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     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 199     XenBlockDeviceClass *blockdev_class =
 200         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 201     const char *type = object_get_typename(OBJECT(blockdev));
 202     XenBlockVdev *vdev = &blockdev->props.vdev;
 203     BlockConf *conf = &blockdev->props.conf;
 204     BlockBackend *blk = conf->blk;
 205     Error *local_err = NULL;
 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, &local_err);
 216         if (local_err) {
 217             error_propagate(errp, local_err);
 218             return;
 219         }
 220     }
 221
 222     /*
 223      * The blkif protocol does not deal with removable media, so it must
 224      * always be present, even for CDRom devices.
 225      */
 226     assert(blk);
 227     if (!blk_is_inserted(blk)) {
 228         error_setg(errp, "device needs media, but drive is empty");
 229         return;
 230     }
 231
 232     if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
 233                                        true, errp)) {
 234         return;
 235     }
 236
 237     if (!(blockdev->info & VDISK_CDROM) &&
 238         !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) {
 239         return;
 240     }
 241
 242     if (!blkconf_blocksizes(conf, errp)) {
 243         return;
 244     }
 245
 246     blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev);
 247     blk_set_guest_block_size(blk, conf->logical_block_size);
 248
 249     if (conf->discard_granularity == -1) {
 250         conf->discard_granularity = conf->physical_block_size;
 251     }
 252
 253     if (blk_get_flags(blk) & BDRV_O_UNMAP) {
 254         xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
 255         xen_device_backend_printf(xendev, "discard-granularity", "%u",
 256                                   conf->discard_granularity);
 257     }
 258
 259     xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
 260     xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
 261                               blockdev->props.max_ring_page_order);
 262     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
 263
 264     xen_device_frontend_printf(xendev, "virtual-device", "%lu",
 265                                vdev->number);
 266     xen_device_frontend_printf(xendev, "device-type", "%s",
 267                                blockdev->device_type);
 268
 269     xen_device_backend_printf(xendev, "sector-size", "%u",
 270                               conf->logical_block_size);
 271
 272     xen_block_set_size(blockdev);
 273
 274     blockdev->dataplane =
 275         xen_block_dataplane_create(xendev, blk, conf->logical_block_size,
 276                                    blockdev->props.iothread);
 277 }
 278
 279 static void xen_block_frontend_changed(XenDevice *xendev,
 280                                        enum xenbus_state frontend_state,
 281                                        Error **errp)
 282 {
 283     enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
 284     Error *local_err = NULL;
 285
 286     switch (frontend_state) {
 287     case XenbusStateInitialised:
 288     case XenbusStateConnected:
 289         if (backend_state == XenbusStateConnected) {
 290             break;
 291         }
 292
 293         xen_block_disconnect(xendev, &local_err);
 294         if (local_err) {
 295             error_propagate(errp, local_err);
 296             break;
 297         }
 298
 299         xen_block_connect(xendev, &local_err);
 300         if (local_err) {
 301             error_propagate(errp, local_err);
 302             break;
 303         }
 304
 305         xen_device_backend_set_state(xendev, XenbusStateConnected);
 306         break;
 307
 308     case XenbusStateClosing:
 309         xen_device_backend_set_state(xendev, XenbusStateClosing);
 310         break;
 311
 312     case XenbusStateClosed:
 313     case XenbusStateUnknown:
 314         xen_block_disconnect(xendev, &local_err);
 315         if (local_err) {
 316             error_propagate(errp, local_err);
 317             break;
 318         }
 319
 320         xen_device_backend_set_state(xendev, XenbusStateClosed);
 321         break;
 322
 323     default:
 324         break;
 325     }
 326 }
 327
 328 static char *disk_to_vbd_name(unsigned int disk)
 329 {
 330     char *name, *prefix = (disk >= 26) ?
 331         disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
 332
 333     name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26);
 334     g_free(prefix);
 335
 336     return name;
 337 }
 338
 339 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
 340                                void *opaque, Error **errp)
 341 {
 342     DeviceState *dev = DEVICE(obj);
 343     Property *prop = opaque;
 344     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 345     char *str;
 346
 347     switch (vdev->type) {
 348     case XEN_BLOCK_VDEV_TYPE_DP:
 349         str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
 350         break;
 351
 352     case XEN_BLOCK_VDEV_TYPE_XVD:
 353     case XEN_BLOCK_VDEV_TYPE_HD:
 354     case XEN_BLOCK_VDEV_TYPE_SD: {
 355         char *name = disk_to_vbd_name(vdev->disk);
 356
 357         str = g_strdup_printf("%s%s%lu",
 358                               (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
 359                               "xvd" :
 360                               (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
 361                               "hd" :
 362                               "sd",
 363                               name, vdev->partition);
 364         g_free(name);
 365         break;
 366     }
 367     default:
 368         error_setg(errp, "invalid vdev type");
 369         return;
 370     }
 371
 372     visit_type_str(v, name, &str, errp);
 373     g_free(str);
 374 }
 375
 376 static int vbd_name_to_disk(const char *name, const char **endp,
 377                             unsigned long *disk)
 378 {
 379     unsigned int n = 0;
 380
 381     while (*name != '\0') {
 382         if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
 383             break;
 384         }
 385
 386         n *= 26;
 387         n += *name++ - 'a' + 1;
 388     }
 389     *endp = name;
 390
 391     if (!n) {
 392         return -1;
 393     }
 394
 395     *disk = n - 1;
 396
 397     return 0;
 398 }
 399
 400 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
 401                                void *opaque, Error **errp)
 402 {
 403     DeviceState *dev = DEVICE(obj);
 404     Property *prop = opaque;
 405     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 406     Error *local_err = NULL;
 407     char *str, *p;
 408     const char *end;
 409
 410     if (dev->realized) {
 411         qdev_prop_set_after_realize(dev, name, errp);
 412         return;
 413     }
 414
 415     if (!visit_type_str(v, name, &str, &local_err)) {
 416         error_propagate(errp, local_err);
 417         return;
 418     }
 419
 420     p = strchr(str, 'd');
 421     if (!p) {
 422         goto invalid;
 423     }
 424
 425     *p++ = '\0';
 426     if (*str == '\0') {
 427         vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
 428     } else if (strcmp(str, "xv") == 0) {
 429         vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
 430     } else if (strcmp(str, "h") == 0) {
 431         vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
 432     } else if (strcmp(str, "s") == 0) {
 433         vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
 434     } else {
 435         goto invalid;
 436     }
 437
 438     if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
 439         if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
 440             goto invalid;
 441         }
 442
 443         if (*end == 'p') {
 444             if (*(++end) == '\0') {
 445                 goto invalid;
 446             }
 447         }
 448     } else {
 449         if (vbd_name_to_disk(p, &end, &vdev->disk)) {
 450             goto invalid;
 451         }
 452     }
 453
 454     if (*end != '\0') {
 455         p = (char *)end;
 456
 457         if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
 458             goto invalid;
 459         }
 460
 461         if (*end != '\0') {
 462             goto invalid;
 463         }
 464     } else {
 465         vdev->partition = 0;
 466     }
 467
 468     switch (vdev->type) {
 469     case XEN_BLOCK_VDEV_TYPE_DP:
 470     case XEN_BLOCK_VDEV_TYPE_XVD:
 471         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 472             vdev->number = (202 << 8) | (vdev->disk << 4) |
 473                 vdev->partition;
 474         } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
 475             vdev->number = (1 << 28) | (vdev->disk << 8) |
 476                 vdev->partition;
 477         } else {
 478             goto invalid;
 479         }
 480         break;
 481
 482     case XEN_BLOCK_VDEV_TYPE_HD:
 483         if ((vdev->disk == 0 || vdev->disk == 1) &&
 484             vdev->partition < (1 << 6)) {
 485             vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
 486         } else if ((vdev->disk == 2 || vdev->disk == 3) &&
 487                    vdev->partition < (1 << 6)) {
 488             vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
 489                 vdev->partition;
 490         } else {
 491             goto invalid;
 492         }
 493         break;
 494
 495     case XEN_BLOCK_VDEV_TYPE_SD:
 496         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 497             vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
 498         } else {
 499             goto invalid;
 500         }
 501         break;
 502
 503     default:
 504         goto invalid;
 505     }
 506
 507     g_free(str);
 508     return;
 509
 510 invalid:
 511     error_setg(errp, "invalid virtual disk specifier");
 512
 513     vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
 514     g_free(str);
 515 }
 516
 517 /*
 518  * This property deals with 'vdev' names adhering to the Xen VBD naming
 519  * scheme described in:
 520  *
 521  * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
 522  */
 523 const PropertyInfo xen_block_prop_vdev = {
 524     .name  = "str",
 525     .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
 526     .get = xen_block_get_vdev,
 527     .set = xen_block_set_vdev,
 528 };
 529
 530 static Property xen_block_props[] = {
 531     DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
 532                 xen_block_prop_vdev, XenBlockVdev),
 533     DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
 534     DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
 535                        props.max_ring_page_order, 4),
 536     DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
 537                      TYPE_IOTHREAD, IOThread *),
 538     DEFINE_PROP_END_OF_LIST()
 539 };
 540
 541 static void xen_block_class_init(ObjectClass *class, void *data)
 542 {
 543     DeviceClass *dev_class = DEVICE_CLASS(class);
 544     XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
 545
 546     xendev_class->backend = "qdisk";
 547     xendev_class->device = "vbd";
 548     xendev_class->get_name = xen_block_get_name;
 549     xendev_class->realize = xen_block_realize;
 550     xendev_class->frontend_changed = xen_block_frontend_changed;
 551     xendev_class->unrealize = xen_block_unrealize;
 552
 553     device_class_set_props(dev_class, xen_block_props);
 554 }
 555
 556 static const TypeInfo xen_block_type_info = {
 557     .name = TYPE_XEN_BLOCK_DEVICE,
 558     .parent = TYPE_XEN_DEVICE,
 559     .instance_size = sizeof(XenBlockDevice),
 560     .abstract = true,
 561     .class_size = sizeof(XenBlockDeviceClass),
 562     .class_init = xen_block_class_init,
 563 };
 564
 565 static void xen_disk_unrealize(XenBlockDevice *blockdev)
 566 {
 567     trace_xen_disk_unrealize();
 568 }
 569
 570 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
 571 {
 572     BlockConf *conf = &blockdev->props.conf;
 573
 574     trace_xen_disk_realize();
 575
 576     blockdev->device_type = "disk";
 577
 578     if (!conf->blk) {
 579         error_setg(errp, "drive property not set");
 580         return;
 581     }
 582
 583     blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
 584 }
 585
 586 static void xen_disk_class_init(ObjectClass *class, void *data)
 587 {
 588     DeviceClass *dev_class = DEVICE_CLASS(class);
 589     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 590
 591     blockdev_class->realize = xen_disk_realize;
 592     blockdev_class->unrealize = xen_disk_unrealize;
 593
 594     dev_class->desc = "Xen Disk Device";
 595 }
 596
 597 static const TypeInfo xen_disk_type_info = {
 598     .name = TYPE_XEN_DISK_DEVICE,
 599     .parent = TYPE_XEN_BLOCK_DEVICE,
 600     .instance_size = sizeof(XenDiskDevice),
 601     .class_init = xen_disk_class_init,
 602 };
 603
 604 static void xen_cdrom_unrealize(XenBlockDevice *blockdev)
 605 {
 606     trace_xen_cdrom_unrealize();
 607 }
 608
 609 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
 610 {
 611     BlockConf *conf = &blockdev->props.conf;
 612
 613     trace_xen_cdrom_realize();
 614
 615     blockdev->device_type = "cdrom";
 616
 617     if (!conf->blk) {
 618         int rc;
 619
 620         /* Set up an empty drive */
 621         conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
 622
 623         rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
 624         if (!rc) {
 625             error_setg_errno(errp, -rc, "failed to create drive");
 626             return;
 627         }
 628     }
 629
 630     blockdev->info = VDISK_READONLY | VDISK_CDROM;
 631 }
 632
 633 static void xen_cdrom_class_init(ObjectClass *class, void *data)
 634 {
 635     DeviceClass *dev_class = DEVICE_CLASS(class);
 636     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 637
 638     blockdev_class->realize = xen_cdrom_realize;
 639     blockdev_class->unrealize = xen_cdrom_unrealize;
 640
 641     dev_class->desc = "Xen CD-ROM Device";
 642 }
 643
 644 static const TypeInfo xen_cdrom_type_info = {
 645     .name = TYPE_XEN_CDROM_DEVICE,
 646     .parent = TYPE_XEN_BLOCK_DEVICE,
 647     .instance_size = sizeof(XenCDRomDevice),
 648     .class_init = xen_cdrom_class_init,
 649 };
 650
 651 static void xen_block_register_types(void)
 652 {
 653     type_register_static(&xen_block_type_info);
 654     type_register_static(&xen_disk_type_info);
 655     type_register_static(&xen_cdrom_type_info);
 656 }
 657
 658 type_init(xen_block_register_types)
 659
 660 static void xen_block_blockdev_del(const char *node_name, Error **errp)
 661 {
 662     trace_xen_block_blockdev_del(node_name);
 663
 664     qmp_blockdev_del(node_name, errp);
 665 }
 666
 667 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
 668                                     Error **errp)
 669 {
 670     const char *driver = qdict_get_try_str(qdict, "driver");
 671     BlockdevOptions *options = NULL;
 672     Error *local_err = NULL;
 673     char *node_name;
 674     Visitor *v;
 675
 676     if (!driver) {
 677         error_setg(errp, "no 'driver' parameter");
 678         return NULL;
 679     }
 680
 681     node_name = g_strdup_printf("%s-%s", id, driver);
 682     qdict_put_str(qdict, "node-name", node_name);
 683
 684     trace_xen_block_blockdev_add(node_name);
 685
 686     v = qobject_input_visitor_new(QOBJECT(qdict));
 687     visit_type_BlockdevOptions(v, NULL, &options, &local_err);
 688     visit_free(v);
 689
 690     if (local_err) {
 691         error_propagate(errp, local_err);
 692         goto fail;
 693     }
 694
 695     qmp_blockdev_add(options, &local_err);
 696
 697     if (local_err) {
 698         error_propagate(errp, local_err);
 699         goto fail;
 700     }
 701
 702     qapi_free_BlockdevOptions(options);
 703
 704     return node_name;
 705
 706 fail:
 707     if (options) {
 708         qapi_free_BlockdevOptions(options);
 709     }
 710     g_free(node_name);
 711
 712     return NULL;
 713 }
 714
 715 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
 716 {
 717     char *node_name = drive->node_name;
 718
 719     if (node_name) {
 720         Error *local_err = NULL;
 721
 722         xen_block_blockdev_del(node_name, &local_err);
 723         if (local_err) {
 724             error_propagate(errp, local_err);
 725             return;
 726         }
 727         g_free(node_name);
 728         drive->node_name = NULL;
 729     }
 730     g_free(drive->id);
 731     g_free(drive);
 732 }
 733
 734 static XenBlockDrive *xen_block_drive_create(const char *id,
 735                                              const char *device_type,
 736                                              QDict *opts, Error **errp)
 737 {
 738     const char *params = qdict_get_try_str(opts, "params");
 739     const char *mode = qdict_get_try_str(opts, "mode");
 740     const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
 741     const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
 742     char *driver = NULL;
 743     char *filename = NULL;
 744     XenBlockDrive *drive = NULL;
 745     Error *local_err = NULL;
 746     QDict *file_layer;
 747     QDict *driver_layer;
 748
 749     if (params) {
 750         char **v = g_strsplit(params, ":", 2);
 751
 752         if (v[1] == NULL) {
 753             filename = g_strdup(v[0]);
 754             driver = g_strdup("raw");
 755         } else {
 756             if (strcmp(v[0], "aio") == 0) {
 757                 driver = g_strdup("raw");
 758             } else if (strcmp(v[0], "vhd") == 0) {
 759                 driver = g_strdup("vpc");
 760             } else {
 761                 driver = g_strdup(v[0]);
 762             }
 763             filename = g_strdup(v[1]);
 764         }
 765
 766         g_strfreev(v);
 767     } else {
 768         error_setg(errp, "no params");
 769         goto done;
 770     }
 771
 772     assert(filename);
 773     assert(driver);
 774
 775     drive = g_new0(XenBlockDrive, 1);
 776     drive->id = g_strdup(id);
 777
 778     file_layer = qdict_new();
 779     driver_layer = qdict_new();
 780
 781     qdict_put_str(file_layer, "driver", "file");
 782     qdict_put_str(file_layer, "filename", filename);
 783     g_free(filename);
 784
 785     if (mode && *mode != 'w') {
 786         qdict_put_bool(file_layer, "read-only", true);
 787     }
 788
 789     if (direct_io_safe) {
 790         unsigned long value;
 791
 792         if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
 793             QDict *cache_qdict = qdict_new();
 794
 795             qdict_put_bool(cache_qdict, "direct", true);
 796             qdict_put(file_layer, "cache", cache_qdict);
 797
 798             qdict_put_str(file_layer, "aio", "native");
 799         }
 800     }
 801
 802     if (discard_enable) {
 803         unsigned long value;
 804
 805         if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
 806             qdict_put_str(file_layer, "discard", "unmap");
 807             qdict_put_str(driver_layer, "discard", "unmap");
 808         }
 809     }
 810
 811     /*
 812      * It is necessary to turn file locking off as an emulated device
 813      * may have already opened the same image file.
 814      */
 815     qdict_put_str(file_layer, "locking", "off");
 816
 817     qdict_put_str(driver_layer, "driver", driver);
 818     g_free(driver);
 819
 820     qdict_put(driver_layer, "file", file_layer);
 821
 822     g_assert(!drive->node_name);
 823     drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
 824                                               &local_err);
 825
 826     qobject_unref(driver_layer);
 827
 828 done:
 829     if (local_err) {
 830         error_propagate(errp, local_err);
 831         xen_block_drive_destroy(drive, NULL);
 832         return NULL;
 833     }
 834
 835     return drive;
 836 }
 837
 838 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
 839 {
 840     return drive->node_name ? drive->node_name : "";
 841 }
 842
 843 static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
 844                                        Error **errp)
 845 {
 846     qmp_object_del(iothread->id, errp);
 847
 848     g_free(iothread->id);
 849     g_free(iothread);
 850 }
 851
 852 static XenBlockIOThread *xen_block_iothread_create(const char *id,
 853                                                    Error **errp)
 854 {
 855     XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
 856     Error *local_err = NULL;
 857     QDict *opts;
 858     QObject *ret_data = NULL;
 859
 860     iothread->id = g_strdup(id);
 861
 862     opts = qdict_new();
 863     qdict_put_str(opts, "qom-type", TYPE_IOTHREAD);
 864     qdict_put_str(opts, "id", id);
 865     qmp_object_add(opts, &ret_data, &local_err);
 866     qobject_unref(opts);
 867     qobject_unref(ret_data);
 868
 869     if (local_err) {
 870         error_propagate(errp, local_err);
 871
 872         g_free(iothread->id);
 873         g_free(iothread);
 874         return NULL;
 875     }
 876
 877     return iothread;
 878 }
 879
 880 static void xen_block_device_create(XenBackendInstance *backend,
 881                                     QDict *opts, Error **errp)
 882 {
 883     XenBus *xenbus = xen_backend_get_bus(backend);
 884     const char *name = xen_backend_get_name(backend);
 885     unsigned long number;
 886     const char *vdev, *device_type;
 887     XenBlockDrive *drive = NULL;
 888     XenBlockIOThread *iothread = NULL;
 889     XenDevice *xendev = NULL;
 890     Error *local_err = NULL;
 891     const char *type;
 892     XenBlockDevice *blockdev;
 893
 894     if (qemu_strtoul(name, NULL, 10, &number)) {
 895         error_setg(errp, "failed to parse name '%s'", name);
 896         goto fail;
 897     }
 898
 899     trace_xen_block_device_create(number);
 900
 901     vdev = qdict_get_try_str(opts, "dev");
 902     if (!vdev) {
 903         error_setg(errp, "no dev parameter");
 904         goto fail;
 905     }
 906
 907     device_type = qdict_get_try_str(opts, "device-type");
 908     if (!device_type) {
 909         error_setg(errp, "no device-type parameter");
 910         goto fail;
 911     }
 912
 913     if (!strcmp(device_type, "disk")) {
 914         type = TYPE_XEN_DISK_DEVICE;
 915     } else if (!strcmp(device_type, "cdrom")) {
 916         type = TYPE_XEN_CDROM_DEVICE;
 917     } else {
 918         error_setg(errp, "invalid device-type parameter '%s'", device_type);
 919         goto fail;
 920     }
 921
 922     drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
 923     if (!drive) {
 924         error_propagate_prepend(errp, local_err, "failed to create drive: ");
 925         goto fail;
 926     }
 927
 928     iothread = xen_block_iothread_create(vdev, &local_err);
 929     if (local_err) {
 930         error_propagate_prepend(errp, local_err,
 931                                 "failed to create iothread: ");
 932         goto fail;
 933     }
 934
 935     xendev = XEN_DEVICE(qdev_new(type));
 936     blockdev = XEN_BLOCK_DEVICE(xendev);
 937
 938     object_property_set_str(OBJECT(xendev), "vdev", vdev, &local_err);
 939     if (local_err) {
 940         error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
 941         goto fail;
 942     }
 943
 944     object_property_set_str(OBJECT(xendev), "drive",
 945                             xen_block_drive_get_node_name(drive), &local_err);
 946     if (local_err) {
 947         error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
 948         goto fail;
 949     }
 950
 951     object_property_set_str(OBJECT(xendev), "iothread", iothread->id,
 952                             &local_err);
 953     if (local_err) {
 954         error_propagate_prepend(errp, local_err,
 955                                 "failed to set 'iothread': ");
 956         goto fail;
 957     }
 958
 959     blockdev->iothread = iothread;
 960     blockdev->drive = drive;
 961
 962     if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), &local_err)) {
 963         error_propagate_prepend(errp, local_err,
 964                                 "realization of device %s failed: ",
 965                                 type);
 966         goto fail;
 967     }
 968
 969     xen_backend_set_device(backend, xendev);
 970     return;
 971
 972 fail:
 973     if (xendev) {
 974         object_unparent(OBJECT(xendev));
 975     }
 976
 977     if (iothread) {
 978         xen_block_iothread_destroy(iothread, NULL);
 979     }
 980
 981     if (drive) {
 982         xen_block_drive_destroy(drive, NULL);
 983     }
 984 }
 985
 986 static void xen_block_device_destroy(XenBackendInstance *backend,
 987                                      Error **errp)
 988 {
 989     XenDevice *xendev = xen_backend_get_device(backend);
 990     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 991     XenBlockVdev *vdev = &blockdev->props.vdev;
 992     XenBlockDrive *drive = blockdev->drive;
 993     XenBlockIOThread *iothread = blockdev->iothread;
 994     Error *local_err = NULL;
 995
 996     trace_xen_block_device_destroy(vdev->number);
 997
 998     object_unparent(OBJECT(xendev));
 999
1000     if (iothread) {
1001         xen_block_iothread_destroy(iothread, &local_err);
1002         if (local_err) {
1003             error_propagate_prepend(errp, local_err,
1004                                     "failed to destroy iothread: ");
1005             return;
1006         }
1007     }
1008
1009     if (drive) {
1010         xen_block_drive_destroy(drive, &local_err);
1011         if (local_err) {
1012             error_propagate_prepend(errp, local_err,
1013                                     "failed to destroy drive: ");
1014             return;
1015         }
1016     }
1017 }
1018
1019 static const XenBackendInfo xen_block_backend_info = {
1020     .type = "qdisk",
1021     .create = xen_block_device_create,
1022     .destroy = xen_block_device_destroy,
1023 };
1024
1025 static void xen_block_register_backend(void)
1026 {
1027     xen_backend_register(&xen_block_backend_info);
1028 }
1029
1030 xen_backend_init(xen_block_register_backend);