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/block/xen_blkif.h" 23 #include "hw/qdev-properties.h" 24 #include "hw/xen/xen-block.h" 25 #include "hw/xen/xen-backend.h" 26 #include "sysemu/blockdev.h" 27 #include "sysemu/block-backend.h" 28 #include "sysemu/iothread.h" 29 #include "dataplane/xen-block.h" 30 #include "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 if (xen_device_frontend_scanf(xendev, "protocol", "%ms", &str) != 1) { 243 /* x86 defaults to the 32-bit protocol even for 64-bit guests. */ 244 if (object_dynamic_cast(OBJECT(qdev_get_machine()), "x86-machine")) { 245 protocol = BLKIF_PROTOCOL_X86_32; 246 } else { 247 protocol = BLKIF_PROTOCOL_NATIVE; 248 } 249 } else { 250 if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) { 251 protocol = BLKIF_PROTOCOL_X86_32; 252 } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) { 253 protocol = BLKIF_PROTOCOL_X86_64; 254 } else { 255 protocol = BLKIF_PROTOCOL_NATIVE; 256 } 257 258 free(str); 259 } 260 261 xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref, 262 event_channel, protocol, errp); 263 264 g_free(ring_ref); 265 } 266 267 static void xen_block_unrealize(XenDevice *xendev) 268 { 269 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 270 XenBlockDeviceClass *blockdev_class = 271 XEN_BLOCK_DEVICE_GET_CLASS(xendev); 272 const char *type = object_get_typename(OBJECT(blockdev)); 273 XenBlockVdev *vdev = &blockdev->props.vdev; 274 275 if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { 276 return; 277 } 278 279 trace_xen_block_unrealize(type, vdev->disk, vdev->partition); 280 281 /* Disconnect from the frontend in case this has not already happened */ 282 xen_block_disconnect(xendev, NULL); 283 284 xen_block_dataplane_destroy(blockdev->dataplane); 285 blockdev->dataplane = NULL; 286 287 if (blockdev_class->unrealize) { 288 blockdev_class->unrealize(blockdev); 289 } 290 } 291 292 static void xen_block_set_size(XenBlockDevice *blockdev) 293 { 294 const char *type = object_get_typename(OBJECT(blockdev)); 295 XenBlockVdev *vdev = &blockdev->props.vdev; 296 BlockConf *conf = &blockdev->props.conf; 297 int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size; 298 XenDevice *xendev = XEN_DEVICE(blockdev); 299 300 trace_xen_block_size(type, vdev->disk, vdev->partition, sectors); 301 302 xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors); 303 } 304 305 static void xen_block_resize_cb(void *opaque) 306 { 307 XenBlockDevice *blockdev = opaque; 308 XenDevice *xendev = XEN_DEVICE(blockdev); 309 enum xenbus_state state = xen_device_backend_get_state(xendev); 310 311 xen_block_set_size(blockdev); 312 313 /* 314 * Mimic the behaviour of Linux xen-blkback and re-write the state 315 * to trigger the frontend watch. 316 */ 317 xen_device_backend_printf(xendev, "state", "%u", state); 318 } 319 320 /* Suspend request handling */ 321 static void xen_block_drained_begin(void *opaque) 322 { 323 XenBlockDevice *blockdev = opaque; 324 325 xen_block_dataplane_detach(blockdev->dataplane); 326 } 327 328 /* Resume request handling */ 329 static void xen_block_drained_end(void *opaque) 330 { 331 XenBlockDevice *blockdev = opaque; 332 333 xen_block_dataplane_attach(blockdev->dataplane); 334 } 335 336 static const BlockDevOps xen_block_dev_ops = { 337 .resize_cb = xen_block_resize_cb, 338 .drained_begin = xen_block_drained_begin, 339 .drained_end = xen_block_drained_end, 340 }; 341 342 static void xen_block_realize(XenDevice *xendev, Error **errp) 343 { 344 ERRP_GUARD(); 345 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 346 XenBlockDeviceClass *blockdev_class = 347 XEN_BLOCK_DEVICE_GET_CLASS(xendev); 348 const char *type = object_get_typename(OBJECT(blockdev)); 349 XenBlockVdev *vdev = &blockdev->props.vdev; 350 BlockConf *conf = &blockdev->props.conf; 351 BlockBackend *blk = conf->blk; 352 353 if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { 354 error_setg(errp, "vdev property not set"); 355 return; 356 } 357 358 trace_xen_block_realize(type, vdev->disk, vdev->partition); 359 360 if (blockdev_class->realize) { 361 blockdev_class->realize(blockdev, errp); 362 if (*errp) { 363 return; 364 } 365 } 366 367 /* 368 * The blkif protocol does not deal with removable media, so it must 369 * always be present, even for CDRom devices. 370 */ 371 assert(blk); 372 if (!blk_is_inserted(blk)) { 373 error_setg(errp, "device needs media, but drive is empty"); 374 return; 375 } 376 377 if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY, 378 true, errp)) { 379 return; 380 } 381 382 if (!(blockdev->info & VDISK_CDROM) && 383 !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) { 384 return; 385 } 386 387 if (!blkconf_blocksizes(conf, errp)) { 388 return; 389 } 390 391 if (conf->discard_granularity == -1) { 392 conf->discard_granularity = conf->physical_block_size; 393 } 394 395 if (blk_get_flags(blk) & BDRV_O_UNMAP) { 396 xen_device_backend_printf(xendev, "feature-discard", "%u", 1); 397 xen_device_backend_printf(xendev, "discard-granularity", "%u", 398 conf->discard_granularity); 399 xen_device_backend_printf(xendev, "discard-alignment", "%u", 0); 400 } 401 402 xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1); 403 404 if (qemu_xen_gnttab_can_map_multi()) { 405 xen_device_backend_printf(xendev, "max-ring-page-order", "%u", 406 blockdev->props.max_ring_page_order); 407 } 408 409 xen_device_backend_printf(xendev, "info", "%u", blockdev->info); 410 411 xen_device_frontend_printf(xendev, "virtual-device", "%lu", 412 vdev->number); 413 xen_device_frontend_printf(xendev, "device-type", "%s", 414 blockdev->device_type); 415 416 xen_device_backend_printf(xendev, "sector-size", "%u", 417 conf->logical_block_size); 418 419 xen_block_set_size(blockdev); 420 421 blockdev->dataplane = 422 xen_block_dataplane_create(xendev, blk, conf->logical_block_size, 423 blockdev->props.iothread); 424 425 blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev); 426 } 427 428 static void xen_block_frontend_changed(XenDevice *xendev, 429 enum xenbus_state frontend_state, 430 Error **errp) 431 { 432 ERRP_GUARD(); 433 enum xenbus_state backend_state = xen_device_backend_get_state(xendev); 434 435 switch (frontend_state) { 436 case XenbusStateInitialised: 437 case XenbusStateConnected: 438 if (backend_state == XenbusStateConnected) { 439 break; 440 } 441 442 xen_block_disconnect(xendev, errp); 443 if (*errp) { 444 break; 445 } 446 447 xen_block_connect(xendev, errp); 448 if (*errp) { 449 break; 450 } 451 452 xen_device_backend_set_state(xendev, XenbusStateConnected); 453 break; 454 455 case XenbusStateClosing: 456 xen_device_backend_set_state(xendev, XenbusStateClosing); 457 break; 458 459 case XenbusStateClosed: 460 case XenbusStateUnknown: 461 xen_block_disconnect(xendev, errp); 462 if (*errp) { 463 break; 464 } 465 466 xen_device_backend_set_state(xendev, XenbusStateClosed); 467 break; 468 469 default: 470 break; 471 } 472 } 473 474 static char *disk_to_vbd_name(unsigned int disk) 475 { 476 char *name, *prefix = (disk >= 26) ? 477 disk_to_vbd_name((disk / 26) - 1) : g_strdup(""); 478 479 name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26); 480 g_free(prefix); 481 482 return name; 483 } 484 485 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name, 486 void *opaque, Error **errp) 487 { 488 Property *prop = opaque; 489 XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); 490 char *str; 491 492 switch (vdev->type) { 493 case XEN_BLOCK_VDEV_TYPE_DP: 494 str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition); 495 break; 496 497 case XEN_BLOCK_VDEV_TYPE_XVD: 498 case XEN_BLOCK_VDEV_TYPE_HD: 499 case XEN_BLOCK_VDEV_TYPE_SD: { 500 char *vbd_name = disk_to_vbd_name(vdev->disk); 501 502 str = g_strdup_printf("%s%s%lu", 503 (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ? 504 "xvd" : 505 (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ? 506 "hd" : 507 "sd", 508 vbd_name, vdev->partition); 509 g_free(vbd_name); 510 break; 511 } 512 default: 513 error_setg(errp, "invalid vdev type"); 514 return; 515 } 516 517 visit_type_str(v, name, &str, errp); 518 g_free(str); 519 } 520 521 static int vbd_name_to_disk(const char *name, const char **endp, 522 unsigned long *disk) 523 { 524 unsigned int n = 0; 525 526 while (*name != '\0') { 527 if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) { 528 break; 529 } 530 531 n *= 26; 532 n += *name++ - 'a' + 1; 533 } 534 *endp = name; 535 536 if (!n) { 537 return -1; 538 } 539 540 *disk = n - 1; 541 542 return 0; 543 } 544 545 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name, 546 void *opaque, Error **errp) 547 { 548 Property *prop = opaque; 549 XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); 550 char *str, *p; 551 const char *end; 552 553 if (!visit_type_str(v, name, &str, errp)) { 554 return; 555 } 556 557 p = strchr(str, 'd'); 558 if (!p) { 559 goto invalid; 560 } 561 562 *p++ = '\0'; 563 if (*str == '\0') { 564 vdev->type = XEN_BLOCK_VDEV_TYPE_DP; 565 } else if (strcmp(str, "xv") == 0) { 566 vdev->type = XEN_BLOCK_VDEV_TYPE_XVD; 567 } else if (strcmp(str, "h") == 0) { 568 vdev->type = XEN_BLOCK_VDEV_TYPE_HD; 569 } else if (strcmp(str, "s") == 0) { 570 vdev->type = XEN_BLOCK_VDEV_TYPE_SD; 571 } else { 572 goto invalid; 573 } 574 575 if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) { 576 if (qemu_strtoul(p, &end, 10, &vdev->disk)) { 577 goto invalid; 578 } 579 580 if (*end == 'p') { 581 if (*(++end) == '\0') { 582 goto invalid; 583 } 584 } 585 } else { 586 if (vbd_name_to_disk(p, &end, &vdev->disk)) { 587 goto invalid; 588 } 589 } 590 591 if (*end != '\0') { 592 p = (char *)end; 593 594 if (qemu_strtoul(p, &end, 10, &vdev->partition)) { 595 goto invalid; 596 } 597 598 if (*end != '\0') { 599 goto invalid; 600 } 601 } else { 602 vdev->partition = 0; 603 } 604 605 switch (vdev->type) { 606 case XEN_BLOCK_VDEV_TYPE_DP: 607 case XEN_BLOCK_VDEV_TYPE_XVD: 608 if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { 609 vdev->number = (XVDA_MAJOR << 8) | (vdev->disk << 4) | 610 vdev->partition; 611 } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) { 612 vdev->number = (XVDQ_MAJOR << 8) | (vdev->disk << 8) | 613 vdev->partition; 614 } else { 615 goto invalid; 616 } 617 break; 618 619 case XEN_BLOCK_VDEV_TYPE_HD: 620 if ((vdev->disk == 0 || vdev->disk == 1) && 621 vdev->partition < (1 << 6)) { 622 vdev->number = (HDA_MAJOR << 8) | (vdev->disk << 6) | 623 vdev->partition; 624 } else if ((vdev->disk == 2 || vdev->disk == 3) && 625 vdev->partition < (1 << 6)) { 626 vdev->number = (HDC_MAJOR << 8) | ((vdev->disk - 2) << 6) | 627 vdev->partition; 628 } else { 629 goto invalid; 630 } 631 break; 632 633 case XEN_BLOCK_VDEV_TYPE_SD: 634 if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { 635 vdev->number = (SDA_MAJOR << 8) | (vdev->disk << 4) | 636 vdev->partition; 637 } else { 638 goto invalid; 639 } 640 break; 641 642 default: 643 goto invalid; 644 } 645 646 g_free(str); 647 return; 648 649 invalid: 650 error_setg(errp, "invalid virtual disk specifier"); 651 652 vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID; 653 g_free(str); 654 } 655 656 /* 657 * This property deals with 'vdev' names adhering to the Xen VBD naming 658 * scheme described in: 659 * 660 * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html 661 */ 662 const PropertyInfo xen_block_prop_vdev = { 663 .name = "str", 664 .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*", 665 .get = xen_block_get_vdev, 666 .set = xen_block_set_vdev, 667 }; 668 669 static Property xen_block_props[] = { 670 DEFINE_PROP("vdev", XenBlockDevice, props.vdev, 671 xen_block_prop_vdev, XenBlockVdev), 672 DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf), 673 DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice, 674 props.max_ring_page_order, 4), 675 DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread, 676 TYPE_IOTHREAD, IOThread *), 677 DEFINE_PROP_END_OF_LIST() 678 }; 679 680 static void xen_block_class_init(ObjectClass *class, void *data) 681 { 682 DeviceClass *dev_class = DEVICE_CLASS(class); 683 XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); 684 685 xendev_class->backend = "qdisk"; 686 xendev_class->device = "vbd"; 687 xendev_class->get_name = xen_block_get_name; 688 xendev_class->realize = xen_block_realize; 689 xendev_class->frontend_changed = xen_block_frontend_changed; 690 xendev_class->unrealize = xen_block_unrealize; 691 692 device_class_set_props(dev_class, xen_block_props); 693 } 694 695 static const TypeInfo xen_block_type_info = { 696 .name = TYPE_XEN_BLOCK_DEVICE, 697 .parent = TYPE_XEN_DEVICE, 698 .instance_size = sizeof(XenBlockDevice), 699 .abstract = true, 700 .class_size = sizeof(XenBlockDeviceClass), 701 .class_init = xen_block_class_init, 702 }; 703 704 static void xen_disk_unrealize(XenBlockDevice *blockdev) 705 { 706 trace_xen_disk_unrealize(); 707 } 708 709 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp) 710 { 711 BlockConf *conf = &blockdev->props.conf; 712 713 trace_xen_disk_realize(); 714 715 blockdev->device_type = "disk"; 716 717 if (!conf->blk) { 718 error_setg(errp, "drive property not set"); 719 return; 720 } 721 722 blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY; 723 } 724 725 static void xen_disk_class_init(ObjectClass *class, void *data) 726 { 727 DeviceClass *dev_class = DEVICE_CLASS(class); 728 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); 729 730 blockdev_class->realize = xen_disk_realize; 731 blockdev_class->unrealize = xen_disk_unrealize; 732 733 dev_class->desc = "Xen Disk Device"; 734 } 735 736 static const TypeInfo xen_disk_type_info = { 737 .name = TYPE_XEN_DISK_DEVICE, 738 .parent = TYPE_XEN_BLOCK_DEVICE, 739 .instance_size = sizeof(XenDiskDevice), 740 .class_init = xen_disk_class_init, 741 }; 742 743 static void xen_cdrom_unrealize(XenBlockDevice *blockdev) 744 { 745 trace_xen_cdrom_unrealize(); 746 } 747 748 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp) 749 { 750 BlockConf *conf = &blockdev->props.conf; 751 752 trace_xen_cdrom_realize(); 753 754 blockdev->device_type = "cdrom"; 755 756 if (!conf->blk) { 757 int rc; 758 759 /* Set up an empty drive */ 760 conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); 761 762 rc = blk_attach_dev(conf->blk, DEVICE(blockdev)); 763 if (!rc) { 764 error_setg_errno(errp, -rc, "failed to create drive"); 765 return; 766 } 767 } 768 769 blockdev->info = VDISK_READONLY | VDISK_CDROM; 770 } 771 772 static void xen_cdrom_class_init(ObjectClass *class, void *data) 773 { 774 DeviceClass *dev_class = DEVICE_CLASS(class); 775 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); 776 777 blockdev_class->realize = xen_cdrom_realize; 778 blockdev_class->unrealize = xen_cdrom_unrealize; 779 780 dev_class->desc = "Xen CD-ROM Device"; 781 } 782 783 static const TypeInfo xen_cdrom_type_info = { 784 .name = TYPE_XEN_CDROM_DEVICE, 785 .parent = TYPE_XEN_BLOCK_DEVICE, 786 .instance_size = sizeof(XenCDRomDevice), 787 .class_init = xen_cdrom_class_init, 788 }; 789 790 static void xen_block_register_types(void) 791 { 792 type_register_static(&xen_block_type_info); 793 type_register_static(&xen_disk_type_info); 794 type_register_static(&xen_cdrom_type_info); 795 } 796 797 type_init(xen_block_register_types) 798 799 static void xen_block_blockdev_del(const char *node_name, Error **errp) 800 { 801 trace_xen_block_blockdev_del(node_name); 802 803 qmp_blockdev_del(node_name, errp); 804 } 805 806 static char *xen_block_blockdev_add(const char *id, QDict *qdict, 807 Error **errp) 808 { 809 ERRP_GUARD(); 810 const char *driver = qdict_get_try_str(qdict, "driver"); 811 BlockdevOptions *options = NULL; 812 char *node_name; 813 Visitor *v; 814 815 if (!driver) { 816 error_setg(errp, "no 'driver' parameter"); 817 return NULL; 818 } 819 820 node_name = g_strdup_printf("%s-%s", id, driver); 821 qdict_put_str(qdict, "node-name", node_name); 822 823 trace_xen_block_blockdev_add(node_name); 824 825 v = qobject_input_visitor_new(QOBJECT(qdict)); 826 visit_type_BlockdevOptions(v, NULL, &options, errp); 827 visit_free(v); 828 if (!options) { 829 goto fail; 830 } 831 832 qmp_blockdev_add(options, errp); 833 834 if (*errp) { 835 goto fail; 836 } 837 838 qapi_free_BlockdevOptions(options); 839 840 return node_name; 841 842 fail: 843 if (options) { 844 qapi_free_BlockdevOptions(options); 845 } 846 g_free(node_name); 847 848 return NULL; 849 } 850 851 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp) 852 { 853 ERRP_GUARD(); 854 char *node_name = drive->node_name; 855 856 if (node_name) { 857 xen_block_blockdev_del(node_name, errp); 858 if (*errp) { 859 return; 860 } 861 g_free(node_name); 862 drive->node_name = NULL; 863 } 864 g_free(drive->id); 865 g_free(drive); 866 } 867 868 static XenBlockDrive *xen_block_drive_create(const char *id, 869 const char *device_type, 870 QDict *opts, Error **errp) 871 { 872 ERRP_GUARD(); 873 const char *params = qdict_get_try_str(opts, "params"); 874 const char *mode = qdict_get_try_str(opts, "mode"); 875 const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe"); 876 const char *discard_enable = qdict_get_try_str(opts, "discard-enable"); 877 char *driver = NULL; 878 char *filename = NULL; 879 XenBlockDrive *drive = NULL; 880 QDict *file_layer; 881 QDict *driver_layer; 882 struct stat st; 883 int rc; 884 885 if (params) { 886 char **v = g_strsplit(params, ":", 2); 887 888 if (v[1] == NULL) { 889 filename = g_strdup(v[0]); 890 driver = g_strdup("raw"); 891 } else { 892 if (strcmp(v[0], "aio") == 0) { 893 driver = g_strdup("raw"); 894 } else if (strcmp(v[0], "vhd") == 0) { 895 driver = g_strdup("vpc"); 896 } else { 897 driver = g_strdup(v[0]); 898 } 899 filename = g_strdup(v[1]); 900 } 901 902 g_strfreev(v); 903 } else { 904 error_setg(errp, "no params"); 905 goto done; 906 } 907 908 assert(filename); 909 assert(driver); 910 911 drive = g_new0(XenBlockDrive, 1); 912 drive->id = g_strdup(id); 913 914 rc = stat(filename, &st); 915 if (rc) { 916 error_setg_errno(errp, errno, "Could not stat file '%s'", filename); 917 goto done; 918 } 919 920 file_layer = qdict_new(); 921 driver_layer = qdict_new(); 922 923 if (S_ISBLK(st.st_mode)) { 924 qdict_put_str(file_layer, "driver", "host_device"); 925 } else { 926 qdict_put_str(file_layer, "driver", "file"); 927 } 928 929 qdict_put_str(file_layer, "filename", filename); 930 931 if (mode && *mode != 'w') { 932 qdict_put_bool(file_layer, "read-only", true); 933 } 934 935 if (direct_io_safe) { 936 unsigned long value; 937 938 if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) { 939 QDict *cache_qdict = qdict_new(); 940 941 qdict_put_bool(cache_qdict, "direct", true); 942 qdict_put(file_layer, "cache", cache_qdict); 943 944 qdict_put_str(file_layer, "aio", "native"); 945 } 946 } 947 948 if (discard_enable) { 949 unsigned long value; 950 951 if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) { 952 qdict_put_str(file_layer, "discard", "unmap"); 953 qdict_put_str(driver_layer, "discard", "unmap"); 954 } 955 } 956 957 /* 958 * It is necessary to turn file locking off as an emulated device 959 * may have already opened the same image file. 960 */ 961 qdict_put_str(file_layer, "locking", "off"); 962 963 qdict_put_str(driver_layer, "driver", driver); 964 965 qdict_put(driver_layer, "file", file_layer); 966 967 g_assert(!drive->node_name); 968 drive->node_name = xen_block_blockdev_add(drive->id, driver_layer, 969 errp); 970 971 qobject_unref(driver_layer); 972 973 done: 974 g_free(filename); 975 g_free(driver); 976 if (*errp) { 977 xen_block_drive_destroy(drive, NULL); 978 return NULL; 979 } 980 981 return drive; 982 } 983 984 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive) 985 { 986 return drive->node_name ? drive->node_name : ""; 987 } 988 989 static void xen_block_iothread_destroy(XenBlockIOThread *iothread, 990 Error **errp) 991 { 992 qmp_object_del(iothread->id, errp); 993 994 g_free(iothread->id); 995 g_free(iothread); 996 } 997 998 static XenBlockIOThread *xen_block_iothread_create(const char *id, 999 Error **errp) 1000 { 1001 ERRP_GUARD(); 1002 XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1); 1003 ObjectOptions *opts; 1004 1005 iothread->id = g_strdup(id); 1006 1007 opts = g_new(ObjectOptions, 1); 1008 *opts = (ObjectOptions) { 1009 .qom_type = OBJECT_TYPE_IOTHREAD, 1010 .id = g_strdup(id), 1011 }; 1012 qmp_object_add(opts, errp); 1013 qapi_free_ObjectOptions(opts); 1014 1015 if (*errp) { 1016 g_free(iothread->id); 1017 g_free(iothread); 1018 return NULL; 1019 } 1020 1021 return iothread; 1022 } 1023 1024 static void xen_block_device_create(XenBackendInstance *backend, 1025 QDict *opts, Error **errp) 1026 { 1027 ERRP_GUARD(); 1028 XenBus *xenbus = xen_backend_get_bus(backend); 1029 const char *name = xen_backend_get_name(backend); 1030 unsigned long number; 1031 const char *vdev, *device_type; 1032 XenBlockDrive *drive = NULL; 1033 XenBlockIOThread *iothread = NULL; 1034 XenDevice *xendev = NULL; 1035 const char *type; 1036 XenBlockDevice *blockdev; 1037 1038 if (qemu_strtoul(name, NULL, 10, &number)) { 1039 error_setg(errp, "failed to parse name '%s'", name); 1040 goto fail; 1041 } 1042 1043 trace_xen_block_device_create(number); 1044 1045 vdev = qdict_get_try_str(opts, "dev"); 1046 if (!vdev) { 1047 error_setg(errp, "no dev parameter"); 1048 goto fail; 1049 } 1050 1051 device_type = qdict_get_try_str(opts, "device-type"); 1052 if (!device_type) { 1053 error_setg(errp, "no device-type parameter"); 1054 goto fail; 1055 } 1056 1057 if (!strcmp(device_type, "disk")) { 1058 type = TYPE_XEN_DISK_DEVICE; 1059 } else if (!strcmp(device_type, "cdrom")) { 1060 type = TYPE_XEN_CDROM_DEVICE; 1061 } else { 1062 error_setg(errp, "invalid device-type parameter '%s'", device_type); 1063 goto fail; 1064 } 1065 1066 drive = xen_block_drive_create(vdev, device_type, opts, errp); 1067 if (!drive) { 1068 error_prepend(errp, "failed to create drive: "); 1069 goto fail; 1070 } 1071 1072 iothread = xen_block_iothread_create(vdev, errp); 1073 if (*errp) { 1074 error_prepend(errp, "failed to create iothread: "); 1075 goto fail; 1076 } 1077 1078 xendev = XEN_DEVICE(qdev_new(type)); 1079 blockdev = XEN_BLOCK_DEVICE(xendev); 1080 1081 if (!object_property_set_str(OBJECT(xendev), "vdev", vdev, 1082 errp)) { 1083 error_prepend(errp, "failed to set 'vdev': "); 1084 goto fail; 1085 } 1086 1087 if (!object_property_set_str(OBJECT(xendev), "drive", 1088 xen_block_drive_get_node_name(drive), 1089 errp)) { 1090 error_prepend(errp, "failed to set 'drive': "); 1091 goto fail; 1092 } 1093 1094 if (!object_property_set_str(OBJECT(xendev), "iothread", iothread->id, 1095 errp)) { 1096 error_prepend(errp, "failed to set 'iothread': "); 1097 goto fail; 1098 } 1099 1100 blockdev->iothread = iothread; 1101 blockdev->drive = drive; 1102 1103 if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { 1104 error_prepend(errp, "realization of device %s failed: ", type); 1105 goto fail; 1106 } 1107 1108 xen_backend_set_device(backend, xendev); 1109 return; 1110 1111 fail: 1112 if (xendev) { 1113 object_unparent(OBJECT(xendev)); 1114 } 1115 1116 if (iothread) { 1117 xen_block_iothread_destroy(iothread, NULL); 1118 } 1119 1120 if (drive) { 1121 xen_block_drive_destroy(drive, NULL); 1122 } 1123 } 1124 1125 static void xen_block_device_destroy(XenBackendInstance *backend, 1126 Error **errp) 1127 { 1128 ERRP_GUARD(); 1129 XenDevice *xendev = xen_backend_get_device(backend); 1130 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); 1131 XenBlockVdev *vdev = &blockdev->props.vdev; 1132 XenBlockDrive *drive = blockdev->drive; 1133 XenBlockIOThread *iothread = blockdev->iothread; 1134 1135 trace_xen_block_device_destroy(vdev->number); 1136 1137 object_unparent(OBJECT(xendev)); 1138 1139 /* 1140 * Drain all pending RCU callbacks as object_unparent() frees `xendev' 1141 * in a RCU callback. 1142 * And due to the property "drive" still existing in `xendev', we 1143 * can't destroy the XenBlockDrive associated with `xendev' with 1144 * xen_block_drive_destroy() below. 1145 */ 1146 drain_call_rcu(); 1147 1148 if (iothread) { 1149 xen_block_iothread_destroy(iothread, errp); 1150 if (*errp) { 1151 error_prepend(errp, "failed to destroy iothread: "); 1152 return; 1153 } 1154 } 1155 1156 if (drive) { 1157 xen_block_drive_destroy(drive, errp); 1158 if (*errp) { 1159 error_prepend(errp, "failed to destroy drive: "); 1160 return; 1161 } 1162 } 1163 } 1164 1165 static const XenBackendInfo xen_block_backend_info = { 1166 .type = "qdisk", 1167 .create = xen_block_device_create, 1168 .destroy = xen_block_device_destroy, 1169 }; 1170 1171 static void xen_block_register_backend(void) 1172 { 1173 xen_backend_register(&xen_block_backend_info); 1174 } 1175 1176 xen_backend_init(xen_block_register_backend); 1177