259 .get = get_timer, 260 .put = put_timer, 261 }; 262 263 264 typedef struct CompatEntry { 265 char idstr[256]; 266 int instance_id; 267 } CompatEntry; 268 269 typedef struct SaveStateEntry { 270 QTAILQ_ENTRY(SaveStateEntry) entry; 271 char idstr[256]; 272 int instance_id; 273 int alias_id; 274 int version_id; 275 int section_id; 276 SaveVMHandlers *ops; 277 const VMStateDescription *vmsd; 278 void *opaque; 279 CompatEntry *compat; 280 int is_ram; 281 } SaveStateEntry; 282 283 typedef struct SaveState { 284 QTAILQ_HEAD(, SaveStateEntry) handlers; 285 int global_section_id; 286 bool skip_configuration; 287 uint32_t len; 288 const char *name; 289 uint32_t target_page_bits; 290 } SaveState; 291 292 static SaveState savevm_state = { 293 .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers), 294 .global_section_id = 0, 295 .skip_configuration = false, 296 }; 297 298 void savevm_skip_configuration(void) 299 { 300 savevm_state.skip_configuration = true; 301 } 302 303 304 static void configuration_pre_save(void *opaque) 305 { 306 SaveState *state = opaque; 307 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 308 309 state->len = strlen(current_name); 310 state->name = current_name; 311 state->target_page_bits = qemu_target_page_bits(); 312 } 313 314 static int configuration_pre_load(void *opaque) 315 { 316 SaveState *state = opaque; 317 318 /* If there is no target-page-bits subsection it means the source 319 * predates the variable-target-page-bits support and is using the 320 * minimum possible value for this CPU. 321 */ 322 state->target_page_bits = qemu_target_page_bits_min(); 323 return 0; 324 } 325 326 static int configuration_post_load(void *opaque, int version_id) 327 { 328 SaveState *state = opaque; 329 const char *current_name = MACHINE_GET_CLASS(current_machine)->name; 330 331 if (strncmp(state->name, current_name, state->len) != 0) { 332 error_report("Machine type received is '%.*s' and local is '%s'", 333 (int) state->len, state->name, current_name); 334 return -EINVAL; 335 } 336 337 if (state->target_page_bits != qemu_target_page_bits()) { 338 error_report("Received TARGET_PAGE_BITS is %d but local is %d", 339 state->target_page_bits, qemu_target_page_bits()); 340 return -EINVAL; 341 } 342 343 return 0; 344 } 345 346 /* The target-page-bits subsection is present only if the 347 * target page size is not the same as the default (ie the 348 * minimum page size for a variable-page-size guest CPU). 349 * If it is present then it contains the actual target page 350 * bits for the machine, and migration will fail if the 351 * two ends don't agree about it. 352 */ 353 static bool vmstate_target_page_bits_needed(void *opaque) 354 { 355 return qemu_target_page_bits() 356 > qemu_target_page_bits_min(); 357 } 358 359 static const VMStateDescription vmstate_target_page_bits = { 360 .name = "configuration/target-page-bits", 361 .version_id = 1, 362 .minimum_version_id = 1, 363 .needed = vmstate_target_page_bits_needed, 364 .fields = (VMStateField[]) { 365 VMSTATE_UINT32(target_page_bits, SaveState), 366 VMSTATE_END_OF_LIST() 367 } 368 }; 369 370 static const VMStateDescription vmstate_configuration = { 371 .name = "configuration", 372 .version_id = 1, 373 .pre_load = configuration_pre_load, 374 .post_load = configuration_post_load, 375 .pre_save = configuration_pre_save, 376 .fields = (VMStateField[]) { 377 VMSTATE_UINT32(len, SaveState), 378 VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len), 379 VMSTATE_END_OF_LIST() 380 }, 381 .subsections = (const VMStateDescription*[]) { 382 &vmstate_target_page_bits, 383 NULL 384 } 385 }; 386 387 static void dump_vmstate_vmsd(FILE *out_file, 388 const VMStateDescription *vmsd, int indent, 389 bool is_subsection); 390 391 static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field, 392 int indent) 393 { 394 fprintf(out_file, "%*s{\n", indent, ""); 395 indent += 2; 396 fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name); 397 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 398 field->version_id); 399 fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "", 400 field->field_exists ? "true" : "false"); 401 fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size); 402 if (field->vmsd != NULL) { 403 fprintf(out_file, ",\n"); 404 dump_vmstate_vmsd(out_file, field->vmsd, indent, false); 405 } 406 fprintf(out_file, "\n%*s}", indent - 2, ""); 407 } 408 409 static void dump_vmstate_vmss(FILE *out_file, 410 const VMStateDescription **subsection, 411 int indent) 412 { 413 if (*subsection != NULL) { 414 dump_vmstate_vmsd(out_file, *subsection, indent, true); 415 } 416 } 417 418 static void dump_vmstate_vmsd(FILE *out_file, 419 const VMStateDescription *vmsd, int indent, 420 bool is_subsection) 421 { 422 if (is_subsection) { 423 fprintf(out_file, "%*s{\n", indent, ""); 424 } else { 425 fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description"); 426 } 427 indent += 2; 428 fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name); 429 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 430 vmsd->version_id); 431 fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "", 432 vmsd->minimum_version_id); 433 if (vmsd->fields != NULL) { 434 const VMStateField *field = vmsd->fields; 435 bool first; 436 437 fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, ""); 438 first = true; 439 while (field->name != NULL) { 440 if (field->flags & VMS_MUST_EXIST) { 441 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */ 442 field++; 443 continue; 444 } 445 if (!first) { 446 fprintf(out_file, ",\n"); 447 } 448 dump_vmstate_vmsf(out_file, field, indent + 2); 449 field++; 450 first = false; 451 } 452 fprintf(out_file, "\n%*s]", indent, ""); 453 } 454 if (vmsd->subsections != NULL) { 455 const VMStateDescription **subsection = vmsd->subsections; 456 bool first; 457 458 fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, ""); 459 first = true; 460 while (*subsection != NULL) { 461 if (!first) { 462 fprintf(out_file, ",\n"); 463 } 464 dump_vmstate_vmss(out_file, subsection, indent + 2); 465 subsection++; 466 first = false; 467 } 468 fprintf(out_file, "\n%*s]", indent, ""); 469 } 470 fprintf(out_file, "\n%*s}", indent - 2, ""); 471 } 472 473 static void dump_machine_type(FILE *out_file) 474 { 475 MachineClass *mc; 476 477 mc = MACHINE_GET_CLASS(current_machine); 478 479 fprintf(out_file, " \"vmschkmachine\": {\n"); 480 fprintf(out_file, " \"Name\": \"%s\"\n", mc->name); 481 fprintf(out_file, " },\n"); 482 } 483 484 void dump_vmstate_json_to_file(FILE *out_file) 485 { 486 GSList *list, *elt; 487 bool first; 488 489 fprintf(out_file, "{\n"); 490 dump_machine_type(out_file); 491 492 first = true; 493 list = object_class_get_list(TYPE_DEVICE, true); 494 for (elt = list; elt; elt = elt->next) { 495 DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data, 496 TYPE_DEVICE); 497 const char *name; 498 int indent = 2; 499 500 if (!dc->vmsd) { 501 continue; 502 } 503 504 if (!first) { 505 fprintf(out_file, ",\n"); 506 } 507 name = object_class_get_name(OBJECT_CLASS(dc)); 508 fprintf(out_file, "%*s\"%s\": {\n", indent, "", name); 509 indent += 2; 510 fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name); 511 fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "", 512 dc->vmsd->version_id); 513 fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "", 514 dc->vmsd->minimum_version_id); 515 516 dump_vmstate_vmsd(out_file, dc->vmsd, indent, false); 517 518 fprintf(out_file, "\n%*s}", indent - 2, ""); 519 first = false; 520 } 521 fprintf(out_file, "\n}\n"); 522 fclose(out_file); 523 } 524 525 static int calculate_new_instance_id(const char *idstr) 526 { 527 SaveStateEntry *se; 528 int instance_id = 0; 529 530 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 531 if (strcmp(idstr, se->idstr) == 0 532 && instance_id <= se->instance_id) { 533 instance_id = se->instance_id + 1; 534 } 535 } 536 return instance_id; 537 } 538 539 static int calculate_compat_instance_id(const char *idstr) 540 { 541 SaveStateEntry *se; 542 int instance_id = 0; 543 544 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 545 if (!se->compat) { 546 continue; 547 } 548 549 if (strcmp(idstr, se->compat->idstr) == 0 550 && instance_id <= se->compat->instance_id) { 551 instance_id = se->compat->instance_id + 1; 552 } 553 } 554 return instance_id; 555 } 556 557 static inline MigrationPriority save_state_priority(SaveStateEntry *se) 558 { 559 if (se->vmsd) { 560 return se->vmsd->priority; 561 } 562 return MIG_PRI_DEFAULT; 563 } 564 565 static void savevm_state_handler_insert(SaveStateEntry *nse) 566 { 567 MigrationPriority priority = save_state_priority(nse); 568 SaveStateEntry *se; 569 570 assert(priority <= MIG_PRI_MAX); 571 572 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 573 if (save_state_priority(se) < priority) { 574 break; 575 } 576 } 577 578 if (se) { 579 QTAILQ_INSERT_BEFORE(se, nse, entry); 580 } else { 581 QTAILQ_INSERT_TAIL(&savevm_state.handlers, nse, entry); 582 } 583 } 584 585 /* TODO: Individual devices generally have very little idea about the rest 586 of the system, so instance_id should be removed/replaced. 587 Meanwhile pass -1 as instance_id if you do not already have a clearly 588 distinguishing id for all instances of your device class. */ 589 int register_savevm_live(DeviceState *dev, 590 const char *idstr, 591 int instance_id, 592 int version_id, 593 SaveVMHandlers *ops, 594 void *opaque) 595 { 596 SaveStateEntry *se; 597 598 se = g_new0(SaveStateEntry, 1); 599 se->version_id = version_id; 600 se->section_id = savevm_state.global_section_id++; 601 se->ops = ops; 602 se->opaque = opaque; 603 se->vmsd = NULL; 604 /* if this is a live_savem then set is_ram */ 605 if (ops->save_live_setup != NULL) { 606 se->is_ram = 1; 607 } 608 609 if (dev) { 610 char *id = qdev_get_dev_path(dev); 611 if (id) { 612 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 613 sizeof(se->idstr)) { 614 error_report("Path too long for VMState (%s)", id); 615 g_free(id); 616 g_free(se); 617 618 return -1; 619 } 620 g_free(id); 621 622 se->compat = g_new0(CompatEntry, 1); 623 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr); 624 se->compat->instance_id = instance_id == -1 ? 625 calculate_compat_instance_id(idstr) : instance_id; 626 instance_id = -1; 627 } 628 } 629 pstrcat(se->idstr, sizeof(se->idstr), idstr); 630 631 if (instance_id == -1) { 632 se->instance_id = calculate_new_instance_id(se->idstr); 633 } else { 634 se->instance_id = instance_id; 635 } 636 assert(!se->compat || se->instance_id == 0); 637 savevm_state_handler_insert(se); 638 return 0; 639 } 640 641 int register_savevm(DeviceState *dev, 642 const char *idstr, 643 int instance_id, 644 int version_id, 645 SaveStateHandler *save_state, 646 LoadStateHandler *load_state, 647 void *opaque) 648 { 649 SaveVMHandlers *ops = g_new0(SaveVMHandlers, 1); 650 ops->save_state = save_state; 651 ops->load_state = load_state; 652 return register_savevm_live(dev, idstr, instance_id, version_id, 653 ops, opaque); 654 } 655 656 void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque) 657 { 658 SaveStateEntry *se, *new_se; 659 char id[256] = ""; 660 661 if (dev) { 662 char *path = qdev_get_dev_path(dev); 663 if (path) { 664 pstrcpy(id, sizeof(id), path); 665 pstrcat(id, sizeof(id), "/"); 666 g_free(path); 667 } 668 } 669 pstrcat(id, sizeof(id), idstr); 670 671 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 672 if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) { 673 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 674 g_free(se->compat); 675 g_free(se->ops); 676 g_free(se); 677 } 678 } 679 } 680 681 int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, 682 const VMStateDescription *vmsd, 683 void *opaque, int alias_id, 684 int required_for_version, 685 Error **errp) 686 { 687 SaveStateEntry *se; 688 689 /* If this triggers, alias support can be dropped for the vmsd. */ 690 assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id); 691 692 se = g_new0(SaveStateEntry, 1); 693 se->version_id = vmsd->version_id; 694 se->section_id = savevm_state.global_section_id++; 695 se->opaque = opaque; 696 se->vmsd = vmsd; 697 se->alias_id = alias_id; 698 699 if (dev) { 700 char *id = qdev_get_dev_path(dev); 701 if (id) { 702 if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= 703 sizeof(se->idstr)) { 704 error_setg(errp, "Path too long for VMState (%s)", id); 705 g_free(id); 706 g_free(se); 707 708 return -1; 709 } 710 g_free(id); 711 712 se->compat = g_new0(CompatEntry, 1); 713 pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name); 714 se->compat->instance_id = instance_id == -1 ? 715 calculate_compat_instance_id(vmsd->name) : instance_id; 716 instance_id = -1; 717 } 718 } 719 pstrcat(se->idstr, sizeof(se->idstr), vmsd->name); 720 721 if (instance_id == -1) { 722 se->instance_id = calculate_new_instance_id(se->idstr); 723 } else { 724 se->instance_id = instance_id; 725 } 726 assert(!se->compat || se->instance_id == 0); 727 savevm_state_handler_insert(se); 728 return 0; 729 } 730 731 void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd, 732 void *opaque) 733 { 734 SaveStateEntry *se, *new_se; 735 736 QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) { 737 if (se->vmsd == vmsd && se->opaque == opaque) { 738 QTAILQ_REMOVE(&savevm_state.handlers, se, entry); 739 g_free(se->compat); 740 g_free(se); 741 } 742 } 743 } 744 745 static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id) 746 { 747 trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 748 if (!se->vmsd) { /* Old style */ 749 return se->ops->load_state(f, se->opaque, version_id); 750 } 751 return vmstate_load_state(f, se->vmsd, se->opaque, version_id); 752 } 753 754 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc) 755 { 756 int64_t old_offset, size; 757 758 old_offset = qemu_ftell_fast(f); 759 se->ops->save_state(f, se->opaque); 760 size = qemu_ftell_fast(f) - old_offset; 761 762 if (vmdesc) { 763 json_prop_int(vmdesc, "size", size); 764 json_start_array(vmdesc, "fields"); 765 json_start_object(vmdesc, NULL); 766 json_prop_str(vmdesc, "name", "data"); 767 json_prop_int(vmdesc, "size", size); 768 json_prop_str(vmdesc, "type", "buffer"); 769 json_end_object(vmdesc); 770 json_end_array(vmdesc); 771 } 772 } 773 774 static void vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc) 775 { 776 trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); 777 if (!se->vmsd) { 778 vmstate_save_old_style(f, se, vmdesc); 779 return; 780 } 781 vmstate_save_state(f, se->vmsd, se->opaque, vmdesc); 782 } 783 784 void savevm_skip_section_footers(void) 785 { 786 skip_section_footers = true; 787 } 788 789 /* 790 * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL) 791 */ 792 static void save_section_header(QEMUFile *f, SaveStateEntry *se, 793 uint8_t section_type) 794 { 795 qemu_put_byte(f, section_type); 796 qemu_put_be32(f, se->section_id); 797 798 if (section_type == QEMU_VM_SECTION_FULL || 799 section_type == QEMU_VM_SECTION_START) { 800 /* ID string */ 801 size_t len = strlen(se->idstr); 802 qemu_put_byte(f, len); 803 qemu_put_buffer(f, (uint8_t *)se->idstr, len); 804 805 qemu_put_be32(f, se->instance_id); 806 qemu_put_be32(f, se->version_id); 807 } 808 } 809 810 /* 811 * Write a footer onto device sections that catches cases misformatted device 812 * sections. 813 */ 814 static void save_section_footer(QEMUFile *f, SaveStateEntry *se) 815 { 816 if (!skip_section_footers) { 817 qemu_put_byte(f, QEMU_VM_SECTION_FOOTER); 818 qemu_put_be32(f, se->section_id); 819 } 820 } 821 822 /** 823 * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the 824 * command and associated data. 825 * 826 * @f: File to send command on 827 * @command: Command type to send 828 * @len: Length of associated data 829 * @data: Data associated with command. 830 */ 831 static void qemu_savevm_command_send(QEMUFile *f, 832 enum qemu_vm_cmd command, 833 uint16_t len, 834 uint8_t *data) 835 { 836 trace_savevm_command_send(command, len); 837 qemu_put_byte(f, QEMU_VM_COMMAND); 838 qemu_put_be16(f, (uint16_t)command); 839 qemu_put_be16(f, len); 840 qemu_put_buffer(f, data, len); 841 qemu_fflush(f); 842 } 843 844 void qemu_savevm_send_ping(QEMUFile *f, uint32_t value) 845 { 846 uint32_t buf; 847 848 trace_savevm_send_ping(value); 849 buf = cpu_to_be32(value); 850 qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf); 851 } 852 853 void qemu_savevm_send_open_return_path(QEMUFile *f) 854 { 855 trace_savevm_send_open_return_path(); 856 qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL); 857 } 858 859 /* We have a buffer of data to send; we don't want that all to be loaded 860 * by the command itself, so the command contains just the length of the 861 * extra buffer that we then send straight after it. 862 * TODO: Must be a better way to organise that 863 * 864 * Returns: 865 * 0 on success 866 * -ve on error 867 */ 868 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len) 869 { 870 uint32_t tmp; 871 872 if (len > MAX_VM_CMD_PACKAGED_SIZE) { 873 error_report("%s: Unreasonably large packaged state: %zu", 874 __func__, len); 875 return -1; 876 } 877 878 tmp = cpu_to_be32(len); 879 880 trace_qemu_savevm_send_packaged(); 881 qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp); 882 883 qemu_put_buffer(f, buf, len); 884 885 return 0; 886 } 887 888 /* Send prior to any postcopy transfer */ 889 void qemu_savevm_send_postcopy_advise(QEMUFile *f) 890 { 891 uint64_t tmp[2]; 892 tmp[0] = cpu_to_be64(ram_pagesize_summary()); 893 tmp[1] = cpu_to_be64(qemu_target_page_size()); 894 895 trace_qemu_savevm_send_postcopy_advise(); 896 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 16, (uint8_t *)tmp); 897 } 898 899 /* Sent prior to starting the destination running in postcopy, discard pages 900 * that have already been sent but redirtied on the source. 901 * CMD_POSTCOPY_RAM_DISCARD consist of: 902 * byte version (0) 903 * byte Length of name field (not including 0) 904 * n x byte RAM block name 905 * byte 0 terminator (just for safety) 906 * n x Byte ranges within the named RAMBlock 907 * be64 Start of the range 908 * be64 Length 909 * 910 * name: RAMBlock name that these entries are part of 911 * len: Number of page entries 912 * start_list: 'len' addresses 913 * length_list: 'len' addresses 914 * 915 */ 916 void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name, 917 uint16_t len, 918 uint64_t *start_list, 919 uint64_t *length_list) 920 { 921 uint8_t *buf; 922 uint16_t tmplen; 923 uint16_t t; 924 size_t name_len = strlen(name); 925 926 trace_qemu_savevm_send_postcopy_ram_discard(name, len); 927 assert(name_len < 256); 928 buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len); 929 buf[0] = postcopy_ram_discard_version; 930 buf[1] = name_len; 931 memcpy(buf + 2, name, name_len); 932 tmplen = 2 + name_len; 933 buf[tmplen++] = '\0'; 934 935 for (t = 0; t < len; t++) { 936 stq_be_p(buf + tmplen, start_list[t]); 937 tmplen += 8; 938 stq_be_p(buf + tmplen, length_list[t]); 939 tmplen += 8; 940 } 941 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf); 942 g_free(buf); 943 } 944 945 /* Get the destination into a state where it can receive postcopy data. */ 946 void qemu_savevm_send_postcopy_listen(QEMUFile *f) 947 { 948 trace_savevm_send_postcopy_listen(); 949 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL); 950 } 951 952 /* Kick the destination into running */ 953 void qemu_savevm_send_postcopy_run(QEMUFile *f) 954 { 955 trace_savevm_send_postcopy_run(); 956 qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL); 957 } 958 959 bool qemu_savevm_state_blocked(Error **errp) 960 { 961 SaveStateEntry *se; 962 963 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 964 if (se->vmsd && se->vmsd->unmigratable) { 965 error_setg(errp, "State blocked by non-migratable device '%s'", 966 se->idstr); 967 return true; 968 } 969 } 970 return false; 971 } 972 973 static bool enforce_config_section(void) 974 { 975 MachineState *machine = MACHINE(qdev_get_machine()); 976 return machine->enforce_config_section; 977 } 978 979 void qemu_savevm_state_header(QEMUFile *f) 980 { 981 trace_savevm_state_header(); 982 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 983 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 984 985 if (!savevm_state.skip_configuration || enforce_config_section()) { 986 qemu_put_byte(f, QEMU_VM_CONFIGURATION); 987 vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0); 988 } 989 990 } 991 992 void qemu_savevm_state_begin(QEMUFile *f) 993 { 994 SaveStateEntry *se; 995 int ret; 996 997 trace_savevm_state_begin(); 998 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 999 if (!se->ops || !se->ops->save_live_setup) { 1000 continue; 1001 } 1002 if (se->ops && se->ops->is_active) { 1003 if (!se->ops->is_active(se->opaque)) { 1004 continue; 1005 } 1006 } 1007 save_section_header(f, se, QEMU_VM_SECTION_START); 1008 1009 ret = se->ops->save_live_setup(f, se->opaque); 1010 save_section_footer(f, se); 1011 if (ret < 0) { 1012 qemu_file_set_error(f, ret); 1013 break; 1014 } 1015 } 1016 } 1017 1018 /* 1019 * this function has three return values: 1020 * negative: there was one error, and we have -errno. 1021 * 0 : We haven't finished, caller have to go again 1022 * 1 : We have finished, we can go to complete phase 1023 */ 1024 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy) 1025 { 1026 SaveStateEntry *se; 1027 int ret = 1; 1028 1029 trace_savevm_state_iterate(); 1030 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1031 if (!se->ops || !se->ops->save_live_iterate) { 1032 continue; 1033 } 1034 if (se->ops && se->ops->is_active) { 1035 if (!se->ops->is_active(se->opaque)) { 1036 continue; 1037 } 1038 } 1039 /* 1040 * In the postcopy phase, any device that doesn't know how to 1041 * do postcopy should have saved it's state in the _complete 1042 * call that's already run, it might get confused if we call 1043 * iterate afterwards. 1044 */ 1045 if (postcopy && !se->ops->save_live_complete_postcopy) { 1046 continue; 1047 } 1048 if (qemu_file_rate_limit(f)) { 1049 return 0; 1050 } 1051 trace_savevm_section_start(se->idstr, se->section_id); 1052 1053 save_section_header(f, se, QEMU_VM_SECTION_PART); 1054 1055 ret = se->ops->save_live_iterate(f, se->opaque); 1056 trace_savevm_section_end(se->idstr, se->section_id, ret); 1057 save_section_footer(f, se); 1058 1059 if (ret < 0) { 1060 qemu_file_set_error(f, ret); 1061 } 1062 if (ret <= 0) { 1063 /* Do not proceed to the next vmstate before this one reported 1064 completion of the current stage. This serializes the migration 1065 and reduces the probability that a faster changing state is 1066 synchronized over and over again. */ 1067 break; 1068 } 1069 } 1070 return ret; 1071 } 1072 1073 static bool should_send_vmdesc(void) 1074 { 1075 MachineState *machine = MACHINE(qdev_get_machine()); 1076 bool in_postcopy = migration_in_postcopy(); 1077 return !machine->suppress_vmdesc && !in_postcopy; 1078 } 1079 1080 /* 1081 * Calls the save_live_complete_postcopy methods 1082 * causing the last few pages to be sent immediately and doing any associated 1083 * cleanup. 1084 * Note postcopy also calls qemu_savevm_state_complete_precopy to complete 1085 * all the other devices, but that happens at the point we switch to postcopy. 1086 */ 1087 void qemu_savevm_state_complete_postcopy(QEMUFile *f) 1088 { 1089 SaveStateEntry *se; 1090 int ret; 1091 1092 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1093 if (!se->ops || !se->ops->save_live_complete_postcopy) { 1094 continue; 1095 } 1096 if (se->ops && se->ops->is_active) { 1097 if (!se->ops->is_active(se->opaque)) { 1098 continue; 1099 } 1100 } 1101 trace_savevm_section_start(se->idstr, se->section_id); 1102 /* Section type */ 1103 qemu_put_byte(f, QEMU_VM_SECTION_END); 1104 qemu_put_be32(f, se->section_id); 1105 1106 ret = se->ops->save_live_complete_postcopy(f, se->opaque); 1107 trace_savevm_section_end(se->idstr, se->section_id, ret); 1108 save_section_footer(f, se); 1109 if (ret < 0) { 1110 qemu_file_set_error(f, ret); 1111 return; 1112 } 1113 } 1114 1115 qemu_put_byte(f, QEMU_VM_EOF); 1116 qemu_fflush(f); 1117 } 1118 1119 void qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only) 1120 { 1121 QJSON *vmdesc; 1122 int vmdesc_len; 1123 SaveStateEntry *se; 1124 int ret; 1125 bool in_postcopy = migration_in_postcopy(); 1126 1127 trace_savevm_state_complete_precopy(); 1128 1129 cpu_synchronize_all_states(); 1130 1131 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1132 if (!se->ops || 1133 (in_postcopy && se->ops->save_live_complete_postcopy) || 1134 (in_postcopy && !iterable_only) || 1135 !se->ops->save_live_complete_precopy) { 1136 continue; 1137 } 1138 1139 if (se->ops && se->ops->is_active) { 1140 if (!se->ops->is_active(se->opaque)) { 1141 continue; 1142 } 1143 } 1144 trace_savevm_section_start(se->idstr, se->section_id); 1145 1146 save_section_header(f, se, QEMU_VM_SECTION_END); 1147 1148 ret = se->ops->save_live_complete_precopy(f, se->opaque); 1149 trace_savevm_section_end(se->idstr, se->section_id, ret); 1150 save_section_footer(f, se); 1151 if (ret < 0) { 1152 qemu_file_set_error(f, ret); 1153 return; 1154 } 1155 } 1156 1157 if (iterable_only) { 1158 return; 1159 } 1160 1161 vmdesc = qjson_new(); 1162 json_prop_int(vmdesc, "page_size", qemu_target_page_size()); 1163 json_start_array(vmdesc, "devices"); 1164 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1165 1166 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1167 continue; 1168 } 1169 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1170 trace_savevm_section_skip(se->idstr, se->section_id); 1171 continue; 1172 } 1173 1174 trace_savevm_section_start(se->idstr, se->section_id); 1175 1176 json_start_object(vmdesc, NULL); 1177 json_prop_str(vmdesc, "name", se->idstr); 1178 json_prop_int(vmdesc, "instance_id", se->instance_id); 1179 1180 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1181 vmstate_save(f, se, vmdesc); 1182 trace_savevm_section_end(se->idstr, se->section_id, 0); 1183 save_section_footer(f, se); 1184 1185 json_end_object(vmdesc); 1186 } 1187 1188 if (!in_postcopy) { 1189 /* Postcopy stream will still be going */ 1190 qemu_put_byte(f, QEMU_VM_EOF); 1191 } 1192 1193 json_end_array(vmdesc); 1194 qjson_finish(vmdesc); 1195 vmdesc_len = strlen(qjson_get_str(vmdesc)); 1196 1197 if (should_send_vmdesc()) { 1198 qemu_put_byte(f, QEMU_VM_VMDESCRIPTION); 1199 qemu_put_be32(f, vmdesc_len); 1200 qemu_put_buffer(f, (uint8_t *)qjson_get_str(vmdesc), vmdesc_len); 1201 } 1202 qjson_destroy(vmdesc); 1203 1204 qemu_fflush(f); 1205 } 1206 1207 /* Give an estimate of the amount left to be transferred, 1208 * the result is split into the amount for units that can and 1209 * for units that can't do postcopy. 1210 */ 1211 void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size, 1212 uint64_t *res_non_postcopiable, 1213 uint64_t *res_postcopiable) 1214 { 1215 SaveStateEntry *se; 1216 1217 *res_non_postcopiable = 0; 1218 *res_postcopiable = 0; 1219 1220 1221 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1222 if (!se->ops || !se->ops->save_live_pending) { 1223 continue; 1224 } 1225 if (se->ops && se->ops->is_active) { 1226 if (!se->ops->is_active(se->opaque)) { 1227 continue; 1228 } 1229 } 1230 se->ops->save_live_pending(f, se->opaque, threshold_size, 1231 res_non_postcopiable, res_postcopiable); 1232 } 1233 } 1234 1235 void qemu_savevm_state_cleanup(void) 1236 { 1237 SaveStateEntry *se; 1238 1239 trace_savevm_state_cleanup(); 1240 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1241 if (se->ops && se->ops->cleanup) { 1242 se->ops->cleanup(se->opaque); 1243 } 1244 } 1245 } 1246 1247 static int qemu_savevm_state(QEMUFile *f, Error **errp) 1248 { 1249 int ret; 1250 MigrationState *ms = migrate_init(); 1251 MigrationStatus status; 1252 ms->to_dst_file = f; 1253 1254 if (migration_is_blocked(errp)) { 1255 ret = -EINVAL; 1256 goto done; 1257 } 1258 1259 if (migrate_use_block()) { 1260 error_setg(errp, "Block migration and snapshots are incompatible"); 1261 ret = -EINVAL; 1262 goto done; 1263 } 1264 1265 qemu_mutex_unlock_iothread(); 1266 qemu_savevm_state_header(f); 1267 qemu_savevm_state_begin(f); 1268 qemu_mutex_lock_iothread(); 1269 1270 while (qemu_file_get_error(f) == 0) { 1271 if (qemu_savevm_state_iterate(f, false) > 0) { 1272 break; 1273 } 1274 } 1275 1276 ret = qemu_file_get_error(f); 1277 if (ret == 0) { 1278 qemu_savevm_state_complete_precopy(f, false); 1279 ret = qemu_file_get_error(f); 1280 } 1281 qemu_savevm_state_cleanup(); 1282 if (ret != 0) { 1283 error_setg_errno(errp, -ret, "Error while writing VM state"); 1284 } 1285 1286 done: 1287 if (ret != 0) { 1288 status = MIGRATION_STATUS_FAILED; 1289 } else { 1290 status = MIGRATION_STATUS_COMPLETED; 1291 } 1292 migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status); 1293 1294 /* f is outer parameter, it should not stay in global migration state after 1295 * this function finished */ 1296 ms->to_dst_file = NULL; 1297 1298 return ret; 1299 } 1300 1301 static int qemu_save_device_state(QEMUFile *f) 1302 { 1303 SaveStateEntry *se; 1304 1305 qemu_put_be32(f, QEMU_VM_FILE_MAGIC); 1306 qemu_put_be32(f, QEMU_VM_FILE_VERSION); 1307 1308 cpu_synchronize_all_states(); 1309 1310 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1311 if (se->is_ram) { 1312 continue; 1313 } 1314 if ((!se->ops || !se->ops->save_state) && !se->vmsd) { 1315 continue; 1316 } 1317 if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { 1318 continue; 1319 } 1320 1321 save_section_header(f, se, QEMU_VM_SECTION_FULL); 1322 1323 vmstate_save(f, se, NULL); 1324 1325 save_section_footer(f, se); 1326 } 1327 1328 qemu_put_byte(f, QEMU_VM_EOF); 1329 1330 return qemu_file_get_error(f); 1331 } 1332 1333 static SaveStateEntry *find_se(const char *idstr, int instance_id) 1334 { 1335 SaveStateEntry *se; 1336 1337 QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { 1338 if (!strcmp(se->idstr, idstr) && 1339 (instance_id == se->instance_id || 1340 instance_id == se->alias_id)) 1341 return se; 1342 /* Migrating from an older version? */ 1343 if (strstr(se->idstr, idstr) && se->compat) { 1344 if (!strcmp(se->compat->idstr, idstr) && 1345 (instance_id == se->compat->instance_id || 1346 instance_id == se->alias_id)) 1347 return se; 1348 } 1349 } 1350 return NULL; 1351 } 1352 1353 enum LoadVMExitCodes { 1354 /* Allow a command to quit all layers of nested loadvm loops */ 1355 LOADVM_QUIT = 1, 1356 }; 1357 1358 static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis); 1359 1360 /* ------ incoming postcopy messages ------ */ 1361 /* 'advise' arrives before any transfers just to tell us that a postcopy 1362 * *might* happen - it might be skipped if precopy transferred everything 1363 * quickly. 1364 */ 1365 static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis) 1366 { 1367 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1368 uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps; 1369 1370 trace_loadvm_postcopy_handle_advise(); 1371 if (ps != POSTCOPY_INCOMING_NONE) { 1372 error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps); 1373 return -1; 1374 } 1375 1376 if (!postcopy_ram_supported_by_host()) { 1377 postcopy_state_set(POSTCOPY_INCOMING_NONE); 1378 return -1; 1379 } 1380 1381 remote_pagesize_summary = qemu_get_be64(mis->from_src_file); 1382 local_pagesize_summary = ram_pagesize_summary(); 1383 1384 if (remote_pagesize_summary != local_pagesize_summary) { 1385 /* 1386 * This detects two potential causes of mismatch: 1387 * a) A mismatch in host page sizes 1388 * Some combinations of mismatch are probably possible but it gets 1389 * a bit more complicated. In particular we need to place whole 1390 * host pages on the dest at once, and we need to ensure that we 1391 * handle dirtying to make sure we never end up sending part of 1392 * a hostpage on it's own. 1393 * b) The use of different huge page sizes on source/destination 1394 * a more fine grain test is performed during RAM block migration 1395 * but this test here causes a nice early clear failure, and 1396 * also fails when passed to an older qemu that doesn't 1397 * do huge pages. 1398 */ 1399 error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64 1400 " d=%" PRIx64 ")", 1401 remote_pagesize_summary, local_pagesize_summary); 1402 return -1; 1403 } 1404 1405 remote_tps = qemu_get_be64(mis->from_src_file); 1406 if (remote_tps != qemu_target_page_size()) { 1407 /* 1408 * Again, some differences could be dealt with, but for now keep it 1409 * simple. 1410 */ 1411 error_report("Postcopy needs matching target page sizes (s=%d d=%zd)", 1412 (int)remote_tps, qemu_target_page_size()); 1413 return -1; 1414 } 1415 1416 if (ram_postcopy_incoming_init(mis)) { 1417 return -1; 1418 } 1419 1420 postcopy_state_set(POSTCOPY_INCOMING_ADVISE); 1421 1422 return 0; 1423 } 1424 1425 /* After postcopy we will be told to throw some pages away since they're 1426 * dirty and will have to be demand fetched. Must happen before CPU is 1427 * started. 1428 * There can be 0..many of these messages, each encoding multiple pages. 1429 */ 1430 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis, 1431 uint16_t len) 1432 { 1433 int tmp; 1434 char ramid[256]; 1435 PostcopyState ps = postcopy_state_get(); 1436 1437 trace_loadvm_postcopy_ram_handle_discard(); 1438 1439 switch (ps) { 1440 case POSTCOPY_INCOMING_ADVISE: 1441 /* 1st discard */ 1442 tmp = postcopy_ram_prepare_discard(mis); 1443 if (tmp) { 1444 return tmp; 1445 } 1446 break; 1447 1448 case POSTCOPY_INCOMING_DISCARD: 1449 /* Expected state */ 1450 break; 1451 1452 default: 1453 error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)", 1454 ps); 1455 return -1; 1456 } 1457 /* We're expecting a 1458 * Version (0) 1459 * a RAM ID string (length byte, name, 0 term) 1460 * then at least 1 16 byte chunk 1461 */ 1462 if (len < (1 + 1 + 1 + 1 + 2 * 8)) { 1463 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1464 return -1; 1465 } 1466 1467 tmp = qemu_get_byte(mis->from_src_file); 1468 if (tmp != postcopy_ram_discard_version) { 1469 error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp); 1470 return -1; 1471 } 1472 1473 if (!qemu_get_counted_string(mis->from_src_file, ramid)) { 1474 error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID"); 1475 return -1; 1476 } 1477 tmp = qemu_get_byte(mis->from_src_file); 1478 if (tmp != 0) { 1479 error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp); 1480 return -1; 1481 } 1482 1483 len -= 3 + strlen(ramid); 1484 if (len % 16) { 1485 error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len); 1486 return -1; 1487 } 1488 trace_loadvm_postcopy_ram_handle_discard_header(ramid, len); 1489 while (len) { 1490 uint64_t start_addr, block_length; 1491 start_addr = qemu_get_be64(mis->from_src_file); 1492 block_length = qemu_get_be64(mis->from_src_file); 1493 1494 len -= 16; 1495 int ret = ram_discard_range(ramid, start_addr, block_length); 1496 if (ret) { 1497 return ret; 1498 } 1499 } 1500 trace_loadvm_postcopy_ram_handle_discard_end(); 1501 1502 return 0; 1503 } 1504 1505 /* 1506 * Triggered by a postcopy_listen command; this thread takes over reading 1507 * the input stream, leaving the main thread free to carry on loading the rest 1508 * of the device state (from RAM). 1509 * (TODO:This could do with being in a postcopy file - but there again it's 1510 * just another input loop, not that postcopy specific) 1511 */ 1512 static void *postcopy_ram_listen_thread(void *opaque) 1513 { 1514 QEMUFile *f = opaque; 1515 MigrationIncomingState *mis = migration_incoming_get_current(); 1516 int load_res; 1517 1518 migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, 1519 MIGRATION_STATUS_POSTCOPY_ACTIVE); 1520 qemu_sem_post(&mis->listen_thread_sem); 1521 trace_postcopy_ram_listen_thread_start(); 1522 1523 /* 1524 * Because we're a thread and not a coroutine we can't yield 1525 * in qemu_file, and thus we must be blocking now. 1526 */ 1527 qemu_file_set_blocking(f, true); 1528 load_res = qemu_loadvm_state_main(f, mis); 1529 /* And non-blocking again so we don't block in any cleanup */ 1530 qemu_file_set_blocking(f, false); 1531 1532 trace_postcopy_ram_listen_thread_exit(); 1533 if (load_res < 0) { 1534 error_report("%s: loadvm failed: %d", __func__, load_res); 1535 qemu_file_set_error(f, load_res); 1536 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1537 MIGRATION_STATUS_FAILED); 1538 } else { 1539 /* 1540 * This looks good, but it's possible that the device loading in the 1541 * main thread hasn't finished yet, and so we might not be in 'RUN' 1542 * state yet; wait for the end of the main thread. 1543 */ 1544 qemu_event_wait(&mis->main_thread_load_event); 1545 } 1546 postcopy_ram_incoming_cleanup(mis); 1547 1548 if (load_res < 0) { 1549 /* 1550 * If something went wrong then we have a bad state so exit; 1551 * depending how far we got it might be possible at this point 1552 * to leave the guest running and fire MCEs for pages that never 1553 * arrived as a desperate recovery step. 1554 */ 1555 exit(EXIT_FAILURE); 1556 } 1557 1558 migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, 1559 MIGRATION_STATUS_COMPLETED); 1560 /* 1561 * If everything has worked fine, then the main thread has waited 1562 * for us to start, and we're the last use of the mis. 1563 * (If something broke then qemu will have to exit anyway since it's 1564 * got a bad migration state). 1565 */ 1566 migration_incoming_state_destroy(); 1567 1568 1569 return NULL; 1570 } 1571 1572 /* After this message we must be able to immediately receive postcopy data */ 1573 static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) 1574 { 1575 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING); 1576 trace_loadvm_postcopy_handle_listen(); 1577 if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) { 1578 error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps); 1579 return -1; 1580 } 1581 if (ps == POSTCOPY_INCOMING_ADVISE) { 1582 /* 1583 * A rare case, we entered listen without having to do any discards, 1584 * so do the setup that's normally done at the time of the 1st discard. 1585 */ 1586 postcopy_ram_prepare_discard(mis); 1587 } 1588 1589 /* 1590 * Sensitise RAM - can now generate requests for blocks that don't exist 1591 * However, at this point the CPU shouldn't be running, and the IO 1592 * shouldn't be doing anything yet so don't actually expect requests 1593 */ 1594 if (postcopy_ram_enable_notify(mis)) { 1595 return -1; 1596 } 1597 1598 if (mis->have_listen_thread) { 1599 error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread"); 1600 return -1; 1601 } 1602 1603 mis->have_listen_thread = true; 1604 /* Start up the listening thread and wait for it to signal ready */ 1605 qemu_sem_init(&mis->listen_thread_sem, 0); 1606 qemu_thread_create(&mis->listen_thread, "postcopy/listen", 1607 postcopy_ram_listen_thread, mis->from_src_file, 1608 QEMU_THREAD_DETACHED); 1609 qemu_sem_wait(&mis->listen_thread_sem); 1610 qemu_sem_destroy(&mis->listen_thread_sem); 1611 1612 return 0; 1613 } 1614 1615 1616 typedef struct { 1617 QEMUBH *bh; 1618 } HandleRunBhData; 1619 1620 static void loadvm_postcopy_handle_run_bh(void *opaque) 1621 { 1622 Error *local_err = NULL; 1623 HandleRunBhData *data = opaque; 1624 1625 /* TODO we should move all of this lot into postcopy_ram.c or a shared code 1626 * in migration.c 1627 */ 1628 cpu_synchronize_all_post_init(); 1629 1630 qemu_announce_self(); 1631 1632 /* Make sure all file formats flush their mutable metadata. 1633 * If we get an error here, just don't restart the VM yet. */ 1634 bdrv_invalidate_cache_all(&local_err); 1635 if (local_err) { 1636 error_report_err(local_err); 1637 local_err = NULL; 1638 autostart = false; 1639 } 1640 1641 trace_loadvm_postcopy_handle_run_cpu_sync(); 1642 cpu_synchronize_all_post_init(); 1643 1644 trace_loadvm_postcopy_handle_run_vmstart(); 1645 1646 if (autostart) { 1647 /* Hold onto your hats, starting the CPU */ 1648 vm_start(); 1649 } else { 1650 /* leave it paused and let management decide when to start the CPU */ 1651 runstate_set(RUN_STATE_PAUSED); 1652 } 1653 1654 qemu_bh_delete(data->bh); 1655 g_free(data); 1656 } 1657 1658 /* After all discards we can start running and asking for pages */ 1659 static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) 1660 { 1661 PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING); 1662 HandleRunBhData *data; 1663 1664 trace_loadvm_postcopy_handle_run(); 1665 if (ps != POSTCOPY_INCOMING_LISTENING) { 1666 error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps); 1667 return -1; 1668 } 1669 1670 data = g_new(HandleRunBhData, 1); 1671 data->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, data); 1672 qemu_bh_schedule(data->bh); 1673 1674 /* We need to finish reading the stream from the package 1675 * and also stop reading anything more from the stream that loaded the 1676 * package (since it's now being read by the listener thread). 1677 * LOADVM_QUIT will quit all the layers of nested loadvm loops. 1678 */ 1679 return LOADVM_QUIT; 1680 } 1681 1682 /** 1683 * Immediately following this command is a blob of data containing an embedded 1684 * chunk of migration stream; read it and load it. 1685 * 1686 * @mis: Incoming state 1687 * @length: Length of packaged data to read 1688 * 1689 * Returns: Negative values on error 1690 * 1691 */ 1692 static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis) 1693 { 1694 int ret; 1695 size_t length; 1696 QIOChannelBuffer *bioc; 1697 1698 length = qemu_get_be32(mis->from_src_file); 1699 trace_loadvm_handle_cmd_packaged(length); 1700 1701 if (length > MAX_VM_CMD_PACKAGED_SIZE) { 1702 error_report("Unreasonably large packaged state: %zu", length); 1703 return -1; 1704 } 1705 1706 bioc = qio_channel_buffer_new(length); 1707 qio_channel_set_name(QIO_CHANNEL(bioc), "migration-loadvm-buffer"); 1708 ret = qemu_get_buffer(mis->from_src_file, 1709 bioc->data, 1710 length); 1711 if (ret != length) { 1712 object_unref(OBJECT(bioc)); 1713 error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu", 1714 ret, length); 1715 return (ret < 0) ? ret : -EAGAIN; 1716 } 1717 bioc->usage += length; 1718 trace_loadvm_handle_cmd_packaged_received(ret); 1719 1720 QEMUFile *packf = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); 1721 1722 ret = qemu_loadvm_state_main(packf, mis); 1723 trace_loadvm_handle_cmd_packaged_main(ret); 1724 qemu_fclose(packf); 1725 object_unref(OBJECT(bioc)); 1726 1727 return ret; 1728 } 1729 1730 /* 1731 * Process an incoming 'QEMU_VM_COMMAND' 1732 * 0 just a normal return 1733 * LOADVM_QUIT All good, but exit the loop 1734 * <0 Error 1735 */ 1736 static int loadvm_process_command(QEMUFile *f) 1737 { 1738 MigrationIncomingState *mis = migration_incoming_get_current(); 1739 uint16_t cmd; 1740 uint16_t len; 1741 uint32_t tmp32; 1742 1743 cmd = qemu_get_be16(f); 1744 len = qemu_get_be16(f); 1745 1746 trace_loadvm_process_command(cmd, len); 1747 if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) { 1748 error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len); 1749 return -EINVAL; 1750 } 1751 1752 if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) { 1753 error_report("%s received with bad length - expecting %zu, got %d", 1754 mig_cmd_args[cmd].name, 1755 (size_t)mig_cmd_args[cmd].len, len); 1756 return -ERANGE; 1757 } 1758 1759 switch (cmd) { 1760 case MIG_CMD_OPEN_RETURN_PATH: 1761 if (mis->to_src_file) { 1762 error_report("CMD_OPEN_RETURN_PATH called when RP already open"); 1763 /* Not really a problem, so don't give up */ 1764 return 0; 1765 } 1766 mis->to_src_file = qemu_file_get_return_path(f); 1767 if (!mis->to_src_file) { 1768 error_report("CMD_OPEN_RETURN_PATH failed"); 1769 return -1; 1770 } 1771 break; 1772 1773 case MIG_CMD_PING: 1774 tmp32 = qemu_get_be32(f); 1775 trace_loadvm_process_command_ping(tmp32); 1776 if (!mis->to_src_file) { 1777 error_report("CMD_PING (0x%x) received with no return path", 1778 tmp32); 1779 return -1; 1780 } 1781 migrate_send_rp_pong(mis, tmp32); 1782 break; 1783 1784 case MIG_CMD_PACKAGED: 1785 return loadvm_handle_cmd_packaged(mis); 1786 1787 case MIG_CMD_POSTCOPY_ADVISE: 1788 return loadvm_postcopy_handle_advise(mis); 1789 1790 case MIG_CMD_POSTCOPY_LISTEN: 1791 return loadvm_postcopy_handle_listen(mis); 1792 1793 case MIG_CMD_POSTCOPY_RUN: 1794 return loadvm_postcopy_handle_run(mis); 1795 1796 case MIG_CMD_POSTCOPY_RAM_DISCARD: 1797 return loadvm_postcopy_ram_handle_discard(mis, len); 1798 } 1799 1800 return 0; 1801 } 1802 1803 struct LoadStateEntry { 1804 QLIST_ENTRY(LoadStateEntry) entry; 1805 SaveStateEntry *se; 1806 int section_id; 1807 int version_id; 1808 }; 1809 1810 /* 1811 * Read a footer off the wire and check that it matches the expected section 1812 * 1813 * Returns: true if the footer was good 1814 * false if there is a problem (and calls error_report to say why) 1815 */ 1816 static bool check_section_footer(QEMUFile *f, LoadStateEntry *le) 1817 { 1818 uint8_t read_mark; 1819 uint32_t read_section_id; 1820 1821 if (skip_section_footers) { 1822 /* No footer to check */ 1823 return true; 1824 } 1825 1826 read_mark = qemu_get_byte(f); 1827 1828 if (read_mark != QEMU_VM_SECTION_FOOTER) { 1829 error_report("Missing section footer for %s", le->se->idstr); 1830 return false; 1831 } 1832 1833 read_section_id = qemu_get_be32(f); 1834 if (read_section_id != le->section_id) { 1835 error_report("Mismatched section id in footer for %s -" 1836 " read 0x%x expected 0x%x", 1837 le->se->idstr, read_section_id, le->section_id); 1838 return false; 1839 } 1840 1841 /* All good */ 1842 return true; 1843 } 1844 1845 void loadvm_free_handlers(MigrationIncomingState *mis) 1846 { 1847 LoadStateEntry *le, *new_le; 1848 1849 QLIST_FOREACH_SAFE(le, &mis->loadvm_handlers, entry, new_le) { 1850 QLIST_REMOVE(le, entry); 1851 g_free(le); 1852 } 1853 } 1854 1855 static int 1856 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis) 1857 { 1858 uint32_t instance_id, version_id, section_id; 1859 SaveStateEntry *se; 1860 LoadStateEntry *le; 1861 char idstr[256]; 1862 int ret; 1863 1864 /* Read section start */ 1865 section_id = qemu_get_be32(f); 1866 if (!qemu_get_counted_string(f, idstr)) { 1867 error_report("Unable to read ID string for section %u", 1868 section_id); 1869 return -EINVAL; 1870 } 1871 instance_id = qemu_get_be32(f); 1872 version_id = qemu_get_be32(f); 1873 1874 trace_qemu_loadvm_state_section_startfull(section_id, idstr, 1875 instance_id, version_id); 1876 /* Find savevm section */ 1877 se = find_se(idstr, instance_id); 1878 if (se == NULL) { 1879 error_report("Unknown savevm section or instance '%s' %d", 1880 idstr, instance_id); 1881 return -EINVAL; 1882 } 1883 1884 /* Validate version */ 1885 if (version_id > se->version_id) { 1886 error_report("savevm: unsupported version %d for '%s' v%d", 1887 version_id, idstr, se->version_id); 1888 return -EINVAL; 1889 } 1890 1891 /* Validate if it is a device's state */ 1892 if (xen_enabled() && se->is_ram) { 1893 error_report("loadvm: %s RAM loading not allowed on Xen", idstr); 1894 return -EINVAL; 1895 } 1896 1897 /* Add entry */ 1898 le = g_malloc0(sizeof(*le)); 1899 1900 le->se = se; 1901 le->section_id = section_id; 1902 le->version_id = version_id; 1903 QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry); 1904 1905 ret = vmstate_load(f, le->se, le->version_id); 1906 if (ret < 0) { 1907 error_report("error while loading state for instance 0x%x of" 1908 " device '%s'", instance_id, idstr); 1909 return ret; 1910 } 1911 if (!check_section_footer(f, le)) { 1912 return -EINVAL; 1913 } 1914 1915 return 0; 1916 } 1917 1918 static int 1919 qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis) 1920 { 1921 uint32_t section_id; 1922 LoadStateEntry *le; 1923 int ret; 1924 1925 section_id = qemu_get_be32(f); 1926 1927 trace_qemu_loadvm_state_section_partend(section_id); 1928 QLIST_FOREACH(le, &mis->loadvm_handlers, entry) { 1929 if (le->section_id == section_id) { 1930 break; 1931 } 1932 } 1933 if (le == NULL) { 1934 error_report("Unknown savevm section %d", section_id); 1935 return -EINVAL; 1936 } 1937 1938 ret = vmstate_load(f, le->se, le->version_id); 1939 if (ret < 0) { 1940 error_report("error while loading state section id %d(%s)", 1941 section_id, le->se->idstr); 1942 return ret; 1943 } 1944 if (!check_section_footer(f, le)) { 1945 return -EINVAL; 1946 } 1947 1948 return 0; 1949 } 1950 1951 static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis) 1952 { 1953 uint8_t section_type; 1954 int ret = 0; 1955 1956 while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) { 1957 ret = 0; 1958 trace_qemu_loadvm_state_section(section_type); 1959 switch (section_type) { 1960 case QEMU_VM_SECTION_START: 1961 case QEMU_VM_SECTION_FULL: 1962 ret = qemu_loadvm_section_start_full(f, mis); 1963 if (ret < 0) { 1964 goto out; 1965 } 1966 break; 1967 case QEMU_VM_SECTION_PART: 1968 case QEMU_VM_SECTION_END: 1969 ret = qemu_loadvm_section_part_end(f, mis); 1970 if (ret < 0) { 1971 goto out; 1972 } 1973 break; 1974 case QEMU_VM_COMMAND: 1975 ret = loadvm_process_command(f); 1976 trace_qemu_loadvm_state_section_command(ret); 1977 if ((ret < 0) || (ret & LOADVM_QUIT)) { 1978 goto out; 1979 } 1980 break; 1981 default: 1982 error_report("Unknown savevm section type %d", section_type); 1983 ret = -EINVAL; 1984 goto out; 1985 } 1986 } 1987 1988 out: 1989 if (ret < 0) { 1990 qemu_file_set_error(f, ret); 1991 } 1992 return ret; 1993 } 1994 1995 int qemu_loadvm_state(QEMUFile *f) 1996 { 1997 MigrationIncomingState *mis = migration_incoming_get_current(); 1998 Error *local_err = NULL; 1999 unsigned int v; 2000 int ret; 2001 2002 if (qemu_savevm_state_blocked(&local_err)) { 2003 error_report_err(local_err); 2004 return -EINVAL; 2005 } 2006 2007 v = qemu_get_be32(f); 2008 if (v != QEMU_VM_FILE_MAGIC) { 2009 error_report("Not a migration stream"); 2010 return -EINVAL; 2011 } 2012 2013 v = qemu_get_be32(f); 2014 if (v == QEMU_VM_FILE_VERSION_COMPAT) { 2015 error_report("SaveVM v2 format is obsolete and don't work anymore"); 2016 return -ENOTSUP; 2017 } 2018 if (v != QEMU_VM_FILE_VERSION) { 2019 error_report("Unsupported migration stream version"); 2020 return -ENOTSUP; 2021 } 2022 2023 if (!savevm_state.skip_configuration || enforce_config_section()) { 2024 if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) { 2025 error_report("Configuration section missing"); 2026 return -EINVAL; 2027 } 2028 ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0); 2029 2030 if (ret) { 2031 return ret; 2032 } 2033 } 2034 2035 ret = qemu_loadvm_state_main(f, mis); 2036 qemu_event_set(&mis->main_thread_load_event); 2037 2038 trace_qemu_loadvm_state_post_main(ret); 2039 2040 if (mis->have_listen_thread) { 2041 /* Listen thread still going, can't clean up yet */ 2042 return ret; 2043 } 2044 2045 if (ret == 0) { 2046 ret = qemu_file_get_error(f); 2047 } 2048 2049 /* 2050 * Try to read in the VMDESC section as well, so that dumping tools that 2051 * intercept our migration stream have the chance to see it. 2052 */ 2053 2054 /* We've got to be careful; if we don't read the data and just shut the fd 2055 * then the sender can error if we close while it's still sending. 2056 * We also mustn't read data that isn't there; some transports (RDMA) 2057 * will stall waiting for that data when the source has already closed. 2058 */ 2059 if (ret == 0 && should_send_vmdesc()) { 2060 uint8_t *buf; 2061 uint32_t size; 2062 uint8_t section_type = qemu_get_byte(f); 2063 2064 if (section_type != QEMU_VM_VMDESCRIPTION) { 2065 error_report("Expected vmdescription section, but got %d", 2066 section_type); 2067 /* 2068 * It doesn't seem worth failing at this point since 2069 * we apparently have an otherwise valid VM state 2070 */ 2071 } else { 2072 buf = g_malloc(0x1000); 2073 size = qemu_get_be32(f); 2074 2075 while (size > 0) { 2076 uint32_t read_chunk = MIN(size, 0x1000); 2077 qemu_get_buffer(f, buf, read_chunk); 2078 size -= read_chunk; 2079 } 2080 g_free(buf); 2081 } 2082 } 2083 2084 cpu_synchronize_all_post_init(); 2085 2086 return ret; 2087 } 2088 2089 int save_vmstate(const char *name, Error **errp) 2090 { 2091 BlockDriverState *bs, *bs1; 2092 QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1; 2093 int ret = -1; 2094 QEMUFile *f; 2095 int saved_vm_running; 2096 uint64_t vm_state_size; 2097 qemu_timeval tv; 2098 struct tm tm; 2099 AioContext *aio_context; 2100 2101 if (!bdrv_all_can_snapshot(&bs)) { 2102 error_setg(errp, "Device '%s' is writable but does not support " 2103 "snapshots", bdrv_get_device_name(bs)); 2104 return ret; 2105 } 2106 2107 /* Delete old snapshots of the same name */ 2108 if (name) { 2109 ret = bdrv_all_delete_snapshot(name, &bs1, errp); 2110 if (ret < 0) { 2111 error_prepend(errp, "Error while deleting snapshot on device " 2112 "'%s': ", bdrv_get_device_name(bs1)); 2113 return ret; 2114 } 2115 } 2116 2117 bs = bdrv_all_find_vmstate_bs(); 2118 if (bs == NULL) { 2119 error_setg(errp, "No block device can accept snapshots"); 2120 return ret; 2121 } 2122 aio_context = bdrv_get_aio_context(bs); 2123 2124 saved_vm_running = runstate_is_running(); 2125 2126 ret = global_state_store(); 2127 if (ret) { 2128 error_setg(errp, "Error saving global state"); 2129 return ret; 2130 } 2131 vm_stop(RUN_STATE_SAVE_VM); 2132 2133 aio_context_acquire(aio_context); 2134 2135 memset(sn, 0, sizeof(*sn)); 2136 2137 /* fill auxiliary fields */ 2138 qemu_gettimeofday(&tv); 2139 sn->date_sec = tv.tv_sec; 2140 sn->date_nsec = tv.tv_usec * 1000; 2141 sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 2142 2143 if (name) { 2144 ret = bdrv_snapshot_find(bs, old_sn, name); 2145 if (ret >= 0) { 2146 pstrcpy(sn->name, sizeof(sn->name), old_sn->name); 2147 pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str); 2148 } else { 2149 pstrcpy(sn->name, sizeof(sn->name), name); 2150 } 2151 } else { 2152 /* cast below needed for OpenBSD where tv_sec is still 'long' */ 2153 localtime_r((const time_t *)&tv.tv_sec, &tm); 2154 strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm); 2155 } 2156 2157 /* save the VM state */ 2158 f = qemu_fopen_bdrv(bs, 1); 2159 if (!f) { 2160 error_setg(errp, "Could not open VM state file"); 2161 goto the_end; 2162 } 2163 ret = qemu_savevm_state(f, errp); 2164 vm_state_size = qemu_ftell(f); 2165 qemu_fclose(f); 2166 if (ret < 0) { 2167 goto the_end; 2168 } 2169 2170 ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs); 2171 if (ret < 0) { 2172 error_setg(errp, "Error while creating snapshot on '%s'", 2173 bdrv_get_device_name(bs)); 2174 goto the_end; 2175 } 2176 2177 ret = 0; 2178 2179 the_end: 2180 aio_context_release(aio_context); 2181 if (saved_vm_running) { 2182 vm_start(); 2183 } 2184 return ret; 2185 } 2186 2187 void qmp_xen_save_devices_state(const char *filename, Error **errp) 2188 { 2189 QEMUFile *f; 2190 QIOChannelFile *ioc; 2191 int saved_vm_running; 2192 int ret; 2193 2194 saved_vm_running = runstate_is_running(); 2195 vm_stop(RUN_STATE_SAVE_VM); 2196 global_state_store_running(); 2197 2198 ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT, 0660, errp); 2199 if (!ioc) { 2200 goto the_end; 2201 } 2202 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-save-state"); 2203 f = qemu_fopen_channel_output(QIO_CHANNEL(ioc)); 2204 ret = qemu_save_device_state(f); 2205 qemu_fclose(f); 2206 if (ret < 0) { 2207 error_setg(errp, QERR_IO_ERROR); 2208 } 2209 2210 the_end: 2211 if (saved_vm_running) { 2212 vm_start(); 2213 } 2214 } 2215 2216 void qmp_xen_load_devices_state(const char *filename, Error **errp) 2217 { 2218 QEMUFile *f; 2219 QIOChannelFile *ioc; 2220 int ret; 2221 2222 /* Guest must be paused before loading the device state; the RAM state 2223 * will already have been loaded by xc 2224 */ 2225 if (runstate_is_running()) { 2226 error_setg(errp, "Cannot update device state while vm is running"); 2227 return; 2228 } 2229 vm_stop(RUN_STATE_RESTORE_VM); 2230 2231 ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0, errp); 2232 if (!ioc) { 2233 return; 2234 } 2235 qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-load-state"); 2236 f = qemu_fopen_channel_input(QIO_CHANNEL(ioc)); 2237 2238 ret = qemu_loadvm_state(f); 2239 qemu_fclose(f); 2240 if (ret < 0) { 2241 error_setg(errp, QERR_IO_ERROR); 2242 } 2243 migration_incoming_state_destroy(); 2244 } 2245 2246 int load_vmstate(const char *name, Error **errp) 2247 { 2248 BlockDriverState *bs, *bs_vm_state; 2249 QEMUSnapshotInfo sn; 2250 QEMUFile *f; 2251 int ret; 2252 AioContext *aio_context; 2253 MigrationIncomingState *mis = migration_incoming_get_current(); 2254 2255 if (!bdrv_all_can_snapshot(&bs)) { 2256 error_setg(errp, 2257 "Device '%s' is writable but does not support snapshots", 2258 bdrv_get_device_name(bs)); 2259 return -ENOTSUP; 2260 } 2261 ret = bdrv_all_find_snapshot(name, &bs); 2262 if (ret < 0) { 2263 error_setg(errp, 2264 "Device '%s' does not have the requested snapshot '%s'", 2265 bdrv_get_device_name(bs), name); 2266 return ret; 2267 } 2268 2269 bs_vm_state = bdrv_all_find_vmstate_bs(); 2270 if (!bs_vm_state) { 2271 error_setg(errp, "No block device supports snapshots"); 2272 return -ENOTSUP; 2273 } 2274 aio_context = bdrv_get_aio_context(bs_vm_state); 2275 2276 /* Don't even try to load empty VM states */ 2277 aio_context_acquire(aio_context); 2278 ret = bdrv_snapshot_find(bs_vm_state, &sn, name); 2279 aio_context_release(aio_context); 2280 if (ret < 0) { 2281 return ret; 2282 } else if (sn.vm_state_size == 0) { 2283 error_setg(errp, "This is a disk-only snapshot. Revert to it " 2284 " offline using qemu-img"); 2285 return -EINVAL; 2286 } 2287 2288 /* Flush all IO requests so they don't interfere with the new state. */ 2289 bdrv_drain_all(); 2290 2291 ret = bdrv_all_goto_snapshot(name, &bs); 2292 if (ret < 0) { 2293 error_setg(errp, "Error %d while activating snapshot '%s' on '%s'", 2294 ret, name, bdrv_get_device_name(bs)); 2295 return ret; 2296 } 2297 2298 /* restore the VM state */ 2299 f = qemu_fopen_bdrv(bs_vm_state, 0); 2300 if (!f) { 2301 error_setg(errp, "Could not open VM state file"); 2302 return -EINVAL; 2303 } 2304 2305 qemu_system_reset(SHUTDOWN_CAUSE_NONE); 2306 mis->from_src_file = f; 2307 2308 aio_context_acquire(aio_context); 2309 ret = qemu_loadvm_state(f); 2310 qemu_fclose(f); 2311 aio_context_release(aio_context); 2312 2313 migration_incoming_state_destroy(); 2314 if (ret < 0) { 2315 error_setg(errp, "Error %d while loading VM state", ret); 2316 return ret; 2317 } 2318 2319 return 0; 2320 } 2321 2322 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev) 2323 { 2324 qemu_ram_set_idstr(mr->ram_block, 2325 memory_region_name(mr), dev); 2326 } 2327 2328 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev) 2329 { 2330 qemu_ram_unset_idstr(mr->ram_block); 2331 } 2332 2333 void vmstate_register_ram_global(MemoryRegion *mr) 2334 { 2335 vmstate_register_ram(mr, NULL); 2336 } 2337 2338 bool vmstate_check_only_migratable(const VMStateDescription *vmsd) 2339 { 2340 /* check needed if --only-migratable is specified */ 2341 if (!only_migratable) { 2342 return true; 2343 } 2344 2345 return !(vmsd && vmsd->unmigratable); 2346 } 2347