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 const 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 const 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 static 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 const 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 }; 678 679 static void xen_block_class_init(ObjectClass *class, void *data) 680 { 681 DeviceClass *dev_class = DEVICE_CLASS(class); 682 XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); 683 684 xendev_class->backend = "qdisk"; 685 xendev_class->device = "vbd"; 686 xendev_class->get_name = xen_block_get_name; 687 xendev_class->realize = xen_block_realize; 688 xendev_class->frontend_changed = xen_block_frontend_changed; 689 xendev_class->unrealize = xen_block_unrealize; 690 691 device_class_set_props(dev_class, xen_block_props); 692 } 693 694 static const TypeInfo xen_block_type_info = { 695 .name = TYPE_XEN_BLOCK_DEVICE, 696 .parent = TYPE_XEN_DEVICE, 697 .instance_size = sizeof(XenBlockDevice), 698 .abstract = true, 699 .class_size = sizeof(XenBlockDeviceClass), 700 .class_init = xen_block_class_init, 701 }; 702 703 static void xen_disk_unrealize(XenBlockDevice *blockdev) 704 { 705 trace_xen_disk_unrealize(); 706 } 707 708 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp) 709 { 710 BlockConf *conf = &blockdev->props.conf; 711 712 trace_xen_disk_realize(); 713 714 blockdev->device_type = "disk"; 715 716 if (!conf->blk) { 717 error_setg(errp, "drive property not set"); 718 return; 719 } 720 721 blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY; 722 } 723 724 static void xen_disk_class_init(ObjectClass *class, void *data) 725 { 726 DeviceClass *dev_class = DEVICE_CLASS(class); 727 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); 728 729 blockdev_class->realize = xen_disk_realize; 730 blockdev_class->unrealize = xen_disk_unrealize; 731 732 dev_class->desc = "Xen Disk Device"; 733 } 734 735 static const TypeInfo xen_disk_type_info = { 736 .name = TYPE_XEN_DISK_DEVICE, 737 .parent = TYPE_XEN_BLOCK_DEVICE, 738 .instance_size = sizeof(XenDiskDevice), 739 .class_init = xen_disk_class_init, 740 }; 741 742 static void xen_cdrom_unrealize(XenBlockDevice *blockdev) 743 { 744 trace_xen_cdrom_unrealize(); 745 } 746 747 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp) 748 { 749 BlockConf *conf = &blockdev->props.conf; 750 751 trace_xen_cdrom_realize(); 752 753 blockdev->device_type = "cdrom"; 754 755 if (!conf->blk) { 756 int rc; 757 758 /* Set up an empty drive */ 759 conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); 760 761 rc = blk_attach_dev(conf->blk, DEVICE(blockdev)); 762 if (!rc) { 763 error_setg_errno(errp, -rc, "failed to create drive"); 764 return; 765 } 766 } 767 768 blockdev->info = VDISK_READONLY | VDISK_CDROM; 769 } 770 771 static void xen_cdrom_class_init(ObjectClass *class, void *data) 772 { 773 DeviceClass *dev_class = DEVICE_CLASS(class); 774 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); 775 776 blockdev_class->realize = xen_cdrom_realize; 777 blockdev_class->unrealize = xen_cdrom_unrealize; 778 779 dev_class->desc = "Xen CD-ROM Device"; 780 } 781 782 static const TypeInfo xen_cdrom_type_info = { 783 .name = TYPE_XEN_CDROM_DEVICE, 784 .parent = TYPE_XEN_BLOCK_DEVICE, 785 .instance_size = sizeof(XenCDRomDevice), 786 .class_init = xen_cdrom_class_init, 787 }; 788 789 static void xen_block_register_types(void) 790 { 791 type_register_static(&xen_block_type_info); 792 type_register_static(&xen_disk_type_info); 793 type_register_static(&xen_cdrom_type_info); 794 } 795 796 type_init(xen_block_register_types) 797 798 static void xen_block_blockdev_del(const char *node_name, Error **errp) 799 { 800 trace_xen_block_blockdev_del(node_name); 801 802 qmp_blockdev_del(node_name, errp); 803 } 804 805 static char *xen_block_blockdev_add(const char *id, QDict *qdict, 806 Error **errp) 807 { 808 ERRP_GUARD(); 809 const char *driver = qdict_get_try_str(qdict, "driver"); 810 BlockdevOptions *options = NULL; 811 char *node_name; 812 Visitor *v; 813 814 if (!driver) { 815 error_setg(errp, "no 'driver' parameter"); 816 return NULL; 817 } 818 819 node_name = g_strdup_printf("%s-%s", id, driver); 820 qdict_put_str(qdict, "node-name", node_name); 821 822 trace_xen_block_blockdev_add(node_name); 823 824 v = qobject_input_visitor_new(QOBJECT(qdict)); 825 visit_type_BlockdevOptions(v, NULL, &options, errp); 826 visit_free(v); 827 if (!options) { 828 goto fail; 829 } 830 831 qmp_blockdev_add(options, errp); 832 833 if (*errp) { 834 goto fail; 835 } 836 837 qapi_free_BlockdevOptions(options); 838 839 return node_name; 840 841 fail: 842 if (options) { 843 qapi_free_BlockdevOptions(options); 844 } 845 g_free(node_name); 846 847 return NULL; 848 } 849 850 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp) 851 { 852 ERRP_GUARD(); 853 char *node_name = drive->node_name; 854 855 if (node_name) { 856 xen_block_blockdev_del(node_name, errp); 857 if (*errp) { 858 return; 859 } 860 g_free(node_name); 861 drive->node_name = NULL; 862 } 863 g_free(drive->id); 864 g_free(drive); 865 } 866 867 static XenBlockDrive *xen_block_drive_create(const char *id, 868 const char *device_type, 869 QDict *opts, Error **errp) 870 { 871 ERRP_GUARD(); 872 const char *params = qdict_get_try_str(opts, "params"); 873 const char *mode = qdict_get_try_str(opts, "mode"); 874 const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe"); 875 const char *discard_enable = qdict_get_try_str(opts, "discard-enable"); 876 char *driver = NULL; 877 char *filename = NULL; 878 XenBlockDrive *drive = NULL; 879 QDict *file_layer; 880 QDict *driver_layer; 881 struct stat st; 882 int rc; 883 884 if (params) { 885 char **v = g_strsplit(params, ":", 2); 886 887 if (v[1] == NULL) { 888 filename = g_strdup(v[0]); 889 driver = g_strdup("raw"); 890 } else { 891 if (strcmp(v[0], "aio") == 0) { 892 driver = g_strdup("raw"); 893 } else if (strcmp(v[0], "vhd") == 0) { 894 driver = g_strdup("vpc"); 895 } else { 896 driver = g_strdup(v[0]); 897 } 898 filename = g_strdup(v[1]); 899 } 900 901 g_strfreev(v); 902 } else { 903 error_setg(errp, "no params"); 904 goto done; 905 } 906 907 assert(filename); 908 assert(driver); 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); 1176