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