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 > 0) {
 236         xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
 237     }
 238
 239     xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
 240     xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
 241                               blockdev->props.max_ring_page_order);
 242     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
 243
 244     xen_device_frontend_printf(xendev, "virtual-device", "%lu",
 245                                vdev->number);
 246     xen_device_frontend_printf(xendev, "device-type", "%s",
 247                                blockdev->device_type);
 248
 249     xen_device_backend_printf(xendev, "sector-size", "%u",
 250                               conf->logical_block_size);
 251
 252     xen_block_set_size(blockdev);
 253
 254     blockdev->dataplane =
 255         xen_block_dataplane_create(xendev, conf, blockdev->props.iothread);
 256 }
 257
 258 static void xen_block_frontend_changed(XenDevice *xendev,
 259                                        enum xenbus_state frontend_state,
 260                                        Error **errp)
 261 {
 262     enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
 263     Error *local_err = NULL;
 264
 265     switch (frontend_state) {
 266     case XenbusStateInitialised:
 267     case XenbusStateConnected:
 268         if (backend_state == XenbusStateConnected) {
 269             break;
 270         }
 271
 272         xen_block_disconnect(xendev, &local_err);
 273         if (local_err) {
 274             error_propagate(errp, local_err);
 275             break;
 276         }
 277
 278         xen_block_connect(xendev, &local_err);
 279         if (local_err) {
 280             error_propagate(errp, local_err);
 281             break;
 282         }
 283
 284         xen_device_backend_set_state(xendev, XenbusStateConnected);
 285         break;
 286
 287     case XenbusStateClosing:
 288         xen_device_backend_set_state(xendev, XenbusStateClosing);
 289         break;
 290
 291     case XenbusStateClosed:
 292         xen_block_disconnect(xendev, &local_err);
 293         if (local_err) {
 294             error_propagate(errp, local_err);
 295             break;
 296         }
 297
 298         xen_device_backend_set_state(xendev, XenbusStateClosed);
 299         break;
 300
 301     default:
 302         break;
 303     }
 304 }
 305
 306 static char *disk_to_vbd_name(unsigned int disk)
 307 {
 308     char *name, *prefix = (disk >= 26) ?
 309         disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
 310
 311     name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26);
 312     g_free(prefix);
 313
 314     return name;
 315 }
 316
 317 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
 318                                void *opaque, Error **errp)
 319 {
 320     DeviceState *dev = DEVICE(obj);
 321     Property *prop = opaque;
 322     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 323     char *str;
 324
 325     switch (vdev->type) {
 326     case XEN_BLOCK_VDEV_TYPE_DP:
 327         str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
 328         break;
 329
 330     case XEN_BLOCK_VDEV_TYPE_XVD:
 331     case XEN_BLOCK_VDEV_TYPE_HD:
 332     case XEN_BLOCK_VDEV_TYPE_SD: {
 333         char *name = disk_to_vbd_name(vdev->disk);
 334
 335         str = g_strdup_printf("%s%s%lu",
 336                               (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
 337                               "xvd" :
 338                               (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
 339                               "hd" :
 340                               "sd",
 341                               name, vdev->partition);
 342         g_free(name);
 343         break;
 344     }
 345     default:
 346         error_setg(errp, "invalid vdev type");
 347         return;
 348     }
 349
 350     visit_type_str(v, name, &str, errp);
 351     g_free(str);
 352 }
 353
 354 static unsigned int vbd_name_to_disk(const char *name, const char **endp)
 355 {
 356     unsigned int disk = 0;
 357
 358     while (*name != '\0') {
 359         if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
 360             break;
 361         }
 362
 363         disk *= 26;
 364         disk += *name++ - 'a' + 1;
 365     }
 366     *endp = name;
 367
 368     return disk - 1;
 369 }
 370
 371 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
 372                                void *opaque, Error **errp)
 373 {
 374     DeviceState *dev = DEVICE(obj);
 375     Property *prop = opaque;
 376     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 377     Error *local_err = NULL;
 378     char *str, *p;
 379     const char *end;
 380
 381     if (dev->realized) {
 382         qdev_prop_set_after_realize(dev, name, errp);
 383         return;
 384     }
 385
 386     visit_type_str(v, name, &str, &local_err);
 387     if (local_err) {
 388         error_propagate(errp, local_err);
 389         return;
 390     }
 391
 392     p = strchr(str, 'd');
 393     if (!p) {
 394         goto invalid;
 395     }
 396
 397     *p++ = '\0';
 398     if (*str == '\0') {
 399         vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
 400     } else if (strcmp(str, "xv") == 0) {
 401         vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
 402     } else if (strcmp(str, "h") == 0) {
 403         vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
 404     } else if (strcmp(str, "s") == 0) {
 405         vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
 406     } else {
 407         goto invalid;
 408     }
 409
 410     if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
 411         if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
 412             goto invalid;
 413         }
 414
 415         if (*end == 'p') {
 416             p = (char *) ++end;
 417             if (*end == '\0') {
 418                 goto invalid;
 419             }
 420         }
 421     } else {
 422         vdev->disk = vbd_name_to_disk(p, &end);
 423     }
 424
 425     if (*end != '\0') {
 426         p = (char *)end;
 427
 428         if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
 429             goto invalid;
 430         }
 431
 432         if (*end != '\0') {
 433             goto invalid;
 434         }
 435     } else {
 436         vdev->partition = 0;
 437     }
 438
 439     switch (vdev->type) {
 440     case XEN_BLOCK_VDEV_TYPE_DP:
 441     case XEN_BLOCK_VDEV_TYPE_XVD:
 442         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 443             vdev->number = (202 << 8) | (vdev->disk << 4) |
 444                 vdev->partition;
 445         } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
 446             vdev->number = (1 << 28) | (vdev->disk << 8) |
 447                 vdev->partition;
 448         } else {
 449             goto invalid;
 450         }
 451         break;
 452
 453     case XEN_BLOCK_VDEV_TYPE_HD:
 454         if ((vdev->disk == 0 || vdev->disk == 1) &&
 455             vdev->partition < (1 << 6)) {
 456             vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
 457         } else if ((vdev->disk == 2 || vdev->disk == 3) &&
 458                    vdev->partition < (1 << 6)) {
 459             vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
 460                 vdev->partition;
 461         } else {
 462             goto invalid;
 463         }
 464         break;
 465
 466     case XEN_BLOCK_VDEV_TYPE_SD:
 467         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 468             vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
 469         } else {
 470             goto invalid;
 471         }
 472         break;
 473
 474     default:
 475         goto invalid;
 476     }
 477
 478     g_free(str);
 479     return;
 480
 481 invalid:
 482     error_setg(errp, "invalid virtual disk specifier");
 483
 484     vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
 485     g_free(str);
 486 }
 487
 488 /*
 489  * This property deals with 'vdev' names adhering to the Xen VBD naming
 490  * scheme described in:
 491  *
 492  * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
 493  */
 494 const PropertyInfo xen_block_prop_vdev = {
 495     .name  = "str",
 496     .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
 497     .get = xen_block_get_vdev,
 498     .set = xen_block_set_vdev,
 499 };
 500
 501 static Property xen_block_props[] = {
 502     DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
 503                 xen_block_prop_vdev, XenBlockVdev),
 504     DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
 505     DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
 506                        props.max_ring_page_order, 4),
 507     DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
 508                      TYPE_IOTHREAD, IOThread *),
 509     DEFINE_PROP_END_OF_LIST()
 510 };
 511
 512 static void xen_block_class_init(ObjectClass *class, void *data)
 513 {
 514     DeviceClass *dev_class = DEVICE_CLASS(class);
 515     XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
 516
 517     xendev_class->backend = "qdisk";
 518     xendev_class->device = "vbd";
 519     xendev_class->get_name = xen_block_get_name;
 520     xendev_class->realize = xen_block_realize;
 521     xendev_class->frontend_changed = xen_block_frontend_changed;
 522     xendev_class->unrealize = xen_block_unrealize;
 523
 524     dev_class->props = xen_block_props;
 525 }
 526
 527 static const TypeInfo xen_block_type_info = {
 528     .name = TYPE_XEN_BLOCK_DEVICE,
 529     .parent = TYPE_XEN_DEVICE,
 530     .instance_size = sizeof(XenBlockDevice),
 531     .abstract = true,
 532     .class_size = sizeof(XenBlockDeviceClass),
 533     .class_init = xen_block_class_init,
 534 };
 535
 536 static void xen_disk_unrealize(XenBlockDevice *blockdev, Error **errp)
 537 {
 538     trace_xen_disk_unrealize();
 539 }
 540
 541 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
 542 {
 543     BlockConf *conf = &blockdev->props.conf;
 544
 545     trace_xen_disk_realize();
 546
 547     blockdev->device_type = "disk";
 548
 549     if (!conf->blk) {
 550         error_setg(errp, "drive property not set");
 551         return;
 552     }
 553
 554     blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
 555 }
 556
 557 static void xen_disk_class_init(ObjectClass *class, void *data)
 558 {
 559     DeviceClass *dev_class = DEVICE_CLASS(class);
 560     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 561
 562     blockdev_class->realize = xen_disk_realize;
 563     blockdev_class->unrealize = xen_disk_unrealize;
 564
 565     dev_class->desc = "Xen Disk Device";
 566 }
 567
 568 static const TypeInfo xen_disk_type_info = {
 569     .name = TYPE_XEN_DISK_DEVICE,
 570     .parent = TYPE_XEN_BLOCK_DEVICE,
 571     .instance_size = sizeof(XenDiskDevice),
 572     .class_init = xen_disk_class_init,
 573 };
 574
 575 static void xen_cdrom_unrealize(XenBlockDevice *blockdev, Error **errp)
 576 {
 577     trace_xen_cdrom_unrealize();
 578 }
 579
 580 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
 581 {
 582     BlockConf *conf = &blockdev->props.conf;
 583
 584     trace_xen_cdrom_realize();
 585
 586     blockdev->device_type = "cdrom";
 587
 588     if (!conf->blk) {
 589         int rc;
 590
 591         /* Set up an empty drive */
 592         conf->blk = blk_new(0, BLK_PERM_ALL);
 593
 594         rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
 595         if (!rc) {
 596             error_setg_errno(errp, -rc, "failed to create drive");
 597             return;
 598         }
 599     }
 600
 601     blockdev->info = VDISK_READONLY | VDISK_CDROM;
 602 }
 603
 604 static void xen_cdrom_class_init(ObjectClass *class, void *data)
 605 {
 606     DeviceClass *dev_class = DEVICE_CLASS(class);
 607     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 608
 609     blockdev_class->realize = xen_cdrom_realize;
 610     blockdev_class->unrealize = xen_cdrom_unrealize;
 611
 612     dev_class->desc = "Xen CD-ROM Device";
 613 }
 614
 615 static const TypeInfo xen_cdrom_type_info = {
 616     .name = TYPE_XEN_CDROM_DEVICE,
 617     .parent = TYPE_XEN_BLOCK_DEVICE,
 618     .instance_size = sizeof(XenCDRomDevice),
 619     .class_init = xen_cdrom_class_init,
 620 };
 621
 622 static void xen_block_register_types(void)
 623 {
 624     type_register_static(&xen_block_type_info);
 625     type_register_static(&xen_disk_type_info);
 626     type_register_static(&xen_cdrom_type_info);
 627 }
 628
 629 type_init(xen_block_register_types)
 630
 631 static void xen_block_blockdev_del(const char *node_name, Error **errp)
 632 {
 633     trace_xen_block_blockdev_del(node_name);
 634
 635     qmp_blockdev_del(node_name, errp);
 636 }
 637
 638 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
 639                                     Error **errp)
 640 {
 641     const char *driver = qdict_get_try_str(qdict, "driver");
 642     BlockdevOptions *options = NULL;
 643     Error *local_err = NULL;
 644     char *node_name;
 645     Visitor *v;
 646
 647     if (!driver) {
 648         error_setg(errp, "no 'driver' parameter");
 649         return NULL;
 650     }
 651
 652     node_name = g_strdup_printf("%s-%s", id, driver);
 653     qdict_put_str(qdict, "node-name", node_name);
 654
 655     trace_xen_block_blockdev_add(node_name);
 656
 657     v = qobject_input_visitor_new(QOBJECT(qdict));
 658     visit_type_BlockdevOptions(v, NULL, &options, &local_err);
 659     visit_free(v);
 660
 661     if (local_err) {
 662         error_propagate(errp, local_err);
 663         goto fail;
 664     }
 665
 666     qmp_blockdev_add(options, &local_err);
 667
 668     if (local_err) {
 669         error_propagate(errp, local_err);
 670         goto fail;
 671     }
 672
 673     qapi_free_BlockdevOptions(options);
 674
 675     return node_name;
 676
 677 fail:
 678     if (options) {
 679         qapi_free_BlockdevOptions(options);
 680     }
 681     g_free(node_name);
 682
 683     return NULL;
 684 }
 685
 686 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
 687 {
 688     char *node_name = drive->node_name;
 689
 690     if (node_name) {
 691         Error *local_err = NULL;
 692
 693         xen_block_blockdev_del(node_name, &local_err);
 694         if (local_err) {
 695             error_propagate(errp, local_err);
 696             return;
 697         }
 698         g_free(node_name);
 699         drive->node_name = NULL;
 700     }
 701     g_free(drive->id);
 702     g_free(drive);
 703 }
 704
 705 static XenBlockDrive *xen_block_drive_create(const char *id,
 706                                              const char *device_type,
 707                                              QDict *opts, Error **errp)
 708 {
 709     const char *params = qdict_get_try_str(opts, "params");
 710     const char *mode = qdict_get_try_str(opts, "mode");
 711     const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
 712     const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
 713     char *driver = NULL;
 714     char *filename = NULL;
 715     XenBlockDrive *drive = NULL;
 716     Error *local_err = NULL;
 717     QDict *file_layer;
 718     QDict *driver_layer;
 719
 720     if (params) {
 721         char **v = g_strsplit(params, ":", 2);
 722
 723         if (v[1] == NULL) {
 724             filename = g_strdup(v[0]);
 725             driver = g_strdup("raw");
 726         } else {
 727             if (strcmp(v[0], "aio") == 0) {
 728                 driver = g_strdup("raw");
 729             } else if (strcmp(v[0], "vhd") == 0) {
 730                 driver = g_strdup("vpc");
 731             } else {
 732                 driver = g_strdup(v[0]);
 733             }
 734             filename = g_strdup(v[1]);
 735         }
 736
 737         g_strfreev(v);
 738     }
 739
 740     if (!filename) {
 741         error_setg(errp, "no filename");
 742         goto done;
 743     }
 744     assert(driver);
 745
 746     drive = g_new0(XenBlockDrive, 1);
 747     drive->id = g_strdup(id);
 748
 749     file_layer = qdict_new();
 750
 751     qdict_put_str(file_layer, "driver", "file");
 752     qdict_put_str(file_layer, "filename", filename);
 753
 754     if (mode && *mode != 'w') {
 755         qdict_put_bool(file_layer, "read-only", true);
 756     }
 757
 758     if (direct_io_safe) {
 759         unsigned long value;
 760
 761         if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
 762             QDict *cache_qdict = qdict_new();
 763
 764             qdict_put_bool(cache_qdict, "direct", true);
 765             qdict_put_obj(file_layer, "cache", QOBJECT(cache_qdict));
 766
 767             qdict_put_str(file_layer, "aio", "native");
 768         }
 769     }
 770
 771     if (discard_enable) {
 772         unsigned long value;
 773
 774         if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
 775             qdict_put_str(file_layer, "discard", "unmap");
 776         }
 777     }
 778
 779     /*
 780      * It is necessary to turn file locking off as an emulated device
 781      * may have already opened the same image file.
 782      */
 783     qdict_put_str(file_layer, "locking", "off");
 784
 785     driver_layer = qdict_new();
 786
 787     qdict_put_str(driver_layer, "driver", driver);
 788     qdict_put_obj(driver_layer, "file", QOBJECT(file_layer));
 789
 790     g_assert(!drive->node_name);
 791     drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
 792                                               &local_err);
 793
 794 done:
 795     g_free(driver);
 796     g_free(filename);
 797
 798     if (local_err) {
 799         error_propagate(errp, local_err);
 800         xen_block_drive_destroy(drive, NULL);
 801         return NULL;
 802     }
 803
 804     return drive;
 805 }
 806
 807 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
 808 {
 809     return drive->node_name ? drive->node_name : "";
 810 }
 811
 812 static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
 813                                        Error **errp)
 814 {
 815     qmp_object_del(iothread->id, errp);
 816
 817     g_free(iothread->id);
 818     g_free(iothread);
 819 }
 820
 821 static XenBlockIOThread *xen_block_iothread_create(const char *id,
 822                                                    Error **errp)
 823 {
 824     XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
 825     Error *local_err = NULL;
 826
 827     iothread->id = g_strdup(id);
 828
 829     qmp_object_add(TYPE_IOTHREAD, id, false, NULL, &local_err);
 830     if (local_err) {
 831         error_propagate(errp, local_err);
 832
 833         g_free(iothread->id);
 834         g_free(iothread);
 835         return NULL;
 836     }
 837
 838     return iothread;
 839 }
 840
 841 static void xen_block_device_create(XenBackendInstance *backend,
 842                                     QDict *opts, Error **errp)
 843 {
 844     XenBus *xenbus = xen_backend_get_bus(backend);
 845     const char *name = xen_backend_get_name(backend);
 846     unsigned long number;
 847     const char *vdev, *device_type;
 848     XenBlockDrive *drive = NULL;
 849     XenBlockIOThread *iothread = NULL;
 850     XenDevice *xendev = NULL;
 851     Error *local_err = NULL;
 852     const char *type;
 853     XenBlockDevice *blockdev;
 854
 855     if (qemu_strtoul(name, NULL, 10, &number)) {
 856         error_setg(errp, "failed to parse name '%s'", name);
 857         goto fail;
 858     }
 859
 860     trace_xen_block_device_create(number);
 861
 862     vdev = qdict_get_try_str(opts, "dev");
 863     if (!vdev) {
 864         error_setg(errp, "no dev parameter");
 865         goto fail;
 866     }
 867
 868     device_type = qdict_get_try_str(opts, "device-type");
 869     if (!device_type) {
 870         error_setg(errp, "no device-type parameter");
 871         goto fail;
 872     }
 873
 874     if (!strcmp(device_type, "disk")) {
 875         type = TYPE_XEN_DISK_DEVICE;
 876     } else if (!strcmp(device_type, "cdrom")) {
 877         type = TYPE_XEN_CDROM_DEVICE;
 878     } else {
 879         error_setg(errp, "invalid device-type parameter '%s'", device_type);
 880         goto fail;
 881     }
 882
 883     drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
 884     if (!drive) {
 885         error_propagate_prepend(errp, local_err, "failed to create drive: ");
 886         goto fail;
 887     }
 888
 889     iothread = xen_block_iothread_create(vdev, &local_err);
 890     if (local_err) {
 891         error_propagate_prepend(errp, local_err,
 892                                 "failed to create iothread: ");
 893         goto fail;
 894     }
 895
 896     xendev = XEN_DEVICE(qdev_create(BUS(xenbus), type));
 897     blockdev = XEN_BLOCK_DEVICE(xendev);
 898
 899     object_property_set_str(OBJECT(xendev), vdev, "vdev", &local_err);
 900     if (local_err) {
 901         error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
 902         goto fail;
 903     }
 904
 905     object_property_set_str(OBJECT(xendev),
 906                             xen_block_drive_get_node_name(drive), "drive",
 907                             &local_err);
 908     if (local_err) {
 909         error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
 910         goto fail;
 911     }
 912
 913     object_property_set_str(OBJECT(xendev), iothread->id, "iothread",
 914                             &local_err);
 915     if (local_err) {
 916         error_propagate_prepend(errp, local_err,
 917                                 "failed to set 'iothread': ");
 918         goto fail;
 919     }
 920
 921     blockdev->iothread = iothread;
 922     blockdev->drive = drive;
 923
 924     object_property_set_bool(OBJECT(xendev), true, "realized", &local_err);
 925     if (local_err) {
 926         error_propagate_prepend(errp, local_err,
 927                                 "realization of device %s failed: ",
 928                                 type);
 929         goto fail;
 930     }
 931
 932     xen_backend_set_device(backend, xendev);
 933     return;
 934
 935 fail:
 936     if (xendev) {
 937         object_unparent(OBJECT(xendev));
 938     }
 939
 940     if (iothread) {
 941         xen_block_iothread_destroy(iothread, NULL);
 942     }
 943
 944     if (drive) {
 945         xen_block_drive_destroy(drive, NULL);
 946     }
 947 }
 948
 949 static void xen_block_device_destroy(XenBackendInstance *backend,
 950                                      Error **errp)
 951 {
 952     XenDevice *xendev = xen_backend_get_device(backend);
 953     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 954     XenBlockVdev *vdev = &blockdev->props.vdev;
 955     XenBlockDrive *drive = blockdev->drive;
 956     XenBlockIOThread *iothread = blockdev->iothread;
 957
 958     trace_xen_block_device_destroy(vdev->number);
 959
 960     object_unparent(OBJECT(xendev));
 961
 962     if (iothread) {
 963         Error *local_err = NULL;
 964
 965         xen_block_iothread_destroy(iothread, &local_err);
 966         if (local_err) {
 967             error_propagate_prepend(errp, local_err,
 968                                 "failed to destroy iothread: ");
 969             return;
 970         }
 971     }
 972
 973     if (drive) {
 974         Error *local_err = NULL;
 975
 976         xen_block_drive_destroy(drive, &local_err);
 977         if (local_err) {
 978             error_propagate_prepend(errp, local_err,
 979                                 "failed to destroy drive: ");
 980         }
 981     }
 982 }
 983
 984 static const XenBackendInfo xen_block_backend_info = {
 985     .type = "qdisk",
 986     .create = xen_block_device_create,
 987     .destroy = xen_block_device_destroy,
 988 };
 989
 990 static void xen_block_register_backend(void)
 991 {
 992     xen_backend_register(&xen_block_backend_info);
 993 }
 994
 995 xen_backend_init(xen_block_register_backend);