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