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 "hw/xen/xen_common.h"
  22 #include "hw/block/xen_blkif.h"
  23 #include "hw/qdev-properties.h"
  24 #include "hw/xen/xen-block.h"
  25 #include "hw/xen/xen-backend.h"
  26 #include "sysemu/blockdev.h"
  27 #include "sysemu/block-backend.h"
  28 #include "sysemu/iothread.h"
  29 #include "dataplane/xen-block.h"
  30 #include "trace.h"
  31
  32 static char *xen_block_get_name(XenDevice *xendev, Error **errp)
  33 {
  34     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  35     XenBlockVdev *vdev = &blockdev->props.vdev;
  36
  37     return g_strdup_printf("%lu", vdev->number);
  38 }
  39
  40 static void xen_block_disconnect(XenDevice *xendev, Error **errp)
  41 {
  42     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  43     const char *type = object_get_typename(OBJECT(blockdev));
  44     XenBlockVdev *vdev = &blockdev->props.vdev;
  45
  46     trace_xen_block_disconnect(type, vdev->disk, vdev->partition);
  47
  48     xen_block_dataplane_stop(blockdev->dataplane);
  49 }
  50
  51 static void xen_block_connect(XenDevice *xendev, Error **errp)
  52 {
  53     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  54     const char *type = object_get_typename(OBJECT(blockdev));
  55     XenBlockVdev *vdev = &blockdev->props.vdev;
  56     BlockConf *conf = &blockdev->props.conf;
  57     unsigned int feature_large_sector_size;
  58     unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol;
  59     char *str;
  60
  61     trace_xen_block_connect(type, vdev->disk, vdev->partition);
  62
  63     if (xen_device_frontend_scanf(xendev, "feature-large-sector-size", "%u",
  64                                   &feature_large_sector_size) != 1) {
  65         feature_large_sector_size = 0;
  66     }
  67
  68     if (feature_large_sector_size != 1 &&
  69         conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) {
  70         error_setg(errp, "logical_block_size != %u not supported by frontend",
  71                    XEN_BLKIF_SECTOR_SIZE);
  72         return;
  73     }
  74
  75     if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u",
  76                                   &order) != 1) {
  77         nr_ring_ref = 1;
  78         ring_ref = g_new(unsigned int, nr_ring_ref);
  79
  80         if (xen_device_frontend_scanf(xendev, "ring-ref", "%u",
  81                                       &ring_ref[0]) != 1) {
  82             error_setg(errp, "failed to read ring-ref");
  83             g_free(ring_ref);
  84             return;
  85         }
  86     } else if (order <= blockdev->props.max_ring_page_order) {
  87         unsigned int i;
  88
  89         nr_ring_ref = 1 << order;
  90         ring_ref = g_new(unsigned int, nr_ring_ref);
  91
  92         for (i = 0; i < nr_ring_ref; i++) {
  93             const char *key = g_strdup_printf("ring-ref%u", i);
  94
  95             if (xen_device_frontend_scanf(xendev, key, "%u",
  96                                           &ring_ref[i]) != 1) {
  97                 error_setg(errp, "failed to read %s", key);
  98                 g_free((gpointer)key);
  99                 g_free(ring_ref);
 100                 return;
 101             }
 102
 103             g_free((gpointer)key);
 104         }
 105     } else {
 106         error_setg(errp, "invalid ring-page-order (%d)", order);
 107         return;
 108     }
 109
 110     if (xen_device_frontend_scanf(xendev, "event-channel", "%u",
 111                                   &event_channel) != 1) {
 112         error_setg(errp, "failed to read event-channel");
 113         g_free(ring_ref);
 114         return;
 115     }
 116
 117     if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
 118                                   &str) != 1) {
 119         protocol = BLKIF_PROTOCOL_NATIVE;
 120     } else {
 121         if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
 122             protocol = BLKIF_PROTOCOL_X86_32;
 123         } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) {
 124             protocol = BLKIF_PROTOCOL_X86_64;
 125         } else {
 126             protocol = BLKIF_PROTOCOL_NATIVE;
 127         }
 128
 129         free(str);
 130     }
 131
 132     xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref,
 133                               event_channel, protocol, errp);
 134
 135     g_free(ring_ref);
 136 }
 137
 138 static void xen_block_unrealize(XenDevice *xendev, Error **errp)
 139 {
 140     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 141     XenBlockDeviceClass *blockdev_class =
 142         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 143     const char *type = object_get_typename(OBJECT(blockdev));
 144     XenBlockVdev *vdev = &blockdev->props.vdev;
 145
 146     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
 147         return;
 148     }
 149
 150     trace_xen_block_unrealize(type, vdev->disk, vdev->partition);
 151
 152     /* Disconnect from the frontend in case this has not already happened */
 153     xen_block_disconnect(xendev, NULL);
 154
 155     xen_block_dataplane_destroy(blockdev->dataplane);
 156     blockdev->dataplane = NULL;
 157
 158     if (blockdev_class->unrealize) {
 159         blockdev_class->unrealize(blockdev, errp);
 160     }
 161 }
 162
 163 static void xen_block_set_size(XenBlockDevice *blockdev)
 164 {
 165     const char *type = object_get_typename(OBJECT(blockdev));
 166     XenBlockVdev *vdev = &blockdev->props.vdev;
 167     BlockConf *conf = &blockdev->props.conf;
 168     int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size;
 169     XenDevice *xendev = XEN_DEVICE(blockdev);
 170
 171     trace_xen_block_size(type, vdev->disk, vdev->partition, sectors);
 172
 173     xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors);
 174 }
 175
 176 static void xen_block_resize_cb(void *opaque)
 177 {
 178     XenBlockDevice *blockdev = opaque;
 179     XenDevice *xendev = XEN_DEVICE(blockdev);
 180     enum xenbus_state state = xen_device_backend_get_state(xendev);
 181
 182     xen_block_set_size(blockdev);
 183
 184     /*
 185      * Mimic the behaviour of Linux xen-blkback and re-write the state
 186      * to trigger the frontend watch.
 187      */
 188     xen_device_backend_printf(xendev, "state", "%u", state);
 189 }
 190
 191 static const BlockDevOps xen_block_dev_ops = {
 192     .resize_cb = xen_block_resize_cb,
 193 };
 194
 195 static void xen_block_realize(XenDevice *xendev, Error **errp)
 196 {
 197     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 198     XenBlockDeviceClass *blockdev_class =
 199         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 200     const char *type = object_get_typename(OBJECT(blockdev));
 201     XenBlockVdev *vdev = &blockdev->props.vdev;
 202     BlockConf *conf = &blockdev->props.conf;
 203     BlockBackend *blk = conf->blk;
 204     Error *local_err = NULL;
 205
 206     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
 207         error_setg(errp, "vdev property not set");
 208         return;
 209     }
 210
 211     trace_xen_block_realize(type, vdev->disk, vdev->partition);
 212
 213     if (blockdev_class->realize) {
 214         blockdev_class->realize(blockdev, &local_err);
 215         if (local_err) {
 216             error_propagate(errp, local_err);
 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     blkconf_blocksizes(conf);
 242
 243     if (conf->logical_block_size > conf->physical_block_size) {
 244         error_setg(
 245             errp, "logical_block_size > physical_block_size not supported");
 246         return;
 247     }
 248
 249     blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev);
 250     blk_set_guest_block_size(blk, conf->logical_block_size);
 251
 252     if (conf->discard_granularity == -1) {
 253         conf->discard_granularity = conf->physical_block_size;
 254     }
 255
 256     if (blk_get_flags(blk) & BDRV_O_UNMAP) {
 257         xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
 258         xen_device_backend_printf(xendev, "discard-granularity", "%u",
 259                                   conf->discard_granularity);
 260     }
 261
 262     xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
 263     xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
 264                               blockdev->props.max_ring_page_order);
 265     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
 266
 267     xen_device_frontend_printf(xendev, "virtual-device", "%lu",
 268                                vdev->number);
 269     xen_device_frontend_printf(xendev, "device-type", "%s",
 270                                blockdev->device_type);
 271
 272     xen_device_backend_printf(xendev, "sector-size", "%u",
 273                               conf->logical_block_size);
 274
 275     xen_block_set_size(blockdev);
 276
 277     blockdev->dataplane =
 278         xen_block_dataplane_create(xendev, blk, conf->logical_block_size,
 279                                    blockdev->props.iothread);
 280 }
 281
 282 static void xen_block_frontend_changed(XenDevice *xendev,
 283                                        enum xenbus_state frontend_state,
 284                                        Error **errp)
 285 {
 286     enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
 287     Error *local_err = NULL;
 288
 289     switch (frontend_state) {
 290     case XenbusStateInitialised:
 291     case XenbusStateConnected:
 292         if (backend_state == XenbusStateConnected) {
 293             break;
 294         }
 295
 296         xen_block_disconnect(xendev, &local_err);
 297         if (local_err) {
 298             error_propagate(errp, local_err);
 299             break;
 300         }
 301
 302         xen_block_connect(xendev, &local_err);
 303         if (local_err) {
 304             error_propagate(errp, local_err);
 305             break;
 306         }
 307
 308         xen_device_backend_set_state(xendev, XenbusStateConnected);
 309         break;
 310
 311     case XenbusStateClosing:
 312         xen_device_backend_set_state(xendev, XenbusStateClosing);
 313         break;
 314
 315     case XenbusStateClosed:
 316         xen_block_disconnect(xendev, &local_err);
 317         if (local_err) {
 318             error_propagate(errp, local_err);
 319             break;
 320         }
 321
 322         xen_device_backend_set_state(xendev, XenbusStateClosed);
 323         break;
 324
 325     default:
 326         break;
 327     }
 328 }
 329
 330 static char *disk_to_vbd_name(unsigned int disk)
 331 {
 332     char *name, *prefix = (disk >= 26) ?
 333         disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
 334
 335     name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26);
 336     g_free(prefix);
 337
 338     return name;
 339 }
 340
 341 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
 342                                void *opaque, Error **errp)
 343 {
 344     DeviceState *dev = DEVICE(obj);
 345     Property *prop = opaque;
 346     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 347     char *str;
 348
 349     switch (vdev->type) {
 350     case XEN_BLOCK_VDEV_TYPE_DP:
 351         str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
 352         break;
 353
 354     case XEN_BLOCK_VDEV_TYPE_XVD:
 355     case XEN_BLOCK_VDEV_TYPE_HD:
 356     case XEN_BLOCK_VDEV_TYPE_SD: {
 357         char *name = disk_to_vbd_name(vdev->disk);
 358
 359         str = g_strdup_printf("%s%s%lu",
 360                               (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
 361                               "xvd" :
 362                               (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
 363                               "hd" :
 364                               "sd",
 365                               name, vdev->partition);
 366         g_free(name);
 367         break;
 368     }
 369     default:
 370         error_setg(errp, "invalid vdev type");
 371         return;
 372     }
 373
 374     visit_type_str(v, name, &str, errp);
 375     g_free(str);
 376 }
 377
 378 static int vbd_name_to_disk(const char *name, const char **endp,
 379                             unsigned long *disk)
 380 {
 381     unsigned int n = 0;
 382
 383     while (*name != '\0') {
 384         if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
 385             break;
 386         }
 387
 388         n *= 26;
 389         n += *name++ - 'a' + 1;
 390     }
 391     *endp = name;
 392
 393     if (!n) {
 394         return -1;
 395     }
 396
 397     *disk = n - 1;
 398
 399     return 0;
 400 }
 401
 402 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
 403                                void *opaque, Error **errp)
 404 {
 405     DeviceState *dev = DEVICE(obj);
 406     Property *prop = opaque;
 407     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 408     Error *local_err = NULL;
 409     char *str, *p;
 410     const char *end;
 411
 412     if (dev->realized) {
 413         qdev_prop_set_after_realize(dev, name, errp);
 414         return;
 415     }
 416
 417     visit_type_str(v, name, &str, &local_err);
 418     if (local_err) {
 419         error_propagate(errp, local_err);
 420         return;
 421     }
 422
 423     p = strchr(str, 'd');
 424     if (!p) {
 425         goto invalid;
 426     }
 427
 428     *p++ = '\0';
 429     if (*str == '\0') {
 430         vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
 431     } else if (strcmp(str, "xv") == 0) {
 432         vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
 433     } else if (strcmp(str, "h") == 0) {
 434         vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
 435     } else if (strcmp(str, "s") == 0) {
 436         vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
 437     } else {
 438         goto invalid;
 439     }
 440
 441     if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
 442         if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
 443             goto invalid;
 444         }
 445
 446         if (*end == 'p') {
 447             if (*(++end) == '\0') {
 448                 goto invalid;
 449             }
 450         }
 451     } else {
 452         if (vbd_name_to_disk(p, &end, &vdev->disk)) {
 453             goto invalid;
 454         }
 455     }
 456
 457     if (*end != '\0') {
 458         p = (char *)end;
 459
 460         if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
 461             goto invalid;
 462         }
 463
 464         if (*end != '\0') {
 465             goto invalid;
 466         }
 467     } else {
 468         vdev->partition = 0;
 469     }
 470
 471     switch (vdev->type) {
 472     case XEN_BLOCK_VDEV_TYPE_DP:
 473     case XEN_BLOCK_VDEV_TYPE_XVD:
 474         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 475             vdev->number = (202 << 8) | (vdev->disk << 4) |
 476                 vdev->partition;
 477         } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
 478             vdev->number = (1 << 28) | (vdev->disk << 8) |
 479                 vdev->partition;
 480         } else {
 481             goto invalid;
 482         }
 483         break;
 484
 485     case XEN_BLOCK_VDEV_TYPE_HD:
 486         if ((vdev->disk == 0 || vdev->disk == 1) &&
 487             vdev->partition < (1 << 6)) {
 488             vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
 489         } else if ((vdev->disk == 2 || vdev->disk == 3) &&
 490                    vdev->partition < (1 << 6)) {
 491             vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
 492                 vdev->partition;
 493         } else {
 494             goto invalid;
 495         }
 496         break;
 497
 498     case XEN_BLOCK_VDEV_TYPE_SD:
 499         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 500             vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
 501         } else {
 502             goto invalid;
 503         }
 504         break;
 505
 506     default:
 507         goto invalid;
 508     }
 509
 510     g_free(str);
 511     return;
 512
 513 invalid:
 514     error_setg(errp, "invalid virtual disk specifier");
 515
 516     vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
 517     g_free(str);
 518 }
 519
 520 /*
 521  * This property deals with 'vdev' names adhering to the Xen VBD naming
 522  * scheme described in:
 523  *
 524  * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
 525  */
 526 const PropertyInfo xen_block_prop_vdev = {
 527     .name  = "str",
 528     .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
 529     .get = xen_block_get_vdev,
 530     .set = xen_block_set_vdev,
 531 };
 532
 533 static Property xen_block_props[] = {
 534     DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
 535                 xen_block_prop_vdev, XenBlockVdev),
 536     DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
 537     DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
 538                        props.max_ring_page_order, 4),
 539     DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
 540                      TYPE_IOTHREAD, IOThread *),
 541     DEFINE_PROP_END_OF_LIST()
 542 };
 543
 544 static void xen_block_class_init(ObjectClass *class, void *data)
 545 {
 546     DeviceClass *dev_class = DEVICE_CLASS(class);
 547     XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
 548
 549     xendev_class->backend = "qdisk";
 550     xendev_class->device = "vbd";
 551     xendev_class->get_name = xen_block_get_name;
 552     xendev_class->realize = xen_block_realize;
 553     xendev_class->frontend_changed = xen_block_frontend_changed;
 554     xendev_class->unrealize = xen_block_unrealize;
 555
 556     dev_class->props = xen_block_props;
 557 }
 558
 559 static const TypeInfo xen_block_type_info = {
 560     .name = TYPE_XEN_BLOCK_DEVICE,
 561     .parent = TYPE_XEN_DEVICE,
 562     .instance_size = sizeof(XenBlockDevice),
 563     .abstract = true,
 564     .class_size = sizeof(XenBlockDeviceClass),
 565     .class_init = xen_block_class_init,
 566 };
 567
 568 static void xen_disk_unrealize(XenBlockDevice *blockdev, Error **errp)
 569 {
 570     trace_xen_disk_unrealize();
 571 }
 572
 573 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
 574 {
 575     BlockConf *conf = &blockdev->props.conf;
 576
 577     trace_xen_disk_realize();
 578
 579     blockdev->device_type = "disk";
 580
 581     if (!conf->blk) {
 582         error_setg(errp, "drive property not set");
 583         return;
 584     }
 585
 586     blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
 587 }
 588
 589 static void xen_disk_class_init(ObjectClass *class, void *data)
 590 {
 591     DeviceClass *dev_class = DEVICE_CLASS(class);
 592     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 593
 594     blockdev_class->realize = xen_disk_realize;
 595     blockdev_class->unrealize = xen_disk_unrealize;
 596
 597     dev_class->desc = "Xen Disk Device";
 598 }
 599
 600 static const TypeInfo xen_disk_type_info = {
 601     .name = TYPE_XEN_DISK_DEVICE,
 602     .parent = TYPE_XEN_BLOCK_DEVICE,
 603     .instance_size = sizeof(XenDiskDevice),
 604     .class_init = xen_disk_class_init,
 605 };
 606
 607 static void xen_cdrom_unrealize(XenBlockDevice *blockdev, Error **errp)
 608 {
 609     trace_xen_cdrom_unrealize();
 610 }
 611
 612 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
 613 {
 614     BlockConf *conf = &blockdev->props.conf;
 615
 616     trace_xen_cdrom_realize();
 617
 618     blockdev->device_type = "cdrom";
 619
 620     if (!conf->blk) {
 621         int rc;
 622
 623         /* Set up an empty drive */
 624         conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
 625
 626         rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
 627         if (!rc) {
 628             error_setg_errno(errp, -rc, "failed to create drive");
 629             return;
 630         }
 631     }
 632
 633     blockdev->info = VDISK_READONLY | VDISK_CDROM;
 634 }
 635
 636 static void xen_cdrom_class_init(ObjectClass *class, void *data)
 637 {
 638     DeviceClass *dev_class = DEVICE_CLASS(class);
 639     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 640
 641     blockdev_class->realize = xen_cdrom_realize;
 642     blockdev_class->unrealize = xen_cdrom_unrealize;
 643
 644     dev_class->desc = "Xen CD-ROM Device";
 645 }
 646
 647 static const TypeInfo xen_cdrom_type_info = {
 648     .name = TYPE_XEN_CDROM_DEVICE,
 649     .parent = TYPE_XEN_BLOCK_DEVICE,
 650     .instance_size = sizeof(XenCDRomDevice),
 651     .class_init = xen_cdrom_class_init,
 652 };
 653
 654 static void xen_block_register_types(void)
 655 {
 656     type_register_static(&xen_block_type_info);
 657     type_register_static(&xen_disk_type_info);
 658     type_register_static(&xen_cdrom_type_info);
 659 }
 660
 661 type_init(xen_block_register_types)
 662
 663 static void xen_block_blockdev_del(const char *node_name, Error **errp)
 664 {
 665     trace_xen_block_blockdev_del(node_name);
 666
 667     qmp_blockdev_del(node_name, errp);
 668 }
 669
 670 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
 671                                     Error **errp)
 672 {
 673     const char *driver = qdict_get_try_str(qdict, "driver");
 674     BlockdevOptions *options = NULL;
 675     Error *local_err = NULL;
 676     char *node_name;
 677     Visitor *v;
 678
 679     if (!driver) {
 680         error_setg(errp, "no 'driver' parameter");
 681         return NULL;
 682     }
 683
 684     node_name = g_strdup_printf("%s-%s", id, driver);
 685     qdict_put_str(qdict, "node-name", node_name);
 686
 687     trace_xen_block_blockdev_add(node_name);
 688
 689     v = qobject_input_visitor_new(QOBJECT(qdict));
 690     visit_type_BlockdevOptions(v, NULL, &options, &local_err);
 691     visit_free(v);
 692
 693     if (local_err) {
 694         error_propagate(errp, local_err);
 695         goto fail;
 696     }
 697
 698     qmp_blockdev_add(options, &local_err);
 699
 700     if (local_err) {
 701         error_propagate(errp, local_err);
 702         goto fail;
 703     }
 704
 705     qapi_free_BlockdevOptions(options);
 706
 707     return node_name;
 708
 709 fail:
 710     if (options) {
 711         qapi_free_BlockdevOptions(options);
 712     }
 713     g_free(node_name);
 714
 715     return NULL;
 716 }
 717
 718 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
 719 {
 720     char *node_name = drive->node_name;
 721
 722     if (node_name) {
 723         Error *local_err = NULL;
 724
 725         xen_block_blockdev_del(node_name, &local_err);
 726         if (local_err) {
 727             error_propagate(errp, local_err);
 728             return;
 729         }
 730         g_free(node_name);
 731         drive->node_name = NULL;
 732     }
 733     g_free(drive->id);
 734     g_free(drive);
 735 }
 736
 737 static XenBlockDrive *xen_block_drive_create(const char *id,
 738                                              const char *device_type,
 739                                              QDict *opts, Error **errp)
 740 {
 741     const char *params = qdict_get_try_str(opts, "params");
 742     const char *mode = qdict_get_try_str(opts, "mode");
 743     const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
 744     const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
 745     char *driver = NULL;
 746     char *filename = NULL;
 747     XenBlockDrive *drive = NULL;
 748     Error *local_err = NULL;
 749     QDict *file_layer;
 750     QDict *driver_layer;
 751
 752     if (params) {
 753         char **v = g_strsplit(params, ":", 2);
 754
 755         if (v[1] == NULL) {
 756             filename = g_strdup(v[0]);
 757             driver = g_strdup("raw");
 758         } else {
 759             if (strcmp(v[0], "aio") == 0) {
 760                 driver = g_strdup("raw");
 761             } else if (strcmp(v[0], "vhd") == 0) {
 762                 driver = g_strdup("vpc");
 763             } else {
 764                 driver = g_strdup(v[0]);
 765             }
 766             filename = g_strdup(v[1]);
 767         }
 768
 769         g_strfreev(v);
 770     } else {
 771         error_setg(errp, "no params");
 772         goto done;
 773     }
 774
 775     assert(filename);
 776     assert(driver);
 777
 778     drive = g_new0(XenBlockDrive, 1);
 779     drive->id = g_strdup(id);
 780
 781     file_layer = qdict_new();
 782     driver_layer = qdict_new();
 783
 784     qdict_put_str(file_layer, "driver", "file");
 785     qdict_put_str(file_layer, "filename", filename);
 786     g_free(filename);
 787
 788     if (mode && *mode != 'w') {
 789         qdict_put_bool(file_layer, "read-only", true);
 790     }
 791
 792     if (direct_io_safe) {
 793         unsigned long value;
 794
 795         if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
 796             QDict *cache_qdict = qdict_new();
 797
 798             qdict_put_bool(cache_qdict, "direct", true);
 799             qdict_put(file_layer, "cache", cache_qdict);
 800
 801             qdict_put_str(file_layer, "aio", "native");
 802         }
 803     }
 804
 805     if (discard_enable) {
 806         unsigned long value;
 807
 808         if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
 809             qdict_put_str(file_layer, "discard", "unmap");
 810             qdict_put_str(driver_layer, "discard", "unmap");
 811         }
 812     }
 813
 814     /*
 815      * It is necessary to turn file locking off as an emulated device
 816      * may have already opened the same image file.
 817      */
 818     qdict_put_str(file_layer, "locking", "off");
 819
 820     qdict_put_str(driver_layer, "driver", driver);
 821     g_free(driver);
 822
 823     qdict_put(driver_layer, "file", file_layer);
 824
 825     g_assert(!drive->node_name);
 826     drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
 827                                               &local_err);
 828
 829     qobject_unref(driver_layer);
 830
 831 done:
 832     if (local_err) {
 833         error_propagate(errp, local_err);
 834         xen_block_drive_destroy(drive, NULL);
 835         return NULL;
 836     }
 837
 838     return drive;
 839 }
 840
 841 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
 842 {
 843     return drive->node_name ? drive->node_name : "";
 844 }
 845
 846 static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
 847                                        Error **errp)
 848 {
 849     qmp_object_del(iothread->id, errp);
 850
 851     g_free(iothread->id);
 852     g_free(iothread);
 853 }
 854
 855 static XenBlockIOThread *xen_block_iothread_create(const char *id,
 856                                                    Error **errp)
 857 {
 858     XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
 859     Error *local_err = NULL;
 860
 861     iothread->id = g_strdup(id);
 862
 863     qmp_object_add(TYPE_IOTHREAD, id, false, NULL, &local_err);
 864     if (local_err) {
 865         error_propagate(errp, local_err);
 866
 867         g_free(iothread->id);
 868         g_free(iothread);
 869         return NULL;
 870     }
 871
 872     return iothread;
 873 }
 874
 875 static void xen_block_device_create(XenBackendInstance *backend,
 876                                     QDict *opts, Error **errp)
 877 {
 878     XenBus *xenbus = xen_backend_get_bus(backend);
 879     const char *name = xen_backend_get_name(backend);
 880     unsigned long number;
 881     const char *vdev, *device_type;
 882     XenBlockDrive *drive = NULL;
 883     XenBlockIOThread *iothread = NULL;
 884     XenDevice *xendev = NULL;
 885     Error *local_err = NULL;
 886     const char *type;
 887     XenBlockDevice *blockdev;
 888
 889     if (qemu_strtoul(name, NULL, 10, &number)) {
 890         error_setg(errp, "failed to parse name '%s'", name);
 891         goto fail;
 892     }
 893
 894     trace_xen_block_device_create(number);
 895
 896     vdev = qdict_get_try_str(opts, "dev");
 897     if (!vdev) {
 898         error_setg(errp, "no dev parameter");
 899         goto fail;
 900     }
 901
 902     device_type = qdict_get_try_str(opts, "device-type");
 903     if (!device_type) {
 904         error_setg(errp, "no device-type parameter");
 905         goto fail;
 906     }
 907
 908     if (!strcmp(device_type, "disk")) {
 909         type = TYPE_XEN_DISK_DEVICE;
 910     } else if (!strcmp(device_type, "cdrom")) {
 911         type = TYPE_XEN_CDROM_DEVICE;
 912     } else {
 913         error_setg(errp, "invalid device-type parameter '%s'", device_type);
 914         goto fail;
 915     }
 916
 917     drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
 918     if (!drive) {
 919         error_propagate_prepend(errp, local_err, "failed to create drive: ");
 920         goto fail;
 921     }
 922
 923     iothread = xen_block_iothread_create(vdev, &local_err);
 924     if (local_err) {
 925         error_propagate_prepend(errp, local_err,
 926                                 "failed to create iothread: ");
 927         goto fail;
 928     }
 929
 930     xendev = XEN_DEVICE(qdev_create(BUS(xenbus), type));
 931     blockdev = XEN_BLOCK_DEVICE(xendev);
 932
 933     object_property_set_str(OBJECT(xendev), vdev, "vdev", &local_err);
 934     if (local_err) {
 935         error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
 936         goto fail;
 937     }
 938
 939     object_property_set_str(OBJECT(xendev),
 940                             xen_block_drive_get_node_name(drive), "drive",
 941                             &local_err);
 942     if (local_err) {
 943         error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
 944         goto fail;
 945     }
 946
 947     object_property_set_str(OBJECT(xendev), iothread->id, "iothread",
 948                             &local_err);
 949     if (local_err) {
 950         error_propagate_prepend(errp, local_err,
 951                                 "failed to set 'iothread': ");
 952         goto fail;
 953     }
 954
 955     blockdev->iothread = iothread;
 956     blockdev->drive = drive;
 957
 958     object_property_set_bool(OBJECT(xendev), true, "realized", &local_err);
 959     if (local_err) {
 960         error_propagate_prepend(errp, local_err,
 961                                 "realization of device %s failed: ",
 962                                 type);
 963         goto fail;
 964     }
 965
 966     xen_backend_set_device(backend, xendev);
 967     return;
 968
 969 fail:
 970     if (xendev) {
 971         object_unparent(OBJECT(xendev));
 972     }
 973
 974     if (iothread) {
 975         xen_block_iothread_destroy(iothread, NULL);
 976     }
 977
 978     if (drive) {
 979         xen_block_drive_destroy(drive, NULL);
 980     }
 981 }
 982
 983 static void xen_block_device_destroy(XenBackendInstance *backend,
 984                                      Error **errp)
 985 {
 986     XenDevice *xendev = xen_backend_get_device(backend);
 987     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 988     XenBlockVdev *vdev = &blockdev->props.vdev;
 989     XenBlockDrive *drive = blockdev->drive;
 990     XenBlockIOThread *iothread = blockdev->iothread;
 991
 992     trace_xen_block_device_destroy(vdev->number);
 993
 994     object_unparent(OBJECT(xendev));
 995
 996     if (iothread) {
 997         Error *local_err = NULL;
 998
 999         xen_block_iothread_destroy(iothread, &local_err);
1000         if (local_err) {
1001             error_propagate_prepend(errp, local_err,
1002                                 "failed to destroy iothread: ");
1003             return;
1004         }
1005     }
1006
1007     if (drive) {
1008         Error *local_err = NULL;
1009
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         }
1015     }
1016 }
1017
1018 static const XenBackendInfo xen_block_backend_info = {
1019     .type = "qdisk",
1020     .create = xen_block_device_create,
1021     .destroy = xen_block_device_destroy,
1022 };
1023
1024 static void xen_block_register_backend(void)
1025 {
1026     xen_backend_register(&xen_block_backend_info);
1027 }
1028
1029 xen_backend_init(xen_block_register_backend);