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