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_DUMPING 0x0010 80 #define VTBLK_FLAG_BARRIER 0x0020 81 #define VTBLK_FLAG_WC_CONFIG 0x0040 82 83 struct virtqueue *vtblk_vq; 84 struct sglist *vtblk_sglist; 85 struct disk *vtblk_disk; 86 87 struct bio_queue_head vtblk_bioq; 88 TAILQ_HEAD(, vtblk_request) 89 vtblk_req_free; 90 TAILQ_HEAD(, vtblk_request) 91 vtblk_req_ready; 92 struct vtblk_request *vtblk_req_ordered; 93 94 int vtblk_max_nsegs; 95 int vtblk_request_count; 96 enum vtblk_cache_mode vtblk_write_cache; 97 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 *, int); 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_prepare(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 *); 183 184 static void vtblk_set_write_cache(struct vtblk_softc *, int); 185 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 186 struct virtio_blk_config *); 187 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 188 189 static void vtblk_setup_sysctl(struct vtblk_softc *); 190 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 191 192 /* Tunables. */ 193 static int vtblk_no_ident = 0; 194 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 195 static int vtblk_writecache_mode = -1; 196 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 197 198 /* Features desired/implemented by this driver. */ 199 #define VTBLK_FEATURES \ 200 (VIRTIO_BLK_F_BARRIER | \ 201 VIRTIO_BLK_F_SIZE_MAX | \ 202 VIRTIO_BLK_F_SEG_MAX | \ 203 VIRTIO_BLK_F_GEOMETRY | \ 204 VIRTIO_BLK_F_RO | \ 205 VIRTIO_BLK_F_BLK_SIZE | \ 206 VIRTIO_BLK_F_WCE | \ 207 VIRTIO_BLK_F_CONFIG_WCE | \ 208 VIRTIO_RING_F_INDIRECT_DESC) 209 210 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 211 #define VTBLK_LOCK_INIT(_sc, _name) \ 212 mtx_init(VTBLK_MTX((_sc)), (_name), \ 213 "VirtIO Block Lock", MTX_DEF) 214 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 215 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 216 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 217 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 218 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 219 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 220 221 #define VTBLK_DISK_NAME "vtbd" 222 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 223 224 /* 225 * Each block request uses at least two segments - one for the header 226 * and one for the status. 227 */ 228 #define VTBLK_MIN_SEGMENTS 2 229 230 static device_method_t vtblk_methods[] = { 231 /* Device methods. */ 232 DEVMETHOD(device_probe, vtblk_probe), 233 DEVMETHOD(device_attach, vtblk_attach), 234 DEVMETHOD(device_detach, vtblk_detach), 235 DEVMETHOD(device_suspend, vtblk_suspend), 236 DEVMETHOD(device_resume, vtblk_resume), 237 DEVMETHOD(device_shutdown, vtblk_shutdown), 238 239 /* VirtIO methods. */ 240 DEVMETHOD(virtio_config_change, vtblk_config_change), 241 242 DEVMETHOD_END 243 }; 244 245 static driver_t vtblk_driver = { 246 "vtblk", 247 vtblk_methods, 248 sizeof(struct vtblk_softc) 249 }; 250 static devclass_t vtblk_devclass; 251 252 DRIVER_MODULE(virtio_blk, virtio_mmio, vtblk_driver, vtblk_devclass, 253 vtblk_modevent, 0); 254 DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, 255 vtblk_modevent, 0); 256 MODULE_VERSION(virtio_blk, 1); 257 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 258 259 static int 260 vtblk_modevent(module_t mod, int type, void *unused) 261 { 262 int error; 263 264 error = 0; 265 266 switch (type) { 267 case MOD_LOAD: 268 case MOD_QUIESCE: 269 case MOD_UNLOAD: 270 case MOD_SHUTDOWN: 271 break; 272 default: 273 error = EOPNOTSUPP; 274 break; 275 } 276 277 return (error); 278 } 279 280 static int 281 vtblk_probe(device_t dev) 282 { 283 284 if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) 285 return (ENXIO); 286 287 device_set_desc(dev, "VirtIO Block Adapter"); 288 289 return (BUS_PROBE_DEFAULT); 290 } 291 292 static int 293 vtblk_attach(device_t dev) 294 { 295 struct vtblk_softc *sc; 296 struct virtio_blk_config blkcfg; 297 int error; 298 299 virtio_set_feature_desc(dev, vtblk_feature_desc); 300 301 sc = device_get_softc(dev); 302 sc->vtblk_dev = dev; 303 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 304 bioq_init(&sc->vtblk_bioq); 305 TAILQ_INIT(&sc->vtblk_req_free); 306 TAILQ_INIT(&sc->vtblk_req_ready); 307 308 vtblk_setup_sysctl(sc); 309 vtblk_setup_features(sc); 310 311 vtblk_read_config(sc, &blkcfg); 312 313 /* 314 * With the current sglist(9) implementation, it is not easy 315 * for us to support a maximum segment size as adjacent 316 * segments are coalesced. For now, just make sure it's larger 317 * than the maximum supported transfer size. 318 */ 319 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 320 if (blkcfg.size_max < MAXPHYS) { 321 error = ENOTSUP; 322 device_printf(dev, "host requires unsupported " 323 "maximum segment size feature\n"); 324 goto fail; 325 } 326 } 327 328 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 329 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 330 error = EINVAL; 331 device_printf(dev, "fewer than minimum number of segments " 332 "allowed: %d\n", sc->vtblk_max_nsegs); 333 goto fail; 334 } 335 336 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 337 if (sc->vtblk_sglist == NULL) { 338 error = ENOMEM; 339 device_printf(dev, "cannot allocate sglist\n"); 340 goto fail; 341 } 342 343 error = vtblk_alloc_virtqueue(sc); 344 if (error) { 345 device_printf(dev, "cannot allocate virtqueue\n"); 346 goto fail; 347 } 348 349 error = vtblk_request_prealloc(sc); 350 if (error) { 351 device_printf(dev, "cannot preallocate requests\n"); 352 goto fail; 353 } 354 355 vtblk_alloc_disk(sc, &blkcfg); 356 357 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 358 if (error) { 359 device_printf(dev, "cannot setup virtqueue interrupt\n"); 360 goto fail; 361 } 362 363 vtblk_create_disk(sc); 364 365 virtqueue_enable_intr(sc->vtblk_vq); 366 367 fail: 368 if (error) 369 vtblk_detach(dev); 370 371 return (error); 372 } 373 374 static int 375 vtblk_detach(device_t dev) 376 { 377 struct vtblk_softc *sc; 378 379 sc = device_get_softc(dev); 380 381 VTBLK_LOCK(sc); 382 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 383 if (device_is_attached(dev)) 384 vtblk_stop(sc); 385 VTBLK_UNLOCK(sc); 386 387 vtblk_drain(sc); 388 389 if (sc->vtblk_disk != NULL) { 390 disk_destroy(sc->vtblk_disk); 391 sc->vtblk_disk = NULL; 392 } 393 394 if (sc->vtblk_sglist != NULL) { 395 sglist_free(sc->vtblk_sglist); 396 sc->vtblk_sglist = NULL; 397 } 398 399 VTBLK_LOCK_DESTROY(sc); 400 401 return (0); 402 } 403 404 static int 405 vtblk_suspend(device_t dev) 406 { 407 struct vtblk_softc *sc; 408 int error; 409 410 sc = device_get_softc(dev); 411 412 VTBLK_LOCK(sc); 413 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 414 /* XXX BMV: virtio_stop(), etc needed here? */ 415 error = vtblk_quiesce(sc); 416 if (error) 417 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 418 VTBLK_UNLOCK(sc); 419 420 return (error); 421 } 422 423 static int 424 vtblk_resume(device_t dev) 425 { 426 struct vtblk_softc *sc; 427 428 sc = device_get_softc(dev); 429 430 VTBLK_LOCK(sc); 431 /* XXX BMV: virtio_reinit(), etc needed here? */ 432 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 433 vtblk_startio(sc); 434 VTBLK_UNLOCK(sc); 435 436 return (0); 437 } 438 439 static int 440 vtblk_shutdown(device_t dev) 441 { 442 443 return (0); 444 } 445 446 static int 447 vtblk_config_change(device_t dev) 448 { 449 struct vtblk_softc *sc; 450 struct virtio_blk_config blkcfg; 451 uint64_t capacity; 452 453 sc = device_get_softc(dev); 454 455 vtblk_read_config(sc, &blkcfg); 456 457 /* Capacity is always in 512-byte units. */ 458 capacity = blkcfg.capacity * 512; 459 460 if (sc->vtblk_disk->d_mediasize != capacity) 461 vtblk_resize_disk(sc, capacity); 462 463 return (0); 464 } 465 466 static int 467 vtblk_open(struct disk *dp) 468 { 469 struct vtblk_softc *sc; 470 471 if ((sc = dp->d_drv1) == NULL) 472 return (ENXIO); 473 474 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 475 } 476 477 static int 478 vtblk_close(struct disk *dp) 479 { 480 struct vtblk_softc *sc; 481 482 if ((sc = dp->d_drv1) == NULL) 483 return (ENXIO); 484 485 return (0); 486 } 487 488 static int 489 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 490 struct thread *td) 491 { 492 struct vtblk_softc *sc; 493 494 if ((sc = dp->d_drv1) == NULL) 495 return (ENXIO); 496 497 return (ENOTTY); 498 } 499 500 static int 501 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 502 size_t length) 503 { 504 struct disk *dp; 505 struct vtblk_softc *sc; 506 int error; 507 508 dp = arg; 509 510 if ((sc = dp->d_drv1) == NULL) 511 return (ENXIO); 512 513 VTBLK_LOCK(sc); 514 515 if ((sc->vtblk_flags & VTBLK_FLAG_DUMPING) == 0) { 516 vtblk_dump_prepare(sc); 517 sc->vtblk_flags |= VTBLK_FLAG_DUMPING; 518 } 519 520 if (length > 0) 521 error = vtblk_dump_write(sc, virtual, offset, length); 522 else if (virtual == NULL && offset == 0) 523 error = vtblk_dump_flush(sc); 524 else { 525 error = EINVAL; 526 sc->vtblk_flags &= ~VTBLK_FLAG_DUMPING; 527 } 528 529 VTBLK_UNLOCK(sc); 530 531 return (error); 532 } 533 534 static void 535 vtblk_strategy(struct bio *bp) 536 { 537 struct vtblk_softc *sc; 538 539 if ((sc = bp->bio_disk->d_drv1) == NULL) { 540 vtblk_bio_done(NULL, bp, EINVAL); 541 return; 542 } 543 544 /* 545 * Fail any write if RO. Unfortunately, there does not seem to 546 * be a better way to report our readonly'ness to GEOM above. 547 */ 548 if (sc->vtblk_flags & VTBLK_FLAG_READONLY && 549 (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_FLUSH)) { 550 vtblk_bio_done(sc, bp, EROFS); 551 return; 552 } 553 554 VTBLK_LOCK(sc); 555 556 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 557 VTBLK_UNLOCK(sc); 558 vtblk_bio_done(sc, bp, ENXIO); 559 return; 560 } 561 562 bioq_insert_tail(&sc->vtblk_bioq, bp); 563 vtblk_startio(sc); 564 565 VTBLK_UNLOCK(sc); 566 } 567 568 static void 569 vtblk_negotiate_features(struct vtblk_softc *sc) 570 { 571 device_t dev; 572 uint64_t features; 573 574 dev = sc->vtblk_dev; 575 features = VTBLK_FEATURES; 576 577 sc->vtblk_features = virtio_negotiate_features(dev, features); 578 } 579 580 static void 581 vtblk_setup_features(struct vtblk_softc *sc) 582 { 583 device_t dev; 584 585 dev = sc->vtblk_dev; 586 587 vtblk_negotiate_features(sc); 588 589 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 590 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 591 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 592 sc->vtblk_flags |= VTBLK_FLAG_READONLY; 593 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 594 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 595 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 596 sc->vtblk_flags |= VTBLK_FLAG_WC_CONFIG; 597 } 598 599 static int 600 vtblk_maximum_segments(struct vtblk_softc *sc, 601 struct virtio_blk_config *blkcfg) 602 { 603 device_t dev; 604 int nsegs; 605 606 dev = sc->vtblk_dev; 607 nsegs = VTBLK_MIN_SEGMENTS; 608 609 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 610 nsegs += MIN(blkcfg->seg_max, MAXPHYS / PAGE_SIZE + 1); 611 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 612 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 613 } else 614 nsegs += 1; 615 616 return (nsegs); 617 } 618 619 static int 620 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 621 { 622 device_t dev; 623 struct vq_alloc_info vq_info; 624 625 dev = sc->vtblk_dev; 626 627 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 628 vtblk_vq_intr, sc, &sc->vtblk_vq, 629 "%s request", device_get_nameunit(dev)); 630 631 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 632 } 633 634 static void 635 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 636 { 637 device_t dev; 638 struct disk *dp; 639 int error; 640 641 dev = sc->vtblk_dev; 642 dp = sc->vtblk_disk; 643 644 dp->d_mediasize = new_capacity; 645 if (bootverbose) { 646 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 647 (uintmax_t) dp->d_mediasize >> 20, 648 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 649 dp->d_sectorsize); 650 } 651 652 error = disk_resize(dp, M_NOWAIT); 653 if (error) { 654 device_printf(dev, 655 "disk_resize(9) failed, error: %d\n", error); 656 } 657 } 658 659 static void 660 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 661 { 662 device_t dev; 663 struct disk *dp; 664 665 dev = sc->vtblk_dev; 666 667 sc->vtblk_disk = dp = disk_alloc(); 668 dp->d_open = vtblk_open; 669 dp->d_close = vtblk_close; 670 dp->d_ioctl = vtblk_ioctl; 671 dp->d_strategy = vtblk_strategy; 672 dp->d_name = VTBLK_DISK_NAME; 673 dp->d_unit = device_get_unit(dev); 674 dp->d_drv1 = sc; 675 dp->d_flags = DISKFLAG_CANFLUSHCACHE | DISKFLAG_UNMAPPED_BIO | 676 DISKFLAG_DIRECT_COMPLETION; 677 dp->d_hba_vendor = virtio_get_vendor(dev); 678 dp->d_hba_device = virtio_get_device(dev); 679 dp->d_hba_subvendor = virtio_get_subvendor(dev); 680 dp->d_hba_subdevice = virtio_get_subdevice(dev); 681 682 if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0) 683 dp->d_dump = vtblk_dump; 684 685 /* Capacity is always in 512-byte units. */ 686 dp->d_mediasize = blkcfg->capacity * 512; 687 688 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 689 dp->d_sectorsize = blkcfg->blk_size; 690 else 691 dp->d_sectorsize = 512; 692 693 /* 694 * The VirtIO maximum I/O size is given in terms of segments. 695 * However, FreeBSD limits I/O size by logical buffer size, not 696 * by physically contiguous pages. Therefore, we have to assume 697 * no pages are contiguous. This may impose an artificially low 698 * maximum I/O size. But in practice, since QEMU advertises 128 699 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 700 * which is typically greater than MAXPHYS. Eventually we should 701 * just advertise MAXPHYS and split buffers that are too big. 702 * 703 * Note we must subtract one additional segment in case of non 704 * page aligned buffers. 705 */ 706 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 707 PAGE_SIZE; 708 if (dp->d_maxsize < PAGE_SIZE) 709 dp->d_maxsize = PAGE_SIZE; /* XXX */ 710 711 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 712 dp->d_fwsectors = blkcfg->geometry.sectors; 713 dp->d_fwheads = blkcfg->geometry.heads; 714 } 715 716 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY)) { 717 dp->d_stripesize = dp->d_sectorsize * 718 (1 << blkcfg->topology.physical_block_exp); 719 dp->d_stripeoffset = (dp->d_stripesize - 720 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 721 dp->d_stripesize; 722 } 723 724 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 725 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 726 else 727 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 728 } 729 730 static void 731 vtblk_create_disk(struct vtblk_softc *sc) 732 { 733 struct disk *dp; 734 735 dp = sc->vtblk_disk; 736 737 vtblk_ident(sc); 738 739 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 740 (uintmax_t) dp->d_mediasize >> 20, 741 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 742 dp->d_sectorsize); 743 744 disk_create(dp, DISK_VERSION); 745 } 746 747 static int 748 vtblk_request_prealloc(struct vtblk_softc *sc) 749 { 750 struct vtblk_request *req; 751 int i, nreqs; 752 753 nreqs = virtqueue_size(sc->vtblk_vq); 754 755 /* 756 * Preallocate sufficient requests to keep the virtqueue full. Each 757 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 758 * the number allocated when indirect descriptors are not available. 759 */ 760 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 761 nreqs /= VTBLK_MIN_SEGMENTS; 762 763 for (i = 0; i < nreqs; i++) { 764 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 765 if (req == NULL) 766 return (ENOMEM); 767 768 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 769 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 770 771 sc->vtblk_request_count++; 772 vtblk_request_enqueue(sc, req); 773 } 774 775 return (0); 776 } 777 778 static void 779 vtblk_request_free(struct vtblk_softc *sc) 780 { 781 struct vtblk_request *req; 782 783 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 784 785 while ((req = vtblk_request_dequeue(sc)) != NULL) { 786 sc->vtblk_request_count--; 787 free(req, M_DEVBUF); 788 } 789 790 KASSERT(sc->vtblk_request_count == 0, 791 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 792 } 793 794 static struct vtblk_request * 795 vtblk_request_dequeue(struct vtblk_softc *sc) 796 { 797 struct vtblk_request *req; 798 799 req = TAILQ_FIRST(&sc->vtblk_req_free); 800 if (req != NULL) { 801 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 802 bzero(req, sizeof(struct vtblk_request)); 803 } 804 805 return (req); 806 } 807 808 static void 809 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 810 { 811 812 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 813 } 814 815 static struct vtblk_request * 816 vtblk_request_next_ready(struct vtblk_softc *sc) 817 { 818 struct vtblk_request *req; 819 820 req = TAILQ_FIRST(&sc->vtblk_req_ready); 821 if (req != NULL) 822 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 823 824 return (req); 825 } 826 827 static void 828 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 829 { 830 831 /* NOTE: Currently, there will be at most one request in the queue. */ 832 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 833 } 834 835 static struct vtblk_request * 836 vtblk_request_next(struct vtblk_softc *sc) 837 { 838 struct vtblk_request *req; 839 840 req = vtblk_request_next_ready(sc); 841 if (req != NULL) 842 return (req); 843 844 return (vtblk_request_bio(sc)); 845 } 846 847 static struct vtblk_request * 848 vtblk_request_bio(struct vtblk_softc *sc) 849 { 850 struct bio_queue_head *bioq; 851 struct vtblk_request *req; 852 struct bio *bp; 853 854 bioq = &sc->vtblk_bioq; 855 856 if (bioq_first(bioq) == NULL) 857 return (NULL); 858 859 req = vtblk_request_dequeue(sc); 860 if (req == NULL) 861 return (NULL); 862 863 bp = bioq_takefirst(bioq); 864 req->vbr_bp = bp; 865 req->vbr_ack = -1; 866 req->vbr_hdr.ioprio = 1; 867 868 switch (bp->bio_cmd) { 869 case BIO_FLUSH: 870 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 871 break; 872 case BIO_READ: 873 req->vbr_hdr.type = VIRTIO_BLK_T_IN; 874 req->vbr_hdr.sector = bp->bio_offset / 512; 875 break; 876 case BIO_WRITE: 877 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 878 req->vbr_hdr.sector = bp->bio_offset / 512; 879 break; 880 default: 881 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 882 } 883 884 if (bp->bio_flags & BIO_ORDERED) 885 req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER; 886 887 return (req); 888 } 889 890 static int 891 vtblk_request_execute(struct vtblk_softc *sc, struct vtblk_request *req) 892 { 893 struct virtqueue *vq; 894 struct sglist *sg; 895 struct bio *bp; 896 int ordered, readable, writable, error; 897 898 vq = sc->vtblk_vq; 899 sg = sc->vtblk_sglist; 900 bp = req->vbr_bp; 901 ordered = 0; 902 writable = 0; 903 904 /* 905 * Some hosts (such as bhyve) do not implement the barrier feature, 906 * so we emulate it in the driver by allowing the barrier request 907 * to be the only one in flight. 908 */ 909 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 910 if (sc->vtblk_req_ordered != NULL) 911 return (EBUSY); 912 if (bp->bio_flags & BIO_ORDERED) { 913 if (!virtqueue_empty(vq)) 914 return (EBUSY); 915 ordered = 1; 916 req->vbr_hdr.type &= ~VIRTIO_BLK_T_BARRIER; 917 } 918 } 919 920 sglist_reset(sg); 921 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 922 923 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 924 error = sglist_append_bio(sg, bp); 925 if (error || sg->sg_nseg == sg->sg_maxseg) { 926 panic("%s: bio %p data buffer too big %d", 927 __func__, bp, error); 928 } 929 930 /* BIO_READ means the host writes into our buffer. */ 931 if (bp->bio_cmd == BIO_READ) 932 writable = sg->sg_nseg - 1; 933 } 934 935 writable++; 936 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 937 readable = sg->sg_nseg - writable; 938 939 error = virtqueue_enqueue(vq, req, sg, readable, writable); 940 if (error == 0 && ordered) 941 sc->vtblk_req_ordered = req; 942 943 return (error); 944 } 945 946 static int 947 vtblk_request_error(struct vtblk_request *req) 948 { 949 int error; 950 951 switch (req->vbr_ack) { 952 case VIRTIO_BLK_S_OK: 953 error = 0; 954 break; 955 case VIRTIO_BLK_S_UNSUPP: 956 error = ENOTSUP; 957 break; 958 default: 959 error = EIO; 960 break; 961 } 962 963 return (error); 964 } 965 966 static void 967 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 968 { 969 struct vtblk_request *req; 970 struct bio *bp; 971 972 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 973 if (sc->vtblk_req_ordered != NULL) { 974 MPASS(sc->vtblk_req_ordered == req); 975 sc->vtblk_req_ordered = NULL; 976 } 977 978 bp = req->vbr_bp; 979 bp->bio_error = vtblk_request_error(req); 980 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 981 982 vtblk_request_enqueue(sc, req); 983 } 984 } 985 986 static void 987 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 988 { 989 struct bio *bp, *tmp; 990 991 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 992 if (bp->bio_error != 0) 993 disk_err(bp, "hard error", -1, 1); 994 vtblk_bio_done(sc, bp, bp->bio_error); 995 } 996 } 997 998 static void 999 vtblk_drain_vq(struct vtblk_softc *sc, int skip_done) 1000 { 1001 struct virtqueue *vq; 1002 struct vtblk_request *req; 1003 int last; 1004 1005 vq = sc->vtblk_vq; 1006 last = 0; 1007 1008 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1009 if (!skip_done) 1010 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1011 1012 vtblk_request_enqueue(sc, req); 1013 } 1014 1015 sc->vtblk_req_ordered = NULL; 1016 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1017 } 1018 1019 static void 1020 vtblk_drain(struct vtblk_softc *sc) 1021 { 1022 struct bio_queue queue; 1023 struct bio_queue_head *bioq; 1024 struct vtblk_request *req; 1025 struct bio *bp; 1026 1027 bioq = &sc->vtblk_bioq; 1028 TAILQ_INIT(&queue); 1029 1030 if (sc->vtblk_vq != NULL) { 1031 vtblk_queue_completed(sc, &queue); 1032 vtblk_done_completed(sc, &queue); 1033 1034 vtblk_drain_vq(sc, 0); 1035 } 1036 1037 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1038 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1039 vtblk_request_enqueue(sc, req); 1040 } 1041 1042 while (bioq_first(bioq) != NULL) { 1043 bp = bioq_takefirst(bioq); 1044 vtblk_bio_done(sc, bp, ENXIO); 1045 } 1046 1047 vtblk_request_free(sc); 1048 } 1049 1050 static void 1051 vtblk_startio(struct vtblk_softc *sc) 1052 { 1053 struct virtqueue *vq; 1054 struct vtblk_request *req; 1055 int enq; 1056 1057 VTBLK_LOCK_ASSERT(sc); 1058 vq = sc->vtblk_vq; 1059 enq = 0; 1060 1061 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1062 return; 1063 1064 while (!virtqueue_full(vq)) { 1065 req = vtblk_request_next(sc); 1066 if (req == NULL) 1067 break; 1068 1069 if (vtblk_request_execute(sc, req) != 0) { 1070 vtblk_request_requeue_ready(sc, req); 1071 break; 1072 } 1073 1074 enq++; 1075 } 1076 1077 if (enq > 0) 1078 virtqueue_notify(vq); 1079 } 1080 1081 static void 1082 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1083 { 1084 1085 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1086 if (sc != NULL) 1087 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1088 1089 if (error) { 1090 bp->bio_resid = bp->bio_bcount; 1091 bp->bio_error = error; 1092 bp->bio_flags |= BIO_ERROR; 1093 } 1094 1095 biodone(bp); 1096 } 1097 1098 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1099 if (virtio_with_feature(_dev, _feature)) { \ 1100 virtio_read_device_config(_dev, \ 1101 offsetof(struct virtio_blk_config, _field), \ 1102 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1103 } 1104 1105 static void 1106 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1107 { 1108 device_t dev; 1109 1110 dev = sc->vtblk_dev; 1111 1112 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1113 1114 /* The capacity is always available. */ 1115 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1116 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1117 1118 /* Read the configuration if the feature was negotiated. */ 1119 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1120 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1121 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, geometry, blkcfg); 1122 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1123 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, topology, blkcfg); 1124 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, writeback, blkcfg); 1125 } 1126 1127 #undef VTBLK_GET_CONFIG 1128 1129 static void 1130 vtblk_ident(struct vtblk_softc *sc) 1131 { 1132 struct bio buf; 1133 struct disk *dp; 1134 struct vtblk_request *req; 1135 int len, error; 1136 1137 dp = sc->vtblk_disk; 1138 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1139 1140 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1141 return; 1142 1143 req = vtblk_request_dequeue(sc); 1144 if (req == NULL) 1145 return; 1146 1147 req->vbr_ack = -1; 1148 req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; 1149 req->vbr_hdr.ioprio = 1; 1150 req->vbr_hdr.sector = 0; 1151 1152 req->vbr_bp = &buf; 1153 bzero(&buf, sizeof(struct bio)); 1154 1155 buf.bio_cmd = BIO_READ; 1156 buf.bio_data = dp->d_ident; 1157 buf.bio_bcount = len; 1158 1159 VTBLK_LOCK(sc); 1160 error = vtblk_poll_request(sc, req); 1161 VTBLK_UNLOCK(sc); 1162 1163 vtblk_request_enqueue(sc, req); 1164 1165 if (error) { 1166 device_printf(sc->vtblk_dev, 1167 "error getting device identifier: %d\n", error); 1168 } 1169 } 1170 1171 static int 1172 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1173 { 1174 struct virtqueue *vq; 1175 int error; 1176 1177 vq = sc->vtblk_vq; 1178 1179 if (!virtqueue_empty(vq)) 1180 return (EBUSY); 1181 1182 error = vtblk_request_execute(sc, req); 1183 if (error) 1184 return (error); 1185 1186 virtqueue_notify(vq); 1187 virtqueue_poll(vq, NULL); 1188 1189 error = vtblk_request_error(req); 1190 if (error && bootverbose) { 1191 device_printf(sc->vtblk_dev, 1192 "%s: IO error: %d\n", __func__, error); 1193 } 1194 1195 return (error); 1196 } 1197 1198 static int 1199 vtblk_quiesce(struct vtblk_softc *sc) 1200 { 1201 int error; 1202 1203 VTBLK_LOCK_ASSERT(sc); 1204 error = 0; 1205 1206 while (!virtqueue_empty(sc->vtblk_vq)) { 1207 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1208 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1209 error = EBUSY; 1210 break; 1211 } 1212 } 1213 1214 return (error); 1215 } 1216 1217 static void 1218 vtblk_vq_intr(void *xsc) 1219 { 1220 struct vtblk_softc *sc; 1221 struct virtqueue *vq; 1222 struct bio_queue queue; 1223 1224 sc = xsc; 1225 vq = sc->vtblk_vq; 1226 TAILQ_INIT(&queue); 1227 1228 VTBLK_LOCK(sc); 1229 1230 again: 1231 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1232 goto out; 1233 1234 vtblk_queue_completed(sc, &queue); 1235 vtblk_startio(sc); 1236 1237 if (virtqueue_enable_intr(vq) != 0) { 1238 virtqueue_disable_intr(vq); 1239 goto again; 1240 } 1241 1242 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1243 wakeup(&sc->vtblk_vq); 1244 1245 out: 1246 VTBLK_UNLOCK(sc); 1247 vtblk_done_completed(sc, &queue); 1248 } 1249 1250 static void 1251 vtblk_stop(struct vtblk_softc *sc) 1252 { 1253 1254 virtqueue_disable_intr(sc->vtblk_vq); 1255 virtio_stop(sc->vtblk_dev); 1256 } 1257 1258 static void 1259 vtblk_dump_prepare(struct vtblk_softc *sc) 1260 { 1261 device_t dev; 1262 struct virtqueue *vq; 1263 1264 dev = sc->vtblk_dev; 1265 vq = sc->vtblk_vq; 1266 1267 vtblk_stop(sc); 1268 1269 /* 1270 * Drain all requests caught in-flight in the virtqueue, 1271 * skipping biodone(). When dumping, only one request is 1272 * outstanding at a time, and we just poll the virtqueue 1273 * for the response. 1274 */ 1275 vtblk_drain_vq(sc, 1); 1276 1277 if (virtio_reinit(dev, sc->vtblk_features) != 0) { 1278 panic("%s: cannot reinit VirtIO block device during dump", 1279 device_get_nameunit(dev)); 1280 } 1281 1282 virtqueue_disable_intr(vq); 1283 virtio_reinit_complete(dev); 1284 } 1285 1286 static int 1287 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1288 size_t length) 1289 { 1290 struct bio buf; 1291 struct vtblk_request *req; 1292 1293 req = &sc->vtblk_dump_request; 1294 req->vbr_ack = -1; 1295 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 1296 req->vbr_hdr.ioprio = 1; 1297 req->vbr_hdr.sector = offset / 512; 1298 1299 req->vbr_bp = &buf; 1300 bzero(&buf, sizeof(struct bio)); 1301 1302 buf.bio_cmd = BIO_WRITE; 1303 buf.bio_data = virtual; 1304 buf.bio_bcount = length; 1305 1306 return (vtblk_poll_request(sc, req)); 1307 } 1308 1309 static int 1310 vtblk_dump_flush(struct vtblk_softc *sc) 1311 { 1312 struct bio buf; 1313 struct vtblk_request *req; 1314 1315 req = &sc->vtblk_dump_request; 1316 req->vbr_ack = -1; 1317 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 1318 req->vbr_hdr.ioprio = 1; 1319 req->vbr_hdr.sector = 0; 1320 1321 req->vbr_bp = &buf; 1322 bzero(&buf, sizeof(struct bio)); 1323 1324 buf.bio_cmd = BIO_FLUSH; 1325 1326 return (vtblk_poll_request(sc, req)); 1327 } 1328 1329 static void 1330 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1331 { 1332 1333 /* Set either writeback (1) or writethrough (0) mode. */ 1334 virtio_write_dev_config_1(sc->vtblk_dev, 1335 offsetof(struct virtio_blk_config, writeback), wc); 1336 } 1337 1338 static int 1339 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1340 struct virtio_blk_config *blkcfg) 1341 { 1342 int wc; 1343 1344 if (sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) { 1345 wc = vtblk_tunable_int(sc, "writecache_mode", 1346 vtblk_writecache_mode); 1347 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1348 vtblk_set_write_cache(sc, wc); 1349 else 1350 wc = blkcfg->writeback; 1351 } else 1352 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_WCE); 1353 1354 return (wc); 1355 } 1356 1357 static int 1358 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1359 { 1360 struct vtblk_softc *sc; 1361 int wc, error; 1362 1363 sc = oidp->oid_arg1; 1364 wc = sc->vtblk_write_cache; 1365 1366 error = sysctl_handle_int(oidp, &wc, 0, req); 1367 if (error || req->newptr == NULL) 1368 return (error); 1369 if ((sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) == 0) 1370 return (EPERM); 1371 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1372 return (EINVAL); 1373 1374 VTBLK_LOCK(sc); 1375 sc->vtblk_write_cache = wc; 1376 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1377 VTBLK_UNLOCK(sc); 1378 1379 return (0); 1380 } 1381 1382 static void 1383 vtblk_setup_sysctl(struct vtblk_softc *sc) 1384 { 1385 device_t dev; 1386 struct sysctl_ctx_list *ctx; 1387 struct sysctl_oid *tree; 1388 struct sysctl_oid_list *child; 1389 1390 dev = sc->vtblk_dev; 1391 ctx = device_get_sysctl_ctx(dev); 1392 tree = device_get_sysctl_tree(dev); 1393 child = SYSCTL_CHILDREN(tree); 1394 1395 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1396 CTLTYPE_INT | CTLFLAG_RW, sc, 0, vtblk_write_cache_sysctl, 1397 "I", "Write cache mode (writethrough (0) or writeback (1))"); 1398 } 1399 1400 static int 1401 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1402 { 1403 char path[64]; 1404 1405 snprintf(path, sizeof(path), 1406 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1407 TUNABLE_INT_FETCH(path, &def); 1408 1409 return (def); 1410 } 1411