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/xen/xen-block.h"
  24 #include "hw/xen/xen-backend.h"
  25 #include "sysemu/blockdev.h"
  26 #include "sysemu/block-backend.h"
  27 #include "sysemu/iothread.h"
  28 #include "dataplane/xen-block.h"
  29 #include "trace.h"
  30
  31 static char *xen_block_get_name(XenDevice *xendev, Error **errp)
  32 {
  33     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  34     XenBlockVdev *vdev = &blockdev->props.vdev;
  35
  36     return g_strdup_printf("%lu", vdev->number);
  37 }
  38
  39 static void xen_block_disconnect(XenDevice *xendev, Error **errp)
  40 {
  41     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  42     const char *type = object_get_typename(OBJECT(blockdev));
  43     XenBlockVdev *vdev = &blockdev->props.vdev;
  44
  45     trace_xen_block_disconnect(type, vdev->disk, vdev->partition);
  46
  47     xen_block_dataplane_stop(blockdev->dataplane);
  48 }
  49
  50 static void xen_block_connect(XenDevice *xendev, Error **errp)
  51 {
  52     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
  53     const char *type = object_get_typename(OBJECT(blockdev));
  54     XenBlockVdev *vdev = &blockdev->props.vdev;
  55     BlockConf *conf = &blockdev->props.conf;
  56     unsigned int feature_large_sector_size;
  57     unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol;
  58     char *str;
  59
  60     trace_xen_block_connect(type, vdev->disk, vdev->partition);
  61
  62     if (xen_device_frontend_scanf(xendev, "feature-large-sector-size", "%u",
  63                                   &feature_large_sector_size) != 1) {
  64         feature_large_sector_size = 0;
  65     }
  66
  67     if (feature_large_sector_size != 1 &&
  68         conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) {
  69         error_setg(errp, "logical_block_size != %u not supported by frontend",
  70                    XEN_BLKIF_SECTOR_SIZE);
  71         return;
  72     }
  73
  74     if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u",
  75                                   &order) != 1) {
  76         nr_ring_ref = 1;
  77         ring_ref = g_new(unsigned int, nr_ring_ref);
  78
  79         if (xen_device_frontend_scanf(xendev, "ring-ref", "%u",
  80                                       &ring_ref[0]) != 1) {
  81             error_setg(errp, "failed to read ring-ref");
  82             g_free(ring_ref);
  83             return;
  84         }
  85     } else if (order <= blockdev->props.max_ring_page_order) {
  86         unsigned int i;
  87
  88         nr_ring_ref = 1 << order;
  89         ring_ref = g_new(unsigned int, nr_ring_ref);
  90
  91         for (i = 0; i < nr_ring_ref; i++) {
  92             const char *key = g_strdup_printf("ring-ref%u", i);
  93
  94             if (xen_device_frontend_scanf(xendev, key, "%u",
  95                                           &ring_ref[i]) != 1) {
  96                 error_setg(errp, "failed to read %s", key);
  97                 g_free((gpointer)key);
  98                 g_free(ring_ref);
  99                 return;
 100             }
 101
 102             g_free((gpointer)key);
 103         }
 104     } else {
 105         error_setg(errp, "invalid ring-page-order (%d)", order);
 106         return;
 107     }
 108
 109     if (xen_device_frontend_scanf(xendev, "event-channel", "%u",
 110                                   &event_channel) != 1) {
 111         error_setg(errp, "failed to read event-channel");
 112         g_free(ring_ref);
 113         return;
 114     }
 115
 116     if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
 117                                   &str) != 1) {
 118         protocol = BLKIF_PROTOCOL_NATIVE;
 119     } else {
 120         if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
 121             protocol = BLKIF_PROTOCOL_X86_32;
 122         } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) {
 123             protocol = BLKIF_PROTOCOL_X86_64;
 124         } else {
 125             protocol = BLKIF_PROTOCOL_NATIVE;
 126         }
 127
 128         free(str);
 129     }
 130
 131     xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref,
 132                               event_channel, protocol, errp);
 133
 134     g_free(ring_ref);
 135 }
 136
 137 static void xen_block_unrealize(XenDevice *xendev, Error **errp)
 138 {
 139     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 140     XenBlockDeviceClass *blockdev_class =
 141         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 142     const char *type = object_get_typename(OBJECT(blockdev));
 143     XenBlockVdev *vdev = &blockdev->props.vdev;
 144
 145     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
 146         return;
 147     }
 148
 149     trace_xen_block_unrealize(type, vdev->disk, vdev->partition);
 150
 151     /* Disconnect from the frontend in case this has not already happened */
 152     xen_block_disconnect(xendev, NULL);
 153
 154     xen_block_dataplane_destroy(blockdev->dataplane);
 155     blockdev->dataplane = NULL;
 156
 157     if (blockdev_class->unrealize) {
 158         blockdev_class->unrealize(blockdev, errp);
 159     }
 160 }
 161
 162 static void xen_block_set_size(XenBlockDevice *blockdev)
 163 {
 164     const char *type = object_get_typename(OBJECT(blockdev));
 165     XenBlockVdev *vdev = &blockdev->props.vdev;
 166     BlockConf *conf = &blockdev->props.conf;
 167     int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size;
 168     XenDevice *xendev = XEN_DEVICE(blockdev);
 169
 170     trace_xen_block_size(type, vdev->disk, vdev->partition, sectors);
 171
 172     xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors);
 173 }
 174
 175 static void xen_block_resize_cb(void *opaque)
 176 {
 177     XenBlockDevice *blockdev = opaque;
 178     XenDevice *xendev = XEN_DEVICE(blockdev);
 179     enum xenbus_state state = xen_device_backend_get_state(xendev);
 180
 181     xen_block_set_size(blockdev);
 182
 183     /*
 184      * Mimic the behaviour of Linux xen-blkback and re-write the state
 185      * to trigger the frontend watch.
 186      */
 187     xen_device_backend_printf(xendev, "state", "%u", state);
 188 }
 189
 190 static const BlockDevOps xen_block_dev_ops = {
 191     .resize_cb = xen_block_resize_cb,
 192 };
 193
 194 static void xen_block_realize(XenDevice *xendev, Error **errp)
 195 {
 196     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 197     XenBlockDeviceClass *blockdev_class =
 198         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
 199     const char *type = object_get_typename(OBJECT(blockdev));
 200     XenBlockVdev *vdev = &blockdev->props.vdev;
 201     BlockConf *conf = &blockdev->props.conf;
 202     BlockBackend *blk = conf->blk;
 203     Error *local_err = NULL;
 204
 205     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
 206         error_setg(errp, "vdev property not set");
 207         return;
 208     }
 209
 210     trace_xen_block_realize(type, vdev->disk, vdev->partition);
 211
 212     if (blockdev_class->realize) {
 213         blockdev_class->realize(blockdev, &local_err);
 214         if (local_err) {
 215             error_propagate(errp, local_err);
 216             return;
 217         }
 218     }
 219
 220     /*
 221      * The blkif protocol does not deal with removable media, so it must
 222      * always be present, even for CDRom devices.
 223      */
 224     assert(blk);
 225     if (!blk_is_inserted(blk)) {
 226         error_setg(errp, "device needs media, but drive is empty");
 227         return;
 228     }
 229
 230     if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
 231                                        true, errp)) {
 232         return;
 233     }
 234
 235     if (!(blockdev->info & VDISK_CDROM) &&
 236         !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) {
 237         return;
 238     }
 239
 240     blkconf_blocksizes(conf);
 241
 242     if (conf->logical_block_size > conf->physical_block_size) {
 243         error_setg(
 244             errp, "logical_block_size > physical_block_size not supported");
 245         return;
 246     }
 247
 248     blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev);
 249     blk_set_guest_block_size(blk, conf->logical_block_size);
 250
 251     if (conf->discard_granularity == -1) {
 252         conf->discard_granularity = conf->physical_block_size;
 253     }
 254
 255     if (blk_get_flags(blk) & BDRV_O_UNMAP) {
 256         xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
 257         xen_device_backend_printf(xendev, "discard-granularity", "%u",
 258                                   conf->discard_granularity);
 259     }
 260
 261     xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
 262     xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
 263                               blockdev->props.max_ring_page_order);
 264     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
 265
 266     xen_device_frontend_printf(xendev, "virtual-device", "%lu",
 267                                vdev->number);
 268     xen_device_frontend_printf(xendev, "device-type", "%s",
 269                                blockdev->device_type);
 270
 271     xen_device_backend_printf(xendev, "sector-size", "%u",
 272                               conf->logical_block_size);
 273
 274     xen_block_set_size(blockdev);
 275
 276     blockdev->dataplane =
 277         xen_block_dataplane_create(xendev, blk, conf->logical_block_size,
 278                                    blockdev->props.iothread);
 279 }
 280
 281 static void xen_block_frontend_changed(XenDevice *xendev,
 282                                        enum xenbus_state frontend_state,
 283                                        Error **errp)
 284 {
 285     enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
 286     Error *local_err = NULL;
 287
 288     switch (frontend_state) {
 289     case XenbusStateInitialised:
 290     case XenbusStateConnected:
 291         if (backend_state == XenbusStateConnected) {
 292             break;
 293         }
 294
 295         xen_block_disconnect(xendev, &local_err);
 296         if (local_err) {
 297             error_propagate(errp, local_err);
 298             break;
 299         }
 300
 301         xen_block_connect(xendev, &local_err);
 302         if (local_err) {
 303             error_propagate(errp, local_err);
 304             break;
 305         }
 306
 307         xen_device_backend_set_state(xendev, XenbusStateConnected);
 308         break;
 309
 310     case XenbusStateClosing:
 311         xen_device_backend_set_state(xendev, XenbusStateClosing);
 312         break;
 313
 314     case XenbusStateClosed:
 315         xen_block_disconnect(xendev, &local_err);
 316         if (local_err) {
 317             error_propagate(errp, local_err);
 318             break;
 319         }
 320
 321         xen_device_backend_set_state(xendev, XenbusStateClosed);
 322         break;
 323
 324     default:
 325         break;
 326     }
 327 }
 328
 329 static char *disk_to_vbd_name(unsigned int disk)
 330 {
 331     char *name, *prefix = (disk >= 26) ?
 332         disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
 333
 334     name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26);
 335     g_free(prefix);
 336
 337     return name;
 338 }
 339
 340 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
 341                                void *opaque, Error **errp)
 342 {
 343     DeviceState *dev = DEVICE(obj);
 344     Property *prop = opaque;
 345     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 346     char *str;
 347
 348     switch (vdev->type) {
 349     case XEN_BLOCK_VDEV_TYPE_DP:
 350         str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
 351         break;
 352
 353     case XEN_BLOCK_VDEV_TYPE_XVD:
 354     case XEN_BLOCK_VDEV_TYPE_HD:
 355     case XEN_BLOCK_VDEV_TYPE_SD: {
 356         char *name = disk_to_vbd_name(vdev->disk);
 357
 358         str = g_strdup_printf("%s%s%lu",
 359                               (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
 360                               "xvd" :
 361                               (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
 362                               "hd" :
 363                               "sd",
 364                               name, vdev->partition);
 365         g_free(name);
 366         break;
 367     }
 368     default:
 369         error_setg(errp, "invalid vdev type");
 370         return;
 371     }
 372
 373     visit_type_str(v, name, &str, errp);
 374     g_free(str);
 375 }
 376
 377 static int vbd_name_to_disk(const char *name, const char **endp,
 378                             unsigned long *disk)
 379 {
 380     unsigned int n = 0;
 381
 382     while (*name != '\0') {
 383         if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
 384             break;
 385         }
 386
 387         n *= 26;
 388         n += *name++ - 'a' + 1;
 389     }
 390     *endp = name;
 391
 392     if (!n) {
 393         return -1;
 394     }
 395
 396     *disk = n - 1;
 397
 398     return 0;
 399 }
 400
 401 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
 402                                void *opaque, Error **errp)
 403 {
 404     DeviceState *dev = DEVICE(obj);
 405     Property *prop = opaque;
 406     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
 407     Error *local_err = NULL;
 408     char *str, *p;
 409     const char *end;
 410
 411     if (dev->realized) {
 412         qdev_prop_set_after_realize(dev, name, errp);
 413         return;
 414     }
 415
 416     visit_type_str(v, name, &str, &local_err);
 417     if (local_err) {
 418         error_propagate(errp, local_err);
 419         return;
 420     }
 421
 422     p = strchr(str, 'd');
 423     if (!p) {
 424         goto invalid;
 425     }
 426
 427     *p++ = '\0';
 428     if (*str == '\0') {
 429         vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
 430     } else if (strcmp(str, "xv") == 0) {
 431         vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
 432     } else if (strcmp(str, "h") == 0) {
 433         vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
 434     } else if (strcmp(str, "s") == 0) {
 435         vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
 436     } else {
 437         goto invalid;
 438     }
 439
 440     if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
 441         if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
 442             goto invalid;
 443         }
 444
 445         if (*end == 'p') {
 446             if (*(++end) == '\0') {
 447                 goto invalid;
 448             }
 449         }
 450     } else {
 451         if (vbd_name_to_disk(p, &end, &vdev->disk)) {
 452             goto invalid;
 453         }
 454     }
 455
 456     if (*end != '\0') {
 457         p = (char *)end;
 458
 459         if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
 460             goto invalid;
 461         }
 462
 463         if (*end != '\0') {
 464             goto invalid;
 465         }
 466     } else {
 467         vdev->partition = 0;
 468     }
 469
 470     switch (vdev->type) {
 471     case XEN_BLOCK_VDEV_TYPE_DP:
 472     case XEN_BLOCK_VDEV_TYPE_XVD:
 473         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 474             vdev->number = (202 << 8) | (vdev->disk << 4) |
 475                 vdev->partition;
 476         } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
 477             vdev->number = (1 << 28) | (vdev->disk << 8) |
 478                 vdev->partition;
 479         } else {
 480             goto invalid;
 481         }
 482         break;
 483
 484     case XEN_BLOCK_VDEV_TYPE_HD:
 485         if ((vdev->disk == 0 || vdev->disk == 1) &&
 486             vdev->partition < (1 << 6)) {
 487             vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
 488         } else if ((vdev->disk == 2 || vdev->disk == 3) &&
 489                    vdev->partition < (1 << 6)) {
 490             vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
 491                 vdev->partition;
 492         } else {
 493             goto invalid;
 494         }
 495         break;
 496
 497     case XEN_BLOCK_VDEV_TYPE_SD:
 498         if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
 499             vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
 500         } else {
 501             goto invalid;
 502         }
 503         break;
 504
 505     default:
 506         goto invalid;
 507     }
 508
 509     g_free(str);
 510     return;
 511
 512 invalid:
 513     error_setg(errp, "invalid virtual disk specifier");
 514
 515     vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
 516     g_free(str);
 517 }
 518
 519 /*
 520  * This property deals with 'vdev' names adhering to the Xen VBD naming
 521  * scheme described in:
 522  *
 523  * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
 524  */
 525 const PropertyInfo xen_block_prop_vdev = {
 526     .name  = "str",
 527     .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
 528     .get = xen_block_get_vdev,
 529     .set = xen_block_set_vdev,
 530 };
 531
 532 static Property xen_block_props[] = {
 533     DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
 534                 xen_block_prop_vdev, XenBlockVdev),
 535     DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
 536     DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
 537                        props.max_ring_page_order, 4),
 538     DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
 539                      TYPE_IOTHREAD, IOThread *),
 540     DEFINE_PROP_END_OF_LIST()
 541 };
 542
 543 static void xen_block_class_init(ObjectClass *class, void *data)
 544 {
 545     DeviceClass *dev_class = DEVICE_CLASS(class);
 546     XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
 547
 548     xendev_class->backend = "qdisk";
 549     xendev_class->device = "vbd";
 550     xendev_class->get_name = xen_block_get_name;
 551     xendev_class->realize = xen_block_realize;
 552     xendev_class->frontend_changed = xen_block_frontend_changed;
 553     xendev_class->unrealize = xen_block_unrealize;
 554
 555     dev_class->props = xen_block_props;
 556 }
 557
 558 static const TypeInfo xen_block_type_info = {
 559     .name = TYPE_XEN_BLOCK_DEVICE,
 560     .parent = TYPE_XEN_DEVICE,
 561     .instance_size = sizeof(XenBlockDevice),
 562     .abstract = true,
 563     .class_size = sizeof(XenBlockDeviceClass),
 564     .class_init = xen_block_class_init,
 565 };
 566
 567 static void xen_disk_unrealize(XenBlockDevice *blockdev, Error **errp)
 568 {
 569     trace_xen_disk_unrealize();
 570 }
 571
 572 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
 573 {
 574     BlockConf *conf = &blockdev->props.conf;
 575
 576     trace_xen_disk_realize();
 577
 578     blockdev->device_type = "disk";
 579
 580     if (!conf->blk) {
 581         error_setg(errp, "drive property not set");
 582         return;
 583     }
 584
 585     blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
 586 }
 587
 588 static void xen_disk_class_init(ObjectClass *class, void *data)
 589 {
 590     DeviceClass *dev_class = DEVICE_CLASS(class);
 591     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 592
 593     blockdev_class->realize = xen_disk_realize;
 594     blockdev_class->unrealize = xen_disk_unrealize;
 595
 596     dev_class->desc = "Xen Disk Device";
 597 }
 598
 599 static const TypeInfo xen_disk_type_info = {
 600     .name = TYPE_XEN_DISK_DEVICE,
 601     .parent = TYPE_XEN_BLOCK_DEVICE,
 602     .instance_size = sizeof(XenDiskDevice),
 603     .class_init = xen_disk_class_init,
 604 };
 605
 606 static void xen_cdrom_unrealize(XenBlockDevice *blockdev, Error **errp)
 607 {
 608     trace_xen_cdrom_unrealize();
 609 }
 610
 611 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
 612 {
 613     BlockConf *conf = &blockdev->props.conf;
 614
 615     trace_xen_cdrom_realize();
 616
 617     blockdev->device_type = "cdrom";
 618
 619     if (!conf->blk) {
 620         int rc;
 621
 622         /* Set up an empty drive */
 623         conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
 624
 625         rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
 626         if (!rc) {
 627             error_setg_errno(errp, -rc, "failed to create drive");
 628             return;
 629         }
 630     }
 631
 632     blockdev->info = VDISK_READONLY | VDISK_CDROM;
 633 }
 634
 635 static void xen_cdrom_class_init(ObjectClass *class, void *data)
 636 {
 637     DeviceClass *dev_class = DEVICE_CLASS(class);
 638     XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
 639
 640     blockdev_class->realize = xen_cdrom_realize;
 641     blockdev_class->unrealize = xen_cdrom_unrealize;
 642
 643     dev_class->desc = "Xen CD-ROM Device";
 644 }
 645
 646 static const TypeInfo xen_cdrom_type_info = {
 647     .name = TYPE_XEN_CDROM_DEVICE,
 648     .parent = TYPE_XEN_BLOCK_DEVICE,
 649     .instance_size = sizeof(XenCDRomDevice),
 650     .class_init = xen_cdrom_class_init,
 651 };
 652
 653 static void xen_block_register_types(void)
 654 {
 655     type_register_static(&xen_block_type_info);
 656     type_register_static(&xen_disk_type_info);
 657     type_register_static(&xen_cdrom_type_info);
 658 }
 659
 660 type_init(xen_block_register_types)
 661
 662 static void xen_block_blockdev_del(const char *node_name, Error **errp)
 663 {
 664     trace_xen_block_blockdev_del(node_name);
 665
 666     qmp_blockdev_del(node_name, errp);
 667 }
 668
 669 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
 670                                     Error **errp)
 671 {
 672     const char *driver = qdict_get_try_str(qdict, "driver");
 673     BlockdevOptions *options = NULL;
 674     Error *local_err = NULL;
 675     char *node_name;
 676     Visitor *v;
 677
 678     if (!driver) {
 679         error_setg(errp, "no 'driver' parameter");
 680         return NULL;
 681     }
 682
 683     node_name = g_strdup_printf("%s-%s", id, driver);
 684     qdict_put_str(qdict, "node-name", node_name);
 685
 686     trace_xen_block_blockdev_add(node_name);
 687
 688     v = qobject_input_visitor_new(QOBJECT(qdict));
 689     visit_type_BlockdevOptions(v, NULL, &options, &local_err);
 690     visit_free(v);
 691
 692     if (local_err) {
 693         error_propagate(errp, local_err);
 694         goto fail;
 695     }
 696
 697     qmp_blockdev_add(options, &local_err);
 698
 699     if (local_err) {
 700         error_propagate(errp, local_err);
 701         goto fail;
 702     }
 703
 704     qapi_free_BlockdevOptions(options);
 705
 706     return node_name;
 707
 708 fail:
 709     if (options) {
 710         qapi_free_BlockdevOptions(options);
 711     }
 712     g_free(node_name);
 713
 714     return NULL;
 715 }
 716
 717 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
 718 {
 719     char *node_name = drive->node_name;
 720
 721     if (node_name) {
 722         Error *local_err = NULL;
 723
 724         xen_block_blockdev_del(node_name, &local_err);
 725         if (local_err) {
 726             error_propagate(errp, local_err);
 727             return;
 728         }
 729         g_free(node_name);
 730         drive->node_name = NULL;
 731     }
 732     g_free(drive->id);
 733     g_free(drive);
 734 }
 735
 736 static XenBlockDrive *xen_block_drive_create(const char *id,
 737                                              const char *device_type,
 738                                              QDict *opts, Error **errp)
 739 {
 740     const char *params = qdict_get_try_str(opts, "params");
 741     const char *mode = qdict_get_try_str(opts, "mode");
 742     const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
 743     const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
 744     char *driver = NULL;
 745     char *filename = NULL;
 746     XenBlockDrive *drive = NULL;
 747     Error *local_err = NULL;
 748     QDict *file_layer;
 749     QDict *driver_layer;
 750
 751     if (params) {
 752         char **v = g_strsplit(params, ":", 2);
 753
 754         if (v[1] == NULL) {
 755             filename = g_strdup(v[0]);
 756             driver = g_strdup("raw");
 757         } else {
 758             if (strcmp(v[0], "aio") == 0) {
 759                 driver = g_strdup("raw");
 760             } else if (strcmp(v[0], "vhd") == 0) {
 761                 driver = g_strdup("vpc");
 762             } else {
 763                 driver = g_strdup(v[0]);
 764             }
 765             filename = g_strdup(v[1]);
 766         }
 767
 768         g_strfreev(v);
 769     } else {
 770         error_setg(errp, "no params");
 771         goto done;
 772     }
 773
 774     assert(filename);
 775     assert(driver);
 776
 777     drive = g_new0(XenBlockDrive, 1);
 778     drive->id = g_strdup(id);
 779
 780     file_layer = qdict_new();
 781     driver_layer = qdict_new();
 782
 783     qdict_put_str(file_layer, "driver", "file");
 784     qdict_put_str(file_layer, "filename", filename);
 785     g_free(filename);
 786
 787     if (mode && *mode != 'w') {
 788         qdict_put_bool(file_layer, "read-only", true);
 789     }
 790
 791     if (direct_io_safe) {
 792         unsigned long value;
 793
 794         if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
 795             QDict *cache_qdict = qdict_new();
 796
 797             qdict_put_bool(cache_qdict, "direct", true);
 798             qdict_put(file_layer, "cache", cache_qdict);
 799
 800             qdict_put_str(file_layer, "aio", "native");
 801         }
 802     }
 803
 804     if (discard_enable) {
 805         unsigned long value;
 806
 807         if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
 808             qdict_put_str(file_layer, "discard", "unmap");
 809             qdict_put_str(driver_layer, "discard", "unmap");
 810         }
 811     }
 812
 813     /*
 814      * It is necessary to turn file locking off as an emulated device
 815      * may have already opened the same image file.
 816      */
 817     qdict_put_str(file_layer, "locking", "off");
 818
 819     qdict_put_str(driver_layer, "driver", driver);
 820     g_free(driver);
 821
 822     qdict_put(driver_layer, "file", file_layer);
 823
 824     g_assert(!drive->node_name);
 825     drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
 826                                               &local_err);
 827
 828     qobject_unref(driver_layer);
 829
 830 done:
 831     if (local_err) {
 832         error_propagate(errp, local_err);
 833         xen_block_drive_destroy(drive, NULL);
 834         return NULL;
 835     }
 836
 837     return drive;
 838 }
 839
 840 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
 841 {
 842     return drive->node_name ? drive->node_name : "";
 843 }
 844
 845 static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
 846                                        Error **errp)
 847 {
 848     qmp_object_del(iothread->id, errp);
 849
 850     g_free(iothread->id);
 851     g_free(iothread);
 852 }
 853
 854 static XenBlockIOThread *xen_block_iothread_create(const char *id,
 855                                                    Error **errp)
 856 {
 857     XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
 858     Error *local_err = NULL;
 859
 860     iothread->id = g_strdup(id);
 861
 862     qmp_object_add(TYPE_IOTHREAD, id, false, NULL, &local_err);
 863     if (local_err) {
 864         error_propagate(errp, local_err);
 865
 866         g_free(iothread->id);
 867         g_free(iothread);
 868         return NULL;
 869     }
 870
 871     return iothread;
 872 }
 873
 874 static void xen_block_device_create(XenBackendInstance *backend,
 875                                     QDict *opts, Error **errp)
 876 {
 877     XenBus *xenbus = xen_backend_get_bus(backend);
 878     const char *name = xen_backend_get_name(backend);
 879     unsigned long number;
 880     const char *vdev, *device_type;
 881     XenBlockDrive *drive = NULL;
 882     XenBlockIOThread *iothread = NULL;
 883     XenDevice *xendev = NULL;
 884     Error *local_err = NULL;
 885     const char *type;
 886     XenBlockDevice *blockdev;
 887
 888     if (qemu_strtoul(name, NULL, 10, &number)) {
 889         error_setg(errp, "failed to parse name '%s'", name);
 890         goto fail;
 891     }
 892
 893     trace_xen_block_device_create(number);
 894
 895     vdev = qdict_get_try_str(opts, "dev");
 896     if (!vdev) {
 897         error_setg(errp, "no dev parameter");
 898         goto fail;
 899     }
 900
 901     device_type = qdict_get_try_str(opts, "device-type");
 902     if (!device_type) {
 903         error_setg(errp, "no device-type parameter");
 904         goto fail;
 905     }
 906
 907     if (!strcmp(device_type, "disk")) {
 908         type = TYPE_XEN_DISK_DEVICE;
 909     } else if (!strcmp(device_type, "cdrom")) {
 910         type = TYPE_XEN_CDROM_DEVICE;
 911     } else {
 912         error_setg(errp, "invalid device-type parameter '%s'", device_type);
 913         goto fail;
 914     }
 915
 916     drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
 917     if (!drive) {
 918         error_propagate_prepend(errp, local_err, "failed to create drive: ");
 919         goto fail;
 920     }
 921
 922     iothread = xen_block_iothread_create(vdev, &local_err);
 923     if (local_err) {
 924         error_propagate_prepend(errp, local_err,
 925                                 "failed to create iothread: ");
 926         goto fail;
 927     }
 928
 929     xendev = XEN_DEVICE(qdev_create(BUS(xenbus), type));
 930     blockdev = XEN_BLOCK_DEVICE(xendev);
 931
 932     object_property_set_str(OBJECT(xendev), vdev, "vdev", &local_err);
 933     if (local_err) {
 934         error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
 935         goto fail;
 936     }
 937
 938     object_property_set_str(OBJECT(xendev),
 939                             xen_block_drive_get_node_name(drive), "drive",
 940                             &local_err);
 941     if (local_err) {
 942         error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
 943         goto fail;
 944     }
 945
 946     object_property_set_str(OBJECT(xendev), iothread->id, "iothread",
 947                             &local_err);
 948     if (local_err) {
 949         error_propagate_prepend(errp, local_err,
 950                                 "failed to set 'iothread': ");
 951         goto fail;
 952     }
 953
 954     blockdev->iothread = iothread;
 955     blockdev->drive = drive;
 956
 957     object_property_set_bool(OBJECT(xendev), true, "realized", &local_err);
 958     if (local_err) {
 959         error_propagate_prepend(errp, local_err,
 960                                 "realization of device %s failed: ",
 961                                 type);
 962         goto fail;
 963     }
 964
 965     xen_backend_set_device(backend, xendev);
 966     return;
 967
 968 fail:
 969     if (xendev) {
 970         object_unparent(OBJECT(xendev));
 971     }
 972
 973     if (iothread) {
 974         xen_block_iothread_destroy(iothread, NULL);
 975     }
 976
 977     if (drive) {
 978         xen_block_drive_destroy(drive, NULL);
 979     }
 980 }
 981
 982 static void xen_block_device_destroy(XenBackendInstance *backend,
 983                                      Error **errp)
 984 {
 985     XenDevice *xendev = xen_backend_get_device(backend);
 986     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
 987     XenBlockVdev *vdev = &blockdev->props.vdev;
 988     XenBlockDrive *drive = blockdev->drive;
 989     XenBlockIOThread *iothread = blockdev->iothread;
 990
 991     trace_xen_block_device_destroy(vdev->number);
 992
 993     object_unparent(OBJECT(xendev));
 994
 995     if (iothread) {
 996         Error *local_err = NULL;
 997
 998         xen_block_iothread_destroy(iothread, &local_err);
 999         if (local_err) {
1000             error_propagate_prepend(errp, local_err,
1001                                 "failed to destroy iothread: ");
1002             return;
1003         }
1004     }
1005
1006     if (drive) {
1007         Error *local_err = NULL;
1008
1009         xen_block_drive_destroy(drive, &local_err);
1010         if (local_err) {
1011             error_propagate_prepend(errp, local_err,
1012                                 "failed to destroy drive: ");
1013         }
1014     }
1015 }
1016
1017 static const XenBackendInfo xen_block_backend_info = {
1018     .type = "qdisk",
1019     .create = xen_block_device_create,
1020     .destroy = xen_block_device_destroy,
1021 };
1022
1023 static void xen_block_register_backend(void)
1024 {
1025     xen_backend_register(&xen_block_backend_info);
1026 }
1027
1028 xen_backend_init(xen_block_register_backend);