hw/block/xen-block.c

   1 /*
   2  * Copyright (c) 2018  Citrix Systems Inc.
   3  *
   4  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   5  * See the COPYING file in the top-level directory.
   6  */
   7
   8 #include "qemu/osdep.h"
   9 #include "qemu/cutils.h"
  10 #include "qemu/option.h"
  11 #include "qapi/error.h"
  12 #include "qapi/qapi-commands-block-core.h"
  13 #include "qapi/qapi-commands-misc.h"
  14 #include "qapi/qapi-visit-block-core.h"
  15 #include "qapi/qobject-input-visitor.h"
  16 #include "qapi/visitor.h"
  17 #include "qapi/qmp/qdict.h"
  18 #include "qapi/qmp/qstring.h"
  19 #include "hw/hw.h"
  20 #include "hw/xen/xen_common.h"
  21 #include "hw/block/xen_blkif.h"
  22 #include "hw/xen/xen-block.h"
  23 #include "hw/xen/xen-backend.h"
  24 #include "sysemu/blockdev.h"
  25 #include "sysemu/block-backend.h"
  26 #include "sysemu/iothread.h"
  27 #include "dataplane/xen-block.h"
  28 #include "trace.h"
  29
  30 static char *xen_block_get_name(XenDevice *xendev, Error **errp)
  31 {
  32     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  33     XenBlockVdev *vdev = &blockdev->props.vdev;
  34
  35     return g_strdup_printf("%lu", vdev->number);
  36 }
  37
  38 static void xen_block_disconnect(XenDevice *xendev, Error **errp)
  39 {
  40     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  41     const char *type = object_get_typename(OBJECT(blockdev));
  42     XenBlockVdev *vdev = &blockdev->props.vdev;
  43
  44     trace_xen_block_disconnect(type, vdev->disk, vdev->partition);
  45
  46     xen_block_dataplane_stop(blockdev->dataplane);
  47 }
  48
  49 static void xen_block_connect(XenDevice *xendev, Error **errp)
  50 {
  51     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  52     const char *type = object_get_typename(OBJECT(blockdev));
  53     XenBlockVdev *vdev = &blockdev->props.vdev;
  54     unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol;
  55     char *str;
  56
  57     trace_xen_block_connect(type, vdev->disk, vdev->partition);
  58
  59     if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u",
  60                                   &order) != 1) {
  61         nr_ring_ref = 1;
  62         ring_ref = g_new(unsigned int, nr_ring_ref);
  63
  64         if (xen_device_frontend_scanf(xendev, "ring-ref", "%u",
  65                                       &ring_ref[0]) != 1) {
  66             error_setg(errp, "failed to read ring-ref");
  67             g_free(ring_ref);
  68             return;
  69         }
  70     } else if (order <= blockdev->props.max_ring_page_order) {
  71         unsigned int i;
  72
  73         nr_ring_ref = 1 << order;
  74         ring_ref = g_new(unsigned int, nr_ring_ref);
  75
  76         for (i = 0; i < nr_ring_ref; i++) {
  77             const char *key = g_strdup_printf("ring-ref%u", i);
  78
  79             if (xen_device_frontend_scanf(xendev, key, "%u",
  80                                           &ring_ref[i]) != 1) {
  81                 error_setg(errp, "failed to read %s", key);
  82                 g_free((gpointer)key);
  83                 g_free(ring_ref);
  84                 return;
  85             }
  86
  87             g_free((gpointer)key);
  88         }
  89     } else {
  90         error_setg(errp, "invalid ring-page-order (%d)", order);
  91         return;
  92     }
  93
  94     if (xen_device_frontend_scanf(xendev, "event-channel", "%u",
  95                                   &event_channel) != 1) {
  96         error_setg(errp, "failed to read event-channel");
  97         g_free(ring_ref);
  98         return;
  99     }
 100
 101     if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
 102                                   &str) != 1) {
 103         protocol = BLKIF_PROTOCOL_NATIVE;
 104     } else {
 105         if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
 106             protocol = BLKIF_PROTOCOL_X86_32;
 107         } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) {
 108             protocol = BLKIF_PROTOCOL_X86_64;
 109         } else {
 110             protocol = BLKIF_PROTOCOL_NATIVE;
 111         }
 112
 113         free(str);
 114     }
 115
 116     xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref,
 117                               event_channel, protocol, errp);
 118
 119     g_free(ring_ref);
 120 }
 121
 122 static void xen_block_unrealize(XenDevice *xendev, Error **errp)
 123 {
 124     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 125     XenBlockDeviceClass *blockdev_class =
 126         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 127     const char *type = object_get_typename(OBJECT(blockdev));
 128     XenBlockVdev *vdev = &blockdev->props.vdev;
 129
 130     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
 131         return;
 132     }
 133
 134     trace_xen_block_unrealize(type, vdev->disk, vdev->partition);
 135
 136     /* Disconnect from the frontend in case this has not already happened */
 137     xen_block_disconnect(xendev, NULL);
 138
 139     xen_block_dataplane_destroy(blockdev->dataplane);
 140     blockdev->dataplane = NULL;
 141
 142     if (blockdev_class->unrealize) {
 143         blockdev_class->unrealize(blockdev, errp);
 144     }
 145 }
 146
 147 static void xen_block_set_size(XenBlockDevice *blockdev)
 148 {
 149     const char *type = object_get_typename(OBJECT(blockdev));
 150     XenBlockVdev *vdev = &blockdev->props.vdev;
 151     BlockConf *conf = &blockdev->props.conf;
 152     int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size;
 153     XenDevice *xendev = XEN_DEVICE(blockdev);
 154
 155     trace_xen_block_size(type, vdev->disk, vdev->partition, sectors);
 156
 157     xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors);
 158 }
 159
 160 static void xen_block_resize_cb(void *opaque)
 161 {
 162     XenBlockDevice *blockdev = opaque;
 163     XenDevice *xendev = XEN_DEVICE(blockdev);
 164     enum xenbus_state state = xen_device_backend_get_state(xendev);
 165
 166     xen_block_set_size(blockdev);
 167
 168     /*
 169      * Mimic the behaviour of Linux xen-blkback and re-write the state
 170      * to trigger the frontend watch.
 171      */
 172     xen_device_backend_printf(xendev, "state", "%u", state);
 173 }
 174
 175 static const BlockDevOps xen_block_dev_ops = {
 176     .resize_cb = xen_block_resize_cb,
 177 };
 178
 179 static void xen_block_realize(XenDevice *xendev, Error **errp)
 180 {
 181     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 182     XenBlockDeviceClass *blockdev_class =
 183         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 184     const char *type = object_get_typename(OBJECT(blockdev));
 185     XenBlockVdev *vdev = &blockdev->props.vdev;
 186     BlockConf *conf = &blockdev->props.conf;
 187     Error *local_err = NULL;
 188
 189     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
 190         error_setg(errp, "vdev property not set");
 191         return;
 192     }
 193
 194     trace_xen_block_realize(type, vdev->disk, vdev->partition);
 195
 196     if (blockdev_class->realize) {
 197         blockdev_class->realize(blockdev, &local_err);
 198         if (local_err) {
 199             error_propagate(errp, local_err);
 200             return;
 201         }
 202     }
 203
 204     /*
 205      * The blkif protocol does not deal with removable media, so it must
 206      * always be present, even for CDRom devices.
 207      */
 208     assert(conf->blk);
 209     if (!blk_is_inserted(conf->blk)) {
 210         error_setg(errp, "device needs media, but drive is empty");
 211         return;
 212     }
 213
 214     if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
 215                                        true, errp)) {
 216         return;
 217     }
 218
 219     if (!(blockdev->info & VDISK_CDROM) &&
 220         !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) {
 221         return;
 222     }
 223
 224     blkconf_blocksizes(conf);
 225
 226     if (conf->logical_block_size > conf->physical_block_size) {
 227         error_setg(
 228             errp, "logical_block_size > physical_block_size not supported");
 229         return;
 230     }
 231
 232     blk_set_dev_ops(conf->blk, &xen_block_dev_ops, blockdev);
 233     blk_set_guest_block_size(conf->blk, conf->logical_block_size);
 234
 235     if (conf->discard_granularity == -1) {
 236         conf->discard_granularity = conf->physical_block_size;
 237     }
 238
 239     if (blk_get_flags(conf->blk) & BDRV_O_UNMAP) {
 240         xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
 241         xen_device_backend_printf(xendev, "discard-granularity", "%u",
 242                                   conf->discard_granularity);
 243     }
 244
 245     xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
 246     xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
 247                               blockdev->props.max_ring_page_order);
 248     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
 249
 250     xen_device_frontend_printf(xendev, "virtual-device", "%lu",
 251                                vdev->number);
 252     xen_device_frontend_printf(xendev, "device-type", "%s",
 253                                blockdev->device_type);
 254
 255     xen_device_backend_printf(xendev, "sector-size", "%u",
 256                               conf->logical_block_size);
 257
 258     xen_block_set_size(blockdev);
 259
 260     blockdev->dataplane =
 261         xen_block_dataplane_create(xendev, conf, blockdev->props.iothread);
 262 }
 263
 264 static void xen_block_frontend_changed(XenDevice *xendev,
 265                                        enum xenbus_state frontend_state,
 266                                        Error **errp)
 267 {
 268     enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
 269     Error *local_err = NULL;
 270
 271     switch (frontend_state) {
 272     case XenbusStateInitialised:
 273     case XenbusStateConnected:
 274         if (backend_state == XenbusStateConnected) {
 275             break;
 276         }
 277
 278         xen_block_disconnect(xendev, &local_err);
 279         if (local_err) {
 280             error_propagate(errp, local_err);
 281             break;
 282         }
 283
 284         xen_block_connect(xendev, &local_err);
 285         if (local_err) {
 286             error_propagate(errp, local_err);
 287             break;
 288         }
 289
 290         xen_device_backend_set_state(xendev, XenbusStateConnected);
 291         break;
 292
 293     case XenbusStateClosing:
 294         xen_device_backend_set_state(xendev, XenbusStateClosing);
 295         break;
 296
 297     case XenbusStateClosed:
 298         xen_block_disconnect(xendev, &local_err);
 299         if (local_err) {
 300             error_propagate(errp, local_err);
 301             break;
 302         }
 303
 304         xen_device_backend_set_state(xendev, XenbusStateClosed);
 305         break;
 306
 307     default:
 308         break;
 309     }
 310 }
 311
 312 static char *disk_to_vbd_name(unsigned int disk)
 313 {
 314     char *name, *prefix = (disk >= 26) ?
 315         disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
 316
 317     name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26);
 318     g_free(prefix);
 319
 320     return name;
 321 }
 322
 323 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
 324                                void *opaque, Error **errp)
 325 {
 326     DeviceState *dev = DEVICE(obj);
 327     Property *prop = opaque;
 328     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 329     char *str;
 330
 331     switch (vdev->type) {
 332     case XEN_BLOCK_VDEV_TYPE_DP:
 333         str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
 334         break;
 335
 336     case XEN_BLOCK_VDEV_TYPE_XVD:
 337     case XEN_BLOCK_VDEV_TYPE_HD:
 338     case XEN_BLOCK_VDEV_TYPE_SD: {
 339         char *name = disk_to_vbd_name(vdev->disk);
 340
 341         str = g_strdup_printf("%s%s%lu",
 342                               (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
 343                               "xvd" :
 344                               (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
 345                               "hd" :
 346                               "sd",
 347                               name, vdev->partition);
 348         g_free(name);
 349         break;
 350     }
 351     default:
 352         error_setg(errp, "invalid vdev type");
 353         return;
 354     }
 355
 356     visit_type_str(v, name, &str, errp);
 357     g_free(str);
 358 }
 359
 360 static int vbd_name_to_disk(const char *name, const char **endp,
 361                             unsigned long *disk)
 362 {
 363     unsigned int n = 0;
 364
 365     while (*name != '\0') {
 366         if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
 367             break;
 368         }
 369
 370         n *= 26;
 371         n += *name++ - 'a' + 1;
 372     }
 373     *endp = name;
 374
 375     if (!n) {
 376         return -1;
 377     }
 378
 379     *disk = n - 1;
 380
 381     return 0;
 382 }
 383
 384 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
 385                                void *opaque, Error **errp)
 386 {
 387     DeviceState *dev = DEVICE(obj);
 388     Property *prop = opaque;
 389     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 390     Error *local_err = NULL;
 391     char *str, *p;
 392     const char *end;
 393
 394     if (dev->realized) {
 395         qdev_prop_set_after_realize(dev, name, errp);
 396         return;
 397     }
 398
 399     visit_type_str(v, name, &str, &local_err);
 400     if (local_err) {
 401         error_propagate(errp, local_err);
 402         return;
 403     }
 404
 405     p = strchr(str, 'd');
 406     if (!p) {
 407         goto invalid;
 408     }
 409
 410     *p++ = '\0';
 411     if (*str == '\0') {
 412         vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
 413     } else if (strcmp(str, "xv") == 0) {
 414         vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
 415     } else if (strcmp(str, "h") == 0) {
 416         vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
 417     } else if (strcmp(str, "s") == 0) {
 418         vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
 419     } else {
 420         goto invalid;
 421     }
 422
 423     if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
 424         if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
 425             goto invalid;
 426         }
 427
 428         if (*end == 'p') {
 429             if (*(++end) == '\0') {
 430                 goto invalid;
 431             }
 432         }
 433     } else {
 434         if (vbd_name_to_disk(p, &end, &vdev->disk)) {
 435             goto invalid;
 436         }
 437     }
 438
 439     if (*end != '\0') {
 440         p = (char *)end;
 441
 442         if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
 443             goto invalid;
 444         }
 445
 446         if (*end != '\0') {
 447             goto invalid;
 448         }
 449     } else {
 450         vdev->partition = 0;
 451     }
 452
 453     switch (vdev->type) {
 454     case XEN_BLOCK_VDEV_TYPE_DP:
 455     case XEN_BLOCK_VDEV_TYPE_XVD:
 456         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 457             vdev->number = (202 << 8) | (vdev->disk << 4) |
 458                 vdev->partition;
 459         } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
 460             vdev->number = (1 << 28) | (vdev->disk << 8) |
 461                 vdev->partition;
 462         } else {
 463             goto invalid;
 464         }
 465         break;
 466
 467     case XEN_BLOCK_VDEV_TYPE_HD:
 468         if ((vdev->disk == 0 || vdev->disk == 1) &&
 469             vdev->partition < (1 << 6)) {
 470             vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
 471         } else if ((vdev->disk == 2 || vdev->disk == 3) &&
 472                    vdev->partition < (1 << 6)) {
 473             vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
 474                 vdev->partition;
 475         } else {
 476             goto invalid;
 477         }
 478         break;
 479
 480     case XEN_BLOCK_VDEV_TYPE_SD:
 481         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 482             vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
 483         } else {
 484             goto invalid;
 485         }
 486         break;
 487
 488     default:
 489         goto invalid;
 490     }
 491
 492     g_free(str);
 493     return;
 494
 495 invalid:
 496     error_setg(errp, "invalid virtual disk specifier");
 497
 498     vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
 499     g_free(str);
 500 }
 501
 502 /*
 503  * This property deals with 'vdev' names adhering to the Xen VBD naming
 504  * scheme described in:
 505  *
 506  * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
 507  */
 508 const PropertyInfo xen_block_prop_vdev = {
 509     .name  = "str",
 510     .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
 511     .get = xen_block_get_vdev,
 512     .set = xen_block_set_vdev,
 513 };
 514
 515 static Property xen_block_props[] = {
 516     DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
 517                 xen_block_prop_vdev, XenBlockVdev),
 518     DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
 519     DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
 520                        props.max_ring_page_order, 4),
 521     DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
 522                      TYPE_IOTHREAD, IOThread *),
 523     DEFINE_PROP_END_OF_LIST()
 524 };
 525
 526 static void xen_block_class_init(ObjectClass *class, void *data)
 527 {
 528     DeviceClass *dev_class = DEVICE_CLASS(class);
 529     XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
 530
 531     xendev_class->backend = "qdisk";
 532     xendev_class->device = "vbd";
 533     xendev_class->get_name = xen_block_get_name;
 534     xendev_class->realize = xen_block_realize;
 535     xendev_class->frontend_changed = xen_block_frontend_changed;
 536     xendev_class->unrealize = xen_block_unrealize;
 537
 538     dev_class->props = xen_block_props;
 539 }
 540
 541 static const TypeInfo xen_block_type_info = {
 542     .name = TYPE_XEN_BLOCK_DEVICE,
 543     .parent = TYPE_XEN_DEVICE,
 544     .instance_size = sizeof(XenBlockDevice),
 545     .abstract = true,
 546     .class_size = sizeof(XenBlockDeviceClass),
 547     .class_init = xen_block_class_init,
 548 };
 549
 550 static void xen_disk_unrealize(XenBlockDevice *blockdev, Error **errp)
 551 {
 552     trace_xen_disk_unrealize();
 553 }
 554
 555 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
 556 {
 557     BlockConf *conf = &blockdev->props.conf;
 558
 559     trace_xen_disk_realize();
 560
 561     blockdev->device_type = "disk";
 562
 563     if (!conf->blk) {
 564         error_setg(errp, "drive property not set");
 565         return;
 566     }
 567
 568     blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
 569 }
 570
 571 static void xen_disk_class_init(ObjectClass *class, void *data)
 572 {
 573     DeviceClass *dev_class = DEVICE_CLASS(class);
 574     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 575
 576     blockdev_class->realize = xen_disk_realize;
 577     blockdev_class->unrealize = xen_disk_unrealize;
 578
 579     dev_class->desc = "Xen Disk Device";
 580 }
 581
 582 static const TypeInfo xen_disk_type_info = {
 583     .name = TYPE_XEN_DISK_DEVICE,
 584     .parent = TYPE_XEN_BLOCK_DEVICE,
 585     .instance_size = sizeof(XenDiskDevice),
 586     .class_init = xen_disk_class_init,
 587 };
 588
 589 static void xen_cdrom_unrealize(XenBlockDevice *blockdev, Error **errp)
 590 {
 591     trace_xen_cdrom_unrealize();
 592 }
 593
 594 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
 595 {
 596     BlockConf *conf = &blockdev->props.conf;
 597
 598     trace_xen_cdrom_realize();
 599
 600     blockdev->device_type = "cdrom";
 601
 602     if (!conf->blk) {
 603         int rc;
 604
 605         /* Set up an empty drive */
 606         conf->blk = blk_new(0, BLK_PERM_ALL);
 607
 608         rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
 609         if (!rc) {
 610             error_setg_errno(errp, -rc, "failed to create drive");
 611             return;
 612         }
 613     }
 614
 615     blockdev->info = VDISK_READONLY | VDISK_CDROM;
 616 }
 617
 618 static void xen_cdrom_class_init(ObjectClass *class, void *data)
 619 {
 620     DeviceClass *dev_class = DEVICE_CLASS(class);
 621     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 622
 623     blockdev_class->realize = xen_cdrom_realize;
 624     blockdev_class->unrealize = xen_cdrom_unrealize;
 625
 626     dev_class->desc = "Xen CD-ROM Device";
 627 }
 628
 629 static const TypeInfo xen_cdrom_type_info = {
 630     .name = TYPE_XEN_CDROM_DEVICE,
 631     .parent = TYPE_XEN_BLOCK_DEVICE,
 632     .instance_size = sizeof(XenCDRomDevice),
 633     .class_init = xen_cdrom_class_init,
 634 };
 635
 636 static void xen_block_register_types(void)
 637 {
 638     type_register_static(&xen_block_type_info);
 639     type_register_static(&xen_disk_type_info);
 640     type_register_static(&xen_cdrom_type_info);
 641 }
 642
 643 type_init(xen_block_register_types)
 644
 645 static void xen_block_blockdev_del(const char *node_name, Error **errp)
 646 {
 647     trace_xen_block_blockdev_del(node_name);
 648
 649     qmp_blockdev_del(node_name, errp);
 650 }
 651
 652 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
 653                                     Error **errp)
 654 {
 655     const char *driver = qdict_get_try_str(qdict, "driver");
 656     BlockdevOptions *options = NULL;
 657     Error *local_err = NULL;
 658     char *node_name;
 659     Visitor *v;
 660
 661     if (!driver) {
 662         error_setg(errp, "no 'driver' parameter");
 663         return NULL;
 664     }
 665
 666     node_name = g_strdup_printf("%s-%s", id, driver);
 667     qdict_put_str(qdict, "node-name", node_name);
 668
 669     trace_xen_block_blockdev_add(node_name);
 670
 671     v = qobject_input_visitor_new(QOBJECT(qdict));
 672     visit_type_BlockdevOptions(v, NULL, &options, &local_err);
 673     visit_free(v);
 674
 675     if (local_err) {
 676         error_propagate(errp, local_err);
 677         goto fail;
 678     }
 679
 680     qmp_blockdev_add(options, &local_err);
 681
 682     if (local_err) {
 683         error_propagate(errp, local_err);
 684         goto fail;
 685     }
 686
 687     qapi_free_BlockdevOptions(options);
 688
 689     return node_name;
 690
 691 fail:
 692     if (options) {
 693         qapi_free_BlockdevOptions(options);
 694     }
 695     g_free(node_name);
 696
 697     return NULL;
 698 }
 699
 700 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
 701 {
 702     char *node_name = drive->node_name;
 703
 704     if (node_name) {
 705         Error *local_err = NULL;
 706
 707         xen_block_blockdev_del(node_name, &local_err);
 708         if (local_err) {
 709             error_propagate(errp, local_err);
 710             return;
 711         }
 712         g_free(node_name);
 713         drive->node_name = NULL;
 714     }
 715     g_free(drive->id);
 716     g_free(drive);
 717 }
 718
 719 static XenBlockDrive *xen_block_drive_create(const char *id,
 720                                              const char *device_type,
 721                                              QDict *opts, Error **errp)
 722 {
 723     const char *params = qdict_get_try_str(opts, "params");
 724     const char *mode = qdict_get_try_str(opts, "mode");
 725     const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
 726     const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
 727     char *driver = NULL;
 728     char *filename = NULL;
 729     XenBlockDrive *drive = NULL;
 730     Error *local_err = NULL;
 731     QDict *file_layer;
 732     QDict *driver_layer;
 733
 734     if (params) {
 735         char **v = g_strsplit(params, ":", 2);
 736
 737         if (v[1] == NULL) {
 738             filename = g_strdup(v[0]);
 739             driver = g_strdup("raw");
 740         } else {
 741             if (strcmp(v[0], "aio") == 0) {
 742                 driver = g_strdup("raw");
 743             } else if (strcmp(v[0], "vhd") == 0) {
 744                 driver = g_strdup("vpc");
 745             } else {
 746                 driver = g_strdup(v[0]);
 747             }
 748             filename = g_strdup(v[1]);
 749         }
 750
 751         g_strfreev(v);
 752     } else {
 753         error_setg(errp, "no params");
 754         goto done;
 755     }
 756
 757     assert(filename);
 758     assert(driver);
 759
 760     drive = g_new0(XenBlockDrive, 1);
 761     drive->id = g_strdup(id);
 762
 763     file_layer = qdict_new();
 764     driver_layer = qdict_new();
 765
 766     qdict_put_str(file_layer, "driver", "file");
 767     qdict_put_str(file_layer, "filename", filename);
 768     g_free(filename);
 769
 770     if (mode && *mode != 'w') {
 771         qdict_put_bool(file_layer, "read-only", true);
 772     }
 773
 774     if (direct_io_safe) {
 775         unsigned long value;
 776
 777         if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
 778             QDict *cache_qdict = qdict_new();
 779
 780             qdict_put_bool(cache_qdict, "direct", true);
 781             qdict_put(file_layer, "cache", cache_qdict);
 782
 783             qdict_put_str(file_layer, "aio", "native");
 784         }
 785     }
 786
 787     if (discard_enable) {
 788         unsigned long value;
 789
 790         if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
 791             qdict_put_str(file_layer, "discard", "unmap");
 792             qdict_put_str(driver_layer, "discard", "unmap");
 793         }
 794     }
 795
 796     /*
 797      * It is necessary to turn file locking off as an emulated device
 798      * may have already opened the same image file.
 799      */
 800     qdict_put_str(file_layer, "locking", "off");
 801
 802     qdict_put_str(driver_layer, "driver", driver);
 803     g_free(driver);
 804
 805     qdict_put(driver_layer, "file", file_layer);
 806
 807     g_assert(!drive->node_name);
 808     drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
 809                                               &local_err);
 810
 811     qobject_unref(driver_layer);
 812
 813 done:
 814     if (local_err) {
 815         error_propagate(errp, local_err);
 816         xen_block_drive_destroy(drive, NULL);
 817         return NULL;
 818     }
 819
 820     return drive;
 821 }
 822
 823 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
 824 {
 825     return drive->node_name ? drive->node_name : "";
 826 }
 827
 828 static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
 829                                        Error **errp)
 830 {
 831     qmp_object_del(iothread->id, errp);
 832
 833     g_free(iothread->id);
 834     g_free(iothread);
 835 }
 836
 837 static XenBlockIOThread *xen_block_iothread_create(const char *id,
 838                                                    Error **errp)
 839 {
 840     XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
 841     Error *local_err = NULL;
 842
 843     iothread->id = g_strdup(id);
 844
 845     qmp_object_add(TYPE_IOTHREAD, id, false, NULL, &local_err);
 846     if (local_err) {
 847         error_propagate(errp, local_err);
 848
 849         g_free(iothread->id);
 850         g_free(iothread);
 851         return NULL;
 852     }
 853
 854     return iothread;
 855 }
 856
 857 static void xen_block_device_create(XenBackendInstance *backend,
 858                                     QDict *opts, Error **errp)
 859 {
 860     XenBus *xenbus = xen_backend_get_bus(backend);
 861     const char *name = xen_backend_get_name(backend);
 862     unsigned long number;
 863     const char *vdev, *device_type;
 864     XenBlockDrive *drive = NULL;
 865     XenBlockIOThread *iothread = NULL;
 866     XenDevice *xendev = NULL;
 867     Error *local_err = NULL;
 868     const char *type;
 869     XenBlockDevice *blockdev;
 870
 871     if (qemu_strtoul(name, NULL, 10, &number)) {
 872         error_setg(errp, "failed to parse name '%s'", name);
 873         goto fail;
 874     }
 875
 876     trace_xen_block_device_create(number);
 877
 878     vdev = qdict_get_try_str(opts, "dev");
 879     if (!vdev) {
 880         error_setg(errp, "no dev parameter");
 881         goto fail;
 882     }
 883
 884     device_type = qdict_get_try_str(opts, "device-type");
 885     if (!device_type) {
 886         error_setg(errp, "no device-type parameter");
 887         goto fail;
 888     }
 889
 890     if (!strcmp(device_type, "disk")) {
 891         type = TYPE_XEN_DISK_DEVICE;
 892     } else if (!strcmp(device_type, "cdrom")) {
 893         type = TYPE_XEN_CDROM_DEVICE;
 894     } else {
 895         error_setg(errp, "invalid device-type parameter '%s'", device_type);
 896         goto fail;
 897     }
 898
 899     drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
 900     if (!drive) {
 901         error_propagate_prepend(errp, local_err, "failed to create drive: ");
 902         goto fail;
 903     }
 904
 905     iothread = xen_block_iothread_create(vdev, &local_err);
 906     if (local_err) {
 907         error_propagate_prepend(errp, local_err,
 908                                 "failed to create iothread: ");
 909         goto fail;
 910     }
 911
 912     xendev = XEN_DEVICE(qdev_create(BUS(xenbus), type));
 913     blockdev = XEN_BLOCK_DEVICE(xendev);
 914
 915     object_property_set_str(OBJECT(xendev), vdev, "vdev", &local_err);
 916     if (local_err) {
 917         error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
 918         goto fail;
 919     }
 920
 921     object_property_set_str(OBJECT(xendev),
 922                             xen_block_drive_get_node_name(drive), "drive",
 923                             &local_err);
 924     if (local_err) {
 925         error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
 926         goto fail;
 927     }
 928
 929     object_property_set_str(OBJECT(xendev), iothread->id, "iothread",
 930                             &local_err);
 931     if (local_err) {
 932         error_propagate_prepend(errp, local_err,
 933                                 "failed to set 'iothread': ");
 934         goto fail;
 935     }
 936
 937     blockdev->iothread = iothread;
 938     blockdev->drive = drive;
 939
 940     object_property_set_bool(OBJECT(xendev), true, "realized", &local_err);
 941     if (local_err) {
 942         error_propagate_prepend(errp, local_err,
 943                                 "realization of device %s failed: ",
 944                                 type);
 945         goto fail;
 946     }
 947
 948     xen_backend_set_device(backend, xendev);
 949     return;
 950
 951 fail:
 952     if (xendev) {
 953         object_unparent(OBJECT(xendev));
 954     }
 955
 956     if (iothread) {
 957         xen_block_iothread_destroy(iothread, NULL);
 958     }
 959
 960     if (drive) {
 961         xen_block_drive_destroy(drive, NULL);
 962     }
 963 }
 964
 965 static void xen_block_device_destroy(XenBackendInstance *backend,
 966                                      Error **errp)
 967 {
 968     XenDevice *xendev = xen_backend_get_device(backend);
 969     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 970     XenBlockVdev *vdev = &blockdev->props.vdev;
 971     XenBlockDrive *drive = blockdev->drive;
 972     XenBlockIOThread *iothread = blockdev->iothread;
 973
 974     trace_xen_block_device_destroy(vdev->number);
 975
 976     object_unparent(OBJECT(xendev));
 977
 978     if (iothread) {
 979         Error *local_err = NULL;
 980
 981         xen_block_iothread_destroy(iothread, &local_err);
 982         if (local_err) {
 983             error_propagate_prepend(errp, local_err,
 984                                 "failed to destroy iothread: ");
 985             return;
 986         }
 987     }
 988
 989     if (drive) {
 990         Error *local_err = NULL;
 991
 992         xen_block_drive_destroy(drive, &local_err);
 993         if (local_err) {
 994             error_propagate_prepend(errp, local_err,
 995                                 "failed to destroy drive: ");
 996         }
 997     }
 998 }
 999
1000 static const XenBackendInfo xen_block_backend_info = {
1001     .type = "qdisk",
1002     .create = xen_block_device_create,
1003     .destroy = xen_block_device_destroy,
1004 };
1005
1006 static void xen_block_register_backend(void)
1007 {
1008     xen_backend_register(&xen_block_backend_info);
1009 }
1010
1011 xen_backend_init(xen_block_register_backend);