1 /*- 2 * Copyright (c) 2011, Bryan Venteicher <bryanv@daemoninthecloset.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 /* Driver for VirtIO block devices. */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/bio.h> 36 #include <sys/malloc.h> 37 #include <sys/module.h> 38 #include <sys/sglist.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/queue.h> 42 #include <sys/taskqueue.h> 43 44 #include <geom/geom_disk.h> 45 46 #include <machine/bus.h> 47 #include <machine/resource.h> 48 #include <sys/bus.h> 49 #include <sys/rman.h> 50 51 #include <dev/virtio/virtio.h> 52 #include <dev/virtio/virtqueue.h> 53 #include <dev/virtio/block/virtio_blk.h> 54 55 #include "virtio_if.h" 56 57 struct vtblk_request { 58 struct virtio_blk_outhdr vbr_hdr; 59 struct bio *vbr_bp; 60 uint8_t vbr_ack; 61 62 TAILQ_ENTRY(vtblk_request) vbr_link; 63 }; 64 65 struct vtblk_softc { 66 device_t vtblk_dev; 67 struct mtx vtblk_mtx; 68 uint64_t vtblk_features; 69 uint32_t vtblk_flags; 70 #define VTBLK_FLAG_INDIRECT 0x0001 71 #define VTBLK_FLAG_READONLY 0x0002 72 #define VTBLK_FLAG_DETACH 0x0004 73 #define VTBLK_FLAG_SUSPEND 0x0008 74 #define VTBLK_FLAG_DUMPING 0x0010 75 76 struct virtqueue *vtblk_vq; 77 struct sglist *vtblk_sglist; 78 struct disk *vtblk_disk; 79 80 struct bio_queue_head vtblk_bioq; 81 TAILQ_HEAD(, vtblk_request) 82 vtblk_req_free; 83 TAILQ_HEAD(, vtblk_request) 84 vtblk_req_ready; 85 86 struct taskqueue *vtblk_tq; 87 struct task vtblk_intr_task; 88 89 int vtblk_max_nsegs; 90 int vtblk_request_count; 91 92 struct vtblk_request vtblk_dump_request; 93 }; 94 95 static struct virtio_feature_desc vtblk_feature_desc[] = { 96 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 97 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 98 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 99 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 100 { VIRTIO_BLK_F_RO, "ReadOnly" }, 101 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 102 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 103 { VIRTIO_BLK_F_FLUSH, "FlushCmd" }, 104 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 105 106 { 0, NULL } 107 }; 108 109 static int vtblk_modevent(module_t, int, void *); 110 111 static int vtblk_probe(device_t); 112 static int vtblk_attach(device_t); 113 static int vtblk_detach(device_t); 114 static int vtblk_suspend(device_t); 115 static int vtblk_resume(device_t); 116 static int vtblk_shutdown(device_t); 117 118 static int vtblk_open(struct disk *); 119 static int vtblk_close(struct disk *); 120 static int vtblk_ioctl(struct disk *, u_long, void *, int, 121 struct thread *); 122 static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); 123 static void vtblk_strategy(struct bio *); 124 125 static void vtblk_negotiate_features(struct vtblk_softc *); 126 static int vtblk_maximum_segments(struct vtblk_softc *, 127 struct virtio_blk_config *); 128 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 129 static void vtblk_alloc_disk(struct vtblk_softc *, 130 struct virtio_blk_config *); 131 static void vtblk_create_disk(struct vtblk_softc *); 132 133 static int vtblk_quiesce(struct vtblk_softc *); 134 static void vtblk_startio(struct vtblk_softc *); 135 static struct vtblk_request * vtblk_bio_request(struct vtblk_softc *); 136 static int vtblk_execute_request(struct vtblk_softc *, 137 struct vtblk_request *); 138 139 static int vtblk_vq_intr(void *); 140 static void vtblk_intr_task(void *, int); 141 142 static void vtblk_stop(struct vtblk_softc *); 143 144 static void vtblk_get_ident(struct vtblk_softc *); 145 static void vtblk_prepare_dump(struct vtblk_softc *); 146 static int vtblk_write_dump(struct vtblk_softc *, void *, off_t, size_t); 147 static int vtblk_flush_dump(struct vtblk_softc *); 148 static int vtblk_poll_request(struct vtblk_softc *, 149 struct vtblk_request *); 150 151 static void vtblk_finish_completed(struct vtblk_softc *); 152 static void vtblk_drain_vq(struct vtblk_softc *, int); 153 static void vtblk_drain(struct vtblk_softc *); 154 155 static int vtblk_alloc_requests(struct vtblk_softc *); 156 static void vtblk_free_requests(struct vtblk_softc *); 157 static struct vtblk_request * vtblk_dequeue_request(struct vtblk_softc *); 158 static void vtblk_enqueue_request(struct vtblk_softc *, 159 struct vtblk_request *); 160 161 static struct vtblk_request * vtblk_dequeue_ready(struct vtblk_softc *); 162 static void vtblk_enqueue_ready(struct vtblk_softc *, 163 struct vtblk_request *); 164 165 static int vtblk_request_error(struct vtblk_request *); 166 static void vtblk_finish_bio(struct bio *, int); 167 168 /* Tunables. */ 169 static int vtblk_no_ident = 0; 170 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 171 172 /* Features desired/implemented by this driver. */ 173 #define VTBLK_FEATURES \ 174 (VIRTIO_BLK_F_BARRIER | \ 175 VIRTIO_BLK_F_SIZE_MAX | \ 176 VIRTIO_BLK_F_SEG_MAX | \ 177 VIRTIO_BLK_F_GEOMETRY | \ 178 VIRTIO_BLK_F_RO | \ 179 VIRTIO_BLK_F_BLK_SIZE | \ 180 VIRTIO_BLK_F_FLUSH | \ 181 VIRTIO_RING_F_INDIRECT_DESC) 182 183 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 184 #define VTBLK_LOCK_INIT(_sc, _name) \ 185 mtx_init(VTBLK_MTX((_sc)), (_name), \ 186 "VTBLK Lock", MTX_DEF) 187 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 188 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 189 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 190 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 191 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 192 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 193 194 #define VTBLK_DISK_NAME "vtbd" 195 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 196 197 /* 198 * Each block request uses at least two segments - one for the header 199 * and one for the status. 200 */ 201 #define VTBLK_MIN_SEGMENTS 2 202 203 static device_method_t vtblk_methods[] = { 204 /* Device methods. */ 205 DEVMETHOD(device_probe, vtblk_probe), 206 DEVMETHOD(device_attach, vtblk_attach), 207 DEVMETHOD(device_detach, vtblk_detach), 208 DEVMETHOD(device_suspend, vtblk_suspend), 209 DEVMETHOD(device_resume, vtblk_resume), 210 DEVMETHOD(device_shutdown, vtblk_shutdown), 211 212 DEVMETHOD_END 213 }; 214 215 static driver_t vtblk_driver = { 216 "vtblk", 217 vtblk_methods, 218 sizeof(struct vtblk_softc) 219 }; 220 static devclass_t vtblk_devclass; 221 222 DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, 223 vtblk_modevent, 0); 224 MODULE_VERSION(virtio_blk, 1); 225 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 226 227 static int 228 vtblk_modevent(module_t mod, int type, void *unused) 229 { 230 int error; 231 232 error = 0; 233 234 switch (type) { 235 case MOD_LOAD: 236 case MOD_QUIESCE: 237 case MOD_UNLOAD: 238 case MOD_SHUTDOWN: 239 break; 240 default: 241 error = EOPNOTSUPP; 242 break; 243 } 244 245 return (error); 246 } 247 248 static int 249 vtblk_probe(device_t dev) 250 { 251 252 if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) 253 return (ENXIO); 254 255 device_set_desc(dev, "VirtIO Block Adapter"); 256 257 return (BUS_PROBE_DEFAULT); 258 } 259 260 static int 261 vtblk_attach(device_t dev) 262 { 263 struct vtblk_softc *sc; 264 struct virtio_blk_config blkcfg; 265 int error; 266 267 sc = device_get_softc(dev); 268 sc->vtblk_dev = dev; 269 270 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 271 272 bioq_init(&sc->vtblk_bioq); 273 TAILQ_INIT(&sc->vtblk_req_free); 274 TAILQ_INIT(&sc->vtblk_req_ready); 275 276 virtio_set_feature_desc(dev, vtblk_feature_desc); 277 vtblk_negotiate_features(sc); 278 279 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 280 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 281 282 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 283 sc->vtblk_flags |= VTBLK_FLAG_READONLY; 284 285 /* Get local copy of config. */ 286 virtio_read_device_config(dev, 0, &blkcfg, 287 sizeof(struct virtio_blk_config)); 288 289 /* 290 * With the current sglist(9) implementation, it is not easy 291 * for us to support a maximum segment size as adjacent 292 * segments are coalesced. For now, just make sure it's larger 293 * than the maximum supported transfer size. 294 */ 295 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 296 if (blkcfg.size_max < MAXPHYS) { 297 error = ENOTSUP; 298 device_printf(dev, "host requires unsupported " 299 "maximum segment size feature\n"); 300 goto fail; 301 } 302 } 303 304 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 305 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 306 error = EINVAL; 307 device_printf(dev, "fewer than minimum number of segments " 308 "allowed: %d\n", sc->vtblk_max_nsegs); 309 goto fail; 310 } 311 312 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 313 if (sc->vtblk_sglist == NULL) { 314 error = ENOMEM; 315 device_printf(dev, "cannot allocate sglist\n"); 316 goto fail; 317 } 318 319 error = vtblk_alloc_virtqueue(sc); 320 if (error) { 321 device_printf(dev, "cannot allocate virtqueue\n"); 322 goto fail; 323 } 324 325 error = vtblk_alloc_requests(sc); 326 if (error) { 327 device_printf(dev, "cannot preallocate requests\n"); 328 goto fail; 329 } 330 331 vtblk_alloc_disk(sc, &blkcfg); 332 333 TASK_INIT(&sc->vtblk_intr_task, 0, vtblk_intr_task, sc); 334 sc->vtblk_tq = taskqueue_create_fast("vtblk_taskq", M_NOWAIT, 335 taskqueue_thread_enqueue, &sc->vtblk_tq); 336 if (sc->vtblk_tq == NULL) { 337 error = ENOMEM; 338 device_printf(dev, "cannot allocate taskqueue\n"); 339 goto fail; 340 } 341 taskqueue_start_threads(&sc->vtblk_tq, 1, PI_DISK, "%s taskq", 342 device_get_nameunit(dev)); 343 344 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 345 if (error) { 346 device_printf(dev, "cannot setup virtqueue interrupt\n"); 347 goto fail; 348 } 349 350 vtblk_create_disk(sc); 351 352 virtqueue_enable_intr(sc->vtblk_vq); 353 354 fail: 355 if (error) 356 vtblk_detach(dev); 357 358 return (error); 359 } 360 361 static int 362 vtblk_detach(device_t dev) 363 { 364 struct vtblk_softc *sc; 365 366 sc = device_get_softc(dev); 367 368 VTBLK_LOCK(sc); 369 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 370 if (device_is_attached(dev)) 371 vtblk_stop(sc); 372 VTBLK_UNLOCK(sc); 373 374 if (sc->vtblk_tq != NULL) { 375 taskqueue_drain(sc->vtblk_tq, &sc->vtblk_intr_task); 376 taskqueue_free(sc->vtblk_tq); 377 sc->vtblk_tq = NULL; 378 } 379 380 vtblk_drain(sc); 381 382 if (sc->vtblk_disk != NULL) { 383 disk_destroy(sc->vtblk_disk); 384 sc->vtblk_disk = NULL; 385 } 386 387 if (sc->vtblk_sglist != NULL) { 388 sglist_free(sc->vtblk_sglist); 389 sc->vtblk_sglist = NULL; 390 } 391 392 VTBLK_LOCK_DESTROY(sc); 393 394 return (0); 395 } 396 397 static int 398 vtblk_suspend(device_t dev) 399 { 400 struct vtblk_softc *sc; 401 int error; 402 403 sc = device_get_softc(dev); 404 405 VTBLK_LOCK(sc); 406 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 407 /* XXX BMV: virtio_stop(), etc needed here? */ 408 error = vtblk_quiesce(sc); 409 if (error) 410 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 411 VTBLK_UNLOCK(sc); 412 413 return (error); 414 } 415 416 static int 417 vtblk_resume(device_t dev) 418 { 419 struct vtblk_softc *sc; 420 421 sc = device_get_softc(dev); 422 423 VTBLK_LOCK(sc); 424 /* XXX BMV: virtio_reinit(), etc needed here? */ 425 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 426 vtblk_startio(sc); 427 VTBLK_UNLOCK(sc); 428 429 return (0); 430 } 431 432 static int 433 vtblk_shutdown(device_t dev) 434 { 435 436 return (0); 437 } 438 439 static int 440 vtblk_open(struct disk *dp) 441 { 442 struct vtblk_softc *sc; 443 444 if ((sc = dp->d_drv1) == NULL) 445 return (ENXIO); 446 447 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 448 } 449 450 static int 451 vtblk_close(struct disk *dp) 452 { 453 struct vtblk_softc *sc; 454 455 if ((sc = dp->d_drv1) == NULL) 456 return (ENXIO); 457 458 return (0); 459 } 460 461 static int 462 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 463 struct thread *td) 464 { 465 struct vtblk_softc *sc; 466 467 if ((sc = dp->d_drv1) == NULL) 468 return (ENXIO); 469 470 return (ENOTTY); 471 } 472 473 static int 474 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 475 size_t length) 476 { 477 struct disk *dp; 478 struct vtblk_softc *sc; 479 int error; 480 481 dp = arg; 482 483 if ((sc = dp->d_drv1) == NULL) 484 return (ENXIO); 485 486 VTBLK_LOCK(sc); 487 488 if ((sc->vtblk_flags & VTBLK_FLAG_DUMPING) == 0) { 489 vtblk_prepare_dump(sc); 490 sc->vtblk_flags |= VTBLK_FLAG_DUMPING; 491 } 492 493 if (length > 0) 494 error = vtblk_write_dump(sc, virtual, offset, length); 495 else if (virtual == NULL && offset == 0) 496 error = vtblk_flush_dump(sc); 497 else { 498 error = EINVAL; 499 sc->vtblk_flags &= ~VTBLK_FLAG_DUMPING; 500 } 501 502 VTBLK_UNLOCK(sc); 503 504 return (error); 505 } 506 507 static void 508 vtblk_strategy(struct bio *bp) 509 { 510 struct vtblk_softc *sc; 511 512 if ((sc = bp->bio_disk->d_drv1) == NULL) { 513 vtblk_finish_bio(bp, EINVAL); 514 return; 515 } 516 517 /* 518 * Fail any write if RO. Unfortunately, there does not seem to 519 * be a better way to report our readonly'ness to GEOM above. 520 */ 521 if (sc->vtblk_flags & VTBLK_FLAG_READONLY && 522 (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_FLUSH)) { 523 vtblk_finish_bio(bp, EROFS); 524 return; 525 } 526 527 #ifdef INVARIANTS 528 /* 529 * Prevent read/write buffers spanning too many segments from 530 * getting into the queue. This should only trip if d_maxsize 531 * was incorrectly set. 532 */ 533 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 534 int nsegs, max_nsegs; 535 536 nsegs = sglist_count(bp->bio_data, bp->bio_bcount); 537 max_nsegs = sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS; 538 539 KASSERT(nsegs <= max_nsegs, 540 ("bio %p spanned too many segments: %d, max: %d", 541 bp, nsegs, max_nsegs)); 542 } 543 #endif 544 545 VTBLK_LOCK(sc); 546 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 547 vtblk_finish_bio(bp, ENXIO); 548 else { 549 bioq_disksort(&sc->vtblk_bioq, bp); 550 551 if ((sc->vtblk_flags & VTBLK_FLAG_SUSPEND) == 0) 552 vtblk_startio(sc); 553 } 554 VTBLK_UNLOCK(sc); 555 } 556 557 static void 558 vtblk_negotiate_features(struct vtblk_softc *sc) 559 { 560 device_t dev; 561 uint64_t features; 562 563 dev = sc->vtblk_dev; 564 features = VTBLK_FEATURES; 565 566 sc->vtblk_features = virtio_negotiate_features(dev, features); 567 } 568 569 static int 570 vtblk_maximum_segments(struct vtblk_softc *sc, 571 struct virtio_blk_config *blkcfg) 572 { 573 device_t dev; 574 int nsegs; 575 576 dev = sc->vtblk_dev; 577 nsegs = VTBLK_MIN_SEGMENTS; 578 579 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 580 nsegs += MIN(blkcfg->seg_max, MAXPHYS / PAGE_SIZE + 1); 581 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 582 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 583 } else 584 nsegs += 1; 585 586 return (nsegs); 587 } 588 589 static int 590 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 591 { 592 device_t dev; 593 struct vq_alloc_info vq_info; 594 595 dev = sc->vtblk_dev; 596 597 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 598 vtblk_vq_intr, sc, &sc->vtblk_vq, 599 "%s request", device_get_nameunit(dev)); 600 601 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 602 } 603 604 static void 605 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 606 { 607 device_t dev; 608 struct disk *dp; 609 610 dev = sc->vtblk_dev; 611 612 sc->vtblk_disk = dp = disk_alloc(); 613 dp->d_open = vtblk_open; 614 dp->d_close = vtblk_close; 615 dp->d_ioctl = vtblk_ioctl; 616 dp->d_strategy = vtblk_strategy; 617 dp->d_name = VTBLK_DISK_NAME; 618 dp->d_unit = device_get_unit(dev); 619 dp->d_drv1 = sc; 620 621 if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0) 622 dp->d_dump = vtblk_dump; 623 624 /* Capacity is always in 512-byte units. */ 625 dp->d_mediasize = blkcfg->capacity * 512; 626 627 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 628 dp->d_sectorsize = blkcfg->blk_size; 629 else 630 dp->d_sectorsize = 512; 631 632 /* 633 * The VirtIO maximum I/O size is given in terms of segments. 634 * However, FreeBSD limits I/O size by logical buffer size, not 635 * by physically contiguous pages. Therefore, we have to assume 636 * no pages are contiguous. This may impose an artificially low 637 * maximum I/O size. But in practice, since QEMU advertises 128 638 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 639 * which is typically greater than MAXPHYS. Eventually we should 640 * just advertise MAXPHYS and split buffers that are too big. 641 * 642 * Note we must subtract one additional segment in case of non 643 * page aligned buffers. 644 */ 645 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 646 PAGE_SIZE; 647 if (dp->d_maxsize < PAGE_SIZE) 648 dp->d_maxsize = PAGE_SIZE; /* XXX */ 649 650 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 651 dp->d_fwsectors = blkcfg->geometry.sectors; 652 dp->d_fwheads = blkcfg->geometry.heads; 653 } 654 655 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 656 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 657 } 658 659 static void 660 vtblk_create_disk(struct vtblk_softc *sc) 661 { 662 struct disk *dp; 663 664 dp = sc->vtblk_disk; 665 666 /* 667 * Retrieving the identification string must be done after 668 * the virtqueue interrupt is setup otherwise it will hang. 669 */ 670 vtblk_get_ident(sc); 671 672 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 673 (uintmax_t) dp->d_mediasize >> 20, 674 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 675 dp->d_sectorsize); 676 677 disk_create(dp, DISK_VERSION); 678 } 679 680 static int 681 vtblk_quiesce(struct vtblk_softc *sc) 682 { 683 int error; 684 685 error = 0; 686 687 VTBLK_LOCK_ASSERT(sc); 688 689 while (!virtqueue_empty(sc->vtblk_vq)) { 690 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 691 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 692 error = EBUSY; 693 break; 694 } 695 } 696 697 return (error); 698 } 699 700 static void 701 vtblk_startio(struct vtblk_softc *sc) 702 { 703 struct virtqueue *vq; 704 struct vtblk_request *req; 705 int enq; 706 707 vq = sc->vtblk_vq; 708 enq = 0; 709 710 VTBLK_LOCK_ASSERT(sc); 711 712 while (!virtqueue_full(vq)) { 713 if ((req = vtblk_dequeue_ready(sc)) == NULL) 714 req = vtblk_bio_request(sc); 715 if (req == NULL) 716 break; 717 718 if (vtblk_execute_request(sc, req) != 0) { 719 vtblk_enqueue_ready(sc, req); 720 break; 721 } 722 723 enq++; 724 } 725 726 if (enq > 0) 727 virtqueue_notify(vq); 728 } 729 730 static struct vtblk_request * 731 vtblk_bio_request(struct vtblk_softc *sc) 732 { 733 struct bio_queue_head *bioq; 734 struct vtblk_request *req; 735 struct bio *bp; 736 737 bioq = &sc->vtblk_bioq; 738 739 if (bioq_first(bioq) == NULL) 740 return (NULL); 741 742 req = vtblk_dequeue_request(sc); 743 if (req == NULL) 744 return (NULL); 745 746 bp = bioq_takefirst(bioq); 747 req->vbr_bp = bp; 748 req->vbr_ack = -1; 749 req->vbr_hdr.ioprio = 1; 750 751 switch (bp->bio_cmd) { 752 case BIO_FLUSH: 753 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 754 break; 755 case BIO_READ: 756 req->vbr_hdr.type = VIRTIO_BLK_T_IN; 757 req->vbr_hdr.sector = bp->bio_offset / 512; 758 break; 759 case BIO_WRITE: 760 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 761 req->vbr_hdr.sector = bp->bio_offset / 512; 762 break; 763 default: 764 panic("%s: bio with unhandled cmd: %d", __FUNCTION__, 765 bp->bio_cmd); 766 } 767 768 if (bp->bio_flags & BIO_ORDERED) 769 req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER; 770 771 return (req); 772 } 773 774 static int 775 vtblk_execute_request(struct vtblk_softc *sc, struct vtblk_request *req) 776 { 777 struct sglist *sg; 778 struct bio *bp; 779 int readable, writable, error; 780 781 sg = sc->vtblk_sglist; 782 bp = req->vbr_bp; 783 writable = 0; 784 785 VTBLK_LOCK_ASSERT(sc); 786 787 sglist_reset(sg); 788 789 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 790 791 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 792 error = sglist_append(sg, bp->bio_data, bp->bio_bcount); 793 if (error || sg->sg_nseg == sg->sg_maxseg) 794 panic("%s: data buffer too big bio:%p error:%d", 795 __FUNCTION__, bp, error); 796 797 /* BIO_READ means the host writes into our buffer. */ 798 if (bp->bio_cmd == BIO_READ) 799 writable = sg->sg_nseg - 1; 800 } 801 802 writable++; 803 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 804 805 readable = sg->sg_nseg - writable; 806 807 return (virtqueue_enqueue(sc->vtblk_vq, req, sg, readable, writable)); 808 } 809 810 static int 811 vtblk_vq_intr(void *xsc) 812 { 813 struct vtblk_softc *sc; 814 815 sc = xsc; 816 817 virtqueue_disable_intr(sc->vtblk_vq); 818 taskqueue_enqueue_fast(sc->vtblk_tq, &sc->vtblk_intr_task); 819 820 return (1); 821 } 822 823 static void 824 vtblk_intr_task(void *arg, int pending) 825 { 826 struct vtblk_softc *sc; 827 struct virtqueue *vq; 828 829 sc = arg; 830 vq = sc->vtblk_vq; 831 832 VTBLK_LOCK(sc); 833 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 834 VTBLK_UNLOCK(sc); 835 return; 836 } 837 838 vtblk_finish_completed(sc); 839 840 if ((sc->vtblk_flags & VTBLK_FLAG_SUSPEND) == 0) 841 vtblk_startio(sc); 842 else 843 wakeup(&sc->vtblk_vq); 844 845 if (virtqueue_enable_intr(vq) != 0) { 846 virtqueue_disable_intr(vq); 847 VTBLK_UNLOCK(sc); 848 taskqueue_enqueue_fast(sc->vtblk_tq, 849 &sc->vtblk_intr_task); 850 return; 851 } 852 853 VTBLK_UNLOCK(sc); 854 } 855 856 static void 857 vtblk_stop(struct vtblk_softc *sc) 858 { 859 860 virtqueue_disable_intr(sc->vtblk_vq); 861 virtio_stop(sc->vtblk_dev); 862 } 863 864 static void 865 vtblk_get_ident(struct vtblk_softc *sc) 866 { 867 struct bio buf; 868 struct disk *dp; 869 struct vtblk_request *req; 870 int len, error; 871 872 dp = sc->vtblk_disk; 873 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 874 875 if (vtblk_no_ident != 0) 876 return; 877 878 req = vtblk_dequeue_request(sc); 879 if (req == NULL) 880 return; 881 882 req->vbr_ack = -1; 883 req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; 884 req->vbr_hdr.ioprio = 1; 885 req->vbr_hdr.sector = 0; 886 887 req->vbr_bp = &buf; 888 bzero(&buf, sizeof(struct bio)); 889 890 buf.bio_cmd = BIO_READ; 891 buf.bio_data = dp->d_ident; 892 buf.bio_bcount = len; 893 894 VTBLK_LOCK(sc); 895 error = vtblk_poll_request(sc, req); 896 VTBLK_UNLOCK(sc); 897 898 vtblk_enqueue_request(sc, req); 899 900 if (error) { 901 device_printf(sc->vtblk_dev, 902 "error getting device identifier: %d\n", error); 903 } 904 } 905 906 static void 907 vtblk_prepare_dump(struct vtblk_softc *sc) 908 { 909 device_t dev; 910 struct virtqueue *vq; 911 912 dev = sc->vtblk_dev; 913 vq = sc->vtblk_vq; 914 915 vtblk_stop(sc); 916 917 /* 918 * Drain all requests caught in-flight in the virtqueue, 919 * skipping biodone(). When dumping, only one request is 920 * outstanding at a time, and we just poll the virtqueue 921 * for the response. 922 */ 923 vtblk_drain_vq(sc, 1); 924 925 if (virtio_reinit(dev, sc->vtblk_features) != 0) 926 panic("cannot reinit VirtIO block device during dump"); 927 928 virtqueue_disable_intr(vq); 929 virtio_reinit_complete(dev); 930 } 931 932 static int 933 vtblk_write_dump(struct vtblk_softc *sc, void *virtual, off_t offset, 934 size_t length) 935 { 936 struct bio buf; 937 struct vtblk_request *req; 938 939 req = &sc->vtblk_dump_request; 940 req->vbr_ack = -1; 941 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 942 req->vbr_hdr.ioprio = 1; 943 req->vbr_hdr.sector = offset / 512; 944 945 req->vbr_bp = &buf; 946 bzero(&buf, sizeof(struct bio)); 947 948 buf.bio_cmd = BIO_WRITE; 949 buf.bio_data = virtual; 950 buf.bio_bcount = length; 951 952 return (vtblk_poll_request(sc, req)); 953 } 954 955 static int 956 vtblk_flush_dump(struct vtblk_softc *sc) 957 { 958 struct bio buf; 959 struct vtblk_request *req; 960 961 req = &sc->vtblk_dump_request; 962 req->vbr_ack = -1; 963 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 964 req->vbr_hdr.ioprio = 1; 965 req->vbr_hdr.sector = 0; 966 967 req->vbr_bp = &buf; 968 bzero(&buf, sizeof(struct bio)); 969 970 buf.bio_cmd = BIO_FLUSH; 971 972 return (vtblk_poll_request(sc, req)); 973 } 974 975 static int 976 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 977 { 978 struct virtqueue *vq; 979 struct vtblk_request *r; 980 int error; 981 982 vq = sc->vtblk_vq; 983 984 if (!virtqueue_empty(vq)) 985 return (EBUSY); 986 987 error = vtblk_execute_request(sc, req); 988 if (error) 989 return (error); 990 991 virtqueue_notify(vq); 992 993 r = virtqueue_poll(vq, NULL); 994 KASSERT(r == req, ("unexpected request response: %p/%p", r, req)); 995 996 error = vtblk_request_error(req); 997 if (error && bootverbose) { 998 device_printf(sc->vtblk_dev, 999 "%s: IO error: %d\n", __FUNCTION__, error); 1000 } 1001 1002 return (error); 1003 } 1004 1005 static void 1006 vtblk_finish_completed(struct vtblk_softc *sc) 1007 { 1008 struct vtblk_request *req; 1009 struct bio *bp; 1010 int error; 1011 1012 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1013 bp = req->vbr_bp; 1014 1015 error = vtblk_request_error(req); 1016 if (error) 1017 disk_err(bp, "hard error", -1, 1); 1018 1019 vtblk_finish_bio(bp, error); 1020 vtblk_enqueue_request(sc, req); 1021 } 1022 } 1023 1024 static void 1025 vtblk_drain_vq(struct vtblk_softc *sc, int skip_done) 1026 { 1027 struct virtqueue *vq; 1028 struct vtblk_request *req; 1029 int last; 1030 1031 vq = sc->vtblk_vq; 1032 last = 0; 1033 1034 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1035 if (!skip_done) 1036 vtblk_finish_bio(req->vbr_bp, ENXIO); 1037 1038 vtblk_enqueue_request(sc, req); 1039 } 1040 1041 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1042 } 1043 1044 static void 1045 vtblk_drain(struct vtblk_softc *sc) 1046 { 1047 struct bio_queue_head *bioq; 1048 struct vtblk_request *req; 1049 struct bio *bp; 1050 1051 bioq = &sc->vtblk_bioq; 1052 1053 if (sc->vtblk_vq != NULL) { 1054 vtblk_finish_completed(sc); 1055 vtblk_drain_vq(sc, 0); 1056 } 1057 1058 while ((req = vtblk_dequeue_ready(sc)) != NULL) { 1059 vtblk_finish_bio(req->vbr_bp, ENXIO); 1060 vtblk_enqueue_request(sc, req); 1061 } 1062 1063 while (bioq_first(bioq) != NULL) { 1064 bp = bioq_takefirst(bioq); 1065 vtblk_finish_bio(bp, ENXIO); 1066 } 1067 1068 vtblk_free_requests(sc); 1069 } 1070 1071 #ifdef INVARIANTS 1072 static void 1073 vtblk_request_invariants(struct vtblk_request *req) 1074 { 1075 int hdr_nsegs, ack_nsegs; 1076 1077 hdr_nsegs = sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)); 1078 ack_nsegs = sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)); 1079 1080 KASSERT(hdr_nsegs == 1, ("request header crossed page boundary")); 1081 KASSERT(ack_nsegs == 1, ("request ack crossed page boundary")); 1082 } 1083 #endif 1084 1085 static int 1086 vtblk_alloc_requests(struct vtblk_softc *sc) 1087 { 1088 struct vtblk_request *req; 1089 int i, nreqs; 1090 1091 nreqs = virtqueue_size(sc->vtblk_vq); 1092 1093 /* 1094 * Preallocate sufficient requests to keep the virtqueue full. Each 1095 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 1096 * the number allocated when indirect descriptors are not available. 1097 */ 1098 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 1099 nreqs /= VTBLK_MIN_SEGMENTS; 1100 1101 for (i = 0; i < nreqs; i++) { 1102 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 1103 if (req == NULL) 1104 return (ENOMEM); 1105 1106 #ifdef INVARIANTS 1107 vtblk_request_invariants(req); 1108 #endif 1109 1110 sc->vtblk_request_count++; 1111 vtblk_enqueue_request(sc, req); 1112 } 1113 1114 return (0); 1115 } 1116 1117 static void 1118 vtblk_free_requests(struct vtblk_softc *sc) 1119 { 1120 struct vtblk_request *req; 1121 1122 KASSERT(TAILQ_EMPTY(&sc->vtblk_req_ready), 1123 ("ready requests left on queue")); 1124 1125 while ((req = vtblk_dequeue_request(sc)) != NULL) { 1126 sc->vtblk_request_count--; 1127 free(req, M_DEVBUF); 1128 } 1129 1130 KASSERT(sc->vtblk_request_count == 0, 1131 ("leaked requests: %d", sc->vtblk_request_count)); 1132 } 1133 1134 static struct vtblk_request * 1135 vtblk_dequeue_request(struct vtblk_softc *sc) 1136 { 1137 struct vtblk_request *req; 1138 1139 req = TAILQ_FIRST(&sc->vtblk_req_free); 1140 if (req != NULL) 1141 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 1142 1143 return (req); 1144 } 1145 1146 static void 1147 vtblk_enqueue_request(struct vtblk_softc *sc, struct vtblk_request *req) 1148 { 1149 1150 bzero(req, sizeof(struct vtblk_request)); 1151 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 1152 } 1153 1154 static struct vtblk_request * 1155 vtblk_dequeue_ready(struct vtblk_softc *sc) 1156 { 1157 struct vtblk_request *req; 1158 1159 req = TAILQ_FIRST(&sc->vtblk_req_ready); 1160 if (req != NULL) 1161 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 1162 1163 return (req); 1164 } 1165 1166 static void 1167 vtblk_enqueue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 1168 { 1169 1170 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 1171 } 1172 1173 static int 1174 vtblk_request_error(struct vtblk_request *req) 1175 { 1176 int error; 1177 1178 switch (req->vbr_ack) { 1179 case VIRTIO_BLK_S_OK: 1180 error = 0; 1181 break; 1182 case VIRTIO_BLK_S_UNSUPP: 1183 error = ENOTSUP; 1184 break; 1185 default: 1186 error = EIO; 1187 break; 1188 } 1189 1190 return (error); 1191 } 1192 1193 static void 1194 vtblk_finish_bio(struct bio *bp, int error) 1195 { 1196 1197 if (error) { 1198 bp->bio_resid = bp->bio_bcount; 1199 bp->bio_error = error; 1200 bp->bio_flags |= BIO_ERROR; 1201 } 1202 1203 biodone(bp); 1204 } 1205