savevm.c

   1 /*
   2  * QEMU System Emulator
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "config-host.h"
  26 #include "qemu-common.h"
  27 #include "hw/boards.h"
  28 #include "hw/hw.h"
  29 #include "hw/qdev.h"
  30 #include "net/net.h"
  31 #include "monitor/monitor.h"
  32 #include "sysemu/sysemu.h"
  33 #include "qemu/timer.h"
  34 #include "audio/audio.h"
  35 #include "migration/migration.h"
  36 #include "qemu/sockets.h"
  37 #include "qemu/queue.h"
  38 #include "sysemu/cpus.h"
  39 #include "exec/memory.h"
  40 #include "qmp-commands.h"
  41 #include "trace.h"
  42 #include "qemu/iov.h"
  43 #include "block/snapshot.h"
  44 #include "block/qapi.h"
  45
  46
  47 #ifndef ETH_P_RARP
  48 #define ETH_P_RARP 0x8035
  49 #endif
  50 #define ARP_HTYPE_ETH 0x0001
  51 #define ARP_PTYPE_IP 0x0800
  52 #define ARP_OP_REQUEST_REV 0x3
  53
  54 static int announce_self_create(uint8_t *buf,
  55                                 uint8_t *mac_addr)
  56 {
  57     /* Ethernet header. */
  58     memset(buf, 0xff, 6);         /* destination MAC addr */
  59     memcpy(buf + 6, mac_addr, 6); /* source MAC addr */
  60     *(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */
  61
  62     /* RARP header. */
  63     *(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */
  64     *(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */
  65     *(buf + 18) = 6; /* hardware addr length (ethernet) */
  66     *(buf + 19) = 4; /* protocol addr length (IPv4) */
  67     *(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */
  68     memcpy(buf + 22, mac_addr, 6); /* source hw addr */
  69     memset(buf + 28, 0x00, 4);     /* source protocol addr */
  70     memcpy(buf + 32, mac_addr, 6); /* target hw addr */
  71     memset(buf + 38, 0x00, 4);     /* target protocol addr */
  72
  73     /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
  74     memset(buf + 42, 0x00, 18);
  75
  76     return 60; /* len (FCS will be added by hardware) */
  77 }
  78
  79 static void qemu_announce_self_iter(NICState *nic, void *opaque)
  80 {
  81     uint8_t buf[60];
  82     int len;
  83
  84     trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr));
  85     len = announce_self_create(buf, nic->conf->macaddr.a);
  86
  87     qemu_send_packet_raw(qemu_get_queue(nic), buf, len);
  88 }
  89
  90
  91 static void qemu_announce_self_once(void *opaque)
  92 {
  93     static int count = SELF_ANNOUNCE_ROUNDS;
  94     QEMUTimer *timer = *(QEMUTimer **)opaque;
  95
  96     qemu_foreach_nic(qemu_announce_self_iter, NULL);
  97
  98     if (--count) {
  99         /* delay 50ms, 150ms, 250ms, ... */
 100         timer_mod(timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) +
 101                   self_announce_delay(count));
 102     } else {
 103             timer_del(timer);
 104             timer_free(timer);
 105     }
 106 }
 107
 108 void qemu_announce_self(void)
 109 {
 110     static QEMUTimer *timer;
 111     timer = timer_new_ms(QEMU_CLOCK_REALTIME, qemu_announce_self_once, &timer);
 112     qemu_announce_self_once(&timer);
 113 }
 114
 115 /***********************************************************/
 116 /* savevm/loadvm support */
 117
 118 static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
 119                                    int64_t pos)
 120 {
 121     int ret;
 122     QEMUIOVector qiov;
 123
 124     qemu_iovec_init_external(&qiov, iov, iovcnt);
 125     ret = bdrv_writev_vmstate(opaque, &qiov, pos);
 126     if (ret < 0) {
 127         return ret;
 128     }
 129
 130     return qiov.size;
 131 }
 132
 133 static int block_put_buffer(void *opaque, const uint8_t *buf,
 134                            int64_t pos, int size)
 135 {
 136     bdrv_save_vmstate(opaque, buf, pos, size);
 137     return size;
 138 }
 139
 140 static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
 141 {
 142     return bdrv_load_vmstate(opaque, buf, pos, size);
 143 }
 144
 145 static int bdrv_fclose(void *opaque)
 146 {
 147     return bdrv_flush(opaque);
 148 }
 149
 150 static const QEMUFileOps bdrv_read_ops = {
 151     .get_buffer = block_get_buffer,
 152     .close =      bdrv_fclose
 153 };
 154
 155 static const QEMUFileOps bdrv_write_ops = {
 156     .put_buffer     = block_put_buffer,
 157     .writev_buffer  = block_writev_buffer,
 158     .close          = bdrv_fclose
 159 };
 160
 161 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
 162 {
 163     if (is_writable) {
 164         return qemu_fopen_ops(bs, &bdrv_write_ops);
 165     }
 166     return qemu_fopen_ops(bs, &bdrv_read_ops);
 167 }
 168
 169
 170 /* QEMUFile timer support.
 171  * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
 172  */
 173
 174 void timer_put(QEMUFile *f, QEMUTimer *ts)
 175 {
 176     uint64_t expire_time;
 177
 178     expire_time = timer_expire_time_ns(ts);
 179     qemu_put_be64(f, expire_time);
 180 }
 181
 182 void timer_get(QEMUFile *f, QEMUTimer *ts)
 183 {
 184     uint64_t expire_time;
 185
 186     expire_time = qemu_get_be64(f);
 187     if (expire_time != -1) {
 188         timer_mod_ns(ts, expire_time);
 189     } else {
 190         timer_del(ts);
 191     }
 192 }
 193
 194
 195 /* VMState timer support.
 196  * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
 197  */
 198
 199 static int get_timer(QEMUFile *f, void *pv, size_t size)
 200 {
 201     QEMUTimer *v = pv;
 202     timer_get(f, v);
 203     return 0;
 204 }
 205
 206 static void put_timer(QEMUFile *f, void *pv, size_t size)
 207 {
 208     QEMUTimer *v = pv;
 209     timer_put(f, v);
 210 }
 211
 212 const VMStateInfo vmstate_info_timer = {
 213     .name = "timer",
 214     .get  = get_timer,
 215     .put  = put_timer,
 216 };
 217
 218
 219 typedef struct CompatEntry {
 220     char idstr[256];
 221     int instance_id;
 222 } CompatEntry;
 223
 224 typedef struct SaveStateEntry {
 225     QTAILQ_ENTRY(SaveStateEntry) entry;
 226     char idstr[256];
 227     int instance_id;
 228     int alias_id;
 229     int version_id;
 230     int section_id;
 231     SaveVMHandlers *ops;
 232     const VMStateDescription *vmsd;
 233     void *opaque;
 234     CompatEntry *compat;
 235     int is_ram;
 236 } SaveStateEntry;
 237
 238
 239 static QTAILQ_HEAD(savevm_handlers, SaveStateEntry) savevm_handlers =
 240     QTAILQ_HEAD_INITIALIZER(savevm_handlers);
 241 static int global_section_id;
 242
 243 static void dump_vmstate_vmsd(FILE *out_file,
 244                               const VMStateDescription *vmsd, int indent,
 245                               bool is_subsection);
 246
 247 static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
 248                               int indent)
 249 {
 250     fprintf(out_file, "%*s{\n", indent, "");
 251     indent += 2;
 252     fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name);
 253     fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
 254             field->version_id);
 255     fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "",
 256             field->field_exists ? "true" : "false");
 257     fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size);
 258     if (field->vmsd != NULL) {
 259         fprintf(out_file, ",\n");
 260         dump_vmstate_vmsd(out_file, field->vmsd, indent, false);
 261     }
 262     fprintf(out_file, "\n%*s}", indent - 2, "");
 263 }
 264
 265 static void dump_vmstate_vmss(FILE *out_file,
 266                               const VMStateSubsection *subsection,
 267                               int indent)
 268 {
 269     if (subsection->vmsd != NULL) {
 270         dump_vmstate_vmsd(out_file, subsection->vmsd, indent, true);
 271     }
 272 }
 273
 274 static void dump_vmstate_vmsd(FILE *out_file,
 275                               const VMStateDescription *vmsd, int indent,
 276                               bool is_subsection)
 277 {
 278     if (is_subsection) {
 279         fprintf(out_file, "%*s{\n", indent, "");
 280     } else {
 281         fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description");
 282     }
 283     indent += 2;
 284     fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name);
 285     fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
 286             vmsd->version_id);
 287     fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "",
 288             vmsd->minimum_version_id);
 289     if (vmsd->fields != NULL) {
 290         const VMStateField *field = vmsd->fields;
 291         bool first;
 292
 293         fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, "");
 294         first = true;
 295         while (field->name != NULL) {
 296             if (field->flags & VMS_MUST_EXIST) {
 297                 /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
 298                 field++;
 299                 continue;
 300             }
 301             if (!first) {
 302                 fprintf(out_file, ",\n");
 303             }
 304             dump_vmstate_vmsf(out_file, field, indent + 2);
 305             field++;
 306             first = false;
 307         }
 308         fprintf(out_file, "\n%*s]", indent, "");
 309     }
 310     if (vmsd->subsections != NULL) {
 311         const VMStateSubsection *subsection = vmsd->subsections;
 312         bool first;
 313
 314         fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
 315         first = true;
 316         while (subsection->vmsd != NULL) {
 317             if (!first) {
 318                 fprintf(out_file, ",\n");
 319             }
 320             dump_vmstate_vmss(out_file, subsection, indent + 2);
 321             subsection++;
 322             first = false;
 323         }
 324         fprintf(out_file, "\n%*s]", indent, "");
 325     }
 326     fprintf(out_file, "\n%*s}", indent - 2, "");
 327 }
 328
 329 static void dump_machine_type(FILE *out_file)
 330 {
 331     MachineClass *mc;
 332
 333     mc = MACHINE_GET_CLASS(current_machine);
 334
 335     fprintf(out_file, "  \"vmschkmachine\": {\n");
 336     fprintf(out_file, "    \"Name\": \"%s\"\n", mc->name);
 337     fprintf(out_file, "  },\n");
 338 }
 339
 340 void dump_vmstate_json_to_file(FILE *out_file)
 341 {
 342     GSList *list, *elt;
 343     bool first;
 344
 345     fprintf(out_file, "{\n");
 346     dump_machine_type(out_file);
 347
 348     first = true;
 349     list = object_class_get_list(TYPE_DEVICE, true);
 350     for (elt = list; elt; elt = elt->next) {
 351         DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data,
 352                                              TYPE_DEVICE);
 353         const char *name;
 354         int indent = 2;
 355
 356         if (!dc->vmsd) {
 357             continue;
 358         }
 359
 360         if (!first) {
 361             fprintf(out_file, ",\n");
 362         }
 363         name = object_class_get_name(OBJECT_CLASS(dc));
 364         fprintf(out_file, "%*s\"%s\": {\n", indent, "", name);
 365         indent += 2;
 366         fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name);
 367         fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
 368                 dc->vmsd->version_id);
 369         fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "",
 370                 dc->vmsd->minimum_version_id);
 371
 372         dump_vmstate_vmsd(out_file, dc->vmsd, indent, false);
 373
 374         fprintf(out_file, "\n%*s}", indent - 2, "");
 375         first = false;
 376     }
 377     fprintf(out_file, "\n}\n");
 378     fclose(out_file);
 379 }
 380
 381 static int calculate_new_instance_id(const char *idstr)
 382 {
 383     SaveStateEntry *se;
 384     int instance_id = 0;
 385
 386     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 387         if (strcmp(idstr, se->idstr) == 0
 388             && instance_id <= se->instance_id) {
 389             instance_id = se->instance_id + 1;
 390         }
 391     }
 392     return instance_id;
 393 }
 394
 395 static int calculate_compat_instance_id(const char *idstr)
 396 {
 397     SaveStateEntry *se;
 398     int instance_id = 0;
 399
 400     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 401         if (!se->compat) {
 402             continue;
 403         }
 404
 405         if (strcmp(idstr, se->compat->idstr) == 0
 406             && instance_id <= se->compat->instance_id) {
 407             instance_id = se->compat->instance_id + 1;
 408         }
 409     }
 410     return instance_id;
 411 }
 412
 413 /* TODO: Individual devices generally have very little idea about the rest
 414    of the system, so instance_id should be removed/replaced.
 415    Meanwhile pass -1 as instance_id if you do not already have a clearly
 416    distinguishing id for all instances of your device class. */
 417 int register_savevm_live(DeviceState *dev,
 418                          const char *idstr,
 419                          int instance_id,
 420                          int version_id,
 421                          SaveVMHandlers *ops,
 422                          void *opaque)
 423 {
 424     SaveStateEntry *se;
 425
 426     se = g_malloc0(sizeof(SaveStateEntry));
 427     se->version_id = version_id;
 428     se->section_id = global_section_id++;
 429     se->ops = ops;
 430     se->opaque = opaque;
 431     se->vmsd = NULL;
 432     /* if this is a live_savem then set is_ram */
 433     if (ops->save_live_setup != NULL) {
 434         se->is_ram = 1;
 435     }
 436
 437     if (dev) {
 438         char *id = qdev_get_dev_path(dev);
 439         if (id) {
 440             pstrcpy(se->idstr, sizeof(se->idstr), id);
 441             pstrcat(se->idstr, sizeof(se->idstr), "/");
 442             g_free(id);
 443
 444             se->compat = g_malloc0(sizeof(CompatEntry));
 445             pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr);
 446             se->compat->instance_id = instance_id == -1 ?
 447                          calculate_compat_instance_id(idstr) : instance_id;
 448             instance_id = -1;
 449         }
 450     }
 451     pstrcat(se->idstr, sizeof(se->idstr), idstr);
 452
 453     if (instance_id == -1) {
 454         se->instance_id = calculate_new_instance_id(se->idstr);
 455     } else {
 456         se->instance_id = instance_id;
 457     }
 458     assert(!se->compat || se->instance_id == 0);
 459     /* add at the end of list */
 460     QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
 461     return 0;
 462 }
 463
 464 int register_savevm(DeviceState *dev,
 465                     const char *idstr,
 466                     int instance_id,
 467                     int version_id,
 468                     SaveStateHandler *save_state,
 469                     LoadStateHandler *load_state,
 470                     void *opaque)
 471 {
 472     SaveVMHandlers *ops = g_malloc0(sizeof(SaveVMHandlers));
 473     ops->save_state = save_state;
 474     ops->load_state = load_state;
 475     return register_savevm_live(dev, idstr, instance_id, version_id,
 476                                 ops, opaque);
 477 }
 478
 479 void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque)
 480 {
 481     SaveStateEntry *se, *new_se;
 482     char id[256] = "";
 483
 484     if (dev) {
 485         char *path = qdev_get_dev_path(dev);
 486         if (path) {
 487             pstrcpy(id, sizeof(id), path);
 488             pstrcat(id, sizeof(id), "/");
 489             g_free(path);
 490         }
 491     }
 492     pstrcat(id, sizeof(id), idstr);
 493
 494     QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
 495         if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
 496             QTAILQ_REMOVE(&savevm_handlers, se, entry);
 497             if (se->compat) {
 498                 g_free(se->compat);
 499             }
 500             g_free(se->ops);
 501             g_free(se);
 502         }
 503     }
 504 }
 505
 506 int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
 507                                    const VMStateDescription *vmsd,
 508                                    void *opaque, int alias_id,
 509                                    int required_for_version)
 510 {
 511     SaveStateEntry *se;
 512
 513     /* If this triggers, alias support can be dropped for the vmsd. */
 514     assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id);
 515
 516     se = g_malloc0(sizeof(SaveStateEntry));
 517     se->version_id = vmsd->version_id;
 518     se->section_id = global_section_id++;
 519     se->opaque = opaque;
 520     se->vmsd = vmsd;
 521     se->alias_id = alias_id;
 522
 523     if (dev) {
 524         char *id = qdev_get_dev_path(dev);
 525         if (id) {
 526             pstrcpy(se->idstr, sizeof(se->idstr), id);
 527             pstrcat(se->idstr, sizeof(se->idstr), "/");
 528             g_free(id);
 529
 530             se->compat = g_malloc0(sizeof(CompatEntry));
 531             pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
 532             se->compat->instance_id = instance_id == -1 ?
 533                          calculate_compat_instance_id(vmsd->name) : instance_id;
 534             instance_id = -1;
 535         }
 536     }
 537     pstrcat(se->idstr, sizeof(se->idstr), vmsd->name);
 538
 539     if (instance_id == -1) {
 540         se->instance_id = calculate_new_instance_id(se->idstr);
 541     } else {
 542         se->instance_id = instance_id;
 543     }
 544     assert(!se->compat || se->instance_id == 0);
 545     /* add at the end of list */
 546     QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
 547     return 0;
 548 }
 549
 550 void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd,
 551                         void *opaque)
 552 {
 553     SaveStateEntry *se, *new_se;
 554
 555     QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
 556         if (se->vmsd == vmsd && se->opaque == opaque) {
 557             QTAILQ_REMOVE(&savevm_handlers, se, entry);
 558             if (se->compat) {
 559                 g_free(se->compat);
 560             }
 561             g_free(se);
 562         }
 563     }
 564 }
 565
 566 static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id)
 567 {
 568     trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
 569     if (!se->vmsd) {         /* Old style */
 570         return se->ops->load_state(f, se->opaque, version_id);
 571     }
 572     return vmstate_load_state(f, se->vmsd, se->opaque, version_id);
 573 }
 574
 575 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
 576 {
 577     int64_t old_offset, size;
 578
 579     old_offset = qemu_ftell_fast(f);
 580     se->ops->save_state(f, se->opaque);
 581     size = qemu_ftell_fast(f) - old_offset;
 582
 583     if (vmdesc) {
 584         json_prop_int(vmdesc, "size", size);
 585         json_start_array(vmdesc, "fields");
 586         json_start_object(vmdesc, NULL);
 587         json_prop_str(vmdesc, "name", "data");
 588         json_prop_int(vmdesc, "size", size);
 589         json_prop_str(vmdesc, "type", "buffer");
 590         json_end_object(vmdesc);
 591         json_end_array(vmdesc);
 592     }
 593 }
 594
 595 static void vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
 596 {
 597     trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
 598     if (!se->vmsd) {
 599         vmstate_save_old_style(f, se, vmdesc);
 600         return;
 601     }
 602     vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
 603 }
 604
 605 bool qemu_savevm_state_blocked(Error **errp)
 606 {
 607     SaveStateEntry *se;
 608
 609     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 610         if (se->vmsd && se->vmsd->unmigratable) {
 611             error_setg(errp, "State blocked by non-migratable device '%s'",
 612                        se->idstr);
 613             return true;
 614         }
 615     }
 616     return false;
 617 }
 618
 619 void qemu_savevm_state_begin(QEMUFile *f,
 620                              const MigrationParams *params)
 621 {
 622     SaveStateEntry *se;
 623     int ret;
 624
 625     trace_savevm_state_begin();
 626     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 627         if (!se->ops || !se->ops->set_params) {
 628             continue;
 629         }
 630         se->ops->set_params(params, se->opaque);
 631     }
 632
 633     qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
 634     qemu_put_be32(f, QEMU_VM_FILE_VERSION);
 635
 636     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 637         int len;
 638
 639         if (!se->ops || !se->ops->save_live_setup) {
 640             continue;
 641         }
 642         if (se->ops && se->ops->is_active) {
 643             if (!se->ops->is_active(se->opaque)) {
 644                 continue;
 645             }
 646         }
 647         /* Section type */
 648         qemu_put_byte(f, QEMU_VM_SECTION_START);
 649         qemu_put_be32(f, se->section_id);
 650
 651         /* ID string */
 652         len = strlen(se->idstr);
 653         qemu_put_byte(f, len);
 654         qemu_put_buffer(f, (uint8_t *)se->idstr, len);
 655
 656         qemu_put_be32(f, se->instance_id);
 657         qemu_put_be32(f, se->version_id);
 658
 659         ret = se->ops->save_live_setup(f, se->opaque);
 660         if (ret < 0) {
 661             qemu_file_set_error(f, ret);
 662             break;
 663         }
 664     }
 665 }
 666
 667 /*
 668  * this function has three return values:
 669  *   negative: there was one error, and we have -errno.
 670  *   0 : We haven't finished, caller have to go again
 671  *   1 : We have finished, we can go to complete phase
 672  */
 673 int qemu_savevm_state_iterate(QEMUFile *f)
 674 {
 675     SaveStateEntry *se;
 676     int ret = 1;
 677
 678     trace_savevm_state_iterate();
 679     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 680         if (!se->ops || !se->ops->save_live_iterate) {
 681             continue;
 682         }
 683         if (se->ops && se->ops->is_active) {
 684             if (!se->ops->is_active(se->opaque)) {
 685                 continue;
 686             }
 687         }
 688         if (qemu_file_rate_limit(f)) {
 689             return 0;
 690         }
 691         trace_savevm_section_start(se->idstr, se->section_id);
 692         /* Section type */
 693         qemu_put_byte(f, QEMU_VM_SECTION_PART);
 694         qemu_put_be32(f, se->section_id);
 695
 696         ret = se->ops->save_live_iterate(f, se->opaque);
 697         trace_savevm_section_end(se->idstr, se->section_id, ret);
 698
 699         if (ret < 0) {
 700             qemu_file_set_error(f, ret);
 701         }
 702         if (ret <= 0) {
 703             /* Do not proceed to the next vmstate before this one reported
 704                completion of the current stage. This serializes the migration
 705                and reduces the probability that a faster changing state is
 706                synchronized over and over again. */
 707             break;
 708         }
 709     }
 710     return ret;
 711 }
 712
 713 static bool should_send_vmdesc(void)
 714 {
 715     MachineState *machine = MACHINE(qdev_get_machine());
 716     return !machine->suppress_vmdesc;
 717 }
 718
 719 void qemu_savevm_state_complete(QEMUFile *f)
 720 {
 721     QJSON *vmdesc;
 722     int vmdesc_len;
 723     SaveStateEntry *se;
 724     int ret;
 725
 726     trace_savevm_state_complete();
 727
 728     cpu_synchronize_all_states();
 729
 730     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 731         if (!se->ops || !se->ops->save_live_complete) {
 732             continue;
 733         }
 734         if (se->ops && se->ops->is_active) {
 735             if (!se->ops->is_active(se->opaque)) {
 736                 continue;
 737             }
 738         }
 739         trace_savevm_section_start(se->idstr, se->section_id);
 740         /* Section type */
 741         qemu_put_byte(f, QEMU_VM_SECTION_END);
 742         qemu_put_be32(f, se->section_id);
 743
 744         ret = se->ops->save_live_complete(f, se->opaque);
 745         trace_savevm_section_end(se->idstr, se->section_id, ret);
 746         if (ret < 0) {
 747             qemu_file_set_error(f, ret);
 748             return;
 749         }
 750     }
 751
 752     vmdesc = qjson_new();
 753     json_prop_int(vmdesc, "page_size", TARGET_PAGE_SIZE);
 754     json_start_array(vmdesc, "devices");
 755     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 756         int len;
 757
 758         if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
 759             continue;
 760         }
 761         trace_savevm_section_start(se->idstr, se->section_id);
 762
 763         json_start_object(vmdesc, NULL);
 764         json_prop_str(vmdesc, "name", se->idstr);
 765         json_prop_int(vmdesc, "instance_id", se->instance_id);
 766
 767         /* Section type */
 768         qemu_put_byte(f, QEMU_VM_SECTION_FULL);
 769         qemu_put_be32(f, se->section_id);
 770
 771         /* ID string */
 772         len = strlen(se->idstr);
 773         qemu_put_byte(f, len);
 774         qemu_put_buffer(f, (uint8_t *)se->idstr, len);
 775
 776         qemu_put_be32(f, se->instance_id);
 777         qemu_put_be32(f, se->version_id);
 778
 779         vmstate_save(f, se, vmdesc);
 780
 781         json_end_object(vmdesc);
 782         trace_savevm_section_end(se->idstr, se->section_id, 0);
 783     }
 784
 785     qemu_put_byte(f, QEMU_VM_EOF);
 786
 787     json_end_array(vmdesc);
 788     qjson_finish(vmdesc);
 789     vmdesc_len = strlen(qjson_get_str(vmdesc));
 790
 791     if (should_send_vmdesc()) {
 792         qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
 793         qemu_put_be32(f, vmdesc_len);
 794         qemu_put_buffer(f, (uint8_t *)qjson_get_str(vmdesc), vmdesc_len);
 795     }
 796     object_unref(OBJECT(vmdesc));
 797
 798     qemu_fflush(f);
 799 }
 800
 801 uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
 802 {
 803     SaveStateEntry *se;
 804     uint64_t ret = 0;
 805
 806     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 807         if (!se->ops || !se->ops->save_live_pending) {
 808             continue;
 809         }
 810         if (se->ops && se->ops->is_active) {
 811             if (!se->ops->is_active(se->opaque)) {
 812                 continue;
 813             }
 814         }
 815         ret += se->ops->save_live_pending(f, se->opaque, max_size);
 816     }
 817     return ret;
 818 }
 819
 820 void qemu_savevm_state_cancel(void)
 821 {
 822     SaveStateEntry *se;
 823
 824     trace_savevm_state_cancel();
 825     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 826         if (se->ops && se->ops->cancel) {
 827             se->ops->cancel(se->opaque);
 828         }
 829     }
 830 }
 831
 832 static int qemu_savevm_state(QEMUFile *f, Error **errp)
 833 {
 834     int ret;
 835     MigrationParams params = {
 836         .blk = 0,
 837         .shared = 0
 838     };
 839
 840     if (qemu_savevm_state_blocked(errp)) {
 841         return -EINVAL;
 842     }
 843
 844     qemu_mutex_unlock_iothread();
 845     qemu_savevm_state_begin(f, &params);
 846     qemu_mutex_lock_iothread();
 847
 848     while (qemu_file_get_error(f) == 0) {
 849         if (qemu_savevm_state_iterate(f) > 0) {
 850             break;
 851         }
 852     }
 853
 854     ret = qemu_file_get_error(f);
 855     if (ret == 0) {
 856         qemu_savevm_state_complete(f);
 857         ret = qemu_file_get_error(f);
 858     }
 859     if (ret != 0) {
 860         qemu_savevm_state_cancel();
 861         error_setg_errno(errp, -ret, "Error while writing VM state");
 862     }
 863     return ret;
 864 }
 865
 866 static int qemu_save_device_state(QEMUFile *f)
 867 {
 868     SaveStateEntry *se;
 869
 870     qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
 871     qemu_put_be32(f, QEMU_VM_FILE_VERSION);
 872
 873     cpu_synchronize_all_states();
 874
 875     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 876         int len;
 877
 878         if (se->is_ram) {
 879             continue;
 880         }
 881         if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
 882             continue;
 883         }
 884
 885         /* Section type */
 886         qemu_put_byte(f, QEMU_VM_SECTION_FULL);
 887         qemu_put_be32(f, se->section_id);
 888
 889         /* ID string */
 890         len = strlen(se->idstr);
 891         qemu_put_byte(f, len);
 892         qemu_put_buffer(f, (uint8_t *)se->idstr, len);
 893
 894         qemu_put_be32(f, se->instance_id);
 895         qemu_put_be32(f, se->version_id);
 896
 897         vmstate_save(f, se, NULL);
 898     }
 899
 900     qemu_put_byte(f, QEMU_VM_EOF);
 901
 902     return qemu_file_get_error(f);
 903 }
 904
 905 static SaveStateEntry *find_se(const char *idstr, int instance_id)
 906 {
 907     SaveStateEntry *se;
 908
 909     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 910         if (!strcmp(se->idstr, idstr) &&
 911             (instance_id == se->instance_id ||
 912              instance_id == se->alias_id))
 913             return se;
 914         /* Migrating from an older version? */
 915         if (strstr(se->idstr, idstr) && se->compat) {
 916             if (!strcmp(se->compat->idstr, idstr) &&
 917                 (instance_id == se->compat->instance_id ||
 918                  instance_id == se->alias_id))
 919                 return se;
 920         }
 921     }
 922     return NULL;
 923 }
 924
 925 typedef struct LoadStateEntry {
 926     QLIST_ENTRY(LoadStateEntry) entry;
 927     SaveStateEntry *se;
 928     int section_id;
 929     int version_id;
 930 } LoadStateEntry;
 931
 932 int qemu_loadvm_state(QEMUFile *f)
 933 {
 934     QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
 935         QLIST_HEAD_INITIALIZER(loadvm_handlers);
 936     LoadStateEntry *le, *new_le;
 937     Error *local_err = NULL;
 938     uint8_t section_type;
 939     unsigned int v;
 940     int ret;
 941     int file_error_after_eof = -1;
 942
 943     if (qemu_savevm_state_blocked(&local_err)) {
 944         error_report("%s", error_get_pretty(local_err));
 945         error_free(local_err);
 946         return -EINVAL;
 947     }
 948
 949     v = qemu_get_be32(f);
 950     if (v != QEMU_VM_FILE_MAGIC) {
 951         error_report("Not a migration stream");
 952         return -EINVAL;
 953     }
 954
 955     v = qemu_get_be32(f);
 956     if (v == QEMU_VM_FILE_VERSION_COMPAT) {
 957         error_report("SaveVM v2 format is obsolete and don't work anymore");
 958         return -ENOTSUP;
 959     }
 960     if (v != QEMU_VM_FILE_VERSION) {
 961         error_report("Unsupported migration stream version");
 962         return -ENOTSUP;
 963     }
 964
 965     while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
 966         uint32_t instance_id, version_id, section_id;
 967         SaveStateEntry *se;
 968         char idstr[257];
 969         int len;
 970
 971         trace_qemu_loadvm_state_section(section_type);
 972         switch (section_type) {
 973         case QEMU_VM_SECTION_START:
 974         case QEMU_VM_SECTION_FULL:
 975             /* Read section start */
 976             section_id = qemu_get_be32(f);
 977             len = qemu_get_byte(f);
 978             qemu_get_buffer(f, (uint8_t *)idstr, len);
 979             idstr[len] = 0;
 980             instance_id = qemu_get_be32(f);
 981             version_id = qemu_get_be32(f);
 982
 983             trace_qemu_loadvm_state_section_startfull(section_id, idstr,
 984                                                       instance_id, version_id);
 985             /* Find savevm section */
 986             se = find_se(idstr, instance_id);
 987             if (se == NULL) {
 988                 error_report("Unknown savevm section or instance '%s' %d",
 989                              idstr, instance_id);
 990                 ret = -EINVAL;
 991                 goto out;
 992             }
 993
 994             /* Validate version */
 995             if (version_id > se->version_id) {
 996                 error_report("savevm: unsupported version %d for '%s' v%d",
 997                              version_id, idstr, se->version_id);
 998                 ret = -EINVAL;
 999                 goto out;
1000             }
1001
1002             /* Add entry */
1003             le = g_malloc0(sizeof(*le));
1004
1005             le->se = se;
1006             le->section_id = section_id;
1007             le->version_id = version_id;
1008             QLIST_INSERT_HEAD(&loadvm_handlers, le, entry);
1009
1010             ret = vmstate_load(f, le->se, le->version_id);
1011             if (ret < 0) {
1012                 error_report("error while loading state for instance 0x%x of"
1013                              " device '%s'", instance_id, idstr);
1014                 goto out;
1015             }
1016             break;
1017         case QEMU_VM_SECTION_PART:
1018         case QEMU_VM_SECTION_END:
1019             section_id = qemu_get_be32(f);
1020
1021             trace_qemu_loadvm_state_section_partend(section_id);
1022             QLIST_FOREACH(le, &loadvm_handlers, entry) {
1023                 if (le->section_id == section_id) {
1024                     break;
1025                 }
1026             }
1027             if (le == NULL) {
1028                 error_report("Unknown savevm section %d", section_id);
1029                 ret = -EINVAL;
1030                 goto out;
1031             }
1032
1033             ret = vmstate_load(f, le->se, le->version_id);
1034             if (ret < 0) {
1035                 error_report("error while loading state section id %d(%s)",
1036                              section_id, le->se->idstr);
1037                 goto out;
1038             }
1039             break;
1040         default:
1041             error_report("Unknown savevm section type %d", section_type);
1042             ret = -EINVAL;
1043             goto out;
1044         }
1045     }
1046
1047     file_error_after_eof = qemu_file_get_error(f);
1048
1049     /*
1050      * Try to read in the VMDESC section as well, so that dumping tools that
1051      * intercept our migration stream have the chance to see it.
1052      */
1053     if (qemu_get_byte(f) == QEMU_VM_VMDESCRIPTION) {
1054         uint32_t size = qemu_get_be32(f);
1055         uint8_t *buf = g_malloc(0x1000);
1056
1057         while (size > 0) {
1058             uint32_t read_chunk = MIN(size, 0x1000);
1059             qemu_get_buffer(f, buf, read_chunk);
1060             size -= read_chunk;
1061         }
1062         g_free(buf);
1063     }
1064
1065     cpu_synchronize_all_post_init();
1066
1067     ret = 0;
1068
1069 out:
1070     QLIST_FOREACH_SAFE(le, &loadvm_handlers, entry, new_le) {
1071         QLIST_REMOVE(le, entry);
1072         g_free(le);
1073     }
1074
1075     if (ret == 0) {
1076         /* We may not have a VMDESC section, so ignore relative errors */
1077         ret = file_error_after_eof;
1078     }
1079
1080     return ret;
1081 }
1082
1083 static BlockDriverState *find_vmstate_bs(void)
1084 {
1085     BlockDriverState *bs = NULL;
1086     while ((bs = bdrv_next(bs))) {
1087         if (bdrv_can_snapshot(bs)) {
1088             return bs;
1089         }
1090     }
1091     return NULL;
1092 }
1093
1094 /*
1095  * Deletes snapshots of a given name in all opened images.
1096  */
1097 static int del_existing_snapshots(Monitor *mon, const char *name)
1098 {
1099     BlockDriverState *bs;
1100     QEMUSnapshotInfo sn1, *snapshot = &sn1;
1101     Error *err = NULL;
1102
1103     bs = NULL;
1104     while ((bs = bdrv_next(bs))) {
1105         if (bdrv_can_snapshot(bs) &&
1106             bdrv_snapshot_find(bs, snapshot, name) >= 0) {
1107             bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
1108             if (err) {
1109                 monitor_printf(mon,
1110                                "Error while deleting snapshot on device '%s':"
1111                                " %s\n",
1112                                bdrv_get_device_name(bs),
1113                                error_get_pretty(err));
1114                 error_free(err);
1115                 return -1;
1116             }
1117         }
1118     }
1119
1120     return 0;
1121 }
1122
1123 void hmp_savevm(Monitor *mon, const QDict *qdict)
1124 {
1125     BlockDriverState *bs, *bs1;
1126     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
1127     int ret;
1128     QEMUFile *f;
1129     int saved_vm_running;
1130     uint64_t vm_state_size;
1131     qemu_timeval tv;
1132     struct tm tm;
1133     const char *name = qdict_get_try_str(qdict, "name");
1134     Error *local_err = NULL;
1135
1136     /* Verify if there is a device that doesn't support snapshots and is writable */
1137     bs = NULL;
1138     while ((bs = bdrv_next(bs))) {
1139
1140         if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
1141             continue;
1142         }
1143
1144         if (!bdrv_can_snapshot(bs)) {
1145             monitor_printf(mon, "Device '%s' is writable but does not support snapshots.\n",
1146                                bdrv_get_device_name(bs));
1147             return;
1148         }
1149     }
1150
1151     bs = find_vmstate_bs();
1152     if (!bs) {
1153         monitor_printf(mon, "No block device can accept snapshots\n");
1154         return;
1155     }
1156
1157     saved_vm_running = runstate_is_running();
1158     vm_stop(RUN_STATE_SAVE_VM);
1159
1160     memset(sn, 0, sizeof(*sn));
1161
1162     /* fill auxiliary fields */
1163     qemu_gettimeofday(&tv);
1164     sn->date_sec = tv.tv_sec;
1165     sn->date_nsec = tv.tv_usec * 1000;
1166     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
1167
1168     if (name) {
1169         ret = bdrv_snapshot_find(bs, old_sn, name);
1170         if (ret >= 0) {
1171             pstrcpy(sn->name, sizeof(sn->name), old_sn->name);
1172             pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str);
1173         } else {
1174             pstrcpy(sn->name, sizeof(sn->name), name);
1175         }
1176     } else {
1177         /* cast below needed for OpenBSD where tv_sec is still 'long' */
1178         localtime_r((const time_t *)&tv.tv_sec, &tm);
1179         strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm);
1180     }
1181
1182     /* Delete old snapshots of the same name */
1183     if (name && del_existing_snapshots(mon, name) < 0) {
1184         goto the_end;
1185     }
1186
1187     /* save the VM state */
1188     f = qemu_fopen_bdrv(bs, 1);
1189     if (!f) {
1190         monitor_printf(mon, "Could not open VM state file\n");
1191         goto the_end;
1192     }
1193     ret = qemu_savevm_state(f, &local_err);
1194     vm_state_size = qemu_ftell(f);
1195     qemu_fclose(f);
1196     if (ret < 0) {
1197         monitor_printf(mon, "%s\n", error_get_pretty(local_err));
1198         error_free(local_err);
1199         goto the_end;
1200     }
1201
1202     /* create the snapshots */
1203
1204     bs1 = NULL;
1205     while ((bs1 = bdrv_next(bs1))) {
1206         if (bdrv_can_snapshot(bs1)) {
1207             /* Write VM state size only to the image that contains the state */
1208             sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
1209             ret = bdrv_snapshot_create(bs1, sn);
1210             if (ret < 0) {
1211                 monitor_printf(mon, "Error while creating snapshot on '%s'\n",
1212                                bdrv_get_device_name(bs1));
1213             }
1214         }
1215     }
1216
1217  the_end:
1218     if (saved_vm_running) {
1219         vm_start();
1220     }
1221 }
1222
1223 void qmp_xen_save_devices_state(const char *filename, Error **errp)
1224 {
1225     QEMUFile *f;
1226     int saved_vm_running;
1227     int ret;
1228
1229     saved_vm_running = runstate_is_running();
1230     vm_stop(RUN_STATE_SAVE_VM);
1231
1232     f = qemu_fopen(filename, "wb");
1233     if (!f) {
1234         error_setg_file_open(errp, errno, filename);
1235         goto the_end;
1236     }
1237     ret = qemu_save_device_state(f);
1238     qemu_fclose(f);
1239     if (ret < 0) {
1240         error_set(errp, QERR_IO_ERROR);
1241     }
1242
1243  the_end:
1244     if (saved_vm_running) {
1245         vm_start();
1246     }
1247 }
1248
1249 int load_vmstate(const char *name)
1250 {
1251     BlockDriverState *bs, *bs_vm_state;
1252     QEMUSnapshotInfo sn;
1253     QEMUFile *f;
1254     int ret;
1255
1256     bs_vm_state = find_vmstate_bs();
1257     if (!bs_vm_state) {
1258         error_report("No block device supports snapshots");
1259         return -ENOTSUP;
1260     }
1261
1262     /* Don't even try to load empty VM states */
1263     ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
1264     if (ret < 0) {
1265         return ret;
1266     } else if (sn.vm_state_size == 0) {
1267         error_report("This is a disk-only snapshot. Revert to it offline "
1268             "using qemu-img.");
1269         return -EINVAL;
1270     }
1271
1272     /* Verify if there is any device that doesn't support snapshots and is
1273     writable and check if the requested snapshot is available too. */
1274     bs = NULL;
1275     while ((bs = bdrv_next(bs))) {
1276
1277         if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
1278             continue;
1279         }
1280
1281         if (!bdrv_can_snapshot(bs)) {
1282             error_report("Device '%s' is writable but does not support snapshots.",
1283                                bdrv_get_device_name(bs));
1284             return -ENOTSUP;
1285         }
1286
1287         ret = bdrv_snapshot_find(bs, &sn, name);
1288         if (ret < 0) {
1289             error_report("Device '%s' does not have the requested snapshot '%s'",
1290                            bdrv_get_device_name(bs), name);
1291             return ret;
1292         }
1293     }
1294
1295     /* Flush all IO requests so they don't interfere with the new state.  */
1296     bdrv_drain_all();
1297
1298     bs = NULL;
1299     while ((bs = bdrv_next(bs))) {
1300         if (bdrv_can_snapshot(bs)) {
1301             ret = bdrv_snapshot_goto(bs, name);
1302             if (ret < 0) {
1303                 error_report("Error %d while activating snapshot '%s' on '%s'",
1304                              ret, name, bdrv_get_device_name(bs));
1305                 return ret;
1306             }
1307         }
1308     }
1309
1310     /* restore the VM state */
1311     f = qemu_fopen_bdrv(bs_vm_state, 0);
1312     if (!f) {
1313         error_report("Could not open VM state file");
1314         return -EINVAL;
1315     }
1316
1317     qemu_system_reset(VMRESET_SILENT);
1318     ret = qemu_loadvm_state(f);
1319
1320     qemu_fclose(f);
1321     if (ret < 0) {
1322         error_report("Error %d while loading VM state", ret);
1323         return ret;
1324     }
1325
1326     return 0;
1327 }
1328
1329 void hmp_delvm(Monitor *mon, const QDict *qdict)
1330 {
1331     BlockDriverState *bs;
1332     Error *err;
1333     const char *name = qdict_get_str(qdict, "name");
1334
1335     if (!find_vmstate_bs()) {
1336         monitor_printf(mon, "No block device supports snapshots\n");
1337         return;
1338     }
1339
1340     bs = NULL;
1341     while ((bs = bdrv_next(bs))) {
1342         if (bdrv_can_snapshot(bs)) {
1343             err = NULL;
1344             bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
1345             if (err) {
1346                 monitor_printf(mon,
1347                                "Error while deleting snapshot on device '%s':"
1348                                " %s\n",
1349                                bdrv_get_device_name(bs),
1350                                error_get_pretty(err));
1351                 error_free(err);
1352             }
1353         }
1354     }
1355 }
1356
1357 void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
1358 {
1359     BlockDriverState *bs, *bs1;
1360     QEMUSnapshotInfo *sn_tab, *sn, s, *sn_info = &s;
1361     int nb_sns, i, ret, available;
1362     int total;
1363     int *available_snapshots;
1364
1365     bs = find_vmstate_bs();
1366     if (!bs) {
1367         monitor_printf(mon, "No available block device supports snapshots\n");
1368         return;
1369     }
1370
1371     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
1372     if (nb_sns < 0) {
1373         monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns);
1374         return;
1375     }
1376
1377     if (nb_sns == 0) {
1378         monitor_printf(mon, "There is no snapshot available.\n");
1379         return;
1380     }
1381
1382     available_snapshots = g_malloc0(sizeof(int) * nb_sns);
1383     total = 0;
1384     for (i = 0; i < nb_sns; i++) {
1385         sn = &sn_tab[i];
1386         available = 1;
1387         bs1 = NULL;
1388
1389         while ((bs1 = bdrv_next(bs1))) {
1390             if (bdrv_can_snapshot(bs1) && bs1 != bs) {
1391                 ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str);
1392                 if (ret < 0) {
1393                     available = 0;
1394                     break;
1395                 }
1396             }
1397         }
1398
1399         if (available) {
1400             available_snapshots[total] = i;
1401             total++;
1402         }
1403     }
1404
1405     if (total > 0) {
1406         bdrv_snapshot_dump((fprintf_function)monitor_printf, mon, NULL);
1407         monitor_printf(mon, "\n");
1408         for (i = 0; i < total; i++) {
1409             sn = &sn_tab[available_snapshots[i]];
1410             bdrv_snapshot_dump((fprintf_function)monitor_printf, mon, sn);
1411             monitor_printf(mon, "\n");
1412         }
1413     } else {
1414         monitor_printf(mon, "There is no suitable snapshot available\n");
1415     }
1416
1417     g_free(sn_tab);
1418     g_free(available_snapshots);
1419
1420 }
1421
1422 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
1423 {
1424     qemu_ram_set_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK,
1425                        memory_region_name(mr), dev);
1426 }
1427
1428 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
1429 {
1430     qemu_ram_unset_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
1431 }
1432
1433 void vmstate_register_ram_global(MemoryRegion *mr)
1434 {
1435     vmstate_register_ram(mr, NULL);
1436 }