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 *, vm_offset_t, 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 static devclass_t vtblk_devclass; 272 273 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_devclass, 274 vtblk_modevent, 0); 275 MODULE_VERSION(virtio_blk, 1); 276 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 277 278 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter"); 279 280 static int 281 vtblk_modevent(module_t mod, int type, void *unused) 282 { 283 int error; 284 285 error = 0; 286 287 switch (type) { 288 case MOD_LOAD: 289 case MOD_QUIESCE: 290 case MOD_UNLOAD: 291 case MOD_SHUTDOWN: 292 break; 293 default: 294 error = EOPNOTSUPP; 295 break; 296 } 297 298 return (error); 299 } 300 301 static int 302 vtblk_probe(device_t dev) 303 { 304 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk)); 305 } 306 307 static int 308 vtblk_attach(device_t dev) 309 { 310 struct vtblk_softc *sc; 311 struct virtio_blk_config blkcfg; 312 int error; 313 314 sc = device_get_softc(dev); 315 sc->vtblk_dev = dev; 316 virtio_set_feature_desc(dev, vtblk_feature_desc); 317 318 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 319 bioq_init(&sc->vtblk_bioq); 320 TAILQ_INIT(&sc->vtblk_dump_queue); 321 TAILQ_INIT(&sc->vtblk_req_free); 322 TAILQ_INIT(&sc->vtblk_req_ready); 323 324 vtblk_setup_sysctl(sc); 325 326 error = vtblk_setup_features(sc); 327 if (error) { 328 device_printf(dev, "cannot setup features\n"); 329 goto fail; 330 } 331 332 vtblk_read_config(sc, &blkcfg); 333 334 /* 335 * With the current sglist(9) implementation, it is not easy 336 * for us to support a maximum segment size as adjacent 337 * segments are coalesced. For now, just make sure it's larger 338 * than the maximum supported transfer size. 339 */ 340 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 341 if (blkcfg.size_max < maxphys) { 342 error = ENOTSUP; 343 device_printf(dev, "host requires unsupported " 344 "maximum segment size feature\n"); 345 goto fail; 346 } 347 } 348 349 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 350 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 351 error = EINVAL; 352 device_printf(dev, "fewer than minimum number of segments " 353 "allowed: %d\n", sc->vtblk_max_nsegs); 354 goto fail; 355 } 356 357 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 358 if (sc->vtblk_sglist == NULL) { 359 error = ENOMEM; 360 device_printf(dev, "cannot allocate sglist\n"); 361 goto fail; 362 } 363 364 error = vtblk_alloc_virtqueue(sc); 365 if (error) { 366 device_printf(dev, "cannot allocate virtqueue\n"); 367 goto fail; 368 } 369 370 error = vtblk_request_prealloc(sc); 371 if (error) { 372 device_printf(dev, "cannot preallocate requests\n"); 373 goto fail; 374 } 375 376 vtblk_alloc_disk(sc, &blkcfg); 377 378 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 379 if (error) { 380 device_printf(dev, "cannot setup virtqueue interrupt\n"); 381 goto fail; 382 } 383 384 virtqueue_enable_intr(sc->vtblk_vq); 385 386 fail: 387 if (error) 388 vtblk_detach(dev); 389 390 return (error); 391 } 392 393 static int 394 vtblk_detach(device_t dev) 395 { 396 struct vtblk_softc *sc; 397 398 sc = device_get_softc(dev); 399 400 VTBLK_LOCK(sc); 401 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 402 if (device_is_attached(dev)) 403 vtblk_stop(sc); 404 VTBLK_UNLOCK(sc); 405 406 vtblk_drain(sc); 407 408 if (sc->vtblk_disk != NULL) { 409 disk_destroy(sc->vtblk_disk); 410 sc->vtblk_disk = NULL; 411 } 412 413 if (sc->vtblk_sglist != NULL) { 414 sglist_free(sc->vtblk_sglist); 415 sc->vtblk_sglist = NULL; 416 } 417 418 VTBLK_LOCK_DESTROY(sc); 419 420 return (0); 421 } 422 423 static int 424 vtblk_suspend(device_t dev) 425 { 426 struct vtblk_softc *sc; 427 int error; 428 429 sc = device_get_softc(dev); 430 431 VTBLK_LOCK(sc); 432 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 433 /* XXX BMV: virtio_stop(), etc needed here? */ 434 error = vtblk_quiesce(sc); 435 if (error) 436 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 437 VTBLK_UNLOCK(sc); 438 439 return (error); 440 } 441 442 static int 443 vtblk_resume(device_t dev) 444 { 445 struct vtblk_softc *sc; 446 447 sc = device_get_softc(dev); 448 449 VTBLK_LOCK(sc); 450 /* XXX BMV: virtio_reinit(), etc needed here? */ 451 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 452 vtblk_startio(sc); 453 VTBLK_UNLOCK(sc); 454 455 return (0); 456 } 457 458 static int 459 vtblk_shutdown(device_t dev) 460 { 461 462 return (0); 463 } 464 465 static int 466 vtblk_attach_completed(device_t dev) 467 { 468 struct vtblk_softc *sc; 469 470 sc = device_get_softc(dev); 471 472 /* 473 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be 474 * processed after the device acknowledged 475 * VIRTIO_CONFIG_STATUS_DRIVER_OK. 476 */ 477 vtblk_create_disk(sc); 478 return (0); 479 } 480 481 static int 482 vtblk_config_change(device_t dev) 483 { 484 struct vtblk_softc *sc; 485 struct virtio_blk_config blkcfg; 486 uint64_t capacity; 487 488 sc = device_get_softc(dev); 489 490 vtblk_read_config(sc, &blkcfg); 491 492 /* Capacity is always in 512-byte units. */ 493 capacity = blkcfg.capacity * VTBLK_BSIZE; 494 495 if (sc->vtblk_disk->d_mediasize != capacity) 496 vtblk_resize_disk(sc, capacity); 497 498 return (0); 499 } 500 501 static int 502 vtblk_open(struct disk *dp) 503 { 504 struct vtblk_softc *sc; 505 506 if ((sc = dp->d_drv1) == NULL) 507 return (ENXIO); 508 509 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 510 } 511 512 static int 513 vtblk_close(struct disk *dp) 514 { 515 struct vtblk_softc *sc; 516 517 if ((sc = dp->d_drv1) == NULL) 518 return (ENXIO); 519 520 return (0); 521 } 522 523 static int 524 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 525 struct thread *td) 526 { 527 struct vtblk_softc *sc; 528 529 if ((sc = dp->d_drv1) == NULL) 530 return (ENXIO); 531 532 return (ENOTTY); 533 } 534 535 static int 536 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 537 size_t length) 538 { 539 struct disk *dp; 540 struct vtblk_softc *sc; 541 int error; 542 543 dp = arg; 544 error = 0; 545 546 if ((sc = dp->d_drv1) == NULL) 547 return (ENXIO); 548 549 VTBLK_LOCK(sc); 550 551 vtblk_dump_quiesce(sc); 552 553 if (length > 0) 554 error = vtblk_dump_write(sc, virtual, offset, length); 555 if (error || (virtual == NULL && offset == 0)) 556 vtblk_dump_complete(sc); 557 558 VTBLK_UNLOCK(sc); 559 560 return (error); 561 } 562 563 static void 564 vtblk_strategy(struct bio *bp) 565 { 566 struct vtblk_softc *sc; 567 568 if ((sc = bp->bio_disk->d_drv1) == NULL) { 569 vtblk_bio_done(NULL, bp, EINVAL); 570 return; 571 } 572 573 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) && 574 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) { 575 vtblk_bio_done(sc, bp, EOPNOTSUPP); 576 return; 577 } 578 579 VTBLK_LOCK(sc); 580 581 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 582 VTBLK_UNLOCK(sc); 583 vtblk_bio_done(sc, bp, ENXIO); 584 return; 585 } 586 587 bioq_insert_tail(&sc->vtblk_bioq, bp); 588 vtblk_startio(sc); 589 590 VTBLK_UNLOCK(sc); 591 } 592 593 static int 594 vtblk_negotiate_features(struct vtblk_softc *sc) 595 { 596 device_t dev; 597 uint64_t features; 598 599 dev = sc->vtblk_dev; 600 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES : 601 VTBLK_LEGACY_FEATURES; 602 603 sc->vtblk_features = virtio_negotiate_features(dev, features); 604 return (virtio_finalize_features(dev)); 605 } 606 607 static int 608 vtblk_setup_features(struct vtblk_softc *sc) 609 { 610 device_t dev; 611 int error; 612 613 dev = sc->vtblk_dev; 614 615 error = vtblk_negotiate_features(sc); 616 if (error) 617 return (error); 618 619 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 620 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 621 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 622 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG; 623 624 /* Legacy. */ 625 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 626 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 627 628 return (0); 629 } 630 631 static int 632 vtblk_maximum_segments(struct vtblk_softc *sc, 633 struct virtio_blk_config *blkcfg) 634 { 635 device_t dev; 636 int nsegs; 637 638 dev = sc->vtblk_dev; 639 nsegs = VTBLK_MIN_SEGMENTS; 640 641 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 642 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1); 643 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 644 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 645 } else 646 nsegs += 1; 647 648 return (nsegs); 649 } 650 651 static int 652 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 653 { 654 device_t dev; 655 struct vq_alloc_info vq_info; 656 657 dev = sc->vtblk_dev; 658 659 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 660 vtblk_vq_intr, sc, &sc->vtblk_vq, 661 "%s request", device_get_nameunit(dev)); 662 663 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 664 } 665 666 static void 667 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 668 { 669 device_t dev; 670 struct disk *dp; 671 int error; 672 673 dev = sc->vtblk_dev; 674 dp = sc->vtblk_disk; 675 676 dp->d_mediasize = new_capacity; 677 if (bootverbose) { 678 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 679 (uintmax_t) dp->d_mediasize >> 20, 680 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 681 dp->d_sectorsize); 682 } 683 684 error = disk_resize(dp, M_NOWAIT); 685 if (error) { 686 device_printf(dev, 687 "disk_resize(9) failed, error: %d\n", error); 688 } 689 } 690 691 static void 692 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 693 { 694 device_t dev; 695 struct disk *dp; 696 697 dev = sc->vtblk_dev; 698 699 sc->vtblk_disk = dp = disk_alloc(); 700 dp->d_open = vtblk_open; 701 dp->d_close = vtblk_close; 702 dp->d_ioctl = vtblk_ioctl; 703 dp->d_strategy = vtblk_strategy; 704 dp->d_name = VTBLK_DISK_NAME; 705 dp->d_unit = device_get_unit(dev); 706 dp->d_drv1 = sc; 707 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION; 708 dp->d_hba_vendor = virtio_get_vendor(dev); 709 dp->d_hba_device = virtio_get_device(dev); 710 dp->d_hba_subvendor = virtio_get_subvendor(dev); 711 dp->d_hba_subdevice = virtio_get_subdevice(dev); 712 713 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 714 dp->d_flags |= DISKFLAG_WRITE_PROTECT; 715 else { 716 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 717 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 718 dp->d_dump = vtblk_dump; 719 } 720 721 /* Capacity is always in 512-byte units. */ 722 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE; 723 724 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 725 dp->d_sectorsize = blkcfg->blk_size; 726 else 727 dp->d_sectorsize = VTBLK_BSIZE; 728 729 /* 730 * The VirtIO maximum I/O size is given in terms of segments. 731 * However, FreeBSD limits I/O size by logical buffer size, not 732 * by physically contiguous pages. Therefore, we have to assume 733 * no pages are contiguous. This may impose an artificially low 734 * maximum I/O size. But in practice, since QEMU advertises 128 735 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 736 * which is typically greater than maxphys. Eventually we should 737 * just advertise maxphys and split buffers that are too big. 738 * 739 * Note we must subtract one additional segment in case of non 740 * page aligned buffers. 741 */ 742 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 743 PAGE_SIZE; 744 if (dp->d_maxsize < PAGE_SIZE) 745 dp->d_maxsize = PAGE_SIZE; /* XXX */ 746 747 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 748 dp->d_fwsectors = blkcfg->geometry.sectors; 749 dp->d_fwheads = blkcfg->geometry.heads; 750 } 751 752 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 753 blkcfg->topology.physical_block_exp > 0) { 754 dp->d_stripesize = dp->d_sectorsize * 755 (1 << blkcfg->topology.physical_block_exp); 756 dp->d_stripeoffset = (dp->d_stripesize - 757 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 758 dp->d_stripesize; 759 } 760 761 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) { 762 dp->d_flags |= DISKFLAG_CANDELETE; 763 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE; 764 } 765 766 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 767 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 768 else 769 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 770 } 771 772 static void 773 vtblk_create_disk(struct vtblk_softc *sc) 774 { 775 struct disk *dp; 776 777 dp = sc->vtblk_disk; 778 779 vtblk_ident(sc); 780 781 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 782 (uintmax_t) dp->d_mediasize >> 20, 783 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 784 dp->d_sectorsize); 785 786 disk_create(dp, DISK_VERSION); 787 } 788 789 static int 790 vtblk_request_prealloc(struct vtblk_softc *sc) 791 { 792 struct vtblk_request *req; 793 int i, nreqs; 794 795 nreqs = virtqueue_size(sc->vtblk_vq); 796 797 /* 798 * Preallocate sufficient requests to keep the virtqueue full. Each 799 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 800 * the number allocated when indirect descriptors are not available. 801 */ 802 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 803 nreqs /= VTBLK_MIN_SEGMENTS; 804 805 for (i = 0; i < nreqs; i++) { 806 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 807 if (req == NULL) 808 return (ENOMEM); 809 810 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 811 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 812 813 sc->vtblk_request_count++; 814 vtblk_request_enqueue(sc, req); 815 } 816 817 return (0); 818 } 819 820 static void 821 vtblk_request_free(struct vtblk_softc *sc) 822 { 823 struct vtblk_request *req; 824 825 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 826 827 while ((req = vtblk_request_dequeue(sc)) != NULL) { 828 sc->vtblk_request_count--; 829 free(req, M_DEVBUF); 830 } 831 832 KASSERT(sc->vtblk_request_count == 0, 833 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 834 } 835 836 static struct vtblk_request * 837 vtblk_request_dequeue(struct vtblk_softc *sc) 838 { 839 struct vtblk_request *req; 840 841 req = TAILQ_FIRST(&sc->vtblk_req_free); 842 if (req != NULL) { 843 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 844 bzero(req, sizeof(struct vtblk_request)); 845 } 846 847 return (req); 848 } 849 850 static void 851 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 852 { 853 854 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 855 } 856 857 static struct vtblk_request * 858 vtblk_request_next_ready(struct vtblk_softc *sc) 859 { 860 struct vtblk_request *req; 861 862 req = TAILQ_FIRST(&sc->vtblk_req_ready); 863 if (req != NULL) 864 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 865 866 return (req); 867 } 868 869 static void 870 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 871 { 872 873 /* NOTE: Currently, there will be at most one request in the queue. */ 874 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 875 } 876 877 static struct vtblk_request * 878 vtblk_request_next(struct vtblk_softc *sc) 879 { 880 struct vtblk_request *req; 881 882 req = vtblk_request_next_ready(sc); 883 if (req != NULL) 884 return (req); 885 886 return (vtblk_request_bio(sc)); 887 } 888 889 static struct vtblk_request * 890 vtblk_request_bio(struct vtblk_softc *sc) 891 { 892 struct bio_queue_head *bioq; 893 struct vtblk_request *req; 894 struct bio *bp; 895 896 bioq = &sc->vtblk_bioq; 897 898 if (bioq_first(bioq) == NULL) 899 return (NULL); 900 901 req = vtblk_request_dequeue(sc); 902 if (req == NULL) 903 return (NULL); 904 905 bp = bioq_takefirst(bioq); 906 req->vbr_bp = bp; 907 req->vbr_ack = -1; 908 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 909 910 switch (bp->bio_cmd) { 911 case BIO_FLUSH: 912 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 913 req->vbr_hdr.sector = 0; 914 break; 915 case BIO_READ: 916 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN); 917 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 918 break; 919 case BIO_WRITE: 920 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 921 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 922 break; 923 case BIO_DELETE: 924 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD); 925 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 926 break; 927 default: 928 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 929 } 930 931 if (bp->bio_flags & BIO_ORDERED) 932 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER); 933 934 return (req); 935 } 936 937 static int 938 vtblk_request_execute(struct vtblk_softc *sc, struct vtblk_request *req) 939 { 940 struct virtqueue *vq; 941 struct sglist *sg; 942 struct bio *bp; 943 int ordered, readable, writable, error; 944 945 vq = sc->vtblk_vq; 946 sg = sc->vtblk_sglist; 947 bp = req->vbr_bp; 948 ordered = 0; 949 writable = 0; 950 951 /* 952 * Some hosts (such as bhyve) do not implement the barrier feature, 953 * so we emulate it in the driver by allowing the barrier request 954 * to be the only one in flight. 955 */ 956 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 957 if (sc->vtblk_req_ordered != NULL) 958 return (EBUSY); 959 if (bp->bio_flags & BIO_ORDERED) { 960 if (!virtqueue_empty(vq)) 961 return (EBUSY); 962 ordered = 1; 963 req->vbr_hdr.type &= vtblk_gtoh32(sc, 964 ~VIRTIO_BLK_T_BARRIER); 965 } 966 } 967 968 sglist_reset(sg); 969 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 970 971 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 972 error = sglist_append_bio(sg, bp); 973 if (error || sg->sg_nseg == sg->sg_maxseg) { 974 panic("%s: bio %p data buffer too big %d", 975 __func__, bp, error); 976 } 977 978 /* BIO_READ means the host writes into our buffer. */ 979 if (bp->bio_cmd == BIO_READ) 980 writable = sg->sg_nseg - 1; 981 } else if (bp->bio_cmd == BIO_DELETE) { 982 struct virtio_blk_discard_write_zeroes *discard; 983 984 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO); 985 if (discard == NULL) 986 return (ENOMEM); 987 988 bp->bio_driver1 = discard; 989 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 990 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE); 991 error = sglist_append(sg, discard, sizeof(*discard)); 992 if (error || sg->sg_nseg == sg->sg_maxseg) { 993 panic("%s: bio %p data buffer too big %d", 994 __func__, bp, error); 995 } 996 } 997 998 writable++; 999 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 1000 readable = sg->sg_nseg - writable; 1001 1002 error = virtqueue_enqueue(vq, req, sg, readable, writable); 1003 if (error == 0 && ordered) 1004 sc->vtblk_req_ordered = req; 1005 1006 return (error); 1007 } 1008 1009 static int 1010 vtblk_request_error(struct vtblk_request *req) 1011 { 1012 int error; 1013 1014 switch (req->vbr_ack) { 1015 case VIRTIO_BLK_S_OK: 1016 error = 0; 1017 break; 1018 case VIRTIO_BLK_S_UNSUPP: 1019 error = ENOTSUP; 1020 break; 1021 default: 1022 error = EIO; 1023 break; 1024 } 1025 1026 return (error); 1027 } 1028 1029 static void 1030 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1031 { 1032 struct vtblk_request *req; 1033 struct bio *bp; 1034 1035 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1036 if (sc->vtblk_req_ordered != NULL) { 1037 MPASS(sc->vtblk_req_ordered == req); 1038 sc->vtblk_req_ordered = NULL; 1039 } 1040 1041 bp = req->vbr_bp; 1042 bp->bio_error = vtblk_request_error(req); 1043 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 1044 1045 vtblk_request_enqueue(sc, req); 1046 } 1047 } 1048 1049 static void 1050 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1051 { 1052 struct bio *bp, *tmp; 1053 1054 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 1055 if (bp->bio_error != 0) 1056 disk_err(bp, "hard error", -1, 1); 1057 vtblk_bio_done(sc, bp, bp->bio_error); 1058 } 1059 } 1060 1061 static void 1062 vtblk_drain_vq(struct vtblk_softc *sc) 1063 { 1064 struct virtqueue *vq; 1065 struct vtblk_request *req; 1066 int last; 1067 1068 vq = sc->vtblk_vq; 1069 last = 0; 1070 1071 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1072 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1073 vtblk_request_enqueue(sc, req); 1074 } 1075 1076 sc->vtblk_req_ordered = NULL; 1077 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1078 } 1079 1080 static void 1081 vtblk_drain(struct vtblk_softc *sc) 1082 { 1083 struct bio_queue_head *bioq; 1084 struct vtblk_request *req; 1085 struct bio *bp; 1086 1087 bioq = &sc->vtblk_bioq; 1088 1089 if (sc->vtblk_vq != NULL) { 1090 struct bio_queue queue; 1091 1092 TAILQ_INIT(&queue); 1093 vtblk_queue_completed(sc, &queue); 1094 vtblk_done_completed(sc, &queue); 1095 1096 vtblk_drain_vq(sc); 1097 } 1098 1099 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1100 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1101 vtblk_request_enqueue(sc, req); 1102 } 1103 1104 while (bioq_first(bioq) != NULL) { 1105 bp = bioq_takefirst(bioq); 1106 vtblk_bio_done(sc, bp, ENXIO); 1107 } 1108 1109 vtblk_request_free(sc); 1110 } 1111 1112 static void 1113 vtblk_startio(struct vtblk_softc *sc) 1114 { 1115 struct virtqueue *vq; 1116 struct vtblk_request *req; 1117 int enq; 1118 1119 VTBLK_LOCK_ASSERT(sc); 1120 vq = sc->vtblk_vq; 1121 enq = 0; 1122 1123 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1124 return; 1125 1126 while (!virtqueue_full(vq)) { 1127 req = vtblk_request_next(sc); 1128 if (req == NULL) 1129 break; 1130 1131 if (vtblk_request_execute(sc, req) != 0) { 1132 vtblk_request_requeue_ready(sc, req); 1133 break; 1134 } 1135 1136 enq++; 1137 } 1138 1139 if (enq > 0) 1140 virtqueue_notify(vq); 1141 } 1142 1143 static void 1144 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1145 { 1146 1147 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1148 if (sc != NULL) 1149 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1150 1151 if (error) { 1152 bp->bio_resid = bp->bio_bcount; 1153 bp->bio_error = error; 1154 bp->bio_flags |= BIO_ERROR; 1155 } else { 1156 kmsan_mark_bio(bp, KMSAN_STATE_INITED); 1157 } 1158 1159 if (bp->bio_driver1 != NULL) { 1160 free(bp->bio_driver1, M_DEVBUF); 1161 bp->bio_driver1 = NULL; 1162 } 1163 1164 biodone(bp); 1165 } 1166 1167 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1168 if (virtio_with_feature(_dev, _feature)) { \ 1169 virtio_read_device_config(_dev, \ 1170 offsetof(struct virtio_blk_config, _field), \ 1171 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1172 } 1173 1174 static void 1175 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1176 { 1177 device_t dev; 1178 1179 dev = sc->vtblk_dev; 1180 1181 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1182 1183 /* The capacity is always available. */ 1184 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1185 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1186 1187 /* Read the configuration if the feature was negotiated. */ 1188 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1189 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1190 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1191 geometry.cylinders, blkcfg); 1192 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1193 geometry.heads, blkcfg); 1194 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1195 geometry.sectors, blkcfg); 1196 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1197 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1198 topology.physical_block_exp, blkcfg); 1199 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1200 topology.alignment_offset, blkcfg); 1201 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1202 topology.min_io_size, blkcfg); 1203 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1204 topology.opt_io_size, blkcfg); 1205 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg); 1206 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors, 1207 blkcfg); 1208 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg); 1209 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment, 1210 blkcfg); 1211 } 1212 1213 #undef VTBLK_GET_CONFIG 1214 1215 static void 1216 vtblk_ident(struct vtblk_softc *sc) 1217 { 1218 struct bio buf; 1219 struct disk *dp; 1220 struct vtblk_request *req; 1221 int len, error; 1222 1223 dp = sc->vtblk_disk; 1224 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1225 1226 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1227 return; 1228 1229 req = vtblk_request_dequeue(sc); 1230 if (req == NULL) 1231 return; 1232 1233 req->vbr_ack = -1; 1234 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID); 1235 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1236 req->vbr_hdr.sector = 0; 1237 1238 req->vbr_bp = &buf; 1239 g_reset_bio(&buf); 1240 1241 buf.bio_cmd = BIO_READ; 1242 buf.bio_data = dp->d_ident; 1243 buf.bio_bcount = len; 1244 1245 VTBLK_LOCK(sc); 1246 error = vtblk_poll_request(sc, req); 1247 VTBLK_UNLOCK(sc); 1248 1249 vtblk_request_enqueue(sc, req); 1250 1251 if (error) { 1252 device_printf(sc->vtblk_dev, 1253 "error getting device identifier: %d\n", error); 1254 } 1255 } 1256 1257 static int 1258 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1259 { 1260 struct virtqueue *vq; 1261 int error; 1262 1263 vq = sc->vtblk_vq; 1264 1265 if (!virtqueue_empty(vq)) 1266 return (EBUSY); 1267 1268 error = vtblk_request_execute(sc, req); 1269 if (error) 1270 return (error); 1271 1272 virtqueue_notify(vq); 1273 virtqueue_poll(vq, NULL); 1274 1275 error = vtblk_request_error(req); 1276 if (error && bootverbose) { 1277 device_printf(sc->vtblk_dev, 1278 "%s: IO error: %d\n", __func__, error); 1279 } 1280 1281 return (error); 1282 } 1283 1284 static int 1285 vtblk_quiesce(struct vtblk_softc *sc) 1286 { 1287 int error; 1288 1289 VTBLK_LOCK_ASSERT(sc); 1290 error = 0; 1291 1292 while (!virtqueue_empty(sc->vtblk_vq)) { 1293 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1294 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1295 error = EBUSY; 1296 break; 1297 } 1298 } 1299 1300 return (error); 1301 } 1302 1303 static void 1304 vtblk_vq_intr(void *xsc) 1305 { 1306 struct vtblk_softc *sc; 1307 struct virtqueue *vq; 1308 struct bio_queue queue; 1309 1310 sc = xsc; 1311 vq = sc->vtblk_vq; 1312 TAILQ_INIT(&queue); 1313 1314 VTBLK_LOCK(sc); 1315 1316 again: 1317 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1318 goto out; 1319 1320 vtblk_queue_completed(sc, &queue); 1321 vtblk_startio(sc); 1322 1323 if (virtqueue_enable_intr(vq) != 0) { 1324 virtqueue_disable_intr(vq); 1325 goto again; 1326 } 1327 1328 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1329 wakeup(&sc->vtblk_vq); 1330 1331 out: 1332 VTBLK_UNLOCK(sc); 1333 vtblk_done_completed(sc, &queue); 1334 } 1335 1336 static void 1337 vtblk_stop(struct vtblk_softc *sc) 1338 { 1339 1340 virtqueue_disable_intr(sc->vtblk_vq); 1341 virtio_stop(sc->vtblk_dev); 1342 } 1343 1344 static void 1345 vtblk_dump_quiesce(struct vtblk_softc *sc) 1346 { 1347 1348 /* 1349 * Spin here until all the requests in-flight at the time of the 1350 * dump are completed and queued. The queued requests will be 1351 * biodone'd once the dump is finished. 1352 */ 1353 while (!virtqueue_empty(sc->vtblk_vq)) 1354 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1355 } 1356 1357 static int 1358 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1359 size_t length) 1360 { 1361 struct bio buf; 1362 struct vtblk_request *req; 1363 1364 req = &sc->vtblk_dump_request; 1365 req->vbr_ack = -1; 1366 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 1367 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1368 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE); 1369 1370 req->vbr_bp = &buf; 1371 g_reset_bio(&buf); 1372 1373 buf.bio_cmd = BIO_WRITE; 1374 buf.bio_data = virtual; 1375 buf.bio_bcount = length; 1376 1377 return (vtblk_poll_request(sc, req)); 1378 } 1379 1380 static int 1381 vtblk_dump_flush(struct vtblk_softc *sc) 1382 { 1383 struct bio buf; 1384 struct vtblk_request *req; 1385 1386 req = &sc->vtblk_dump_request; 1387 req->vbr_ack = -1; 1388 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 1389 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1390 req->vbr_hdr.sector = 0; 1391 1392 req->vbr_bp = &buf; 1393 g_reset_bio(&buf); 1394 1395 buf.bio_cmd = BIO_FLUSH; 1396 1397 return (vtblk_poll_request(sc, req)); 1398 } 1399 1400 static void 1401 vtblk_dump_complete(struct vtblk_softc *sc) 1402 { 1403 1404 vtblk_dump_flush(sc); 1405 1406 VTBLK_UNLOCK(sc); 1407 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1408 VTBLK_LOCK(sc); 1409 } 1410 1411 static void 1412 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1413 { 1414 1415 /* Set either writeback (1) or writethrough (0) mode. */ 1416 virtio_write_dev_config_1(sc->vtblk_dev, 1417 offsetof(struct virtio_blk_config, wce), wc); 1418 } 1419 1420 static int 1421 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1422 struct virtio_blk_config *blkcfg) 1423 { 1424 int wc; 1425 1426 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) { 1427 wc = vtblk_tunable_int(sc, "writecache_mode", 1428 vtblk_writecache_mode); 1429 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1430 vtblk_set_write_cache(sc, wc); 1431 else 1432 wc = blkcfg->wce; 1433 } else 1434 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH); 1435 1436 return (wc); 1437 } 1438 1439 static int 1440 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1441 { 1442 struct vtblk_softc *sc; 1443 int wc, error; 1444 1445 sc = oidp->oid_arg1; 1446 wc = sc->vtblk_write_cache; 1447 1448 error = sysctl_handle_int(oidp, &wc, 0, req); 1449 if (error || req->newptr == NULL) 1450 return (error); 1451 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0) 1452 return (EPERM); 1453 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1454 return (EINVAL); 1455 1456 VTBLK_LOCK(sc); 1457 sc->vtblk_write_cache = wc; 1458 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1459 VTBLK_UNLOCK(sc); 1460 1461 return (0); 1462 } 1463 1464 static void 1465 vtblk_setup_sysctl(struct vtblk_softc *sc) 1466 { 1467 device_t dev; 1468 struct sysctl_ctx_list *ctx; 1469 struct sysctl_oid *tree; 1470 struct sysctl_oid_list *child; 1471 1472 dev = sc->vtblk_dev; 1473 ctx = device_get_sysctl_ctx(dev); 1474 tree = device_get_sysctl_tree(dev); 1475 child = SYSCTL_CHILDREN(tree); 1476 1477 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1478 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0, 1479 vtblk_write_cache_sysctl, "I", 1480 "Write cache mode (writethrough (0) or writeback (1))"); 1481 } 1482 1483 static int 1484 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1485 { 1486 char path[64]; 1487 1488 snprintf(path, sizeof(path), 1489 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1490 TUNABLE_INT_FETCH(path, &def); 1491 1492 return (def); 1493 } 1494