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