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 85 struct virtqueue *vtblk_vq; 86 struct sglist *vtblk_sglist; 87 struct disk *vtblk_disk; 88 89 struct bio_queue_head vtblk_bioq; 90 TAILQ_HEAD(, vtblk_request) 91 vtblk_req_free; 92 TAILQ_HEAD(, vtblk_request) 93 vtblk_req_ready; 94 struct vtblk_request *vtblk_req_ordered; 95 96 int vtblk_max_nsegs; 97 int vtblk_request_count; 98 enum vtblk_cache_mode vtblk_write_cache; 99 100 struct bio_queue vtblk_dump_queue; 101 struct vtblk_request vtblk_dump_request; 102 }; 103 104 static struct virtio_feature_desc vtblk_feature_desc[] = { 105 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 106 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 107 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 108 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 109 { VIRTIO_BLK_F_RO, "ReadOnly" }, 110 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 111 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 112 { VIRTIO_BLK_F_WCE, "WriteCache" }, 113 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 114 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, 115 116 { 0, NULL } 117 }; 118 119 static int vtblk_modevent(module_t, int, void *); 120 121 static int vtblk_probe(device_t); 122 static int vtblk_attach(device_t); 123 static int vtblk_detach(device_t); 124 static int vtblk_suspend(device_t); 125 static int vtblk_resume(device_t); 126 static int vtblk_shutdown(device_t); 127 static int vtblk_config_change(device_t); 128 129 static int vtblk_open(struct disk *); 130 static int vtblk_close(struct disk *); 131 static int vtblk_ioctl(struct disk *, u_long, void *, int, 132 struct thread *); 133 static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); 134 static void vtblk_strategy(struct bio *); 135 136 static void vtblk_negotiate_features(struct vtblk_softc *); 137 static void vtblk_setup_features(struct vtblk_softc *); 138 static int vtblk_maximum_segments(struct vtblk_softc *, 139 struct virtio_blk_config *); 140 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 141 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 142 static void vtblk_alloc_disk(struct vtblk_softc *, 143 struct virtio_blk_config *); 144 static void vtblk_create_disk(struct vtblk_softc *); 145 146 static int vtblk_request_prealloc(struct vtblk_softc *); 147 static void vtblk_request_free(struct vtblk_softc *); 148 static struct vtblk_request * 149 vtblk_request_dequeue(struct vtblk_softc *); 150 static void vtblk_request_enqueue(struct vtblk_softc *, 151 struct vtblk_request *); 152 static struct vtblk_request * 153 vtblk_request_next_ready(struct vtblk_softc *); 154 static void vtblk_request_requeue_ready(struct vtblk_softc *, 155 struct vtblk_request *); 156 static struct vtblk_request * 157 vtblk_request_next(struct vtblk_softc *); 158 static struct vtblk_request * 159 vtblk_request_bio(struct vtblk_softc *); 160 static int vtblk_request_execute(struct vtblk_softc *, 161 struct vtblk_request *); 162 static int vtblk_request_error(struct vtblk_request *); 163 164 static void vtblk_queue_completed(struct vtblk_softc *, 165 struct bio_queue *); 166 static void vtblk_done_completed(struct vtblk_softc *, 167 struct bio_queue *); 168 static void vtblk_drain_vq(struct vtblk_softc *); 169 static void vtblk_drain(struct vtblk_softc *); 170 171 static void vtblk_startio(struct vtblk_softc *); 172 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 173 174 static void vtblk_read_config(struct vtblk_softc *, 175 struct virtio_blk_config *); 176 static void vtblk_ident(struct vtblk_softc *); 177 static int vtblk_poll_request(struct vtblk_softc *, 178 struct vtblk_request *); 179 static int vtblk_quiesce(struct vtblk_softc *); 180 static void vtblk_vq_intr(void *); 181 static void vtblk_stop(struct vtblk_softc *); 182 183 static void vtblk_dump_quiesce(struct vtblk_softc *); 184 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 185 static int vtblk_dump_flush(struct vtblk_softc *); 186 static void vtblk_dump_complete(struct vtblk_softc *); 187 188 static void vtblk_set_write_cache(struct vtblk_softc *, int); 189 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 190 struct virtio_blk_config *); 191 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 192 193 static void vtblk_setup_sysctl(struct vtblk_softc *); 194 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 195 196 /* Tunables. */ 197 static int vtblk_no_ident = 0; 198 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 199 static int vtblk_writecache_mode = -1; 200 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 201 202 /* Features desired/implemented by this driver. */ 203 #define VTBLK_FEATURES \ 204 (VIRTIO_BLK_F_BARRIER | \ 205 VIRTIO_BLK_F_SIZE_MAX | \ 206 VIRTIO_BLK_F_SEG_MAX | \ 207 VIRTIO_BLK_F_GEOMETRY | \ 208 VIRTIO_BLK_F_RO | \ 209 VIRTIO_BLK_F_BLK_SIZE | \ 210 VIRTIO_BLK_F_WCE | \ 211 VIRTIO_BLK_F_TOPOLOGY | \ 212 VIRTIO_BLK_F_CONFIG_WCE | \ 213 VIRTIO_RING_F_INDIRECT_DESC) 214 215 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 216 #define VTBLK_LOCK_INIT(_sc, _name) \ 217 mtx_init(VTBLK_MTX((_sc)), (_name), \ 218 "VirtIO Block Lock", MTX_DEF) 219 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 220 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 221 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 222 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 223 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 224 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 225 226 #define VTBLK_DISK_NAME "vtbd" 227 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 228 229 /* 230 * Each block request uses at least two segments - one for the header 231 * and one for the status. 232 */ 233 #define VTBLK_MIN_SEGMENTS 2 234 235 static device_method_t vtblk_methods[] = { 236 /* Device methods. */ 237 DEVMETHOD(device_probe, vtblk_probe), 238 DEVMETHOD(device_attach, vtblk_attach), 239 DEVMETHOD(device_detach, vtblk_detach), 240 DEVMETHOD(device_suspend, vtblk_suspend), 241 DEVMETHOD(device_resume, vtblk_resume), 242 DEVMETHOD(device_shutdown, vtblk_shutdown), 243 244 /* VirtIO methods. */ 245 DEVMETHOD(virtio_config_change, vtblk_config_change), 246 247 DEVMETHOD_END 248 }; 249 250 static driver_t vtblk_driver = { 251 "vtblk", 252 vtblk_methods, 253 sizeof(struct vtblk_softc) 254 }; 255 static devclass_t vtblk_devclass; 256 257 DRIVER_MODULE(virtio_blk, virtio_mmio, vtblk_driver, vtblk_devclass, 258 vtblk_modevent, 0); 259 DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, 260 vtblk_modevent, 0); 261 MODULE_VERSION(virtio_blk, 1); 262 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 263 264 static int 265 vtblk_modevent(module_t mod, int type, void *unused) 266 { 267 int error; 268 269 error = 0; 270 271 switch (type) { 272 case MOD_LOAD: 273 case MOD_QUIESCE: 274 case MOD_UNLOAD: 275 case MOD_SHUTDOWN: 276 break; 277 default: 278 error = EOPNOTSUPP; 279 break; 280 } 281 282 return (error); 283 } 284 285 static int 286 vtblk_probe(device_t dev) 287 { 288 289 if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) 290 return (ENXIO); 291 292 device_set_desc(dev, "VirtIO Block Adapter"); 293 294 return (BUS_PROBE_DEFAULT); 295 } 296 297 static int 298 vtblk_attach(device_t dev) 299 { 300 struct vtblk_softc *sc; 301 struct virtio_blk_config blkcfg; 302 int error; 303 304 virtio_set_feature_desc(dev, vtblk_feature_desc); 305 306 sc = device_get_softc(dev); 307 sc->vtblk_dev = dev; 308 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 309 bioq_init(&sc->vtblk_bioq); 310 TAILQ_INIT(&sc->vtblk_dump_queue); 311 TAILQ_INIT(&sc->vtblk_req_free); 312 TAILQ_INIT(&sc->vtblk_req_ready); 313 314 vtblk_setup_sysctl(sc); 315 vtblk_setup_features(sc); 316 317 vtblk_read_config(sc, &blkcfg); 318 319 /* 320 * With the current sglist(9) implementation, it is not easy 321 * for us to support a maximum segment size as adjacent 322 * segments are coalesced. For now, just make sure it's larger 323 * than the maximum supported transfer size. 324 */ 325 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 326 if (blkcfg.size_max < MAXPHYS) { 327 error = ENOTSUP; 328 device_printf(dev, "host requires unsupported " 329 "maximum segment size feature\n"); 330 goto fail; 331 } 332 } 333 334 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 335 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 336 error = EINVAL; 337 device_printf(dev, "fewer than minimum number of segments " 338 "allowed: %d\n", sc->vtblk_max_nsegs); 339 goto fail; 340 } 341 342 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 343 if (sc->vtblk_sglist == NULL) { 344 error = ENOMEM; 345 device_printf(dev, "cannot allocate sglist\n"); 346 goto fail; 347 } 348 349 error = vtblk_alloc_virtqueue(sc); 350 if (error) { 351 device_printf(dev, "cannot allocate virtqueue\n"); 352 goto fail; 353 } 354 355 error = vtblk_request_prealloc(sc); 356 if (error) { 357 device_printf(dev, "cannot preallocate requests\n"); 358 goto fail; 359 } 360 361 vtblk_alloc_disk(sc, &blkcfg); 362 363 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 364 if (error) { 365 device_printf(dev, "cannot setup virtqueue interrupt\n"); 366 goto fail; 367 } 368 369 vtblk_create_disk(sc); 370 371 virtqueue_enable_intr(sc->vtblk_vq); 372 373 fail: 374 if (error) 375 vtblk_detach(dev); 376 377 return (error); 378 } 379 380 static int 381 vtblk_detach(device_t dev) 382 { 383 struct vtblk_softc *sc; 384 385 sc = device_get_softc(dev); 386 387 VTBLK_LOCK(sc); 388 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 389 if (device_is_attached(dev)) 390 vtblk_stop(sc); 391 VTBLK_UNLOCK(sc); 392 393 vtblk_drain(sc); 394 395 if (sc->vtblk_disk != NULL) { 396 disk_destroy(sc->vtblk_disk); 397 sc->vtblk_disk = NULL; 398 } 399 400 if (sc->vtblk_sglist != NULL) { 401 sglist_free(sc->vtblk_sglist); 402 sc->vtblk_sglist = NULL; 403 } 404 405 VTBLK_LOCK_DESTROY(sc); 406 407 return (0); 408 } 409 410 static int 411 vtblk_suspend(device_t dev) 412 { 413 struct vtblk_softc *sc; 414 int error; 415 416 sc = device_get_softc(dev); 417 418 VTBLK_LOCK(sc); 419 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 420 /* XXX BMV: virtio_stop(), etc needed here? */ 421 error = vtblk_quiesce(sc); 422 if (error) 423 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 424 VTBLK_UNLOCK(sc); 425 426 return (error); 427 } 428 429 static int 430 vtblk_resume(device_t dev) 431 { 432 struct vtblk_softc *sc; 433 434 sc = device_get_softc(dev); 435 436 VTBLK_LOCK(sc); 437 /* XXX BMV: virtio_reinit(), etc needed here? */ 438 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 439 vtblk_startio(sc); 440 VTBLK_UNLOCK(sc); 441 442 return (0); 443 } 444 445 static int 446 vtblk_shutdown(device_t dev) 447 { 448 449 return (0); 450 } 451 452 static int 453 vtblk_config_change(device_t dev) 454 { 455 struct vtblk_softc *sc; 456 struct virtio_blk_config blkcfg; 457 uint64_t capacity; 458 459 sc = device_get_softc(dev); 460 461 vtblk_read_config(sc, &blkcfg); 462 463 /* Capacity is always in 512-byte units. */ 464 capacity = blkcfg.capacity * 512; 465 466 if (sc->vtblk_disk->d_mediasize != capacity) 467 vtblk_resize_disk(sc, capacity); 468 469 return (0); 470 } 471 472 static int 473 vtblk_open(struct disk *dp) 474 { 475 struct vtblk_softc *sc; 476 477 if ((sc = dp->d_drv1) == NULL) 478 return (ENXIO); 479 480 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 481 } 482 483 static int 484 vtblk_close(struct disk *dp) 485 { 486 struct vtblk_softc *sc; 487 488 if ((sc = dp->d_drv1) == NULL) 489 return (ENXIO); 490 491 return (0); 492 } 493 494 static int 495 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 496 struct thread *td) 497 { 498 struct vtblk_softc *sc; 499 500 if ((sc = dp->d_drv1) == NULL) 501 return (ENXIO); 502 503 return (ENOTTY); 504 } 505 506 static int 507 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 508 size_t length) 509 { 510 struct disk *dp; 511 struct vtblk_softc *sc; 512 int error; 513 514 dp = arg; 515 error = 0; 516 517 if ((sc = dp->d_drv1) == NULL) 518 return (ENXIO); 519 520 VTBLK_LOCK(sc); 521 522 vtblk_dump_quiesce(sc); 523 524 if (length > 0) 525 error = vtblk_dump_write(sc, virtual, offset, length); 526 if (error || (virtual == NULL && offset == 0)) 527 vtblk_dump_complete(sc); 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 blkcfg->topology.physical_block_exp > 0) { 718 dp->d_stripesize = dp->d_sectorsize * 719 (1 << blkcfg->topology.physical_block_exp); 720 dp->d_stripeoffset = (dp->d_stripesize - 721 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 722 dp->d_stripesize; 723 } 724 725 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 726 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 727 else 728 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 729 } 730 731 static void 732 vtblk_create_disk(struct vtblk_softc *sc) 733 { 734 struct disk *dp; 735 736 dp = sc->vtblk_disk; 737 738 vtblk_ident(sc); 739 740 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 741 (uintmax_t) dp->d_mediasize >> 20, 742 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 743 dp->d_sectorsize); 744 745 disk_create(dp, DISK_VERSION); 746 } 747 748 static int 749 vtblk_request_prealloc(struct vtblk_softc *sc) 750 { 751 struct vtblk_request *req; 752 int i, nreqs; 753 754 nreqs = virtqueue_size(sc->vtblk_vq); 755 756 /* 757 * Preallocate sufficient requests to keep the virtqueue full. Each 758 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 759 * the number allocated when indirect descriptors are not available. 760 */ 761 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 762 nreqs /= VTBLK_MIN_SEGMENTS; 763 764 for (i = 0; i < nreqs; i++) { 765 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 766 if (req == NULL) 767 return (ENOMEM); 768 769 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 770 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 771 772 sc->vtblk_request_count++; 773 vtblk_request_enqueue(sc, req); 774 } 775 776 return (0); 777 } 778 779 static void 780 vtblk_request_free(struct vtblk_softc *sc) 781 { 782 struct vtblk_request *req; 783 784 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 785 786 while ((req = vtblk_request_dequeue(sc)) != NULL) { 787 sc->vtblk_request_count--; 788 free(req, M_DEVBUF); 789 } 790 791 KASSERT(sc->vtblk_request_count == 0, 792 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 793 } 794 795 static struct vtblk_request * 796 vtblk_request_dequeue(struct vtblk_softc *sc) 797 { 798 struct vtblk_request *req; 799 800 req = TAILQ_FIRST(&sc->vtblk_req_free); 801 if (req != NULL) { 802 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 803 bzero(req, sizeof(struct vtblk_request)); 804 } 805 806 return (req); 807 } 808 809 static void 810 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 811 { 812 813 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 814 } 815 816 static struct vtblk_request * 817 vtblk_request_next_ready(struct vtblk_softc *sc) 818 { 819 struct vtblk_request *req; 820 821 req = TAILQ_FIRST(&sc->vtblk_req_ready); 822 if (req != NULL) 823 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 824 825 return (req); 826 } 827 828 static void 829 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 830 { 831 832 /* NOTE: Currently, there will be at most one request in the queue. */ 833 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 834 } 835 836 static struct vtblk_request * 837 vtblk_request_next(struct vtblk_softc *sc) 838 { 839 struct vtblk_request *req; 840 841 req = vtblk_request_next_ready(sc); 842 if (req != NULL) 843 return (req); 844 845 return (vtblk_request_bio(sc)); 846 } 847 848 static struct vtblk_request * 849 vtblk_request_bio(struct vtblk_softc *sc) 850 { 851 struct bio_queue_head *bioq; 852 struct vtblk_request *req; 853 struct bio *bp; 854 855 bioq = &sc->vtblk_bioq; 856 857 if (bioq_first(bioq) == NULL) 858 return (NULL); 859 860 req = vtblk_request_dequeue(sc); 861 if (req == NULL) 862 return (NULL); 863 864 bp = bioq_takefirst(bioq); 865 req->vbr_bp = bp; 866 req->vbr_ack = -1; 867 req->vbr_hdr.ioprio = 1; 868 869 switch (bp->bio_cmd) { 870 case BIO_FLUSH: 871 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 872 break; 873 case BIO_READ: 874 req->vbr_hdr.type = VIRTIO_BLK_T_IN; 875 req->vbr_hdr.sector = bp->bio_offset / 512; 876 break; 877 case BIO_WRITE: 878 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 879 req->vbr_hdr.sector = bp->bio_offset / 512; 880 break; 881 default: 882 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 883 } 884 885 if (bp->bio_flags & BIO_ORDERED) 886 req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER; 887 888 return (req); 889 } 890 891 static int 892 vtblk_request_execute(struct vtblk_softc *sc, struct vtblk_request *req) 893 { 894 struct virtqueue *vq; 895 struct sglist *sg; 896 struct bio *bp; 897 int ordered, readable, writable, error; 898 899 vq = sc->vtblk_vq; 900 sg = sc->vtblk_sglist; 901 bp = req->vbr_bp; 902 ordered = 0; 903 writable = 0; 904 905 /* 906 * Some hosts (such as bhyve) do not implement the barrier feature, 907 * so we emulate it in the driver by allowing the barrier request 908 * to be the only one in flight. 909 */ 910 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 911 if (sc->vtblk_req_ordered != NULL) 912 return (EBUSY); 913 if (bp->bio_flags & BIO_ORDERED) { 914 if (!virtqueue_empty(vq)) 915 return (EBUSY); 916 ordered = 1; 917 req->vbr_hdr.type &= ~VIRTIO_BLK_T_BARRIER; 918 } 919 } 920 921 sglist_reset(sg); 922 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 923 924 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 925 error = sglist_append_bio(sg, bp); 926 if (error || sg->sg_nseg == sg->sg_maxseg) { 927 panic("%s: bio %p data buffer too big %d", 928 __func__, bp, error); 929 } 930 931 /* BIO_READ means the host writes into our buffer. */ 932 if (bp->bio_cmd == BIO_READ) 933 writable = sg->sg_nseg - 1; 934 } 935 936 writable++; 937 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 938 readable = sg->sg_nseg - writable; 939 940 error = virtqueue_enqueue(vq, req, sg, readable, writable); 941 if (error == 0 && ordered) 942 sc->vtblk_req_ordered = req; 943 944 return (error); 945 } 946 947 static int 948 vtblk_request_error(struct vtblk_request *req) 949 { 950 int error; 951 952 switch (req->vbr_ack) { 953 case VIRTIO_BLK_S_OK: 954 error = 0; 955 break; 956 case VIRTIO_BLK_S_UNSUPP: 957 error = ENOTSUP; 958 break; 959 default: 960 error = EIO; 961 break; 962 } 963 964 return (error); 965 } 966 967 static void 968 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 969 { 970 struct vtblk_request *req; 971 struct bio *bp; 972 973 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 974 if (sc->vtblk_req_ordered != NULL) { 975 MPASS(sc->vtblk_req_ordered == req); 976 sc->vtblk_req_ordered = NULL; 977 } 978 979 bp = req->vbr_bp; 980 bp->bio_error = vtblk_request_error(req); 981 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 982 983 vtblk_request_enqueue(sc, req); 984 } 985 } 986 987 static void 988 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 989 { 990 struct bio *bp, *tmp; 991 992 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 993 if (bp->bio_error != 0) 994 disk_err(bp, "hard error", -1, 1); 995 vtblk_bio_done(sc, bp, bp->bio_error); 996 } 997 } 998 999 static void 1000 vtblk_drain_vq(struct vtblk_softc *sc) 1001 { 1002 struct virtqueue *vq; 1003 struct vtblk_request *req; 1004 int last; 1005 1006 vq = sc->vtblk_vq; 1007 last = 0; 1008 1009 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1010 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1011 vtblk_request_enqueue(sc, req); 1012 } 1013 1014 sc->vtblk_req_ordered = NULL; 1015 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1016 } 1017 1018 static void 1019 vtblk_drain(struct vtblk_softc *sc) 1020 { 1021 struct bio_queue queue; 1022 struct bio_queue_head *bioq; 1023 struct vtblk_request *req; 1024 struct bio *bp; 1025 1026 bioq = &sc->vtblk_bioq; 1027 TAILQ_INIT(&queue); 1028 1029 if (sc->vtblk_vq != NULL) { 1030 vtblk_queue_completed(sc, &queue); 1031 vtblk_done_completed(sc, &queue); 1032 1033 vtblk_drain_vq(sc); 1034 } 1035 1036 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1037 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1038 vtblk_request_enqueue(sc, req); 1039 } 1040 1041 while (bioq_first(bioq) != NULL) { 1042 bp = bioq_takefirst(bioq); 1043 vtblk_bio_done(sc, bp, ENXIO); 1044 } 1045 1046 vtblk_request_free(sc); 1047 } 1048 1049 static void 1050 vtblk_startio(struct vtblk_softc *sc) 1051 { 1052 struct virtqueue *vq; 1053 struct vtblk_request *req; 1054 int enq; 1055 1056 VTBLK_LOCK_ASSERT(sc); 1057 vq = sc->vtblk_vq; 1058 enq = 0; 1059 1060 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1061 return; 1062 1063 while (!virtqueue_full(vq)) { 1064 req = vtblk_request_next(sc); 1065 if (req == NULL) 1066 break; 1067 1068 if (vtblk_request_execute(sc, req) != 0) { 1069 vtblk_request_requeue_ready(sc, req); 1070 break; 1071 } 1072 1073 enq++; 1074 } 1075 1076 if (enq > 0) 1077 virtqueue_notify(vq); 1078 } 1079 1080 static void 1081 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1082 { 1083 1084 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1085 if (sc != NULL) 1086 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1087 1088 if (error) { 1089 bp->bio_resid = bp->bio_bcount; 1090 bp->bio_error = error; 1091 bp->bio_flags |= BIO_ERROR; 1092 } 1093 1094 biodone(bp); 1095 } 1096 1097 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1098 if (virtio_with_feature(_dev, _feature)) { \ 1099 virtio_read_device_config(_dev, \ 1100 offsetof(struct virtio_blk_config, _field), \ 1101 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1102 } 1103 1104 static void 1105 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1106 { 1107 device_t dev; 1108 1109 dev = sc->vtblk_dev; 1110 1111 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1112 1113 /* The capacity is always available. */ 1114 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1115 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1116 1117 /* Read the configuration if the feature was negotiated. */ 1118 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1119 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1120 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, geometry, blkcfg); 1121 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1122 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, topology, blkcfg); 1123 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, writeback, blkcfg); 1124 } 1125 1126 #undef VTBLK_GET_CONFIG 1127 1128 static void 1129 vtblk_ident(struct vtblk_softc *sc) 1130 { 1131 struct bio buf; 1132 struct disk *dp; 1133 struct vtblk_request *req; 1134 int len, error; 1135 1136 dp = sc->vtblk_disk; 1137 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1138 1139 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1140 return; 1141 1142 req = vtblk_request_dequeue(sc); 1143 if (req == NULL) 1144 return; 1145 1146 req->vbr_ack = -1; 1147 req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; 1148 req->vbr_hdr.ioprio = 1; 1149 req->vbr_hdr.sector = 0; 1150 1151 req->vbr_bp = &buf; 1152 g_reset_bio(&buf); 1153 1154 buf.bio_cmd = BIO_READ; 1155 buf.bio_data = dp->d_ident; 1156 buf.bio_bcount = len; 1157 1158 VTBLK_LOCK(sc); 1159 error = vtblk_poll_request(sc, req); 1160 VTBLK_UNLOCK(sc); 1161 1162 vtblk_request_enqueue(sc, req); 1163 1164 if (error) { 1165 device_printf(sc->vtblk_dev, 1166 "error getting device identifier: %d\n", error); 1167 } 1168 } 1169 1170 static int 1171 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1172 { 1173 struct virtqueue *vq; 1174 int error; 1175 1176 vq = sc->vtblk_vq; 1177 1178 if (!virtqueue_empty(vq)) 1179 return (EBUSY); 1180 1181 error = vtblk_request_execute(sc, req); 1182 if (error) 1183 return (error); 1184 1185 virtqueue_notify(vq); 1186 virtqueue_poll(vq, NULL); 1187 1188 error = vtblk_request_error(req); 1189 if (error && bootverbose) { 1190 device_printf(sc->vtblk_dev, 1191 "%s: IO error: %d\n", __func__, error); 1192 } 1193 1194 return (error); 1195 } 1196 1197 static int 1198 vtblk_quiesce(struct vtblk_softc *sc) 1199 { 1200 int error; 1201 1202 VTBLK_LOCK_ASSERT(sc); 1203 error = 0; 1204 1205 while (!virtqueue_empty(sc->vtblk_vq)) { 1206 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1207 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1208 error = EBUSY; 1209 break; 1210 } 1211 } 1212 1213 return (error); 1214 } 1215 1216 static void 1217 vtblk_vq_intr(void *xsc) 1218 { 1219 struct vtblk_softc *sc; 1220 struct virtqueue *vq; 1221 struct bio_queue queue; 1222 1223 sc = xsc; 1224 vq = sc->vtblk_vq; 1225 TAILQ_INIT(&queue); 1226 1227 VTBLK_LOCK(sc); 1228 1229 again: 1230 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1231 goto out; 1232 1233 vtblk_queue_completed(sc, &queue); 1234 vtblk_startio(sc); 1235 1236 if (virtqueue_enable_intr(vq) != 0) { 1237 virtqueue_disable_intr(vq); 1238 goto again; 1239 } 1240 1241 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1242 wakeup(&sc->vtblk_vq); 1243 1244 out: 1245 VTBLK_UNLOCK(sc); 1246 vtblk_done_completed(sc, &queue); 1247 } 1248 1249 static void 1250 vtblk_stop(struct vtblk_softc *sc) 1251 { 1252 1253 virtqueue_disable_intr(sc->vtblk_vq); 1254 virtio_stop(sc->vtblk_dev); 1255 } 1256 1257 static void 1258 vtblk_dump_quiesce(struct vtblk_softc *sc) 1259 { 1260 1261 /* 1262 * Spin here until all the requests in-flight at the time of the 1263 * dump are completed and queued. The queued requests will be 1264 * biodone'd once the dump is finished. 1265 */ 1266 while (!virtqueue_empty(sc->vtblk_vq)) 1267 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1268 } 1269 1270 static int 1271 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1272 size_t length) 1273 { 1274 struct bio buf; 1275 struct vtblk_request *req; 1276 1277 req = &sc->vtblk_dump_request; 1278 req->vbr_ack = -1; 1279 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 1280 req->vbr_hdr.ioprio = 1; 1281 req->vbr_hdr.sector = offset / 512; 1282 1283 req->vbr_bp = &buf; 1284 g_reset_bio(&buf); 1285 1286 buf.bio_cmd = BIO_WRITE; 1287 buf.bio_data = virtual; 1288 buf.bio_bcount = length; 1289 1290 return (vtblk_poll_request(sc, req)); 1291 } 1292 1293 static int 1294 vtblk_dump_flush(struct vtblk_softc *sc) 1295 { 1296 struct bio buf; 1297 struct vtblk_request *req; 1298 1299 req = &sc->vtblk_dump_request; 1300 req->vbr_ack = -1; 1301 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 1302 req->vbr_hdr.ioprio = 1; 1303 req->vbr_hdr.sector = 0; 1304 1305 req->vbr_bp = &buf; 1306 g_reset_bio(&buf); 1307 1308 buf.bio_cmd = BIO_FLUSH; 1309 1310 return (vtblk_poll_request(sc, req)); 1311 } 1312 1313 static void 1314 vtblk_dump_complete(struct vtblk_softc *sc) 1315 { 1316 1317 vtblk_dump_flush(sc); 1318 1319 VTBLK_UNLOCK(sc); 1320 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1321 VTBLK_LOCK(sc); 1322 } 1323 1324 static void 1325 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1326 { 1327 1328 /* Set either writeback (1) or writethrough (0) mode. */ 1329 virtio_write_dev_config_1(sc->vtblk_dev, 1330 offsetof(struct virtio_blk_config, writeback), wc); 1331 } 1332 1333 static int 1334 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1335 struct virtio_blk_config *blkcfg) 1336 { 1337 int wc; 1338 1339 if (sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) { 1340 wc = vtblk_tunable_int(sc, "writecache_mode", 1341 vtblk_writecache_mode); 1342 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1343 vtblk_set_write_cache(sc, wc); 1344 else 1345 wc = blkcfg->writeback; 1346 } else 1347 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_WCE); 1348 1349 return (wc); 1350 } 1351 1352 static int 1353 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1354 { 1355 struct vtblk_softc *sc; 1356 int wc, error; 1357 1358 sc = oidp->oid_arg1; 1359 wc = sc->vtblk_write_cache; 1360 1361 error = sysctl_handle_int(oidp, &wc, 0, req); 1362 if (error || req->newptr == NULL) 1363 return (error); 1364 if ((sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) == 0) 1365 return (EPERM); 1366 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1367 return (EINVAL); 1368 1369 VTBLK_LOCK(sc); 1370 sc->vtblk_write_cache = wc; 1371 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1372 VTBLK_UNLOCK(sc); 1373 1374 return (0); 1375 } 1376 1377 static void 1378 vtblk_setup_sysctl(struct vtblk_softc *sc) 1379 { 1380 device_t dev; 1381 struct sysctl_ctx_list *ctx; 1382 struct sysctl_oid *tree; 1383 struct sysctl_oid_list *child; 1384 1385 dev = sc->vtblk_dev; 1386 ctx = device_get_sysctl_ctx(dev); 1387 tree = device_get_sysctl_tree(dev); 1388 child = SYSCTL_CHILDREN(tree); 1389 1390 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1391 CTLTYPE_INT | CTLFLAG_RW, sc, 0, vtblk_write_cache_sysctl, 1392 "I", "Write cache mode (writethrough (0) or writeback (1))"); 1393 } 1394 1395 static int 1396 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1397 { 1398 char path[64]; 1399 1400 snprintf(path, sizeof(path), 1401 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1402 TUNABLE_INT_FETCH(path, &def); 1403 1404 return (def); 1405 } 1406