| 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 "qobject/qdict.h" |
| 20 | #include "qobject/qstring.h" |
| 21 | #include "qom/object_interfaces.h" |
| 22 | #include "hw/block/xen_blkif.h" |
| 23 | #include "hw/core/qdev-properties.h" |
| 24 | #include "hw/xen/xen-block.h" |
| 25 | #include "hw/xen/xen-backend.h" |
| 26 | #include "system/blockdev.h" |
| 27 | #include "system/block-backend.h" |
| 28 | #include "system/iothread.h" |
| 29 | #include "dataplane/xen-block.h" |
| 30 | #include "hw/xen/interface/io/xs_wire.h" |
| 31 | #include "trace.h" |
| 32 | |
| 33 | #define XVDA_MAJOR 202 |
| 34 | #define XVDQ_MAJOR (1 << 20) |
| 35 | #define XVDBGQCV_MAJOR ((1 << 21) - 1) |
| 36 | #define HDA_MAJOR 3 |
| 37 | #define HDC_MAJOR 22 |
| 38 | #define SDA_MAJOR 8 |
| 39 | |
| 40 | |
| 41 | static int vdev_to_diskno(unsigned int vdev_nr) |
| 42 | { |
| 43 | switch (vdev_nr >> 8) { |
| 44 | case XVDA_MAJOR: |
| 45 | case SDA_MAJOR: |
| 46 | return (vdev_nr >> 4) & 0x15; |
| 47 | |
| 48 | case HDA_MAJOR: |
| 49 | return (vdev_nr >> 6) & 1; |
| 50 | |
| 51 | case HDC_MAJOR: |
| 52 | return ((vdev_nr >> 6) & 1) + 2; |
| 53 | |
| 54 | case XVDQ_MAJOR ... XVDBGQCV_MAJOR: |
| 55 | return (vdev_nr >> 8) & 0xfffff; |
| 56 | |
| 57 | default: |
| 58 | return -1; |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | #define MAX_AUTO_VDEV 4096 |
| 63 | |
| 64 | /* |
| 65 | * Find a free device name in the xvda → xvdfan range and set it in |
| 66 | * blockdev->props.vdev. Our definition of "free" is that there must |
| 67 | * be no other disk or partition with the same disk number. |
| 68 | * |
| 69 | * You are technically permitted to have all of hda, hda1, sda, sda1, |
| 70 | * xvda and xvda1 as *separate* PV block devices with separate backing |
| 71 | * stores. That doesn't make it a good idea. This code will skip xvda |
| 72 | * if *any* of those "conflicting" devices already exists. |
| 73 | * |
| 74 | * The limit of xvdfan (disk 4095) is fairly arbitrary just to avoid a |
| 75 | * stupidly sized bitmap, but Linux as of v6.6 doesn't support anything |
| 76 | * higher than that anyway. |
| 77 | */ |
| 78 | static bool xen_block_find_free_vdev(XenBlockDevice *blockdev, Error **errp) |
| 79 | { |
| 80 | XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(blockdev))); |
| 81 | unsigned long used_devs[BITS_TO_LONGS(MAX_AUTO_VDEV)]; |
| 82 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 83 | char fe_path[XENSTORE_ABS_PATH_MAX + 1]; |
| 84 | char **existing_frontends; |
| 85 | unsigned int nr_existing = 0; |
| 86 | unsigned int vdev_nr; |
| 87 | int i, disk = 0; |
| 88 | |
| 89 | snprintf(fe_path, sizeof(fe_path), "/local/domain/%u/device/vbd", |
| 90 | blockdev->xendev.frontend_id); |
| 91 | |
| 92 | existing_frontends = qemu_xen_xs_directory(xenbus->xsh, XBT_NULL, fe_path, |
| 93 | &nr_existing); |
| 94 | if (!existing_frontends) { |
| 95 | if (errno == ENOENT) { |
| 96 | /* |
| 97 | * If the frontend directory doesn't exist because there are |
| 98 | * no existing vbd devices, that's fine. Just ensure that we |
| 99 | * don't dereference the NULL existing_frontends pointer, by |
| 100 | * checking that nr_existing is zero so the loop below is not |
| 101 | * entered. |
| 102 | * |
| 103 | * In fact this is redundant since nr_existing is initialized |
| 104 | * to zero, but setting it again here makes it abundantly clear |
| 105 | * to Coverity, and to the human reader who doesn't know the |
| 106 | * semantics of qemu_xen_xs_directory() off the top of their |
| 107 | * head. |
| 108 | */ |
| 109 | nr_existing = 0; |
| 110 | } else { |
| 111 | /* All other errors accessing the frontend directory are fatal. */ |
| 112 | error_setg_errno(errp, errno, "cannot read %s", fe_path); |
| 113 | return false; |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | memset(used_devs, 0, sizeof(used_devs)); |
| 118 | for (i = 0; i < nr_existing; i++) { |
| 119 | if (qemu_strtoui(existing_frontends[i], NULL, 10, &vdev_nr)) { |
| 120 | free(existing_frontends[i]); |
| 121 | continue; |
| 122 | } |
| 123 | |
| 124 | free(existing_frontends[i]); |
| 125 | |
| 126 | disk = vdev_to_diskno(vdev_nr); |
| 127 | if (disk < 0 || disk >= MAX_AUTO_VDEV) { |
| 128 | continue; |
| 129 | } |
| 130 | |
| 131 | set_bit(disk, used_devs); |
| 132 | } |
| 133 | free(existing_frontends); |
| 134 | |
| 135 | disk = find_first_zero_bit(used_devs, MAX_AUTO_VDEV); |
| 136 | if (disk == MAX_AUTO_VDEV) { |
| 137 | error_setg(errp, "cannot find device vdev for block device"); |
| 138 | return false; |
| 139 | } |
| 140 | |
| 141 | vdev->type = XEN_BLOCK_VDEV_TYPE_XVD; |
| 142 | vdev->partition = 0; |
| 143 | vdev->disk = disk; |
| 144 | if (disk < (1 << 4)) { |
| 145 | vdev->number = (XVDA_MAJOR << 8) | (disk << 4); |
| 146 | } else { |
| 147 | vdev->number = (XVDQ_MAJOR << 8) | (disk << 8); |
| 148 | } |
| 149 | return true; |
| 150 | } |
| 151 | |
| 152 | static char *xen_block_get_name(XenDevice *xendev, Error **errp) |
| 153 | { |
| 154 | XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); |
| 155 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 156 | |
| 157 | if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID && |
| 158 | !xen_block_find_free_vdev(blockdev, errp)) { |
| 159 | return NULL; |
| 160 | } |
| 161 | return g_strdup_printf("%lu", vdev->number); |
| 162 | } |
| 163 | |
| 164 | static void xen_block_disconnect(XenDevice *xendev, Error **errp) |
| 165 | { |
| 166 | XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); |
| 167 | const char *type = object_get_typename(OBJECT(blockdev)); |
| 168 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 169 | |
| 170 | trace_xen_block_disconnect(type, vdev->disk, vdev->partition); |
| 171 | |
| 172 | xen_block_dataplane_stop(blockdev->dataplane); |
| 173 | } |
| 174 | |
| 175 | static void xen_block_connect(XenDevice *xendev, Error **errp) |
| 176 | { |
| 177 | XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); |
| 178 | const char *type = object_get_typename(OBJECT(blockdev)); |
| 179 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 180 | BlockConf *conf = &blockdev->props.conf; |
| 181 | unsigned int feature_large_sector_size; |
| 182 | unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol; |
| 183 | char *str; |
| 184 | |
| 185 | trace_xen_block_connect(type, vdev->disk, vdev->partition); |
| 186 | |
| 187 | if (xen_device_frontend_scanf(xendev, "feature-large-sector-size", "%u", |
| 188 | &feature_large_sector_size) != 1) { |
| 189 | feature_large_sector_size = 0; |
| 190 | } |
| 191 | |
| 192 | if (feature_large_sector_size != 1 && |
| 193 | conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) { |
| 194 | error_setg(errp, "logical_block_size != %u not supported by frontend", |
| 195 | XEN_BLKIF_SECTOR_SIZE); |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u", |
| 200 | &order) != 1) { |
| 201 | nr_ring_ref = 1; |
| 202 | ring_ref = g_new(unsigned int, nr_ring_ref); |
| 203 | |
| 204 | if (xen_device_frontend_scanf(xendev, "ring-ref", "%u", |
| 205 | &ring_ref[0]) != 1) { |
| 206 | error_setg(errp, "failed to read ring-ref"); |
| 207 | g_free(ring_ref); |
| 208 | return; |
| 209 | } |
| 210 | } else if (qemu_xen_gnttab_can_map_multi() && |
| 211 | order <= blockdev->props.max_ring_page_order) { |
| 212 | unsigned int i; |
| 213 | |
| 214 | nr_ring_ref = 1 << order; |
| 215 | ring_ref = g_new(unsigned int, nr_ring_ref); |
| 216 | |
| 217 | for (i = 0; i < nr_ring_ref; i++) { |
| 218 | const char *key = g_strdup_printf("ring-ref%u", i); |
| 219 | |
| 220 | if (xen_device_frontend_scanf(xendev, key, "%u", |
| 221 | &ring_ref[i]) != 1) { |
| 222 | error_setg(errp, "failed to read %s", key); |
| 223 | g_free((gpointer)key); |
| 224 | g_free(ring_ref); |
| 225 | return; |
| 226 | } |
| 227 | |
| 228 | g_free((gpointer)key); |
| 229 | } |
| 230 | } else { |
| 231 | error_setg(errp, "invalid ring-page-order (%d)", order); |
| 232 | return; |
| 233 | } |
| 234 | |
| 235 | if (xen_device_frontend_scanf(xendev, "event-channel", "%u", |
| 236 | &event_channel) != 1) { |
| 237 | error_setg(errp, "failed to read event-channel"); |
| 238 | g_free(ring_ref); |
| 239 | return; |
| 240 | } |
| 241 | |
| 242 | str = xen_device_frontend_read(xendev, "protocol"); |
| 243 | if (!str) { |
| 244 | /* x86 defaults to the 32-bit protocol even for 64-bit guests. */ |
| 245 | if (object_dynamic_cast(OBJECT(qdev_get_machine()), "x86-machine")) { |
| 246 | protocol = BLKIF_PROTOCOL_X86_32; |
| 247 | } else { |
| 248 | protocol = BLKIF_PROTOCOL_NATIVE; |
| 249 | } |
| 250 | } else { |
| 251 | if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) { |
| 252 | protocol = BLKIF_PROTOCOL_X86_32; |
| 253 | } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) { |
| 254 | protocol = BLKIF_PROTOCOL_X86_64; |
| 255 | } else { |
| 256 | protocol = BLKIF_PROTOCOL_NATIVE; |
| 257 | } |
| 258 | |
| 259 | free(str); |
| 260 | } |
| 261 | |
| 262 | xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref, |
| 263 | event_channel, protocol, errp); |
| 264 | |
| 265 | g_free(ring_ref); |
| 266 | } |
| 267 | |
| 268 | static void xen_block_unrealize(XenDevice *xendev) |
| 269 | { |
| 270 | XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); |
| 271 | XenBlockDeviceClass *blockdev_class = |
| 272 | XEN_BLOCK_DEVICE_GET_CLASS(xendev); |
| 273 | const char *type = object_get_typename(OBJECT(blockdev)); |
| 274 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 275 | |
| 276 | if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { |
| 277 | return; |
| 278 | } |
| 279 | |
| 280 | trace_xen_block_unrealize(type, vdev->disk, vdev->partition); |
| 281 | |
| 282 | /* Disconnect from the frontend in case this has not already happened */ |
| 283 | xen_block_disconnect(xendev, NULL); |
| 284 | |
| 285 | xen_block_dataplane_destroy(blockdev->dataplane); |
| 286 | blockdev->dataplane = NULL; |
| 287 | |
| 288 | if (blockdev_class->unrealize) { |
| 289 | blockdev_class->unrealize(blockdev); |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | static void xen_block_set_size(XenBlockDevice *blockdev) |
| 294 | { |
| 295 | const char *type = object_get_typename(OBJECT(blockdev)); |
| 296 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 297 | BlockConf *conf = &blockdev->props.conf; |
| 298 | int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size; |
| 299 | XenDevice *xendev = XEN_DEVICE(blockdev); |
| 300 | |
| 301 | trace_xen_block_size(type, vdev->disk, vdev->partition, sectors); |
| 302 | |
| 303 | xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors); |
| 304 | } |
| 305 | |
| 306 | static void xen_block_resize_cb(void *opaque) |
| 307 | { |
| 308 | XenBlockDevice *blockdev = opaque; |
| 309 | XenDevice *xendev = XEN_DEVICE(blockdev); |
| 310 | enum xenbus_state state = xen_device_backend_get_state(xendev); |
| 311 | |
| 312 | xen_block_set_size(blockdev); |
| 313 | |
| 314 | /* |
| 315 | * Mimic the behaviour of Linux xen-blkback and re-write the state |
| 316 | * to trigger the frontend watch. |
| 317 | */ |
| 318 | xen_device_backend_printf(xendev, "state", "%u", state); |
| 319 | } |
| 320 | |
| 321 | /* Suspend request handling */ |
| 322 | static void xen_block_drained_begin(void *opaque) |
| 323 | { |
| 324 | XenBlockDevice *blockdev = opaque; |
| 325 | |
| 326 | xen_block_dataplane_detach(blockdev->dataplane); |
| 327 | } |
| 328 | |
| 329 | /* Resume request handling */ |
| 330 | static void xen_block_drained_end(void *opaque) |
| 331 | { |
| 332 | XenBlockDevice *blockdev = opaque; |
| 333 | |
| 334 | xen_block_dataplane_attach(blockdev->dataplane); |
| 335 | } |
| 336 | |
| 337 | static const BlockDevOps xen_block_dev_ops = { |
| 338 | .resize_cb = xen_block_resize_cb, |
| 339 | .drained_begin = xen_block_drained_begin, |
| 340 | .drained_end = xen_block_drained_end, |
| 341 | }; |
| 342 | |
| 343 | static void xen_block_realize(XenDevice *xendev, Error **errp) |
| 344 | { |
| 345 | ERRP_GUARD(); |
| 346 | XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); |
| 347 | XenBlockDeviceClass *blockdev_class = |
| 348 | XEN_BLOCK_DEVICE_GET_CLASS(xendev); |
| 349 | const char *type = object_get_typename(OBJECT(blockdev)); |
| 350 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 351 | BlockConf *conf = &blockdev->props.conf; |
| 352 | BlockBackend *blk = conf->blk; |
| 353 | |
| 354 | if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { |
| 355 | error_setg(errp, "vdev property not set"); |
| 356 | return; |
| 357 | } |
| 358 | |
| 359 | trace_xen_block_realize(type, vdev->disk, vdev->partition); |
| 360 | |
| 361 | if (blockdev_class->realize) { |
| 362 | blockdev_class->realize(blockdev, errp); |
| 363 | if (*errp) { |
| 364 | return; |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | /* |
| 369 | * The blkif protocol does not deal with removable media, so it must |
| 370 | * always be present, even for CDRom devices. |
| 371 | */ |
| 372 | assert(blk); |
| 373 | if (!blk_is_inserted(blk)) { |
| 374 | error_setg(errp, "device needs media, but drive is empty"); |
| 375 | return; |
| 376 | } |
| 377 | |
| 378 | if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY, |
| 379 | true, errp)) { |
| 380 | return; |
| 381 | } |
| 382 | |
| 383 | if (!(blockdev->info & VDISK_CDROM) && |
| 384 | !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) { |
| 385 | return; |
| 386 | } |
| 387 | |
| 388 | if (!blkconf_blocksizes(conf, errp)) { |
| 389 | return; |
| 390 | } |
| 391 | |
| 392 | if (conf->discard_granularity == -1) { |
| 393 | conf->discard_granularity = conf->physical_block_size; |
| 394 | } |
| 395 | |
| 396 | if (blk_get_flags(blk) & BDRV_O_UNMAP) { |
| 397 | xen_device_backend_printf(xendev, "feature-discard", "%u", 1); |
| 398 | xen_device_backend_printf(xendev, "discard-granularity", "%u", |
| 399 | conf->discard_granularity); |
| 400 | xen_device_backend_printf(xendev, "discard-alignment", "%u", 0); |
| 401 | } |
| 402 | |
| 403 | xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1); |
| 404 | |
| 405 | if (qemu_xen_gnttab_can_map_multi()) { |
| 406 | xen_device_backend_printf(xendev, "max-ring-page-order", "%u", |
| 407 | blockdev->props.max_ring_page_order); |
| 408 | } |
| 409 | |
| 410 | xen_device_backend_printf(xendev, "info", "%u", blockdev->info); |
| 411 | xen_device_backend_printf(xendev, "mode", |
| 412 | (blockdev->info & VDISK_READONLY) ? "r" : "w"); |
| 413 | |
| 414 | xen_device_frontend_printf(xendev, "virtual-device", "%lu", |
| 415 | vdev->number); |
| 416 | xen_device_frontend_printf(xendev, "device-type", "%s", |
| 417 | blockdev->device_type); |
| 418 | |
| 419 | xen_device_backend_printf(xendev, "sector-size", "%u", |
| 420 | conf->logical_block_size); |
| 421 | |
| 422 | xen_block_set_size(blockdev); |
| 423 | |
| 424 | blockdev->dataplane = |
| 425 | xen_block_dataplane_create(xendev, blk, conf->logical_block_size, |
| 426 | blockdev->props.iothread); |
| 427 | |
| 428 | blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev); |
| 429 | } |
| 430 | |
| 431 | static void xen_block_frontend_changed(XenDevice *xendev, |
| 432 | enum xenbus_state frontend_state, |
| 433 | Error **errp) |
| 434 | { |
| 435 | ERRP_GUARD(); |
| 436 | enum xenbus_state backend_state = xen_device_backend_get_state(xendev); |
| 437 | |
| 438 | switch (frontend_state) { |
| 439 | case XenbusStateInitialised: |
| 440 | case XenbusStateConnected: |
| 441 | if (backend_state == XenbusStateConnected) { |
| 442 | break; |
| 443 | } |
| 444 | |
| 445 | xen_block_disconnect(xendev, errp); |
| 446 | if (*errp) { |
| 447 | break; |
| 448 | } |
| 449 | |
| 450 | xen_block_connect(xendev, errp); |
| 451 | if (*errp) { |
| 452 | break; |
| 453 | } |
| 454 | |
| 455 | xen_device_backend_set_state(xendev, XenbusStateConnected); |
| 456 | break; |
| 457 | |
| 458 | case XenbusStateClosing: |
| 459 | xen_device_backend_set_state(xendev, XenbusStateClosing); |
| 460 | break; |
| 461 | |
| 462 | case XenbusStateClosed: |
| 463 | case XenbusStateUnknown: |
| 464 | xen_block_disconnect(xendev, errp); |
| 465 | if (*errp) { |
| 466 | break; |
| 467 | } |
| 468 | |
| 469 | xen_device_backend_set_state(xendev, XenbusStateClosed); |
| 470 | break; |
| 471 | |
| 472 | default: |
| 473 | break; |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | static char *disk_to_vbd_name(unsigned int disk) |
| 478 | { |
| 479 | char *name, *prefix = (disk >= 26) ? |
| 480 | disk_to_vbd_name((disk / 26) - 1) : g_strdup(""); |
| 481 | |
| 482 | name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26); |
| 483 | g_free(prefix); |
| 484 | |
| 485 | return name; |
| 486 | } |
| 487 | |
| 488 | static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name, |
| 489 | void *opaque, Error **errp) |
| 490 | { |
| 491 | const Property *prop = opaque; |
| 492 | XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); |
| 493 | char *str; |
| 494 | |
| 495 | switch (vdev->type) { |
| 496 | case XEN_BLOCK_VDEV_TYPE_DP: |
| 497 | str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition); |
| 498 | break; |
| 499 | |
| 500 | case XEN_BLOCK_VDEV_TYPE_XVD: |
| 501 | case XEN_BLOCK_VDEV_TYPE_HD: |
| 502 | case XEN_BLOCK_VDEV_TYPE_SD: { |
| 503 | char *vbd_name = disk_to_vbd_name(vdev->disk); |
| 504 | |
| 505 | str = g_strdup_printf("%s%s%lu", |
| 506 | (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ? |
| 507 | "xvd" : |
| 508 | (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ? |
| 509 | "hd" : |
| 510 | "sd", |
| 511 | vbd_name, vdev->partition); |
| 512 | g_free(vbd_name); |
| 513 | break; |
| 514 | } |
| 515 | default: |
| 516 | error_setg(errp, "invalid vdev type"); |
| 517 | return; |
| 518 | } |
| 519 | |
| 520 | visit_type_str(v, name, &str, errp); |
| 521 | g_free(str); |
| 522 | } |
| 523 | |
| 524 | static int vbd_name_to_disk(const char *name, const char **endp, |
| 525 | unsigned long *disk) |
| 526 | { |
| 527 | unsigned int n = 0; |
| 528 | |
| 529 | while (*name != '\0') { |
| 530 | if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) { |
| 531 | break; |
| 532 | } |
| 533 | |
| 534 | n *= 26; |
| 535 | n += *name++ - 'a' + 1; |
| 536 | } |
| 537 | *endp = name; |
| 538 | |
| 539 | if (!n) { |
| 540 | return -1; |
| 541 | } |
| 542 | |
| 543 | *disk = n - 1; |
| 544 | |
| 545 | return 0; |
| 546 | } |
| 547 | |
| 548 | static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name, |
| 549 | void *opaque, Error **errp) |
| 550 | { |
| 551 | const Property *prop = opaque; |
| 552 | XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); |
| 553 | char *str, *p; |
| 554 | const char *end; |
| 555 | |
| 556 | if (!visit_type_str(v, name, &str, errp)) { |
| 557 | return; |
| 558 | } |
| 559 | |
| 560 | p = strchr(str, 'd'); |
| 561 | if (!p) { |
| 562 | goto invalid; |
| 563 | } |
| 564 | |
| 565 | *p++ = '\0'; |
| 566 | if (*str == '\0') { |
| 567 | vdev->type = XEN_BLOCK_VDEV_TYPE_DP; |
| 568 | } else if (strcmp(str, "xv") == 0) { |
| 569 | vdev->type = XEN_BLOCK_VDEV_TYPE_XVD; |
| 570 | } else if (strcmp(str, "h") == 0) { |
| 571 | vdev->type = XEN_BLOCK_VDEV_TYPE_HD; |
| 572 | } else if (strcmp(str, "s") == 0) { |
| 573 | vdev->type = XEN_BLOCK_VDEV_TYPE_SD; |
| 574 | } else { |
| 575 | goto invalid; |
| 576 | } |
| 577 | |
| 578 | if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) { |
| 579 | if (qemu_strtoul(p, &end, 10, &vdev->disk)) { |
| 580 | goto invalid; |
| 581 | } |
| 582 | |
| 583 | if (*end == 'p') { |
| 584 | if (*(++end) == '\0') { |
| 585 | goto invalid; |
| 586 | } |
| 587 | } |
| 588 | } else { |
| 589 | if (vbd_name_to_disk(p, &end, &vdev->disk)) { |
| 590 | goto invalid; |
| 591 | } |
| 592 | } |
| 593 | |
| 594 | if (*end != '\0') { |
| 595 | p = (char *)end; |
| 596 | |
| 597 | if (qemu_strtoul(p, &end, 10, &vdev->partition)) { |
| 598 | goto invalid; |
| 599 | } |
| 600 | |
| 601 | if (*end != '\0') { |
| 602 | goto invalid; |
| 603 | } |
| 604 | } else { |
| 605 | vdev->partition = 0; |
| 606 | } |
| 607 | |
| 608 | switch (vdev->type) { |
| 609 | case XEN_BLOCK_VDEV_TYPE_DP: |
| 610 | case XEN_BLOCK_VDEV_TYPE_XVD: |
| 611 | if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { |
| 612 | vdev->number = (XVDA_MAJOR << 8) | (vdev->disk << 4) | |
| 613 | vdev->partition; |
| 614 | } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) { |
| 615 | vdev->number = (XVDQ_MAJOR << 8) | (vdev->disk << 8) | |
| 616 | vdev->partition; |
| 617 | } else { |
| 618 | goto invalid; |
| 619 | } |
| 620 | break; |
| 621 | |
| 622 | case XEN_BLOCK_VDEV_TYPE_HD: |
| 623 | if ((vdev->disk == 0 || vdev->disk == 1) && |
| 624 | vdev->partition < (1 << 6)) { |
| 625 | vdev->number = (HDA_MAJOR << 8) | (vdev->disk << 6) | |
| 626 | vdev->partition; |
| 627 | } else if ((vdev->disk == 2 || vdev->disk == 3) && |
| 628 | vdev->partition < (1 << 6)) { |
| 629 | vdev->number = (HDC_MAJOR << 8) | ((vdev->disk - 2) << 6) | |
| 630 | vdev->partition; |
| 631 | } else { |
| 632 | goto invalid; |
| 633 | } |
| 634 | break; |
| 635 | |
| 636 | case XEN_BLOCK_VDEV_TYPE_SD: |
| 637 | if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { |
| 638 | vdev->number = (SDA_MAJOR << 8) | (vdev->disk << 4) | |
| 639 | vdev->partition; |
| 640 | } else { |
| 641 | goto invalid; |
| 642 | } |
| 643 | break; |
| 644 | |
| 645 | default: |
| 646 | goto invalid; |
| 647 | } |
| 648 | |
| 649 | g_free(str); |
| 650 | return; |
| 651 | |
| 652 | invalid: |
| 653 | error_setg(errp, "invalid virtual disk specifier"); |
| 654 | |
| 655 | vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID; |
| 656 | g_free(str); |
| 657 | } |
| 658 | |
| 659 | /* |
| 660 | * This property deals with 'vdev' names adhering to the Xen VBD naming |
| 661 | * scheme described in: |
| 662 | * |
| 663 | * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html |
| 664 | */ |
| 665 | static const PropertyInfo xen_block_prop_vdev = { |
| 666 | .type = "str", |
| 667 | .description = "Virtual Disk specifier (d*p*/xvd*/hd*/sd*)", |
| 668 | .get = xen_block_get_vdev, |
| 669 | .set = xen_block_set_vdev, |
| 670 | }; |
| 671 | |
| 672 | static const Property xen_block_props[] = { |
| 673 | DEFINE_PROP("vdev", XenBlockDevice, props.vdev, |
| 674 | xen_block_prop_vdev, XenBlockVdev), |
| 675 | DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf), |
| 676 | DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice, |
| 677 | props.max_ring_page_order, 4), |
| 678 | DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread, |
| 679 | TYPE_IOTHREAD, IOThread *), |
| 680 | }; |
| 681 | |
| 682 | static void xen_block_class_init(ObjectClass *class, const void *data) |
| 683 | { |
| 684 | DeviceClass *dev_class = DEVICE_CLASS(class); |
| 685 | XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); |
| 686 | |
| 687 | xendev_class->backend = "qdisk"; |
| 688 | xendev_class->device = "vbd"; |
| 689 | xendev_class->get_name = xen_block_get_name; |
| 690 | xendev_class->realize = xen_block_realize; |
| 691 | xendev_class->frontend_changed = xen_block_frontend_changed; |
| 692 | xendev_class->unrealize = xen_block_unrealize; |
| 693 | |
| 694 | device_class_set_props(dev_class, xen_block_props); |
| 695 | } |
| 696 | |
| 697 | static const TypeInfo xen_block_type_info = { |
| 698 | .name = TYPE_XEN_BLOCK_DEVICE, |
| 699 | .parent = TYPE_XEN_DEVICE, |
| 700 | .instance_size = sizeof(XenBlockDevice), |
| 701 | .abstract = true, |
| 702 | .class_size = sizeof(XenBlockDeviceClass), |
| 703 | .class_init = xen_block_class_init, |
| 704 | }; |
| 705 | |
| 706 | static void xen_disk_unrealize(XenBlockDevice *blockdev) |
| 707 | { |
| 708 | trace_xen_disk_unrealize(); |
| 709 | } |
| 710 | |
| 711 | static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp) |
| 712 | { |
| 713 | BlockConf *conf = &blockdev->props.conf; |
| 714 | |
| 715 | trace_xen_disk_realize(); |
| 716 | |
| 717 | blockdev->device_type = "disk"; |
| 718 | |
| 719 | if (!conf->blk) { |
| 720 | error_setg(errp, "drive property not set"); |
| 721 | return; |
| 722 | } |
| 723 | |
| 724 | blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY; |
| 725 | } |
| 726 | |
| 727 | static void xen_disk_class_init(ObjectClass *class, const void *data) |
| 728 | { |
| 729 | DeviceClass *dev_class = DEVICE_CLASS(class); |
| 730 | XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); |
| 731 | |
| 732 | blockdev_class->realize = xen_disk_realize; |
| 733 | blockdev_class->unrealize = xen_disk_unrealize; |
| 734 | |
| 735 | dev_class->desc = "Xen Disk Device"; |
| 736 | } |
| 737 | |
| 738 | static const TypeInfo xen_disk_type_info = { |
| 739 | .name = TYPE_XEN_DISK_DEVICE, |
| 740 | .parent = TYPE_XEN_BLOCK_DEVICE, |
| 741 | .instance_size = sizeof(XenDiskDevice), |
| 742 | .class_init = xen_disk_class_init, |
| 743 | }; |
| 744 | |
| 745 | static void xen_cdrom_unrealize(XenBlockDevice *blockdev) |
| 746 | { |
| 747 | trace_xen_cdrom_unrealize(); |
| 748 | } |
| 749 | |
| 750 | static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp) |
| 751 | { |
| 752 | BlockConf *conf = &blockdev->props.conf; |
| 753 | |
| 754 | trace_xen_cdrom_realize(); |
| 755 | |
| 756 | blockdev->device_type = "cdrom"; |
| 757 | |
| 758 | if (!conf->blk) { |
| 759 | int rc; |
| 760 | |
| 761 | /* Set up an empty drive */ |
| 762 | conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); |
| 763 | |
| 764 | rc = blk_attach_dev(conf->blk, DEVICE(blockdev)); |
| 765 | if (!rc) { |
| 766 | error_setg_errno(errp, -rc, "failed to create drive"); |
| 767 | return; |
| 768 | } |
| 769 | } |
| 770 | |
| 771 | blockdev->info = VDISK_READONLY | VDISK_CDROM; |
| 772 | } |
| 773 | |
| 774 | static void xen_cdrom_class_init(ObjectClass *class, const void *data) |
| 775 | { |
| 776 | DeviceClass *dev_class = DEVICE_CLASS(class); |
| 777 | XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); |
| 778 | |
| 779 | blockdev_class->realize = xen_cdrom_realize; |
| 780 | blockdev_class->unrealize = xen_cdrom_unrealize; |
| 781 | |
| 782 | dev_class->desc = "Xen CD-ROM Device"; |
| 783 | } |
| 784 | |
| 785 | static const TypeInfo xen_cdrom_type_info = { |
| 786 | .name = TYPE_XEN_CDROM_DEVICE, |
| 787 | .parent = TYPE_XEN_BLOCK_DEVICE, |
| 788 | .instance_size = sizeof(XenCDRomDevice), |
| 789 | .class_init = xen_cdrom_class_init, |
| 790 | }; |
| 791 | |
| 792 | static void xen_block_register_types(void) |
| 793 | { |
| 794 | type_register_static(&xen_block_type_info); |
| 795 | type_register_static(&xen_disk_type_info); |
| 796 | type_register_static(&xen_cdrom_type_info); |
| 797 | } |
| 798 | |
| 799 | type_init(xen_block_register_types) |
| 800 | |
| 801 | static void xen_block_blockdev_del(const char *node_name, Error **errp) |
| 802 | { |
| 803 | trace_xen_block_blockdev_del(node_name); |
| 804 | |
| 805 | qmp_blockdev_del(node_name, errp); |
| 806 | } |
| 807 | |
| 808 | static char *xen_block_blockdev_add(const char *id, QDict *qdict, |
| 809 | Error **errp) |
| 810 | { |
| 811 | ERRP_GUARD(); |
| 812 | const char *driver = qdict_get_try_str(qdict, "driver"); |
| 813 | BlockdevOptions *options = NULL; |
| 814 | char *node_name; |
| 815 | Visitor *v; |
| 816 | |
| 817 | if (!driver) { |
| 818 | error_setg(errp, "no 'driver' parameter"); |
| 819 | return NULL; |
| 820 | } |
| 821 | |
| 822 | node_name = g_strdup_printf("%s-%s", id, driver); |
| 823 | qdict_put_str(qdict, "node-name", node_name); |
| 824 | |
| 825 | trace_xen_block_blockdev_add(node_name); |
| 826 | |
| 827 | v = qobject_input_visitor_new(QOBJECT(qdict)); |
| 828 | visit_type_BlockdevOptions(v, NULL, &options, errp); |
| 829 | visit_free(v); |
| 830 | if (!options) { |
| 831 | goto fail; |
| 832 | } |
| 833 | |
| 834 | qmp_blockdev_add(options, errp); |
| 835 | |
| 836 | if (*errp) { |
| 837 | goto fail; |
| 838 | } |
| 839 | |
| 840 | qapi_free_BlockdevOptions(options); |
| 841 | |
| 842 | return node_name; |
| 843 | |
| 844 | fail: |
| 845 | if (options) { |
| 846 | qapi_free_BlockdevOptions(options); |
| 847 | } |
| 848 | g_free(node_name); |
| 849 | |
| 850 | return NULL; |
| 851 | } |
| 852 | |
| 853 | static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp) |
| 854 | { |
| 855 | ERRP_GUARD(); |
| 856 | char *node_name = drive->node_name; |
| 857 | |
| 858 | if (node_name) { |
| 859 | xen_block_blockdev_del(node_name, errp); |
| 860 | if (*errp) { |
| 861 | return; |
| 862 | } |
| 863 | g_free(node_name); |
| 864 | drive->node_name = NULL; |
| 865 | } |
| 866 | g_free(drive->id); |
| 867 | g_free(drive); |
| 868 | } |
| 869 | |
| 870 | static XenBlockDrive *xen_block_drive_create(const char *id, |
| 871 | const char *device_type, |
| 872 | QDict *opts, Error **errp) |
| 873 | { |
| 874 | ERRP_GUARD(); |
| 875 | const char *params = qdict_get_try_str(opts, "params"); |
| 876 | const char *mode = qdict_get_try_str(opts, "mode"); |
| 877 | const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe"); |
| 878 | const char *discard_enable = qdict_get_try_str(opts, "discard-enable"); |
| 879 | char *driver = NULL; |
| 880 | char *filename = NULL; |
| 881 | XenBlockDrive *drive = NULL; |
| 882 | QDict *file_layer; |
| 883 | QDict *driver_layer; |
| 884 | struct stat st; |
| 885 | int rc; |
| 886 | char **v; |
| 887 | |
| 888 | if (!params) { |
| 889 | error_setg(errp, "no params"); |
| 890 | return NULL; |
| 891 | } |
| 892 | |
| 893 | v = g_strsplit(params, ":", 2); |
| 894 | if (v[1] == NULL) { |
| 895 | filename = g_strdup(v[0]); |
| 896 | driver = g_strdup("raw"); |
| 897 | } else { |
| 898 | if (strcmp(v[0], "aio") == 0) { |
| 899 | driver = g_strdup("raw"); |
| 900 | } else if (strcmp(v[0], "vhd") == 0) { |
| 901 | driver = g_strdup("vpc"); |
| 902 | } else { |
| 903 | driver = g_strdup(v[0]); |
| 904 | } |
| 905 | filename = g_strdup(v[1]); |
| 906 | } |
| 907 | |
| 908 | g_strfreev(v); |
| 909 | |
| 910 | drive = g_new0(XenBlockDrive, 1); |
| 911 | drive->id = g_strdup(id); |
| 912 | |
| 913 | rc = stat(filename, &st); |
| 914 | if (rc) { |
| 915 | error_setg_errno(errp, errno, "Could not stat file '%s'", filename); |
| 916 | goto done; |
| 917 | } |
| 918 | |
| 919 | file_layer = qdict_new(); |
| 920 | driver_layer = qdict_new(); |
| 921 | |
| 922 | if (S_ISBLK(st.st_mode)) { |
| 923 | qdict_put_str(file_layer, "driver", "host_device"); |
| 924 | } else { |
| 925 | qdict_put_str(file_layer, "driver", "file"); |
| 926 | } |
| 927 | |
| 928 | qdict_put_str(file_layer, "filename", filename); |
| 929 | |
| 930 | if (mode && *mode != 'w') { |
| 931 | qdict_put_bool(file_layer, "read-only", true); |
| 932 | } |
| 933 | |
| 934 | if (direct_io_safe) { |
| 935 | unsigned long value; |
| 936 | |
| 937 | if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) { |
| 938 | QDict *cache_qdict = qdict_new(); |
| 939 | |
| 940 | qdict_put_bool(cache_qdict, "direct", true); |
| 941 | qdict_put(file_layer, "cache", cache_qdict); |
| 942 | |
| 943 | qdict_put_str(file_layer, "aio", "native"); |
| 944 | } |
| 945 | } |
| 946 | |
| 947 | if (discard_enable) { |
| 948 | unsigned long value; |
| 949 | |
| 950 | if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) { |
| 951 | qdict_put_str(file_layer, "discard", "unmap"); |
| 952 | qdict_put_str(driver_layer, "discard", "unmap"); |
| 953 | } |
| 954 | } |
| 955 | |
| 956 | /* |
| 957 | * It is necessary to turn file locking off as an emulated device |
| 958 | * may have already opened the same image file. |
| 959 | */ |
| 960 | qdict_put_str(file_layer, "locking", "off"); |
| 961 | |
| 962 | qdict_put_str(driver_layer, "driver", driver); |
| 963 | |
| 964 | qdict_put(driver_layer, "file", file_layer); |
| 965 | |
| 966 | g_assert(!drive->node_name); |
| 967 | drive->node_name = xen_block_blockdev_add(drive->id, driver_layer, |
| 968 | errp); |
| 969 | |
| 970 | qobject_unref(driver_layer); |
| 971 | |
| 972 | done: |
| 973 | g_free(filename); |
| 974 | g_free(driver); |
| 975 | if (*errp) { |
| 976 | xen_block_drive_destroy(drive, NULL); |
| 977 | return NULL; |
| 978 | } |
| 979 | |
| 980 | return drive; |
| 981 | } |
| 982 | |
| 983 | static const char *xen_block_drive_get_node_name(XenBlockDrive *drive) |
| 984 | { |
| 985 | return drive->node_name ? drive->node_name : ""; |
| 986 | } |
| 987 | |
| 988 | static void xen_block_iothread_destroy(XenBlockIOThread *iothread, |
| 989 | Error **errp) |
| 990 | { |
| 991 | qmp_object_del(iothread->id, errp); |
| 992 | |
| 993 | g_free(iothread->id); |
| 994 | g_free(iothread); |
| 995 | } |
| 996 | |
| 997 | static XenBlockIOThread *xen_block_iothread_create(const char *id, |
| 998 | Error **errp) |
| 999 | { |
| 1000 | ERRP_GUARD(); |
| 1001 | XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1); |
| 1002 | ObjectOptions *opts; |
| 1003 | |
| 1004 | iothread->id = g_strdup(id); |
| 1005 | |
| 1006 | opts = g_new(ObjectOptions, 1); |
| 1007 | *opts = (ObjectOptions) { |
| 1008 | .qom_type = OBJECT_TYPE_IOTHREAD, |
| 1009 | .id = g_strdup(id), |
| 1010 | }; |
| 1011 | qmp_object_add(opts, errp); |
| 1012 | qapi_free_ObjectOptions(opts); |
| 1013 | |
| 1014 | if (*errp) { |
| 1015 | g_free(iothread->id); |
| 1016 | g_free(iothread); |
| 1017 | return NULL; |
| 1018 | } |
| 1019 | |
| 1020 | return iothread; |
| 1021 | } |
| 1022 | |
| 1023 | static void xen_block_device_create(XenBackendInstance *backend, |
| 1024 | QDict *opts, Error **errp) |
| 1025 | { |
| 1026 | ERRP_GUARD(); |
| 1027 | XenBus *xenbus = xen_backend_get_bus(backend); |
| 1028 | const char *name = xen_backend_get_name(backend); |
| 1029 | unsigned long number; |
| 1030 | const char *vdev, *device_type; |
| 1031 | XenBlockDrive *drive = NULL; |
| 1032 | XenBlockIOThread *iothread = NULL; |
| 1033 | XenDevice *xendev = NULL; |
| 1034 | const char *type; |
| 1035 | XenBlockDevice *blockdev; |
| 1036 | |
| 1037 | if (qemu_strtoul(name, NULL, 10, &number)) { |
| 1038 | error_setg(errp, "failed to parse name '%s'", name); |
| 1039 | goto fail; |
| 1040 | } |
| 1041 | |
| 1042 | trace_xen_block_device_create(number); |
| 1043 | |
| 1044 | vdev = qdict_get_try_str(opts, "dev"); |
| 1045 | if (!vdev) { |
| 1046 | error_setg(errp, "no dev parameter"); |
| 1047 | goto fail; |
| 1048 | } |
| 1049 | |
| 1050 | device_type = qdict_get_try_str(opts, "device-type"); |
| 1051 | if (!device_type) { |
| 1052 | error_setg(errp, "no device-type parameter"); |
| 1053 | goto fail; |
| 1054 | } |
| 1055 | |
| 1056 | if (!strcmp(device_type, "disk")) { |
| 1057 | type = TYPE_XEN_DISK_DEVICE; |
| 1058 | } else if (!strcmp(device_type, "cdrom")) { |
| 1059 | type = TYPE_XEN_CDROM_DEVICE; |
| 1060 | } else { |
| 1061 | error_setg(errp, "invalid device-type parameter '%s'", device_type); |
| 1062 | goto fail; |
| 1063 | } |
| 1064 | |
| 1065 | drive = xen_block_drive_create(vdev, device_type, opts, errp); |
| 1066 | if (!drive) { |
| 1067 | error_prepend(errp, "failed to create drive: "); |
| 1068 | goto fail; |
| 1069 | } |
| 1070 | |
| 1071 | iothread = xen_block_iothread_create(vdev, errp); |
| 1072 | if (*errp) { |
| 1073 | error_prepend(errp, "failed to create iothread: "); |
| 1074 | goto fail; |
| 1075 | } |
| 1076 | |
| 1077 | xendev = XEN_DEVICE(qdev_new(type)); |
| 1078 | blockdev = XEN_BLOCK_DEVICE(xendev); |
| 1079 | |
| 1080 | if (!object_property_set_str(OBJECT(xendev), "vdev", vdev, |
| 1081 | errp)) { |
| 1082 | error_prepend(errp, "failed to set 'vdev': "); |
| 1083 | goto fail; |
| 1084 | } |
| 1085 | |
| 1086 | if (!object_property_set_str(OBJECT(xendev), "drive", |
| 1087 | xen_block_drive_get_node_name(drive), |
| 1088 | errp)) { |
| 1089 | error_prepend(errp, "failed to set 'drive': "); |
| 1090 | goto fail; |
| 1091 | } |
| 1092 | |
| 1093 | if (!object_property_set_str(OBJECT(xendev), "iothread", iothread->id, |
| 1094 | errp)) { |
| 1095 | error_prepend(errp, "failed to set 'iothread': "); |
| 1096 | goto fail; |
| 1097 | } |
| 1098 | |
| 1099 | blockdev->iothread = iothread; |
| 1100 | blockdev->drive = drive; |
| 1101 | |
| 1102 | if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { |
| 1103 | error_prepend(errp, "realization of device %s failed: ", type); |
| 1104 | goto fail; |
| 1105 | } |
| 1106 | |
| 1107 | xen_backend_set_device(backend, xendev); |
| 1108 | return; |
| 1109 | |
| 1110 | fail: |
| 1111 | if (xendev) { |
| 1112 | object_unparent(OBJECT(xendev)); |
| 1113 | } |
| 1114 | |
| 1115 | if (iothread) { |
| 1116 | xen_block_iothread_destroy(iothread, NULL); |
| 1117 | } |
| 1118 | |
| 1119 | if (drive) { |
| 1120 | xen_block_drive_destroy(drive, NULL); |
| 1121 | } |
| 1122 | } |
| 1123 | |
| 1124 | static void xen_block_device_destroy(XenBackendInstance *backend, |
| 1125 | Error **errp) |
| 1126 | { |
| 1127 | ERRP_GUARD(); |
| 1128 | XenDevice *xendev = xen_backend_get_device(backend); |
| 1129 | XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); |
| 1130 | XenBlockVdev *vdev = &blockdev->props.vdev; |
| 1131 | XenBlockDrive *drive = blockdev->drive; |
| 1132 | XenBlockIOThread *iothread = blockdev->iothread; |
| 1133 | |
| 1134 | trace_xen_block_device_destroy(vdev->number); |
| 1135 | |
| 1136 | object_unparent(OBJECT(xendev)); |
| 1137 | |
| 1138 | /* |
| 1139 | * Drain all pending RCU callbacks as object_unparent() frees `xendev' |
| 1140 | * in a RCU callback. |
| 1141 | * And due to the property "drive" still existing in `xendev', we |
| 1142 | * can't destroy the XenBlockDrive associated with `xendev' with |
| 1143 | * xen_block_drive_destroy() below. |
| 1144 | */ |
| 1145 | drain_call_rcu(); |
| 1146 | |
| 1147 | if (iothread) { |
| 1148 | xen_block_iothread_destroy(iothread, errp); |
| 1149 | if (*errp) { |
| 1150 | error_prepend(errp, "failed to destroy iothread: "); |
| 1151 | return; |
| 1152 | } |
| 1153 | } |
| 1154 | |
| 1155 | if (drive) { |
| 1156 | xen_block_drive_destroy(drive, errp); |
| 1157 | if (*errp) { |
| 1158 | error_prepend(errp, "failed to destroy drive: "); |
| 1159 | return; |
| 1160 | } |
| 1161 | } |
| 1162 | } |
| 1163 | |
| 1164 | static const XenBackendInfo xen_block_backend_info = { |
| 1165 | .type = "qdisk", |
| 1166 | .create = xen_block_device_create, |
| 1167 | .destroy = xen_block_device_destroy, |
| 1168 | }; |
| 1169 | |
| 1170 | static void xen_block_register_backend(void) |
| 1171 | { |
| 1172 | xen_backend_register(&xen_block_backend_info); |
| 1173 | } |
| 1174 | |
| 1175 | xen_backend_init(xen_block_register_backend); |