xen-block.c (28496B)
1 /* 2 * Copyright (c) 2018 Citrix Systems Inc. 3 * 4 * This work is licensed under the terms of the GNU GPL, version 2 or later. 5 * See the COPYING file in the top-level directory. 6 */ 7 8 #include "qemu/osdep.h" 9 #include "qemu/cutils.h" 10 #include "qemu/main-loop.h" 11 #include "qemu/module.h" 12 #include "qemu/option.h" 13 #include "qapi/error.h" 14 #include "qapi/qapi-commands-block-core.h" 15 #include "qapi/qapi-commands-qom.h" 16 #include "qapi/qapi-visit-block-core.h" 17 #include "qapi/qobject-input-visitor.h" 18 #include "qapi/visitor.h" 19 #include "qapi/qmp/qdict.h" 20 #include "qapi/qmp/qstring.h" 21 #include "qom/object_interfaces.h" 22 #include "hw/xen/xen_common.h" 23 #include "hw/block/xen_blkif.h" 24 #include "hw/qdev-properties.h" 25 #include "hw/xen/xen-block.h" 26 #include "hw/xen/xen-backend.h" 27 #include "sysemu/blockdev.h" 28 #include "sysemu/block-backend.h" 29 #include "sysemu/iothread.h" 30 #include "dataplane/xen-block.h" 31 #include "trace.h" 32 33 static char *xen_block_get_name(XenDevice *xendev, Error **errp) 34 { 35 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 36 XenBlockVdev *vdev = &blockdev->props.vdev; 37 38 return g_strdup_printf("%lu", vdev->number); 39 } 40 41 static void xen_block_disconnect(XenDevice *xendev, Error **errp) 42 { 43 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 44 const char *type = object_get_typename(OBJECT(blockdev)); 45 XenBlockVdev *vdev = &blockdev->props.vdev; 46 47 trace_xen_block_disconnect(type, vdev->disk, vdev->partition); 48 49 xen_block_dataplane_stop(blockdev->dataplane); 50 } 51 52 static void xen_block_connect(XenDevice *xendev, Error **errp) 53 { 54 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 55 const char *type = object_get_typename(OBJECT(blockdev)); 56 XenBlockVdev *vdev = &blockdev->props.vdev; 57 BlockConf *conf = &blockdev->props.conf; 58 unsigned int feature_large_sector_size; 59 unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol; 60 char *str; 61 62 trace_xen_block_connect(type, vdev->disk, vdev->partition); 63 64 if (xen_device_frontend_scanf(xendev, "feature-large-sector-size", "%u", 65 &feature_large_sector_size) != 1) { 66 feature_large_sector_size = 0; 67 } 68 69 if (feature_large_sector_size != 1 && 70 conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) { 71 error_setg(errp, "logical_block_size != %u not supported by frontend", 72 XEN_BLKIF_SECTOR_SIZE); 73 return; 74 } 75 76 if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u", 77 &order) != 1) { 78 nr_ring_ref = 1; 79 ring_ref = g_new(unsigned int, nr_ring_ref); 80 81 if (xen_device_frontend_scanf(xendev, "ring-ref", "%u", 82 &ring_ref[0]) != 1) { 83 error_setg(errp, "failed to read ring-ref"); 84 g_free(ring_ref); 85 return; 86 } 87 } else if (order <= blockdev->props.max_ring_page_order) { 88 unsigned int i; 89 90 nr_ring_ref = 1 << order; 91 ring_ref = g_new(unsigned int, nr_ring_ref); 92 93 for (i = 0; i < nr_ring_ref; i++) { 94 const char *key = g_strdup_printf("ring-ref%u", i); 95 96 if (xen_device_frontend_scanf(xendev, key, "%u", 97 &ring_ref[i]) != 1) { 98 error_setg(errp, "failed to read %s", key); 99 g_free((gpointer)key); 100 g_free(ring_ref); 101 return; 102 } 103 104 g_free((gpointer)key); 105 } 106 } else { 107 error_setg(errp, "invalid ring-page-order (%d)", order); 108 return; 109 } 110 111 if (xen_device_frontend_scanf(xendev, "event-channel", "%u", 112 &event_channel) != 1) { 113 error_setg(errp, "failed to read event-channel"); 114 g_free(ring_ref); 115 return; 116 } 117 118 if (xen_device_frontend_scanf(xendev, "protocol", "%ms", 119 &str) != 1) { 120 protocol = BLKIF_PROTOCOL_NATIVE; 121 } else { 122 if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) { 123 protocol = BLKIF_PROTOCOL_X86_32; 124 } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) { 125 protocol = BLKIF_PROTOCOL_X86_64; 126 } else { 127 protocol = BLKIF_PROTOCOL_NATIVE; 128 } 129 130 free(str); 131 } 132 133 xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref, 134 event_channel, protocol, errp); 135 136 g_free(ring_ref); 137 } 138 139 static void xen_block_unrealize(XenDevice *xendev) 140 { 141 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 142 XenBlockDeviceClass *blockdev_class = 143 XEN_BLOCK_DEVICE_GET_CLASS(xendev); 144 const char *type = object_get_typename(OBJECT(blockdev)); 145 XenBlockVdev *vdev = &blockdev->props.vdev; 146 147 if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { 148 return; 149 } 150 151 trace_xen_block_unrealize(type, vdev->disk, vdev->partition); 152 153 /* Disconnect from the frontend in case this has not already happened */ 154 xen_block_disconnect(xendev, NULL); 155 156 xen_block_dataplane_destroy(blockdev->dataplane); 157 blockdev->dataplane = NULL; 158 159 if (blockdev_class->unrealize) { 160 blockdev_class->unrealize(blockdev); 161 } 162 } 163 164 static void xen_block_set_size(XenBlockDevice *blockdev) 165 { 166 const char *type = object_get_typename(OBJECT(blockdev)); 167 XenBlockVdev *vdev = &blockdev->props.vdev; 168 BlockConf *conf = &blockdev->props.conf; 169 int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size; 170 XenDevice *xendev = XEN_DEVICE(blockdev); 171 172 trace_xen_block_size(type, vdev->disk, vdev->partition, sectors); 173 174 xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors); 175 } 176 177 static void xen_block_resize_cb(void *opaque) 178 { 179 XenBlockDevice *blockdev = opaque; 180 XenDevice *xendev = XEN_DEVICE(blockdev); 181 enum xenbus_state state = xen_device_backend_get_state(xendev); 182 183 xen_block_set_size(blockdev); 184 185 /* 186 * Mimic the behaviour of Linux xen-blkback and re-write the state 187 * to trigger the frontend watch. 188 */ 189 xen_device_backend_printf(xendev, "state", "%u", state); 190 } 191 192 static const BlockDevOps xen_block_dev_ops = { 193 .resize_cb = xen_block_resize_cb, 194 }; 195 196 static void xen_block_realize(XenDevice *xendev, Error **errp) 197 { 198 ERRP_GUARD(); 199 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 200 XenBlockDeviceClass *blockdev_class = 201 XEN_BLOCK_DEVICE_GET_CLASS(xendev); 202 const char *type = object_get_typename(OBJECT(blockdev)); 203 XenBlockVdev *vdev = &blockdev->props.vdev; 204 BlockConf *conf = &blockdev->props.conf; 205 BlockBackend *blk = conf->blk; 206 207 if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { 208 error_setg(errp, "vdev property not set"); 209 return; 210 } 211 212 trace_xen_block_realize(type, vdev->disk, vdev->partition); 213 214 if (blockdev_class->realize) { 215 blockdev_class->realize(blockdev, errp); 216 if (*errp) { 217 return; 218 } 219 } 220 221 /* 222 * The blkif protocol does not deal with removable media, so it must 223 * always be present, even for CDRom devices. 224 */ 225 assert(blk); 226 if (!blk_is_inserted(blk)) { 227 error_setg(errp, "device needs media, but drive is empty"); 228 return; 229 } 230 231 if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY, 232 true, errp)) { 233 return; 234 } 235 236 if (!(blockdev->info & VDISK_CDROM) && 237 !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) { 238 return; 239 } 240 241 if (!blkconf_blocksizes(conf, errp)) { 242 return; 243 } 244 245 blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev); 246 247 if (conf->discard_granularity == -1) { 248 conf->discard_granularity = conf->physical_block_size; 249 } 250 251 if (blk_get_flags(blk) & BDRV_O_UNMAP) { 252 xen_device_backend_printf(xendev, "feature-discard", "%u", 1); 253 xen_device_backend_printf(xendev, "discard-granularity", "%u", 254 conf->discard_granularity); 255 xen_device_backend_printf(xendev, "discard-alignment", "%u", 0); 256 } 257 258 xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1); 259 xen_device_backend_printf(xendev, "max-ring-page-order", "%u", 260 blockdev->props.max_ring_page_order); 261 xen_device_backend_printf(xendev, "info", "%u", blockdev->info); 262 263 xen_device_frontend_printf(xendev, "virtual-device", "%lu", 264 vdev->number); 265 xen_device_frontend_printf(xendev, "device-type", "%s", 266 blockdev->device_type); 267 268 xen_device_backend_printf(xendev, "sector-size", "%u", 269 conf->logical_block_size); 270 271 xen_block_set_size(blockdev); 272 273 blockdev->dataplane = 274 xen_block_dataplane_create(xendev, blk, conf->logical_block_size, 275 blockdev->props.iothread); 276 } 277 278 static void xen_block_frontend_changed(XenDevice *xendev, 279 enum xenbus_state frontend_state, 280 Error **errp) 281 { 282 ERRP_GUARD(); 283 enum xenbus_state backend_state = xen_device_backend_get_state(xendev); 284 285 switch (frontend_state) { 286 case XenbusStateInitialised: 287 case XenbusStateConnected: 288 if (backend_state == XenbusStateConnected) { 289 break; 290 } 291 292 xen_block_disconnect(xendev, errp); 293 if (*errp) { 294 break; 295 } 296 297 xen_block_connect(xendev, errp); 298 if (*errp) { 299 break; 300 } 301 302 xen_device_backend_set_state(xendev, XenbusStateConnected); 303 break; 304 305 case XenbusStateClosing: 306 xen_device_backend_set_state(xendev, XenbusStateClosing); 307 break; 308 309 case XenbusStateClosed: 310 case XenbusStateUnknown: 311 xen_block_disconnect(xendev, errp); 312 if (*errp) { 313 break; 314 } 315 316 xen_device_backend_set_state(xendev, XenbusStateClosed); 317 break; 318 319 default: 320 break; 321 } 322 } 323 324 static char *disk_to_vbd_name(unsigned int disk) 325 { 326 char *name, *prefix = (disk >= 26) ? 327 disk_to_vbd_name((disk / 26) - 1) : g_strdup(""); 328 329 name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26); 330 g_free(prefix); 331 332 return name; 333 } 334 335 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name, 336 void *opaque, Error **errp) 337 { 338 Property *prop = opaque; 339 XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); 340 char *str; 341 342 switch (vdev->type) { 343 case XEN_BLOCK_VDEV_TYPE_DP: 344 str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition); 345 break; 346 347 case XEN_BLOCK_VDEV_TYPE_XVD: 348 case XEN_BLOCK_VDEV_TYPE_HD: 349 case XEN_BLOCK_VDEV_TYPE_SD: { 350 char *name = disk_to_vbd_name(vdev->disk); 351 352 str = g_strdup_printf("%s%s%lu", 353 (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ? 354 "xvd" : 355 (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ? 356 "hd" : 357 "sd", 358 name, vdev->partition); 359 g_free(name); 360 break; 361 } 362 default: 363 error_setg(errp, "invalid vdev type"); 364 return; 365 } 366 367 visit_type_str(v, name, &str, errp); 368 g_free(str); 369 } 370 371 static int vbd_name_to_disk(const char *name, const char **endp, 372 unsigned long *disk) 373 { 374 unsigned int n = 0; 375 376 while (*name != '\0') { 377 if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) { 378 break; 379 } 380 381 n *= 26; 382 n += *name++ - 'a' + 1; 383 } 384 *endp = name; 385 386 if (!n) { 387 return -1; 388 } 389 390 *disk = n - 1; 391 392 return 0; 393 } 394 395 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name, 396 void *opaque, Error **errp) 397 { 398 Property *prop = opaque; 399 XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); 400 char *str, *p; 401 const char *end; 402 403 if (!visit_type_str(v, name, &str, errp)) { 404 return; 405 } 406 407 p = strchr(str, 'd'); 408 if (!p) { 409 goto invalid; 410 } 411 412 *p++ = '\0'; 413 if (*str == '\0') { 414 vdev->type = XEN_BLOCK_VDEV_TYPE_DP; 415 } else if (strcmp(str, "xv") == 0) { 416 vdev->type = XEN_BLOCK_VDEV_TYPE_XVD; 417 } else if (strcmp(str, "h") == 0) { 418 vdev->type = XEN_BLOCK_VDEV_TYPE_HD; 419 } else if (strcmp(str, "s") == 0) { 420 vdev->type = XEN_BLOCK_VDEV_TYPE_SD; 421 } else { 422 goto invalid; 423 } 424 425 if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) { 426 if (qemu_strtoul(p, &end, 10, &vdev->disk)) { 427 goto invalid; 428 } 429 430 if (*end == 'p') { 431 if (*(++end) == '\0') { 432 goto invalid; 433 } 434 } 435 } else { 436 if (vbd_name_to_disk(p, &end, &vdev->disk)) { 437 goto invalid; 438 } 439 } 440 441 if (*end != '\0') { 442 p = (char *)end; 443 444 if (qemu_strtoul(p, &end, 10, &vdev->partition)) { 445 goto invalid; 446 } 447 448 if (*end != '\0') { 449 goto invalid; 450 } 451 } else { 452 vdev->partition = 0; 453 } 454 455 switch (vdev->type) { 456 case XEN_BLOCK_VDEV_TYPE_DP: 457 case XEN_BLOCK_VDEV_TYPE_XVD: 458 if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { 459 vdev->number = (202 << 8) | (vdev->disk << 4) | 460 vdev->partition; 461 } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) { 462 vdev->number = (1 << 28) | (vdev->disk << 8) | 463 vdev->partition; 464 } else { 465 goto invalid; 466 } 467 break; 468 469 case XEN_BLOCK_VDEV_TYPE_HD: 470 if ((vdev->disk == 0 || vdev->disk == 1) && 471 vdev->partition < (1 << 6)) { 472 vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition; 473 } else if ((vdev->disk == 2 || vdev->disk == 3) && 474 vdev->partition < (1 << 6)) { 475 vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) | 476 vdev->partition; 477 } else { 478 goto invalid; 479 } 480 break; 481 482 case XEN_BLOCK_VDEV_TYPE_SD: 483 if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { 484 vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition; 485 } else { 486 goto invalid; 487 } 488 break; 489 490 default: 491 goto invalid; 492 } 493 494 g_free(str); 495 return; 496 497 invalid: 498 error_setg(errp, "invalid virtual disk specifier"); 499 500 vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID; 501 g_free(str); 502 } 503 504 /* 505 * This property deals with 'vdev' names adhering to the Xen VBD naming 506 * scheme described in: 507 * 508 * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html 509 */ 510 const PropertyInfo xen_block_prop_vdev = { 511 .name = "str", 512 .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*", 513 .get = xen_block_get_vdev, 514 .set = xen_block_set_vdev, 515 }; 516 517 static Property xen_block_props[] = { 518 DEFINE_PROP("vdev", XenBlockDevice, props.vdev, 519 xen_block_prop_vdev, XenBlockVdev), 520 DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf), 521 DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice, 522 props.max_ring_page_order, 4), 523 DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread, 524 TYPE_IOTHREAD, IOThread *), 525 DEFINE_PROP_END_OF_LIST() 526 }; 527 528 static void xen_block_class_init(ObjectClass *class, void *data) 529 { 530 DeviceClass *dev_class = DEVICE_CLASS(class); 531 XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); 532 533 xendev_class->backend = "qdisk"; 534 xendev_class->device = "vbd"; 535 xendev_class->get_name = xen_block_get_name; 536 xendev_class->realize = xen_block_realize; 537 xendev_class->frontend_changed = xen_block_frontend_changed; 538 xendev_class->unrealize = xen_block_unrealize; 539 540 device_class_set_props(dev_class, xen_block_props); 541 } 542 543 static const TypeInfo xen_block_type_info = { 544 .name = TYPE_XEN_BLOCK_DEVICE, 545 .parent = TYPE_XEN_DEVICE, 546 .instance_size = sizeof(XenBlockDevice), 547 .abstract = true, 548 .class_size = sizeof(XenBlockDeviceClass), 549 .class_init = xen_block_class_init, 550 }; 551 552 static void xen_disk_unrealize(XenBlockDevice *blockdev) 553 { 554 trace_xen_disk_unrealize(); 555 } 556 557 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp) 558 { 559 BlockConf *conf = &blockdev->props.conf; 560 561 trace_xen_disk_realize(); 562 563 blockdev->device_type = "disk"; 564 565 if (!conf->blk) { 566 error_setg(errp, "drive property not set"); 567 return; 568 } 569 570 blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY; 571 } 572 573 static void xen_disk_class_init(ObjectClass *class, void *data) 574 { 575 DeviceClass *dev_class = DEVICE_CLASS(class); 576 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); 577 578 blockdev_class->realize = xen_disk_realize; 579 blockdev_class->unrealize = xen_disk_unrealize; 580 581 dev_class->desc = "Xen Disk Device"; 582 } 583 584 static const TypeInfo xen_disk_type_info = { 585 .name = TYPE_XEN_DISK_DEVICE, 586 .parent = TYPE_XEN_BLOCK_DEVICE, 587 .instance_size = sizeof(XenDiskDevice), 588 .class_init = xen_disk_class_init, 589 }; 590 591 static void xen_cdrom_unrealize(XenBlockDevice *blockdev) 592 { 593 trace_xen_cdrom_unrealize(); 594 } 595 596 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp) 597 { 598 BlockConf *conf = &blockdev->props.conf; 599 600 trace_xen_cdrom_realize(); 601 602 blockdev->device_type = "cdrom"; 603 604 if (!conf->blk) { 605 int rc; 606 607 /* Set up an empty drive */ 608 conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); 609 610 rc = blk_attach_dev(conf->blk, DEVICE(blockdev)); 611 if (!rc) { 612 error_setg_errno(errp, -rc, "failed to create drive"); 613 return; 614 } 615 } 616 617 blockdev->info = VDISK_READONLY | VDISK_CDROM; 618 } 619 620 static void xen_cdrom_class_init(ObjectClass *class, void *data) 621 { 622 DeviceClass *dev_class = DEVICE_CLASS(class); 623 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); 624 625 blockdev_class->realize = xen_cdrom_realize; 626 blockdev_class->unrealize = xen_cdrom_unrealize; 627 628 dev_class->desc = "Xen CD-ROM Device"; 629 } 630 631 static const TypeInfo xen_cdrom_type_info = { 632 .name = TYPE_XEN_CDROM_DEVICE, 633 .parent = TYPE_XEN_BLOCK_DEVICE, 634 .instance_size = sizeof(XenCDRomDevice), 635 .class_init = xen_cdrom_class_init, 636 }; 637 638 static void xen_block_register_types(void) 639 { 640 type_register_static(&xen_block_type_info); 641 type_register_static(&xen_disk_type_info); 642 type_register_static(&xen_cdrom_type_info); 643 } 644 645 type_init(xen_block_register_types) 646 647 static void xen_block_blockdev_del(const char *node_name, Error **errp) 648 { 649 trace_xen_block_blockdev_del(node_name); 650 651 qmp_blockdev_del(node_name, errp); 652 } 653 654 static char *xen_block_blockdev_add(const char *id, QDict *qdict, 655 Error **errp) 656 { 657 ERRP_GUARD(); 658 const char *driver = qdict_get_try_str(qdict, "driver"); 659 BlockdevOptions *options = NULL; 660 char *node_name; 661 Visitor *v; 662 663 if (!driver) { 664 error_setg(errp, "no 'driver' parameter"); 665 return NULL; 666 } 667 668 node_name = g_strdup_printf("%s-%s", id, driver); 669 qdict_put_str(qdict, "node-name", node_name); 670 671 trace_xen_block_blockdev_add(node_name); 672 673 v = qobject_input_visitor_new(QOBJECT(qdict)); 674 visit_type_BlockdevOptions(v, NULL, &options, errp); 675 visit_free(v); 676 if (!options) { 677 goto fail; 678 } 679 680 qmp_blockdev_add(options, errp); 681 682 if (*errp) { 683 goto fail; 684 } 685 686 qapi_free_BlockdevOptions(options); 687 688 return node_name; 689 690 fail: 691 if (options) { 692 qapi_free_BlockdevOptions(options); 693 } 694 g_free(node_name); 695 696 return NULL; 697 } 698 699 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp) 700 { 701 ERRP_GUARD(); 702 char *node_name = drive->node_name; 703 704 if (node_name) { 705 xen_block_blockdev_del(node_name, errp); 706 if (*errp) { 707 return; 708 } 709 g_free(node_name); 710 drive->node_name = NULL; 711 } 712 g_free(drive->id); 713 g_free(drive); 714 } 715 716 static XenBlockDrive *xen_block_drive_create(const char *id, 717 const char *device_type, 718 QDict *opts, Error **errp) 719 { 720 ERRP_GUARD(); 721 const char *params = qdict_get_try_str(opts, "params"); 722 const char *mode = qdict_get_try_str(opts, "mode"); 723 const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe"); 724 const char *discard_enable = qdict_get_try_str(opts, "discard-enable"); 725 char *driver = NULL; 726 char *filename = NULL; 727 XenBlockDrive *drive = NULL; 728 QDict *file_layer; 729 QDict *driver_layer; 730 struct stat st; 731 int rc; 732 733 if (params) { 734 char **v = g_strsplit(params, ":", 2); 735 736 if (v[1] == NULL) { 737 filename = g_strdup(v[0]); 738 driver = g_strdup("raw"); 739 } else { 740 if (strcmp(v[0], "aio") == 0) { 741 driver = g_strdup("raw"); 742 } else if (strcmp(v[0], "vhd") == 0) { 743 driver = g_strdup("vpc"); 744 } else { 745 driver = g_strdup(v[0]); 746 } 747 filename = g_strdup(v[1]); 748 } 749 750 g_strfreev(v); 751 } else { 752 error_setg(errp, "no params"); 753 goto done; 754 } 755 756 assert(filename); 757 assert(driver); 758 759 drive = g_new0(XenBlockDrive, 1); 760 drive->id = g_strdup(id); 761 762 file_layer = qdict_new(); 763 driver_layer = qdict_new(); 764 765 rc = stat(filename, &st); 766 if (rc) { 767 error_setg_errno(errp, errno, "Could not stat file '%s'", filename); 768 goto done; 769 } 770 if (S_ISBLK(st.st_mode)) { 771 qdict_put_str(file_layer, "driver", "host_device"); 772 } else { 773 qdict_put_str(file_layer, "driver", "file"); 774 } 775 776 qdict_put_str(file_layer, "filename", filename); 777 g_free(filename); 778 779 if (mode && *mode != 'w') { 780 qdict_put_bool(file_layer, "read-only", true); 781 } 782 783 if (direct_io_safe) { 784 unsigned long value; 785 786 if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) { 787 QDict *cache_qdict = qdict_new(); 788 789 qdict_put_bool(cache_qdict, "direct", true); 790 qdict_put(file_layer, "cache", cache_qdict); 791 792 qdict_put_str(file_layer, "aio", "native"); 793 } 794 } 795 796 if (discard_enable) { 797 unsigned long value; 798 799 if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) { 800 qdict_put_str(file_layer, "discard", "unmap"); 801 qdict_put_str(driver_layer, "discard", "unmap"); 802 } 803 } 804 805 /* 806 * It is necessary to turn file locking off as an emulated device 807 * may have already opened the same image file. 808 */ 809 qdict_put_str(file_layer, "locking", "off"); 810 811 qdict_put_str(driver_layer, "driver", driver); 812 g_free(driver); 813 814 qdict_put(driver_layer, "file", file_layer); 815 816 g_assert(!drive->node_name); 817 drive->node_name = xen_block_blockdev_add(drive->id, driver_layer, 818 errp); 819 820 qobject_unref(driver_layer); 821 822 done: 823 if (*errp) { 824 xen_block_drive_destroy(drive, NULL); 825 return NULL; 826 } 827 828 return drive; 829 } 830 831 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive) 832 { 833 return drive->node_name ? drive->node_name : ""; 834 } 835 836 static void xen_block_iothread_destroy(XenBlockIOThread *iothread, 837 Error **errp) 838 { 839 qmp_object_del(iothread->id, errp); 840 841 g_free(iothread->id); 842 g_free(iothread); 843 } 844 845 static XenBlockIOThread *xen_block_iothread_create(const char *id, 846 Error **errp) 847 { 848 ERRP_GUARD(); 849 XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1); 850 ObjectOptions *opts; 851 852 iothread->id = g_strdup(id); 853 854 opts = g_new(ObjectOptions, 1); 855 *opts = (ObjectOptions) { 856 .qom_type = OBJECT_TYPE_IOTHREAD, 857 .id = g_strdup(id), 858 }; 859 qmp_object_add(opts, errp); 860 qapi_free_ObjectOptions(opts); 861 862 if (*errp) { 863 g_free(iothread->id); 864 g_free(iothread); 865 return NULL; 866 } 867 868 return iothread; 869 } 870 871 static void xen_block_device_create(XenBackendInstance *backend, 872 QDict *opts, Error **errp) 873 { 874 ERRP_GUARD(); 875 XenBus *xenbus = xen_backend_get_bus(backend); 876 const char *name = xen_backend_get_name(backend); 877 unsigned long number; 878 const char *vdev, *device_type; 879 XenBlockDrive *drive = NULL; 880 XenBlockIOThread *iothread = NULL; 881 XenDevice *xendev = NULL; 882 const char *type; 883 XenBlockDevice *blockdev; 884 885 if (qemu_strtoul(name, NULL, 10, &number)) { 886 error_setg(errp, "failed to parse name '%s'", name); 887 goto fail; 888 } 889 890 trace_xen_block_device_create(number); 891 892 vdev = qdict_get_try_str(opts, "dev"); 893 if (!vdev) { 894 error_setg(errp, "no dev parameter"); 895 goto fail; 896 } 897 898 device_type = qdict_get_try_str(opts, "device-type"); 899 if (!device_type) { 900 error_setg(errp, "no device-type parameter"); 901 goto fail; 902 } 903 904 if (!strcmp(device_type, "disk")) { 905 type = TYPE_XEN_DISK_DEVICE; 906 } else if (!strcmp(device_type, "cdrom")) { 907 type = TYPE_XEN_CDROM_DEVICE; 908 } else { 909 error_setg(errp, "invalid device-type parameter '%s'", device_type); 910 goto fail; 911 } 912 913 drive = xen_block_drive_create(vdev, device_type, opts, errp); 914 if (!drive) { 915 error_prepend(errp, "failed to create drive: "); 916 goto fail; 917 } 918 919 iothread = xen_block_iothread_create(vdev, errp); 920 if (*errp) { 921 error_prepend(errp, "failed to create iothread: "); 922 goto fail; 923 } 924 925 xendev = XEN_DEVICE(qdev_new(type)); 926 blockdev = XEN_BLOCK_DEVICE(xendev); 927 928 if (!object_property_set_str(OBJECT(xendev), "vdev", vdev, 929 errp)) { 930 error_prepend(errp, "failed to set 'vdev': "); 931 goto fail; 932 } 933 934 if (!object_property_set_str(OBJECT(xendev), "drive", 935 xen_block_drive_get_node_name(drive), 936 errp)) { 937 error_prepend(errp, "failed to set 'drive': "); 938 goto fail; 939 } 940 941 if (!object_property_set_str(OBJECT(xendev), "iothread", iothread->id, 942 errp)) { 943 error_prepend(errp, "failed to set 'iothread': "); 944 goto fail; 945 } 946 947 blockdev->iothread = iothread; 948 blockdev->drive = drive; 949 950 if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { 951 error_prepend(errp, "realization of device %s failed: ", type); 952 goto fail; 953 } 954 955 xen_backend_set_device(backend, xendev); 956 return; 957 958 fail: 959 if (xendev) { 960 object_unparent(OBJECT(xendev)); 961 } 962 963 if (iothread) { 964 xen_block_iothread_destroy(iothread, NULL); 965 } 966 967 if (drive) { 968 xen_block_drive_destroy(drive, NULL); 969 } 970 } 971 972 static void xen_block_device_destroy(XenBackendInstance *backend, 973 Error **errp) 974 { 975 ERRP_GUARD(); 976 XenDevice *xendev = xen_backend_get_device(backend); 977 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 978 XenBlockVdev *vdev = &blockdev->props.vdev; 979 XenBlockDrive *drive = blockdev->drive; 980 XenBlockIOThread *iothread = blockdev->iothread; 981 982 trace_xen_block_device_destroy(vdev->number); 983 984 object_unparent(OBJECT(xendev)); 985 986 /* 987 * Drain all pending RCU callbacks as object_unparent() frees `xendev' 988 * in a RCU callback. 989 * And due to the property "drive" still existing in `xendev', we 990 * can't destroy the XenBlockDrive associated with `xendev' with 991 * xen_block_drive_destroy() below. 992 */ 993 drain_call_rcu(); 994 995 if (iothread) { 996 xen_block_iothread_destroy(iothread, errp); 997 if (*errp) { 998 error_prepend(errp, "failed to destroy iothread: "); 999 return; 1000 } 1001 } 1002 1003 if (drive) { 1004 xen_block_drive_destroy(drive, errp); 1005 if (*errp) { 1006 error_prepend(errp, "failed to destroy drive: "); 1007 return; 1008 } 1009 } 1010 } 1011 1012 static const XenBackendInfo xen_block_backend_info = { 1013 .type = "qdisk", 1014 .create = xen_block_device_create, 1015 .destroy = xen_block_device_destroy, 1016 }; 1017 1018 static void xen_block_register_backend(void) 1019 { 1020 xen_backend_register(&xen_block_backend_info); 1021 } 1022 1023 xen_backend_init(xen_block_register_backend);