blockdev.c

   1 /*
   2  * QEMU host block devices
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or
   7  * later.  See the COPYING file in the top-level directory.
   8  */
   9
  10 #include "block.h"
  11 #include "blockdev.h"
  12 #include "monitor.h"
  13 #include "qerror.h"
  14 #include "qemu-option.h"
  15 #include "qemu-config.h"
  16 #include "sysemu.h"
  17 #include "hw/qdev.h"
  18 #include "block_int.h"
  19
  20 DriveInfo *extboot_drive = NULL;
  21
  22 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
  23
  24 static const char *const if_name[IF_COUNT] = {
  25     [IF_NONE] = "none",
  26     [IF_IDE] = "ide",
  27     [IF_SCSI] = "scsi",
  28     [IF_FLOPPY] = "floppy",
  29     [IF_PFLASH] = "pflash",
  30     [IF_MTD] = "mtd",
  31     [IF_SD] = "sd",
  32     [IF_VIRTIO] = "virtio",
  33     [IF_XEN] = "xen",
  34 };
  35
  36 static const int if_max_devs[IF_COUNT] = {
  37     /*
  38      * Do not change these numbers!  They govern how drive option
  39      * index maps to unit and bus.  That mapping is ABI.
  40      *
  41      * All controllers used to imlement if=T drives need to support
  42      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
  43      * Otherwise, some index values map to "impossible" bus, unit
  44      * values.
  45      *
  46      * For instance, if you change [IF_SCSI] to 255, -drive
  47      * if=scsi,index=12 no longer means bus=1,unit=5, but
  48      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
  49      * the drive can't be set up.  Regression.
  50      */
  51     [IF_IDE] = 2,
  52     [IF_SCSI] = 7,
  53 };
  54
  55 /*
  56  * We automatically delete the drive when a device using it gets
  57  * unplugged.  Questionable feature, but we can't just drop it.
  58  * Device models call blockdev_mark_auto_del() to schedule the
  59  * automatic deletion, and generic qdev code calls blockdev_auto_del()
  60  * when deletion is actually safe.
  61  */
  62 void blockdev_mark_auto_del(BlockDriverState *bs)
  63 {
  64     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  65
  66     if (dinfo) {
  67         dinfo->auto_del = 1;
  68     }
  69 }
  70
  71 void blockdev_auto_del(BlockDriverState *bs)
  72 {
  73     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  74
  75     if (dinfo && dinfo->auto_del) {
  76         drive_put_ref(dinfo);
  77     }
  78 }
  79
  80 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
  81 {
  82     int max_devs = if_max_devs[type];
  83     return max_devs ? index / max_devs : 0;
  84 }
  85
  86 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
  87 {
  88     int max_devs = if_max_devs[type];
  89     return max_devs ? index % max_devs : index;
  90 }
  91
  92 QemuOpts *drive_def(const char *optstr)
  93 {
  94     return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
  95 }
  96
  97 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
  98                     const char *optstr)
  99 {
 100     QemuOpts *opts;
 101     char buf[32];
 102
 103     opts = drive_def(optstr);
 104     if (!opts) {
 105         return NULL;
 106     }
 107     if (type != IF_DEFAULT) {
 108         qemu_opt_set(opts, "if", if_name[type]);
 109     }
 110     if (index >= 0) {
 111         snprintf(buf, sizeof(buf), "%d", index);
 112         qemu_opt_set(opts, "index", buf);
 113     }
 114     if (file)
 115         qemu_opt_set(opts, "file", file);
 116     return opts;
 117 }
 118
 119 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
 120 {
 121     DriveInfo *dinfo;
 122
 123     /* seek interface, bus and unit */
 124
 125     QTAILQ_FOREACH(dinfo, &drives, next) {
 126         if (dinfo->type == type &&
 127             dinfo->bus == bus &&
 128             dinfo->unit == unit)
 129             return dinfo;
 130     }
 131
 132     return NULL;
 133 }
 134
 135 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
 136 {
 137     return drive_get(type,
 138                      drive_index_to_bus_id(type, index),
 139                      drive_index_to_unit_id(type, index));
 140 }
 141
 142 int drive_get_max_bus(BlockInterfaceType type)
 143 {
 144     int max_bus;
 145     DriveInfo *dinfo;
 146
 147     max_bus = -1;
 148     QTAILQ_FOREACH(dinfo, &drives, next) {
 149         if(dinfo->type == type &&
 150            dinfo->bus > max_bus)
 151             max_bus = dinfo->bus;
 152     }
 153     return max_bus;
 154 }
 155
 156 /* Get a block device.  This should only be used for single-drive devices
 157    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
 158    appropriate bus.  */
 159 DriveInfo *drive_get_next(BlockInterfaceType type)
 160 {
 161     static int next_block_unit[IF_COUNT];
 162
 163     return drive_get(type, 0, next_block_unit[type]++);
 164 }
 165
 166 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
 167 {
 168     DriveInfo *dinfo;
 169
 170     QTAILQ_FOREACH(dinfo, &drives, next) {
 171         if (dinfo->bdrv == bs) {
 172             return dinfo;
 173         }
 174     }
 175     return NULL;
 176 }
 177
 178 static void bdrv_format_print(void *opaque, const char *name)
 179 {
 180     error_printf(" %s", name);
 181 }
 182
 183 static void drive_uninit(DriveInfo *dinfo)
 184 {
 185     qemu_opts_del(dinfo->opts);
 186     bdrv_delete(dinfo->bdrv);
 187     g_free(dinfo->id);
 188     QTAILQ_REMOVE(&drives, dinfo, next);
 189     g_free(dinfo);
 190 }
 191
 192 void drive_put_ref(DriveInfo *dinfo)
 193 {
 194     assert(dinfo->refcount);
 195     if (--dinfo->refcount == 0) {
 196         drive_uninit(dinfo);
 197     }
 198 }
 199
 200 void drive_get_ref(DriveInfo *dinfo)
 201 {
 202     dinfo->refcount++;
 203 }
 204
 205 static int parse_block_error_action(const char *buf, int is_read)
 206 {
 207     if (!strcmp(buf, "ignore")) {
 208         return BLOCK_ERR_IGNORE;
 209     } else if (!is_read && !strcmp(buf, "enospc")) {
 210         return BLOCK_ERR_STOP_ENOSPC;
 211     } else if (!strcmp(buf, "stop")) {
 212         return BLOCK_ERR_STOP_ANY;
 213     } else if (!strcmp(buf, "report")) {
 214         return BLOCK_ERR_REPORT;
 215     } else {
 216         error_report("'%s' invalid %s error action",
 217                      buf, is_read ? "read" : "write");
 218         return -1;
 219     }
 220 }
 221
 222 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
 223 {
 224     const char *buf;
 225     const char *file = NULL;
 226     char devname[128];
 227     const char *serial;
 228     const char *mediastr = "";
 229     BlockInterfaceType type;
 230     enum { MEDIA_DISK, MEDIA_CDROM } media;
 231     int bus_id, unit_id;
 232     int cyls, heads, secs, translation;
 233     BlockDriver *drv = NULL;
 234     int max_devs;
 235     int index;
 236     int ro = 0;
 237     int bdrv_flags = 0;
 238     int on_read_error, on_write_error;
 239     const char *devaddr;
 240     DriveInfo *dinfo;
 241     int is_extboot = 0;
 242     int snapshot = 0;
 243     int ret;
 244
 245     translation = BIOS_ATA_TRANSLATION_AUTO;
 246     media = MEDIA_DISK;
 247
 248     /* extract parameters */
 249     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 250     unit_id = qemu_opt_get_number(opts, "unit", -1);
 251     index   = qemu_opt_get_number(opts, "index", -1);
 252
 253     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 254     heads = qemu_opt_get_number(opts, "heads", 0);
 255     secs  = qemu_opt_get_number(opts, "secs", 0);
 256
 257     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 258     ro = qemu_opt_get_bool(opts, "readonly", 0);
 259
 260     file = qemu_opt_get(opts, "file");
 261     serial = qemu_opt_get(opts, "serial");
 262
 263     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 264         pstrcpy(devname, sizeof(devname), buf);
 265         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
 266             ;
 267         if (type == IF_COUNT) {
 268             error_report("unsupported bus type '%s'", buf);
 269             return NULL;
 270         }
 271     } else {
 272         type = default_to_scsi ? IF_SCSI : IF_IDE;
 273         pstrcpy(devname, sizeof(devname), if_name[type]);
 274     }
 275
 276     max_devs = if_max_devs[type];
 277
 278     if (cyls || heads || secs) {
 279         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 280             error_report("invalid physical cyls number");
 281             return NULL;
 282         }
 283         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 284             error_report("invalid physical heads number");
 285             return NULL;
 286         }
 287         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 288             error_report("invalid physical secs number");
 289             return NULL;
 290         }
 291     }
 292
 293     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 294         if (!cyls) {
 295             error_report("'%s' trans must be used with cyls, heads and secs",
 296                          buf);
 297             return NULL;
 298         }
 299         if (!strcmp(buf, "none"))
 300             translation = BIOS_ATA_TRANSLATION_NONE;
 301         else if (!strcmp(buf, "lba"))
 302             translation = BIOS_ATA_TRANSLATION_LBA;
 303         else if (!strcmp(buf, "auto"))
 304             translation = BIOS_ATA_TRANSLATION_AUTO;
 305         else {
 306             error_report("'%s' invalid translation type", buf);
 307             return NULL;
 308         }
 309     }
 310
 311     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 312         if (!strcmp(buf, "disk")) {
 313             media = MEDIA_DISK;
 314         } else if (!strcmp(buf, "cdrom")) {
 315             if (cyls || secs || heads) {
 316                 error_report("CHS can't be set with media=%s", buf);
 317                 return NULL;
 318             }
 319             media = MEDIA_CDROM;
 320         } else {
 321             error_report("'%s' invalid media", buf);
 322             return NULL;
 323         }
 324     }
 325
 326     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 327         if (!strcmp(buf, "off") || !strcmp(buf, "none")) {
 328             bdrv_flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
 329         } else if (!strcmp(buf, "writeback")) {
 330             bdrv_flags |= BDRV_O_CACHE_WB;
 331         } else if (!strcmp(buf, "unsafe")) {
 332             bdrv_flags |= BDRV_O_CACHE_WB;
 333             bdrv_flags |= BDRV_O_NO_FLUSH;
 334         } else if (!strcmp(buf, "writethrough")) {
 335             /* this is the default */
 336         } else {
 337            error_report("invalid cache option");
 338            return NULL;
 339         }
 340     }
 341
 342 #ifdef CONFIG_LINUX_AIO
 343     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 344         if (!strcmp(buf, "native")) {
 345             bdrv_flags |= BDRV_O_NATIVE_AIO;
 346         } else if (!strcmp(buf, "threads")) {
 347             /* this is the default */
 348         } else {
 349            error_report("invalid aio option");
 350            return NULL;
 351         }
 352     }
 353 #endif
 354
 355     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 356        if (strcmp(buf, "?") == 0) {
 357            error_printf("Supported formats:");
 358            bdrv_iterate_format(bdrv_format_print, NULL);
 359            error_printf("\n");
 360            return NULL;
 361         }
 362         drv = bdrv_find_whitelisted_format(buf);
 363         if (!drv) {
 364             error_report("'%s' invalid format", buf);
 365             return NULL;
 366         }
 367     }
 368
 369     is_extboot = qemu_opt_get_bool(opts, "boot", 0);
 370     if (is_extboot && extboot_drive) {
 371         fprintf(stderr, "qemu: two bootable drives specified\n");
 372         return NULL;
 373     }
 374
 375     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 376     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 377         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 378             error_report("werror is not supported by this bus type");
 379             return NULL;
 380         }
 381
 382         on_write_error = parse_block_error_action(buf, 0);
 383         if (on_write_error < 0) {
 384             return NULL;
 385         }
 386     }
 387
 388     on_read_error = BLOCK_ERR_REPORT;
 389     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 390         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 391             error_report("rerror is not supported by this bus type");
 392             return NULL;
 393         }
 394
 395         on_read_error = parse_block_error_action(buf, 1);
 396         if (on_read_error < 0) {
 397             return NULL;
 398         }
 399     }
 400
 401     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 402         if (type != IF_VIRTIO) {
 403             error_report("addr is not supported by this bus type");
 404             return NULL;
 405         }
 406     }
 407
 408     /* compute bus and unit according index */
 409
 410     if (index != -1) {
 411         if (bus_id != 0 || unit_id != -1) {
 412             error_report("index cannot be used with bus and unit");
 413             return NULL;
 414         }
 415         bus_id = drive_index_to_bus_id(type, index);
 416         unit_id = drive_index_to_unit_id(type, index);
 417     }
 418
 419     /* if user doesn't specify a unit_id,
 420      * try to find the first free
 421      */
 422
 423     if (unit_id == -1) {
 424        unit_id = 0;
 425        while (drive_get(type, bus_id, unit_id) != NULL) {
 426            unit_id++;
 427            if (max_devs && unit_id >= max_devs) {
 428                unit_id -= max_devs;
 429                bus_id++;
 430            }
 431        }
 432     }
 433
 434     /* check unit id */
 435
 436     if (max_devs && unit_id >= max_devs) {
 437         error_report("unit %d too big (max is %d)",
 438                      unit_id, max_devs - 1);
 439         return NULL;
 440     }
 441
 442     /*
 443      * catch multiple definitions
 444      */
 445
 446     if (drive_get(type, bus_id, unit_id) != NULL) {
 447         error_report("drive with bus=%d, unit=%d (index=%d) exists",
 448                      bus_id, unit_id, index);
 449         return NULL;
 450     }
 451
 452     /* init */
 453
 454     dinfo = g_malloc0(sizeof(*dinfo));
 455     if ((buf = qemu_opts_id(opts)) != NULL) {
 456         dinfo->id = g_strdup(buf);
 457     } else {
 458         /* no id supplied -> create one */
 459         dinfo->id = g_malloc0(32);
 460         if (type == IF_IDE || type == IF_SCSI)
 461             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 462         if (max_devs)
 463             snprintf(dinfo->id, 32, "%s%i%s%i",
 464                      devname, bus_id, mediastr, unit_id);
 465         else
 466             snprintf(dinfo->id, 32, "%s%s%i",
 467                      devname, mediastr, unit_id);
 468     }
 469     dinfo->bdrv = bdrv_new(dinfo->id);
 470     dinfo->devaddr = devaddr;
 471     dinfo->type = type;
 472     dinfo->bus = bus_id;
 473     dinfo->unit = unit_id;
 474     dinfo->opts = opts;
 475     dinfo->refcount = 1;
 476     if (serial)
 477         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 478     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 479
 480     if (is_extboot) {
 481         extboot_drive = dinfo;
 482     }
 483
 484     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 485
 486     switch(type) {
 487     case IF_IDE:
 488     case IF_SCSI:
 489     case IF_XEN:
 490     case IF_NONE:
 491         switch(media) {
 492         case MEDIA_DISK:
 493             if (cyls != 0) {
 494                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 495                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 496             }
 497             break;
 498         case MEDIA_CDROM:
 499             bdrv_set_removable(dinfo->bdrv, 1);
 500             dinfo->media_cd = 1;
 501             break;
 502         }
 503         break;
 504     case IF_SD:
 505         /* FIXME: This isn't really a floppy, but it's a reasonable
 506            approximation.  */
 507     case IF_FLOPPY:
 508         bdrv_set_removable(dinfo->bdrv, 1);
 509         break;
 510     case IF_PFLASH:
 511     case IF_MTD:
 512         break;
 513     case IF_VIRTIO:
 514         /* add virtio block device */
 515         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 516         qemu_opt_set(opts, "driver", "virtio-blk");
 517         qemu_opt_set(opts, "drive", dinfo->id);
 518         if (devaddr)
 519             qemu_opt_set(opts, "addr", devaddr);
 520         break;
 521     default:
 522         abort();
 523     }
 524     if (!file || !*file) {
 525         return dinfo;
 526     }
 527     if (snapshot) {
 528         /* always use cache=unsafe with snapshot */
 529         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 530         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 531     }
 532
 533     if (media == MEDIA_CDROM) {
 534         /* CDROM is fine for any interface, don't check.  */
 535         ro = 1;
 536     } else if (ro == 1) {
 537         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 538             error_report("readonly not supported by this bus type");
 539             goto err;
 540         }
 541     }
 542
 543     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 544
 545     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 546     if (ret < 0) {
 547         error_report("could not open disk image %s: %s",
 548                      file, strerror(-ret));
 549         goto err;
 550     }
 551
 552     if (bdrv_key_required(dinfo->bdrv))
 553         autostart = 0;
 554     return dinfo;
 555
 556 err:
 557     bdrv_delete(dinfo->bdrv);
 558     g_free(dinfo->id);
 559     QTAILQ_REMOVE(&drives, dinfo, next);
 560     g_free(dinfo);
 561     return NULL;
 562 }
 563
 564 void do_commit(Monitor *mon, const QDict *qdict)
 565 {
 566     const char *device = qdict_get_str(qdict, "device");
 567     BlockDriverState *bs;
 568
 569     if (!strcmp(device, "all")) {
 570         bdrv_commit_all();
 571     } else {
 572         bs = bdrv_find(device);
 573         if (!bs) {
 574             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 575             return;
 576         }
 577         bdrv_commit(bs);
 578     }
 579 }
 580
 581 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
 582 {
 583     const char *device = qdict_get_str(qdict, "device");
 584     const char *filename = qdict_get_try_str(qdict, "snapshot-file");
 585     const char *format = qdict_get_try_str(qdict, "format");
 586     BlockDriverState *bs;
 587     BlockDriver *drv, *old_drv, *proto_drv;
 588     int ret = 0;
 589     int flags;
 590     char old_filename[1024];
 591
 592     if (!filename) {
 593         qerror_report(QERR_MISSING_PARAMETER, "snapshot-file");
 594         ret = -1;
 595         goto out;
 596     }
 597
 598     bs = bdrv_find(device);
 599     if (!bs) {
 600         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 601         ret = -1;
 602         goto out;
 603     }
 604
 605     pstrcpy(old_filename, sizeof(old_filename), bs->filename);
 606
 607     old_drv = bs->drv;
 608     flags = bs->open_flags;
 609
 610     if (!format) {
 611         format = "qcow2";
 612     }
 613
 614     drv = bdrv_find_format(format);
 615     if (!drv) {
 616         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 617         ret = -1;
 618         goto out;
 619     }
 620
 621     proto_drv = bdrv_find_protocol(filename);
 622     if (!proto_drv) {
 623         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 624         ret = -1;
 625         goto out;
 626     }
 627
 628     ret = bdrv_img_create(filename, format, bs->filename,
 629                           bs->drv->format_name, NULL, -1, flags);
 630     if (ret) {
 631         goto out;
 632     }
 633
 634     qemu_aio_flush();
 635     bdrv_flush(bs);
 636
 637     bdrv_close(bs);
 638     ret = bdrv_open(bs, filename, flags, drv);
 639     /*
 640      * If reopening the image file we just created fails, fall back
 641      * and try to re-open the original image. If that fails too, we
 642      * are in serious trouble.
 643      */
 644     if (ret != 0) {
 645         ret = bdrv_open(bs, old_filename, flags, old_drv);
 646         if (ret != 0) {
 647             qerror_report(QERR_OPEN_FILE_FAILED, old_filename);
 648         } else {
 649             qerror_report(QERR_OPEN_FILE_FAILED, filename);
 650         }
 651     }
 652 out:
 653     if (ret) {
 654         ret = -1;
 655     }
 656
 657     return ret;
 658 }
 659
 660 static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
 661 {
 662     if (!bdrv_is_removable(bs)) {
 663         qerror_report(QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
 664         return -1;
 665     }
 666     if (!force && bdrv_is_locked(bs)) {
 667         qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 668         return -1;
 669     }
 670     bdrv_close(bs);
 671     return 0;
 672 }
 673
 674 int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
 675 {
 676     BlockDriverState *bs;
 677     int force = qdict_get_try_bool(qdict, "force", 0);
 678     const char *filename = qdict_get_str(qdict, "device");
 679
 680     bs = bdrv_find(filename);
 681     if (!bs) {
 682         qerror_report(QERR_DEVICE_NOT_FOUND, filename);
 683         return -1;
 684     }
 685     return eject_device(mon, bs, force);
 686 }
 687
 688 int do_block_set_passwd(Monitor *mon, const QDict *qdict,
 689                         QObject **ret_data)
 690 {
 691     BlockDriverState *bs;
 692     int err;
 693
 694     bs = bdrv_find(qdict_get_str(qdict, "device"));
 695     if (!bs) {
 696         qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
 697         return -1;
 698     }
 699
 700     err = bdrv_set_key(bs, qdict_get_str(qdict, "password"));
 701     if (err == -EINVAL) {
 702         qerror_report(QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 703         return -1;
 704     } else if (err < 0) {
 705         qerror_report(QERR_INVALID_PASSWORD);
 706         return -1;
 707     }
 708
 709     return 0;
 710 }
 711
 712 int do_change_block(Monitor *mon, const char *device,
 713                     const char *filename, const char *fmt)
 714 {
 715     BlockDriverState *bs;
 716     BlockDriver *drv = NULL;
 717     int bdrv_flags;
 718
 719     bs = bdrv_find(device);
 720     if (!bs) {
 721         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 722         return -1;
 723     }
 724     if (fmt) {
 725         drv = bdrv_find_whitelisted_format(fmt);
 726         if (!drv) {
 727             qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
 728             return -1;
 729         }
 730     }
 731     if (eject_device(mon, bs, 0) < 0) {
 732         return -1;
 733     }
 734     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 735     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 736     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 737         qerror_report(QERR_OPEN_FILE_FAILED, filename);
 738         return -1;
 739     }
 740     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
 741 }
 742
 743 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 744 {
 745     const char *id = qdict_get_str(qdict, "id");
 746     BlockDriverState *bs;
 747
 748     bs = bdrv_find(id);
 749     if (!bs) {
 750         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 751         return -1;
 752     }
 753     if (bdrv_in_use(bs)) {
 754         qerror_report(QERR_DEVICE_IN_USE, id);
 755         return -1;
 756     }
 757
 758     /* quiesce block driver; prevent further io */
 759     qemu_aio_flush();
 760     bdrv_flush(bs);
 761     bdrv_close(bs);
 762
 763     /* if we have a device associated with this BlockDriverState (bs->peer)
 764      * then we need to make the drive anonymous until the device
 765      * can be removed.  If this is a drive with no device backing
 766      * then we can just get rid of the block driver state right here.
 767      */
 768     if (bs->peer) {
 769         bdrv_make_anon(bs);
 770     } else {
 771         drive_uninit(drive_get_by_blockdev(bs));
 772     }
 773
 774     return 0;
 775 }
 776
 777 /*
 778  * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
 779  * existing QERR_ macro mess is cleaned up.  A good example for better
 780  * error reports can be found in the qemu-img resize code.
 781  */
 782 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
 783 {
 784     const char *device = qdict_get_str(qdict, "device");
 785     int64_t size = qdict_get_int(qdict, "size");
 786     BlockDriverState *bs;
 787
 788     bs = bdrv_find(device);
 789     if (!bs) {
 790         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 791         return -1;
 792     }
 793
 794     if (size < 0) {
 795         qerror_report(QERR_UNDEFINED_ERROR);
 796         return -1;
 797     }
 798
 799     if (bdrv_truncate(bs, size)) {
 800         qerror_report(QERR_UNDEFINED_ERROR);
 801         return -1;
 802     }
 803
 804     return 0;
 805 }