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