1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* Driver for VirtIO block devices. */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/bio.h> 38 #include <sys/malloc.h> 39 #include <sys/module.h> 40 #include <sys/msan.h> 41 #include <sys/sglist.h> 42 #include <sys/sysctl.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/queue.h> 46 47 #include <geom/geom.h> 48 #include <geom/geom_disk.h> 49 50 #include <machine/bus.h> 51 #include <machine/resource.h> 52 #include <sys/bus.h> 53 #include <sys/rman.h> 54 55 #include <dev/virtio/virtio.h> 56 #include <dev/virtio/virtqueue.h> 57 #include <dev/virtio/block/virtio_blk.h> 58 59 #include "virtio_if.h" 60 61 struct vtblk_request { 62 struct vtblk_softc *vbr_sc; 63 bus_dmamap_t vbr_mapp; 64 65 /* Fields after this point are zeroed for each request. */ 66 struct virtio_blk_outhdr vbr_hdr; 67 struct bio *vbr_bp; 68 uint8_t vbr_ack; 69 uint8_t vbr_requeue_on_error; 70 uint8_t vbr_busdma_wait; 71 int vbr_error; 72 TAILQ_ENTRY(vtblk_request) vbr_link; 73 }; 74 75 enum vtblk_cache_mode { 76 VTBLK_CACHE_WRITETHROUGH, 77 VTBLK_CACHE_WRITEBACK, 78 VTBLK_CACHE_MAX 79 }; 80 81 struct vtblk_softc { 82 device_t vtblk_dev; 83 struct mtx vtblk_mtx; 84 uint64_t vtblk_features; 85 uint32_t vtblk_flags; 86 #define VTBLK_FLAG_INDIRECT 0x0001 87 #define VTBLK_FLAG_DETACH 0x0002 88 #define VTBLK_FLAG_SUSPEND 0x0004 89 #define VTBLK_FLAG_BARRIER 0x0008 90 #define VTBLK_FLAG_WCE_CONFIG 0x0010 91 #define VTBLK_FLAG_BUSDMA_WAIT 0x0020 92 #define VTBLK_FLAG_BUSDMA_ALIGN 0x0040 93 94 struct virtqueue *vtblk_vq; 95 struct sglist *vtblk_sglist; 96 bus_dma_tag_t vtblk_dmat; 97 struct disk *vtblk_disk; 98 99 struct bio_queue_head vtblk_bioq; 100 TAILQ_HEAD(, vtblk_request) 101 vtblk_req_free; 102 TAILQ_HEAD(, vtblk_request) 103 vtblk_req_ready; 104 struct vtblk_request *vtblk_req_ordered; 105 106 int vtblk_max_nsegs; 107 int vtblk_request_count; 108 enum vtblk_cache_mode vtblk_write_cache; 109 110 struct bio_queue vtblk_dump_queue; 111 struct vtblk_request vtblk_dump_request; 112 }; 113 114 static struct virtio_feature_desc vtblk_feature_desc[] = { 115 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 116 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 117 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 118 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 119 { VIRTIO_BLK_F_RO, "ReadOnly" }, 120 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 121 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 122 { VIRTIO_BLK_F_FLUSH, "FlushCmd" }, 123 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 124 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, 125 { VIRTIO_BLK_F_MQ, "Multiqueue" }, 126 { VIRTIO_BLK_F_DISCARD, "Discard" }, 127 { VIRTIO_BLK_F_WRITE_ZEROES, "WriteZeros" }, 128 129 { 0, NULL } 130 }; 131 132 static int vtblk_modevent(module_t, int, void *); 133 134 static int vtblk_probe(device_t); 135 static int vtblk_attach(device_t); 136 static int vtblk_detach(device_t); 137 static int vtblk_suspend(device_t); 138 static int vtblk_resume(device_t); 139 static int vtblk_shutdown(device_t); 140 static int vtblk_attach_completed(device_t); 141 static int vtblk_config_change(device_t); 142 143 static int vtblk_open(struct disk *); 144 static int vtblk_close(struct disk *); 145 static int vtblk_ioctl(struct disk *, u_long, void *, int, 146 struct thread *); 147 static int vtblk_dump(void *, void *, off_t, size_t); 148 static void vtblk_strategy(struct bio *); 149 150 static int vtblk_negotiate_features(struct vtblk_softc *); 151 static int vtblk_setup_features(struct vtblk_softc *); 152 static int vtblk_maximum_segments(struct vtblk_softc *, 153 struct virtio_blk_config *); 154 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 155 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 156 static void vtblk_alloc_disk(struct vtblk_softc *, 157 struct virtio_blk_config *); 158 static void vtblk_create_disk(struct vtblk_softc *); 159 160 static int vtblk_request_prealloc(struct vtblk_softc *); 161 static void vtblk_request_free(struct vtblk_softc *); 162 static struct vtblk_request * 163 vtblk_request_dequeue(struct vtblk_softc *); 164 static void vtblk_request_enqueue(struct vtblk_softc *, 165 struct vtblk_request *); 166 static struct vtblk_request * 167 vtblk_request_next_ready(struct vtblk_softc *); 168 static void vtblk_request_requeue_ready(struct vtblk_softc *, 169 struct vtblk_request *); 170 static struct vtblk_request * 171 vtblk_request_next(struct vtblk_softc *); 172 static struct vtblk_request * 173 vtblk_request_bio(struct vtblk_softc *); 174 static int vtblk_request_execute(struct vtblk_request *, int); 175 static void vtblk_request_execute_cb(void *, 176 bus_dma_segment_t *, int, int); 177 static int vtblk_request_error(struct vtblk_request *); 178 179 static void vtblk_queue_completed(struct vtblk_softc *, 180 struct bio_queue *); 181 static void vtblk_done_completed(struct vtblk_softc *, 182 struct bio_queue *); 183 static void vtblk_drain_vq(struct vtblk_softc *); 184 static void vtblk_drain(struct vtblk_softc *); 185 186 static void vtblk_startio(struct vtblk_softc *); 187 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 188 189 static void vtblk_read_config(struct vtblk_softc *, 190 struct virtio_blk_config *); 191 static void vtblk_ident(struct vtblk_softc *); 192 static int vtblk_poll_request(struct vtblk_softc *, 193 struct vtblk_request *); 194 static int vtblk_quiesce(struct vtblk_softc *); 195 static void vtblk_vq_intr(void *); 196 static void vtblk_stop(struct vtblk_softc *); 197 198 static void vtblk_dump_quiesce(struct vtblk_softc *); 199 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 200 static int vtblk_dump_flush(struct vtblk_softc *); 201 static void vtblk_dump_complete(struct vtblk_softc *); 202 203 static void vtblk_set_write_cache(struct vtblk_softc *, int); 204 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 205 struct virtio_blk_config *); 206 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 207 208 static void vtblk_setup_sysctl(struct vtblk_softc *); 209 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 210 211 #define vtblk_modern(_sc) (((_sc)->vtblk_features & VIRTIO_F_VERSION_1) != 0) 212 #define vtblk_htog16(_sc, _val) virtio_htog16(vtblk_modern(_sc), _val) 213 #define vtblk_htog32(_sc, _val) virtio_htog32(vtblk_modern(_sc), _val) 214 #define vtblk_htog64(_sc, _val) virtio_htog64(vtblk_modern(_sc), _val) 215 #define vtblk_gtoh16(_sc, _val) virtio_gtoh16(vtblk_modern(_sc), _val) 216 #define vtblk_gtoh32(_sc, _val) virtio_gtoh32(vtblk_modern(_sc), _val) 217 #define vtblk_gtoh64(_sc, _val) virtio_gtoh64(vtblk_modern(_sc), _val) 218 219 /* Tunables. */ 220 static int vtblk_no_ident = 0; 221 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 222 static int vtblk_writecache_mode = -1; 223 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 224 225 #define VTBLK_COMMON_FEATURES \ 226 (VIRTIO_BLK_F_SIZE_MAX | \ 227 VIRTIO_BLK_F_SEG_MAX | \ 228 VIRTIO_BLK_F_GEOMETRY | \ 229 VIRTIO_BLK_F_RO | \ 230 VIRTIO_BLK_F_BLK_SIZE | \ 231 VIRTIO_BLK_F_FLUSH | \ 232 VIRTIO_BLK_F_TOPOLOGY | \ 233 VIRTIO_BLK_F_CONFIG_WCE | \ 234 VIRTIO_BLK_F_DISCARD | \ 235 VIRTIO_RING_F_INDIRECT_DESC) 236 237 #define VTBLK_MODERN_FEATURES (VTBLK_COMMON_FEATURES) 238 #define VTBLK_LEGACY_FEATURES (VIRTIO_BLK_F_BARRIER | VTBLK_COMMON_FEATURES) 239 240 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 241 #define VTBLK_LOCK_INIT(_sc, _name) \ 242 mtx_init(VTBLK_MTX((_sc)), (_name), \ 243 "VirtIO Block Lock", MTX_DEF) 244 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 245 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 246 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 247 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 248 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 249 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 250 251 #define VTBLK_DISK_NAME "vtbd" 252 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 253 #define VTBLK_BSIZE 512 254 255 /* 256 * Each block request uses at least two segments - one for the header 257 * and one for the status. 258 */ 259 #define VTBLK_MIN_SEGMENTS 2 260 261 static device_method_t vtblk_methods[] = { 262 /* Device methods. */ 263 DEVMETHOD(device_probe, vtblk_probe), 264 DEVMETHOD(device_attach, vtblk_attach), 265 DEVMETHOD(device_detach, vtblk_detach), 266 DEVMETHOD(device_suspend, vtblk_suspend), 267 DEVMETHOD(device_resume, vtblk_resume), 268 DEVMETHOD(device_shutdown, vtblk_shutdown), 269 270 /* VirtIO methods. */ 271 DEVMETHOD(virtio_attach_completed, vtblk_attach_completed), 272 DEVMETHOD(virtio_config_change, vtblk_config_change), 273 274 DEVMETHOD_END 275 }; 276 277 static driver_t vtblk_driver = { 278 "vtblk", 279 vtblk_methods, 280 sizeof(struct vtblk_softc) 281 }; 282 283 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_modevent, NULL); 284 MODULE_VERSION(virtio_blk, 1); 285 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 286 287 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter"); 288 289 static int 290 vtblk_modevent(module_t mod, int type, void *unused) 291 { 292 int error; 293 294 error = 0; 295 296 switch (type) { 297 case MOD_LOAD: 298 case MOD_QUIESCE: 299 case MOD_UNLOAD: 300 case MOD_SHUTDOWN: 301 break; 302 default: 303 error = EOPNOTSUPP; 304 break; 305 } 306 307 return (error); 308 } 309 310 static int 311 vtblk_probe(device_t dev) 312 { 313 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk)); 314 } 315 316 static int 317 vtblk_attach(device_t dev) 318 { 319 struct vtblk_softc *sc; 320 struct virtio_blk_config blkcfg; 321 int error; 322 323 sc = device_get_softc(dev); 324 sc->vtblk_dev = dev; 325 virtio_set_feature_desc(dev, vtblk_feature_desc); 326 327 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 328 bioq_init(&sc->vtblk_bioq); 329 TAILQ_INIT(&sc->vtblk_dump_queue); 330 TAILQ_INIT(&sc->vtblk_req_free); 331 TAILQ_INIT(&sc->vtblk_req_ready); 332 333 vtblk_setup_sysctl(sc); 334 335 error = vtblk_setup_features(sc); 336 if (error) { 337 device_printf(dev, "cannot setup features\n"); 338 goto fail; 339 } 340 341 vtblk_read_config(sc, &blkcfg); 342 343 /* 344 * With the current sglist(9) implementation, it is not easy 345 * for us to support a maximum segment size as adjacent 346 * segments are coalesced. For now, just make sure it's larger 347 * than the maximum supported transfer size. 348 */ 349 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 350 if (blkcfg.size_max < maxphys) { 351 error = ENOTSUP; 352 device_printf(dev, "host requires unsupported " 353 "maximum segment size feature\n"); 354 goto fail; 355 } 356 } 357 358 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 359 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 360 error = EINVAL; 361 device_printf(dev, "fewer than minimum number of segments " 362 "allowed: %d\n", sc->vtblk_max_nsegs); 363 goto fail; 364 } 365 366 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 367 if (sc->vtblk_sglist == NULL) { 368 error = ENOMEM; 369 device_printf(dev, "cannot allocate sglist\n"); 370 goto fail; 371 } 372 373 /* 374 * If vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1, the device only 375 * supports a single data segment; in that case we need busdma to 376 * align to a page boundary so we can send a *contiguous* page size 377 * request to the host. 378 */ 379 if (sc->vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1) 380 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_ALIGN; 381 error = bus_dma_tag_create( 382 bus_get_dma_tag(dev), /* parent */ 383 (sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) ? PAGE_SIZE : 1, 384 0, /* boundary */ 385 BUS_SPACE_MAXADDR, /* lowaddr */ 386 BUS_SPACE_MAXADDR, /* highaddr */ 387 NULL, NULL, /* filter, filterarg */ 388 maxphys, /* max request size */ 389 sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS, /* max # segments */ 390 maxphys, /* maxsegsize */ 391 0, /* flags */ 392 busdma_lock_mutex, /* lockfunc */ 393 &sc->vtblk_mtx, /* lockarg */ 394 &sc->vtblk_dmat); 395 if (error) { 396 device_printf(dev, "cannot create bus dma tag\n"); 397 goto fail; 398 } 399 400 error = vtblk_alloc_virtqueue(sc); 401 if (error) { 402 device_printf(dev, "cannot allocate virtqueue\n"); 403 goto fail; 404 } 405 406 error = vtblk_request_prealloc(sc); 407 if (error) { 408 device_printf(dev, "cannot preallocate requests\n"); 409 goto fail; 410 } 411 412 vtblk_alloc_disk(sc, &blkcfg); 413 414 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 415 if (error) { 416 device_printf(dev, "cannot setup virtqueue interrupt\n"); 417 goto fail; 418 } 419 420 virtqueue_enable_intr(sc->vtblk_vq); 421 422 fail: 423 if (error) 424 vtblk_detach(dev); 425 426 return (error); 427 } 428 429 static int 430 vtblk_detach(device_t dev) 431 { 432 struct vtblk_softc *sc; 433 434 sc = device_get_softc(dev); 435 436 VTBLK_LOCK(sc); 437 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 438 if (device_is_attached(dev)) 439 vtblk_stop(sc); 440 VTBLK_UNLOCK(sc); 441 442 vtblk_drain(sc); 443 444 if (sc->vtblk_disk != NULL) { 445 disk_destroy(sc->vtblk_disk); 446 sc->vtblk_disk = NULL; 447 } 448 449 if (sc->vtblk_dmat != NULL) { 450 bus_dma_tag_destroy(sc->vtblk_dmat); 451 sc->vtblk_dmat = NULL; 452 } 453 454 if (sc->vtblk_sglist != NULL) { 455 sglist_free(sc->vtblk_sglist); 456 sc->vtblk_sglist = NULL; 457 } 458 459 VTBLK_LOCK_DESTROY(sc); 460 461 return (0); 462 } 463 464 static int 465 vtblk_suspend(device_t dev) 466 { 467 struct vtblk_softc *sc; 468 int error; 469 470 sc = device_get_softc(dev); 471 472 VTBLK_LOCK(sc); 473 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 474 /* XXX BMV: virtio_stop(), etc needed here? */ 475 error = vtblk_quiesce(sc); 476 if (error) 477 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 478 VTBLK_UNLOCK(sc); 479 480 return (error); 481 } 482 483 static int 484 vtblk_resume(device_t dev) 485 { 486 struct vtblk_softc *sc; 487 488 sc = device_get_softc(dev); 489 490 VTBLK_LOCK(sc); 491 /* XXX BMV: virtio_reinit(), etc needed here? */ 492 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 493 vtblk_startio(sc); 494 VTBLK_UNLOCK(sc); 495 496 return (0); 497 } 498 499 static int 500 vtblk_shutdown(device_t dev) 501 { 502 503 return (0); 504 } 505 506 static int 507 vtblk_attach_completed(device_t dev) 508 { 509 struct vtblk_softc *sc; 510 511 sc = device_get_softc(dev); 512 513 /* 514 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be 515 * processed after the device acknowledged 516 * VIRTIO_CONFIG_STATUS_DRIVER_OK. 517 */ 518 vtblk_create_disk(sc); 519 return (0); 520 } 521 522 static int 523 vtblk_config_change(device_t dev) 524 { 525 struct vtblk_softc *sc; 526 struct virtio_blk_config blkcfg; 527 uint64_t capacity; 528 529 sc = device_get_softc(dev); 530 531 vtblk_read_config(sc, &blkcfg); 532 533 /* Capacity is always in 512-byte units. */ 534 capacity = blkcfg.capacity * VTBLK_BSIZE; 535 536 if (sc->vtblk_disk->d_mediasize != capacity) 537 vtblk_resize_disk(sc, capacity); 538 539 return (0); 540 } 541 542 static int 543 vtblk_open(struct disk *dp) 544 { 545 struct vtblk_softc *sc; 546 547 if ((sc = dp->d_drv1) == NULL) 548 return (ENXIO); 549 550 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 551 } 552 553 static int 554 vtblk_close(struct disk *dp) 555 { 556 struct vtblk_softc *sc; 557 558 if ((sc = dp->d_drv1) == NULL) 559 return (ENXIO); 560 561 return (0); 562 } 563 564 static int 565 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 566 struct thread *td) 567 { 568 struct vtblk_softc *sc; 569 570 if ((sc = dp->d_drv1) == NULL) 571 return (ENXIO); 572 573 return (ENOTTY); 574 } 575 576 static int 577 vtblk_dump(void *arg, void *virtual, off_t offset, size_t length) 578 { 579 struct disk *dp; 580 struct vtblk_softc *sc; 581 int error; 582 583 dp = arg; 584 error = 0; 585 586 if ((sc = dp->d_drv1) == NULL) 587 return (ENXIO); 588 589 VTBLK_LOCK(sc); 590 591 vtblk_dump_quiesce(sc); 592 593 if (length > 0) 594 error = vtblk_dump_write(sc, virtual, offset, length); 595 if (error || (virtual == NULL && offset == 0)) 596 vtblk_dump_complete(sc); 597 598 VTBLK_UNLOCK(sc); 599 600 return (error); 601 } 602 603 static void 604 vtblk_strategy(struct bio *bp) 605 { 606 struct vtblk_softc *sc; 607 608 if ((sc = bp->bio_disk->d_drv1) == NULL) { 609 vtblk_bio_done(NULL, bp, EINVAL); 610 return; 611 } 612 613 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) && 614 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) { 615 vtblk_bio_done(sc, bp, EOPNOTSUPP); 616 return; 617 } 618 619 VTBLK_LOCK(sc); 620 621 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 622 VTBLK_UNLOCK(sc); 623 vtblk_bio_done(sc, bp, ENXIO); 624 return; 625 } 626 627 bioq_insert_tail(&sc->vtblk_bioq, bp); 628 vtblk_startio(sc); 629 630 VTBLK_UNLOCK(sc); 631 } 632 633 static int 634 vtblk_negotiate_features(struct vtblk_softc *sc) 635 { 636 device_t dev; 637 uint64_t features; 638 639 dev = sc->vtblk_dev; 640 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES : 641 VTBLK_LEGACY_FEATURES; 642 643 sc->vtblk_features = virtio_negotiate_features(dev, features); 644 return (virtio_finalize_features(dev)); 645 } 646 647 static int 648 vtblk_setup_features(struct vtblk_softc *sc) 649 { 650 device_t dev; 651 int error; 652 653 dev = sc->vtblk_dev; 654 655 error = vtblk_negotiate_features(sc); 656 if (error) 657 return (error); 658 659 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 660 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 661 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 662 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG; 663 664 /* Legacy. */ 665 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 666 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 667 668 return (0); 669 } 670 671 static int 672 vtblk_maximum_segments(struct vtblk_softc *sc, 673 struct virtio_blk_config *blkcfg) 674 { 675 device_t dev; 676 int nsegs; 677 678 dev = sc->vtblk_dev; 679 nsegs = VTBLK_MIN_SEGMENTS; 680 681 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 682 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1); 683 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 684 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 685 } else 686 nsegs += 1; 687 688 return (nsegs); 689 } 690 691 static int 692 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 693 { 694 device_t dev; 695 struct vq_alloc_info vq_info; 696 697 dev = sc->vtblk_dev; 698 699 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 700 vtblk_vq_intr, sc, &sc->vtblk_vq, 701 "%s request", device_get_nameunit(dev)); 702 703 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 704 } 705 706 static void 707 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 708 { 709 device_t dev; 710 struct disk *dp; 711 int error; 712 713 dev = sc->vtblk_dev; 714 dp = sc->vtblk_disk; 715 716 dp->d_mediasize = new_capacity; 717 if (bootverbose) { 718 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 719 (uintmax_t) dp->d_mediasize >> 20, 720 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 721 dp->d_sectorsize); 722 } 723 724 error = disk_resize(dp, M_NOWAIT); 725 if (error) { 726 device_printf(dev, 727 "disk_resize(9) failed, error: %d\n", error); 728 } 729 } 730 731 static void 732 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 733 { 734 device_t dev; 735 struct disk *dp; 736 737 dev = sc->vtblk_dev; 738 739 sc->vtblk_disk = dp = disk_alloc(); 740 dp->d_open = vtblk_open; 741 dp->d_close = vtblk_close; 742 dp->d_ioctl = vtblk_ioctl; 743 dp->d_strategy = vtblk_strategy; 744 dp->d_name = VTBLK_DISK_NAME; 745 dp->d_unit = device_get_unit(dev); 746 dp->d_drv1 = sc; 747 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION; 748 dp->d_hba_vendor = virtio_get_vendor(dev); 749 dp->d_hba_device = virtio_get_device(dev); 750 dp->d_hba_subvendor = virtio_get_subvendor(dev); 751 dp->d_hba_subdevice = virtio_get_subdevice(dev); 752 753 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 754 dp->d_flags |= DISKFLAG_WRITE_PROTECT; 755 else { 756 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 757 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 758 dp->d_dump = vtblk_dump; 759 } 760 761 /* Capacity is always in 512-byte units. */ 762 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE; 763 764 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 765 dp->d_sectorsize = blkcfg->blk_size; 766 else 767 dp->d_sectorsize = VTBLK_BSIZE; 768 769 /* 770 * The VirtIO maximum I/O size is given in terms of segments. 771 * However, FreeBSD limits I/O size by logical buffer size, not 772 * by physically contiguous pages. Therefore, we have to assume 773 * no pages are contiguous. This may impose an artificially low 774 * maximum I/O size. But in practice, since QEMU advertises 128 775 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 776 * which is typically greater than maxphys. Eventually we should 777 * just advertise maxphys and split buffers that are too big. 778 * 779 * If we're not asking busdma to align data to page boundaries, the 780 * maximum I/O size is reduced by PAGE_SIZE in order to accommodate 781 * unaligned I/Os. 782 */ 783 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS) * 784 PAGE_SIZE; 785 if ((sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) == 0) 786 dp->d_maxsize -= PAGE_SIZE; 787 788 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 789 dp->d_fwsectors = blkcfg->geometry.sectors; 790 dp->d_fwheads = blkcfg->geometry.heads; 791 } 792 793 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 794 blkcfg->topology.physical_block_exp > 0) { 795 dp->d_stripesize = dp->d_sectorsize * 796 (1 << blkcfg->topology.physical_block_exp); 797 dp->d_stripeoffset = (dp->d_stripesize - 798 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 799 dp->d_stripesize; 800 } 801 802 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) { 803 dp->d_flags |= DISKFLAG_CANDELETE; 804 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE; 805 } 806 807 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 808 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 809 else 810 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 811 } 812 813 static void 814 vtblk_create_disk(struct vtblk_softc *sc) 815 { 816 struct disk *dp; 817 818 dp = sc->vtblk_disk; 819 820 vtblk_ident(sc); 821 822 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 823 (uintmax_t) dp->d_mediasize >> 20, 824 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 825 dp->d_sectorsize); 826 827 disk_create(dp, DISK_VERSION); 828 } 829 830 static int 831 vtblk_request_prealloc(struct vtblk_softc *sc) 832 { 833 struct vtblk_request *req; 834 int i, nreqs; 835 836 nreqs = virtqueue_size(sc->vtblk_vq); 837 838 /* 839 * Preallocate sufficient requests to keep the virtqueue full. Each 840 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 841 * the number allocated when indirect descriptors are not available. 842 */ 843 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 844 nreqs /= VTBLK_MIN_SEGMENTS; 845 846 for (i = 0; i < nreqs; i++) { 847 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 848 if (req == NULL) 849 return (ENOMEM); 850 851 req->vbr_sc = sc; 852 if (bus_dmamap_create(sc->vtblk_dmat, 0, &req->vbr_mapp)) { 853 free(req, M_DEVBUF); 854 return (ENOMEM); 855 } 856 857 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 858 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 859 860 sc->vtblk_request_count++; 861 vtblk_request_enqueue(sc, req); 862 } 863 864 return (0); 865 } 866 867 static void 868 vtblk_request_free(struct vtblk_softc *sc) 869 { 870 struct vtblk_request *req; 871 872 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 873 874 while ((req = vtblk_request_dequeue(sc)) != NULL) { 875 sc->vtblk_request_count--; 876 bus_dmamap_destroy(sc->vtblk_dmat, req->vbr_mapp); 877 free(req, M_DEVBUF); 878 } 879 880 KASSERT(sc->vtblk_request_count == 0, 881 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 882 } 883 884 static struct vtblk_request * 885 vtblk_request_dequeue(struct vtblk_softc *sc) 886 { 887 struct vtblk_request *req; 888 889 req = TAILQ_FIRST(&sc->vtblk_req_free); 890 if (req != NULL) { 891 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 892 bzero(&req->vbr_hdr, sizeof(struct vtblk_request) - 893 offsetof(struct vtblk_request, vbr_hdr)); 894 } 895 896 return (req); 897 } 898 899 static void 900 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 901 { 902 903 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 904 } 905 906 static struct vtblk_request * 907 vtblk_request_next_ready(struct vtblk_softc *sc) 908 { 909 struct vtblk_request *req; 910 911 req = TAILQ_FIRST(&sc->vtblk_req_ready); 912 if (req != NULL) 913 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 914 915 return (req); 916 } 917 918 static void 919 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 920 { 921 922 /* NOTE: Currently, there will be at most one request in the queue. */ 923 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 924 } 925 926 static struct vtblk_request * 927 vtblk_request_next(struct vtblk_softc *sc) 928 { 929 struct vtblk_request *req; 930 931 req = vtblk_request_next_ready(sc); 932 if (req != NULL) 933 return (req); 934 935 return (vtblk_request_bio(sc)); 936 } 937 938 static struct vtblk_request * 939 vtblk_request_bio(struct vtblk_softc *sc) 940 { 941 struct bio_queue_head *bioq; 942 struct vtblk_request *req; 943 struct bio *bp; 944 945 bioq = &sc->vtblk_bioq; 946 947 if (bioq_first(bioq) == NULL) 948 return (NULL); 949 950 req = vtblk_request_dequeue(sc); 951 if (req == NULL) 952 return (NULL); 953 954 bp = bioq_takefirst(bioq); 955 req->vbr_bp = bp; 956 req->vbr_ack = -1; 957 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 958 959 switch (bp->bio_cmd) { 960 case BIO_FLUSH: 961 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 962 req->vbr_hdr.sector = 0; 963 break; 964 case BIO_READ: 965 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN); 966 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 967 break; 968 case BIO_WRITE: 969 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 970 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 971 break; 972 case BIO_DELETE: 973 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD); 974 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 975 break; 976 default: 977 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 978 } 979 980 if (bp->bio_flags & BIO_ORDERED) 981 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER); 982 983 return (req); 984 } 985 986 static int 987 vtblk_request_execute(struct vtblk_request *req, int flags) 988 { 989 struct vtblk_softc *sc = req->vbr_sc; 990 struct bio *bp = req->vbr_bp; 991 int error = 0; 992 993 /* 994 * Call via bus_dmamap_load_bio or directly depending on whether we 995 * have a buffer we need to map. 996 */ 997 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 998 error = bus_dmamap_load_bio(sc->vtblk_dmat, req->vbr_mapp, 999 req->vbr_bp, vtblk_request_execute_cb, req, flags); 1000 if (error == EINPROGRESS) { 1001 req->vbr_busdma_wait = 1; 1002 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_WAIT; 1003 } 1004 } else { 1005 vtblk_request_execute_cb(req, NULL, 0, 0); 1006 } 1007 1008 return (error ? error : req->vbr_error); 1009 } 1010 1011 static void 1012 vtblk_request_execute_cb(void * callback_arg, bus_dma_segment_t * segs, 1013 int nseg, int error) 1014 { 1015 struct vtblk_request *req; 1016 struct vtblk_softc *sc; 1017 struct virtqueue *vq; 1018 struct sglist *sg; 1019 struct bio *bp; 1020 int ordered, readable, writable, i; 1021 1022 req = (struct vtblk_request *)callback_arg; 1023 sc = req->vbr_sc; 1024 vq = sc->vtblk_vq; 1025 sg = sc->vtblk_sglist; 1026 bp = req->vbr_bp; 1027 ordered = 0; 1028 writable = 0; 1029 1030 /* 1031 * If we paused request queueing while we waited for busdma to call us 1032 * asynchronously, unpause it now; this request made it through so we 1033 * don't need to worry about others getting ahead of us. (Note that we 1034 * hold the device mutex so nothing will happen until after we return 1035 * anyway.) 1036 */ 1037 if (req->vbr_busdma_wait) 1038 sc->vtblk_flags &= ~VTBLK_FLAG_BUSDMA_WAIT; 1039 1040 /* Fail on errors from busdma. */ 1041 if (error) 1042 goto out1; 1043 1044 /* 1045 * Some hosts (such as bhyve) do not implement the barrier feature, 1046 * so we emulate it in the driver by allowing the barrier request 1047 * to be the only one in flight. 1048 */ 1049 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 1050 if (sc->vtblk_req_ordered != NULL) { 1051 error = EBUSY; 1052 goto out; 1053 } 1054 if (bp->bio_flags & BIO_ORDERED) { 1055 if (!virtqueue_empty(vq)) { 1056 error = EBUSY; 1057 goto out; 1058 } 1059 ordered = 1; 1060 req->vbr_hdr.type &= vtblk_gtoh32(sc, 1061 ~VIRTIO_BLK_T_BARRIER); 1062 } 1063 } 1064 1065 sglist_reset(sg); 1066 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 1067 1068 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 1069 /* 1070 * We cast bus_addr_t to vm_paddr_t here; this isn't valid on 1071 * all platforms, but we believe it works on all platforms 1072 * which are supported by virtio. 1073 */ 1074 for (i = 0; i < nseg; i++) { 1075 error = sglist_append_phys(sg, 1076 (vm_paddr_t)segs[i].ds_addr, segs[i].ds_len); 1077 if (error || sg->sg_nseg == sg->sg_maxseg) { 1078 panic("%s: bio %p data buffer too big %d", 1079 __func__, bp, error); 1080 } 1081 } 1082 1083 /* BIO_READ means the host writes into our buffer. */ 1084 if (bp->bio_cmd == BIO_READ) 1085 writable = sg->sg_nseg - 1; 1086 } else if (bp->bio_cmd == BIO_DELETE) { 1087 struct virtio_blk_discard_write_zeroes *discard; 1088 1089 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO); 1090 if (discard == NULL) { 1091 error = ENOMEM; 1092 goto out; 1093 } 1094 1095 bp->bio_driver1 = discard; 1096 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 1097 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE); 1098 error = sglist_append(sg, discard, sizeof(*discard)); 1099 if (error || sg->sg_nseg == sg->sg_maxseg) { 1100 panic("%s: bio %p data buffer too big %d", 1101 __func__, bp, error); 1102 } 1103 } 1104 1105 writable++; 1106 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 1107 readable = sg->sg_nseg - writable; 1108 1109 switch (bp->bio_cmd) { 1110 case BIO_READ: 1111 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1112 BUS_DMASYNC_PREREAD); 1113 break; 1114 case BIO_WRITE: 1115 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1116 BUS_DMASYNC_PREWRITE); 1117 break; 1118 } 1119 1120 error = virtqueue_enqueue(vq, req, sg, readable, writable); 1121 if (error == 0 && ordered) 1122 sc->vtblk_req_ordered = req; 1123 1124 /* 1125 * If we were called asynchronously, we need to notify the queue that 1126 * we've added a new request, since the notification from startio was 1127 * performed already. 1128 */ 1129 if (error == 0 && req->vbr_busdma_wait) 1130 virtqueue_notify(vq); 1131 1132 out: 1133 if (error) 1134 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp); 1135 out1: 1136 if (error && req->vbr_requeue_on_error) 1137 vtblk_request_requeue_ready(sc, req); 1138 req->vbr_error = error; 1139 } 1140 1141 static int 1142 vtblk_request_error(struct vtblk_request *req) 1143 { 1144 int error; 1145 1146 switch (req->vbr_ack) { 1147 case VIRTIO_BLK_S_OK: 1148 error = 0; 1149 break; 1150 case VIRTIO_BLK_S_UNSUPP: 1151 error = ENOTSUP; 1152 break; 1153 default: 1154 error = EIO; 1155 break; 1156 } 1157 1158 return (error); 1159 } 1160 1161 static void 1162 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1163 { 1164 struct vtblk_request *req; 1165 struct bio *bp; 1166 1167 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1168 if (sc->vtblk_req_ordered != NULL) { 1169 MPASS(sc->vtblk_req_ordered == req); 1170 sc->vtblk_req_ordered = NULL; 1171 } 1172 1173 bp = req->vbr_bp; 1174 switch (bp->bio_cmd) { 1175 case BIO_READ: 1176 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1177 BUS_DMASYNC_POSTREAD); 1178 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp); 1179 break; 1180 case BIO_WRITE: 1181 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1182 BUS_DMASYNC_POSTWRITE); 1183 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp); 1184 break; 1185 } 1186 bp->bio_error = vtblk_request_error(req); 1187 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 1188 1189 vtblk_request_enqueue(sc, req); 1190 } 1191 } 1192 1193 static void 1194 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1195 { 1196 struct bio *bp, *tmp; 1197 1198 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 1199 if (bp->bio_error != 0) 1200 disk_err(bp, "hard error", -1, 1); 1201 vtblk_bio_done(sc, bp, bp->bio_error); 1202 } 1203 } 1204 1205 static void 1206 vtblk_drain_vq(struct vtblk_softc *sc) 1207 { 1208 struct virtqueue *vq; 1209 struct vtblk_request *req; 1210 int last; 1211 1212 vq = sc->vtblk_vq; 1213 last = 0; 1214 1215 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1216 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1217 vtblk_request_enqueue(sc, req); 1218 } 1219 1220 sc->vtblk_req_ordered = NULL; 1221 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1222 } 1223 1224 static void 1225 vtblk_drain(struct vtblk_softc *sc) 1226 { 1227 struct bio_queue_head *bioq; 1228 struct vtblk_request *req; 1229 struct bio *bp; 1230 1231 bioq = &sc->vtblk_bioq; 1232 1233 if (sc->vtblk_vq != NULL) { 1234 struct bio_queue queue; 1235 1236 TAILQ_INIT(&queue); 1237 vtblk_queue_completed(sc, &queue); 1238 vtblk_done_completed(sc, &queue); 1239 1240 vtblk_drain_vq(sc); 1241 } 1242 1243 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1244 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1245 vtblk_request_enqueue(sc, req); 1246 } 1247 1248 while (bioq_first(bioq) != NULL) { 1249 bp = bioq_takefirst(bioq); 1250 vtblk_bio_done(sc, bp, ENXIO); 1251 } 1252 1253 vtblk_request_free(sc); 1254 } 1255 1256 static void 1257 vtblk_startio(struct vtblk_softc *sc) 1258 { 1259 struct virtqueue *vq; 1260 struct vtblk_request *req; 1261 int enq; 1262 1263 VTBLK_LOCK_ASSERT(sc); 1264 vq = sc->vtblk_vq; 1265 enq = 0; 1266 1267 if (sc->vtblk_flags & (VTBLK_FLAG_SUSPEND | VTBLK_FLAG_BUSDMA_WAIT)) 1268 return; 1269 1270 while (!virtqueue_full(vq)) { 1271 req = vtblk_request_next(sc); 1272 if (req == NULL) 1273 break; 1274 1275 req->vbr_requeue_on_error = 1; 1276 if (vtblk_request_execute(req, BUS_DMA_WAITOK)) 1277 break; 1278 1279 enq++; 1280 } 1281 1282 if (enq > 0) 1283 virtqueue_notify(vq); 1284 } 1285 1286 static void 1287 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1288 { 1289 1290 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1291 if (sc != NULL) 1292 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1293 1294 if (error) { 1295 bp->bio_resid = bp->bio_bcount; 1296 bp->bio_error = error; 1297 bp->bio_flags |= BIO_ERROR; 1298 } else { 1299 kmsan_mark_bio(bp, KMSAN_STATE_INITED); 1300 } 1301 1302 if (bp->bio_driver1 != NULL) { 1303 free(bp->bio_driver1, M_DEVBUF); 1304 bp->bio_driver1 = NULL; 1305 } 1306 1307 biodone(bp); 1308 } 1309 1310 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1311 if (virtio_with_feature(_dev, _feature)) { \ 1312 virtio_read_device_config(_dev, \ 1313 offsetof(struct virtio_blk_config, _field), \ 1314 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1315 } 1316 1317 static void 1318 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1319 { 1320 device_t dev; 1321 1322 dev = sc->vtblk_dev; 1323 1324 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1325 1326 /* The capacity is always available. */ 1327 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1328 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1329 1330 /* Read the configuration if the feature was negotiated. */ 1331 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1332 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1333 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1334 geometry.cylinders, blkcfg); 1335 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1336 geometry.heads, blkcfg); 1337 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1338 geometry.sectors, blkcfg); 1339 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1340 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1341 topology.physical_block_exp, blkcfg); 1342 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1343 topology.alignment_offset, blkcfg); 1344 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1345 topology.min_io_size, blkcfg); 1346 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1347 topology.opt_io_size, blkcfg); 1348 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg); 1349 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors, 1350 blkcfg); 1351 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg); 1352 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment, 1353 blkcfg); 1354 } 1355 1356 #undef VTBLK_GET_CONFIG 1357 1358 static void 1359 vtblk_ident(struct vtblk_softc *sc) 1360 { 1361 struct bio buf; 1362 struct disk *dp; 1363 struct vtblk_request *req; 1364 int len, error; 1365 1366 dp = sc->vtblk_disk; 1367 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1368 1369 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1370 return; 1371 1372 req = vtblk_request_dequeue(sc); 1373 if (req == NULL) 1374 return; 1375 1376 req->vbr_ack = -1; 1377 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID); 1378 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1379 req->vbr_hdr.sector = 0; 1380 1381 req->vbr_bp = &buf; 1382 g_reset_bio(&buf); 1383 1384 buf.bio_cmd = BIO_READ; 1385 buf.bio_data = dp->d_ident; 1386 buf.bio_bcount = len; 1387 1388 VTBLK_LOCK(sc); 1389 error = vtblk_poll_request(sc, req); 1390 VTBLK_UNLOCK(sc); 1391 1392 vtblk_request_enqueue(sc, req); 1393 1394 if (error) { 1395 device_printf(sc->vtblk_dev, 1396 "error getting device identifier: %d\n", error); 1397 } 1398 } 1399 1400 static int 1401 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1402 { 1403 struct virtqueue *vq; 1404 int error; 1405 1406 vq = sc->vtblk_vq; 1407 1408 if (!virtqueue_empty(vq)) 1409 return (EBUSY); 1410 1411 error = vtblk_request_execute(req, BUS_DMA_NOWAIT); 1412 if (error) 1413 return (error); 1414 1415 virtqueue_notify(vq); 1416 virtqueue_poll(vq, NULL); 1417 1418 error = vtblk_request_error(req); 1419 if (error && bootverbose) { 1420 device_printf(sc->vtblk_dev, 1421 "%s: IO error: %d\n", __func__, error); 1422 } 1423 1424 return (error); 1425 } 1426 1427 static int 1428 vtblk_quiesce(struct vtblk_softc *sc) 1429 { 1430 int error; 1431 1432 VTBLK_LOCK_ASSERT(sc); 1433 error = 0; 1434 1435 while (!virtqueue_empty(sc->vtblk_vq)) { 1436 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1437 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1438 error = EBUSY; 1439 break; 1440 } 1441 } 1442 1443 return (error); 1444 } 1445 1446 static void 1447 vtblk_vq_intr(void *xsc) 1448 { 1449 struct vtblk_softc *sc; 1450 struct virtqueue *vq; 1451 struct bio_queue queue; 1452 1453 sc = xsc; 1454 vq = sc->vtblk_vq; 1455 TAILQ_INIT(&queue); 1456 1457 VTBLK_LOCK(sc); 1458 1459 again: 1460 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1461 goto out; 1462 1463 vtblk_queue_completed(sc, &queue); 1464 vtblk_startio(sc); 1465 1466 if (virtqueue_enable_intr(vq) != 0) { 1467 virtqueue_disable_intr(vq); 1468 goto again; 1469 } 1470 1471 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1472 wakeup(&sc->vtblk_vq); 1473 1474 out: 1475 VTBLK_UNLOCK(sc); 1476 vtblk_done_completed(sc, &queue); 1477 } 1478 1479 static void 1480 vtblk_stop(struct vtblk_softc *sc) 1481 { 1482 1483 virtqueue_disable_intr(sc->vtblk_vq); 1484 virtio_stop(sc->vtblk_dev); 1485 } 1486 1487 static void 1488 vtblk_dump_quiesce(struct vtblk_softc *sc) 1489 { 1490 1491 /* 1492 * Spin here until all the requests in-flight at the time of the 1493 * dump are completed and queued. The queued requests will be 1494 * biodone'd once the dump is finished. 1495 */ 1496 while (!virtqueue_empty(sc->vtblk_vq)) 1497 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1498 } 1499 1500 static int 1501 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1502 size_t length) 1503 { 1504 struct bio buf; 1505 struct vtblk_request *req; 1506 1507 req = &sc->vtblk_dump_request; 1508 req->vbr_ack = -1; 1509 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 1510 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1511 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE); 1512 1513 req->vbr_bp = &buf; 1514 g_reset_bio(&buf); 1515 1516 buf.bio_cmd = BIO_WRITE; 1517 buf.bio_data = virtual; 1518 buf.bio_bcount = length; 1519 1520 return (vtblk_poll_request(sc, req)); 1521 } 1522 1523 static int 1524 vtblk_dump_flush(struct vtblk_softc *sc) 1525 { 1526 struct bio buf; 1527 struct vtblk_request *req; 1528 1529 req = &sc->vtblk_dump_request; 1530 req->vbr_ack = -1; 1531 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 1532 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1533 req->vbr_hdr.sector = 0; 1534 1535 req->vbr_bp = &buf; 1536 g_reset_bio(&buf); 1537 1538 buf.bio_cmd = BIO_FLUSH; 1539 1540 return (vtblk_poll_request(sc, req)); 1541 } 1542 1543 static void 1544 vtblk_dump_complete(struct vtblk_softc *sc) 1545 { 1546 1547 vtblk_dump_flush(sc); 1548 1549 VTBLK_UNLOCK(sc); 1550 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1551 VTBLK_LOCK(sc); 1552 } 1553 1554 static void 1555 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1556 { 1557 1558 /* Set either writeback (1) or writethrough (0) mode. */ 1559 virtio_write_dev_config_1(sc->vtblk_dev, 1560 offsetof(struct virtio_blk_config, wce), wc); 1561 } 1562 1563 static int 1564 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1565 struct virtio_blk_config *blkcfg) 1566 { 1567 int wc; 1568 1569 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) { 1570 wc = vtblk_tunable_int(sc, "writecache_mode", 1571 vtblk_writecache_mode); 1572 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1573 vtblk_set_write_cache(sc, wc); 1574 else 1575 wc = blkcfg->wce; 1576 } else 1577 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH); 1578 1579 return (wc); 1580 } 1581 1582 static int 1583 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1584 { 1585 struct vtblk_softc *sc; 1586 int wc, error; 1587 1588 sc = oidp->oid_arg1; 1589 wc = sc->vtblk_write_cache; 1590 1591 error = sysctl_handle_int(oidp, &wc, 0, req); 1592 if (error || req->newptr == NULL) 1593 return (error); 1594 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0) 1595 return (EPERM); 1596 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1597 return (EINVAL); 1598 1599 VTBLK_LOCK(sc); 1600 sc->vtblk_write_cache = wc; 1601 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1602 VTBLK_UNLOCK(sc); 1603 1604 return (0); 1605 } 1606 1607 static void 1608 vtblk_setup_sysctl(struct vtblk_softc *sc) 1609 { 1610 device_t dev; 1611 struct sysctl_ctx_list *ctx; 1612 struct sysctl_oid *tree; 1613 struct sysctl_oid_list *child; 1614 1615 dev = sc->vtblk_dev; 1616 ctx = device_get_sysctl_ctx(dev); 1617 tree = device_get_sysctl_tree(dev); 1618 child = SYSCTL_CHILDREN(tree); 1619 1620 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1621 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0, 1622 vtblk_write_cache_sysctl, "I", 1623 "Write cache mode (writethrough (0) or writeback (1))"); 1624 } 1625 1626 static int 1627 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1628 { 1629 char path[64]; 1630 1631 snprintf(path, sizeof(path), 1632 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1633 TUNABLE_INT_FETCH(path, &def); 1634 1635 return (def); 1636 } 1637