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