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 "qemu-objects.h"
  17 #include "sysemu.h"
  18 #include "block_int.h"
  19 #include "qmp-commands.h"
  20 #include "trace.h"
  21 #include "arch_init.h"
  22
  23 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
  24
  25 static const char *const if_name[IF_COUNT] = {
  26     [IF_NONE] = "none",
  27     [IF_IDE] = "ide",
  28     [IF_SCSI] = "scsi",
  29     [IF_FLOPPY] = "floppy",
  30     [IF_PFLASH] = "pflash",
  31     [IF_MTD] = "mtd",
  32     [IF_SD] = "sd",
  33     [IF_VIRTIO] = "virtio",
  34     [IF_XEN] = "xen",
  35 };
  36
  37 static const int if_max_devs[IF_COUNT] = {
  38     /*
  39      * Do not change these numbers!  They govern how drive option
  40      * index maps to unit and bus.  That mapping is ABI.
  41      *
  42      * All controllers used to imlement if=T drives need to support
  43      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
  44      * Otherwise, some index values map to "impossible" bus, unit
  45      * values.
  46      *
  47      * For instance, if you change [IF_SCSI] to 255, -drive
  48      * if=scsi,index=12 no longer means bus=1,unit=5, but
  49      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
  50      * the drive can't be set up.  Regression.
  51      */
  52     [IF_IDE] = 2,
  53     [IF_SCSI] = 7,
  54 };
  55
  56 /*
  57  * We automatically delete the drive when a device using it gets
  58  * unplugged.  Questionable feature, but we can't just drop it.
  59  * Device models call blockdev_mark_auto_del() to schedule the
  60  * automatic deletion, and generic qdev code calls blockdev_auto_del()
  61  * when deletion is actually safe.
  62  */
  63 void blockdev_mark_auto_del(BlockDriverState *bs)
  64 {
  65     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  66
  67     if (dinfo) {
  68         dinfo->auto_del = 1;
  69     }
  70 }
  71
  72 void blockdev_auto_del(BlockDriverState *bs)
  73 {
  74     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  75
  76     if (dinfo && dinfo->auto_del) {
  77         drive_put_ref(dinfo);
  78     }
  79 }
  80
  81 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
  82 {
  83     int max_devs = if_max_devs[type];
  84     return max_devs ? index / max_devs : 0;
  85 }
  86
  87 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
  88 {
  89     int max_devs = if_max_devs[type];
  90     return max_devs ? index % max_devs : index;
  91 }
  92
  93 QemuOpts *drive_def(const char *optstr)
  94 {
  95     return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
  96 }
  97
  98 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
  99                     const char *optstr)
 100 {
 101     QemuOpts *opts;
 102     char buf[32];
 103
 104     opts = drive_def(optstr);
 105     if (!opts) {
 106         return NULL;
 107     }
 108     if (type != IF_DEFAULT) {
 109         qemu_opt_set(opts, "if", if_name[type]);
 110     }
 111     if (index >= 0) {
 112         snprintf(buf, sizeof(buf), "%d", index);
 113         qemu_opt_set(opts, "index", buf);
 114     }
 115     if (file)
 116         qemu_opt_set(opts, "file", file);
 117     return opts;
 118 }
 119
 120 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
 121 {
 122     DriveInfo *dinfo;
 123
 124     /* seek interface, bus and unit */
 125
 126     QTAILQ_FOREACH(dinfo, &drives, next) {
 127         if (dinfo->type == type &&
 128             dinfo->bus == bus &&
 129             dinfo->unit == unit)
 130             return dinfo;
 131     }
 132
 133     return NULL;
 134 }
 135
 136 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
 137 {
 138     return drive_get(type,
 139                      drive_index_to_bus_id(type, index),
 140                      drive_index_to_unit_id(type, index));
 141 }
 142
 143 int drive_get_max_bus(BlockInterfaceType type)
 144 {
 145     int max_bus;
 146     DriveInfo *dinfo;
 147
 148     max_bus = -1;
 149     QTAILQ_FOREACH(dinfo, &drives, next) {
 150         if(dinfo->type == type &&
 151            dinfo->bus > max_bus)
 152             max_bus = dinfo->bus;
 153     }
 154     return max_bus;
 155 }
 156
 157 /* Get a block device.  This should only be used for single-drive devices
 158    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
 159    appropriate bus.  */
 160 DriveInfo *drive_get_next(BlockInterfaceType type)
 161 {
 162     static int next_block_unit[IF_COUNT];
 163
 164     return drive_get(type, 0, next_block_unit[type]++);
 165 }
 166
 167 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
 168 {
 169     DriveInfo *dinfo;
 170
 171     QTAILQ_FOREACH(dinfo, &drives, next) {
 172         if (dinfo->bdrv == bs) {
 173             return dinfo;
 174         }
 175     }
 176     return NULL;
 177 }
 178
 179 static void bdrv_format_print(void *opaque, const char *name)
 180 {
 181     error_printf(" %s", name);
 182 }
 183
 184 static void drive_uninit(DriveInfo *dinfo)
 185 {
 186     qemu_opts_del(dinfo->opts);
 187     bdrv_delete(dinfo->bdrv);
 188     g_free(dinfo->id);
 189     QTAILQ_REMOVE(&drives, dinfo, next);
 190     g_free(dinfo);
 191 }
 192
 193 void drive_put_ref(DriveInfo *dinfo)
 194 {
 195     assert(dinfo->refcount);
 196     if (--dinfo->refcount == 0) {
 197         drive_uninit(dinfo);
 198     }
 199 }
 200
 201 void drive_get_ref(DriveInfo *dinfo)
 202 {
 203     dinfo->refcount++;
 204 }
 205
 206 typedef struct {
 207     QEMUBH *bh;
 208     DriveInfo *dinfo;
 209 } DrivePutRefBH;
 210
 211 static void drive_put_ref_bh(void *opaque)
 212 {
 213     DrivePutRefBH *s = opaque;
 214
 215     drive_put_ref(s->dinfo);
 216     qemu_bh_delete(s->bh);
 217     g_free(s);
 218 }
 219
 220 /*
 221  * Release a drive reference in a BH
 222  *
 223  * It is not possible to use drive_put_ref() from a callback function when the
 224  * callers still need the drive.  In such cases we schedule a BH to release the
 225  * reference.
 226  */
 227 static void drive_put_ref_bh_schedule(DriveInfo *dinfo)
 228 {
 229     DrivePutRefBH *s;
 230
 231     s = g_new(DrivePutRefBH, 1);
 232     s->bh = qemu_bh_new(drive_put_ref_bh, s);
 233     s->dinfo = dinfo;
 234     qemu_bh_schedule(s->bh);
 235 }
 236
 237 static int parse_block_error_action(const char *buf, int is_read)
 238 {
 239     if (!strcmp(buf, "ignore")) {
 240         return BLOCK_ERR_IGNORE;
 241     } else if (!is_read && !strcmp(buf, "enospc")) {
 242         return BLOCK_ERR_STOP_ENOSPC;
 243     } else if (!strcmp(buf, "stop")) {
 244         return BLOCK_ERR_STOP_ANY;
 245     } else if (!strcmp(buf, "report")) {
 246         return BLOCK_ERR_REPORT;
 247     } else {
 248         error_report("'%s' invalid %s error action",
 249                      buf, is_read ? "read" : "write");
 250         return -1;
 251     }
 252 }
 253
 254 static bool do_check_io_limits(BlockIOLimit *io_limits)
 255 {
 256     bool bps_flag;
 257     bool iops_flag;
 258
 259     assert(io_limits);
 260
 261     bps_flag  = (io_limits->bps[BLOCK_IO_LIMIT_TOTAL] != 0)
 262                  && ((io_limits->bps[BLOCK_IO_LIMIT_READ] != 0)
 263                  || (io_limits->bps[BLOCK_IO_LIMIT_WRITE] != 0));
 264     iops_flag = (io_limits->iops[BLOCK_IO_LIMIT_TOTAL] != 0)
 265                  && ((io_limits->iops[BLOCK_IO_LIMIT_READ] != 0)
 266                  || (io_limits->iops[BLOCK_IO_LIMIT_WRITE] != 0));
 267     if (bps_flag || iops_flag) {
 268         return false;
 269     }
 270
 271     return true;
 272 }
 273
 274 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
 275 {
 276     const char *buf;
 277     const char *file = NULL;
 278     char devname[128];
 279     const char *serial;
 280     const char *mediastr = "";
 281     BlockInterfaceType type;
 282     enum { MEDIA_DISK, MEDIA_CDROM } media;
 283     int bus_id, unit_id;
 284     int cyls, heads, secs, translation;
 285     BlockDriver *drv = NULL;
 286     int max_devs;
 287     int index;
 288     int ro = 0;
 289     int bdrv_flags = 0;
 290     int on_read_error, on_write_error;
 291     const char *devaddr;
 292     DriveInfo *dinfo;
 293     BlockIOLimit io_limits;
 294     int snapshot = 0;
 295     bool copy_on_read;
 296     int ret;
 297
 298     translation = BIOS_ATA_TRANSLATION_AUTO;
 299     media = MEDIA_DISK;
 300
 301     /* extract parameters */
 302     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 303     unit_id = qemu_opt_get_number(opts, "unit", -1);
 304     index   = qemu_opt_get_number(opts, "index", -1);
 305
 306     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 307     heads = qemu_opt_get_number(opts, "heads", 0);
 308     secs  = qemu_opt_get_number(opts, "secs", 0);
 309
 310     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 311     ro = qemu_opt_get_bool(opts, "readonly", 0);
 312     copy_on_read = qemu_opt_get_bool(opts, "copy-on-read", false);
 313
 314     file = qemu_opt_get(opts, "file");
 315     serial = qemu_opt_get(opts, "serial");
 316
 317     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 318         pstrcpy(devname, sizeof(devname), buf);
 319         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
 320             ;
 321         if (type == IF_COUNT) {
 322             error_report("unsupported bus type '%s'", buf);
 323             return NULL;
 324         }
 325     } else {
 326         type = default_to_scsi ? IF_SCSI : IF_IDE;
 327         pstrcpy(devname, sizeof(devname), if_name[type]);
 328     }
 329
 330     max_devs = if_max_devs[type];
 331
 332     if (cyls || heads || secs) {
 333         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 334             error_report("invalid physical cyls number");
 335             return NULL;
 336         }
 337         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 338             error_report("invalid physical heads number");
 339             return NULL;
 340         }
 341         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 342             error_report("invalid physical secs number");
 343             return NULL;
 344         }
 345     }
 346
 347     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 348         if (!cyls) {
 349             error_report("'%s' trans must be used with cyls, heads and secs",
 350                          buf);
 351             return NULL;
 352         }
 353         if (!strcmp(buf, "none"))
 354             translation = BIOS_ATA_TRANSLATION_NONE;
 355         else if (!strcmp(buf, "lba"))
 356             translation = BIOS_ATA_TRANSLATION_LBA;
 357         else if (!strcmp(buf, "auto"))
 358             translation = BIOS_ATA_TRANSLATION_AUTO;
 359         else {
 360             error_report("'%s' invalid translation type", buf);
 361             return NULL;
 362         }
 363     }
 364
 365     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 366         if (!strcmp(buf, "disk")) {
 367             media = MEDIA_DISK;
 368         } else if (!strcmp(buf, "cdrom")) {
 369             if (cyls || secs || heads) {
 370                 error_report("CHS can't be set with media=%s", buf);
 371                 return NULL;
 372             }
 373             media = MEDIA_CDROM;
 374         } else {
 375             error_report("'%s' invalid media", buf);
 376             return NULL;
 377         }
 378     }
 379
 380     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 381         if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
 382             error_report("invalid cache option");
 383             return NULL;
 384         }
 385     }
 386
 387 #ifdef CONFIG_LINUX_AIO
 388     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 389         if (!strcmp(buf, "native")) {
 390             bdrv_flags |= BDRV_O_NATIVE_AIO;
 391         } else if (!strcmp(buf, "threads")) {
 392             /* this is the default */
 393         } else {
 394            error_report("invalid aio option");
 395            return NULL;
 396         }
 397     }
 398 #endif
 399
 400     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 401        if (strcmp(buf, "?") == 0) {
 402            error_printf("Supported formats:");
 403            bdrv_iterate_format(bdrv_format_print, NULL);
 404            error_printf("\n");
 405            return NULL;
 406         }
 407         drv = bdrv_find_whitelisted_format(buf);
 408         if (!drv) {
 409             error_report("'%s' invalid format", buf);
 410             return NULL;
 411         }
 412     }
 413
 414     /* disk I/O throttling */
 415     io_limits.bps[BLOCK_IO_LIMIT_TOTAL]  =
 416                            qemu_opt_get_number(opts, "bps", 0);
 417     io_limits.bps[BLOCK_IO_LIMIT_READ]   =
 418                            qemu_opt_get_number(opts, "bps_rd", 0);
 419     io_limits.bps[BLOCK_IO_LIMIT_WRITE]  =
 420                            qemu_opt_get_number(opts, "bps_wr", 0);
 421     io_limits.iops[BLOCK_IO_LIMIT_TOTAL] =
 422                            qemu_opt_get_number(opts, "iops", 0);
 423     io_limits.iops[BLOCK_IO_LIMIT_READ]  =
 424                            qemu_opt_get_number(opts, "iops_rd", 0);
 425     io_limits.iops[BLOCK_IO_LIMIT_WRITE] =
 426                            qemu_opt_get_number(opts, "iops_wr", 0);
 427
 428     if (!do_check_io_limits(&io_limits)) {
 429         error_report("bps(iops) and bps_rd/bps_wr(iops_rd/iops_wr) "
 430                      "cannot be used at the same time");
 431         return NULL;
 432     }
 433
 434     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 435     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 436         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 437             error_report("werror is not supported by this bus type");
 438             return NULL;
 439         }
 440
 441         on_write_error = parse_block_error_action(buf, 0);
 442         if (on_write_error < 0) {
 443             return NULL;
 444         }
 445     }
 446
 447     on_read_error = BLOCK_ERR_REPORT;
 448     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 449         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 450             error_report("rerror is not supported by this bus type");
 451             return NULL;
 452         }
 453
 454         on_read_error = parse_block_error_action(buf, 1);
 455         if (on_read_error < 0) {
 456             return NULL;
 457         }
 458     }
 459
 460     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 461         if (type != IF_VIRTIO) {
 462             error_report("addr is not supported by this bus type");
 463             return NULL;
 464         }
 465     }
 466
 467     /* compute bus and unit according index */
 468
 469     if (index != -1) {
 470         if (bus_id != 0 || unit_id != -1) {
 471             error_report("index cannot be used with bus and unit");
 472             return NULL;
 473         }
 474         bus_id = drive_index_to_bus_id(type, index);
 475         unit_id = drive_index_to_unit_id(type, index);
 476     }
 477
 478     /* if user doesn't specify a unit_id,
 479      * try to find the first free
 480      */
 481
 482     if (unit_id == -1) {
 483        unit_id = 0;
 484        while (drive_get(type, bus_id, unit_id) != NULL) {
 485            unit_id++;
 486            if (max_devs && unit_id >= max_devs) {
 487                unit_id -= max_devs;
 488                bus_id++;
 489            }
 490        }
 491     }
 492
 493     /* check unit id */
 494
 495     if (max_devs && unit_id >= max_devs) {
 496         error_report("unit %d too big (max is %d)",
 497                      unit_id, max_devs - 1);
 498         return NULL;
 499     }
 500
 501     /*
 502      * catch multiple definitions
 503      */
 504
 505     if (drive_get(type, bus_id, unit_id) != NULL) {
 506         error_report("drive with bus=%d, unit=%d (index=%d) exists",
 507                      bus_id, unit_id, index);
 508         return NULL;
 509     }
 510
 511     /* init */
 512
 513     dinfo = g_malloc0(sizeof(*dinfo));
 514     if ((buf = qemu_opts_id(opts)) != NULL) {
 515         dinfo->id = g_strdup(buf);
 516     } else {
 517         /* no id supplied -> create one */
 518         dinfo->id = g_malloc0(32);
 519         if (type == IF_IDE || type == IF_SCSI)
 520             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 521         if (max_devs)
 522             snprintf(dinfo->id, 32, "%s%i%s%i",
 523                      devname, bus_id, mediastr, unit_id);
 524         else
 525             snprintf(dinfo->id, 32, "%s%s%i",
 526                      devname, mediastr, unit_id);
 527     }
 528     dinfo->bdrv = bdrv_new(dinfo->id);
 529     dinfo->devaddr = devaddr;
 530     dinfo->type = type;
 531     dinfo->bus = bus_id;
 532     dinfo->unit = unit_id;
 533     dinfo->opts = opts;
 534     dinfo->refcount = 1;
 535     if (serial)
 536         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 537     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 538
 539     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 540
 541     /* disk I/O throttling */
 542     bdrv_set_io_limits(dinfo->bdrv, &io_limits);
 543
 544     switch(type) {
 545     case IF_IDE:
 546     case IF_SCSI:
 547     case IF_XEN:
 548     case IF_NONE:
 549         switch(media) {
 550         case MEDIA_DISK:
 551             if (cyls != 0) {
 552                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 553                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 554             }
 555             break;
 556         case MEDIA_CDROM:
 557             dinfo->media_cd = 1;
 558             break;
 559         }
 560         break;
 561     case IF_SD:
 562     case IF_FLOPPY:
 563     case IF_PFLASH:
 564     case IF_MTD:
 565         break;
 566     case IF_VIRTIO:
 567         /* add virtio block device */
 568         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 569         if (arch_type == QEMU_ARCH_S390X) {
 570             qemu_opt_set(opts, "driver", "virtio-blk-s390");
 571         } else {
 572             qemu_opt_set(opts, "driver", "virtio-blk-pci");
 573         }
 574         qemu_opt_set(opts, "drive", dinfo->id);
 575         if (devaddr)
 576             qemu_opt_set(opts, "addr", devaddr);
 577         break;
 578     default:
 579         abort();
 580     }
 581     if (!file || !*file) {
 582         return dinfo;
 583     }
 584     if (snapshot) {
 585         /* always use cache=unsafe with snapshot */
 586         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 587         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 588     }
 589
 590     if (copy_on_read) {
 591         bdrv_flags |= BDRV_O_COPY_ON_READ;
 592     }
 593
 594     if (media == MEDIA_CDROM) {
 595         /* CDROM is fine for any interface, don't check.  */
 596         ro = 1;
 597     } else if (ro == 1) {
 598         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 599             error_report("readonly not supported by this bus type");
 600             goto err;
 601         }
 602     }
 603
 604     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 605
 606     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 607     if (ret < 0) {
 608         error_report("could not open disk image %s: %s",
 609                      file, strerror(-ret));
 610         goto err;
 611     }
 612
 613     if (bdrv_key_required(dinfo->bdrv))
 614         autostart = 0;
 615     return dinfo;
 616
 617 err:
 618     bdrv_delete(dinfo->bdrv);
 619     g_free(dinfo->id);
 620     QTAILQ_REMOVE(&drives, dinfo, next);
 621     g_free(dinfo);
 622     return NULL;
 623 }
 624
 625 void do_commit(Monitor *mon, const QDict *qdict)
 626 {
 627     const char *device = qdict_get_str(qdict, "device");
 628     BlockDriverState *bs;
 629
 630     if (!strcmp(device, "all")) {
 631         bdrv_commit_all();
 632     } else {
 633         int ret;
 634
 635         bs = bdrv_find(device);
 636         if (!bs) {
 637             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 638             return;
 639         }
 640         ret = bdrv_commit(bs);
 641         if (ret == -EBUSY) {
 642             qerror_report(QERR_DEVICE_IN_USE, device);
 643             return;
 644         }
 645     }
 646 }
 647
 648 void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
 649                                 bool has_format, const char *format,
 650                                 Error **errp)
 651 {
 652     BlockDriverState *bs;
 653     BlockDriver *drv, *old_drv, *proto_drv;
 654     int ret = 0;
 655     int flags;
 656     char old_filename[1024];
 657
 658     bs = bdrv_find(device);
 659     if (!bs) {
 660         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 661         return;
 662     }
 663     if (bdrv_in_use(bs)) {
 664         error_set(errp, QERR_DEVICE_IN_USE, device);
 665         return;
 666     }
 667
 668     pstrcpy(old_filename, sizeof(old_filename), bs->filename);
 669
 670     old_drv = bs->drv;
 671     flags = bs->open_flags;
 672
 673     if (!has_format) {
 674         format = "qcow2";
 675     }
 676
 677     drv = bdrv_find_format(format);
 678     if (!drv) {
 679         error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
 680         return;
 681     }
 682
 683     proto_drv = bdrv_find_protocol(snapshot_file);
 684     if (!proto_drv) {
 685         error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
 686         return;
 687     }
 688
 689     ret = bdrv_img_create(snapshot_file, format, bs->filename,
 690                           bs->drv->format_name, NULL, -1, flags);
 691     if (ret) {
 692         error_set(errp, QERR_UNDEFINED_ERROR);
 693         return;
 694     }
 695
 696     bdrv_drain_all();
 697     bdrv_flush(bs);
 698
 699     bdrv_close(bs);
 700     ret = bdrv_open(bs, snapshot_file, flags, drv);
 701     /*
 702      * If reopening the image file we just created fails, fall back
 703      * and try to re-open the original image. If that fails too, we
 704      * are in serious trouble.
 705      */
 706     if (ret != 0) {
 707         ret = bdrv_open(bs, old_filename, flags, old_drv);
 708         if (ret != 0) {
 709             error_set(errp, QERR_OPEN_FILE_FAILED, old_filename);
 710         } else {
 711             error_set(errp, QERR_OPEN_FILE_FAILED, snapshot_file);
 712         }
 713     }
 714 }
 715
 716 static void eject_device(BlockDriverState *bs, int force, Error **errp)
 717 {
 718     if (bdrv_in_use(bs)) {
 719         error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
 720         return;
 721     }
 722     if (!bdrv_dev_has_removable_media(bs)) {
 723         error_set(errp, QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
 724         return;
 725     }
 726
 727     if (bdrv_dev_is_medium_locked(bs) && !bdrv_dev_is_tray_open(bs)) {
 728         bdrv_dev_eject_request(bs, force);
 729         if (!force) {
 730             error_set(errp, QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 731             return;
 732         }
 733     }
 734
 735     bdrv_close(bs);
 736 }
 737
 738 void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
 739 {
 740     BlockDriverState *bs;
 741
 742     bs = bdrv_find(device);
 743     if (!bs) {
 744         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 745         return;
 746     }
 747
 748     eject_device(bs, force, errp);
 749 }
 750
 751 void qmp_block_passwd(const char *device, const char *password, Error **errp)
 752 {
 753     BlockDriverState *bs;
 754     int err;
 755
 756     bs = bdrv_find(device);
 757     if (!bs) {
 758         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 759         return;
 760     }
 761
 762     err = bdrv_set_key(bs, password);
 763     if (err == -EINVAL) {
 764         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 765         return;
 766     } else if (err < 0) {
 767         error_set(errp, QERR_INVALID_PASSWORD);
 768         return;
 769     }
 770 }
 771
 772 static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
 773                                     int bdrv_flags, BlockDriver *drv,
 774                                     const char *password, Error **errp)
 775 {
 776     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 777         error_set(errp, QERR_OPEN_FILE_FAILED, filename);
 778         return;
 779     }
 780
 781     if (bdrv_key_required(bs)) {
 782         if (password) {
 783             if (bdrv_set_key(bs, password) < 0) {
 784                 error_set(errp, QERR_INVALID_PASSWORD);
 785             }
 786         } else {
 787             error_set(errp, QERR_DEVICE_ENCRYPTED, bdrv_get_device_name(bs),
 788                       bdrv_get_encrypted_filename(bs));
 789         }
 790     } else if (password) {
 791         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 792     }
 793 }
 794
 795 void qmp_change_blockdev(const char *device, const char *filename,
 796                          bool has_format, const char *format, Error **errp)
 797 {
 798     BlockDriverState *bs;
 799     BlockDriver *drv = NULL;
 800     int bdrv_flags;
 801     Error *err = NULL;
 802
 803     bs = bdrv_find(device);
 804     if (!bs) {
 805         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 806         return;
 807     }
 808
 809     if (format) {
 810         drv = bdrv_find_whitelisted_format(format);
 811         if (!drv) {
 812             error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
 813             return;
 814         }
 815     }
 816
 817     eject_device(bs, 0, &err);
 818     if (error_is_set(&err)) {
 819         error_propagate(errp, err);
 820         return;
 821     }
 822
 823     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 824     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 825
 826     qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, NULL, errp);
 827 }
 828
 829 /* throttling disk I/O limits */
 830 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
 831                                int64_t bps_wr, int64_t iops, int64_t iops_rd,
 832                                int64_t iops_wr, Error **errp)
 833 {
 834     BlockIOLimit io_limits;
 835     BlockDriverState *bs;
 836
 837     bs = bdrv_find(device);
 838     if (!bs) {
 839         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 840         return;
 841     }
 842
 843     io_limits.bps[BLOCK_IO_LIMIT_TOTAL] = bps;
 844     io_limits.bps[BLOCK_IO_LIMIT_READ]  = bps_rd;
 845     io_limits.bps[BLOCK_IO_LIMIT_WRITE] = bps_wr;
 846     io_limits.iops[BLOCK_IO_LIMIT_TOTAL]= iops;
 847     io_limits.iops[BLOCK_IO_LIMIT_READ] = iops_rd;
 848     io_limits.iops[BLOCK_IO_LIMIT_WRITE]= iops_wr;
 849
 850     if (!do_check_io_limits(&io_limits)) {
 851         error_set(errp, QERR_INVALID_PARAMETER_COMBINATION);
 852         return;
 853     }
 854
 855     bs->io_limits = io_limits;
 856     bs->slice_time = BLOCK_IO_SLICE_TIME;
 857
 858     if (!bs->io_limits_enabled && bdrv_io_limits_enabled(bs)) {
 859         bdrv_io_limits_enable(bs);
 860     } else if (bs->io_limits_enabled && !bdrv_io_limits_enabled(bs)) {
 861         bdrv_io_limits_disable(bs);
 862     } else {
 863         if (bs->block_timer) {
 864             qemu_mod_timer(bs->block_timer, qemu_get_clock_ns(vm_clock));
 865         }
 866     }
 867 }
 868
 869 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 870 {
 871     const char *id = qdict_get_str(qdict, "id");
 872     BlockDriverState *bs;
 873
 874     bs = bdrv_find(id);
 875     if (!bs) {
 876         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 877         return -1;
 878     }
 879     if (bdrv_in_use(bs)) {
 880         qerror_report(QERR_DEVICE_IN_USE, id);
 881         return -1;
 882     }
 883
 884     /* quiesce block driver; prevent further io */
 885     bdrv_drain_all();
 886     bdrv_flush(bs);
 887     bdrv_close(bs);
 888
 889     /* if we have a device attached to this BlockDriverState
 890      * then we need to make the drive anonymous until the device
 891      * can be removed.  If this is a drive with no device backing
 892      * then we can just get rid of the block driver state right here.
 893      */
 894     if (bdrv_get_attached_dev(bs)) {
 895         bdrv_make_anon(bs);
 896     } else {
 897         drive_uninit(drive_get_by_blockdev(bs));
 898     }
 899
 900     return 0;
 901 }
 902
 903 void qmp_block_resize(const char *device, int64_t size, Error **errp)
 904 {
 905     BlockDriverState *bs;
 906
 907     bs = bdrv_find(device);
 908     if (!bs) {
 909         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 910         return;
 911     }
 912
 913     if (size < 0) {
 914         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
 915         return;
 916     }
 917
 918     switch (bdrv_truncate(bs, size)) {
 919     case 0:
 920         break;
 921     case -ENOMEDIUM:
 922         error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
 923         break;
 924     case -ENOTSUP:
 925         error_set(errp, QERR_UNSUPPORTED);
 926         break;
 927     case -EACCES:
 928         error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
 929         break;
 930     case -EBUSY:
 931         error_set(errp, QERR_DEVICE_IN_USE, device);
 932         break;
 933     default:
 934         error_set(errp, QERR_UNDEFINED_ERROR);
 935         break;
 936     }
 937 }
 938
 939 static QObject *qobject_from_block_job(BlockJob *job)
 940 {
 941     return qobject_from_jsonf("{ 'type': %s,"
 942                               "'device': %s,"
 943                               "'len': %" PRId64 ","
 944                               "'offset': %" PRId64 ","
 945                               "'speed': %" PRId64 " }",
 946                               job->job_type->job_type,
 947                               bdrv_get_device_name(job->bs),
 948                               job->len,
 949                               job->offset,
 950                               job->speed);
 951 }
 952
 953 static void block_stream_cb(void *opaque, int ret)
 954 {
 955     BlockDriverState *bs = opaque;
 956     QObject *obj;
 957
 958     trace_block_stream_cb(bs, bs->job, ret);
 959
 960     assert(bs->job);
 961     obj = qobject_from_block_job(bs->job);
 962     if (ret < 0) {
 963         QDict *dict = qobject_to_qdict(obj);
 964         qdict_put(dict, "error", qstring_from_str(strerror(-ret)));
 965     }
 966
 967     if (block_job_is_cancelled(bs->job)) {
 968         monitor_protocol_event(QEVENT_BLOCK_JOB_CANCELLED, obj);
 969     } else {
 970         monitor_protocol_event(QEVENT_BLOCK_JOB_COMPLETED, obj);
 971     }
 972     qobject_decref(obj);
 973
 974     drive_put_ref_bh_schedule(drive_get_by_blockdev(bs));
 975 }
 976
 977 void qmp_block_stream(const char *device, bool has_base,
 978                       const char *base, Error **errp)
 979 {
 980     BlockDriverState *bs;
 981     BlockDriverState *base_bs = NULL;
 982     int ret;
 983
 984     bs = bdrv_find(device);
 985     if (!bs) {
 986         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 987         return;
 988     }
 989
 990     if (base) {
 991         base_bs = bdrv_find_backing_image(bs, base);
 992         if (base_bs == NULL) {
 993             error_set(errp, QERR_BASE_NOT_FOUND, base);
 994             return;
 995         }
 996     }
 997
 998     ret = stream_start(bs, base_bs, base, block_stream_cb, bs);
 999     if (ret < 0) {
1000         switch (ret) {
1001         case -EBUSY:
1002             error_set(errp, QERR_DEVICE_IN_USE, device);
1003             return;
1004         default:
1005             error_set(errp, QERR_NOT_SUPPORTED);
1006             return;
1007         }
1008     }
1009
1010     /* Grab a reference so hotplug does not delete the BlockDriverState from
1011      * underneath us.
1012      */
1013     drive_get_ref(drive_get_by_blockdev(bs));
1014
1015     trace_qmp_block_stream(bs, bs->job);
1016 }
1017
1018 static BlockJob *find_block_job(const char *device)
1019 {
1020     BlockDriverState *bs;
1021
1022     bs = bdrv_find(device);
1023     if (!bs || !bs->job) {
1024         return NULL;
1025     }
1026     return bs->job;
1027 }
1028
1029 void qmp_block_job_set_speed(const char *device, int64_t value, Error **errp)
1030 {
1031     BlockJob *job = find_block_job(device);
1032
1033     if (!job) {
1034         error_set(errp, QERR_DEVICE_NOT_ACTIVE, device);
1035         return;
1036     }
1037
1038     if (block_job_set_speed(job, value) < 0) {
1039         error_set(errp, QERR_NOT_SUPPORTED);
1040     }
1041 }
1042
1043 void qmp_block_job_cancel(const char *device, Error **errp)
1044 {
1045     BlockJob *job = find_block_job(device);
1046
1047     if (!job) {
1048         error_set(errp, QERR_DEVICE_NOT_ACTIVE, device);
1049         return;
1050     }
1051
1052     trace_qmp_block_job_cancel(job);
1053     block_job_cancel(job);
1054 }
1055
1056 static void do_qmp_query_block_jobs_one(void *opaque, BlockDriverState *bs)
1057 {
1058     BlockJobInfoList **prev = opaque;
1059     BlockJob *job = bs->job;
1060
1061     if (job) {
1062         BlockJobInfoList *elem;
1063         BlockJobInfo *info = g_new(BlockJobInfo, 1);
1064         *info = (BlockJobInfo){
1065             .type   = g_strdup(job->job_type->job_type),
1066             .device = g_strdup(bdrv_get_device_name(bs)),
1067             .len    = job->len,
1068             .offset = job->offset,
1069             .speed  = job->speed,
1070         };
1071
1072         elem = g_new0(BlockJobInfoList, 1);
1073         elem->value = info;
1074
1075         (*prev)->next = elem;
1076         *prev = elem;
1077     }
1078 }
1079
1080 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
1081 {
1082     /* Dummy is a fake list element for holding the head pointer */
1083     BlockJobInfoList dummy = {};
1084     BlockJobInfoList *prev = &dummy;
1085     bdrv_iterate(do_qmp_query_block_jobs_one, &prev);
1086     return dummy.next;
1087 }