1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #ifdef __powerpc__ 401 /* 402 * Virtio uses physical addresses rather than bus addresses, so we 403 * need to ask busdma to skip the iommu physical->bus mapping. At 404 * present, this is only a thing on the powerpc architectures. 405 */ 406 bus_dma_tag_set_iommu(sc->vtblk_dmat, NULL, NULL); 407 #endif 408 409 error = vtblk_alloc_virtqueue(sc); 410 if (error) { 411 device_printf(dev, "cannot allocate virtqueue\n"); 412 goto fail; 413 } 414 415 error = vtblk_request_prealloc(sc); 416 if (error) { 417 device_printf(dev, "cannot preallocate requests\n"); 418 goto fail; 419 } 420 421 vtblk_alloc_disk(sc, &blkcfg); 422 423 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 424 if (error) { 425 device_printf(dev, "cannot setup virtqueue interrupt\n"); 426 goto fail; 427 } 428 429 virtqueue_enable_intr(sc->vtblk_vq); 430 431 fail: 432 if (error) 433 vtblk_detach(dev); 434 435 return (error); 436 } 437 438 static int 439 vtblk_detach(device_t dev) 440 { 441 struct vtblk_softc *sc; 442 443 sc = device_get_softc(dev); 444 445 VTBLK_LOCK(sc); 446 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 447 if (device_is_attached(dev)) 448 vtblk_stop(sc); 449 VTBLK_UNLOCK(sc); 450 451 vtblk_drain(sc); 452 453 if (sc->vtblk_disk != NULL) { 454 disk_destroy(sc->vtblk_disk); 455 sc->vtblk_disk = NULL; 456 } 457 458 if (sc->vtblk_dmat != NULL) { 459 bus_dma_tag_destroy(sc->vtblk_dmat); 460 sc->vtblk_dmat = NULL; 461 } 462 463 if (sc->vtblk_sglist != NULL) { 464 sglist_free(sc->vtblk_sglist); 465 sc->vtblk_sglist = NULL; 466 } 467 468 VTBLK_LOCK_DESTROY(sc); 469 470 return (0); 471 } 472 473 static int 474 vtblk_suspend(device_t dev) 475 { 476 struct vtblk_softc *sc; 477 int error; 478 479 sc = device_get_softc(dev); 480 481 VTBLK_LOCK(sc); 482 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 483 /* XXX BMV: virtio_stop(), etc needed here? */ 484 error = vtblk_quiesce(sc); 485 if (error) 486 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 487 VTBLK_UNLOCK(sc); 488 489 return (error); 490 } 491 492 static int 493 vtblk_resume(device_t dev) 494 { 495 struct vtblk_softc *sc; 496 497 sc = device_get_softc(dev); 498 499 VTBLK_LOCK(sc); 500 /* XXX BMV: virtio_reinit(), etc needed here? */ 501 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 502 vtblk_startio(sc); 503 VTBLK_UNLOCK(sc); 504 505 return (0); 506 } 507 508 static int 509 vtblk_shutdown(device_t dev) 510 { 511 512 return (0); 513 } 514 515 static int 516 vtblk_attach_completed(device_t dev) 517 { 518 struct vtblk_softc *sc; 519 520 sc = device_get_softc(dev); 521 522 /* 523 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be 524 * processed after the device acknowledged 525 * VIRTIO_CONFIG_STATUS_DRIVER_OK. 526 */ 527 vtblk_create_disk(sc); 528 return (0); 529 } 530 531 static int 532 vtblk_config_change(device_t dev) 533 { 534 struct vtblk_softc *sc; 535 struct virtio_blk_config blkcfg; 536 uint64_t capacity; 537 538 sc = device_get_softc(dev); 539 540 vtblk_read_config(sc, &blkcfg); 541 542 /* Capacity is always in 512-byte units. */ 543 capacity = blkcfg.capacity * VTBLK_BSIZE; 544 545 if (sc->vtblk_disk->d_mediasize != capacity) 546 vtblk_resize_disk(sc, capacity); 547 548 return (0); 549 } 550 551 static int 552 vtblk_open(struct disk *dp) 553 { 554 struct vtblk_softc *sc; 555 556 if ((sc = dp->d_drv1) == NULL) 557 return (ENXIO); 558 559 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 560 } 561 562 static int 563 vtblk_close(struct disk *dp) 564 { 565 struct vtblk_softc *sc; 566 567 if ((sc = dp->d_drv1) == NULL) 568 return (ENXIO); 569 570 return (0); 571 } 572 573 static int 574 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 575 struct thread *td) 576 { 577 struct vtblk_softc *sc; 578 579 if ((sc = dp->d_drv1) == NULL) 580 return (ENXIO); 581 582 return (ENOTTY); 583 } 584 585 static int 586 vtblk_dump(void *arg, void *virtual, off_t offset, size_t length) 587 { 588 struct disk *dp; 589 struct vtblk_softc *sc; 590 int error; 591 592 dp = arg; 593 error = 0; 594 595 if ((sc = dp->d_drv1) == NULL) 596 return (ENXIO); 597 598 VTBLK_LOCK(sc); 599 600 vtblk_dump_quiesce(sc); 601 602 if (length > 0) 603 error = vtblk_dump_write(sc, virtual, offset, length); 604 if (error || (virtual == NULL && offset == 0)) 605 vtblk_dump_complete(sc); 606 607 VTBLK_UNLOCK(sc); 608 609 return (error); 610 } 611 612 static void 613 vtblk_strategy(struct bio *bp) 614 { 615 struct vtblk_softc *sc; 616 617 if ((sc = bp->bio_disk->d_drv1) == NULL) { 618 vtblk_bio_done(NULL, bp, EINVAL); 619 return; 620 } 621 622 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) && 623 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) { 624 vtblk_bio_done(sc, bp, EOPNOTSUPP); 625 return; 626 } 627 628 VTBLK_LOCK(sc); 629 630 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 631 VTBLK_UNLOCK(sc); 632 vtblk_bio_done(sc, bp, ENXIO); 633 return; 634 } 635 636 bioq_insert_tail(&sc->vtblk_bioq, bp); 637 vtblk_startio(sc); 638 639 VTBLK_UNLOCK(sc); 640 } 641 642 static int 643 vtblk_negotiate_features(struct vtblk_softc *sc) 644 { 645 device_t dev; 646 uint64_t features; 647 648 dev = sc->vtblk_dev; 649 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES : 650 VTBLK_LEGACY_FEATURES; 651 652 sc->vtblk_features = virtio_negotiate_features(dev, features); 653 return (virtio_finalize_features(dev)); 654 } 655 656 static int 657 vtblk_setup_features(struct vtblk_softc *sc) 658 { 659 device_t dev; 660 int error; 661 662 dev = sc->vtblk_dev; 663 664 error = vtblk_negotiate_features(sc); 665 if (error) 666 return (error); 667 668 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 669 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 670 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 671 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG; 672 673 /* Legacy. */ 674 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 675 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 676 677 return (0); 678 } 679 680 static int 681 vtblk_maximum_segments(struct vtblk_softc *sc, 682 struct virtio_blk_config *blkcfg) 683 { 684 device_t dev; 685 int nsegs; 686 687 dev = sc->vtblk_dev; 688 nsegs = VTBLK_MIN_SEGMENTS; 689 690 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 691 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1); 692 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 693 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 694 } else 695 nsegs += 1; 696 697 return (nsegs); 698 } 699 700 static int 701 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 702 { 703 device_t dev; 704 struct vq_alloc_info vq_info; 705 706 dev = sc->vtblk_dev; 707 708 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 709 vtblk_vq_intr, sc, &sc->vtblk_vq, 710 "%s request", device_get_nameunit(dev)); 711 712 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 713 } 714 715 static void 716 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 717 { 718 device_t dev; 719 struct disk *dp; 720 int error; 721 722 dev = sc->vtblk_dev; 723 dp = sc->vtblk_disk; 724 725 dp->d_mediasize = new_capacity; 726 if (bootverbose) { 727 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 728 (uintmax_t) dp->d_mediasize >> 20, 729 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 730 dp->d_sectorsize); 731 } 732 733 error = disk_resize(dp, M_NOWAIT); 734 if (error) { 735 device_printf(dev, 736 "disk_resize(9) failed, error: %d\n", error); 737 } 738 } 739 740 static void 741 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 742 { 743 device_t dev; 744 struct disk *dp; 745 746 dev = sc->vtblk_dev; 747 748 sc->vtblk_disk = dp = disk_alloc(); 749 dp->d_open = vtblk_open; 750 dp->d_close = vtblk_close; 751 dp->d_ioctl = vtblk_ioctl; 752 dp->d_strategy = vtblk_strategy; 753 dp->d_name = VTBLK_DISK_NAME; 754 dp->d_unit = device_get_unit(dev); 755 dp->d_drv1 = sc; 756 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION; 757 dp->d_hba_vendor = virtio_get_vendor(dev); 758 dp->d_hba_device = virtio_get_device(dev); 759 dp->d_hba_subvendor = virtio_get_subvendor(dev); 760 dp->d_hba_subdevice = virtio_get_subdevice(dev); 761 762 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 763 dp->d_flags |= DISKFLAG_WRITE_PROTECT; 764 else { 765 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 766 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 767 dp->d_dump = vtblk_dump; 768 } 769 770 /* Capacity is always in 512-byte units. */ 771 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE; 772 773 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 774 dp->d_sectorsize = blkcfg->blk_size; 775 else 776 dp->d_sectorsize = VTBLK_BSIZE; 777 778 /* 779 * The VirtIO maximum I/O size is given in terms of segments. 780 * However, FreeBSD limits I/O size by logical buffer size, not 781 * by physically contiguous pages. Therefore, we have to assume 782 * no pages are contiguous. This may impose an artificially low 783 * maximum I/O size. But in practice, since QEMU advertises 128 784 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 785 * which is typically greater than maxphys. Eventually we should 786 * just advertise maxphys and split buffers that are too big. 787 * 788 * If we're not asking busdma to align data to page boundaries, the 789 * maximum I/O size is reduced by PAGE_SIZE in order to accommodate 790 * unaligned I/Os. 791 */ 792 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS) * 793 PAGE_SIZE; 794 if ((sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) == 0) 795 dp->d_maxsize -= PAGE_SIZE; 796 797 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 798 dp->d_fwsectors = blkcfg->geometry.sectors; 799 dp->d_fwheads = blkcfg->geometry.heads; 800 } 801 802 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 803 blkcfg->topology.physical_block_exp > 0) { 804 dp->d_stripesize = dp->d_sectorsize * 805 (1 << blkcfg->topology.physical_block_exp); 806 dp->d_stripeoffset = (dp->d_stripesize - 807 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 808 dp->d_stripesize; 809 } 810 811 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) { 812 dp->d_flags |= DISKFLAG_CANDELETE; 813 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE; 814 } 815 816 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 817 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 818 else 819 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 820 } 821 822 static void 823 vtblk_create_disk(struct vtblk_softc *sc) 824 { 825 struct disk *dp; 826 827 dp = sc->vtblk_disk; 828 829 vtblk_ident(sc); 830 831 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 832 (uintmax_t) dp->d_mediasize >> 20, 833 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 834 dp->d_sectorsize); 835 836 disk_create(dp, DISK_VERSION); 837 } 838 839 static int 840 vtblk_request_prealloc(struct vtblk_softc *sc) 841 { 842 struct vtblk_request *req; 843 int i, nreqs; 844 845 nreqs = virtqueue_size(sc->vtblk_vq); 846 847 /* 848 * Preallocate sufficient requests to keep the virtqueue full. Each 849 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 850 * the number allocated when indirect descriptors are not available. 851 */ 852 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 853 nreqs /= VTBLK_MIN_SEGMENTS; 854 855 for (i = 0; i < nreqs; i++) { 856 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 857 if (req == NULL) 858 return (ENOMEM); 859 860 req->vbr_sc = sc; 861 if (bus_dmamap_create(sc->vtblk_dmat, 0, &req->vbr_mapp)) { 862 free(req, M_DEVBUF); 863 return (ENOMEM); 864 } 865 866 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 867 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 868 869 sc->vtblk_request_count++; 870 vtblk_request_enqueue(sc, req); 871 } 872 873 return (0); 874 } 875 876 static void 877 vtblk_request_free(struct vtblk_softc *sc) 878 { 879 struct vtblk_request *req; 880 881 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 882 883 while ((req = vtblk_request_dequeue(sc)) != NULL) { 884 sc->vtblk_request_count--; 885 bus_dmamap_destroy(sc->vtblk_dmat, req->vbr_mapp); 886 free(req, M_DEVBUF); 887 } 888 889 KASSERT(sc->vtblk_request_count == 0, 890 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 891 } 892 893 static struct vtblk_request * 894 vtblk_request_dequeue(struct vtblk_softc *sc) 895 { 896 struct vtblk_request *req; 897 898 req = TAILQ_FIRST(&sc->vtblk_req_free); 899 if (req != NULL) { 900 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 901 bzero(&req->vbr_hdr, sizeof(struct vtblk_request) - 902 offsetof(struct vtblk_request, vbr_hdr)); 903 } 904 905 return (req); 906 } 907 908 static void 909 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 910 { 911 912 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 913 } 914 915 static struct vtblk_request * 916 vtblk_request_next_ready(struct vtblk_softc *sc) 917 { 918 struct vtblk_request *req; 919 920 req = TAILQ_FIRST(&sc->vtblk_req_ready); 921 if (req != NULL) 922 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 923 924 return (req); 925 } 926 927 static void 928 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 929 { 930 931 /* NOTE: Currently, there will be at most one request in the queue. */ 932 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 933 } 934 935 static struct vtblk_request * 936 vtblk_request_next(struct vtblk_softc *sc) 937 { 938 struct vtblk_request *req; 939 940 req = vtblk_request_next_ready(sc); 941 if (req != NULL) 942 return (req); 943 944 return (vtblk_request_bio(sc)); 945 } 946 947 static struct vtblk_request * 948 vtblk_request_bio(struct vtblk_softc *sc) 949 { 950 struct bio_queue_head *bioq; 951 struct vtblk_request *req; 952 struct bio *bp; 953 954 bioq = &sc->vtblk_bioq; 955 956 if (bioq_first(bioq) == NULL) 957 return (NULL); 958 959 req = vtblk_request_dequeue(sc); 960 if (req == NULL) 961 return (NULL); 962 963 bp = bioq_takefirst(bioq); 964 req->vbr_bp = bp; 965 req->vbr_ack = -1; 966 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 967 968 switch (bp->bio_cmd) { 969 case BIO_FLUSH: 970 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 971 req->vbr_hdr.sector = 0; 972 break; 973 case BIO_READ: 974 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN); 975 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 976 break; 977 case BIO_WRITE: 978 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 979 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 980 break; 981 case BIO_DELETE: 982 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD); 983 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 984 break; 985 default: 986 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 987 } 988 989 if (bp->bio_flags & BIO_ORDERED) 990 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER); 991 992 return (req); 993 } 994 995 static int 996 vtblk_request_execute(struct vtblk_request *req, int flags) 997 { 998 struct vtblk_softc *sc = req->vbr_sc; 999 struct bio *bp = req->vbr_bp; 1000 int error = 0; 1001 1002 /* 1003 * Call via bus_dmamap_load_bio or directly depending on whether we 1004 * have a buffer we need to map. If we don't have a busdma map, 1005 * try to perform the I/O directly and hope that it works (this will 1006 * happen when dumping). 1007 */ 1008 if ((req->vbr_mapp != NULL) && 1009 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) { 1010 error = bus_dmamap_load_bio(sc->vtblk_dmat, req->vbr_mapp, 1011 req->vbr_bp, vtblk_request_execute_cb, req, flags); 1012 if (error == EINPROGRESS) { 1013 req->vbr_busdma_wait = 1; 1014 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_WAIT; 1015 } 1016 } else { 1017 vtblk_request_execute_cb(req, NULL, 0, 0); 1018 } 1019 1020 return (error ? error : req->vbr_error); 1021 } 1022 1023 static void 1024 vtblk_request_execute_cb(void * callback_arg, bus_dma_segment_t * segs, 1025 int nseg, int error) 1026 { 1027 struct vtblk_request *req; 1028 struct vtblk_softc *sc; 1029 struct virtqueue *vq; 1030 struct sglist *sg; 1031 struct bio *bp; 1032 int ordered, readable, writable, i; 1033 1034 req = (struct vtblk_request *)callback_arg; 1035 sc = req->vbr_sc; 1036 vq = sc->vtblk_vq; 1037 sg = sc->vtblk_sglist; 1038 bp = req->vbr_bp; 1039 ordered = 0; 1040 writable = 0; 1041 1042 /* 1043 * If we paused request queueing while we waited for busdma to call us 1044 * asynchronously, unpause it now; this request made it through so we 1045 * don't need to worry about others getting ahead of us. (Note that we 1046 * hold the device mutex so nothing will happen until after we return 1047 * anyway.) 1048 */ 1049 if (req->vbr_busdma_wait) 1050 sc->vtblk_flags &= ~VTBLK_FLAG_BUSDMA_WAIT; 1051 1052 /* Fail on errors from busdma. */ 1053 if (error) 1054 goto out1; 1055 1056 /* 1057 * Some hosts (such as bhyve) do not implement the barrier feature, 1058 * so we emulate it in the driver by allowing the barrier request 1059 * to be the only one in flight. 1060 */ 1061 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 1062 if (sc->vtblk_req_ordered != NULL) { 1063 error = EBUSY; 1064 goto out; 1065 } 1066 if (bp->bio_flags & BIO_ORDERED) { 1067 if (!virtqueue_empty(vq)) { 1068 error = EBUSY; 1069 goto out; 1070 } 1071 ordered = 1; 1072 req->vbr_hdr.type &= vtblk_gtoh32(sc, 1073 ~VIRTIO_BLK_T_BARRIER); 1074 } 1075 } 1076 1077 sglist_reset(sg); 1078 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 1079 1080 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 1081 /* 1082 * We cast bus_addr_t to vm_paddr_t here; since we skip the 1083 * iommu mapping (see vtblk_attach) this should be safe. 1084 */ 1085 for (i = 0; i < nseg; i++) { 1086 error = sglist_append_phys(sg, 1087 (vm_paddr_t)segs[i].ds_addr, segs[i].ds_len); 1088 if (error || sg->sg_nseg == sg->sg_maxseg) { 1089 panic("%s: bio %p data buffer too big %d", 1090 __func__, bp, error); 1091 } 1092 } 1093 1094 /* Special handling for dump, which bypasses busdma. */ 1095 if (req->vbr_mapp == NULL) { 1096 error = sglist_append_bio(sg, bp); 1097 if (error || sg->sg_nseg == sg->sg_maxseg) { 1098 panic("%s: bio %p data buffer too big %d", 1099 __func__, bp, error); 1100 } 1101 } 1102 1103 /* BIO_READ means the host writes into our buffer. */ 1104 if (bp->bio_cmd == BIO_READ) 1105 writable = sg->sg_nseg - 1; 1106 } else if (bp->bio_cmd == BIO_DELETE) { 1107 struct virtio_blk_discard_write_zeroes *discard; 1108 1109 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO); 1110 if (discard == NULL) { 1111 error = ENOMEM; 1112 goto out; 1113 } 1114 1115 bp->bio_driver1 = discard; 1116 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 1117 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE); 1118 error = sglist_append(sg, discard, sizeof(*discard)); 1119 if (error || sg->sg_nseg == sg->sg_maxseg) { 1120 panic("%s: bio %p data buffer too big %d", 1121 __func__, bp, error); 1122 } 1123 } 1124 1125 writable++; 1126 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 1127 readable = sg->sg_nseg - writable; 1128 1129 if (req->vbr_mapp != NULL) { 1130 switch (bp->bio_cmd) { 1131 case BIO_READ: 1132 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1133 BUS_DMASYNC_PREREAD); 1134 break; 1135 case BIO_WRITE: 1136 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1137 BUS_DMASYNC_PREWRITE); 1138 break; 1139 } 1140 } 1141 1142 error = virtqueue_enqueue(vq, req, sg, readable, writable); 1143 if (error == 0 && ordered) 1144 sc->vtblk_req_ordered = req; 1145 1146 /* 1147 * If we were called asynchronously, we need to notify the queue that 1148 * we've added a new request, since the notification from startio was 1149 * performed already. 1150 */ 1151 if (error == 0 && req->vbr_busdma_wait) 1152 virtqueue_notify(vq); 1153 1154 out: 1155 if (error && (req->vbr_mapp != NULL)) 1156 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp); 1157 out1: 1158 if (error && req->vbr_requeue_on_error) 1159 vtblk_request_requeue_ready(sc, req); 1160 req->vbr_error = error; 1161 } 1162 1163 static int 1164 vtblk_request_error(struct vtblk_request *req) 1165 { 1166 int error; 1167 1168 switch (req->vbr_ack) { 1169 case VIRTIO_BLK_S_OK: 1170 error = 0; 1171 break; 1172 case VIRTIO_BLK_S_UNSUPP: 1173 error = ENOTSUP; 1174 break; 1175 default: 1176 error = EIO; 1177 break; 1178 } 1179 1180 return (error); 1181 } 1182 1183 static void 1184 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1185 { 1186 struct vtblk_request *req; 1187 struct bio *bp; 1188 1189 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1190 if (sc->vtblk_req_ordered != NULL) { 1191 MPASS(sc->vtblk_req_ordered == req); 1192 sc->vtblk_req_ordered = NULL; 1193 } 1194 1195 bp = req->vbr_bp; 1196 if (req->vbr_mapp != NULL) { 1197 switch (bp->bio_cmd) { 1198 case BIO_READ: 1199 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1200 BUS_DMASYNC_POSTREAD); 1201 bus_dmamap_unload(sc->vtblk_dmat, 1202 req->vbr_mapp); 1203 break; 1204 case BIO_WRITE: 1205 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1206 BUS_DMASYNC_POSTWRITE); 1207 bus_dmamap_unload(sc->vtblk_dmat, 1208 req->vbr_mapp); 1209 break; 1210 } 1211 } 1212 bp->bio_error = vtblk_request_error(req); 1213 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 1214 1215 vtblk_request_enqueue(sc, req); 1216 } 1217 } 1218 1219 static void 1220 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1221 { 1222 struct bio *bp, *tmp; 1223 1224 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 1225 if (bp->bio_error != 0) 1226 disk_err(bp, "hard error", -1, 1); 1227 vtblk_bio_done(sc, bp, bp->bio_error); 1228 } 1229 } 1230 1231 static void 1232 vtblk_drain_vq(struct vtblk_softc *sc) 1233 { 1234 struct virtqueue *vq; 1235 struct vtblk_request *req; 1236 int last; 1237 1238 vq = sc->vtblk_vq; 1239 last = 0; 1240 1241 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1242 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1243 vtblk_request_enqueue(sc, req); 1244 } 1245 1246 sc->vtblk_req_ordered = NULL; 1247 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1248 } 1249 1250 static void 1251 vtblk_drain(struct vtblk_softc *sc) 1252 { 1253 struct bio_queue_head *bioq; 1254 struct vtblk_request *req; 1255 struct bio *bp; 1256 1257 bioq = &sc->vtblk_bioq; 1258 1259 if (sc->vtblk_vq != NULL) { 1260 struct bio_queue queue; 1261 1262 TAILQ_INIT(&queue); 1263 vtblk_queue_completed(sc, &queue); 1264 vtblk_done_completed(sc, &queue); 1265 1266 vtblk_drain_vq(sc); 1267 } 1268 1269 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1270 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1271 vtblk_request_enqueue(sc, req); 1272 } 1273 1274 while (bioq_first(bioq) != NULL) { 1275 bp = bioq_takefirst(bioq); 1276 vtblk_bio_done(sc, bp, ENXIO); 1277 } 1278 1279 vtblk_request_free(sc); 1280 } 1281 1282 static void 1283 vtblk_startio(struct vtblk_softc *sc) 1284 { 1285 struct virtqueue *vq; 1286 struct vtblk_request *req; 1287 int enq; 1288 1289 VTBLK_LOCK_ASSERT(sc); 1290 vq = sc->vtblk_vq; 1291 enq = 0; 1292 1293 if (sc->vtblk_flags & (VTBLK_FLAG_SUSPEND | VTBLK_FLAG_BUSDMA_WAIT)) 1294 return; 1295 1296 while (!virtqueue_full(vq)) { 1297 req = vtblk_request_next(sc); 1298 if (req == NULL) 1299 break; 1300 1301 req->vbr_requeue_on_error = 1; 1302 if (vtblk_request_execute(req, BUS_DMA_WAITOK)) 1303 break; 1304 1305 enq++; 1306 } 1307 1308 if (enq > 0) 1309 virtqueue_notify(vq); 1310 } 1311 1312 static void 1313 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1314 { 1315 1316 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1317 if (sc != NULL) 1318 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1319 1320 if (error) { 1321 bp->bio_resid = bp->bio_bcount; 1322 bp->bio_error = error; 1323 bp->bio_flags |= BIO_ERROR; 1324 } else { 1325 kmsan_mark_bio(bp, KMSAN_STATE_INITED); 1326 } 1327 1328 if (bp->bio_driver1 != NULL) { 1329 free(bp->bio_driver1, M_DEVBUF); 1330 bp->bio_driver1 = NULL; 1331 } 1332 1333 biodone(bp); 1334 } 1335 1336 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1337 if (virtio_with_feature(_dev, _feature)) { \ 1338 virtio_read_device_config(_dev, \ 1339 offsetof(struct virtio_blk_config, _field), \ 1340 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1341 } 1342 1343 static void 1344 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1345 { 1346 device_t dev; 1347 1348 dev = sc->vtblk_dev; 1349 1350 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1351 1352 /* The capacity is always available. */ 1353 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1354 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1355 1356 /* Read the configuration if the feature was negotiated. */ 1357 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1358 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1359 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1360 geometry.cylinders, blkcfg); 1361 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1362 geometry.heads, blkcfg); 1363 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1364 geometry.sectors, blkcfg); 1365 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1366 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1367 topology.physical_block_exp, blkcfg); 1368 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1369 topology.alignment_offset, blkcfg); 1370 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1371 topology.min_io_size, blkcfg); 1372 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1373 topology.opt_io_size, blkcfg); 1374 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg); 1375 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors, 1376 blkcfg); 1377 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg); 1378 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment, 1379 blkcfg); 1380 } 1381 1382 #undef VTBLK_GET_CONFIG 1383 1384 static void 1385 vtblk_ident(struct vtblk_softc *sc) 1386 { 1387 struct bio buf; 1388 struct disk *dp; 1389 struct vtblk_request *req; 1390 int len, error; 1391 1392 dp = sc->vtblk_disk; 1393 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1394 1395 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1396 return; 1397 1398 req = vtblk_request_dequeue(sc); 1399 if (req == NULL) 1400 return; 1401 1402 req->vbr_ack = -1; 1403 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID); 1404 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1405 req->vbr_hdr.sector = 0; 1406 1407 req->vbr_bp = &buf; 1408 g_reset_bio(&buf); 1409 1410 buf.bio_cmd = BIO_READ; 1411 buf.bio_data = dp->d_ident; 1412 buf.bio_bcount = len; 1413 1414 VTBLK_LOCK(sc); 1415 error = vtblk_poll_request(sc, req); 1416 VTBLK_UNLOCK(sc); 1417 1418 vtblk_request_enqueue(sc, req); 1419 1420 if (error) { 1421 device_printf(sc->vtblk_dev, 1422 "error getting device identifier: %d\n", error); 1423 } 1424 } 1425 1426 static int 1427 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1428 { 1429 struct virtqueue *vq; 1430 int error; 1431 1432 vq = sc->vtblk_vq; 1433 1434 if (!virtqueue_empty(vq)) 1435 return (EBUSY); 1436 1437 error = vtblk_request_execute(req, BUS_DMA_NOWAIT); 1438 if (error) 1439 return (error); 1440 1441 virtqueue_notify(vq); 1442 virtqueue_poll(vq, NULL); 1443 1444 error = vtblk_request_error(req); 1445 if (error && bootverbose) { 1446 device_printf(sc->vtblk_dev, 1447 "%s: IO error: %d\n", __func__, error); 1448 } 1449 1450 return (error); 1451 } 1452 1453 static int 1454 vtblk_quiesce(struct vtblk_softc *sc) 1455 { 1456 int error; 1457 1458 VTBLK_LOCK_ASSERT(sc); 1459 error = 0; 1460 1461 while (!virtqueue_empty(sc->vtblk_vq)) { 1462 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1463 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1464 error = EBUSY; 1465 break; 1466 } 1467 } 1468 1469 return (error); 1470 } 1471 1472 static void 1473 vtblk_vq_intr(void *xsc) 1474 { 1475 struct vtblk_softc *sc; 1476 struct virtqueue *vq; 1477 struct bio_queue queue; 1478 1479 sc = xsc; 1480 vq = sc->vtblk_vq; 1481 TAILQ_INIT(&queue); 1482 1483 VTBLK_LOCK(sc); 1484 1485 again: 1486 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1487 goto out; 1488 1489 vtblk_queue_completed(sc, &queue); 1490 vtblk_startio(sc); 1491 1492 if (virtqueue_enable_intr(vq) != 0) { 1493 virtqueue_disable_intr(vq); 1494 goto again; 1495 } 1496 1497 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1498 wakeup(&sc->vtblk_vq); 1499 1500 out: 1501 VTBLK_UNLOCK(sc); 1502 vtblk_done_completed(sc, &queue); 1503 } 1504 1505 static void 1506 vtblk_stop(struct vtblk_softc *sc) 1507 { 1508 1509 virtqueue_disable_intr(sc->vtblk_vq); 1510 virtio_stop(sc->vtblk_dev); 1511 } 1512 1513 static void 1514 vtblk_dump_quiesce(struct vtblk_softc *sc) 1515 { 1516 1517 /* 1518 * Spin here until all the requests in-flight at the time of the 1519 * dump are completed and queued. The queued requests will be 1520 * biodone'd once the dump is finished. 1521 */ 1522 while (!virtqueue_empty(sc->vtblk_vq)) 1523 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1524 } 1525 1526 static int 1527 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1528 size_t length) 1529 { 1530 struct bio buf; 1531 struct vtblk_request *req; 1532 1533 req = &sc->vtblk_dump_request; 1534 req->vbr_sc = sc; 1535 req->vbr_ack = -1; 1536 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 1537 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1538 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE); 1539 1540 req->vbr_bp = &buf; 1541 g_reset_bio(&buf); 1542 1543 buf.bio_cmd = BIO_WRITE; 1544 buf.bio_data = virtual; 1545 buf.bio_bcount = length; 1546 1547 return (vtblk_poll_request(sc, req)); 1548 } 1549 1550 static int 1551 vtblk_dump_flush(struct vtblk_softc *sc) 1552 { 1553 struct bio buf; 1554 struct vtblk_request *req; 1555 1556 req = &sc->vtblk_dump_request; 1557 req->vbr_sc = sc; 1558 req->vbr_ack = -1; 1559 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 1560 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1561 req->vbr_hdr.sector = 0; 1562 1563 req->vbr_bp = &buf; 1564 g_reset_bio(&buf); 1565 1566 buf.bio_cmd = BIO_FLUSH; 1567 1568 return (vtblk_poll_request(sc, req)); 1569 } 1570 1571 static void 1572 vtblk_dump_complete(struct vtblk_softc *sc) 1573 { 1574 1575 vtblk_dump_flush(sc); 1576 1577 VTBLK_UNLOCK(sc); 1578 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1579 VTBLK_LOCK(sc); 1580 } 1581 1582 static void 1583 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1584 { 1585 1586 /* Set either writeback (1) or writethrough (0) mode. */ 1587 virtio_write_dev_config_1(sc->vtblk_dev, 1588 offsetof(struct virtio_blk_config, wce), wc); 1589 } 1590 1591 static int 1592 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1593 struct virtio_blk_config *blkcfg) 1594 { 1595 int wc; 1596 1597 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) { 1598 wc = vtblk_tunable_int(sc, "writecache_mode", 1599 vtblk_writecache_mode); 1600 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1601 vtblk_set_write_cache(sc, wc); 1602 else 1603 wc = blkcfg->wce; 1604 } else 1605 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH); 1606 1607 return (wc); 1608 } 1609 1610 static int 1611 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1612 { 1613 struct vtblk_softc *sc; 1614 int wc, error; 1615 1616 sc = oidp->oid_arg1; 1617 wc = sc->vtblk_write_cache; 1618 1619 error = sysctl_handle_int(oidp, &wc, 0, req); 1620 if (error || req->newptr == NULL) 1621 return (error); 1622 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0) 1623 return (EPERM); 1624 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1625 return (EINVAL); 1626 1627 VTBLK_LOCK(sc); 1628 sc->vtblk_write_cache = wc; 1629 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1630 VTBLK_UNLOCK(sc); 1631 1632 return (0); 1633 } 1634 1635 static void 1636 vtblk_setup_sysctl(struct vtblk_softc *sc) 1637 { 1638 device_t dev; 1639 struct sysctl_ctx_list *ctx; 1640 struct sysctl_oid *tree; 1641 struct sysctl_oid_list *child; 1642 1643 dev = sc->vtblk_dev; 1644 ctx = device_get_sysctl_ctx(dev); 1645 tree = device_get_sysctl_tree(dev); 1646 child = SYSCTL_CHILDREN(tree); 1647 1648 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1649 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0, 1650 vtblk_write_cache_sysctl, "I", 1651 "Write cache mode (writethrough (0) or writeback (1))"); 1652 } 1653 1654 static int 1655 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1656 { 1657 char path[64]; 1658 1659 snprintf(path, sizeof(path), 1660 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1661 TUNABLE_INT_FETCH(path, &def); 1662 1663 return (def); 1664 } 1665