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/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/bio.h> 35 #include <sys/malloc.h> 36 #include <sys/module.h> 37 #include <sys/msan.h> 38 #include <sys/sglist.h> 39 #include <sys/sysctl.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/queue.h> 43 44 #include <geom/geom.h> 45 #include <geom/geom_disk.h> 46 47 #include <machine/bus.h> 48 #include <machine/resource.h> 49 #include <sys/bus.h> 50 #include <sys/rman.h> 51 52 #include <dev/virtio/virtio.h> 53 #include <dev/virtio/virtqueue.h> 54 #include <dev/virtio/block/virtio_blk.h> 55 56 #include "virtio_if.h" 57 58 struct vtblk_request { 59 struct vtblk_softc *vbr_sc; 60 bus_dmamap_t vbr_mapp; 61 62 /* Fields after this point are zeroed for each request. */ 63 struct virtio_blk_outhdr vbr_hdr; 64 struct bio *vbr_bp; 65 uint8_t vbr_ack; 66 uint8_t vbr_requeue_on_error; 67 uint8_t vbr_busdma_wait; 68 int vbr_error; 69 TAILQ_ENTRY(vtblk_request) vbr_link; 70 }; 71 72 enum vtblk_cache_mode { 73 VTBLK_CACHE_WRITETHROUGH, 74 VTBLK_CACHE_WRITEBACK, 75 VTBLK_CACHE_MAX 76 }; 77 78 struct vtblk_softc { 79 device_t vtblk_dev; 80 struct mtx vtblk_mtx; 81 uint64_t vtblk_features; 82 uint32_t vtblk_flags; 83 #define VTBLK_FLAG_INDIRECT 0x0001 84 #define VTBLK_FLAG_DETACH 0x0002 85 #define VTBLK_FLAG_SUSPEND 0x0004 86 #define VTBLK_FLAG_BARRIER 0x0008 87 #define VTBLK_FLAG_WCE_CONFIG 0x0010 88 #define VTBLK_FLAG_BUSDMA_WAIT 0x0020 89 #define VTBLK_FLAG_BUSDMA_ALIGN 0x0040 90 91 struct virtqueue *vtblk_vq; 92 struct sglist *vtblk_sglist; 93 bus_dma_tag_t vtblk_dmat; 94 struct disk *vtblk_disk; 95 96 struct bio_queue_head vtblk_bioq; 97 TAILQ_HEAD(, vtblk_request) 98 vtblk_req_free; 99 TAILQ_HEAD(, vtblk_request) 100 vtblk_req_ready; 101 struct vtblk_request *vtblk_req_ordered; 102 103 int vtblk_max_nsegs; 104 int vtblk_request_count; 105 enum vtblk_cache_mode vtblk_write_cache; 106 107 struct bio_queue vtblk_dump_queue; 108 struct vtblk_request vtblk_dump_request; 109 }; 110 111 static struct virtio_feature_desc vtblk_feature_desc[] = { 112 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 113 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 114 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 115 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 116 { VIRTIO_BLK_F_RO, "ReadOnly" }, 117 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 118 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 119 { VIRTIO_BLK_F_FLUSH, "FlushCmd" }, 120 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 121 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, 122 { VIRTIO_BLK_F_MQ, "Multiqueue" }, 123 { VIRTIO_BLK_F_DISCARD, "Discard" }, 124 { VIRTIO_BLK_F_WRITE_ZEROES, "WriteZeros" }, 125 126 { 0, NULL } 127 }; 128 129 static int vtblk_modevent(module_t, int, void *); 130 131 static int vtblk_probe(device_t); 132 static int vtblk_attach(device_t); 133 static int vtblk_detach(device_t); 134 static int vtblk_suspend(device_t); 135 static int vtblk_resume(device_t); 136 static int vtblk_shutdown(device_t); 137 static int vtblk_attach_completed(device_t); 138 static int vtblk_config_change(device_t); 139 140 static int vtblk_open(struct disk *); 141 static int vtblk_close(struct disk *); 142 static int vtblk_ioctl(struct disk *, u_long, void *, int, 143 struct thread *); 144 static int vtblk_dump(void *, void *, off_t, size_t); 145 static void vtblk_strategy(struct bio *); 146 147 static int vtblk_negotiate_features(struct vtblk_softc *); 148 static int vtblk_setup_features(struct vtblk_softc *); 149 static int vtblk_maximum_segments(struct vtblk_softc *, 150 struct virtio_blk_config *); 151 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 152 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 153 static void vtblk_alloc_disk(struct vtblk_softc *, 154 struct virtio_blk_config *); 155 static void vtblk_create_disk(struct vtblk_softc *); 156 157 static int vtblk_request_prealloc(struct vtblk_softc *); 158 static void vtblk_request_free(struct vtblk_softc *); 159 static struct vtblk_request * 160 vtblk_request_dequeue(struct vtblk_softc *); 161 static void vtblk_request_enqueue(struct vtblk_softc *, 162 struct vtblk_request *); 163 static struct vtblk_request * 164 vtblk_request_next_ready(struct vtblk_softc *); 165 static void vtblk_request_requeue_ready(struct vtblk_softc *, 166 struct vtblk_request *); 167 static struct vtblk_request * 168 vtblk_request_next(struct vtblk_softc *); 169 static struct vtblk_request * 170 vtblk_request_bio(struct vtblk_softc *); 171 static int vtblk_request_execute(struct vtblk_request *, int); 172 static void vtblk_request_execute_cb(void *, 173 bus_dma_segment_t *, int, int); 174 static int vtblk_request_error(struct vtblk_request *); 175 176 static void vtblk_queue_completed(struct vtblk_softc *, 177 struct bio_queue *); 178 static void vtblk_done_completed(struct vtblk_softc *, 179 struct bio_queue *); 180 static void vtblk_drain_vq(struct vtblk_softc *); 181 static void vtblk_drain(struct vtblk_softc *); 182 183 static void vtblk_startio(struct vtblk_softc *); 184 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 185 186 static void vtblk_read_config(struct vtblk_softc *, 187 struct virtio_blk_config *); 188 static void vtblk_ident(struct vtblk_softc *); 189 static int vtblk_poll_request(struct vtblk_softc *, 190 struct vtblk_request *); 191 static int vtblk_quiesce(struct vtblk_softc *); 192 static void vtblk_vq_intr(void *); 193 static void vtblk_stop(struct vtblk_softc *); 194 195 static void vtblk_dump_quiesce(struct vtblk_softc *); 196 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 197 static int vtblk_dump_flush(struct vtblk_softc *); 198 static void vtblk_dump_complete(struct vtblk_softc *); 199 200 static void vtblk_set_write_cache(struct vtblk_softc *, int); 201 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 202 struct virtio_blk_config *); 203 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 204 205 static void vtblk_setup_sysctl(struct vtblk_softc *); 206 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 207 208 #define vtblk_modern(_sc) (((_sc)->vtblk_features & VIRTIO_F_VERSION_1) != 0) 209 #define vtblk_htog16(_sc, _val) virtio_htog16(vtblk_modern(_sc), _val) 210 #define vtblk_htog32(_sc, _val) virtio_htog32(vtblk_modern(_sc), _val) 211 #define vtblk_htog64(_sc, _val) virtio_htog64(vtblk_modern(_sc), _val) 212 #define vtblk_gtoh16(_sc, _val) virtio_gtoh16(vtblk_modern(_sc), _val) 213 #define vtblk_gtoh32(_sc, _val) virtio_gtoh32(vtblk_modern(_sc), _val) 214 #define vtblk_gtoh64(_sc, _val) virtio_gtoh64(vtblk_modern(_sc), _val) 215 216 /* Tunables. */ 217 static int vtblk_no_ident = 0; 218 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 219 static int vtblk_writecache_mode = -1; 220 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 221 222 #define VTBLK_COMMON_FEATURES \ 223 (VIRTIO_BLK_F_SIZE_MAX | \ 224 VIRTIO_BLK_F_SEG_MAX | \ 225 VIRTIO_BLK_F_GEOMETRY | \ 226 VIRTIO_BLK_F_RO | \ 227 VIRTIO_BLK_F_BLK_SIZE | \ 228 VIRTIO_BLK_F_FLUSH | \ 229 VIRTIO_BLK_F_TOPOLOGY | \ 230 VIRTIO_BLK_F_CONFIG_WCE | \ 231 VIRTIO_BLK_F_DISCARD | \ 232 VIRTIO_RING_F_INDIRECT_DESC) 233 234 #define VTBLK_MODERN_FEATURES (VTBLK_COMMON_FEATURES) 235 #define VTBLK_LEGACY_FEATURES (VIRTIO_BLK_F_BARRIER | VTBLK_COMMON_FEATURES) 236 237 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 238 #define VTBLK_LOCK_INIT(_sc, _name) \ 239 mtx_init(VTBLK_MTX((_sc)), (_name), \ 240 "VirtIO Block Lock", MTX_DEF) 241 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 242 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 243 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 244 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 245 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 246 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 247 248 #define VTBLK_DISK_NAME "vtbd" 249 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 250 #define VTBLK_BSIZE 512 251 252 /* 253 * Each block request uses at least two segments - one for the header 254 * and one for the status. 255 */ 256 #define VTBLK_MIN_SEGMENTS 2 257 258 static device_method_t vtblk_methods[] = { 259 /* Device methods. */ 260 DEVMETHOD(device_probe, vtblk_probe), 261 DEVMETHOD(device_attach, vtblk_attach), 262 DEVMETHOD(device_detach, vtblk_detach), 263 DEVMETHOD(device_suspend, vtblk_suspend), 264 DEVMETHOD(device_resume, vtblk_resume), 265 DEVMETHOD(device_shutdown, vtblk_shutdown), 266 267 /* VirtIO methods. */ 268 DEVMETHOD(virtio_attach_completed, vtblk_attach_completed), 269 DEVMETHOD(virtio_config_change, vtblk_config_change), 270 271 DEVMETHOD_END 272 }; 273 274 static driver_t vtblk_driver = { 275 "vtblk", 276 vtblk_methods, 277 sizeof(struct vtblk_softc) 278 }; 279 280 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_modevent, NULL); 281 MODULE_VERSION(virtio_blk, 1); 282 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 283 284 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter"); 285 286 static int 287 vtblk_modevent(module_t mod, int type, void *unused) 288 { 289 int error; 290 291 error = 0; 292 293 switch (type) { 294 case MOD_LOAD: 295 case MOD_QUIESCE: 296 case MOD_UNLOAD: 297 case MOD_SHUTDOWN: 298 break; 299 default: 300 error = EOPNOTSUPP; 301 break; 302 } 303 304 return (error); 305 } 306 307 static int 308 vtblk_probe(device_t dev) 309 { 310 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk)); 311 } 312 313 static int 314 vtblk_attach(device_t dev) 315 { 316 struct vtblk_softc *sc; 317 struct virtio_blk_config blkcfg; 318 int error; 319 320 sc = device_get_softc(dev); 321 sc->vtblk_dev = dev; 322 virtio_set_feature_desc(dev, vtblk_feature_desc); 323 324 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 325 bioq_init(&sc->vtblk_bioq); 326 TAILQ_INIT(&sc->vtblk_dump_queue); 327 TAILQ_INIT(&sc->vtblk_req_free); 328 TAILQ_INIT(&sc->vtblk_req_ready); 329 330 vtblk_setup_sysctl(sc); 331 332 error = vtblk_setup_features(sc); 333 if (error) { 334 device_printf(dev, "cannot setup features\n"); 335 goto fail; 336 } 337 338 vtblk_read_config(sc, &blkcfg); 339 340 /* 341 * With the current sglist(9) implementation, it is not easy 342 * for us to support a maximum segment size as adjacent 343 * segments are coalesced. For now, just make sure it's larger 344 * than the maximum supported transfer size. 345 */ 346 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 347 if (blkcfg.size_max < maxphys) { 348 error = ENOTSUP; 349 device_printf(dev, "host requires unsupported " 350 "maximum segment size feature\n"); 351 goto fail; 352 } 353 } 354 355 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 356 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 357 error = EINVAL; 358 device_printf(dev, "fewer than minimum number of segments " 359 "allowed: %d\n", sc->vtblk_max_nsegs); 360 goto fail; 361 } 362 363 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 364 if (sc->vtblk_sglist == NULL) { 365 error = ENOMEM; 366 device_printf(dev, "cannot allocate sglist\n"); 367 goto fail; 368 } 369 370 /* 371 * If vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1, the device only 372 * supports a single data segment; in that case we need busdma to 373 * align to a page boundary so we can send a *contiguous* page size 374 * request to the host. 375 */ 376 if (sc->vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1) 377 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_ALIGN; 378 error = bus_dma_tag_create( 379 bus_get_dma_tag(dev), /* parent */ 380 (sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) ? PAGE_SIZE : 1, 381 0, /* boundary */ 382 BUS_SPACE_MAXADDR, /* lowaddr */ 383 BUS_SPACE_MAXADDR, /* highaddr */ 384 NULL, NULL, /* filter, filterarg */ 385 maxphys, /* max request size */ 386 sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS, /* max # segments */ 387 maxphys, /* maxsegsize */ 388 0, /* flags */ 389 busdma_lock_mutex, /* lockfunc */ 390 &sc->vtblk_mtx, /* lockarg */ 391 &sc->vtblk_dmat); 392 if (error) { 393 device_printf(dev, "cannot create bus dma tag\n"); 394 goto fail; 395 } 396 397 #ifdef __powerpc__ 398 /* 399 * Virtio uses physical addresses rather than bus addresses, so we 400 * need to ask busdma to skip the iommu physical->bus mapping. At 401 * present, this is only a thing on the powerpc architectures. 402 */ 403 bus_dma_tag_set_iommu(sc->vtblk_dmat, NULL, NULL); 404 #endif 405 406 error = vtblk_alloc_virtqueue(sc); 407 if (error) { 408 device_printf(dev, "cannot allocate virtqueue\n"); 409 goto fail; 410 } 411 412 error = vtblk_request_prealloc(sc); 413 if (error) { 414 device_printf(dev, "cannot preallocate requests\n"); 415 goto fail; 416 } 417 418 vtblk_alloc_disk(sc, &blkcfg); 419 420 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 421 if (error) { 422 device_printf(dev, "cannot setup virtqueue interrupt\n"); 423 goto fail; 424 } 425 426 virtqueue_enable_intr(sc->vtblk_vq); 427 428 fail: 429 if (error) 430 vtblk_detach(dev); 431 432 return (error); 433 } 434 435 static int 436 vtblk_detach(device_t dev) 437 { 438 struct vtblk_softc *sc; 439 440 sc = device_get_softc(dev); 441 442 VTBLK_LOCK(sc); 443 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 444 if (device_is_attached(dev)) 445 vtblk_stop(sc); 446 VTBLK_UNLOCK(sc); 447 448 vtblk_drain(sc); 449 450 if (sc->vtblk_disk != NULL) { 451 disk_destroy(sc->vtblk_disk); 452 sc->vtblk_disk = NULL; 453 } 454 455 if (sc->vtblk_dmat != NULL) { 456 bus_dma_tag_destroy(sc->vtblk_dmat); 457 sc->vtblk_dmat = NULL; 458 } 459 460 if (sc->vtblk_sglist != NULL) { 461 sglist_free(sc->vtblk_sglist); 462 sc->vtblk_sglist = NULL; 463 } 464 465 VTBLK_LOCK_DESTROY(sc); 466 467 return (0); 468 } 469 470 static int 471 vtblk_suspend(device_t dev) 472 { 473 struct vtblk_softc *sc; 474 int error; 475 476 sc = device_get_softc(dev); 477 478 VTBLK_LOCK(sc); 479 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 480 /* XXX BMV: virtio_stop(), etc needed here? */ 481 error = vtblk_quiesce(sc); 482 if (error) 483 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 484 VTBLK_UNLOCK(sc); 485 486 return (error); 487 } 488 489 static int 490 vtblk_resume(device_t dev) 491 { 492 struct vtblk_softc *sc; 493 494 sc = device_get_softc(dev); 495 496 VTBLK_LOCK(sc); 497 /* XXX BMV: virtio_reinit(), etc needed here? */ 498 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 499 vtblk_startio(sc); 500 VTBLK_UNLOCK(sc); 501 502 return (0); 503 } 504 505 static int 506 vtblk_shutdown(device_t dev) 507 { 508 509 return (0); 510 } 511 512 static int 513 vtblk_attach_completed(device_t dev) 514 { 515 struct vtblk_softc *sc; 516 517 sc = device_get_softc(dev); 518 519 /* 520 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be 521 * processed after the device acknowledged 522 * VIRTIO_CONFIG_STATUS_DRIVER_OK. 523 */ 524 vtblk_create_disk(sc); 525 return (0); 526 } 527 528 static int 529 vtblk_config_change(device_t dev) 530 { 531 struct vtblk_softc *sc; 532 struct virtio_blk_config blkcfg; 533 uint64_t capacity; 534 535 sc = device_get_softc(dev); 536 537 vtblk_read_config(sc, &blkcfg); 538 539 /* Capacity is always in 512-byte units. */ 540 capacity = blkcfg.capacity * VTBLK_BSIZE; 541 542 if (sc->vtblk_disk->d_mediasize != capacity) 543 vtblk_resize_disk(sc, capacity); 544 545 return (0); 546 } 547 548 static int 549 vtblk_open(struct disk *dp) 550 { 551 struct vtblk_softc *sc; 552 553 if ((sc = dp->d_drv1) == NULL) 554 return (ENXIO); 555 556 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 557 } 558 559 static int 560 vtblk_close(struct disk *dp) 561 { 562 struct vtblk_softc *sc; 563 564 if ((sc = dp->d_drv1) == NULL) 565 return (ENXIO); 566 567 return (0); 568 } 569 570 static int 571 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 572 struct thread *td) 573 { 574 struct vtblk_softc *sc; 575 576 if ((sc = dp->d_drv1) == NULL) 577 return (ENXIO); 578 579 return (ENOTTY); 580 } 581 582 static int 583 vtblk_dump(void *arg, void *virtual, off_t offset, size_t length) 584 { 585 struct disk *dp; 586 struct vtblk_softc *sc; 587 int error; 588 589 dp = arg; 590 error = 0; 591 592 if ((sc = dp->d_drv1) == NULL) 593 return (ENXIO); 594 595 VTBLK_LOCK(sc); 596 597 vtblk_dump_quiesce(sc); 598 599 if (length > 0) 600 error = vtblk_dump_write(sc, virtual, offset, length); 601 if (error || (virtual == NULL && offset == 0)) 602 vtblk_dump_complete(sc); 603 604 VTBLK_UNLOCK(sc); 605 606 return (error); 607 } 608 609 static void 610 vtblk_strategy(struct bio *bp) 611 { 612 struct vtblk_softc *sc; 613 614 if ((sc = bp->bio_disk->d_drv1) == NULL) { 615 vtblk_bio_done(NULL, bp, EINVAL); 616 return; 617 } 618 619 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) && 620 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) { 621 vtblk_bio_done(sc, bp, EOPNOTSUPP); 622 return; 623 } 624 625 VTBLK_LOCK(sc); 626 627 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 628 VTBLK_UNLOCK(sc); 629 vtblk_bio_done(sc, bp, ENXIO); 630 return; 631 } 632 633 bioq_insert_tail(&sc->vtblk_bioq, bp); 634 vtblk_startio(sc); 635 636 VTBLK_UNLOCK(sc); 637 } 638 639 static int 640 vtblk_negotiate_features(struct vtblk_softc *sc) 641 { 642 device_t dev; 643 uint64_t features; 644 645 dev = sc->vtblk_dev; 646 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES : 647 VTBLK_LEGACY_FEATURES; 648 649 sc->vtblk_features = virtio_negotiate_features(dev, features); 650 return (virtio_finalize_features(dev)); 651 } 652 653 static int 654 vtblk_setup_features(struct vtblk_softc *sc) 655 { 656 device_t dev; 657 int error; 658 659 dev = sc->vtblk_dev; 660 661 error = vtblk_negotiate_features(sc); 662 if (error) 663 return (error); 664 665 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 666 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 667 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 668 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG; 669 670 /* Legacy. */ 671 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 672 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 673 674 return (0); 675 } 676 677 static int 678 vtblk_maximum_segments(struct vtblk_softc *sc, 679 struct virtio_blk_config *blkcfg) 680 { 681 device_t dev; 682 int nsegs; 683 684 dev = sc->vtblk_dev; 685 nsegs = VTBLK_MIN_SEGMENTS; 686 687 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 688 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1); 689 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 690 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 691 } else 692 nsegs += 1; 693 694 return (nsegs); 695 } 696 697 static int 698 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 699 { 700 device_t dev; 701 struct vq_alloc_info vq_info; 702 703 dev = sc->vtblk_dev; 704 705 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 706 vtblk_vq_intr, sc, &sc->vtblk_vq, 707 "%s request", device_get_nameunit(dev)); 708 709 return (virtio_alloc_virtqueues(dev, 1, &vq_info)); 710 } 711 712 static void 713 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 714 { 715 device_t dev; 716 struct disk *dp; 717 int error; 718 719 dev = sc->vtblk_dev; 720 dp = sc->vtblk_disk; 721 722 dp->d_mediasize = new_capacity; 723 if (bootverbose) { 724 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 725 (uintmax_t) dp->d_mediasize >> 20, 726 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 727 dp->d_sectorsize); 728 } 729 730 error = disk_resize(dp, M_NOWAIT); 731 if (error) { 732 device_printf(dev, 733 "disk_resize(9) failed, error: %d\n", error); 734 } 735 } 736 737 static void 738 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 739 { 740 device_t dev; 741 struct disk *dp; 742 743 dev = sc->vtblk_dev; 744 745 sc->vtblk_disk = dp = disk_alloc(); 746 dp->d_open = vtblk_open; 747 dp->d_close = vtblk_close; 748 dp->d_ioctl = vtblk_ioctl; 749 dp->d_strategy = vtblk_strategy; 750 dp->d_name = VTBLK_DISK_NAME; 751 dp->d_unit = device_get_unit(dev); 752 dp->d_drv1 = sc; 753 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION; 754 dp->d_hba_vendor = virtio_get_vendor(dev); 755 dp->d_hba_device = virtio_get_device(dev); 756 dp->d_hba_subvendor = virtio_get_subvendor(dev); 757 dp->d_hba_subdevice = virtio_get_subdevice(dev); 758 759 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 760 dp->d_flags |= DISKFLAG_WRITE_PROTECT; 761 else { 762 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 763 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 764 dp->d_dump = vtblk_dump; 765 } 766 767 /* Capacity is always in 512-byte units. */ 768 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE; 769 770 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 771 dp->d_sectorsize = blkcfg->blk_size; 772 else 773 dp->d_sectorsize = VTBLK_BSIZE; 774 775 /* 776 * The VirtIO maximum I/O size is given in terms of segments. 777 * However, FreeBSD limits I/O size by logical buffer size, not 778 * by physically contiguous pages. Therefore, we have to assume 779 * no pages are contiguous. This may impose an artificially low 780 * maximum I/O size. But in practice, since QEMU advertises 128 781 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 782 * which is typically greater than maxphys. Eventually we should 783 * just advertise maxphys and split buffers that are too big. 784 * 785 * If we're not asking busdma to align data to page boundaries, the 786 * maximum I/O size is reduced by PAGE_SIZE in order to accommodate 787 * unaligned I/Os. 788 */ 789 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS) * 790 PAGE_SIZE; 791 if ((sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) == 0) 792 dp->d_maxsize -= PAGE_SIZE; 793 794 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 795 dp->d_fwsectors = blkcfg->geometry.sectors; 796 dp->d_fwheads = blkcfg->geometry.heads; 797 } 798 799 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 800 blkcfg->topology.physical_block_exp > 0) { 801 dp->d_stripesize = dp->d_sectorsize * 802 (1 << blkcfg->topology.physical_block_exp); 803 dp->d_stripeoffset = (dp->d_stripesize - 804 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 805 dp->d_stripesize; 806 } 807 808 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) { 809 dp->d_flags |= DISKFLAG_CANDELETE; 810 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE; 811 } 812 813 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 814 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 815 else 816 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 817 } 818 819 static void 820 vtblk_create_disk(struct vtblk_softc *sc) 821 { 822 struct disk *dp; 823 824 dp = sc->vtblk_disk; 825 826 vtblk_ident(sc); 827 828 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 829 (uintmax_t) dp->d_mediasize >> 20, 830 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 831 dp->d_sectorsize); 832 833 disk_create(dp, DISK_VERSION); 834 } 835 836 static int 837 vtblk_request_prealloc(struct vtblk_softc *sc) 838 { 839 struct vtblk_request *req; 840 int i, nreqs; 841 842 nreqs = virtqueue_size(sc->vtblk_vq); 843 844 /* 845 * Preallocate sufficient requests to keep the virtqueue full. Each 846 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 847 * the number allocated when indirect descriptors are not available. 848 */ 849 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 850 nreqs /= VTBLK_MIN_SEGMENTS; 851 852 for (i = 0; i < nreqs; i++) { 853 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 854 if (req == NULL) 855 return (ENOMEM); 856 857 req->vbr_sc = sc; 858 if (bus_dmamap_create(sc->vtblk_dmat, 0, &req->vbr_mapp)) { 859 free(req, M_DEVBUF); 860 return (ENOMEM); 861 } 862 863 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 864 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 865 866 sc->vtblk_request_count++; 867 vtblk_request_enqueue(sc, req); 868 } 869 870 return (0); 871 } 872 873 static void 874 vtblk_request_free(struct vtblk_softc *sc) 875 { 876 struct vtblk_request *req; 877 878 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 879 880 while ((req = vtblk_request_dequeue(sc)) != NULL) { 881 sc->vtblk_request_count--; 882 bus_dmamap_destroy(sc->vtblk_dmat, req->vbr_mapp); 883 free(req, M_DEVBUF); 884 } 885 886 KASSERT(sc->vtblk_request_count == 0, 887 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 888 } 889 890 static struct vtblk_request * 891 vtblk_request_dequeue(struct vtblk_softc *sc) 892 { 893 struct vtblk_request *req; 894 895 req = TAILQ_FIRST(&sc->vtblk_req_free); 896 if (req != NULL) { 897 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 898 bzero(&req->vbr_hdr, sizeof(struct vtblk_request) - 899 offsetof(struct vtblk_request, vbr_hdr)); 900 } 901 902 return (req); 903 } 904 905 static void 906 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 907 { 908 909 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 910 } 911 912 static struct vtblk_request * 913 vtblk_request_next_ready(struct vtblk_softc *sc) 914 { 915 struct vtblk_request *req; 916 917 req = TAILQ_FIRST(&sc->vtblk_req_ready); 918 if (req != NULL) 919 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 920 921 return (req); 922 } 923 924 static void 925 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 926 { 927 928 /* NOTE: Currently, there will be at most one request in the queue. */ 929 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 930 } 931 932 static struct vtblk_request * 933 vtblk_request_next(struct vtblk_softc *sc) 934 { 935 struct vtblk_request *req; 936 937 req = vtblk_request_next_ready(sc); 938 if (req != NULL) 939 return (req); 940 941 return (vtblk_request_bio(sc)); 942 } 943 944 static struct vtblk_request * 945 vtblk_request_bio(struct vtblk_softc *sc) 946 { 947 struct bio_queue_head *bioq; 948 struct vtblk_request *req; 949 struct bio *bp; 950 951 bioq = &sc->vtblk_bioq; 952 953 if (bioq_first(bioq) == NULL) 954 return (NULL); 955 956 req = vtblk_request_dequeue(sc); 957 if (req == NULL) 958 return (NULL); 959 960 bp = bioq_takefirst(bioq); 961 req->vbr_bp = bp; 962 req->vbr_ack = -1; 963 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 964 965 switch (bp->bio_cmd) { 966 case BIO_FLUSH: 967 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 968 req->vbr_hdr.sector = 0; 969 break; 970 case BIO_READ: 971 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN); 972 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 973 break; 974 case BIO_WRITE: 975 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 976 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 977 break; 978 case BIO_DELETE: 979 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD); 980 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 981 break; 982 default: 983 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 984 } 985 986 if (bp->bio_flags & BIO_ORDERED) 987 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER); 988 989 return (req); 990 } 991 992 static int 993 vtblk_request_execute(struct vtblk_request *req, int flags) 994 { 995 struct vtblk_softc *sc = req->vbr_sc; 996 struct bio *bp = req->vbr_bp; 997 int error = 0; 998 999 /* 1000 * Call via bus_dmamap_load_bio or directly depending on whether we 1001 * have a buffer we need to map. If we don't have a busdma map, 1002 * try to perform the I/O directly and hope that it works (this will 1003 * happen when dumping). 1004 */ 1005 if ((req->vbr_mapp != NULL) && 1006 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) { 1007 error = bus_dmamap_load_bio(sc->vtblk_dmat, req->vbr_mapp, 1008 req->vbr_bp, vtblk_request_execute_cb, req, flags); 1009 if (error == EINPROGRESS) { 1010 req->vbr_busdma_wait = 1; 1011 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_WAIT; 1012 } 1013 } else { 1014 vtblk_request_execute_cb(req, NULL, 0, 0); 1015 } 1016 1017 return (error ? error : req->vbr_error); 1018 } 1019 1020 static void 1021 vtblk_request_execute_cb(void * callback_arg, bus_dma_segment_t * segs, 1022 int nseg, int error) 1023 { 1024 struct vtblk_request *req; 1025 struct vtblk_softc *sc; 1026 struct virtqueue *vq; 1027 struct sglist *sg; 1028 struct bio *bp; 1029 int ordered, readable, writable, i; 1030 1031 req = (struct vtblk_request *)callback_arg; 1032 sc = req->vbr_sc; 1033 vq = sc->vtblk_vq; 1034 sg = sc->vtblk_sglist; 1035 bp = req->vbr_bp; 1036 ordered = 0; 1037 writable = 0; 1038 1039 /* 1040 * If we paused request queueing while we waited for busdma to call us 1041 * asynchronously, unpause it now; this request made it through so we 1042 * don't need to worry about others getting ahead of us. (Note that we 1043 * hold the device mutex so nothing will happen until after we return 1044 * anyway.) 1045 */ 1046 if (req->vbr_busdma_wait) 1047 sc->vtblk_flags &= ~VTBLK_FLAG_BUSDMA_WAIT; 1048 1049 /* Fail on errors from busdma. */ 1050 if (error) 1051 goto out1; 1052 1053 /* 1054 * Some hosts (such as bhyve) do not implement the barrier feature, 1055 * so we emulate it in the driver by allowing the barrier request 1056 * to be the only one in flight. 1057 */ 1058 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 1059 if (sc->vtblk_req_ordered != NULL) { 1060 error = EBUSY; 1061 goto out; 1062 } 1063 if (bp->bio_flags & BIO_ORDERED) { 1064 if (!virtqueue_empty(vq)) { 1065 error = EBUSY; 1066 goto out; 1067 } 1068 ordered = 1; 1069 req->vbr_hdr.type &= vtblk_gtoh32(sc, 1070 ~VIRTIO_BLK_T_BARRIER); 1071 } 1072 } 1073 1074 sglist_reset(sg); 1075 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 1076 1077 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 1078 /* 1079 * We cast bus_addr_t to vm_paddr_t here; since we skip the 1080 * iommu mapping (see vtblk_attach) this should be safe. 1081 */ 1082 for (i = 0; i < nseg; i++) { 1083 error = sglist_append_phys(sg, 1084 (vm_paddr_t)segs[i].ds_addr, segs[i].ds_len); 1085 if (error || sg->sg_nseg == sg->sg_maxseg) { 1086 panic("%s: bio %p data buffer too big %d", 1087 __func__, bp, error); 1088 } 1089 } 1090 1091 /* Special handling for dump, which bypasses busdma. */ 1092 if (req->vbr_mapp == NULL) { 1093 error = sglist_append_bio(sg, bp); 1094 if (error || sg->sg_nseg == sg->sg_maxseg) { 1095 panic("%s: bio %p data buffer too big %d", 1096 __func__, bp, error); 1097 } 1098 } 1099 1100 /* BIO_READ means the host writes into our buffer. */ 1101 if (bp->bio_cmd == BIO_READ) 1102 writable = sg->sg_nseg - 1; 1103 } else if (bp->bio_cmd == BIO_DELETE) { 1104 struct virtio_blk_discard_write_zeroes *discard; 1105 1106 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO); 1107 if (discard == NULL) { 1108 error = ENOMEM; 1109 goto out; 1110 } 1111 1112 bp->bio_driver1 = discard; 1113 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 1114 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE); 1115 error = sglist_append(sg, discard, sizeof(*discard)); 1116 if (error || sg->sg_nseg == sg->sg_maxseg) { 1117 panic("%s: bio %p data buffer too big %d", 1118 __func__, bp, error); 1119 } 1120 } 1121 1122 writable++; 1123 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 1124 readable = sg->sg_nseg - writable; 1125 1126 if (req->vbr_mapp != NULL) { 1127 switch (bp->bio_cmd) { 1128 case BIO_READ: 1129 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1130 BUS_DMASYNC_PREREAD); 1131 break; 1132 case BIO_WRITE: 1133 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1134 BUS_DMASYNC_PREWRITE); 1135 break; 1136 } 1137 } 1138 1139 error = virtqueue_enqueue(vq, req, sg, readable, writable); 1140 if (error == 0 && ordered) 1141 sc->vtblk_req_ordered = req; 1142 1143 /* 1144 * If we were called asynchronously, we need to notify the queue that 1145 * we've added a new request, since the notification from startio was 1146 * performed already. 1147 */ 1148 if (error == 0 && req->vbr_busdma_wait) 1149 virtqueue_notify(vq); 1150 1151 out: 1152 if (error && (req->vbr_mapp != NULL)) 1153 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp); 1154 out1: 1155 if (error && req->vbr_requeue_on_error) 1156 vtblk_request_requeue_ready(sc, req); 1157 req->vbr_error = error; 1158 } 1159 1160 static int 1161 vtblk_request_error(struct vtblk_request *req) 1162 { 1163 int error; 1164 1165 switch (req->vbr_ack) { 1166 case VIRTIO_BLK_S_OK: 1167 error = 0; 1168 break; 1169 case VIRTIO_BLK_S_UNSUPP: 1170 error = ENOTSUP; 1171 break; 1172 default: 1173 error = EIO; 1174 break; 1175 } 1176 1177 return (error); 1178 } 1179 1180 static void 1181 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1182 { 1183 struct vtblk_request *req; 1184 struct bio *bp; 1185 1186 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1187 if (sc->vtblk_req_ordered != NULL) { 1188 MPASS(sc->vtblk_req_ordered == req); 1189 sc->vtblk_req_ordered = NULL; 1190 } 1191 1192 bp = req->vbr_bp; 1193 if (req->vbr_mapp != NULL) { 1194 switch (bp->bio_cmd) { 1195 case BIO_READ: 1196 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1197 BUS_DMASYNC_POSTREAD); 1198 bus_dmamap_unload(sc->vtblk_dmat, 1199 req->vbr_mapp); 1200 break; 1201 case BIO_WRITE: 1202 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1203 BUS_DMASYNC_POSTWRITE); 1204 bus_dmamap_unload(sc->vtblk_dmat, 1205 req->vbr_mapp); 1206 break; 1207 } 1208 } 1209 bp->bio_error = vtblk_request_error(req); 1210 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 1211 1212 vtblk_request_enqueue(sc, req); 1213 } 1214 } 1215 1216 static void 1217 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1218 { 1219 struct bio *bp, *tmp; 1220 1221 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 1222 if (bp->bio_error != 0) 1223 disk_err(bp, "hard error", -1, 1); 1224 vtblk_bio_done(sc, bp, bp->bio_error); 1225 } 1226 } 1227 1228 static void 1229 vtblk_drain_vq(struct vtblk_softc *sc) 1230 { 1231 struct virtqueue *vq; 1232 struct vtblk_request *req; 1233 int last; 1234 1235 vq = sc->vtblk_vq; 1236 last = 0; 1237 1238 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1239 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1240 vtblk_request_enqueue(sc, req); 1241 } 1242 1243 sc->vtblk_req_ordered = NULL; 1244 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1245 } 1246 1247 static void 1248 vtblk_drain(struct vtblk_softc *sc) 1249 { 1250 struct bio_queue_head *bioq; 1251 struct vtblk_request *req; 1252 struct bio *bp; 1253 1254 bioq = &sc->vtblk_bioq; 1255 1256 if (sc->vtblk_vq != NULL) { 1257 struct bio_queue queue; 1258 1259 TAILQ_INIT(&queue); 1260 vtblk_queue_completed(sc, &queue); 1261 vtblk_done_completed(sc, &queue); 1262 1263 vtblk_drain_vq(sc); 1264 } 1265 1266 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1267 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1268 vtblk_request_enqueue(sc, req); 1269 } 1270 1271 while (bioq_first(bioq) != NULL) { 1272 bp = bioq_takefirst(bioq); 1273 vtblk_bio_done(sc, bp, ENXIO); 1274 } 1275 1276 vtblk_request_free(sc); 1277 } 1278 1279 static void 1280 vtblk_startio(struct vtblk_softc *sc) 1281 { 1282 struct virtqueue *vq; 1283 struct vtblk_request *req; 1284 int enq; 1285 1286 VTBLK_LOCK_ASSERT(sc); 1287 vq = sc->vtblk_vq; 1288 enq = 0; 1289 1290 if (sc->vtblk_flags & (VTBLK_FLAG_SUSPEND | VTBLK_FLAG_BUSDMA_WAIT)) 1291 return; 1292 1293 while (!virtqueue_full(vq)) { 1294 req = vtblk_request_next(sc); 1295 if (req == NULL) 1296 break; 1297 1298 req->vbr_requeue_on_error = 1; 1299 if (vtblk_request_execute(req, BUS_DMA_WAITOK)) 1300 break; 1301 1302 enq++; 1303 } 1304 1305 if (enq > 0) 1306 virtqueue_notify(vq); 1307 } 1308 1309 static void 1310 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1311 { 1312 1313 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1314 if (sc != NULL) 1315 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1316 1317 if (error) { 1318 bp->bio_resid = bp->bio_bcount; 1319 bp->bio_error = error; 1320 bp->bio_flags |= BIO_ERROR; 1321 } else { 1322 kmsan_mark_bio(bp, KMSAN_STATE_INITED); 1323 } 1324 1325 if (bp->bio_driver1 != NULL) { 1326 free(bp->bio_driver1, M_DEVBUF); 1327 bp->bio_driver1 = NULL; 1328 } 1329 1330 biodone(bp); 1331 } 1332 1333 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1334 if (virtio_with_feature(_dev, _feature)) { \ 1335 virtio_read_device_config(_dev, \ 1336 offsetof(struct virtio_blk_config, _field), \ 1337 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1338 } 1339 1340 static void 1341 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1342 { 1343 device_t dev; 1344 1345 dev = sc->vtblk_dev; 1346 1347 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1348 1349 /* The capacity is always available. */ 1350 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1351 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1352 1353 /* Read the configuration if the feature was negotiated. */ 1354 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1355 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1356 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1357 geometry.cylinders, blkcfg); 1358 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1359 geometry.heads, blkcfg); 1360 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1361 geometry.sectors, blkcfg); 1362 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1363 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1364 topology.physical_block_exp, blkcfg); 1365 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1366 topology.alignment_offset, blkcfg); 1367 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1368 topology.min_io_size, blkcfg); 1369 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1370 topology.opt_io_size, blkcfg); 1371 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg); 1372 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors, 1373 blkcfg); 1374 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg); 1375 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment, 1376 blkcfg); 1377 } 1378 1379 #undef VTBLK_GET_CONFIG 1380 1381 static void 1382 vtblk_ident(struct vtblk_softc *sc) 1383 { 1384 struct bio buf; 1385 struct disk *dp; 1386 struct vtblk_request *req; 1387 int len, error; 1388 1389 dp = sc->vtblk_disk; 1390 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1391 1392 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1393 return; 1394 1395 req = vtblk_request_dequeue(sc); 1396 if (req == NULL) 1397 return; 1398 1399 req->vbr_ack = -1; 1400 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID); 1401 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1402 req->vbr_hdr.sector = 0; 1403 1404 req->vbr_bp = &buf; 1405 g_reset_bio(&buf); 1406 1407 buf.bio_cmd = BIO_READ; 1408 buf.bio_data = dp->d_ident; 1409 buf.bio_bcount = len; 1410 1411 VTBLK_LOCK(sc); 1412 error = vtblk_poll_request(sc, req); 1413 VTBLK_UNLOCK(sc); 1414 1415 vtblk_request_enqueue(sc, req); 1416 1417 if (error) { 1418 device_printf(sc->vtblk_dev, 1419 "error getting device identifier: %d\n", error); 1420 } 1421 } 1422 1423 static int 1424 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1425 { 1426 struct virtqueue *vq; 1427 int error; 1428 1429 vq = sc->vtblk_vq; 1430 1431 if (!virtqueue_empty(vq)) 1432 return (EBUSY); 1433 1434 error = vtblk_request_execute(req, BUS_DMA_NOWAIT); 1435 if (error) 1436 return (error); 1437 1438 virtqueue_notify(vq); 1439 virtqueue_poll(vq, NULL); 1440 1441 error = vtblk_request_error(req); 1442 if (error && bootverbose) { 1443 device_printf(sc->vtblk_dev, 1444 "%s: IO error: %d\n", __func__, error); 1445 } 1446 1447 return (error); 1448 } 1449 1450 static int 1451 vtblk_quiesce(struct vtblk_softc *sc) 1452 { 1453 int error; 1454 1455 VTBLK_LOCK_ASSERT(sc); 1456 error = 0; 1457 1458 while (!virtqueue_empty(sc->vtblk_vq)) { 1459 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1460 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1461 error = EBUSY; 1462 break; 1463 } 1464 } 1465 1466 return (error); 1467 } 1468 1469 static void 1470 vtblk_vq_intr(void *xsc) 1471 { 1472 struct vtblk_softc *sc; 1473 struct virtqueue *vq; 1474 struct bio_queue queue; 1475 1476 sc = xsc; 1477 vq = sc->vtblk_vq; 1478 TAILQ_INIT(&queue); 1479 1480 VTBLK_LOCK(sc); 1481 1482 again: 1483 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1484 goto out; 1485 1486 vtblk_queue_completed(sc, &queue); 1487 vtblk_startio(sc); 1488 1489 if (virtqueue_enable_intr(vq) != 0) { 1490 virtqueue_disable_intr(vq); 1491 goto again; 1492 } 1493 1494 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1495 wakeup(&sc->vtblk_vq); 1496 1497 out: 1498 VTBLK_UNLOCK(sc); 1499 vtblk_done_completed(sc, &queue); 1500 } 1501 1502 static void 1503 vtblk_stop(struct vtblk_softc *sc) 1504 { 1505 1506 virtqueue_disable_intr(sc->vtblk_vq); 1507 virtio_stop(sc->vtblk_dev); 1508 } 1509 1510 static void 1511 vtblk_dump_quiesce(struct vtblk_softc *sc) 1512 { 1513 1514 /* 1515 * Spin here until all the requests in-flight at the time of the 1516 * dump are completed and queued. The queued requests will be 1517 * biodone'd once the dump is finished. 1518 */ 1519 while (!virtqueue_empty(sc->vtblk_vq)) 1520 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1521 } 1522 1523 static int 1524 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1525 size_t length) 1526 { 1527 struct bio buf; 1528 struct vtblk_request *req; 1529 1530 req = &sc->vtblk_dump_request; 1531 req->vbr_sc = sc; 1532 req->vbr_ack = -1; 1533 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 1534 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1535 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE); 1536 1537 req->vbr_bp = &buf; 1538 g_reset_bio(&buf); 1539 1540 buf.bio_cmd = BIO_WRITE; 1541 buf.bio_data = virtual; 1542 buf.bio_bcount = length; 1543 1544 return (vtblk_poll_request(sc, req)); 1545 } 1546 1547 static int 1548 vtblk_dump_flush(struct vtblk_softc *sc) 1549 { 1550 struct bio buf; 1551 struct vtblk_request *req; 1552 1553 req = &sc->vtblk_dump_request; 1554 req->vbr_sc = sc; 1555 req->vbr_ack = -1; 1556 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 1557 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1558 req->vbr_hdr.sector = 0; 1559 1560 req->vbr_bp = &buf; 1561 g_reset_bio(&buf); 1562 1563 buf.bio_cmd = BIO_FLUSH; 1564 1565 return (vtblk_poll_request(sc, req)); 1566 } 1567 1568 static void 1569 vtblk_dump_complete(struct vtblk_softc *sc) 1570 { 1571 1572 vtblk_dump_flush(sc); 1573 1574 VTBLK_UNLOCK(sc); 1575 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1576 VTBLK_LOCK(sc); 1577 } 1578 1579 static void 1580 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1581 { 1582 1583 /* Set either writeback (1) or writethrough (0) mode. */ 1584 virtio_write_dev_config_1(sc->vtblk_dev, 1585 offsetof(struct virtio_blk_config, wce), wc); 1586 } 1587 1588 static int 1589 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1590 struct virtio_blk_config *blkcfg) 1591 { 1592 int wc; 1593 1594 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) { 1595 wc = vtblk_tunable_int(sc, "writecache_mode", 1596 vtblk_writecache_mode); 1597 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1598 vtblk_set_write_cache(sc, wc); 1599 else 1600 wc = blkcfg->wce; 1601 } else 1602 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH); 1603 1604 return (wc); 1605 } 1606 1607 static int 1608 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1609 { 1610 struct vtblk_softc *sc; 1611 int wc, error; 1612 1613 sc = oidp->oid_arg1; 1614 wc = sc->vtblk_write_cache; 1615 1616 error = sysctl_handle_int(oidp, &wc, 0, req); 1617 if (error || req->newptr == NULL) 1618 return (error); 1619 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0) 1620 return (EPERM); 1621 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1622 return (EINVAL); 1623 1624 VTBLK_LOCK(sc); 1625 sc->vtblk_write_cache = wc; 1626 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1627 VTBLK_UNLOCK(sc); 1628 1629 return (0); 1630 } 1631 1632 static void 1633 vtblk_setup_sysctl(struct vtblk_softc *sc) 1634 { 1635 device_t dev; 1636 struct sysctl_ctx_list *ctx; 1637 struct sysctl_oid *tree; 1638 struct sysctl_oid_list *child; 1639 1640 dev = sc->vtblk_dev; 1641 ctx = device_get_sysctl_ctx(dev); 1642 tree = device_get_sysctl_tree(dev); 1643 child = SYSCTL_CHILDREN(tree); 1644 1645 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1646 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0, 1647 vtblk_write_cache_sysctl, "I", 1648 "Write cache mode (writethrough (0) or writeback (1))"); 1649 } 1650 1651 static int 1652 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1653 { 1654 char path[64]; 1655 1656 snprintf(path, sizeof(path), 1657 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1658 TUNABLE_INT_FETCH(path, &def); 1659 1660 return (def); 1661 } 1662