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