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 #define VTBLK_FLAG_BARRIER 0x0020 76 77 struct virtqueue *vtblk_vq; 78 struct sglist *vtblk_sglist; 79 struct disk *vtblk_disk; 80 81 struct bio_queue_head vtblk_bioq; 82 TAILQ_HEAD(, vtblk_request) 83 vtblk_req_free; 84 TAILQ_HEAD(, vtblk_request) 85 vtblk_req_ready; 86 struct vtblk_request *vtblk_req_ordered; 87 88 struct taskqueue *vtblk_tq; 89 struct task vtblk_intr_task; 90 91 int vtblk_max_nsegs; 92 int vtblk_request_count; 93 94 struct vtblk_request vtblk_dump_request; 95 }; 96 97 static struct virtio_feature_desc vtblk_feature_desc[] = { 98 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 99 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 100 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 101 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 102 { VIRTIO_BLK_F_RO, "ReadOnly" }, 103 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 104 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 105 { VIRTIO_BLK_F_FLUSH, "FlushCmd" }, 106 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 107 108 { 0, NULL } 109 }; 110 111 static int vtblk_modevent(module_t, int, void *); 112 113 static int vtblk_probe(device_t); 114 static int vtblk_attach(device_t); 115 static int vtblk_detach(device_t); 116 static int vtblk_suspend(device_t); 117 static int vtblk_resume(device_t); 118 static int vtblk_shutdown(device_t); 119 120 static int vtblk_open(struct disk *); 121 static int vtblk_close(struct disk *); 122 static int vtblk_ioctl(struct disk *, u_long, void *, int, 123 struct thread *); 124 static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); 125 static void vtblk_strategy(struct bio *); 126 127 static void vtblk_negotiate_features(struct vtblk_softc *); 128 static int vtblk_maximum_segments(struct vtblk_softc *, 129 struct virtio_blk_config *); 130 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 131 static void vtblk_alloc_disk(struct vtblk_softc *, 132 struct virtio_blk_config *); 133 static void vtblk_create_disk(struct vtblk_softc *); 134 135 static int vtblk_quiesce(struct vtblk_softc *); 136 static void vtblk_startio(struct vtblk_softc *); 137 static struct vtblk_request * vtblk_bio_request(struct vtblk_softc *); 138 static int vtblk_execute_request(struct vtblk_softc *, 139 struct vtblk_request *); 140 141 static int vtblk_vq_intr(void *); 142 static void vtblk_intr_task(void *, int); 143 144 static void vtblk_stop(struct vtblk_softc *); 145 146 static void vtblk_get_ident(struct vtblk_softc *); 147 static void vtblk_prepare_dump(struct vtblk_softc *); 148 static int vtblk_write_dump(struct vtblk_softc *, void *, off_t, size_t); 149 static int vtblk_flush_dump(struct vtblk_softc *); 150 static int vtblk_poll_request(struct vtblk_softc *, 151 struct vtblk_request *); 152 153 static void vtblk_finish_completed(struct vtblk_softc *); 154 static void vtblk_drain_vq(struct vtblk_softc *, int); 155 static void vtblk_drain(struct vtblk_softc *); 156 157 static int vtblk_alloc_requests(struct vtblk_softc *); 158 static void vtblk_free_requests(struct vtblk_softc *); 159 static struct vtblk_request * vtblk_dequeue_request(struct vtblk_softc *); 160 static void vtblk_enqueue_request(struct vtblk_softc *, 161 struct vtblk_request *); 162 163 static struct vtblk_request * vtblk_dequeue_ready(struct vtblk_softc *); 164 static void vtblk_enqueue_ready(struct vtblk_softc *, 165 struct vtblk_request *); 166 167 static int vtblk_request_error(struct vtblk_request *); 168 static void vtblk_finish_bio(struct bio *, int); 169 170 /* Tunables. */ 171 static int vtblk_no_ident = 0; 172 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 173 174 /* Features desired/implemented by this driver. */ 175 #define VTBLK_FEATURES \ 176 (VIRTIO_BLK_F_BARRIER | \ 177 VIRTIO_BLK_F_SIZE_MAX | \ 178 VIRTIO_BLK_F_SEG_MAX | \ 179 VIRTIO_BLK_F_GEOMETRY | \ 180 VIRTIO_BLK_F_RO | \ 181 VIRTIO_BLK_F_BLK_SIZE | \ 182 VIRTIO_BLK_F_FLUSH | \ 183 VIRTIO_RING_F_INDIRECT_DESC) 184 185 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 186 #define VTBLK_LOCK_INIT(_sc, _name) \ 187 mtx_init(VTBLK_MTX((_sc)), (_name), \ 188 "VTBLK Lock", MTX_DEF) 189 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 190 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 191 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 192 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 193 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 194 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 195 196 #define VTBLK_DISK_NAME "vtbd" 197 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 198 199 /* 200 * Each block request uses at least two segments - one for the header 201 * and one for the status. 202 */ 203 #define VTBLK_MIN_SEGMENTS 2 204 205 static device_method_t vtblk_methods[] = { 206 /* Device methods. */ 207 DEVMETHOD(device_probe, vtblk_probe), 208 DEVMETHOD(device_attach, vtblk_attach), 209 DEVMETHOD(device_detach, vtblk_detach), 210 DEVMETHOD(device_suspend, vtblk_suspend), 211 DEVMETHOD(device_resume, vtblk_resume), 212 DEVMETHOD(device_shutdown, vtblk_shutdown), 213 214 DEVMETHOD_END 215 }; 216 217 static driver_t vtblk_driver = { 218 "vtblk", 219 vtblk_methods, 220 sizeof(struct vtblk_softc) 221 }; 222 static devclass_t vtblk_devclass; 223 224 DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, 225 vtblk_modevent, 0); 226 MODULE_VERSION(virtio_blk, 1); 227 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 228 229 static int 230 vtblk_modevent(module_t mod, int type, void *unused) 231 { 232 int error; 233 234 error = 0; 235 236 switch (type) { 237 case MOD_LOAD: 238 case MOD_QUIESCE: 239 case MOD_UNLOAD: 240 case MOD_SHUTDOWN: 241 break; 242 default: 243 error = EOPNOTSUPP; 244 break; 245 } 246 247 return (error); 248 } 249 250 static int 251 vtblk_probe(device_t dev) 252 { 253 254 if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) 255 return (ENXIO); 256 257 device_set_desc(dev, "VirtIO Block Adapter"); 258 259 return (BUS_PROBE_DEFAULT); 260 } 261 262 static int 263 vtblk_attach(device_t dev) 264 { 265 struct vtblk_softc *sc; 266 struct virtio_blk_config blkcfg; 267 int error; 268 269 sc = device_get_softc(dev); 270 sc->vtblk_dev = dev; 271 272 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 273 274 bioq_init(&sc->vtblk_bioq); 275 TAILQ_INIT(&sc->vtblk_req_free); 276 TAILQ_INIT(&sc->vtblk_req_ready); 277 278 virtio_set_feature_desc(dev, vtblk_feature_desc); 279 vtblk_negotiate_features(sc); 280 281 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 282 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 283 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 284 sc->vtblk_flags |= VTBLK_FLAG_READONLY; 285 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 286 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 287 288 /* Get local copy of config. */ 289 virtio_read_device_config(dev, 0, &blkcfg, 290 sizeof(struct virtio_blk_config)); 291 292 /* 293 * With the current sglist(9) implementation, it is not easy 294 * for us to support a maximum segment size as adjacent 295 * segments are coalesced. For now, just make sure it's larger 296 * than the maximum supported transfer size. 297 */ 298 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 299 if (blkcfg.size_max < MAXPHYS) { 300 error = ENOTSUP; 301 device_printf(dev, "host requires unsupported " 302 "maximum segment size feature\n"); 303 goto fail; 304 } 305 } 306 307 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 308 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 309 error = EINVAL; 310 device_printf(dev, "fewer than minimum number of segments " 311 "allowed: %d\n", sc->vtblk_max_nsegs); 312 goto fail; 313 } 314 315 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 316 if (sc->vtblk_sglist == NULL) { 317 error = ENOMEM; 318 device_printf(dev, "cannot allocate sglist\n"); 319 goto fail; 320 } 321 322 error = vtblk_alloc_virtqueue(sc); 323 if (error) { 324 device_printf(dev, "cannot allocate virtqueue\n"); 325 goto fail; 326 } 327 328 error = vtblk_alloc_requests(sc); 329 if (error) { 330 device_printf(dev, "cannot preallocate requests\n"); 331 goto fail; 332 } 333 334 vtblk_alloc_disk(sc, &blkcfg); 335 336 TASK_INIT(&sc->vtblk_intr_task, 0, vtblk_intr_task, sc); 337 sc->vtblk_tq = taskqueue_create_fast("vtblk_taskq", M_NOWAIT, 338 taskqueue_thread_enqueue, &sc->vtblk_tq); 339 if (sc->vtblk_tq == NULL) { 340 error = ENOMEM; 341 device_printf(dev, "cannot allocate taskqueue\n"); 342 goto fail; 343 } 344 345 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 346 if (error) { 347 device_printf(dev, "cannot setup virtqueue interrupt\n"); 348 goto fail; 349 } 350 351 taskqueue_start_threads(&sc->vtblk_tq, 1, PI_DISK, "%s taskq", 352 device_get_nameunit(dev)); 353 354 vtblk_create_disk(sc); 355 356 virtqueue_enable_intr(sc->vtblk_vq); 357 358 fail: 359 if (error) 360 vtblk_detach(dev); 361 362 return (error); 363 } 364 365 static int 366 vtblk_detach(device_t dev) 367 { 368 struct vtblk_softc *sc; 369 370 sc = device_get_softc(dev); 371 372 VTBLK_LOCK(sc); 373 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 374 if (device_is_attached(dev)) 375 vtblk_stop(sc); 376 VTBLK_UNLOCK(sc); 377 378 if (sc->vtblk_tq != NULL) { 379 taskqueue_drain(sc->vtblk_tq, &sc->vtblk_intr_task); 380 taskqueue_free(sc->vtblk_tq); 381 sc->vtblk_tq = NULL; 382 } 383 384 vtblk_drain(sc); 385 386 if (sc->vtblk_disk != NULL) { 387 disk_destroy(sc->vtblk_disk); 388 sc->vtblk_disk = NULL; 389 } 390 391 if (sc->vtblk_sglist != NULL) { 392 sglist_free(sc->vtblk_sglist); 393 sc->vtblk_sglist = NULL; 394 } 395 396 VTBLK_LOCK_DESTROY(sc); 397 398 return (0); 399 } 400 401 static int 402 vtblk_suspend(device_t dev) 403 { 404 struct vtblk_softc *sc; 405 int error; 406 407 sc = device_get_softc(dev); 408 409 VTBLK_LOCK(sc); 410 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 411 /* XXX BMV: virtio_stop(), etc needed here? */ 412 error = vtblk_quiesce(sc); 413 if (error) 414 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 415 VTBLK_UNLOCK(sc); 416 417 return (error); 418 } 419 420 static int 421 vtblk_resume(device_t dev) 422 { 423 struct vtblk_softc *sc; 424 425 sc = device_get_softc(dev); 426 427 VTBLK_LOCK(sc); 428 /* XXX BMV: virtio_reinit(), etc needed here? */ 429 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 430 vtblk_startio(sc); 431 VTBLK_UNLOCK(sc); 432 433 return (0); 434 } 435 436 static int 437 vtblk_shutdown(device_t dev) 438 { 439 440 return (0); 441 } 442 443 static int 444 vtblk_open(struct disk *dp) 445 { 446 struct vtblk_softc *sc; 447 448 if ((sc = dp->d_drv1) == NULL) 449 return (ENXIO); 450 451 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 452 } 453 454 static int 455 vtblk_close(struct disk *dp) 456 { 457 struct vtblk_softc *sc; 458 459 if ((sc = dp->d_drv1) == NULL) 460 return (ENXIO); 461 462 return (0); 463 } 464 465 static int 466 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 467 struct thread *td) 468 { 469 struct vtblk_softc *sc; 470 471 if ((sc = dp->d_drv1) == NULL) 472 return (ENXIO); 473 474 return (ENOTTY); 475 } 476 477 static int 478 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 479 size_t length) 480 { 481 struct disk *dp; 482 struct vtblk_softc *sc; 483 int error; 484 485 dp = arg; 486 487 if ((sc = dp->d_drv1) == NULL) 488 return (ENXIO); 489 490 VTBLK_LOCK(sc); 491 492 if ((sc->vtblk_flags & VTBLK_FLAG_DUMPING) == 0) { 493 vtblk_prepare_dump(sc); 494 sc->vtblk_flags |= VTBLK_FLAG_DUMPING; 495 } 496 497 if (length > 0) 498 error = vtblk_write_dump(sc, virtual, offset, length); 499 else if (virtual == NULL && offset == 0) 500 error = vtblk_flush_dump(sc); 501 else { 502 error = EINVAL; 503 sc->vtblk_flags &= ~VTBLK_FLAG_DUMPING; 504 } 505 506 VTBLK_UNLOCK(sc); 507 508 return (error); 509 } 510 511 static void 512 vtblk_strategy(struct bio *bp) 513 { 514 struct vtblk_softc *sc; 515 516 if ((sc = bp->bio_disk->d_drv1) == NULL) { 517 vtblk_finish_bio(bp, EINVAL); 518 return; 519 } 520 521 /* 522 * Fail any write if RO. Unfortunately, there does not seem to 523 * be a better way to report our readonly'ness to GEOM above. 524 */ 525 if (sc->vtblk_flags & VTBLK_FLAG_READONLY && 526 (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_FLUSH)) { 527 vtblk_finish_bio(bp, EROFS); 528 return; 529 } 530 531 #ifdef INVARIANTS 532 /* 533 * Prevent read/write buffers spanning too many segments from 534 * getting into the queue. This should only trip if d_maxsize 535 * was incorrectly set. 536 */ 537 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 538 int nsegs, max_nsegs; 539 540 nsegs = sglist_count(bp->bio_data, bp->bio_bcount); 541 max_nsegs = sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS; 542 543 KASSERT(nsegs <= max_nsegs, 544 ("bio %p spanned too many segments: %d, max: %d", 545 bp, nsegs, max_nsegs)); 546 } 547 #endif 548 549 VTBLK_LOCK(sc); 550 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 551 vtblk_finish_bio(bp, ENXIO); 552 else { 553 bioq_disksort(&sc->vtblk_bioq, bp); 554 555 if ((sc->vtblk_flags & VTBLK_FLAG_SUSPEND) == 0) 556 vtblk_startio(sc); 557 } 558 VTBLK_UNLOCK(sc); 559 } 560 561 static void 562 vtblk_negotiate_features(struct vtblk_softc *sc) 563 { 564 device_t dev; 565 uint64_t features; 566 567 dev = sc->vtblk_dev; 568 features = VTBLK_FEATURES; 569 570 sc->vtblk_features = virtio_negotiate_features(dev, features); 571 } 572 573 static int 574 vtblk_maximum_segments(struct vtblk_softc *sc, 575 struct virtio_blk_config *blkcfg) 576 { 577 device_t dev; 578 int nsegs; 579 580 dev = sc->vtblk_dev; 581 nsegs = VTBLK_MIN_SEGMENTS; 582 583 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 584 nsegs += MIN(blkcfg->seg_max, MAXPHYS / PAGE_SIZE + 1); 585 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 586 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 587 } else 588 nsegs += 1; 589 590 return (nsegs); 591 } 592 593 static int 594 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 595 { 596 device_t dev; 597 struct vq_alloc_info vq_info; 598 599 dev = sc->vtblk_dev; 600 601 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 602 vtblk_vq_intr, sc, &sc->vtblk_vq, 603 "%s request", device_get_nameunit(dev)); 604 605 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 606 } 607 608 static void 609 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 610 { 611 device_t dev; 612 struct disk *dp; 613 614 dev = sc->vtblk_dev; 615 616 sc->vtblk_disk = dp = disk_alloc(); 617 dp->d_open = vtblk_open; 618 dp->d_close = vtblk_close; 619 dp->d_ioctl = vtblk_ioctl; 620 dp->d_strategy = vtblk_strategy; 621 dp->d_name = VTBLK_DISK_NAME; 622 dp->d_unit = device_get_unit(dev); 623 dp->d_drv1 = sc; 624 625 if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0) 626 dp->d_dump = vtblk_dump; 627 628 /* Capacity is always in 512-byte units. */ 629 dp->d_mediasize = blkcfg->capacity * 512; 630 631 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 632 dp->d_sectorsize = blkcfg->blk_size; 633 else 634 dp->d_sectorsize = 512; 635 636 /* 637 * The VirtIO maximum I/O size is given in terms of segments. 638 * However, FreeBSD limits I/O size by logical buffer size, not 639 * by physically contiguous pages. Therefore, we have to assume 640 * no pages are contiguous. This may impose an artificially low 641 * maximum I/O size. But in practice, since QEMU advertises 128 642 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 643 * which is typically greater than MAXPHYS. Eventually we should 644 * just advertise MAXPHYS and split buffers that are too big. 645 * 646 * Note we must subtract one additional segment in case of non 647 * page aligned buffers. 648 */ 649 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 650 PAGE_SIZE; 651 if (dp->d_maxsize < PAGE_SIZE) 652 dp->d_maxsize = PAGE_SIZE; /* XXX */ 653 654 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 655 dp->d_fwsectors = blkcfg->geometry.sectors; 656 dp->d_fwheads = blkcfg->geometry.heads; 657 } 658 659 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 660 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 661 } 662 663 static void 664 vtblk_create_disk(struct vtblk_softc *sc) 665 { 666 struct disk *dp; 667 668 dp = sc->vtblk_disk; 669 670 /* 671 * Retrieving the identification string must be done after 672 * the virtqueue interrupt is setup otherwise it will hang. 673 */ 674 vtblk_get_ident(sc); 675 676 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 677 (uintmax_t) dp->d_mediasize >> 20, 678 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 679 dp->d_sectorsize); 680 681 disk_create(dp, DISK_VERSION); 682 } 683 684 static int 685 vtblk_quiesce(struct vtblk_softc *sc) 686 { 687 int error; 688 689 error = 0; 690 691 VTBLK_LOCK_ASSERT(sc); 692 693 while (!virtqueue_empty(sc->vtblk_vq)) { 694 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 695 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 696 error = EBUSY; 697 break; 698 } 699 } 700 701 return (error); 702 } 703 704 static void 705 vtblk_startio(struct vtblk_softc *sc) 706 { 707 struct virtqueue *vq; 708 struct vtblk_request *req; 709 int enq; 710 711 vq = sc->vtblk_vq; 712 enq = 0; 713 714 VTBLK_LOCK_ASSERT(sc); 715 716 while (!virtqueue_full(vq)) { 717 if ((req = vtblk_dequeue_ready(sc)) == NULL) 718 req = vtblk_bio_request(sc); 719 if (req == NULL) 720 break; 721 722 if (vtblk_execute_request(sc, req) != 0) { 723 vtblk_enqueue_ready(sc, req); 724 break; 725 } 726 727 enq++; 728 } 729 730 if (enq > 0) 731 virtqueue_notify(vq); 732 } 733 734 static struct vtblk_request * 735 vtblk_bio_request(struct vtblk_softc *sc) 736 { 737 struct bio_queue_head *bioq; 738 struct vtblk_request *req; 739 struct bio *bp; 740 741 bioq = &sc->vtblk_bioq; 742 743 if (bioq_first(bioq) == NULL) 744 return (NULL); 745 746 req = vtblk_dequeue_request(sc); 747 if (req == NULL) 748 return (NULL); 749 750 bp = bioq_takefirst(bioq); 751 req->vbr_bp = bp; 752 req->vbr_ack = -1; 753 req->vbr_hdr.ioprio = 1; 754 755 switch (bp->bio_cmd) { 756 case BIO_FLUSH: 757 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 758 break; 759 case BIO_READ: 760 req->vbr_hdr.type = VIRTIO_BLK_T_IN; 761 req->vbr_hdr.sector = bp->bio_offset / 512; 762 break; 763 case BIO_WRITE: 764 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 765 req->vbr_hdr.sector = bp->bio_offset / 512; 766 break; 767 default: 768 panic("%s: bio with unhandled cmd: %d", __FUNCTION__, 769 bp->bio_cmd); 770 } 771 772 return (req); 773 } 774 775 static int 776 vtblk_execute_request(struct vtblk_softc *sc, struct vtblk_request *req) 777 { 778 struct virtqueue *vq; 779 struct sglist *sg; 780 struct bio *bp; 781 int ordered, readable, writable, error; 782 783 vq = sc->vtblk_vq; 784 sg = sc->vtblk_sglist; 785 bp = req->vbr_bp; 786 ordered = 0; 787 writable = 0; 788 789 VTBLK_LOCK_ASSERT(sc); 790 791 /* 792 * Wait until the ordered request completes before 793 * executing subsequent requests. 794 */ 795 if (sc->vtblk_req_ordered != NULL) 796 return (EBUSY); 797 798 if (bp->bio_flags & BIO_ORDERED) { 799 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 800 /* 801 * This request will be executed once all 802 * the in-flight requests are completed. 803 */ 804 if (!virtqueue_empty(vq)) 805 return (EBUSY); 806 ordered = 1; 807 } else 808 req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER; 809 } 810 811 sglist_reset(sg); 812 813 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 814 815 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 816 error = sglist_append(sg, bp->bio_data, bp->bio_bcount); 817 if (error || sg->sg_nseg == sg->sg_maxseg) 818 panic("%s: data buffer too big bio:%p error:%d", 819 __FUNCTION__, bp, error); 820 821 /* BIO_READ means the host writes into our buffer. */ 822 if (bp->bio_cmd == BIO_READ) 823 writable = sg->sg_nseg - 1; 824 } 825 826 writable++; 827 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 828 readable = sg->sg_nseg - writable; 829 830 error = virtqueue_enqueue(vq, req, sg, readable, writable); 831 if (error == 0 && ordered) 832 sc->vtblk_req_ordered = req; 833 834 return (error); 835 } 836 837 static int 838 vtblk_vq_intr(void *xsc) 839 { 840 struct vtblk_softc *sc; 841 842 sc = xsc; 843 844 virtqueue_disable_intr(sc->vtblk_vq); 845 taskqueue_enqueue_fast(sc->vtblk_tq, &sc->vtblk_intr_task); 846 847 return (1); 848 } 849 850 static void 851 vtblk_intr_task(void *arg, int pending) 852 { 853 struct vtblk_softc *sc; 854 struct virtqueue *vq; 855 856 sc = arg; 857 vq = sc->vtblk_vq; 858 859 VTBLK_LOCK(sc); 860 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 861 VTBLK_UNLOCK(sc); 862 return; 863 } 864 865 vtblk_finish_completed(sc); 866 867 if ((sc->vtblk_flags & VTBLK_FLAG_SUSPEND) == 0) 868 vtblk_startio(sc); 869 else 870 wakeup(&sc->vtblk_vq); 871 872 if (virtqueue_enable_intr(vq) != 0) { 873 virtqueue_disable_intr(vq); 874 VTBLK_UNLOCK(sc); 875 taskqueue_enqueue_fast(sc->vtblk_tq, 876 &sc->vtblk_intr_task); 877 return; 878 } 879 880 VTBLK_UNLOCK(sc); 881 } 882 883 static void 884 vtblk_stop(struct vtblk_softc *sc) 885 { 886 887 virtqueue_disable_intr(sc->vtblk_vq); 888 virtio_stop(sc->vtblk_dev); 889 } 890 891 static void 892 vtblk_get_ident(struct vtblk_softc *sc) 893 { 894 struct bio buf; 895 struct disk *dp; 896 struct vtblk_request *req; 897 int len, error; 898 899 dp = sc->vtblk_disk; 900 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 901 902 if (vtblk_no_ident != 0) 903 return; 904 905 req = vtblk_dequeue_request(sc); 906 if (req == NULL) 907 return; 908 909 req->vbr_ack = -1; 910 req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; 911 req->vbr_hdr.ioprio = 1; 912 req->vbr_hdr.sector = 0; 913 914 req->vbr_bp = &buf; 915 bzero(&buf, sizeof(struct bio)); 916 917 buf.bio_cmd = BIO_READ; 918 buf.bio_data = dp->d_ident; 919 buf.bio_bcount = len; 920 921 VTBLK_LOCK(sc); 922 error = vtblk_poll_request(sc, req); 923 VTBLK_UNLOCK(sc); 924 925 vtblk_enqueue_request(sc, req); 926 927 if (error) { 928 device_printf(sc->vtblk_dev, 929 "error getting device identifier: %d\n", error); 930 } 931 } 932 933 static void 934 vtblk_prepare_dump(struct vtblk_softc *sc) 935 { 936 device_t dev; 937 struct virtqueue *vq; 938 939 dev = sc->vtblk_dev; 940 vq = sc->vtblk_vq; 941 942 vtblk_stop(sc); 943 944 /* 945 * Drain all requests caught in-flight in the virtqueue, 946 * skipping biodone(). When dumping, only one request is 947 * outstanding at a time, and we just poll the virtqueue 948 * for the response. 949 */ 950 vtblk_drain_vq(sc, 1); 951 952 if (virtio_reinit(dev, sc->vtblk_features) != 0) 953 panic("cannot reinit VirtIO block device during dump"); 954 955 virtqueue_disable_intr(vq); 956 virtio_reinit_complete(dev); 957 } 958 959 static int 960 vtblk_write_dump(struct vtblk_softc *sc, void *virtual, off_t offset, 961 size_t length) 962 { 963 struct bio buf; 964 struct vtblk_request *req; 965 966 req = &sc->vtblk_dump_request; 967 req->vbr_ack = -1; 968 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 969 req->vbr_hdr.ioprio = 1; 970 req->vbr_hdr.sector = offset / 512; 971 972 req->vbr_bp = &buf; 973 bzero(&buf, sizeof(struct bio)); 974 975 buf.bio_cmd = BIO_WRITE; 976 buf.bio_data = virtual; 977 buf.bio_bcount = length; 978 979 return (vtblk_poll_request(sc, req)); 980 } 981 982 static int 983 vtblk_flush_dump(struct vtblk_softc *sc) 984 { 985 struct bio buf; 986 struct vtblk_request *req; 987 988 req = &sc->vtblk_dump_request; 989 req->vbr_ack = -1; 990 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 991 req->vbr_hdr.ioprio = 1; 992 req->vbr_hdr.sector = 0; 993 994 req->vbr_bp = &buf; 995 bzero(&buf, sizeof(struct bio)); 996 997 buf.bio_cmd = BIO_FLUSH; 998 999 return (vtblk_poll_request(sc, req)); 1000 } 1001 1002 static int 1003 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1004 { 1005 struct virtqueue *vq; 1006 struct vtblk_request *r; 1007 int error; 1008 1009 vq = sc->vtblk_vq; 1010 1011 if (!virtqueue_empty(vq)) 1012 return (EBUSY); 1013 1014 error = vtblk_execute_request(sc, req); 1015 if (error) 1016 return (error); 1017 1018 virtqueue_notify(vq); 1019 1020 r = virtqueue_poll(vq, NULL); 1021 KASSERT(r == req, ("unexpected request response: %p/%p", r, req)); 1022 1023 error = vtblk_request_error(req); 1024 if (error && bootverbose) { 1025 device_printf(sc->vtblk_dev, 1026 "%s: IO error: %d\n", __FUNCTION__, error); 1027 } 1028 1029 return (error); 1030 } 1031 1032 static void 1033 vtblk_finish_completed(struct vtblk_softc *sc) 1034 { 1035 struct vtblk_request *req; 1036 struct bio *bp; 1037 int error; 1038 1039 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1040 bp = req->vbr_bp; 1041 1042 if (sc->vtblk_req_ordered != NULL) { 1043 /* This should be the only outstanding request. */ 1044 MPASS(sc->vtblk_req_ordered == req); 1045 sc->vtblk_req_ordered = NULL; 1046 } 1047 1048 error = vtblk_request_error(req); 1049 if (error) 1050 disk_err(bp, "hard error", -1, 1); 1051 1052 vtblk_finish_bio(bp, error); 1053 vtblk_enqueue_request(sc, req); 1054 } 1055 } 1056 1057 static void 1058 vtblk_drain_vq(struct vtblk_softc *sc, int skip_done) 1059 { 1060 struct virtqueue *vq; 1061 struct vtblk_request *req; 1062 int last; 1063 1064 vq = sc->vtblk_vq; 1065 last = 0; 1066 1067 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1068 if (!skip_done) 1069 vtblk_finish_bio(req->vbr_bp, ENXIO); 1070 1071 vtblk_enqueue_request(sc, req); 1072 } 1073 1074 sc->vtblk_req_ordered = NULL; 1075 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1076 } 1077 1078 static void 1079 vtblk_drain(struct vtblk_softc *sc) 1080 { 1081 struct bio_queue_head *bioq; 1082 struct vtblk_request *req; 1083 struct bio *bp; 1084 1085 bioq = &sc->vtblk_bioq; 1086 1087 if (sc->vtblk_vq != NULL) { 1088 vtblk_finish_completed(sc); 1089 vtblk_drain_vq(sc, 0); 1090 } 1091 1092 while ((req = vtblk_dequeue_ready(sc)) != NULL) { 1093 vtblk_finish_bio(req->vbr_bp, ENXIO); 1094 vtblk_enqueue_request(sc, req); 1095 } 1096 1097 while (bioq_first(bioq) != NULL) { 1098 bp = bioq_takefirst(bioq); 1099 vtblk_finish_bio(bp, ENXIO); 1100 } 1101 1102 vtblk_free_requests(sc); 1103 } 1104 1105 #ifdef INVARIANTS 1106 static void 1107 vtblk_request_invariants(struct vtblk_request *req) 1108 { 1109 int hdr_nsegs, ack_nsegs; 1110 1111 hdr_nsegs = sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)); 1112 ack_nsegs = sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)); 1113 1114 KASSERT(hdr_nsegs == 1, ("request header crossed page boundary")); 1115 KASSERT(ack_nsegs == 1, ("request ack crossed page boundary")); 1116 } 1117 #endif 1118 1119 static int 1120 vtblk_alloc_requests(struct vtblk_softc *sc) 1121 { 1122 struct vtblk_request *req; 1123 int i, nreqs; 1124 1125 nreqs = virtqueue_size(sc->vtblk_vq); 1126 1127 /* 1128 * Preallocate sufficient requests to keep the virtqueue full. Each 1129 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 1130 * the number allocated when indirect descriptors are not available. 1131 */ 1132 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 1133 nreqs /= VTBLK_MIN_SEGMENTS; 1134 1135 for (i = 0; i < nreqs; i++) { 1136 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 1137 if (req == NULL) 1138 return (ENOMEM); 1139 1140 #ifdef INVARIANTS 1141 vtblk_request_invariants(req); 1142 #endif 1143 1144 sc->vtblk_request_count++; 1145 vtblk_enqueue_request(sc, req); 1146 } 1147 1148 return (0); 1149 } 1150 1151 static void 1152 vtblk_free_requests(struct vtblk_softc *sc) 1153 { 1154 struct vtblk_request *req; 1155 1156 KASSERT(TAILQ_EMPTY(&sc->vtblk_req_ready), 1157 ("ready requests left on queue")); 1158 1159 while ((req = vtblk_dequeue_request(sc)) != NULL) { 1160 sc->vtblk_request_count--; 1161 free(req, M_DEVBUF); 1162 } 1163 1164 KASSERT(sc->vtblk_request_count == 0, 1165 ("leaked requests: %d", sc->vtblk_request_count)); 1166 } 1167 1168 static struct vtblk_request * 1169 vtblk_dequeue_request(struct vtblk_softc *sc) 1170 { 1171 struct vtblk_request *req; 1172 1173 req = TAILQ_FIRST(&sc->vtblk_req_free); 1174 if (req != NULL) 1175 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 1176 1177 return (req); 1178 } 1179 1180 static void 1181 vtblk_enqueue_request(struct vtblk_softc *sc, struct vtblk_request *req) 1182 { 1183 1184 bzero(req, sizeof(struct vtblk_request)); 1185 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 1186 } 1187 1188 static struct vtblk_request * 1189 vtblk_dequeue_ready(struct vtblk_softc *sc) 1190 { 1191 struct vtblk_request *req; 1192 1193 req = TAILQ_FIRST(&sc->vtblk_req_ready); 1194 if (req != NULL) 1195 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 1196 1197 return (req); 1198 } 1199 1200 static void 1201 vtblk_enqueue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 1202 { 1203 1204 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 1205 } 1206 1207 static int 1208 vtblk_request_error(struct vtblk_request *req) 1209 { 1210 int error; 1211 1212 switch (req->vbr_ack) { 1213 case VIRTIO_BLK_S_OK: 1214 error = 0; 1215 break; 1216 case VIRTIO_BLK_S_UNSUPP: 1217 error = ENOTSUP; 1218 break; 1219 default: 1220 error = EIO; 1221 break; 1222 } 1223 1224 return (error); 1225 } 1226 1227 static void 1228 vtblk_finish_bio(struct bio *bp, int error) 1229 { 1230 1231 if (error) { 1232 bp->bio_resid = bp->bio_bcount; 1233 bp->bio_error = error; 1234 bp->bio_flags |= BIO_ERROR; 1235 } 1236 1237 biodone(bp); 1238 } 1239