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 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <time.h>
  27 #include <errno.h>
  28 #include <sys/time.h>
  29 #include <zlib.h>
  30
  31 /* Needed early for CONFIG_BSD etc. */
  32 #include "config-host.h"
  33
  34 #ifndef _WIN32
  35 #include <sys/times.h>
  36 #include <sys/wait.h>
  37 #include <termios.h>
  38 #include <sys/mman.h>
  39 #include <sys/ioctl.h>
  40 #include <sys/resource.h>
  41 #include <sys/socket.h>
  42 #include <netinet/in.h>
  43 #include <net/if.h>
  44 #include <arpa/inet.h>
  45 #include <dirent.h>
  46 #include <netdb.h>
  47 #include <sys/select.h>
  48 #ifdef CONFIG_BSD
  49 #include <sys/stat.h>
  50 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
  51 #include <libutil.h>
  52 #else
  53 #include <util.h>
  54 #endif
  55 #ifdef __linux__
  56 #include <pty.h>
  57 #include <malloc.h>
  58 #include <linux/rtc.h>
  59 #endif
  60 #endif
  61 #endif
  62
  63 #ifdef _WIN32
  64 #include <windows.h>
  65 #include <malloc.h>
  66 #include <sys/timeb.h>
  67 #include <mmsystem.h>
  68 #define getopt_long_only getopt_long
  69 #define memalign(align, size) malloc(size)
  70 #endif
  71
  72 #include "qemu-common.h"
  73 #include "hw/hw.h"
  74 #include "hw/qdev.h"
  75 #include "net.h"
  76 #include "monitor.h"
  77 #include "sysemu.h"
  78 #include "qemu-timer.h"
  79 #include "qemu-char.h"
  80 #include "audio/audio.h"
  81 #include "migration.h"
  82 #include "qemu_socket.h"
  83 #include "qemu-queue.h"
  84 #include "cpus.h"
  85
  86 #define SELF_ANNOUNCE_ROUNDS 5
  87
  88 #ifndef ETH_P_RARP
  89 #define ETH_P_RARP 0x8035
  90 #endif
  91 #define ARP_HTYPE_ETH 0x0001
  92 #define ARP_PTYPE_IP 0x0800
  93 #define ARP_OP_REQUEST_REV 0x3
  94
  95 static int announce_self_create(uint8_t *buf,
  96                                 uint8_t *mac_addr)
  97 {
  98     /* Ethernet header. */
  99     memset(buf, 0xff, 6);         /* destination MAC addr */
 100     memcpy(buf + 6, mac_addr, 6); /* source MAC addr */
 101     *(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */
 102
 103     /* RARP header. */
 104     *(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */
 105     *(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */
 106     *(buf + 18) = 6; /* hardware addr length (ethernet) */
 107     *(buf + 19) = 4; /* protocol addr length (IPv4) */
 108     *(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */
 109     memcpy(buf + 22, mac_addr, 6); /* source hw addr */
 110     memset(buf + 28, 0x00, 4);     /* source protocol addr */
 111     memcpy(buf + 32, mac_addr, 6); /* target hw addr */
 112     memset(buf + 38, 0x00, 4);     /* target protocol addr */
 113
 114     /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
 115     memset(buf + 42, 0x00, 18);
 116
 117     return 60; /* len (FCS will be added by hardware) */
 118 }
 119
 120 static void qemu_announce_self_iter(NICState *nic, void *opaque)
 121 {
 122     uint8_t buf[60];
 123     int len;
 124
 125     len = announce_self_create(buf, nic->conf->macaddr.a);
 126
 127     qemu_send_packet_raw(&nic->nc, buf, len);
 128 }
 129
 130
 131 static void qemu_announce_self_once(void *opaque)
 132 {
 133     static int count = SELF_ANNOUNCE_ROUNDS;
 134     QEMUTimer *timer = *(QEMUTimer **)opaque;
 135
 136     qemu_foreach_nic(qemu_announce_self_iter, NULL);
 137
 138     if (--count) {
 139         /* delay 50ms, 150ms, 250ms, ... */
 140         qemu_mod_timer(timer, qemu_get_clock_ms(rt_clock) +
 141                        50 + (SELF_ANNOUNCE_ROUNDS - count - 1) * 100);
 142     } else {
 143             qemu_del_timer(timer);
 144             qemu_free_timer(timer);
 145     }
 146 }
 147
 148 void qemu_announce_self(void)
 149 {
 150         static QEMUTimer *timer;
 151         timer = qemu_new_timer_ms(rt_clock, qemu_announce_self_once, &timer);
 152         qemu_announce_self_once(&timer);
 153 }
 154
 155 /***********************************************************/
 156 /* savevm/loadvm support */
 157
 158 #define IO_BUF_SIZE 32768
 159
 160 struct QEMUFile {
 161     QEMUFilePutBufferFunc *put_buffer;
 162     QEMUFileGetBufferFunc *get_buffer;
 163     QEMUFileCloseFunc *close;
 164     QEMUFileRateLimit *rate_limit;
 165     QEMUFileSetRateLimit *set_rate_limit;
 166     QEMUFileGetRateLimit *get_rate_limit;
 167     void *opaque;
 168     int is_write;
 169
 170     int64_t buf_offset; /* start of buffer when writing, end of buffer
 171                            when reading */
 172     int buf_index;
 173     int buf_size; /* 0 when writing */
 174     uint8_t buf[IO_BUF_SIZE];
 175
 176     int has_error;
 177 };
 178
 179 typedef struct QEMUFileStdio
 180 {
 181     FILE *stdio_file;
 182     QEMUFile *file;
 183 } QEMUFileStdio;
 184
 185 typedef struct QEMUFileSocket
 186 {
 187     int fd;
 188     QEMUFile *file;
 189 } QEMUFileSocket;
 190
 191 static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
 192 {
 193     QEMUFileSocket *s = opaque;
 194     ssize_t len;
 195
 196     do {
 197         len = recv(s->fd, (void *)buf, size, 0);
 198     } while (len == -1 && socket_error() == EINTR);
 199
 200     if (len == -1)
 201         len = -socket_error();
 202
 203     return len;
 204 }
 205
 206 static int socket_close(void *opaque)
 207 {
 208     QEMUFileSocket *s = opaque;
 209     qemu_free(s);
 210     return 0;
 211 }
 212
 213 static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
 214 {
 215     QEMUFileStdio *s = opaque;
 216     return fwrite(buf, 1, size, s->stdio_file);
 217 }
 218
 219 static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
 220 {
 221     QEMUFileStdio *s = opaque;
 222     FILE *fp = s->stdio_file;
 223     int bytes;
 224
 225     do {
 226         clearerr(fp);
 227         bytes = fread(buf, 1, size, fp);
 228     } while ((bytes == 0) && ferror(fp) && (errno == EINTR));
 229     return bytes;
 230 }
 231
 232 static int stdio_pclose(void *opaque)
 233 {
 234     QEMUFileStdio *s = opaque;
 235     int ret;
 236     ret = pclose(s->stdio_file);
 237     qemu_free(s);
 238     return ret;
 239 }
 240
 241 static int stdio_fclose(void *opaque)
 242 {
 243     QEMUFileStdio *s = opaque;
 244     fclose(s->stdio_file);
 245     qemu_free(s);
 246     return 0;
 247 }
 248
 249 QEMUFile *qemu_popen(FILE *stdio_file, const char *mode)
 250 {
 251     QEMUFileStdio *s;
 252
 253     if (stdio_file == NULL || mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
 254         fprintf(stderr, "qemu_popen: Argument validity check failed\n");
 255         return NULL;
 256     }
 257
 258     s = qemu_mallocz(sizeof(QEMUFileStdio));
 259
 260     s->stdio_file = stdio_file;
 261
 262     if(mode[0] == 'r') {
 263         s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_pclose,
 264                                  NULL, NULL, NULL);
 265     } else {
 266         s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_pclose,
 267                                  NULL, NULL, NULL);
 268     }
 269     return s->file;
 270 }
 271
 272 QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
 273 {
 274     FILE *popen_file;
 275
 276     popen_file = popen(command, mode);
 277     if(popen_file == NULL) {
 278         return NULL;
 279     }
 280
 281     return qemu_popen(popen_file, mode);
 282 }
 283
 284 int qemu_stdio_fd(QEMUFile *f)
 285 {
 286     QEMUFileStdio *p;
 287     int fd;
 288
 289     p = (QEMUFileStdio *)f->opaque;
 290     fd = fileno(p->stdio_file);
 291
 292     return fd;
 293 }
 294
 295 QEMUFile *qemu_fdopen(int fd, const char *mode)
 296 {
 297     QEMUFileStdio *s;
 298
 299     if (mode == NULL ||
 300         (mode[0] != 'r' && mode[0] != 'w') ||
 301         mode[1] != 'b' || mode[2] != 0) {
 302         fprintf(stderr, "qemu_fdopen: Argument validity check failed\n");
 303         return NULL;
 304     }
 305
 306     s = qemu_mallocz(sizeof(QEMUFileStdio));
 307     s->stdio_file = fdopen(fd, mode);
 308     if (!s->stdio_file)
 309         goto fail;
 310
 311     if(mode[0] == 'r') {
 312         s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_fclose,
 313                                  NULL, NULL, NULL);
 314     } else {
 315         s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_fclose,
 316                                  NULL, NULL, NULL);
 317     }
 318     return s->file;
 319
 320 fail:
 321     qemu_free(s);
 322     return NULL;
 323 }
 324
 325 QEMUFile *qemu_fopen_socket(int fd)
 326 {
 327     QEMUFileSocket *s = qemu_mallocz(sizeof(QEMUFileSocket));
 328
 329     s->fd = fd;
 330     s->file = qemu_fopen_ops(s, NULL, socket_get_buffer, socket_close,
 331                              NULL, NULL, NULL);
 332     return s->file;
 333 }
 334
 335 static int file_put_buffer(void *opaque, const uint8_t *buf,
 336                             int64_t pos, int size)
 337 {
 338     QEMUFileStdio *s = opaque;
 339     fseek(s->stdio_file, pos, SEEK_SET);
 340     return fwrite(buf, 1, size, s->stdio_file);
 341 }
 342
 343 static int file_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
 344 {
 345     QEMUFileStdio *s = opaque;
 346     fseek(s->stdio_file, pos, SEEK_SET);
 347     return fread(buf, 1, size, s->stdio_file);
 348 }
 349
 350 QEMUFile *qemu_fopen(const char *filename, const char *mode)
 351 {
 352     QEMUFileStdio *s;
 353
 354     if (mode == NULL ||
 355         (mode[0] != 'r' && mode[0] != 'w') ||
 356         mode[1] != 'b' || mode[2] != 0) {
 357         fprintf(stderr, "qemu_fopen: Argument validity check failed\n");
 358         return NULL;
 359     }
 360
 361     s = qemu_mallocz(sizeof(QEMUFileStdio));
 362
 363     s->stdio_file = fopen(filename, mode);
 364     if (!s->stdio_file)
 365         goto fail;
 366
 367     if(mode[0] == 'w') {
 368         s->file = qemu_fopen_ops(s, file_put_buffer, NULL, stdio_fclose,
 369                                  NULL, NULL, NULL);
 370     } else {
 371         s->file = qemu_fopen_ops(s, NULL, file_get_buffer, stdio_fclose,
 372                                NULL, NULL, NULL);
 373     }
 374     return s->file;
 375 fail:
 376     qemu_free(s);
 377     return NULL;
 378 }
 379
 380 static int block_put_buffer(void *opaque, const uint8_t *buf,
 381                            int64_t pos, int size)
 382 {
 383     bdrv_save_vmstate(opaque, buf, pos, size);
 384     return size;
 385 }
 386
 387 static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
 388 {
 389     return bdrv_load_vmstate(opaque, buf, pos, size);
 390 }
 391
 392 static int bdrv_fclose(void *opaque)
 393 {
 394     return 0;
 395 }
 396
 397 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
 398 {
 399     if (is_writable)
 400         return qemu_fopen_ops(bs, block_put_buffer, NULL, bdrv_fclose,
 401                               NULL, NULL, NULL);
 402     return qemu_fopen_ops(bs, NULL, block_get_buffer, bdrv_fclose, NULL, NULL, NULL);
 403 }
 404
 405 QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
 406                          QEMUFileGetBufferFunc *get_buffer,
 407                          QEMUFileCloseFunc *close,
 408                          QEMUFileRateLimit *rate_limit,
 409                          QEMUFileSetRateLimit *set_rate_limit,
 410                          QEMUFileGetRateLimit *get_rate_limit)
 411 {
 412     QEMUFile *f;
 413
 414     f = qemu_mallocz(sizeof(QEMUFile));
 415
 416     f->opaque = opaque;
 417     f->put_buffer = put_buffer;
 418     f->get_buffer = get_buffer;
 419     f->close = close;
 420     f->rate_limit = rate_limit;
 421     f->set_rate_limit = set_rate_limit;
 422     f->get_rate_limit = get_rate_limit;
 423     f->is_write = 0;
 424
 425     return f;
 426 }
 427
 428 int qemu_file_has_error(QEMUFile *f)
 429 {
 430     return f->has_error;
 431 }
 432
 433 void qemu_file_set_error(QEMUFile *f)
 434 {
 435     f->has_error = 1;
 436 }
 437
 438 void qemu_fflush(QEMUFile *f)
 439 {
 440     if (!f->put_buffer)
 441         return;
 442
 443     if (f->is_write && f->buf_index > 0) {
 444         int len;
 445
 446         len = f->put_buffer(f->opaque, f->buf, f->buf_offset, f->buf_index);
 447         if (len > 0)
 448             f->buf_offset += f->buf_index;
 449         else
 450             f->has_error = 1;
 451         f->buf_index = 0;
 452     }
 453 }
 454
 455 static void qemu_fill_buffer(QEMUFile *f)
 456 {
 457     int len;
 458
 459     if (!f->get_buffer)
 460         return;
 461
 462     if (f->is_write)
 463         abort();
 464
 465     len = f->get_buffer(f->opaque, f->buf, f->buf_offset, IO_BUF_SIZE);
 466     if (len > 0) {
 467         f->buf_index = 0;
 468         f->buf_size = len;
 469         f->buf_offset += len;
 470     } else if (len != -EAGAIN)
 471         f->has_error = 1;
 472 }
 473
 474 int qemu_fclose(QEMUFile *f)
 475 {
 476     int ret = 0;
 477     qemu_fflush(f);
 478     if (f->close)
 479         ret = f->close(f->opaque);
 480     qemu_free(f);
 481     return ret;
 482 }
 483
 484 void qemu_file_put_notify(QEMUFile *f)
 485 {
 486     f->put_buffer(f->opaque, NULL, 0, 0);
 487 }
 488
 489 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
 490 {
 491     int l;
 492
 493     if (!f->has_error && f->is_write == 0 && f->buf_index > 0) {
 494         fprintf(stderr,
 495                 "Attempted to write to buffer while read buffer is not empty\n");
 496         abort();
 497     }
 498
 499     while (!f->has_error && size > 0) {
 500         l = IO_BUF_SIZE - f->buf_index;
 501         if (l > size)
 502             l = size;
 503         memcpy(f->buf + f->buf_index, buf, l);
 504         f->is_write = 1;
 505         f->buf_index += l;
 506         buf += l;
 507         size -= l;
 508         if (f->buf_index >= IO_BUF_SIZE)
 509             qemu_fflush(f);
 510     }
 511 }
 512
 513 void qemu_put_byte(QEMUFile *f, int v)
 514 {
 515     if (!f->has_error && f->is_write == 0 && f->buf_index > 0) {
 516         fprintf(stderr,
 517                 "Attempted to write to buffer while read buffer is not empty\n");
 518         abort();
 519     }
 520
 521     f->buf[f->buf_index++] = v;
 522     f->is_write = 1;
 523     if (f->buf_index >= IO_BUF_SIZE)
 524         qemu_fflush(f);
 525 }
 526
 527 int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size1)
 528 {
 529     int size, l;
 530
 531     if (f->is_write)
 532         abort();
 533
 534     size = size1;
 535     while (size > 0) {
 536         l = f->buf_size - f->buf_index;
 537         if (l == 0) {
 538             qemu_fill_buffer(f);
 539             l = f->buf_size - f->buf_index;
 540             if (l == 0)
 541                 break;
 542         }
 543         if (l > size)
 544             l = size;
 545         memcpy(buf, f->buf + f->buf_index, l);
 546         f->buf_index += l;
 547         buf += l;
 548         size -= l;
 549     }
 550     return size1 - size;
 551 }
 552
 553 static int qemu_peek_byte(QEMUFile *f)
 554 {
 555     if (f->is_write)
 556         abort();
 557
 558     if (f->buf_index >= f->buf_size) {
 559         qemu_fill_buffer(f);
 560         if (f->buf_index >= f->buf_size)
 561             return 0;
 562     }
 563     return f->buf[f->buf_index];
 564 }
 565
 566 int qemu_get_byte(QEMUFile *f)
 567 {
 568     if (f->is_write)
 569         abort();
 570
 571     if (f->buf_index >= f->buf_size) {
 572         qemu_fill_buffer(f);
 573         if (f->buf_index >= f->buf_size)
 574             return 0;
 575     }
 576     return f->buf[f->buf_index++];
 577 }
 578
 579 int64_t qemu_ftell(QEMUFile *f)
 580 {
 581     return f->buf_offset - f->buf_size + f->buf_index;
 582 }
 583
 584 int64_t qemu_fseek(QEMUFile *f, int64_t pos, int whence)
 585 {
 586     if (whence == SEEK_SET) {
 587         /* nothing to do */
 588     } else if (whence == SEEK_CUR) {
 589         pos += qemu_ftell(f);
 590     } else {
 591         /* SEEK_END not supported */
 592         return -1;
 593     }
 594     if (f->put_buffer) {
 595         qemu_fflush(f);
 596         f->buf_offset = pos;
 597     } else {
 598         f->buf_offset = pos;
 599         f->buf_index = 0;
 600         f->buf_size = 0;
 601     }
 602     return pos;
 603 }
 604
 605 int qemu_file_rate_limit(QEMUFile *f)
 606 {
 607     if (f->rate_limit)
 608         return f->rate_limit(f->opaque);
 609
 610     return 0;
 611 }
 612
 613 int64_t qemu_file_get_rate_limit(QEMUFile *f)
 614 {
 615     if (f->get_rate_limit)
 616         return f->get_rate_limit(f->opaque);
 617
 618     return 0;
 619 }
 620
 621 int64_t qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate)
 622 {
 623     /* any failed or completed migration keeps its state to allow probing of
 624      * migration data, but has no associated file anymore */
 625     if (f && f->set_rate_limit)
 626         return f->set_rate_limit(f->opaque, new_rate);
 627
 628     return 0;
 629 }
 630
 631 void qemu_put_be16(QEMUFile *f, unsigned int v)
 632 {
 633     qemu_put_byte(f, v >> 8);
 634     qemu_put_byte(f, v);
 635 }
 636
 637 void qemu_put_be32(QEMUFile *f, unsigned int v)
 638 {
 639     qemu_put_byte(f, v >> 24);
 640     qemu_put_byte(f, v >> 16);
 641     qemu_put_byte(f, v >> 8);
 642     qemu_put_byte(f, v);
 643 }
 644
 645 void qemu_put_be64(QEMUFile *f, uint64_t v)
 646 {
 647     qemu_put_be32(f, v >> 32);
 648     qemu_put_be32(f, v);
 649 }
 650
 651 unsigned int qemu_get_be16(QEMUFile *f)
 652 {
 653     unsigned int v;
 654     v = qemu_get_byte(f) << 8;
 655     v |= qemu_get_byte(f);
 656     return v;
 657 }
 658
 659 unsigned int qemu_get_be32(QEMUFile *f)
 660 {
 661     unsigned int v;
 662     v = qemu_get_byte(f) << 24;
 663     v |= qemu_get_byte(f) << 16;
 664     v |= qemu_get_byte(f) << 8;
 665     v |= qemu_get_byte(f);
 666     return v;
 667 }
 668
 669 uint64_t qemu_get_be64(QEMUFile *f)
 670 {
 671     uint64_t v;
 672     v = (uint64_t)qemu_get_be32(f) << 32;
 673     v |= qemu_get_be32(f);
 674     return v;
 675 }
 676
 677 /* bool */
 678
 679 static int get_bool(QEMUFile *f, void *pv, size_t size)
 680 {
 681     bool *v = pv;
 682     *v = qemu_get_byte(f);
 683     return 0;
 684 }
 685
 686 static void put_bool(QEMUFile *f, void *pv, size_t size)
 687 {
 688     bool *v = pv;
 689     qemu_put_byte(f, *v);
 690 }
 691
 692 const VMStateInfo vmstate_info_bool = {
 693     .name = "bool",
 694     .get  = get_bool,
 695     .put  = put_bool,
 696 };
 697
 698 /* 8 bit int */
 699
 700 static int get_int8(QEMUFile *f, void *pv, size_t size)
 701 {
 702     int8_t *v = pv;
 703     qemu_get_s8s(f, v);
 704     return 0;
 705 }
 706
 707 static void put_int8(QEMUFile *f, void *pv, size_t size)
 708 {
 709     int8_t *v = pv;
 710     qemu_put_s8s(f, v);
 711 }
 712
 713 const VMStateInfo vmstate_info_int8 = {
 714     .name = "int8",
 715     .get  = get_int8,
 716     .put  = put_int8,
 717 };
 718
 719 /* 16 bit int */
 720
 721 static int get_int16(QEMUFile *f, void *pv, size_t size)
 722 {
 723     int16_t *v = pv;
 724     qemu_get_sbe16s(f, v);
 725     return 0;
 726 }
 727
 728 static void put_int16(QEMUFile *f, void *pv, size_t size)
 729 {
 730     int16_t *v = pv;
 731     qemu_put_sbe16s(f, v);
 732 }
 733
 734 const VMStateInfo vmstate_info_int16 = {
 735     .name = "int16",
 736     .get  = get_int16,
 737     .put  = put_int16,
 738 };
 739
 740 /* 32 bit int */
 741
 742 static int get_int32(QEMUFile *f, void *pv, size_t size)
 743 {
 744     int32_t *v = pv;
 745     qemu_get_sbe32s(f, v);
 746     return 0;
 747 }
 748
 749 static void put_int32(QEMUFile *f, void *pv, size_t size)
 750 {
 751     int32_t *v = pv;
 752     qemu_put_sbe32s(f, v);
 753 }
 754
 755 const VMStateInfo vmstate_info_int32 = {
 756     .name = "int32",
 757     .get  = get_int32,
 758     .put  = put_int32,
 759 };
 760
 761 /* 32 bit int. See that the received value is the same than the one
 762    in the field */
 763
 764 static int get_int32_equal(QEMUFile *f, void *pv, size_t size)
 765 {
 766     int32_t *v = pv;
 767     int32_t v2;
 768     qemu_get_sbe32s(f, &v2);
 769
 770     if (*v == v2)
 771         return 0;
 772     return -EINVAL;
 773 }
 774
 775 const VMStateInfo vmstate_info_int32_equal = {
 776     .name = "int32 equal",
 777     .get  = get_int32_equal,
 778     .put  = put_int32,
 779 };
 780
 781 /* 32 bit int. See that the received value is the less or the same
 782    than the one in the field */
 783
 784 static int get_int32_le(QEMUFile *f, void *pv, size_t size)
 785 {
 786     int32_t *old = pv;
 787     int32_t new;
 788     qemu_get_sbe32s(f, &new);
 789
 790     if (*old <= new)
 791         return 0;
 792     return -EINVAL;
 793 }
 794
 795 const VMStateInfo vmstate_info_int32_le = {
 796     .name = "int32 equal",
 797     .get  = get_int32_le,
 798     .put  = put_int32,
 799 };
 800
 801 /* 64 bit int */
 802
 803 static int get_int64(QEMUFile *f, void *pv, size_t size)
 804 {
 805     int64_t *v = pv;
 806     qemu_get_sbe64s(f, v);
 807     return 0;
 808 }
 809
 810 static void put_int64(QEMUFile *f, void *pv, size_t size)
 811 {
 812     int64_t *v = pv;
 813     qemu_put_sbe64s(f, v);
 814 }
 815
 816 const VMStateInfo vmstate_info_int64 = {
 817     .name = "int64",
 818     .get  = get_int64,
 819     .put  = put_int64,
 820 };
 821
 822 /* 8 bit unsigned int */
 823
 824 static int get_uint8(QEMUFile *f, void *pv, size_t size)
 825 {
 826     uint8_t *v = pv;
 827     qemu_get_8s(f, v);
 828     return 0;
 829 }
 830
 831 static void put_uint8(QEMUFile *f, void *pv, size_t size)
 832 {
 833     uint8_t *v = pv;
 834     qemu_put_8s(f, v);
 835 }
 836
 837 const VMStateInfo vmstate_info_uint8 = {
 838     .name = "uint8",
 839     .get  = get_uint8,
 840     .put  = put_uint8,
 841 };
 842
 843 /* 16 bit unsigned int */
 844
 845 static int get_uint16(QEMUFile *f, void *pv, size_t size)
 846 {
 847     uint16_t *v = pv;
 848     qemu_get_be16s(f, v);
 849     return 0;
 850 }
 851
 852 static void put_uint16(QEMUFile *f, void *pv, size_t size)
 853 {
 854     uint16_t *v = pv;
 855     qemu_put_be16s(f, v);
 856 }
 857
 858 const VMStateInfo vmstate_info_uint16 = {
 859     .name = "uint16",
 860     .get  = get_uint16,
 861     .put  = put_uint16,
 862 };
 863
 864 /* 32 bit unsigned int */
 865
 866 static int get_uint32(QEMUFile *f, void *pv, size_t size)
 867 {
 868     uint32_t *v = pv;
 869     qemu_get_be32s(f, v);
 870     return 0;
 871 }
 872
 873 static void put_uint32(QEMUFile *f, void *pv, size_t size)
 874 {
 875     uint32_t *v = pv;
 876     qemu_put_be32s(f, v);
 877 }
 878
 879 const VMStateInfo vmstate_info_uint32 = {
 880     .name = "uint32",
 881     .get  = get_uint32,
 882     .put  = put_uint32,
 883 };
 884
 885 /* 32 bit uint. See that the received value is the same than the one
 886    in the field */
 887
 888 static int get_uint32_equal(QEMUFile *f, void *pv, size_t size)
 889 {
 890     uint32_t *v = pv;
 891     uint32_t v2;
 892     qemu_get_be32s(f, &v2);
 893
 894     if (*v == v2) {
 895         return 0;
 896     }
 897     return -EINVAL;
 898 }
 899
 900 const VMStateInfo vmstate_info_uint32_equal = {
 901     .name = "uint32 equal",
 902     .get  = get_uint32_equal,
 903     .put  = put_uint32,
 904 };
 905
 906 /* 64 bit unsigned int */
 907
 908 static int get_uint64(QEMUFile *f, void *pv, size_t size)
 909 {
 910     uint64_t *v = pv;
 911     qemu_get_be64s(f, v);
 912     return 0;
 913 }
 914
 915 static void put_uint64(QEMUFile *f, void *pv, size_t size)
 916 {
 917     uint64_t *v = pv;
 918     qemu_put_be64s(f, v);
 919 }
 920
 921 const VMStateInfo vmstate_info_uint64 = {
 922     .name = "uint64",
 923     .get  = get_uint64,
 924     .put  = put_uint64,
 925 };
 926
 927 /* 8 bit int. See that the received value is the same than the one
 928    in the field */
 929
 930 static int get_uint8_equal(QEMUFile *f, void *pv, size_t size)
 931 {
 932     uint8_t *v = pv;
 933     uint8_t v2;
 934     qemu_get_8s(f, &v2);
 935
 936     if (*v == v2)
 937         return 0;
 938     return -EINVAL;
 939 }
 940
 941 const VMStateInfo vmstate_info_uint8_equal = {
 942     .name = "uint8 equal",
 943     .get  = get_uint8_equal,
 944     .put  = put_uint8,
 945 };
 946
 947 /* 16 bit unsigned int int. See that the received value is the same than the one
 948    in the field */
 949
 950 static int get_uint16_equal(QEMUFile *f, void *pv, size_t size)
 951 {
 952     uint16_t *v = pv;
 953     uint16_t v2;
 954     qemu_get_be16s(f, &v2);
 955
 956     if (*v == v2)
 957         return 0;
 958     return -EINVAL;
 959 }
 960
 961 const VMStateInfo vmstate_info_uint16_equal = {
 962     .name = "uint16 equal",
 963     .get  = get_uint16_equal,
 964     .put  = put_uint16,
 965 };
 966
 967 /* timers  */
 968
 969 static int get_timer(QEMUFile *f, void *pv, size_t size)
 970 {
 971     QEMUTimer *v = pv;
 972     qemu_get_timer(f, v);
 973     return 0;
 974 }
 975
 976 static void put_timer(QEMUFile *f, void *pv, size_t size)
 977 {
 978     QEMUTimer *v = pv;
 979     qemu_put_timer(f, v);
 980 }
 981
 982 const VMStateInfo vmstate_info_timer = {
 983     .name = "timer",
 984     .get  = get_timer,
 985     .put  = put_timer,
 986 };
 987
 988 /* uint8_t buffers */
 989
 990 static int get_buffer(QEMUFile *f, void *pv, size_t size)
 991 {
 992     uint8_t *v = pv;
 993     qemu_get_buffer(f, v, size);
 994     return 0;
 995 }
 996
 997 static void put_buffer(QEMUFile *f, void *pv, size_t size)
 998 {
 999     uint8_t *v = pv;
1000     qemu_put_buffer(f, v, size);
1001 }
1002
1003 const VMStateInfo vmstate_info_buffer = {
1004     .name = "buffer",
1005     .get  = get_buffer,
1006     .put  = put_buffer,
1007 };
1008
1009 /* unused buffers: space that was used for some fields that are
1010    not useful anymore */
1011
1012 static int get_unused_buffer(QEMUFile *f, void *pv, size_t size)
1013 {
1014     uint8_t buf[1024];
1015     int block_len;
1016
1017     while (size > 0) {
1018         block_len = MIN(sizeof(buf), size);
1019         size -= block_len;
1020         qemu_get_buffer(f, buf, block_len);
1021     }
1022    return 0;
1023 }
1024
1025 static void put_unused_buffer(QEMUFile *f, void *pv, size_t size)
1026 {
1027     static const uint8_t buf[1024];
1028     int block_len;
1029
1030     while (size > 0) {
1031         block_len = MIN(sizeof(buf), size);
1032         size -= block_len;
1033         qemu_put_buffer(f, buf, block_len);
1034     }
1035 }
1036
1037 const VMStateInfo vmstate_info_unused_buffer = {
1038     .name = "unused_buffer",
1039     .get  = get_unused_buffer,
1040     .put  = put_unused_buffer,
1041 };
1042
1043 typedef struct CompatEntry {
1044     char idstr[256];
1045     int instance_id;
1046 } CompatEntry;
1047
1048 typedef struct SaveStateEntry {
1049     QTAILQ_ENTRY(SaveStateEntry) entry;
1050     char idstr[256];
1051     int instance_id;
1052     int alias_id;
1053     int version_id;
1054     int section_id;
1055     SaveSetParamsHandler *set_params;
1056     SaveLiveStateHandler *save_live_state;
1057     SaveStateHandler *save_state;
1058     LoadStateHandler *load_state;
1059     const VMStateDescription *vmsd;
1060     void *opaque;
1061     CompatEntry *compat;
1062     int no_migrate;
1063 } SaveStateEntry;
1064
1065
1066 static QTAILQ_HEAD(savevm_handlers, SaveStateEntry) savevm_handlers =
1067     QTAILQ_HEAD_INITIALIZER(savevm_handlers);
1068 static int global_section_id;
1069
1070 static int calculate_new_instance_id(const char *idstr)
1071 {
1072     SaveStateEntry *se;
1073     int instance_id = 0;
1074
1075     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1076         if (strcmp(idstr, se->idstr) == 0
1077             && instance_id <= se->instance_id) {
1078             instance_id = se->instance_id + 1;
1079         }
1080     }
1081     return instance_id;
1082 }
1083
1084 static int calculate_compat_instance_id(const char *idstr)
1085 {
1086     SaveStateEntry *se;
1087     int instance_id = 0;
1088
1089     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1090         if (!se->compat)
1091             continue;
1092
1093         if (strcmp(idstr, se->compat->idstr) == 0
1094             && instance_id <= se->compat->instance_id) {
1095             instance_id = se->compat->instance_id + 1;
1096         }
1097     }
1098     return instance_id;
1099 }
1100
1101 /* TODO: Individual devices generally have very little idea about the rest
1102    of the system, so instance_id should be removed/replaced.
1103    Meanwhile pass -1 as instance_id if you do not already have a clearly
1104    distinguishing id for all instances of your device class. */
1105 int register_savevm_live(DeviceState *dev,
1106                          const char *idstr,
1107                          int instance_id,
1108                          int version_id,
1109                          SaveSetParamsHandler *set_params,
1110                          SaveLiveStateHandler *save_live_state,
1111                          SaveStateHandler *save_state,
1112                          LoadStateHandler *load_state,
1113                          void *opaque)
1114 {
1115     SaveStateEntry *se;
1116
1117     se = qemu_mallocz(sizeof(SaveStateEntry));
1118     se->version_id = version_id;
1119     se->section_id = global_section_id++;
1120     se->set_params = set_params;
1121     se->save_live_state = save_live_state;
1122     se->save_state = save_state;
1123     se->load_state = load_state;
1124     se->opaque = opaque;
1125     se->vmsd = NULL;
1126     se->no_migrate = 0;
1127
1128     if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
1129         char *id = dev->parent_bus->info->get_dev_path(dev);
1130         if (id) {
1131             pstrcpy(se->idstr, sizeof(se->idstr), id);
1132             pstrcat(se->idstr, sizeof(se->idstr), "/");
1133             qemu_free(id);
1134
1135             se->compat = qemu_mallocz(sizeof(CompatEntry));
1136             pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr);
1137             se->compat->instance_id = instance_id == -1 ?
1138                          calculate_compat_instance_id(idstr) : instance_id;
1139             instance_id = -1;
1140         }
1141     }
1142     pstrcat(se->idstr, sizeof(se->idstr), idstr);
1143
1144     if (instance_id == -1) {
1145         se->instance_id = calculate_new_instance_id(se->idstr);
1146     } else {
1147         se->instance_id = instance_id;
1148     }
1149     assert(!se->compat || se->instance_id == 0);
1150     /* add at the end of list */
1151     QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
1152     return 0;
1153 }
1154
1155 int register_savevm(DeviceState *dev,
1156                     const char *idstr,
1157                     int instance_id,
1158                     int version_id,
1159                     SaveStateHandler *save_state,
1160                     LoadStateHandler *load_state,
1161                     void *opaque)
1162 {
1163     return register_savevm_live(dev, idstr, instance_id, version_id,
1164                                 NULL, NULL, save_state, load_state, opaque);
1165 }
1166
1167 void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque)
1168 {
1169     SaveStateEntry *se, *new_se;
1170     char id[256] = "";
1171
1172     if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
1173         char *path = dev->parent_bus->info->get_dev_path(dev);
1174         if (path) {
1175             pstrcpy(id, sizeof(id), path);
1176             pstrcat(id, sizeof(id), "/");
1177             qemu_free(path);
1178         }
1179     }
1180     pstrcat(id, sizeof(id), idstr);
1181
1182     QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
1183         if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
1184             QTAILQ_REMOVE(&savevm_handlers, se, entry);
1185             if (se->compat) {
1186                 qemu_free(se->compat);
1187             }
1188             qemu_free(se);
1189         }
1190     }
1191 }
1192
1193 /* mark a device as not to be migrated, that is the device should be
1194    unplugged before migration */
1195 void register_device_unmigratable(DeviceState *dev, const char *idstr,
1196                                                             void *opaque)
1197 {
1198     SaveStateEntry *se;
1199     char id[256] = "";
1200
1201     if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
1202         char *path = dev->parent_bus->info->get_dev_path(dev);
1203         if (path) {
1204             pstrcpy(id, sizeof(id), path);
1205             pstrcat(id, sizeof(id), "/");
1206             qemu_free(path);
1207         }
1208     }
1209     pstrcat(id, sizeof(id), idstr);
1210
1211     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1212         if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
1213             se->no_migrate = 1;
1214         }
1215     }
1216 }
1217
1218 int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
1219                                    const VMStateDescription *vmsd,
1220                                    void *opaque, int alias_id,
1221                                    int required_for_version)
1222 {
1223     SaveStateEntry *se;
1224
1225     /* If this triggers, alias support can be dropped for the vmsd. */
1226     assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id);
1227
1228     se = qemu_mallocz(sizeof(SaveStateEntry));
1229     se->version_id = vmsd->version_id;
1230     se->section_id = global_section_id++;
1231     se->save_live_state = NULL;
1232     se->save_state = NULL;
1233     se->load_state = NULL;
1234     se->opaque = opaque;
1235     se->vmsd = vmsd;
1236     se->alias_id = alias_id;
1237
1238     if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
1239         char *id = dev->parent_bus->info->get_dev_path(dev);
1240         if (id) {
1241             pstrcpy(se->idstr, sizeof(se->idstr), id);
1242             pstrcat(se->idstr, sizeof(se->idstr), "/");
1243             qemu_free(id);
1244
1245             se->compat = qemu_mallocz(sizeof(CompatEntry));
1246             pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
1247             se->compat->instance_id = instance_id == -1 ?
1248                          calculate_compat_instance_id(vmsd->name) : instance_id;
1249             instance_id = -1;
1250         }
1251     }
1252     pstrcat(se->idstr, sizeof(se->idstr), vmsd->name);
1253
1254     if (instance_id == -1) {
1255         se->instance_id = calculate_new_instance_id(se->idstr);
1256     } else {
1257         se->instance_id = instance_id;
1258     }
1259     assert(!se->compat || se->instance_id == 0);
1260     /* add at the end of list */
1261     QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
1262     return 0;
1263 }
1264
1265 int vmstate_register(DeviceState *dev, int instance_id,
1266                      const VMStateDescription *vmsd, void *opaque)
1267 {
1268     return vmstate_register_with_alias_id(dev, instance_id, vmsd,
1269                                           opaque, -1, 0);
1270 }
1271
1272 void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd,
1273                         void *opaque)
1274 {
1275     SaveStateEntry *se, *new_se;
1276
1277     QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
1278         if (se->vmsd == vmsd && se->opaque == opaque) {
1279             QTAILQ_REMOVE(&savevm_handlers, se, entry);
1280             if (se->compat) {
1281                 qemu_free(se->compat);
1282             }
1283             qemu_free(se);
1284         }
1285     }
1286 }
1287
1288 static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
1289                                     void *opaque);
1290 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
1291                                    void *opaque);
1292
1293 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
1294                        void *opaque, int version_id)
1295 {
1296     VMStateField *field = vmsd->fields;
1297     int ret;
1298
1299     if (version_id > vmsd->version_id) {
1300         return -EINVAL;
1301     }
1302     if (version_id < vmsd->minimum_version_id_old) {
1303         return -EINVAL;
1304     }
1305     if  (version_id < vmsd->minimum_version_id) {
1306         return vmsd->load_state_old(f, opaque, version_id);
1307     }
1308     if (vmsd->pre_load) {
1309         int ret = vmsd->pre_load(opaque);
1310         if (ret)
1311             return ret;
1312     }
1313     while(field->name) {
1314         if ((field->field_exists &&
1315              field->field_exists(opaque, version_id)) ||
1316             (!field->field_exists &&
1317              field->version_id <= version_id)) {
1318             void *base_addr = opaque + field->offset;
1319             int i, n_elems = 1;
1320             int size = field->size;
1321
1322             if (field->flags & VMS_VBUFFER) {
1323                 size = *(int32_t *)(opaque+field->size_offset);
1324                 if (field->flags & VMS_MULTIPLY) {
1325                     size *= field->size;
1326                 }
1327             }
1328             if (field->flags & VMS_ARRAY) {
1329                 n_elems = field->num;
1330             } else if (field->flags & VMS_VARRAY_INT32) {
1331                 n_elems = *(int32_t *)(opaque+field->num_offset);
1332             } else if (field->flags & VMS_VARRAY_UINT32) {
1333                 n_elems = *(uint32_t *)(opaque+field->num_offset);
1334             } else if (field->flags & VMS_VARRAY_UINT16) {
1335                 n_elems = *(uint16_t *)(opaque+field->num_offset);
1336             } else if (field->flags & VMS_VARRAY_UINT8) {
1337                 n_elems = *(uint8_t *)(opaque+field->num_offset);
1338             }
1339             if (field->flags & VMS_POINTER) {
1340                 base_addr = *(void **)base_addr + field->start;
1341             }
1342             for (i = 0; i < n_elems; i++) {
1343                 void *addr = base_addr + size * i;
1344
1345                 if (field->flags & VMS_ARRAY_OF_POINTER) {
1346                     addr = *(void **)addr;
1347                 }
1348                 if (field->flags & VMS_STRUCT) {
1349                     ret = vmstate_load_state(f, field->vmsd, addr, field->vmsd->version_id);
1350                 } else {
1351                     ret = field->info->get(f, addr, size);
1352
1353                 }
1354                 if (ret < 0) {
1355                     return ret;
1356                 }
1357             }
1358         }
1359         field++;
1360     }
1361     ret = vmstate_subsection_load(f, vmsd, opaque);
1362     if (ret != 0) {
1363         return ret;
1364     }
1365     if (vmsd->post_load) {
1366         return vmsd->post_load(opaque, version_id);
1367     }
1368     return 0;
1369 }
1370
1371 void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
1372                         void *opaque)
1373 {
1374     VMStateField *field = vmsd->fields;
1375
1376     if (vmsd->pre_save) {
1377         vmsd->pre_save(opaque);
1378     }
1379     while(field->name) {
1380         if (!field->field_exists ||
1381             field->field_exists(opaque, vmsd->version_id)) {
1382             void *base_addr = opaque + field->offset;
1383             int i, n_elems = 1;
1384             int size = field->size;
1385
1386             if (field->flags & VMS_VBUFFER) {
1387                 size = *(int32_t *)(opaque+field->size_offset);
1388                 if (field->flags & VMS_MULTIPLY) {
1389                     size *= field->size;
1390                 }
1391             }
1392             if (field->flags & VMS_ARRAY) {
1393                 n_elems = field->num;
1394             } else if (field->flags & VMS_VARRAY_INT32) {
1395                 n_elems = *(int32_t *)(opaque+field->num_offset);
1396             } else if (field->flags & VMS_VARRAY_UINT16) {
1397                 n_elems = *(uint16_t *)(opaque+field->num_offset);
1398             } else if (field->flags & VMS_VARRAY_UINT8) {
1399                 n_elems = *(uint8_t *)(opaque+field->num_offset);
1400             }
1401             if (field->flags & VMS_POINTER) {
1402                 base_addr = *(void **)base_addr + field->start;
1403             }
1404             for (i = 0; i < n_elems; i++) {
1405                 void *addr = base_addr + size * i;
1406
1407                 if (field->flags & VMS_ARRAY_OF_POINTER) {
1408                     addr = *(void **)addr;
1409                 }
1410                 if (field->flags & VMS_STRUCT) {
1411                     vmstate_save_state(f, field->vmsd, addr);
1412                 } else {
1413                     field->info->put(f, addr, size);
1414                 }
1415             }
1416         }
1417         field++;
1418     }
1419     vmstate_subsection_save(f, vmsd, opaque);
1420 }
1421
1422 static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id)
1423 {
1424     if (!se->vmsd) {         /* Old style */
1425         return se->load_state(f, se->opaque, version_id);
1426     }
1427     return vmstate_load_state(f, se->vmsd, se->opaque, version_id);
1428 }
1429
1430 static void vmstate_save(QEMUFile *f, SaveStateEntry *se)
1431 {
1432     if (!se->vmsd) {         /* Old style */
1433         se->save_state(f, se->opaque);
1434         return;
1435     }
1436     vmstate_save_state(f,se->vmsd, se->opaque);
1437 }
1438
1439 #define QEMU_VM_FILE_MAGIC           0x5145564d
1440 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
1441 #define QEMU_VM_FILE_VERSION         0x00000003
1442
1443 #define QEMU_VM_EOF                  0x00
1444 #define QEMU_VM_SECTION_START        0x01
1445 #define QEMU_VM_SECTION_PART         0x02
1446 #define QEMU_VM_SECTION_END          0x03
1447 #define QEMU_VM_SECTION_FULL         0x04
1448 #define QEMU_VM_SUBSECTION           0x05
1449
1450 bool qemu_savevm_state_blocked(Monitor *mon)
1451 {
1452     SaveStateEntry *se;
1453
1454     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1455         if (se->no_migrate) {
1456             monitor_printf(mon, "state blocked by non-migratable device '%s'\n",
1457                            se->idstr);
1458             return true;
1459         }
1460     }
1461     return false;
1462 }
1463
1464 int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
1465                             int shared)
1466 {
1467     SaveStateEntry *se;
1468
1469     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1470         if(se->set_params == NULL) {
1471             continue;
1472         }
1473         se->set_params(blk_enable, shared, se->opaque);
1474     }
1475
1476     qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
1477     qemu_put_be32(f, QEMU_VM_FILE_VERSION);
1478
1479     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1480         int len;
1481
1482         if (se->save_live_state == NULL)
1483             continue;
1484
1485         /* Section type */
1486         qemu_put_byte(f, QEMU_VM_SECTION_START);
1487         qemu_put_be32(f, se->section_id);
1488
1489         /* ID string */
1490         len = strlen(se->idstr);
1491         qemu_put_byte(f, len);
1492         qemu_put_buffer(f, (uint8_t *)se->idstr, len);
1493
1494         qemu_put_be32(f, se->instance_id);
1495         qemu_put_be32(f, se->version_id);
1496
1497         se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
1498     }
1499
1500     if (qemu_file_has_error(f)) {
1501         qemu_savevm_state_cancel(mon, f);
1502         return -EIO;
1503     }
1504
1505     return 0;
1506 }
1507
1508 int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
1509 {
1510     SaveStateEntry *se;
1511     int ret = 1;
1512
1513     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1514         if (se->save_live_state == NULL)
1515             continue;
1516
1517         /* Section type */
1518         qemu_put_byte(f, QEMU_VM_SECTION_PART);
1519         qemu_put_be32(f, se->section_id);
1520
1521         ret = se->save_live_state(mon, f, QEMU_VM_SECTION_PART, se->opaque);
1522         if (!ret) {
1523             /* Do not proceed to the next vmstate before this one reported
1524                completion of the current stage. This serializes the migration
1525                and reduces the probability that a faster changing state is
1526                synchronized over and over again. */
1527             break;
1528         }
1529     }
1530
1531     if (ret)
1532         return 1;
1533
1534     if (qemu_file_has_error(f)) {
1535         qemu_savevm_state_cancel(mon, f);
1536         return -EIO;
1537     }
1538
1539     return 0;
1540 }
1541
1542 int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
1543 {
1544     SaveStateEntry *se;
1545
1546     cpu_synchronize_all_states();
1547
1548     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1549         if (se->save_live_state == NULL)
1550             continue;
1551
1552         /* Section type */
1553         qemu_put_byte(f, QEMU_VM_SECTION_END);
1554         qemu_put_be32(f, se->section_id);
1555
1556         se->save_live_state(mon, f, QEMU_VM_SECTION_END, se->opaque);
1557     }
1558
1559     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1560         int len;
1561
1562         if (se->save_state == NULL && se->vmsd == NULL)
1563             continue;
1564
1565         /* Section type */
1566         qemu_put_byte(f, QEMU_VM_SECTION_FULL);
1567         qemu_put_be32(f, se->section_id);
1568
1569         /* ID string */
1570         len = strlen(se->idstr);
1571         qemu_put_byte(f, len);
1572         qemu_put_buffer(f, (uint8_t *)se->idstr, len);
1573
1574         qemu_put_be32(f, se->instance_id);
1575         qemu_put_be32(f, se->version_id);
1576
1577         vmstate_save(f, se);
1578     }
1579
1580     qemu_put_byte(f, QEMU_VM_EOF);
1581
1582     if (qemu_file_has_error(f))
1583         return -EIO;
1584
1585     return 0;
1586 }
1587
1588 void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f)
1589 {
1590     SaveStateEntry *se;
1591
1592     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1593         if (se->save_live_state) {
1594             se->save_live_state(mon, f, -1, se->opaque);
1595         }
1596     }
1597 }
1598
1599 static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
1600 {
1601     int saved_vm_running;
1602     int ret;
1603
1604     saved_vm_running = vm_running;
1605     vm_stop(VMSTOP_SAVEVM);
1606
1607     if (qemu_savevm_state_blocked(mon)) {
1608         ret = -EINVAL;
1609         goto out;
1610     }
1611
1612     ret = qemu_savevm_state_begin(mon, f, 0, 0);
1613     if (ret < 0)
1614         goto out;
1615
1616     do {
1617         ret = qemu_savevm_state_iterate(mon, f);
1618         if (ret < 0)
1619             goto out;
1620     } while (ret == 0);
1621
1622     ret = qemu_savevm_state_complete(mon, f);
1623
1624 out:
1625     if (qemu_file_has_error(f))
1626         ret = -EIO;
1627
1628     if (!ret && saved_vm_running)
1629         vm_start();
1630
1631     return ret;
1632 }
1633
1634 static SaveStateEntry *find_se(const char *idstr, int instance_id)
1635 {
1636     SaveStateEntry *se;
1637
1638     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
1639         if (!strcmp(se->idstr, idstr) &&
1640             (instance_id == se->instance_id ||
1641              instance_id == se->alias_id))
1642             return se;
1643         /* Migrating from an older version? */
1644         if (strstr(se->idstr, idstr) && se->compat) {
1645             if (!strcmp(se->compat->idstr, idstr) &&
1646                 (instance_id == se->compat->instance_id ||
1647                  instance_id == se->alias_id))
1648                 return se;
1649         }
1650     }
1651     return NULL;
1652 }
1653
1654 static const VMStateDescription *vmstate_get_subsection(const VMStateSubsection *sub, char *idstr)
1655 {
1656     while(sub && sub->needed) {
1657         if (strcmp(idstr, sub->vmsd->name) == 0) {
1658             return sub->vmsd;
1659         }
1660         sub++;
1661     }
1662     return NULL;
1663 }
1664
1665 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
1666                                    void *opaque)
1667 {
1668     const VMStateSubsection *sub = vmsd->subsections;
1669
1670     if (!sub || !sub->needed) {
1671         return 0;
1672     }
1673
1674     while (qemu_peek_byte(f) == QEMU_VM_SUBSECTION) {
1675         char idstr[256];
1676         int ret;
1677         uint8_t version_id, len;
1678         const VMStateDescription *sub_vmsd;
1679
1680         qemu_get_byte(f); /* subsection */
1681         len = qemu_get_byte(f);
1682         qemu_get_buffer(f, (uint8_t *)idstr, len);
1683         idstr[len] = 0;
1684         version_id = qemu_get_be32(f);
1685
1686         sub_vmsd = vmstate_get_subsection(sub, idstr);
1687         if (sub_vmsd == NULL) {
1688             return -ENOENT;
1689         }
1690         assert(!sub_vmsd->subsections);
1691         ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
1692         if (ret) {
1693             return ret;
1694         }
1695     }
1696     return 0;
1697 }
1698
1699 static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
1700                                     void *opaque)
1701 {
1702     const VMStateSubsection *sub = vmsd->subsections;
1703
1704     while (sub && sub->needed) {
1705         if (sub->needed(opaque)) {
1706             const VMStateDescription *vmsd = sub->vmsd;
1707             uint8_t len;
1708
1709             qemu_put_byte(f, QEMU_VM_SUBSECTION);
1710             len = strlen(vmsd->name);
1711             qemu_put_byte(f, len);
1712             qemu_put_buffer(f, (uint8_t *)vmsd->name, len);
1713             qemu_put_be32(f, vmsd->version_id);
1714             assert(!vmsd->subsections);
1715             vmstate_save_state(f, vmsd, opaque);
1716         }
1717         sub++;
1718     }
1719 }
1720
1721 typedef struct LoadStateEntry {
1722     QLIST_ENTRY(LoadStateEntry) entry;
1723     SaveStateEntry *se;
1724     int section_id;
1725     int version_id;
1726 } LoadStateEntry;
1727
1728 int qemu_loadvm_state(QEMUFile *f)
1729 {
1730     QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
1731         QLIST_HEAD_INITIALIZER(loadvm_handlers);
1732     LoadStateEntry *le, *new_le;
1733     uint8_t section_type;
1734     unsigned int v;
1735     int ret;
1736
1737     if (qemu_savevm_state_blocked(default_mon)) {
1738         return -EINVAL;
1739     }
1740
1741     v = qemu_get_be32(f);
1742     if (v != QEMU_VM_FILE_MAGIC)
1743         return -EINVAL;
1744
1745     v = qemu_get_be32(f);
1746     if (v == QEMU_VM_FILE_VERSION_COMPAT) {
1747         fprintf(stderr, "SaveVM v2 format is obsolete and don't work anymore\n");
1748         return -ENOTSUP;
1749     }
1750     if (v != QEMU_VM_FILE_VERSION)
1751         return -ENOTSUP;
1752
1753     while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
1754         uint32_t instance_id, version_id, section_id;
1755         SaveStateEntry *se;
1756         char idstr[257];
1757         int len;
1758
1759         switch (section_type) {
1760         case QEMU_VM_SECTION_START:
1761         case QEMU_VM_SECTION_FULL:
1762             /* Read section start */
1763             section_id = qemu_get_be32(f);
1764             len = qemu_get_byte(f);
1765             qemu_get_buffer(f, (uint8_t *)idstr, len);
1766             idstr[len] = 0;
1767             instance_id = qemu_get_be32(f);
1768             version_id = qemu_get_be32(f);
1769
1770             /* Find savevm section */
1771             se = find_se(idstr, instance_id);
1772             if (se == NULL) {
1773                 fprintf(stderr, "Unknown savevm section or instance '%s' %d\n", idstr, instance_id);
1774                 ret = -EINVAL;
1775                 goto out;
1776             }
1777
1778             /* Validate version */
1779             if (version_id > se->version_id) {
1780                 fprintf(stderr, "savevm: unsupported version %d for '%s' v%d\n",
1781                         version_id, idstr, se->version_id);
1782                 ret = -EINVAL;
1783                 goto out;
1784             }
1785
1786             /* Add entry */
1787             le = qemu_mallocz(sizeof(*le));
1788
1789             le->se = se;
1790             le->section_id = section_id;
1791             le->version_id = version_id;
1792             QLIST_INSERT_HEAD(&loadvm_handlers, le, entry);
1793
1794             ret = vmstate_load(f, le->se, le->version_id);
1795             if (ret < 0) {
1796                 fprintf(stderr, "qemu: warning: error while loading state for instance 0x%x of device '%s'\n",
1797                         instance_id, idstr);
1798                 goto out;
1799             }
1800             break;
1801         case QEMU_VM_SECTION_PART:
1802         case QEMU_VM_SECTION_END:
1803             section_id = qemu_get_be32(f);
1804
1805             QLIST_FOREACH(le, &loadvm_handlers, entry) {
1806                 if (le->section_id == section_id) {
1807                     break;
1808                 }
1809             }
1810             if (le == NULL) {
1811                 fprintf(stderr, "Unknown savevm section %d\n", section_id);
1812                 ret = -EINVAL;
1813                 goto out;
1814             }
1815
1816             ret = vmstate_load(f, le->se, le->version_id);
1817             if (ret < 0) {
1818                 fprintf(stderr, "qemu: warning: error while loading state section id %d\n",
1819                         section_id);
1820                 goto out;
1821             }
1822             break;
1823         default:
1824             fprintf(stderr, "Unknown savevm section type %d\n", section_type);
1825             ret = -EINVAL;
1826             goto out;
1827         }
1828     }
1829
1830     cpu_synchronize_all_post_init();
1831
1832     ret = 0;
1833
1834 out:
1835     QLIST_FOREACH_SAFE(le, &loadvm_handlers, entry, new_le) {
1836         QLIST_REMOVE(le, entry);
1837         qemu_free(le);
1838     }
1839
1840     if (qemu_file_has_error(f))
1841         ret = -EIO;
1842
1843     return ret;
1844 }
1845
1846 static int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
1847                               const char *name)
1848 {
1849     QEMUSnapshotInfo *sn_tab, *sn;
1850     int nb_sns, i, ret;
1851
1852     ret = -ENOENT;
1853     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
1854     if (nb_sns < 0)
1855         return ret;
1856     for(i = 0; i < nb_sns; i++) {
1857         sn = &sn_tab[i];
1858         if (!strcmp(sn->id_str, name) || !strcmp(sn->name, name)) {
1859             *sn_info = *sn;
1860             ret = 0;
1861             break;
1862         }
1863     }
1864     qemu_free(sn_tab);
1865     return ret;
1866 }
1867
1868 /*
1869  * Deletes snapshots of a given name in all opened images.
1870  */
1871 static int del_existing_snapshots(Monitor *mon, const char *name)
1872 {
1873     BlockDriverState *bs;
1874     QEMUSnapshotInfo sn1, *snapshot = &sn1;
1875     int ret;
1876
1877     bs = NULL;
1878     while ((bs = bdrv_next(bs))) {
1879         if (bdrv_can_snapshot(bs) &&
1880             bdrv_snapshot_find(bs, snapshot, name) >= 0)
1881         {
1882             ret = bdrv_snapshot_delete(bs, name);
1883             if (ret < 0) {
1884                 monitor_printf(mon,
1885                                "Error while deleting snapshot on '%s'\n",
1886                                bdrv_get_device_name(bs));
1887                 return -1;
1888             }
1889         }
1890     }
1891
1892     return 0;
1893 }
1894
1895 void do_savevm(Monitor *mon, const QDict *qdict)
1896 {
1897     BlockDriverState *bs, *bs1;
1898     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
1899     int ret;
1900     QEMUFile *f;
1901     int saved_vm_running;
1902     uint32_t vm_state_size;
1903 #ifdef _WIN32
1904     struct _timeb tb;
1905     struct tm *ptm;
1906 #else
1907     struct timeval tv;
1908     struct tm tm;
1909 #endif
1910     const char *name = qdict_get_try_str(qdict, "name");
1911
1912     /* Verify if there is a device that doesn't support snapshots and is writable */
1913     bs = NULL;
1914     while ((bs = bdrv_next(bs))) {
1915
1916         if (bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1917             continue;
1918         }
1919
1920         if (!bdrv_can_snapshot(bs)) {
1921             monitor_printf(mon, "Device '%s' is writable but does not support snapshots.\n",
1922                                bdrv_get_device_name(bs));
1923             return;
1924         }
1925     }
1926
1927     bs = bdrv_snapshots();
1928     if (!bs) {
1929         monitor_printf(mon, "No block device can accept snapshots\n");
1930         return;
1931     }
1932
1933     saved_vm_running = vm_running;
1934     vm_stop(VMSTOP_SAVEVM);
1935
1936     memset(sn, 0, sizeof(*sn));
1937
1938     /* fill auxiliary fields */
1939 #ifdef _WIN32
1940     _ftime(&tb);
1941     sn->date_sec = tb.time;
1942     sn->date_nsec = tb.millitm * 1000000;
1943 #else
1944     gettimeofday(&tv, NULL);
1945     sn->date_sec = tv.tv_sec;
1946     sn->date_nsec = tv.tv_usec * 1000;
1947 #endif
1948     sn->vm_clock_nsec = qemu_get_clock_ns(vm_clock);
1949
1950     if (name) {
1951         ret = bdrv_snapshot_find(bs, old_sn, name);
1952         if (ret >= 0) {
1953             pstrcpy(sn->name, sizeof(sn->name), old_sn->name);
1954             pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str);
1955         } else {
1956             pstrcpy(sn->name, sizeof(sn->name), name);
1957         }
1958     } else {
1959 #ifdef _WIN32
1960         ptm = localtime(&tb.time);
1961         strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", ptm);
1962 #else
1963         /* cast below needed for OpenBSD where tv_sec is still 'long' */
1964         localtime_r((const time_t *)&tv.tv_sec, &tm);
1965         strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm);
1966 #endif
1967     }
1968
1969     /* Delete old snapshots of the same name */
1970     if (name && del_existing_snapshots(mon, name) < 0) {
1971         goto the_end;
1972     }
1973
1974     /* save the VM state */
1975     f = qemu_fopen_bdrv(bs, 1);
1976     if (!f) {
1977         monitor_printf(mon, "Could not open VM state file\n");
1978         goto the_end;
1979     }
1980     ret = qemu_savevm_state(mon, f);
1981     vm_state_size = qemu_ftell(f);
1982     qemu_fclose(f);
1983     if (ret < 0) {
1984         monitor_printf(mon, "Error %d while writing VM\n", ret);
1985         goto the_end;
1986     }
1987
1988     /* create the snapshots */
1989
1990     bs1 = NULL;
1991     while ((bs1 = bdrv_next(bs1))) {
1992         if (bdrv_can_snapshot(bs1)) {
1993             /* Write VM state size only to the image that contains the state */
1994             sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
1995             ret = bdrv_snapshot_create(bs1, sn);
1996             if (ret < 0) {
1997                 monitor_printf(mon, "Error while creating snapshot on '%s'\n",
1998                                bdrv_get_device_name(bs1));
1999             }
2000         }
2001     }
2002
2003  the_end:
2004     if (saved_vm_running)
2005         vm_start();
2006 }
2007
2008 int load_vmstate(const char *name)
2009 {
2010     BlockDriverState *bs, *bs_vm_state;
2011     QEMUSnapshotInfo sn;
2012     QEMUFile *f;
2013     int ret;
2014
2015     bs_vm_state = bdrv_snapshots();
2016     if (!bs_vm_state) {
2017         error_report("No block device supports snapshots");
2018         return -ENOTSUP;
2019     }
2020
2021     /* Don't even try to load empty VM states */
2022     ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
2023     if (ret < 0) {
2024         return ret;
2025     } else if (sn.vm_state_size == 0) {
2026         error_report("This is a disk-only snapshot. Revert to it offline "
2027             "using qemu-img.");
2028         return -EINVAL;
2029     }
2030
2031     /* Verify if there is any device that doesn't support snapshots and is
2032     writable and check if the requested snapshot is available too. */
2033     bs = NULL;
2034     while ((bs = bdrv_next(bs))) {
2035
2036         if (bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
2037             continue;
2038         }
2039
2040         if (!bdrv_can_snapshot(bs)) {
2041             error_report("Device '%s' is writable but does not support snapshots.",
2042                                bdrv_get_device_name(bs));
2043             return -ENOTSUP;
2044         }
2045
2046         ret = bdrv_snapshot_find(bs, &sn, name);
2047         if (ret < 0) {
2048             error_report("Device '%s' does not have the requested snapshot '%s'",
2049                            bdrv_get_device_name(bs), name);
2050             return ret;
2051         }
2052     }
2053
2054     /* Flush all IO requests so they don't interfere with the new state.  */
2055     qemu_aio_flush();
2056
2057     bs = NULL;
2058     while ((bs = bdrv_next(bs))) {
2059         if (bdrv_can_snapshot(bs)) {
2060             ret = bdrv_snapshot_goto(bs, name);
2061             if (ret < 0) {
2062                 error_report("Error %d while activating snapshot '%s' on '%s'",
2063                              ret, name, bdrv_get_device_name(bs));
2064                 return ret;
2065             }
2066         }
2067     }
2068
2069     /* restore the VM state */
2070     f = qemu_fopen_bdrv(bs_vm_state, 0);
2071     if (!f) {
2072         error_report("Could not open VM state file");
2073         return -EINVAL;
2074     }
2075
2076     qemu_system_reset(VMRESET_SILENT);
2077     ret = qemu_loadvm_state(f);
2078
2079     qemu_fclose(f);
2080     if (ret < 0) {
2081         error_report("Error %d while loading VM state", ret);
2082         return ret;
2083     }
2084
2085     return 0;
2086 }
2087
2088 void do_delvm(Monitor *mon, const QDict *qdict)
2089 {
2090     BlockDriverState *bs, *bs1;
2091     int ret;
2092     const char *name = qdict_get_str(qdict, "name");
2093
2094     bs = bdrv_snapshots();
2095     if (!bs) {
2096         monitor_printf(mon, "No block device supports snapshots\n");
2097         return;
2098     }
2099
2100     bs1 = NULL;
2101     while ((bs1 = bdrv_next(bs1))) {
2102         if (bdrv_can_snapshot(bs1)) {
2103             ret = bdrv_snapshot_delete(bs1, name);
2104             if (ret < 0) {
2105                 if (ret == -ENOTSUP)
2106                     monitor_printf(mon,
2107                                    "Snapshots not supported on device '%s'\n",
2108                                    bdrv_get_device_name(bs1));
2109                 else
2110                     monitor_printf(mon, "Error %d while deleting snapshot on "
2111                                    "'%s'\n", ret, bdrv_get_device_name(bs1));
2112             }
2113         }
2114     }
2115 }
2116
2117 void do_info_snapshots(Monitor *mon)
2118 {
2119     BlockDriverState *bs, *bs1;
2120     QEMUSnapshotInfo *sn_tab, *sn, s, *sn_info = &s;
2121     int nb_sns, i, ret, available;
2122     int total;
2123     int *available_snapshots;
2124     char buf[256];
2125
2126     bs = bdrv_snapshots();
2127     if (!bs) {
2128         monitor_printf(mon, "No available block device supports snapshots\n");
2129         return;
2130     }
2131
2132     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
2133     if (nb_sns < 0) {
2134         monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns);
2135         return;
2136     }
2137
2138     if (nb_sns == 0) {
2139         monitor_printf(mon, "There is no snapshot available.\n");
2140         return;
2141     }
2142
2143     available_snapshots = qemu_mallocz(sizeof(int) * nb_sns);
2144     total = 0;
2145     for (i = 0; i < nb_sns; i++) {
2146         sn = &sn_tab[i];
2147         available = 1;
2148         bs1 = NULL;
2149
2150         while ((bs1 = bdrv_next(bs1))) {
2151             if (bdrv_can_snapshot(bs1) && bs1 != bs) {
2152                 ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str);
2153                 if (ret < 0) {
2154                     available = 0;
2155                     break;
2156                 }
2157             }
2158         }
2159
2160         if (available) {
2161             available_snapshots[total] = i;
2162             total++;
2163         }
2164     }
2165
2166     if (total > 0) {
2167         monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
2168         for (i = 0; i < total; i++) {
2169             sn = &sn_tab[available_snapshots[i]];
2170             monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
2171         }
2172     } else {
2173         monitor_printf(mon, "There is no suitable snapshot available\n");
2174     }
2175
2176     qemu_free(sn_tab);
2177     qemu_free(available_snapshots);
2178
2179 }