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