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