1 /*- 2 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 /* Driver for VirtIO block devices. */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/bio.h> 36 #include <sys/malloc.h> 37 #include <sys/module.h> 38 #include <sys/sglist.h> 39 #include <sys/sysctl.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/queue.h> 43 44 #include <geom/geom_disk.h> 45 46 #include <machine/bus.h> 47 #include <machine/resource.h> 48 #include <sys/bus.h> 49 #include <sys/rman.h> 50 51 #include <dev/virtio/virtio.h> 52 #include <dev/virtio/virtqueue.h> 53 #include <dev/virtio/block/virtio_blk.h> 54 55 #include "virtio_if.h" 56 57 struct vtblk_request { 58 struct virtio_blk_outhdr vbr_hdr; 59 struct bio *vbr_bp; 60 uint8_t vbr_ack; 61 TAILQ_ENTRY(vtblk_request) vbr_link; 62 }; 63 64 enum vtblk_cache_mode { 65 VTBLK_CACHE_WRITETHROUGH, 66 VTBLK_CACHE_WRITEBACK, 67 VTBLK_CACHE_MAX 68 }; 69 70 struct vtblk_softc { 71 device_t vtblk_dev; 72 struct mtx vtblk_mtx; 73 uint64_t vtblk_features; 74 uint32_t vtblk_flags; 75 #define VTBLK_FLAG_INDIRECT 0x0001 76 #define VTBLK_FLAG_READONLY 0x0002 77 #define VTBLK_FLAG_DETACH 0x0004 78 #define VTBLK_FLAG_SUSPEND 0x0008 79 #define VTBLK_FLAG_BARRIER 0x0010 80 #define VTBLK_FLAG_WC_CONFIG 0x0020 81 82 struct virtqueue *vtblk_vq; 83 struct sglist *vtblk_sglist; 84 struct disk *vtblk_disk; 85 86 struct bio_queue_head vtblk_bioq; 87 TAILQ_HEAD(, vtblk_request) 88 vtblk_req_free; 89 TAILQ_HEAD(, vtblk_request) 90 vtblk_req_ready; 91 struct vtblk_request *vtblk_req_ordered; 92 93 int vtblk_max_nsegs; 94 int vtblk_request_count; 95 enum vtblk_cache_mode vtblk_write_cache; 96 97 struct bio_queue vtblk_dump_queue; 98 struct vtblk_request vtblk_dump_request; 99 }; 100 101 static struct virtio_feature_desc vtblk_feature_desc[] = { 102 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 103 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 104 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 105 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 106 { VIRTIO_BLK_F_RO, "ReadOnly" }, 107 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 108 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 109 { VIRTIO_BLK_F_WCE, "WriteCache" }, 110 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 111 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, 112 113 { 0, NULL } 114 }; 115 116 static int vtblk_modevent(module_t, int, void *); 117 118 static int vtblk_probe(device_t); 119 static int vtblk_attach(device_t); 120 static int vtblk_detach(device_t); 121 static int vtblk_suspend(device_t); 122 static int vtblk_resume(device_t); 123 static int vtblk_shutdown(device_t); 124 static int vtblk_config_change(device_t); 125 126 static int vtblk_open(struct disk *); 127 static int vtblk_close(struct disk *); 128 static int vtblk_ioctl(struct disk *, u_long, void *, int, 129 struct thread *); 130 static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); 131 static void vtblk_strategy(struct bio *); 132 133 static void vtblk_negotiate_features(struct vtblk_softc *); 134 static void vtblk_setup_features(struct vtblk_softc *); 135 static int vtblk_maximum_segments(struct vtblk_softc *, 136 struct virtio_blk_config *); 137 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 138 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 139 static void vtblk_alloc_disk(struct vtblk_softc *, 140 struct virtio_blk_config *); 141 static void vtblk_create_disk(struct vtblk_softc *); 142 143 static int vtblk_request_prealloc(struct vtblk_softc *); 144 static void vtblk_request_free(struct vtblk_softc *); 145 static struct vtblk_request * 146 vtblk_request_dequeue(struct vtblk_softc *); 147 static void vtblk_request_enqueue(struct vtblk_softc *, 148 struct vtblk_request *); 149 static struct vtblk_request * 150 vtblk_request_next_ready(struct vtblk_softc *); 151 static void vtblk_request_requeue_ready(struct vtblk_softc *, 152 struct vtblk_request *); 153 static struct vtblk_request * 154 vtblk_request_next(struct vtblk_softc *); 155 static struct vtblk_request * 156 vtblk_request_bio(struct vtblk_softc *); 157 static int vtblk_request_execute(struct vtblk_softc *, 158 struct vtblk_request *); 159 static int vtblk_request_error(struct vtblk_request *); 160 161 static void vtblk_queue_completed(struct vtblk_softc *, 162 struct bio_queue *); 163 static void vtblk_done_completed(struct vtblk_softc *, 164 struct bio_queue *); 165 static void vtblk_drain_vq(struct vtblk_softc *); 166 static void vtblk_drain(struct vtblk_softc *); 167 168 static void vtblk_startio(struct vtblk_softc *); 169 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 170 171 static void vtblk_read_config(struct vtblk_softc *, 172 struct virtio_blk_config *); 173 static void vtblk_ident(struct vtblk_softc *); 174 static int vtblk_poll_request(struct vtblk_softc *, 175 struct vtblk_request *); 176 static int vtblk_quiesce(struct vtblk_softc *); 177 static void vtblk_vq_intr(void *); 178 static void vtblk_stop(struct vtblk_softc *); 179 180 static void vtblk_dump_quiesce(struct vtblk_softc *); 181 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 182 static int vtblk_dump_flush(struct vtblk_softc *); 183 static void vtblk_dump_complete(struct vtblk_softc *); 184 185 static void vtblk_set_write_cache(struct vtblk_softc *, int); 186 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 187 struct virtio_blk_config *); 188 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 189 190 static void vtblk_setup_sysctl(struct vtblk_softc *); 191 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 192 193 /* Tunables. */ 194 static int vtblk_no_ident = 0; 195 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 196 static int vtblk_writecache_mode = -1; 197 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 198 199 /* Features desired/implemented by this driver. */ 200 #define VTBLK_FEATURES \ 201 (VIRTIO_BLK_F_BARRIER | \ 202 VIRTIO_BLK_F_SIZE_MAX | \ 203 VIRTIO_BLK_F_SEG_MAX | \ 204 VIRTIO_BLK_F_GEOMETRY | \ 205 VIRTIO_BLK_F_RO | \ 206 VIRTIO_BLK_F_BLK_SIZE | \ 207 VIRTIO_BLK_F_WCE | \ 208 VIRTIO_BLK_F_TOPOLOGY | \ 209 VIRTIO_BLK_F_CONFIG_WCE | \ 210 VIRTIO_RING_F_INDIRECT_DESC) 211 212 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 213 #define VTBLK_LOCK_INIT(_sc, _name) \ 214 mtx_init(VTBLK_MTX((_sc)), (_name), \ 215 "VirtIO Block Lock", MTX_DEF) 216 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 217 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 218 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 219 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 220 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 221 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 222 223 #define VTBLK_DISK_NAME "vtbd" 224 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 225 226 /* 227 * Each block request uses at least two segments - one for the header 228 * and one for the status. 229 */ 230 #define VTBLK_MIN_SEGMENTS 2 231 232 static device_method_t vtblk_methods[] = { 233 /* Device methods. */ 234 DEVMETHOD(device_probe, vtblk_probe), 235 DEVMETHOD(device_attach, vtblk_attach), 236 DEVMETHOD(device_detach, vtblk_detach), 237 DEVMETHOD(device_suspend, vtblk_suspend), 238 DEVMETHOD(device_resume, vtblk_resume), 239 DEVMETHOD(device_shutdown, vtblk_shutdown), 240 241 /* VirtIO methods. */ 242 DEVMETHOD(virtio_config_change, vtblk_config_change), 243 244 DEVMETHOD_END 245 }; 246 247 static driver_t vtblk_driver = { 248 "vtblk", 249 vtblk_methods, 250 sizeof(struct vtblk_softc) 251 }; 252 static devclass_t vtblk_devclass; 253 254 DRIVER_MODULE(virtio_blk, virtio_mmio, vtblk_driver, vtblk_devclass, 255 vtblk_modevent, 0); 256 DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, 257 vtblk_modevent, 0); 258 MODULE_VERSION(virtio_blk, 1); 259 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 260 261 static int 262 vtblk_modevent(module_t mod, int type, void *unused) 263 { 264 int error; 265 266 error = 0; 267 268 switch (type) { 269 case MOD_LOAD: 270 case MOD_QUIESCE: 271 case MOD_UNLOAD: 272 case MOD_SHUTDOWN: 273 break; 274 default: 275 error = EOPNOTSUPP; 276 break; 277 } 278 279 return (error); 280 } 281 282 static int 283 vtblk_probe(device_t dev) 284 { 285 286 if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) 287 return (ENXIO); 288 289 device_set_desc(dev, "VirtIO Block Adapter"); 290 291 return (BUS_PROBE_DEFAULT); 292 } 293 294 static int 295 vtblk_attach(device_t dev) 296 { 297 struct vtblk_softc *sc; 298 struct virtio_blk_config blkcfg; 299 int error; 300 301 virtio_set_feature_desc(dev, vtblk_feature_desc); 302 303 sc = device_get_softc(dev); 304 sc->vtblk_dev = dev; 305 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 306 bioq_init(&sc->vtblk_bioq); 307 TAILQ_INIT(&sc->vtblk_dump_queue); 308 TAILQ_INIT(&sc->vtblk_req_free); 309 TAILQ_INIT(&sc->vtblk_req_ready); 310 311 vtblk_setup_sysctl(sc); 312 vtblk_setup_features(sc); 313 314 vtblk_read_config(sc, &blkcfg); 315 316 /* 317 * With the current sglist(9) implementation, it is not easy 318 * for us to support a maximum segment size as adjacent 319 * segments are coalesced. For now, just make sure it's larger 320 * than the maximum supported transfer size. 321 */ 322 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 323 if (blkcfg.size_max < MAXPHYS) { 324 error = ENOTSUP; 325 device_printf(dev, "host requires unsupported " 326 "maximum segment size feature\n"); 327 goto fail; 328 } 329 } 330 331 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 332 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 333 error = EINVAL; 334 device_printf(dev, "fewer than minimum number of segments " 335 "allowed: %d\n", sc->vtblk_max_nsegs); 336 goto fail; 337 } 338 339 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 340 if (sc->vtblk_sglist == NULL) { 341 error = ENOMEM; 342 device_printf(dev, "cannot allocate sglist\n"); 343 goto fail; 344 } 345 346 error = vtblk_alloc_virtqueue(sc); 347 if (error) { 348 device_printf(dev, "cannot allocate virtqueue\n"); 349 goto fail; 350 } 351 352 error = vtblk_request_prealloc(sc); 353 if (error) { 354 device_printf(dev, "cannot preallocate requests\n"); 355 goto fail; 356 } 357 358 vtblk_alloc_disk(sc, &blkcfg); 359 360 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 361 if (error) { 362 device_printf(dev, "cannot setup virtqueue interrupt\n"); 363 goto fail; 364 } 365 366 vtblk_create_disk(sc); 367 368 virtqueue_enable_intr(sc->vtblk_vq); 369 370 fail: 371 if (error) 372 vtblk_detach(dev); 373 374 return (error); 375 } 376 377 static int 378 vtblk_detach(device_t dev) 379 { 380 struct vtblk_softc *sc; 381 382 sc = device_get_softc(dev); 383 384 VTBLK_LOCK(sc); 385 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 386 if (device_is_attached(dev)) 387 vtblk_stop(sc); 388 VTBLK_UNLOCK(sc); 389 390 vtblk_drain(sc); 391 392 if (sc->vtblk_disk != NULL) { 393 disk_destroy(sc->vtblk_disk); 394 sc->vtblk_disk = NULL; 395 } 396 397 if (sc->vtblk_sglist != NULL) { 398 sglist_free(sc->vtblk_sglist); 399 sc->vtblk_sglist = NULL; 400 } 401 402 VTBLK_LOCK_DESTROY(sc); 403 404 return (0); 405 } 406 407 static int 408 vtblk_suspend(device_t dev) 409 { 410 struct vtblk_softc *sc; 411 int error; 412 413 sc = device_get_softc(dev); 414 415 VTBLK_LOCK(sc); 416 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 417 /* XXX BMV: virtio_stop(), etc needed here? */ 418 error = vtblk_quiesce(sc); 419 if (error) 420 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 421 VTBLK_UNLOCK(sc); 422 423 return (error); 424 } 425 426 static int 427 vtblk_resume(device_t dev) 428 { 429 struct vtblk_softc *sc; 430 431 sc = device_get_softc(dev); 432 433 VTBLK_LOCK(sc); 434 /* XXX BMV: virtio_reinit(), etc needed here? */ 435 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 436 vtblk_startio(sc); 437 VTBLK_UNLOCK(sc); 438 439 return (0); 440 } 441 442 static int 443 vtblk_shutdown(device_t dev) 444 { 445 446 return (0); 447 } 448 449 static int 450 vtblk_config_change(device_t dev) 451 { 452 struct vtblk_softc *sc; 453 struct virtio_blk_config blkcfg; 454 uint64_t capacity; 455 456 sc = device_get_softc(dev); 457 458 vtblk_read_config(sc, &blkcfg); 459 460 /* Capacity is always in 512-byte units. */ 461 capacity = blkcfg.capacity * 512; 462 463 if (sc->vtblk_disk->d_mediasize != capacity) 464 vtblk_resize_disk(sc, capacity); 465 466 return (0); 467 } 468 469 static int 470 vtblk_open(struct disk *dp) 471 { 472 struct vtblk_softc *sc; 473 474 if ((sc = dp->d_drv1) == NULL) 475 return (ENXIO); 476 477 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 478 } 479 480 static int 481 vtblk_close(struct disk *dp) 482 { 483 struct vtblk_softc *sc; 484 485 if ((sc = dp->d_drv1) == NULL) 486 return (ENXIO); 487 488 return (0); 489 } 490 491 static int 492 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 493 struct thread *td) 494 { 495 struct vtblk_softc *sc; 496 497 if ((sc = dp->d_drv1) == NULL) 498 return (ENXIO); 499 500 return (ENOTTY); 501 } 502 503 static int 504 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 505 size_t length) 506 { 507 struct disk *dp; 508 struct vtblk_softc *sc; 509 int error; 510 511 dp = arg; 512 error = 0; 513 514 if ((sc = dp->d_drv1) == NULL) 515 return (ENXIO); 516 517 VTBLK_LOCK(sc); 518 519 vtblk_dump_quiesce(sc); 520 521 if (length > 0) 522 error = vtblk_dump_write(sc, virtual, offset, length); 523 if (error || (virtual == NULL && offset == 0)) 524 vtblk_dump_complete(sc); 525 526 VTBLK_UNLOCK(sc); 527 528 return (error); 529 } 530 531 static void 532 vtblk_strategy(struct bio *bp) 533 { 534 struct vtblk_softc *sc; 535 536 if ((sc = bp->bio_disk->d_drv1) == NULL) { 537 vtblk_bio_done(NULL, bp, EINVAL); 538 return; 539 } 540 541 /* 542 * Fail any write if RO. Unfortunately, there does not seem to 543 * be a better way to report our readonly'ness to GEOM above. 544 */ 545 if (sc->vtblk_flags & VTBLK_FLAG_READONLY && 546 (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_FLUSH)) { 547 vtblk_bio_done(sc, bp, EROFS); 548 return; 549 } 550 551 VTBLK_LOCK(sc); 552 553 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 554 VTBLK_UNLOCK(sc); 555 vtblk_bio_done(sc, bp, ENXIO); 556 return; 557 } 558 559 bioq_insert_tail(&sc->vtblk_bioq, bp); 560 vtblk_startio(sc); 561 562 VTBLK_UNLOCK(sc); 563 } 564 565 static void 566 vtblk_negotiate_features(struct vtblk_softc *sc) 567 { 568 device_t dev; 569 uint64_t features; 570 571 dev = sc->vtblk_dev; 572 features = VTBLK_FEATURES; 573 574 sc->vtblk_features = virtio_negotiate_features(dev, features); 575 } 576 577 static void 578 vtblk_setup_features(struct vtblk_softc *sc) 579 { 580 device_t dev; 581 582 dev = sc->vtblk_dev; 583 584 vtblk_negotiate_features(sc); 585 586 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 587 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 588 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 589 sc->vtblk_flags |= VTBLK_FLAG_READONLY; 590 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 591 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 592 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 593 sc->vtblk_flags |= VTBLK_FLAG_WC_CONFIG; 594 } 595 596 static int 597 vtblk_maximum_segments(struct vtblk_softc *sc, 598 struct virtio_blk_config *blkcfg) 599 { 600 device_t dev; 601 int nsegs; 602 603 dev = sc->vtblk_dev; 604 nsegs = VTBLK_MIN_SEGMENTS; 605 606 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 607 nsegs += MIN(blkcfg->seg_max, MAXPHYS / PAGE_SIZE + 1); 608 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 609 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 610 } else 611 nsegs += 1; 612 613 return (nsegs); 614 } 615 616 static int 617 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 618 { 619 device_t dev; 620 struct vq_alloc_info vq_info; 621 622 dev = sc->vtblk_dev; 623 624 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 625 vtblk_vq_intr, sc, &sc->vtblk_vq, 626 "%s request", device_get_nameunit(dev)); 627 628 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 629 } 630 631 static void 632 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 633 { 634 device_t dev; 635 struct disk *dp; 636 int error; 637 638 dev = sc->vtblk_dev; 639 dp = sc->vtblk_disk; 640 641 dp->d_mediasize = new_capacity; 642 if (bootverbose) { 643 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 644 (uintmax_t) dp->d_mediasize >> 20, 645 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 646 dp->d_sectorsize); 647 } 648 649 error = disk_resize(dp, M_NOWAIT); 650 if (error) { 651 device_printf(dev, 652 "disk_resize(9) failed, error: %d\n", error); 653 } 654 } 655 656 static void 657 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 658 { 659 device_t dev; 660 struct disk *dp; 661 662 dev = sc->vtblk_dev; 663 664 sc->vtblk_disk = dp = disk_alloc(); 665 dp->d_open = vtblk_open; 666 dp->d_close = vtblk_close; 667 dp->d_ioctl = vtblk_ioctl; 668 dp->d_strategy = vtblk_strategy; 669 dp->d_name = VTBLK_DISK_NAME; 670 dp->d_unit = device_get_unit(dev); 671 dp->d_drv1 = sc; 672 dp->d_flags = DISKFLAG_CANFLUSHCACHE | DISKFLAG_UNMAPPED_BIO | 673 DISKFLAG_DIRECT_COMPLETION; 674 dp->d_hba_vendor = virtio_get_vendor(dev); 675 dp->d_hba_device = virtio_get_device(dev); 676 dp->d_hba_subvendor = virtio_get_subvendor(dev); 677 dp->d_hba_subdevice = virtio_get_subdevice(dev); 678 679 if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0) 680 dp->d_dump = vtblk_dump; 681 682 /* Capacity is always in 512-byte units. */ 683 dp->d_mediasize = blkcfg->capacity * 512; 684 685 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 686 dp->d_sectorsize = blkcfg->blk_size; 687 else 688 dp->d_sectorsize = 512; 689 690 /* 691 * The VirtIO maximum I/O size is given in terms of segments. 692 * However, FreeBSD limits I/O size by logical buffer size, not 693 * by physically contiguous pages. Therefore, we have to assume 694 * no pages are contiguous. This may impose an artificially low 695 * maximum I/O size. But in practice, since QEMU advertises 128 696 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 697 * which is typically greater than MAXPHYS. Eventually we should 698 * just advertise MAXPHYS and split buffers that are too big. 699 * 700 * Note we must subtract one additional segment in case of non 701 * page aligned buffers. 702 */ 703 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 704 PAGE_SIZE; 705 if (dp->d_maxsize < PAGE_SIZE) 706 dp->d_maxsize = PAGE_SIZE; /* XXX */ 707 708 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 709 dp->d_fwsectors = blkcfg->geometry.sectors; 710 dp->d_fwheads = blkcfg->geometry.heads; 711 } 712 713 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 714 blkcfg->topology.physical_block_exp > 0) { 715 dp->d_stripesize = dp->d_sectorsize * 716 (1 << blkcfg->topology.physical_block_exp); 717 dp->d_stripeoffset = (dp->d_stripesize - 718 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 719 dp->d_stripesize; 720 } 721 722 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 723 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 724 else 725 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 726 } 727 728 static void 729 vtblk_create_disk(struct vtblk_softc *sc) 730 { 731 struct disk *dp; 732 733 dp = sc->vtblk_disk; 734 735 vtblk_ident(sc); 736 737 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 738 (uintmax_t) dp->d_mediasize >> 20, 739 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 740 dp->d_sectorsize); 741 742 disk_create(dp, DISK_VERSION); 743 } 744 745 static int 746 vtblk_request_prealloc(struct vtblk_softc *sc) 747 { 748 struct vtblk_request *req; 749 int i, nreqs; 750 751 nreqs = virtqueue_size(sc->vtblk_vq); 752 753 /* 754 * Preallocate sufficient requests to keep the virtqueue full. Each 755 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 756 * the number allocated when indirect descriptors are not available. 757 */ 758 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 759 nreqs /= VTBLK_MIN_SEGMENTS; 760 761 for (i = 0; i < nreqs; i++) { 762 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 763 if (req == NULL) 764 return (ENOMEM); 765 766 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 767 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 768 769 sc->vtblk_request_count++; 770 vtblk_request_enqueue(sc, req); 771 } 772 773 return (0); 774 } 775 776 static void 777 vtblk_request_free(struct vtblk_softc *sc) 778 { 779 struct vtblk_request *req; 780 781 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 782 783 while ((req = vtblk_request_dequeue(sc)) != NULL) { 784 sc->vtblk_request_count--; 785 free(req, M_DEVBUF); 786 } 787 788 KASSERT(sc->vtblk_request_count == 0, 789 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 790 } 791 792 static struct vtblk_request * 793 vtblk_request_dequeue(struct vtblk_softc *sc) 794 { 795 struct vtblk_request *req; 796 797 req = TAILQ_FIRST(&sc->vtblk_req_free); 798 if (req != NULL) { 799 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 800 bzero(req, sizeof(struct vtblk_request)); 801 } 802 803 return (req); 804 } 805 806 static void 807 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 808 { 809 810 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 811 } 812 813 static struct vtblk_request * 814 vtblk_request_next_ready(struct vtblk_softc *sc) 815 { 816 struct vtblk_request *req; 817 818 req = TAILQ_FIRST(&sc->vtblk_req_ready); 819 if (req != NULL) 820 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 821 822 return (req); 823 } 824 825 static void 826 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 827 { 828 829 /* NOTE: Currently, there will be at most one request in the queue. */ 830 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 831 } 832 833 static struct vtblk_request * 834 vtblk_request_next(struct vtblk_softc *sc) 835 { 836 struct vtblk_request *req; 837 838 req = vtblk_request_next_ready(sc); 839 if (req != NULL) 840 return (req); 841 842 return (vtblk_request_bio(sc)); 843 } 844 845 static struct vtblk_request * 846 vtblk_request_bio(struct vtblk_softc *sc) 847 { 848 struct bio_queue_head *bioq; 849 struct vtblk_request *req; 850 struct bio *bp; 851 852 bioq = &sc->vtblk_bioq; 853 854 if (bioq_first(bioq) == NULL) 855 return (NULL); 856 857 req = vtblk_request_dequeue(sc); 858 if (req == NULL) 859 return (NULL); 860 861 bp = bioq_takefirst(bioq); 862 req->vbr_bp = bp; 863 req->vbr_ack = -1; 864 req->vbr_hdr.ioprio = 1; 865 866 switch (bp->bio_cmd) { 867 case BIO_FLUSH: 868 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 869 break; 870 case BIO_READ: 871 req->vbr_hdr.type = VIRTIO_BLK_T_IN; 872 req->vbr_hdr.sector = bp->bio_offset / 512; 873 break; 874 case BIO_WRITE: 875 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 876 req->vbr_hdr.sector = bp->bio_offset / 512; 877 break; 878 default: 879 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 880 } 881 882 if (bp->bio_flags & BIO_ORDERED) 883 req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER; 884 885 return (req); 886 } 887 888 static int 889 vtblk_request_execute(struct vtblk_softc *sc, struct vtblk_request *req) 890 { 891 struct virtqueue *vq; 892 struct sglist *sg; 893 struct bio *bp; 894 int ordered, readable, writable, error; 895 896 vq = sc->vtblk_vq; 897 sg = sc->vtblk_sglist; 898 bp = req->vbr_bp; 899 ordered = 0; 900 writable = 0; 901 902 /* 903 * Some hosts (such as bhyve) do not implement the barrier feature, 904 * so we emulate it in the driver by allowing the barrier request 905 * to be the only one in flight. 906 */ 907 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 908 if (sc->vtblk_req_ordered != NULL) 909 return (EBUSY); 910 if (bp->bio_flags & BIO_ORDERED) { 911 if (!virtqueue_empty(vq)) 912 return (EBUSY); 913 ordered = 1; 914 req->vbr_hdr.type &= ~VIRTIO_BLK_T_BARRIER; 915 } 916 } 917 918 sglist_reset(sg); 919 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 920 921 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 922 error = sglist_append_bio(sg, bp); 923 if (error || sg->sg_nseg == sg->sg_maxseg) { 924 panic("%s: bio %p data buffer too big %d", 925 __func__, bp, error); 926 } 927 928 /* BIO_READ means the host writes into our buffer. */ 929 if (bp->bio_cmd == BIO_READ) 930 writable = sg->sg_nseg - 1; 931 } 932 933 writable++; 934 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 935 readable = sg->sg_nseg - writable; 936 937 error = virtqueue_enqueue(vq, req, sg, readable, writable); 938 if (error == 0 && ordered) 939 sc->vtblk_req_ordered = req; 940 941 return (error); 942 } 943 944 static int 945 vtblk_request_error(struct vtblk_request *req) 946 { 947 int error; 948 949 switch (req->vbr_ack) { 950 case VIRTIO_BLK_S_OK: 951 error = 0; 952 break; 953 case VIRTIO_BLK_S_UNSUPP: 954 error = ENOTSUP; 955 break; 956 default: 957 error = EIO; 958 break; 959 } 960 961 return (error); 962 } 963 964 static void 965 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 966 { 967 struct vtblk_request *req; 968 struct bio *bp; 969 970 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 971 if (sc->vtblk_req_ordered != NULL) { 972 MPASS(sc->vtblk_req_ordered == req); 973 sc->vtblk_req_ordered = NULL; 974 } 975 976 bp = req->vbr_bp; 977 bp->bio_error = vtblk_request_error(req); 978 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 979 980 vtblk_request_enqueue(sc, req); 981 } 982 } 983 984 static void 985 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 986 { 987 struct bio *bp, *tmp; 988 989 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 990 if (bp->bio_error != 0) 991 disk_err(bp, "hard error", -1, 1); 992 vtblk_bio_done(sc, bp, bp->bio_error); 993 } 994 } 995 996 static void 997 vtblk_drain_vq(struct vtblk_softc *sc) 998 { 999 struct virtqueue *vq; 1000 struct vtblk_request *req; 1001 int last; 1002 1003 vq = sc->vtblk_vq; 1004 last = 0; 1005 1006 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1007 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1008 vtblk_request_enqueue(sc, req); 1009 } 1010 1011 sc->vtblk_req_ordered = NULL; 1012 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1013 } 1014 1015 static void 1016 vtblk_drain(struct vtblk_softc *sc) 1017 { 1018 struct bio_queue queue; 1019 struct bio_queue_head *bioq; 1020 struct vtblk_request *req; 1021 struct bio *bp; 1022 1023 bioq = &sc->vtblk_bioq; 1024 TAILQ_INIT(&queue); 1025 1026 if (sc->vtblk_vq != NULL) { 1027 vtblk_queue_completed(sc, &queue); 1028 vtblk_done_completed(sc, &queue); 1029 1030 vtblk_drain_vq(sc); 1031 } 1032 1033 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1034 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1035 vtblk_request_enqueue(sc, req); 1036 } 1037 1038 while (bioq_first(bioq) != NULL) { 1039 bp = bioq_takefirst(bioq); 1040 vtblk_bio_done(sc, bp, ENXIO); 1041 } 1042 1043 vtblk_request_free(sc); 1044 } 1045 1046 static void 1047 vtblk_startio(struct vtblk_softc *sc) 1048 { 1049 struct virtqueue *vq; 1050 struct vtblk_request *req; 1051 int enq; 1052 1053 VTBLK_LOCK_ASSERT(sc); 1054 vq = sc->vtblk_vq; 1055 enq = 0; 1056 1057 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1058 return; 1059 1060 while (!virtqueue_full(vq)) { 1061 req = vtblk_request_next(sc); 1062 if (req == NULL) 1063 break; 1064 1065 if (vtblk_request_execute(sc, req) != 0) { 1066 vtblk_request_requeue_ready(sc, req); 1067 break; 1068 } 1069 1070 enq++; 1071 } 1072 1073 if (enq > 0) 1074 virtqueue_notify(vq); 1075 } 1076 1077 static void 1078 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1079 { 1080 1081 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1082 if (sc != NULL) 1083 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1084 1085 if (error) { 1086 bp->bio_resid = bp->bio_bcount; 1087 bp->bio_error = error; 1088 bp->bio_flags |= BIO_ERROR; 1089 } 1090 1091 biodone(bp); 1092 } 1093 1094 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1095 if (virtio_with_feature(_dev, _feature)) { \ 1096 virtio_read_device_config(_dev, \ 1097 offsetof(struct virtio_blk_config, _field), \ 1098 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1099 } 1100 1101 static void 1102 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1103 { 1104 device_t dev; 1105 1106 dev = sc->vtblk_dev; 1107 1108 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1109 1110 /* The capacity is always available. */ 1111 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1112 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1113 1114 /* Read the configuration if the feature was negotiated. */ 1115 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1116 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1117 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, geometry, blkcfg); 1118 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1119 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, topology, blkcfg); 1120 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, writeback, blkcfg); 1121 } 1122 1123 #undef VTBLK_GET_CONFIG 1124 1125 static void 1126 vtblk_ident(struct vtblk_softc *sc) 1127 { 1128 struct bio buf; 1129 struct disk *dp; 1130 struct vtblk_request *req; 1131 int len, error; 1132 1133 dp = sc->vtblk_disk; 1134 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1135 1136 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1137 return; 1138 1139 req = vtblk_request_dequeue(sc); 1140 if (req == NULL) 1141 return; 1142 1143 req->vbr_ack = -1; 1144 req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; 1145 req->vbr_hdr.ioprio = 1; 1146 req->vbr_hdr.sector = 0; 1147 1148 req->vbr_bp = &buf; 1149 bzero(&buf, sizeof(struct bio)); 1150 1151 buf.bio_cmd = BIO_READ; 1152 buf.bio_data = dp->d_ident; 1153 buf.bio_bcount = len; 1154 1155 VTBLK_LOCK(sc); 1156 error = vtblk_poll_request(sc, req); 1157 VTBLK_UNLOCK(sc); 1158 1159 vtblk_request_enqueue(sc, req); 1160 1161 if (error) { 1162 device_printf(sc->vtblk_dev, 1163 "error getting device identifier: %d\n", error); 1164 } 1165 } 1166 1167 static int 1168 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1169 { 1170 struct virtqueue *vq; 1171 int error; 1172 1173 vq = sc->vtblk_vq; 1174 1175 if (!virtqueue_empty(vq)) 1176 return (EBUSY); 1177 1178 error = vtblk_request_execute(sc, req); 1179 if (error) 1180 return (error); 1181 1182 virtqueue_notify(vq); 1183 virtqueue_poll(vq, NULL); 1184 1185 error = vtblk_request_error(req); 1186 if (error && bootverbose) { 1187 device_printf(sc->vtblk_dev, 1188 "%s: IO error: %d\n", __func__, error); 1189 } 1190 1191 return (error); 1192 } 1193 1194 static int 1195 vtblk_quiesce(struct vtblk_softc *sc) 1196 { 1197 int error; 1198 1199 VTBLK_LOCK_ASSERT(sc); 1200 error = 0; 1201 1202 while (!virtqueue_empty(sc->vtblk_vq)) { 1203 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1204 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1205 error = EBUSY; 1206 break; 1207 } 1208 } 1209 1210 return (error); 1211 } 1212 1213 static void 1214 vtblk_vq_intr(void *xsc) 1215 { 1216 struct vtblk_softc *sc; 1217 struct virtqueue *vq; 1218 struct bio_queue queue; 1219 1220 sc = xsc; 1221 vq = sc->vtblk_vq; 1222 TAILQ_INIT(&queue); 1223 1224 VTBLK_LOCK(sc); 1225 1226 again: 1227 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1228 goto out; 1229 1230 vtblk_queue_completed(sc, &queue); 1231 vtblk_startio(sc); 1232 1233 if (virtqueue_enable_intr(vq) != 0) { 1234 virtqueue_disable_intr(vq); 1235 goto again; 1236 } 1237 1238 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1239 wakeup(&sc->vtblk_vq); 1240 1241 out: 1242 VTBLK_UNLOCK(sc); 1243 vtblk_done_completed(sc, &queue); 1244 } 1245 1246 static void 1247 vtblk_stop(struct vtblk_softc *sc) 1248 { 1249 1250 virtqueue_disable_intr(sc->vtblk_vq); 1251 virtio_stop(sc->vtblk_dev); 1252 } 1253 1254 static void 1255 vtblk_dump_quiesce(struct vtblk_softc *sc) 1256 { 1257 1258 /* 1259 * Spin here until all the requests in-flight at the time of the 1260 * dump are completed and queued. The queued requests will be 1261 * biodone'd once the dump is finished. 1262 */ 1263 while (!virtqueue_empty(sc->vtblk_vq)) 1264 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1265 } 1266 1267 static int 1268 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1269 size_t length) 1270 { 1271 struct bio buf; 1272 struct vtblk_request *req; 1273 1274 req = &sc->vtblk_dump_request; 1275 req->vbr_ack = -1; 1276 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 1277 req->vbr_hdr.ioprio = 1; 1278 req->vbr_hdr.sector = offset / 512; 1279 1280 req->vbr_bp = &buf; 1281 bzero(&buf, sizeof(struct bio)); 1282 1283 buf.bio_cmd = BIO_WRITE; 1284 buf.bio_data = virtual; 1285 buf.bio_bcount = length; 1286 1287 return (vtblk_poll_request(sc, req)); 1288 } 1289 1290 static int 1291 vtblk_dump_flush(struct vtblk_softc *sc) 1292 { 1293 struct bio buf; 1294 struct vtblk_request *req; 1295 1296 req = &sc->vtblk_dump_request; 1297 req->vbr_ack = -1; 1298 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 1299 req->vbr_hdr.ioprio = 1; 1300 req->vbr_hdr.sector = 0; 1301 1302 req->vbr_bp = &buf; 1303 bzero(&buf, sizeof(struct bio)); 1304 1305 buf.bio_cmd = BIO_FLUSH; 1306 1307 return (vtblk_poll_request(sc, req)); 1308 } 1309 1310 static void 1311 vtblk_dump_complete(struct vtblk_softc *sc) 1312 { 1313 1314 vtblk_dump_flush(sc); 1315 1316 VTBLK_UNLOCK(sc); 1317 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1318 VTBLK_LOCK(sc); 1319 } 1320 1321 static void 1322 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1323 { 1324 1325 /* Set either writeback (1) or writethrough (0) mode. */ 1326 virtio_write_dev_config_1(sc->vtblk_dev, 1327 offsetof(struct virtio_blk_config, writeback), wc); 1328 } 1329 1330 static int 1331 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1332 struct virtio_blk_config *blkcfg) 1333 { 1334 int wc; 1335 1336 if (sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) { 1337 wc = vtblk_tunable_int(sc, "writecache_mode", 1338 vtblk_writecache_mode); 1339 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1340 vtblk_set_write_cache(sc, wc); 1341 else 1342 wc = blkcfg->writeback; 1343 } else 1344 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_WCE); 1345 1346 return (wc); 1347 } 1348 1349 static int 1350 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1351 { 1352 struct vtblk_softc *sc; 1353 int wc, error; 1354 1355 sc = oidp->oid_arg1; 1356 wc = sc->vtblk_write_cache; 1357 1358 error = sysctl_handle_int(oidp, &wc, 0, req); 1359 if (error || req->newptr == NULL) 1360 return (error); 1361 if ((sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) == 0) 1362 return (EPERM); 1363 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1364 return (EINVAL); 1365 1366 VTBLK_LOCK(sc); 1367 sc->vtblk_write_cache = wc; 1368 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1369 VTBLK_UNLOCK(sc); 1370 1371 return (0); 1372 } 1373 1374 static void 1375 vtblk_setup_sysctl(struct vtblk_softc *sc) 1376 { 1377 device_t dev; 1378 struct sysctl_ctx_list *ctx; 1379 struct sysctl_oid *tree; 1380 struct sysctl_oid_list *child; 1381 1382 dev = sc->vtblk_dev; 1383 ctx = device_get_sysctl_ctx(dev); 1384 tree = device_get_sysctl_tree(dev); 1385 child = SYSCTL_CHILDREN(tree); 1386 1387 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1388 CTLTYPE_INT | CTLFLAG_RW, sc, 0, vtblk_write_cache_sysctl, 1389 "I", "Write cache mode (writethrough (0) or writeback (1))"); 1390 } 1391 1392 static int 1393 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1394 { 1395 char path[64]; 1396 1397 snprintf(path, sizeof(path), 1398 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1399 TUNABLE_INT_FETCH(path, &def); 1400 1401 return (def); 1402 } 1403