virtio_blk.c revision 276487
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: stable/10/sys/dev/virtio/block/virtio_blk.c 276487 2015-01-01 01:43:00Z bryanv $"); 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 57struct 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 64enum vtblk_cache_mode { 65 VTBLK_CACHE_WRITETHROUGH, 66 VTBLK_CACHE_WRITEBACK, 67 VTBLK_CACHE_MAX 68}; 69 70struct 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 101static 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 116static int vtblk_modevent(module_t, int, void *); 117 118static int vtblk_probe(device_t); 119static int vtblk_attach(device_t); 120static int vtblk_detach(device_t); 121static int vtblk_suspend(device_t); 122static int vtblk_resume(device_t); 123static int vtblk_shutdown(device_t); 124static int vtblk_config_change(device_t); 125 126static int vtblk_open(struct disk *); 127static int vtblk_close(struct disk *); 128static int vtblk_ioctl(struct disk *, u_long, void *, int, 129 struct thread *); 130static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); 131static void vtblk_strategy(struct bio *); 132 133static void vtblk_negotiate_features(struct vtblk_softc *); 134static void vtblk_setup_features(struct vtblk_softc *); 135static int vtblk_maximum_segments(struct vtblk_softc *, 136 struct virtio_blk_config *); 137static int vtblk_alloc_virtqueue(struct vtblk_softc *); 138static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 139static void vtblk_alloc_disk(struct vtblk_softc *, 140 struct virtio_blk_config *); 141static void vtblk_create_disk(struct vtblk_softc *); 142 143static int vtblk_request_prealloc(struct vtblk_softc *); 144static void vtblk_request_free(struct vtblk_softc *); 145static struct vtblk_request * 146 vtblk_request_dequeue(struct vtblk_softc *); 147static void vtblk_request_enqueue(struct vtblk_softc *, 148 struct vtblk_request *); 149static struct vtblk_request * 150 vtblk_request_next_ready(struct vtblk_softc *); 151static void vtblk_request_requeue_ready(struct vtblk_softc *, 152 struct vtblk_request *); 153static struct vtblk_request * 154 vtblk_request_next(struct vtblk_softc *); 155static struct vtblk_request * 156 vtblk_request_bio(struct vtblk_softc *); 157static int vtblk_request_execute(struct vtblk_softc *, 158 struct vtblk_request *); 159static int vtblk_request_error(struct vtblk_request *); 160 161static void vtblk_queue_completed(struct vtblk_softc *, 162 struct bio_queue *); 163static void vtblk_done_completed(struct vtblk_softc *, 164 struct bio_queue *); 165static void vtblk_drain_vq(struct vtblk_softc *, int); 166static void vtblk_drain(struct vtblk_softc *); 167 168static void vtblk_startio(struct vtblk_softc *); 169static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 170 171static void vtblk_read_config(struct vtblk_softc *, 172 struct virtio_blk_config *); 173static void vtblk_ident(struct vtblk_softc *); 174static int vtblk_poll_request(struct vtblk_softc *, 175 struct vtblk_request *); 176static int vtblk_quiesce(struct vtblk_softc *); 177static void vtblk_vq_intr(void *); 178static void vtblk_stop(struct vtblk_softc *); 179 180static void vtblk_dump_prepare(struct vtblk_softc *); 181static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 182static int vtblk_dump_flush(struct vtblk_softc *); 183 184static void vtblk_set_write_cache(struct vtblk_softc *, int); 185static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 186 struct virtio_blk_config *); 187static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 188 189static void vtblk_setup_sysctl(struct vtblk_softc *); 190static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 191 192/* Tunables. */ 193static int vtblk_no_ident = 0; 194TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 195static int vtblk_writecache_mode = -1; 196TUNABLE_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 230static 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 245static driver_t vtblk_driver = { 246 "vtblk", 247 vtblk_methods, 248 sizeof(struct vtblk_softc) 249}; 250static devclass_t vtblk_devclass; 251 252DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, 253 vtblk_modevent, 0); 254MODULE_VERSION(virtio_blk, 1); 255MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 256 257static int 258vtblk_modevent(module_t mod, int type, void *unused) 259{ 260 int error; 261 262 error = 0; 263 264 switch (type) { 265 case MOD_LOAD: 266 case MOD_QUIESCE: 267 case MOD_UNLOAD: 268 case MOD_SHUTDOWN: 269 break; 270 default: 271 error = EOPNOTSUPP; 272 break; 273 } 274 275 return (error); 276} 277 278static int 279vtblk_probe(device_t dev) 280{ 281 282 if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) 283 return (ENXIO); 284 285 device_set_desc(dev, "VirtIO Block Adapter"); 286 287 return (BUS_PROBE_DEFAULT); 288} 289 290static int 291vtblk_attach(device_t dev) 292{ 293 struct vtblk_softc *sc; 294 struct virtio_blk_config blkcfg; 295 int error; 296 297 virtio_set_feature_desc(dev, vtblk_feature_desc); 298 299 sc = device_get_softc(dev); 300 sc->vtblk_dev = dev; 301 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 302 bioq_init(&sc->vtblk_bioq); 303 TAILQ_INIT(&sc->vtblk_req_free); 304 TAILQ_INIT(&sc->vtblk_req_ready); 305 306 vtblk_setup_sysctl(sc); 307 vtblk_setup_features(sc); 308 309 vtblk_read_config(sc, &blkcfg); 310 311 /* 312 * With the current sglist(9) implementation, it is not easy 313 * for us to support a maximum segment size as adjacent 314 * segments are coalesced. For now, just make sure it's larger 315 * than the maximum supported transfer size. 316 */ 317 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 318 if (blkcfg.size_max < MAXPHYS) { 319 error = ENOTSUP; 320 device_printf(dev, "host requires unsupported " 321 "maximum segment size feature\n"); 322 goto fail; 323 } 324 } 325 326 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 327 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 328 error = EINVAL; 329 device_printf(dev, "fewer than minimum number of segments " 330 "allowed: %d\n", sc->vtblk_max_nsegs); 331 goto fail; 332 } 333 334 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 335 if (sc->vtblk_sglist == NULL) { 336 error = ENOMEM; 337 device_printf(dev, "cannot allocate sglist\n"); 338 goto fail; 339 } 340 341 error = vtblk_alloc_virtqueue(sc); 342 if (error) { 343 device_printf(dev, "cannot allocate virtqueue\n"); 344 goto fail; 345 } 346 347 error = vtblk_request_prealloc(sc); 348 if (error) { 349 device_printf(dev, "cannot preallocate requests\n"); 350 goto fail; 351 } 352 353 vtblk_alloc_disk(sc, &blkcfg); 354 355 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 356 if (error) { 357 device_printf(dev, "cannot setup virtqueue interrupt\n"); 358 goto fail; 359 } 360 361 vtblk_create_disk(sc); 362 363 virtqueue_enable_intr(sc->vtblk_vq); 364 365fail: 366 if (error) 367 vtblk_detach(dev); 368 369 return (error); 370} 371 372static int 373vtblk_detach(device_t dev) 374{ 375 struct vtblk_softc *sc; 376 377 sc = device_get_softc(dev); 378 379 VTBLK_LOCK(sc); 380 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 381 if (device_is_attached(dev)) 382 vtblk_stop(sc); 383 VTBLK_UNLOCK(sc); 384 385 vtblk_drain(sc); 386 387 if (sc->vtblk_disk != NULL) { 388 disk_destroy(sc->vtblk_disk); 389 sc->vtblk_disk = NULL; 390 } 391 392 if (sc->vtblk_sglist != NULL) { 393 sglist_free(sc->vtblk_sglist); 394 sc->vtblk_sglist = NULL; 395 } 396 397 VTBLK_LOCK_DESTROY(sc); 398 399 return (0); 400} 401 402static int 403vtblk_suspend(device_t dev) 404{ 405 struct vtblk_softc *sc; 406 int error; 407 408 sc = device_get_softc(dev); 409 410 VTBLK_LOCK(sc); 411 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 412 /* XXX BMV: virtio_stop(), etc needed here? */ 413 error = vtblk_quiesce(sc); 414 if (error) 415 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 416 VTBLK_UNLOCK(sc); 417 418 return (error); 419} 420 421static int 422vtblk_resume(device_t dev) 423{ 424 struct vtblk_softc *sc; 425 426 sc = device_get_softc(dev); 427 428 VTBLK_LOCK(sc); 429 /* XXX BMV: virtio_reinit(), etc needed here? */ 430 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 431 vtblk_startio(sc); 432 VTBLK_UNLOCK(sc); 433 434 return (0); 435} 436 437static int 438vtblk_shutdown(device_t dev) 439{ 440 441 return (0); 442} 443 444static int 445vtblk_config_change(device_t dev) 446{ 447 struct vtblk_softc *sc; 448 struct virtio_blk_config blkcfg; 449 uint64_t capacity; 450 451 sc = device_get_softc(dev); 452 453 vtblk_read_config(sc, &blkcfg); 454 455 /* Capacity is always in 512-byte units. */ 456 capacity = blkcfg.capacity * 512; 457 458 if (sc->vtblk_disk->d_mediasize != capacity) 459 vtblk_resize_disk(sc, capacity); 460 461 return (0); 462} 463 464static int 465vtblk_open(struct disk *dp) 466{ 467 struct vtblk_softc *sc; 468 469 if ((sc = dp->d_drv1) == NULL) 470 return (ENXIO); 471 472 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 473} 474 475static int 476vtblk_close(struct disk *dp) 477{ 478 struct vtblk_softc *sc; 479 480 if ((sc = dp->d_drv1) == NULL) 481 return (ENXIO); 482 483 return (0); 484} 485 486static int 487vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 488 struct thread *td) 489{ 490 struct vtblk_softc *sc; 491 492 if ((sc = dp->d_drv1) == NULL) 493 return (ENXIO); 494 495 return (ENOTTY); 496} 497 498static int 499vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 500 size_t length) 501{ 502 struct disk *dp; 503 struct vtblk_softc *sc; 504 int error; 505 506 dp = arg; 507 508 if ((sc = dp->d_drv1) == NULL) 509 return (ENXIO); 510 511 VTBLK_LOCK(sc); 512 513 if ((sc->vtblk_flags & VTBLK_FLAG_DUMPING) == 0) { 514 vtblk_dump_prepare(sc); 515 sc->vtblk_flags |= VTBLK_FLAG_DUMPING; 516 } 517 518 if (length > 0) 519 error = vtblk_dump_write(sc, virtual, offset, length); 520 else if (virtual == NULL && offset == 0) 521 error = vtblk_dump_flush(sc); 522 else { 523 error = EINVAL; 524 sc->vtblk_flags &= ~VTBLK_FLAG_DUMPING; 525 } 526 527 VTBLK_UNLOCK(sc); 528 529 return (error); 530} 531 532static void 533vtblk_strategy(struct bio *bp) 534{ 535 struct vtblk_softc *sc; 536 537 if ((sc = bp->bio_disk->d_drv1) == NULL) { 538 vtblk_bio_done(NULL, bp, EINVAL); 539 return; 540 } 541 542 /* 543 * Fail any write if RO. Unfortunately, there does not seem to 544 * be a better way to report our readonly'ness to GEOM above. 545 */ 546 if (sc->vtblk_flags & VTBLK_FLAG_READONLY && 547 (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_FLUSH)) { 548 vtblk_bio_done(sc, bp, EROFS); 549 return; 550 } 551 552 VTBLK_LOCK(sc); 553 554 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 555 VTBLK_UNLOCK(sc); 556 vtblk_bio_done(sc, bp, ENXIO); 557 return; 558 } 559 560 bioq_insert_tail(&sc->vtblk_bioq, bp); 561 vtblk_startio(sc); 562 563 VTBLK_UNLOCK(sc); 564} 565 566static void 567vtblk_negotiate_features(struct vtblk_softc *sc) 568{ 569 device_t dev; 570 uint64_t features; 571 572 dev = sc->vtblk_dev; 573 features = VTBLK_FEATURES; 574 575 sc->vtblk_features = virtio_negotiate_features(dev, features); 576} 577 578static void 579vtblk_setup_features(struct vtblk_softc *sc) 580{ 581 device_t dev; 582 583 dev = sc->vtblk_dev; 584 585 vtblk_negotiate_features(sc); 586 587 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 588 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 589 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 590 sc->vtblk_flags |= VTBLK_FLAG_READONLY; 591 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 592 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 593 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 594 sc->vtblk_flags |= VTBLK_FLAG_WC_CONFIG; 595} 596 597static int 598vtblk_maximum_segments(struct vtblk_softc *sc, 599 struct virtio_blk_config *blkcfg) 600{ 601 device_t dev; 602 int nsegs; 603 604 dev = sc->vtblk_dev; 605 nsegs = VTBLK_MIN_SEGMENTS; 606 607 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 608 nsegs += MIN(blkcfg->seg_max, MAXPHYS / PAGE_SIZE + 1); 609 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 610 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 611 } else 612 nsegs += 1; 613 614 return (nsegs); 615} 616 617static int 618vtblk_alloc_virtqueue(struct vtblk_softc *sc) 619{ 620 device_t dev; 621 struct vq_alloc_info vq_info; 622 623 dev = sc->vtblk_dev; 624 625 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 626 vtblk_vq_intr, sc, &sc->vtblk_vq, 627 "%s request", device_get_nameunit(dev)); 628 629 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 630} 631 632static void 633vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 634{ 635 device_t dev; 636 struct disk *dp; 637 int error; 638 639 dev = sc->vtblk_dev; 640 dp = sc->vtblk_disk; 641 642 dp->d_mediasize = new_capacity; 643 if (bootverbose) { 644 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 645 (uintmax_t) dp->d_mediasize >> 20, 646 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 647 dp->d_sectorsize); 648 } 649 650 error = disk_resize(dp, M_NOWAIT); 651 if (error) { 652 device_printf(dev, 653 "disk_resize(9) failed, error: %d\n", error); 654 } 655} 656 657static void 658vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 659{ 660 device_t dev; 661 struct disk *dp; 662 663 dev = sc->vtblk_dev; 664 665 sc->vtblk_disk = dp = disk_alloc(); 666 dp->d_open = vtblk_open; 667 dp->d_close = vtblk_close; 668 dp->d_ioctl = vtblk_ioctl; 669 dp->d_strategy = vtblk_strategy; 670 dp->d_name = VTBLK_DISK_NAME; 671 dp->d_unit = device_get_unit(dev); 672 dp->d_drv1 = sc; 673 dp->d_flags = DISKFLAG_CANFLUSHCACHE | DISKFLAG_UNMAPPED_BIO | 674 DISKFLAG_DIRECT_COMPLETION; 675 dp->d_hba_vendor = virtio_get_vendor(dev); 676 dp->d_hba_device = virtio_get_device(dev); 677 dp->d_hba_subvendor = virtio_get_subvendor(dev); 678 dp->d_hba_subdevice = virtio_get_subdevice(dev); 679 680 if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0) 681 dp->d_dump = vtblk_dump; 682 683 /* Capacity is always in 512-byte units. */ 684 dp->d_mediasize = blkcfg->capacity * 512; 685 686 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 687 dp->d_sectorsize = blkcfg->blk_size; 688 else 689 dp->d_sectorsize = 512; 690 691 /* 692 * The VirtIO maximum I/O size is given in terms of segments. 693 * However, FreeBSD limits I/O size by logical buffer size, not 694 * by physically contiguous pages. Therefore, we have to assume 695 * no pages are contiguous. This may impose an artificially low 696 * maximum I/O size. But in practice, since QEMU advertises 128 697 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 698 * which is typically greater than MAXPHYS. Eventually we should 699 * just advertise MAXPHYS and split buffers that are too big. 700 * 701 * Note we must subtract one additional segment in case of non 702 * page aligned buffers. 703 */ 704 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 705 PAGE_SIZE; 706 if (dp->d_maxsize < PAGE_SIZE) 707 dp->d_maxsize = PAGE_SIZE; /* XXX */ 708 709 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 710 dp->d_fwsectors = blkcfg->geometry.sectors; 711 dp->d_fwheads = blkcfg->geometry.heads; 712 } 713 714 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY)) { 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 728static void 729vtblk_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 745static int 746vtblk_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 776static void 777vtblk_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 792static struct vtblk_request * 793vtblk_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 806static void 807vtblk_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 813static struct vtblk_request * 814vtblk_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 825static void 826vtblk_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 833static struct vtblk_request * 834vtblk_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 845static struct vtblk_request * 846vtblk_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 888static int 889vtblk_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 944static int 945vtblk_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 964static void 965vtblk_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 984static void 985vtblk_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 996static void 997vtblk_drain_vq(struct vtblk_softc *sc, int skip_done) 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 if (!skip_done) 1008 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1009 1010 vtblk_request_enqueue(sc, req); 1011 } 1012 1013 sc->vtblk_req_ordered = NULL; 1014 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1015} 1016 1017static void 1018vtblk_drain(struct vtblk_softc *sc) 1019{ 1020 struct bio_queue queue; 1021 struct bio_queue_head *bioq; 1022 struct vtblk_request *req; 1023 struct bio *bp; 1024 1025 bioq = &sc->vtblk_bioq; 1026 TAILQ_INIT(&queue); 1027 1028 if (sc->vtblk_vq != NULL) { 1029 vtblk_queue_completed(sc, &queue); 1030 vtblk_done_completed(sc, &queue); 1031 1032 vtblk_drain_vq(sc, 0); 1033 } 1034 1035 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1036 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1037 vtblk_request_enqueue(sc, req); 1038 } 1039 1040 while (bioq_first(bioq) != NULL) { 1041 bp = bioq_takefirst(bioq); 1042 vtblk_bio_done(sc, bp, ENXIO); 1043 } 1044 1045 vtblk_request_free(sc); 1046} 1047 1048static void 1049vtblk_startio(struct vtblk_softc *sc) 1050{ 1051 struct virtqueue *vq; 1052 struct vtblk_request *req; 1053 int enq; 1054 1055 VTBLK_LOCK_ASSERT(sc); 1056 vq = sc->vtblk_vq; 1057 enq = 0; 1058 1059 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1060 return; 1061 1062 while (!virtqueue_full(vq)) { 1063 req = vtblk_request_next(sc); 1064 if (req == NULL) 1065 break; 1066 1067 if (vtblk_request_execute(sc, req) != 0) { 1068 vtblk_request_requeue_ready(sc, req); 1069 break; 1070 } 1071 1072 enq++; 1073 } 1074 1075 if (enq > 0) 1076 virtqueue_notify(vq); 1077} 1078 1079static void 1080vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1081{ 1082 1083 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1084 if (sc != NULL) 1085 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1086 1087 if (error) { 1088 bp->bio_resid = bp->bio_bcount; 1089 bp->bio_error = error; 1090 bp->bio_flags |= BIO_ERROR; 1091 } 1092 1093 biodone(bp); 1094} 1095 1096#define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1097 if (virtio_with_feature(_dev, _feature)) { \ 1098 virtio_read_device_config(_dev, \ 1099 offsetof(struct virtio_blk_config, _field), \ 1100 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1101 } 1102 1103static void 1104vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1105{ 1106 device_t dev; 1107 1108 dev = sc->vtblk_dev; 1109 1110 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1111 1112 /* The capacity is always available. */ 1113 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1114 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1115 1116 /* Read the configuration if the feature was negotiated. */ 1117 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1118 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1119 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, geometry, blkcfg); 1120 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1121 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, topology, blkcfg); 1122 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, writeback, blkcfg); 1123} 1124 1125#undef VTBLK_GET_CONFIG 1126 1127static void 1128vtblk_ident(struct vtblk_softc *sc) 1129{ 1130 struct bio buf; 1131 struct disk *dp; 1132 struct vtblk_request *req; 1133 int len, error; 1134 1135 dp = sc->vtblk_disk; 1136 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1137 1138 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1139 return; 1140 1141 req = vtblk_request_dequeue(sc); 1142 if (req == NULL) 1143 return; 1144 1145 req->vbr_ack = -1; 1146 req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; 1147 req->vbr_hdr.ioprio = 1; 1148 req->vbr_hdr.sector = 0; 1149 1150 req->vbr_bp = &buf; 1151 bzero(&buf, sizeof(struct bio)); 1152 1153 buf.bio_cmd = BIO_READ; 1154 buf.bio_data = dp->d_ident; 1155 buf.bio_bcount = len; 1156 1157 VTBLK_LOCK(sc); 1158 error = vtblk_poll_request(sc, req); 1159 VTBLK_UNLOCK(sc); 1160 1161 vtblk_request_enqueue(sc, req); 1162 1163 if (error) { 1164 device_printf(sc->vtblk_dev, 1165 "error getting device identifier: %d\n", error); 1166 } 1167} 1168 1169static int 1170vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1171{ 1172 struct virtqueue *vq; 1173 int error; 1174 1175 vq = sc->vtblk_vq; 1176 1177 if (!virtqueue_empty(vq)) 1178 return (EBUSY); 1179 1180 error = vtblk_request_execute(sc, req); 1181 if (error) 1182 return (error); 1183 1184 virtqueue_notify(vq); 1185 virtqueue_poll(vq, NULL); 1186 1187 error = vtblk_request_error(req); 1188 if (error && bootverbose) { 1189 device_printf(sc->vtblk_dev, 1190 "%s: IO error: %d\n", __func__, error); 1191 } 1192 1193 return (error); 1194} 1195 1196static int 1197vtblk_quiesce(struct vtblk_softc *sc) 1198{ 1199 int error; 1200 1201 VTBLK_LOCK_ASSERT(sc); 1202 error = 0; 1203 1204 while (!virtqueue_empty(sc->vtblk_vq)) { 1205 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1206 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1207 error = EBUSY; 1208 break; 1209 } 1210 } 1211 1212 return (error); 1213} 1214 1215static void 1216vtblk_vq_intr(void *xsc) 1217{ 1218 struct vtblk_softc *sc; 1219 struct virtqueue *vq; 1220 struct bio_queue queue; 1221 1222 sc = xsc; 1223 vq = sc->vtblk_vq; 1224 TAILQ_INIT(&queue); 1225 1226 VTBLK_LOCK(sc); 1227 1228again: 1229 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1230 goto out; 1231 1232 vtblk_queue_completed(sc, &queue); 1233 vtblk_startio(sc); 1234 1235 if (virtqueue_enable_intr(vq) != 0) { 1236 virtqueue_disable_intr(vq); 1237 goto again; 1238 } 1239 1240 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1241 wakeup(&sc->vtblk_vq); 1242 1243out: 1244 VTBLK_UNLOCK(sc); 1245 vtblk_done_completed(sc, &queue); 1246} 1247 1248static void 1249vtblk_stop(struct vtblk_softc *sc) 1250{ 1251 1252 virtqueue_disable_intr(sc->vtblk_vq); 1253 virtio_stop(sc->vtblk_dev); 1254} 1255 1256static void 1257vtblk_dump_prepare(struct vtblk_softc *sc) 1258{ 1259 device_t dev; 1260 struct virtqueue *vq; 1261 1262 dev = sc->vtblk_dev; 1263 vq = sc->vtblk_vq; 1264 1265 vtblk_stop(sc); 1266 1267 /* 1268 * Drain all requests caught in-flight in the virtqueue, 1269 * skipping biodone(). When dumping, only one request is 1270 * outstanding at a time, and we just poll the virtqueue 1271 * for the response. 1272 */ 1273 vtblk_drain_vq(sc, 1); 1274 1275 if (virtio_reinit(dev, sc->vtblk_features) != 0) { 1276 panic("%s: cannot reinit VirtIO block device during dump", 1277 device_get_nameunit(dev)); 1278 } 1279 1280 virtqueue_disable_intr(vq); 1281 virtio_reinit_complete(dev); 1282} 1283 1284static int 1285vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1286 size_t length) 1287{ 1288 struct bio buf; 1289 struct vtblk_request *req; 1290 1291 req = &sc->vtblk_dump_request; 1292 req->vbr_ack = -1; 1293 req->vbr_hdr.type = VIRTIO_BLK_T_OUT; 1294 req->vbr_hdr.ioprio = 1; 1295 req->vbr_hdr.sector = offset / 512; 1296 1297 req->vbr_bp = &buf; 1298 bzero(&buf, sizeof(struct bio)); 1299 1300 buf.bio_cmd = BIO_WRITE; 1301 buf.bio_data = virtual; 1302 buf.bio_bcount = length; 1303 1304 return (vtblk_poll_request(sc, req)); 1305} 1306 1307static int 1308vtblk_dump_flush(struct vtblk_softc *sc) 1309{ 1310 struct bio buf; 1311 struct vtblk_request *req; 1312 1313 req = &sc->vtblk_dump_request; 1314 req->vbr_ack = -1; 1315 req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; 1316 req->vbr_hdr.ioprio = 1; 1317 req->vbr_hdr.sector = 0; 1318 1319 req->vbr_bp = &buf; 1320 bzero(&buf, sizeof(struct bio)); 1321 1322 buf.bio_cmd = BIO_FLUSH; 1323 1324 return (vtblk_poll_request(sc, req)); 1325} 1326 1327static void 1328vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1329{ 1330 1331 /* Set either writeback (1) or writethrough (0) mode. */ 1332 virtio_write_dev_config_1(sc->vtblk_dev, 1333 offsetof(struct virtio_blk_config, writeback), wc); 1334} 1335 1336static int 1337vtblk_write_cache_enabled(struct vtblk_softc *sc, 1338 struct virtio_blk_config *blkcfg) 1339{ 1340 int wc; 1341 1342 if (sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) { 1343 wc = vtblk_tunable_int(sc, "writecache_mode", 1344 vtblk_writecache_mode); 1345 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1346 vtblk_set_write_cache(sc, wc); 1347 else 1348 wc = blkcfg->writeback; 1349 } else 1350 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_WCE); 1351 1352 return (wc); 1353} 1354 1355static int 1356vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1357{ 1358 struct vtblk_softc *sc; 1359 int wc, error; 1360 1361 sc = oidp->oid_arg1; 1362 wc = sc->vtblk_write_cache; 1363 1364 error = sysctl_handle_int(oidp, &wc, 0, req); 1365 if (error || req->newptr == NULL) 1366 return (error); 1367 if ((sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) == 0) 1368 return (EPERM); 1369 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1370 return (EINVAL); 1371 1372 VTBLK_LOCK(sc); 1373 sc->vtblk_write_cache = wc; 1374 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1375 VTBLK_UNLOCK(sc); 1376 1377 return (0); 1378} 1379 1380static void 1381vtblk_setup_sysctl(struct vtblk_softc *sc) 1382{ 1383 device_t dev; 1384 struct sysctl_ctx_list *ctx; 1385 struct sysctl_oid *tree; 1386 struct sysctl_oid_list *child; 1387 1388 dev = sc->vtblk_dev; 1389 ctx = device_get_sysctl_ctx(dev); 1390 tree = device_get_sysctl_tree(dev); 1391 child = SYSCTL_CHILDREN(tree); 1392 1393 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1394 CTLTYPE_INT | CTLFLAG_RW, sc, 0, vtblk_write_cache_sysctl, 1395 "I", "Write cache mode (writethrough (0) or writeback (1))"); 1396} 1397 1398static int 1399vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1400{ 1401 char path[64]; 1402 1403 snprintf(path, sizeof(path), 1404 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1405 TUNABLE_INT_FETCH(path, &def); 1406 1407 return (def); 1408} 1409