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 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/bio.h> 36 #include <sys/malloc.h> 37 #include <sys/module.h> 38 #include <sys/msan.h> 39 #include <sys/sglist.h> 40 #include <sys/sysctl.h> 41 #include <sys/lock.h> 42 #include <sys/mutex.h> 43 #include <sys/queue.h> 44 45 #include <geom/geom.h> 46 #include <geom/geom_disk.h> 47 48 #include <machine/bus.h> 49 #include <machine/resource.h> 50 #include <sys/bus.h> 51 #include <sys/rman.h> 52 53 #include <dev/virtio/virtio.h> 54 #include <dev/virtio/virtqueue.h> 55 #include <dev/virtio/block/virtio_blk.h> 56 57 #include "virtio_if.h" 58 59 struct vtblk_request { 60 struct vtblk_softc *vbr_sc; 61 bus_dmamap_t vbr_mapp; 62 63 /* Fields after this point are zeroed for each request. */ 64 struct virtio_blk_outhdr vbr_hdr; 65 struct bio *vbr_bp; 66 uint8_t vbr_ack; 67 uint8_t vbr_requeue_on_error; 68 uint8_t vbr_busdma_wait; 69 int vbr_error; 70 TAILQ_ENTRY(vtblk_request) vbr_link; 71 }; 72 73 enum vtblk_cache_mode { 74 VTBLK_CACHE_WRITETHROUGH, 75 VTBLK_CACHE_WRITEBACK, 76 VTBLK_CACHE_MAX 77 }; 78 79 struct vtblk_softc { 80 device_t vtblk_dev; 81 struct mtx vtblk_mtx; 82 uint64_t vtblk_features; 83 uint32_t vtblk_flags; 84 #define VTBLK_FLAG_INDIRECT 0x0001 85 #define VTBLK_FLAG_DETACH 0x0002 86 #define VTBLK_FLAG_SUSPEND 0x0004 87 #define VTBLK_FLAG_BARRIER 0x0008 88 #define VTBLK_FLAG_WCE_CONFIG 0x0010 89 #define VTBLK_FLAG_BUSDMA_WAIT 0x0020 90 #define VTBLK_FLAG_BUSDMA_ALIGN 0x0040 91 92 struct virtqueue *vtblk_vq; 93 struct sglist *vtblk_sglist; 94 bus_dma_tag_t vtblk_dmat; 95 struct disk *vtblk_disk; 96 97 struct bio_queue_head vtblk_bioq; 98 TAILQ_HEAD(, vtblk_request) 99 vtblk_req_free; 100 TAILQ_HEAD(, vtblk_request) 101 vtblk_req_ready; 102 struct vtblk_request *vtblk_req_ordered; 103 104 int vtblk_max_nsegs; 105 int vtblk_request_count; 106 enum vtblk_cache_mode vtblk_write_cache; 107 108 struct bio_queue vtblk_dump_queue; 109 struct vtblk_request vtblk_dump_request; 110 }; 111 112 static struct virtio_feature_desc vtblk_feature_desc[] = { 113 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 114 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 115 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 116 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 117 { VIRTIO_BLK_F_RO, "ReadOnly" }, 118 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 119 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 120 { VIRTIO_BLK_F_FLUSH, "FlushCmd" }, 121 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 122 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, 123 { VIRTIO_BLK_F_MQ, "Multiqueue" }, 124 { VIRTIO_BLK_F_DISCARD, "Discard" }, 125 { VIRTIO_BLK_F_WRITE_ZEROES, "WriteZeros" }, 126 127 { 0, NULL } 128 }; 129 130 static int vtblk_modevent(module_t, int, void *); 131 132 static int vtblk_probe(device_t); 133 static int vtblk_attach(device_t); 134 static int vtblk_detach(device_t); 135 static int vtblk_suspend(device_t); 136 static int vtblk_resume(device_t); 137 static int vtblk_shutdown(device_t); 138 static int vtblk_attach_completed(device_t); 139 static int vtblk_config_change(device_t); 140 141 static int vtblk_open(struct disk *); 142 static int vtblk_close(struct disk *); 143 static int vtblk_ioctl(struct disk *, u_long, void *, int, 144 struct thread *); 145 static int vtblk_dump(void *, void *, off_t, size_t); 146 static void vtblk_strategy(struct bio *); 147 148 static int vtblk_negotiate_features(struct vtblk_softc *); 149 static int vtblk_setup_features(struct vtblk_softc *); 150 static int vtblk_maximum_segments(struct vtblk_softc *, 151 struct virtio_blk_config *); 152 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 153 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 154 static void vtblk_alloc_disk(struct vtblk_softc *, 155 struct virtio_blk_config *); 156 static void vtblk_create_disk(struct vtblk_softc *); 157 158 static int vtblk_request_prealloc(struct vtblk_softc *); 159 static void vtblk_request_free(struct vtblk_softc *); 160 static struct vtblk_request * 161 vtblk_request_dequeue(struct vtblk_softc *); 162 static void vtblk_request_enqueue(struct vtblk_softc *, 163 struct vtblk_request *); 164 static struct vtblk_request * 165 vtblk_request_next_ready(struct vtblk_softc *); 166 static void vtblk_request_requeue_ready(struct vtblk_softc *, 167 struct vtblk_request *); 168 static struct vtblk_request * 169 vtblk_request_next(struct vtblk_softc *); 170 static struct vtblk_request * 171 vtblk_request_bio(struct vtblk_softc *); 172 static int vtblk_request_execute(struct vtblk_request *, int); 173 static void vtblk_request_execute_cb(void *, 174 bus_dma_segment_t *, int, int); 175 static int vtblk_request_error(struct vtblk_request *); 176 177 static void vtblk_queue_completed(struct vtblk_softc *, 178 struct bio_queue *); 179 static void vtblk_done_completed(struct vtblk_softc *, 180 struct bio_queue *); 181 static void vtblk_drain_vq(struct vtblk_softc *); 182 static void vtblk_drain(struct vtblk_softc *); 183 184 static void vtblk_startio(struct vtblk_softc *); 185 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 186 187 static void vtblk_read_config(struct vtblk_softc *, 188 struct virtio_blk_config *); 189 static void vtblk_ident(struct vtblk_softc *); 190 static int vtblk_poll_request(struct vtblk_softc *, 191 struct vtblk_request *); 192 static int vtblk_quiesce(struct vtblk_softc *); 193 static void vtblk_vq_intr(void *); 194 static void vtblk_stop(struct vtblk_softc *); 195 196 static void vtblk_dump_quiesce(struct vtblk_softc *); 197 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 198 static int vtblk_dump_flush(struct vtblk_softc *); 199 static void vtblk_dump_complete(struct vtblk_softc *); 200 201 static void vtblk_set_write_cache(struct vtblk_softc *, int); 202 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 203 struct virtio_blk_config *); 204 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 205 206 static void vtblk_setup_sysctl(struct vtblk_softc *); 207 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 208 209 #define vtblk_modern(_sc) (((_sc)->vtblk_features & VIRTIO_F_VERSION_1) != 0) 210 #define vtblk_htog16(_sc, _val) virtio_htog16(vtblk_modern(_sc), _val) 211 #define vtblk_htog32(_sc, _val) virtio_htog32(vtblk_modern(_sc), _val) 212 #define vtblk_htog64(_sc, _val) virtio_htog64(vtblk_modern(_sc), _val) 213 #define vtblk_gtoh16(_sc, _val) virtio_gtoh16(vtblk_modern(_sc), _val) 214 #define vtblk_gtoh32(_sc, _val) virtio_gtoh32(vtblk_modern(_sc), _val) 215 #define vtblk_gtoh64(_sc, _val) virtio_gtoh64(vtblk_modern(_sc), _val) 216 217 /* Tunables. */ 218 static int vtblk_no_ident = 0; 219 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 220 static int vtblk_writecache_mode = -1; 221 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 222 223 #define VTBLK_COMMON_FEATURES \ 224 (VIRTIO_BLK_F_SIZE_MAX | \ 225 VIRTIO_BLK_F_SEG_MAX | \ 226 VIRTIO_BLK_F_GEOMETRY | \ 227 VIRTIO_BLK_F_RO | \ 228 VIRTIO_BLK_F_BLK_SIZE | \ 229 VIRTIO_BLK_F_FLUSH | \ 230 VIRTIO_BLK_F_TOPOLOGY | \ 231 VIRTIO_BLK_F_CONFIG_WCE | \ 232 VIRTIO_BLK_F_DISCARD | \ 233 VIRTIO_RING_F_INDIRECT_DESC) 234 235 #define VTBLK_MODERN_FEATURES (VTBLK_COMMON_FEATURES) 236 #define VTBLK_LEGACY_FEATURES (VIRTIO_BLK_F_BARRIER | VTBLK_COMMON_FEATURES) 237 238 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 239 #define VTBLK_LOCK_INIT(_sc, _name) \ 240 mtx_init(VTBLK_MTX((_sc)), (_name), \ 241 "VirtIO Block Lock", MTX_DEF) 242 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 243 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 244 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 245 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 246 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 247 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 248 249 #define VTBLK_DISK_NAME "vtbd" 250 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 251 #define VTBLK_BSIZE 512 252 253 /* 254 * Each block request uses at least two segments - one for the header 255 * and one for the status. 256 */ 257 #define VTBLK_MIN_SEGMENTS 2 258 259 static device_method_t vtblk_methods[] = { 260 /* Device methods. */ 261 DEVMETHOD(device_probe, vtblk_probe), 262 DEVMETHOD(device_attach, vtblk_attach), 263 DEVMETHOD(device_detach, vtblk_detach), 264 DEVMETHOD(device_suspend, vtblk_suspend), 265 DEVMETHOD(device_resume, vtblk_resume), 266 DEVMETHOD(device_shutdown, vtblk_shutdown), 267 268 /* VirtIO methods. */ 269 DEVMETHOD(virtio_attach_completed, vtblk_attach_completed), 270 DEVMETHOD(virtio_config_change, vtblk_config_change), 271 272 DEVMETHOD_END 273 }; 274 275 static driver_t vtblk_driver = { 276 "vtblk", 277 vtblk_methods, 278 sizeof(struct vtblk_softc) 279 }; 280 281 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_modevent, NULL); 282 MODULE_VERSION(virtio_blk, 1); 283 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 284 285 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter"); 286 287 static int 288 vtblk_modevent(module_t mod, int type, void *unused) 289 { 290 int error; 291 292 error = 0; 293 294 switch (type) { 295 case MOD_LOAD: 296 case MOD_QUIESCE: 297 case MOD_UNLOAD: 298 case MOD_SHUTDOWN: 299 break; 300 default: 301 error = EOPNOTSUPP; 302 break; 303 } 304 305 return (error); 306 } 307 308 static int 309 vtblk_probe(device_t dev) 310 { 311 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk)); 312 } 313 314 static int 315 vtblk_attach(device_t dev) 316 { 317 struct vtblk_softc *sc; 318 struct virtio_blk_config blkcfg; 319 int error; 320 321 sc = device_get_softc(dev); 322 sc->vtblk_dev = dev; 323 virtio_set_feature_desc(dev, vtblk_feature_desc); 324 325 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 326 bioq_init(&sc->vtblk_bioq); 327 TAILQ_INIT(&sc->vtblk_dump_queue); 328 TAILQ_INIT(&sc->vtblk_req_free); 329 TAILQ_INIT(&sc->vtblk_req_ready); 330 331 vtblk_setup_sysctl(sc); 332 333 error = vtblk_setup_features(sc); 334 if (error) { 335 device_printf(dev, "cannot setup features\n"); 336 goto fail; 337 } 338 339 vtblk_read_config(sc, &blkcfg); 340 341 /* 342 * With the current sglist(9) implementation, it is not easy 343 * for us to support a maximum segment size as adjacent 344 * segments are coalesced. For now, just make sure it's larger 345 * than the maximum supported transfer size. 346 */ 347 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 348 if (blkcfg.size_max < maxphys) { 349 error = ENOTSUP; 350 device_printf(dev, "host requires unsupported " 351 "maximum segment size feature\n"); 352 goto fail; 353 } 354 } 355 356 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 357 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 358 error = EINVAL; 359 device_printf(dev, "fewer than minimum number of segments " 360 "allowed: %d\n", sc->vtblk_max_nsegs); 361 goto fail; 362 } 363 364 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 365 if (sc->vtblk_sglist == NULL) { 366 error = ENOMEM; 367 device_printf(dev, "cannot allocate sglist\n"); 368 goto fail; 369 } 370 371 /* 372 * If vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1, the device only 373 * supports a single data segment; in that case we need busdma to 374 * align to a page boundary so we can send a *contiguous* page size 375 * request to the host. 376 */ 377 if (sc->vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1) 378 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_ALIGN; 379 error = bus_dma_tag_create( 380 bus_get_dma_tag(dev), /* parent */ 381 (sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) ? PAGE_SIZE : 1, 382 0, /* boundary */ 383 BUS_SPACE_MAXADDR, /* lowaddr */ 384 BUS_SPACE_MAXADDR, /* highaddr */ 385 NULL, NULL, /* filter, filterarg */ 386 maxphys, /* max request size */ 387 sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS, /* max # segments */ 388 maxphys, /* maxsegsize */ 389 0, /* flags */ 390 busdma_lock_mutex, /* lockfunc */ 391 &sc->vtblk_mtx, /* lockarg */ 392 &sc->vtblk_dmat); 393 if (error) { 394 device_printf(dev, "cannot create bus dma tag\n"); 395 goto fail; 396 } 397 398 #ifdef __powerpc__ 399 /* 400 * Virtio uses physical addresses rather than bus addresses, so we 401 * need to ask busdma to skip the iommu physical->bus mapping. At 402 * present, this is only a thing on the powerpc architectures. 403 */ 404 bus_dma_tag_set_iommu(sc->vtblk_dmat, NULL, NULL); 405 #endif 406 407 error = vtblk_alloc_virtqueue(sc); 408 if (error) { 409 device_printf(dev, "cannot allocate virtqueue\n"); 410 goto fail; 411 } 412 413 error = vtblk_request_prealloc(sc); 414 if (error) { 415 device_printf(dev, "cannot preallocate requests\n"); 416 goto fail; 417 } 418 419 vtblk_alloc_disk(sc, &blkcfg); 420 421 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 422 if (error) { 423 device_printf(dev, "cannot setup virtqueue interrupt\n"); 424 goto fail; 425 } 426 427 virtqueue_enable_intr(sc->vtblk_vq); 428 429 fail: 430 if (error) 431 vtblk_detach(dev); 432 433 return (error); 434 } 435 436 static int 437 vtblk_detach(device_t dev) 438 { 439 struct vtblk_softc *sc; 440 441 sc = device_get_softc(dev); 442 443 VTBLK_LOCK(sc); 444 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 445 if (device_is_attached(dev)) 446 vtblk_stop(sc); 447 VTBLK_UNLOCK(sc); 448 449 vtblk_drain(sc); 450 451 if (sc->vtblk_disk != NULL) { 452 disk_destroy(sc->vtblk_disk); 453 sc->vtblk_disk = NULL; 454 } 455 456 if (sc->vtblk_dmat != NULL) { 457 bus_dma_tag_destroy(sc->vtblk_dmat); 458 sc->vtblk_dmat = NULL; 459 } 460 461 if (sc->vtblk_sglist != NULL) { 462 sglist_free(sc->vtblk_sglist); 463 sc->vtblk_sglist = NULL; 464 } 465 466 VTBLK_LOCK_DESTROY(sc); 467 468 return (0); 469 } 470 471 static int 472 vtblk_suspend(device_t dev) 473 { 474 struct vtblk_softc *sc; 475 int error; 476 477 sc = device_get_softc(dev); 478 479 VTBLK_LOCK(sc); 480 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 481 /* XXX BMV: virtio_stop(), etc needed here? */ 482 error = vtblk_quiesce(sc); 483 if (error) 484 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 485 VTBLK_UNLOCK(sc); 486 487 return (error); 488 } 489 490 static int 491 vtblk_resume(device_t dev) 492 { 493 struct vtblk_softc *sc; 494 495 sc = device_get_softc(dev); 496 497 VTBLK_LOCK(sc); 498 /* XXX BMV: virtio_reinit(), etc needed here? */ 499 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 500 vtblk_startio(sc); 501 VTBLK_UNLOCK(sc); 502 503 return (0); 504 } 505 506 static int 507 vtblk_shutdown(device_t dev) 508 { 509 510 return (0); 511 } 512 513 static int 514 vtblk_attach_completed(device_t dev) 515 { 516 struct vtblk_softc *sc; 517 518 sc = device_get_softc(dev); 519 520 /* 521 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be 522 * processed after the device acknowledged 523 * VIRTIO_CONFIG_STATUS_DRIVER_OK. 524 */ 525 vtblk_create_disk(sc); 526 return (0); 527 } 528 529 static int 530 vtblk_config_change(device_t dev) 531 { 532 struct vtblk_softc *sc; 533 struct virtio_blk_config blkcfg; 534 uint64_t capacity; 535 536 sc = device_get_softc(dev); 537 538 vtblk_read_config(sc, &blkcfg); 539 540 /* Capacity is always in 512-byte units. */ 541 capacity = blkcfg.capacity * VTBLK_BSIZE; 542 543 if (sc->vtblk_disk->d_mediasize != capacity) 544 vtblk_resize_disk(sc, capacity); 545 546 return (0); 547 } 548 549 static int 550 vtblk_open(struct disk *dp) 551 { 552 struct vtblk_softc *sc; 553 554 if ((sc = dp->d_drv1) == NULL) 555 return (ENXIO); 556 557 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 558 } 559 560 static int 561 vtblk_close(struct disk *dp) 562 { 563 struct vtblk_softc *sc; 564 565 if ((sc = dp->d_drv1) == NULL) 566 return (ENXIO); 567 568 return (0); 569 } 570 571 static int 572 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 573 struct thread *td) 574 { 575 struct vtblk_softc *sc; 576 577 if ((sc = dp->d_drv1) == NULL) 578 return (ENXIO); 579 580 return (ENOTTY); 581 } 582 583 static int 584 vtblk_dump(void *arg, void *virtual, off_t offset, size_t length) 585 { 586 struct disk *dp; 587 struct vtblk_softc *sc; 588 int error; 589 590 dp = arg; 591 error = 0; 592 593 if ((sc = dp->d_drv1) == NULL) 594 return (ENXIO); 595 596 VTBLK_LOCK(sc); 597 598 vtblk_dump_quiesce(sc); 599 600 if (length > 0) 601 error = vtblk_dump_write(sc, virtual, offset, length); 602 if (error || (virtual == NULL && offset == 0)) 603 vtblk_dump_complete(sc); 604 605 VTBLK_UNLOCK(sc); 606 607 return (error); 608 } 609 610 static void 611 vtblk_strategy(struct bio *bp) 612 { 613 struct vtblk_softc *sc; 614 615 if ((sc = bp->bio_disk->d_drv1) == NULL) { 616 vtblk_bio_done(NULL, bp, EINVAL); 617 return; 618 } 619 620 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) && 621 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) { 622 vtblk_bio_done(sc, bp, EOPNOTSUPP); 623 return; 624 } 625 626 VTBLK_LOCK(sc); 627 628 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 629 VTBLK_UNLOCK(sc); 630 vtblk_bio_done(sc, bp, ENXIO); 631 return; 632 } 633 634 bioq_insert_tail(&sc->vtblk_bioq, bp); 635 vtblk_startio(sc); 636 637 VTBLK_UNLOCK(sc); 638 } 639 640 static int 641 vtblk_negotiate_features(struct vtblk_softc *sc) 642 { 643 device_t dev; 644 uint64_t features; 645 646 dev = sc->vtblk_dev; 647 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES : 648 VTBLK_LEGACY_FEATURES; 649 650 sc->vtblk_features = virtio_negotiate_features(dev, features); 651 return (virtio_finalize_features(dev)); 652 } 653 654 static int 655 vtblk_setup_features(struct vtblk_softc *sc) 656 { 657 device_t dev; 658 int error; 659 660 dev = sc->vtblk_dev; 661 662 error = vtblk_negotiate_features(sc); 663 if (error) 664 return (error); 665 666 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 667 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 668 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 669 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG; 670 671 /* Legacy. */ 672 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 673 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 674 675 return (0); 676 } 677 678 static int 679 vtblk_maximum_segments(struct vtblk_softc *sc, 680 struct virtio_blk_config *blkcfg) 681 { 682 device_t dev; 683 int nsegs; 684 685 dev = sc->vtblk_dev; 686 nsegs = VTBLK_MIN_SEGMENTS; 687 688 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 689 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1); 690 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 691 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 692 } else 693 nsegs += 1; 694 695 return (nsegs); 696 } 697 698 static int 699 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 700 { 701 device_t dev; 702 struct vq_alloc_info vq_info; 703 704 dev = sc->vtblk_dev; 705 706 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 707 vtblk_vq_intr, sc, &sc->vtblk_vq, 708 "%s request", device_get_nameunit(dev)); 709 710 return (virtio_alloc_virtqueues(dev, 1, &vq_info)); 711 } 712 713 static void 714 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 715 { 716 device_t dev; 717 struct disk *dp; 718 int error; 719 720 dev = sc->vtblk_dev; 721 dp = sc->vtblk_disk; 722 723 dp->d_mediasize = new_capacity; 724 if (bootverbose) { 725 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 726 (uintmax_t) dp->d_mediasize >> 20, 727 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 728 dp->d_sectorsize); 729 } 730 731 error = disk_resize(dp, M_NOWAIT); 732 if (error) { 733 device_printf(dev, 734 "disk_resize(9) failed, error: %d\n", error); 735 } 736 } 737 738 static void 739 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 740 { 741 device_t dev; 742 struct disk *dp; 743 744 dev = sc->vtblk_dev; 745 746 sc->vtblk_disk = dp = disk_alloc(); 747 dp->d_open = vtblk_open; 748 dp->d_close = vtblk_close; 749 dp->d_ioctl = vtblk_ioctl; 750 dp->d_strategy = vtblk_strategy; 751 dp->d_name = VTBLK_DISK_NAME; 752 dp->d_unit = device_get_unit(dev); 753 dp->d_drv1 = sc; 754 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION; 755 dp->d_hba_vendor = virtio_get_vendor(dev); 756 dp->d_hba_device = virtio_get_device(dev); 757 dp->d_hba_subvendor = virtio_get_subvendor(dev); 758 dp->d_hba_subdevice = virtio_get_subdevice(dev); 759 760 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 761 dp->d_flags |= DISKFLAG_WRITE_PROTECT; 762 else { 763 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 764 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 765 dp->d_dump = vtblk_dump; 766 } 767 768 /* Capacity is always in 512-byte units. */ 769 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE; 770 771 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 772 dp->d_sectorsize = blkcfg->blk_size; 773 else 774 dp->d_sectorsize = VTBLK_BSIZE; 775 776 /* 777 * The VirtIO maximum I/O size is given in terms of segments. 778 * However, FreeBSD limits I/O size by logical buffer size, not 779 * by physically contiguous pages. Therefore, we have to assume 780 * no pages are contiguous. This may impose an artificially low 781 * maximum I/O size. But in practice, since QEMU advertises 128 782 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 783 * which is typically greater than maxphys. Eventually we should 784 * just advertise maxphys and split buffers that are too big. 785 * 786 * If we're not asking busdma to align data to page boundaries, the 787 * maximum I/O size is reduced by PAGE_SIZE in order to accommodate 788 * unaligned I/Os. 789 */ 790 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS) * 791 PAGE_SIZE; 792 if ((sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) == 0) 793 dp->d_maxsize -= PAGE_SIZE; 794 795 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 796 dp->d_fwsectors = blkcfg->geometry.sectors; 797 dp->d_fwheads = blkcfg->geometry.heads; 798 } 799 800 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 801 blkcfg->topology.physical_block_exp > 0) { 802 dp->d_stripesize = dp->d_sectorsize * 803 (1 << blkcfg->topology.physical_block_exp); 804 dp->d_stripeoffset = (dp->d_stripesize - 805 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 806 dp->d_stripesize; 807 } 808 809 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) { 810 dp->d_flags |= DISKFLAG_CANDELETE; 811 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE; 812 } 813 814 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 815 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 816 else 817 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 818 } 819 820 static void 821 vtblk_create_disk(struct vtblk_softc *sc) 822 { 823 struct disk *dp; 824 825 dp = sc->vtblk_disk; 826 827 vtblk_ident(sc); 828 829 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 830 (uintmax_t) dp->d_mediasize >> 20, 831 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 832 dp->d_sectorsize); 833 834 disk_create(dp, DISK_VERSION); 835 } 836 837 static int 838 vtblk_request_prealloc(struct vtblk_softc *sc) 839 { 840 struct vtblk_request *req; 841 int i, nreqs; 842 843 nreqs = virtqueue_size(sc->vtblk_vq); 844 845 /* 846 * Preallocate sufficient requests to keep the virtqueue full. Each 847 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 848 * the number allocated when indirect descriptors are not available. 849 */ 850 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 851 nreqs /= VTBLK_MIN_SEGMENTS; 852 853 for (i = 0; i < nreqs; i++) { 854 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 855 if (req == NULL) 856 return (ENOMEM); 857 858 req->vbr_sc = sc; 859 if (bus_dmamap_create(sc->vtblk_dmat, 0, &req->vbr_mapp)) { 860 free(req, M_DEVBUF); 861 return (ENOMEM); 862 } 863 864 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 865 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 866 867 sc->vtblk_request_count++; 868 vtblk_request_enqueue(sc, req); 869 } 870 871 return (0); 872 } 873 874 static void 875 vtblk_request_free(struct vtblk_softc *sc) 876 { 877 struct vtblk_request *req; 878 879 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 880 881 while ((req = vtblk_request_dequeue(sc)) != NULL) { 882 sc->vtblk_request_count--; 883 bus_dmamap_destroy(sc->vtblk_dmat, req->vbr_mapp); 884 free(req, M_DEVBUF); 885 } 886 887 KASSERT(sc->vtblk_request_count == 0, 888 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 889 } 890 891 static struct vtblk_request * 892 vtblk_request_dequeue(struct vtblk_softc *sc) 893 { 894 struct vtblk_request *req; 895 896 req = TAILQ_FIRST(&sc->vtblk_req_free); 897 if (req != NULL) { 898 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 899 bzero(&req->vbr_hdr, sizeof(struct vtblk_request) - 900 offsetof(struct vtblk_request, vbr_hdr)); 901 } 902 903 return (req); 904 } 905 906 static void 907 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 908 { 909 910 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 911 } 912 913 static struct vtblk_request * 914 vtblk_request_next_ready(struct vtblk_softc *sc) 915 { 916 struct vtblk_request *req; 917 918 req = TAILQ_FIRST(&sc->vtblk_req_ready); 919 if (req != NULL) 920 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 921 922 return (req); 923 } 924 925 static void 926 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 927 { 928 929 /* NOTE: Currently, there will be at most one request in the queue. */ 930 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 931 } 932 933 static struct vtblk_request * 934 vtblk_request_next(struct vtblk_softc *sc) 935 { 936 struct vtblk_request *req; 937 938 req = vtblk_request_next_ready(sc); 939 if (req != NULL) 940 return (req); 941 942 return (vtblk_request_bio(sc)); 943 } 944 945 static struct vtblk_request * 946 vtblk_request_bio(struct vtblk_softc *sc) 947 { 948 struct bio_queue_head *bioq; 949 struct vtblk_request *req; 950 struct bio *bp; 951 952 bioq = &sc->vtblk_bioq; 953 954 if (bioq_first(bioq) == NULL) 955 return (NULL); 956 957 req = vtblk_request_dequeue(sc); 958 if (req == NULL) 959 return (NULL); 960 961 bp = bioq_takefirst(bioq); 962 req->vbr_bp = bp; 963 req->vbr_ack = -1; 964 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 965 966 switch (bp->bio_cmd) { 967 case BIO_FLUSH: 968 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 969 req->vbr_hdr.sector = 0; 970 break; 971 case BIO_READ: 972 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN); 973 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 974 break; 975 case BIO_WRITE: 976 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 977 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 978 break; 979 case BIO_DELETE: 980 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD); 981 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 982 break; 983 default: 984 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 985 } 986 987 if (bp->bio_flags & BIO_ORDERED) 988 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER); 989 990 return (req); 991 } 992 993 static int 994 vtblk_request_execute(struct vtblk_request *req, int flags) 995 { 996 struct vtblk_softc *sc = req->vbr_sc; 997 struct bio *bp = req->vbr_bp; 998 int error = 0; 999 1000 /* 1001 * Call via bus_dmamap_load_bio or directly depending on whether we 1002 * have a buffer we need to map. If we don't have a busdma map, 1003 * try to perform the I/O directly and hope that it works (this will 1004 * happen when dumping). 1005 */ 1006 if ((req->vbr_mapp != NULL) && 1007 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) { 1008 error = bus_dmamap_load_bio(sc->vtblk_dmat, req->vbr_mapp, 1009 req->vbr_bp, vtblk_request_execute_cb, req, flags); 1010 if (error == EINPROGRESS) { 1011 req->vbr_busdma_wait = 1; 1012 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_WAIT; 1013 } 1014 } else { 1015 vtblk_request_execute_cb(req, NULL, 0, 0); 1016 } 1017 1018 return (error ? error : req->vbr_error); 1019 } 1020 1021 static void 1022 vtblk_request_execute_cb(void * callback_arg, bus_dma_segment_t * segs, 1023 int nseg, int error) 1024 { 1025 struct vtblk_request *req; 1026 struct vtblk_softc *sc; 1027 struct virtqueue *vq; 1028 struct sglist *sg; 1029 struct bio *bp; 1030 int ordered, readable, writable, i; 1031 1032 req = (struct vtblk_request *)callback_arg; 1033 sc = req->vbr_sc; 1034 vq = sc->vtblk_vq; 1035 sg = sc->vtblk_sglist; 1036 bp = req->vbr_bp; 1037 ordered = 0; 1038 writable = 0; 1039 1040 /* 1041 * If we paused request queueing while we waited for busdma to call us 1042 * asynchronously, unpause it now; this request made it through so we 1043 * don't need to worry about others getting ahead of us. (Note that we 1044 * hold the device mutex so nothing will happen until after we return 1045 * anyway.) 1046 */ 1047 if (req->vbr_busdma_wait) 1048 sc->vtblk_flags &= ~VTBLK_FLAG_BUSDMA_WAIT; 1049 1050 /* Fail on errors from busdma. */ 1051 if (error) 1052 goto out1; 1053 1054 /* 1055 * Some hosts (such as bhyve) do not implement the barrier feature, 1056 * so we emulate it in the driver by allowing the barrier request 1057 * to be the only one in flight. 1058 */ 1059 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 1060 if (sc->vtblk_req_ordered != NULL) { 1061 error = EBUSY; 1062 goto out; 1063 } 1064 if (bp->bio_flags & BIO_ORDERED) { 1065 if (!virtqueue_empty(vq)) { 1066 error = EBUSY; 1067 goto out; 1068 } 1069 ordered = 1; 1070 req->vbr_hdr.type &= vtblk_gtoh32(sc, 1071 ~VIRTIO_BLK_T_BARRIER); 1072 } 1073 } 1074 1075 sglist_reset(sg); 1076 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 1077 1078 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 1079 /* 1080 * We cast bus_addr_t to vm_paddr_t here; since we skip the 1081 * iommu mapping (see vtblk_attach) this should be safe. 1082 */ 1083 for (i = 0; i < nseg; i++) { 1084 error = sglist_append_phys(sg, 1085 (vm_paddr_t)segs[i].ds_addr, segs[i].ds_len); 1086 if (error || sg->sg_nseg == sg->sg_maxseg) { 1087 panic("%s: bio %p data buffer too big %d", 1088 __func__, bp, error); 1089 } 1090 } 1091 1092 /* Special handling for dump, which bypasses busdma. */ 1093 if (req->vbr_mapp == NULL) { 1094 error = sglist_append_bio(sg, bp); 1095 if (error || sg->sg_nseg == sg->sg_maxseg) { 1096 panic("%s: bio %p data buffer too big %d", 1097 __func__, bp, error); 1098 } 1099 } 1100 1101 /* BIO_READ means the host writes into our buffer. */ 1102 if (bp->bio_cmd == BIO_READ) 1103 writable = sg->sg_nseg - 1; 1104 } else if (bp->bio_cmd == BIO_DELETE) { 1105 struct virtio_blk_discard_write_zeroes *discard; 1106 1107 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO); 1108 if (discard == NULL) { 1109 error = ENOMEM; 1110 goto out; 1111 } 1112 1113 bp->bio_driver1 = discard; 1114 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 1115 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE); 1116 error = sglist_append(sg, discard, sizeof(*discard)); 1117 if (error || sg->sg_nseg == sg->sg_maxseg) { 1118 panic("%s: bio %p data buffer too big %d", 1119 __func__, bp, error); 1120 } 1121 } 1122 1123 writable++; 1124 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 1125 readable = sg->sg_nseg - writable; 1126 1127 if (req->vbr_mapp != NULL) { 1128 switch (bp->bio_cmd) { 1129 case BIO_READ: 1130 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1131 BUS_DMASYNC_PREREAD); 1132 break; 1133 case BIO_WRITE: 1134 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1135 BUS_DMASYNC_PREWRITE); 1136 break; 1137 } 1138 } 1139 1140 error = virtqueue_enqueue(vq, req, sg, readable, writable); 1141 if (error == 0 && ordered) 1142 sc->vtblk_req_ordered = req; 1143 1144 /* 1145 * If we were called asynchronously, we need to notify the queue that 1146 * we've added a new request, since the notification from startio was 1147 * performed already. 1148 */ 1149 if (error == 0 && req->vbr_busdma_wait) 1150 virtqueue_notify(vq); 1151 1152 out: 1153 if (error && (req->vbr_mapp != NULL)) 1154 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp); 1155 out1: 1156 if (error && req->vbr_requeue_on_error) 1157 vtblk_request_requeue_ready(sc, req); 1158 req->vbr_error = error; 1159 } 1160 1161 static int 1162 vtblk_request_error(struct vtblk_request *req) 1163 { 1164 int error; 1165 1166 switch (req->vbr_ack) { 1167 case VIRTIO_BLK_S_OK: 1168 error = 0; 1169 break; 1170 case VIRTIO_BLK_S_UNSUPP: 1171 error = ENOTSUP; 1172 break; 1173 default: 1174 error = EIO; 1175 break; 1176 } 1177 1178 return (error); 1179 } 1180 1181 static void 1182 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1183 { 1184 struct vtblk_request *req; 1185 struct bio *bp; 1186 1187 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1188 if (sc->vtblk_req_ordered != NULL) { 1189 MPASS(sc->vtblk_req_ordered == req); 1190 sc->vtblk_req_ordered = NULL; 1191 } 1192 1193 bp = req->vbr_bp; 1194 if (req->vbr_mapp != NULL) { 1195 switch (bp->bio_cmd) { 1196 case BIO_READ: 1197 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1198 BUS_DMASYNC_POSTREAD); 1199 bus_dmamap_unload(sc->vtblk_dmat, 1200 req->vbr_mapp); 1201 break; 1202 case BIO_WRITE: 1203 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp, 1204 BUS_DMASYNC_POSTWRITE); 1205 bus_dmamap_unload(sc->vtblk_dmat, 1206 req->vbr_mapp); 1207 break; 1208 } 1209 } 1210 bp->bio_error = vtblk_request_error(req); 1211 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 1212 1213 vtblk_request_enqueue(sc, req); 1214 } 1215 } 1216 1217 static void 1218 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1219 { 1220 struct bio *bp, *tmp; 1221 1222 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 1223 if (bp->bio_error != 0) 1224 disk_err(bp, "hard error", -1, 1); 1225 vtblk_bio_done(sc, bp, bp->bio_error); 1226 } 1227 } 1228 1229 static void 1230 vtblk_drain_vq(struct vtblk_softc *sc) 1231 { 1232 struct virtqueue *vq; 1233 struct vtblk_request *req; 1234 int last; 1235 1236 vq = sc->vtblk_vq; 1237 last = 0; 1238 1239 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1240 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1241 vtblk_request_enqueue(sc, req); 1242 } 1243 1244 sc->vtblk_req_ordered = NULL; 1245 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1246 } 1247 1248 static void 1249 vtblk_drain(struct vtblk_softc *sc) 1250 { 1251 struct bio_queue_head *bioq; 1252 struct vtblk_request *req; 1253 struct bio *bp; 1254 1255 bioq = &sc->vtblk_bioq; 1256 1257 if (sc->vtblk_vq != NULL) { 1258 struct bio_queue queue; 1259 1260 TAILQ_INIT(&queue); 1261 vtblk_queue_completed(sc, &queue); 1262 vtblk_done_completed(sc, &queue); 1263 1264 vtblk_drain_vq(sc); 1265 } 1266 1267 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1268 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1269 vtblk_request_enqueue(sc, req); 1270 } 1271 1272 while (bioq_first(bioq) != NULL) { 1273 bp = bioq_takefirst(bioq); 1274 vtblk_bio_done(sc, bp, ENXIO); 1275 } 1276 1277 vtblk_request_free(sc); 1278 } 1279 1280 static void 1281 vtblk_startio(struct vtblk_softc *sc) 1282 { 1283 struct virtqueue *vq; 1284 struct vtblk_request *req; 1285 int enq; 1286 1287 VTBLK_LOCK_ASSERT(sc); 1288 vq = sc->vtblk_vq; 1289 enq = 0; 1290 1291 if (sc->vtblk_flags & (VTBLK_FLAG_SUSPEND | VTBLK_FLAG_BUSDMA_WAIT)) 1292 return; 1293 1294 while (!virtqueue_full(vq)) { 1295 req = vtblk_request_next(sc); 1296 if (req == NULL) 1297 break; 1298 1299 req->vbr_requeue_on_error = 1; 1300 if (vtblk_request_execute(req, BUS_DMA_WAITOK)) 1301 break; 1302 1303 enq++; 1304 } 1305 1306 if (enq > 0) 1307 virtqueue_notify(vq); 1308 } 1309 1310 static void 1311 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1312 { 1313 1314 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1315 if (sc != NULL) 1316 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1317 1318 if (error) { 1319 bp->bio_resid = bp->bio_bcount; 1320 bp->bio_error = error; 1321 bp->bio_flags |= BIO_ERROR; 1322 } else { 1323 kmsan_mark_bio(bp, KMSAN_STATE_INITED); 1324 } 1325 1326 if (bp->bio_driver1 != NULL) { 1327 free(bp->bio_driver1, M_DEVBUF); 1328 bp->bio_driver1 = NULL; 1329 } 1330 1331 biodone(bp); 1332 } 1333 1334 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1335 if (virtio_with_feature(_dev, _feature)) { \ 1336 virtio_read_device_config(_dev, \ 1337 offsetof(struct virtio_blk_config, _field), \ 1338 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1339 } 1340 1341 static void 1342 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1343 { 1344 device_t dev; 1345 1346 dev = sc->vtblk_dev; 1347 1348 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1349 1350 /* The capacity is always available. */ 1351 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1352 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1353 1354 /* Read the configuration if the feature was negotiated. */ 1355 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1356 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1357 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1358 geometry.cylinders, blkcfg); 1359 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1360 geometry.heads, blkcfg); 1361 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1362 geometry.sectors, blkcfg); 1363 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1364 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1365 topology.physical_block_exp, blkcfg); 1366 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1367 topology.alignment_offset, blkcfg); 1368 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1369 topology.min_io_size, blkcfg); 1370 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1371 topology.opt_io_size, blkcfg); 1372 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg); 1373 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors, 1374 blkcfg); 1375 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg); 1376 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment, 1377 blkcfg); 1378 } 1379 1380 #undef VTBLK_GET_CONFIG 1381 1382 static void 1383 vtblk_ident(struct vtblk_softc *sc) 1384 { 1385 struct bio buf; 1386 struct disk *dp; 1387 struct vtblk_request *req; 1388 int len, error; 1389 1390 dp = sc->vtblk_disk; 1391 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1392 1393 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1394 return; 1395 1396 req = vtblk_request_dequeue(sc); 1397 if (req == NULL) 1398 return; 1399 1400 req->vbr_ack = -1; 1401 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID); 1402 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1403 req->vbr_hdr.sector = 0; 1404 1405 req->vbr_bp = &buf; 1406 g_reset_bio(&buf); 1407 1408 buf.bio_cmd = BIO_READ; 1409 buf.bio_data = dp->d_ident; 1410 buf.bio_bcount = len; 1411 1412 VTBLK_LOCK(sc); 1413 error = vtblk_poll_request(sc, req); 1414 VTBLK_UNLOCK(sc); 1415 1416 vtblk_request_enqueue(sc, req); 1417 1418 if (error) { 1419 device_printf(sc->vtblk_dev, 1420 "error getting device identifier: %d\n", error); 1421 } 1422 } 1423 1424 static int 1425 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1426 { 1427 struct virtqueue *vq; 1428 int error; 1429 1430 vq = sc->vtblk_vq; 1431 1432 if (!virtqueue_empty(vq)) 1433 return (EBUSY); 1434 1435 error = vtblk_request_execute(req, BUS_DMA_NOWAIT); 1436 if (error) 1437 return (error); 1438 1439 virtqueue_notify(vq); 1440 virtqueue_poll(vq, NULL); 1441 1442 error = vtblk_request_error(req); 1443 if (error && bootverbose) { 1444 device_printf(sc->vtblk_dev, 1445 "%s: IO error: %d\n", __func__, error); 1446 } 1447 1448 return (error); 1449 } 1450 1451 static int 1452 vtblk_quiesce(struct vtblk_softc *sc) 1453 { 1454 int error; 1455 1456 VTBLK_LOCK_ASSERT(sc); 1457 error = 0; 1458 1459 while (!virtqueue_empty(sc->vtblk_vq)) { 1460 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1461 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1462 error = EBUSY; 1463 break; 1464 } 1465 } 1466 1467 return (error); 1468 } 1469 1470 static void 1471 vtblk_vq_intr(void *xsc) 1472 { 1473 struct vtblk_softc *sc; 1474 struct virtqueue *vq; 1475 struct bio_queue queue; 1476 1477 sc = xsc; 1478 vq = sc->vtblk_vq; 1479 TAILQ_INIT(&queue); 1480 1481 VTBLK_LOCK(sc); 1482 1483 again: 1484 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1485 goto out; 1486 1487 vtblk_queue_completed(sc, &queue); 1488 vtblk_startio(sc); 1489 1490 if (virtqueue_enable_intr(vq) != 0) { 1491 virtqueue_disable_intr(vq); 1492 goto again; 1493 } 1494 1495 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1496 wakeup(&sc->vtblk_vq); 1497 1498 out: 1499 VTBLK_UNLOCK(sc); 1500 vtblk_done_completed(sc, &queue); 1501 } 1502 1503 static void 1504 vtblk_stop(struct vtblk_softc *sc) 1505 { 1506 1507 virtqueue_disable_intr(sc->vtblk_vq); 1508 virtio_stop(sc->vtblk_dev); 1509 } 1510 1511 static void 1512 vtblk_dump_quiesce(struct vtblk_softc *sc) 1513 { 1514 1515 /* 1516 * Spin here until all the requests in-flight at the time of the 1517 * dump are completed and queued. The queued requests will be 1518 * biodone'd once the dump is finished. 1519 */ 1520 while (!virtqueue_empty(sc->vtblk_vq)) 1521 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1522 } 1523 1524 static int 1525 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1526 size_t length) 1527 { 1528 struct bio buf; 1529 struct vtblk_request *req; 1530 1531 req = &sc->vtblk_dump_request; 1532 req->vbr_sc = sc; 1533 req->vbr_ack = -1; 1534 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 1535 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1536 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE); 1537 1538 req->vbr_bp = &buf; 1539 g_reset_bio(&buf); 1540 1541 buf.bio_cmd = BIO_WRITE; 1542 buf.bio_data = virtual; 1543 buf.bio_bcount = length; 1544 1545 return (vtblk_poll_request(sc, req)); 1546 } 1547 1548 static int 1549 vtblk_dump_flush(struct vtblk_softc *sc) 1550 { 1551 struct bio buf; 1552 struct vtblk_request *req; 1553 1554 req = &sc->vtblk_dump_request; 1555 req->vbr_sc = sc; 1556 req->vbr_ack = -1; 1557 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 1558 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1559 req->vbr_hdr.sector = 0; 1560 1561 req->vbr_bp = &buf; 1562 g_reset_bio(&buf); 1563 1564 buf.bio_cmd = BIO_FLUSH; 1565 1566 return (vtblk_poll_request(sc, req)); 1567 } 1568 1569 static void 1570 vtblk_dump_complete(struct vtblk_softc *sc) 1571 { 1572 1573 vtblk_dump_flush(sc); 1574 1575 VTBLK_UNLOCK(sc); 1576 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1577 VTBLK_LOCK(sc); 1578 } 1579 1580 static void 1581 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1582 { 1583 1584 /* Set either writeback (1) or writethrough (0) mode. */ 1585 virtio_write_dev_config_1(sc->vtblk_dev, 1586 offsetof(struct virtio_blk_config, wce), wc); 1587 } 1588 1589 static int 1590 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1591 struct virtio_blk_config *blkcfg) 1592 { 1593 int wc; 1594 1595 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) { 1596 wc = vtblk_tunable_int(sc, "writecache_mode", 1597 vtblk_writecache_mode); 1598 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1599 vtblk_set_write_cache(sc, wc); 1600 else 1601 wc = blkcfg->wce; 1602 } else 1603 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH); 1604 1605 return (wc); 1606 } 1607 1608 static int 1609 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1610 { 1611 struct vtblk_softc *sc; 1612 int wc, error; 1613 1614 sc = oidp->oid_arg1; 1615 wc = sc->vtblk_write_cache; 1616 1617 error = sysctl_handle_int(oidp, &wc, 0, req); 1618 if (error || req->newptr == NULL) 1619 return (error); 1620 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0) 1621 return (EPERM); 1622 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1623 return (EINVAL); 1624 1625 VTBLK_LOCK(sc); 1626 sc->vtblk_write_cache = wc; 1627 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1628 VTBLK_UNLOCK(sc); 1629 1630 return (0); 1631 } 1632 1633 static void 1634 vtblk_setup_sysctl(struct vtblk_softc *sc) 1635 { 1636 device_t dev; 1637 struct sysctl_ctx_list *ctx; 1638 struct sysctl_oid *tree; 1639 struct sysctl_oid_list *child; 1640 1641 dev = sc->vtblk_dev; 1642 ctx = device_get_sysctl_ctx(dev); 1643 tree = device_get_sysctl_tree(dev); 1644 child = SYSCTL_CHILDREN(tree); 1645 1646 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1647 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0, 1648 vtblk_write_cache_sysctl, "I", 1649 "Write cache mode (writethrough (0) or writeback (1))"); 1650 } 1651 1652 static int 1653 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1654 { 1655 char path[64]; 1656 1657 snprintf(path, sizeof(path), 1658 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1659 TUNABLE_INT_FETCH(path, &def); 1660 1661 return (def); 1662 } 1663