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_DETACH 0x0002 80 #define VTBLK_FLAG_SUSPEND 0x0004 81 #define VTBLK_FLAG_BARRIER 0x0008 82 #define VTBLK_FLAG_WCE_CONFIG 0x0010 83 84 struct virtqueue *vtblk_vq; 85 struct sglist *vtblk_sglist; 86 struct disk *vtblk_disk; 87 88 struct bio_queue_head vtblk_bioq; 89 TAILQ_HEAD(, vtblk_request) 90 vtblk_req_free; 91 TAILQ_HEAD(, vtblk_request) 92 vtblk_req_ready; 93 struct vtblk_request *vtblk_req_ordered; 94 95 int vtblk_max_nsegs; 96 int vtblk_request_count; 97 enum vtblk_cache_mode vtblk_write_cache; 98 99 struct bio_queue vtblk_dump_queue; 100 struct vtblk_request vtblk_dump_request; 101 }; 102 103 static struct virtio_feature_desc vtblk_feature_desc[] = { 104 { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, 105 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, 106 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, 107 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, 108 { VIRTIO_BLK_F_RO, "ReadOnly" }, 109 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, 110 { VIRTIO_BLK_F_SCSI, "SCSICmds" }, 111 { VIRTIO_BLK_F_FLUSH, "FlushCmd" }, 112 { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, 113 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, 114 { VIRTIO_BLK_F_MQ, "Multiqueue" }, 115 { VIRTIO_BLK_F_DISCARD, "Discard" }, 116 { VIRTIO_BLK_F_WRITE_ZEROES, "WriteZeros" }, 117 118 { 0, NULL } 119 }; 120 121 static int vtblk_modevent(module_t, int, void *); 122 123 static int vtblk_probe(device_t); 124 static int vtblk_attach(device_t); 125 static int vtblk_detach(device_t); 126 static int vtblk_suspend(device_t); 127 static int vtblk_resume(device_t); 128 static int vtblk_shutdown(device_t); 129 static int vtblk_attach_completed(device_t); 130 static int vtblk_config_change(device_t); 131 132 static int vtblk_open(struct disk *); 133 static int vtblk_close(struct disk *); 134 static int vtblk_ioctl(struct disk *, u_long, void *, int, 135 struct thread *); 136 static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); 137 static void vtblk_strategy(struct bio *); 138 139 static int vtblk_negotiate_features(struct vtblk_softc *); 140 static int vtblk_setup_features(struct vtblk_softc *); 141 static int vtblk_maximum_segments(struct vtblk_softc *, 142 struct virtio_blk_config *); 143 static int vtblk_alloc_virtqueue(struct vtblk_softc *); 144 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); 145 static void vtblk_alloc_disk(struct vtblk_softc *, 146 struct virtio_blk_config *); 147 static void vtblk_create_disk(struct vtblk_softc *); 148 149 static int vtblk_request_prealloc(struct vtblk_softc *); 150 static void vtblk_request_free(struct vtblk_softc *); 151 static struct vtblk_request * 152 vtblk_request_dequeue(struct vtblk_softc *); 153 static void vtblk_request_enqueue(struct vtblk_softc *, 154 struct vtblk_request *); 155 static struct vtblk_request * 156 vtblk_request_next_ready(struct vtblk_softc *); 157 static void vtblk_request_requeue_ready(struct vtblk_softc *, 158 struct vtblk_request *); 159 static struct vtblk_request * 160 vtblk_request_next(struct vtblk_softc *); 161 static struct vtblk_request * 162 vtblk_request_bio(struct vtblk_softc *); 163 static int vtblk_request_execute(struct vtblk_softc *, 164 struct vtblk_request *); 165 static int vtblk_request_error(struct vtblk_request *); 166 167 static void vtblk_queue_completed(struct vtblk_softc *, 168 struct bio_queue *); 169 static void vtblk_done_completed(struct vtblk_softc *, 170 struct bio_queue *); 171 static void vtblk_drain_vq(struct vtblk_softc *); 172 static void vtblk_drain(struct vtblk_softc *); 173 174 static void vtblk_startio(struct vtblk_softc *); 175 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int); 176 177 static void vtblk_read_config(struct vtblk_softc *, 178 struct virtio_blk_config *); 179 static void vtblk_ident(struct vtblk_softc *); 180 static int vtblk_poll_request(struct vtblk_softc *, 181 struct vtblk_request *); 182 static int vtblk_quiesce(struct vtblk_softc *); 183 static void vtblk_vq_intr(void *); 184 static void vtblk_stop(struct vtblk_softc *); 185 186 static void vtblk_dump_quiesce(struct vtblk_softc *); 187 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t); 188 static int vtblk_dump_flush(struct vtblk_softc *); 189 static void vtblk_dump_complete(struct vtblk_softc *); 190 191 static void vtblk_set_write_cache(struct vtblk_softc *, int); 192 static int vtblk_write_cache_enabled(struct vtblk_softc *sc, 193 struct virtio_blk_config *); 194 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); 195 196 static void vtblk_setup_sysctl(struct vtblk_softc *); 197 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); 198 199 #define vtblk_modern(_sc) (((_sc)->vtblk_features & VIRTIO_F_VERSION_1) != 0) 200 #define vtblk_htog16(_sc, _val) virtio_htog16(vtblk_modern(_sc), _val) 201 #define vtblk_htog32(_sc, _val) virtio_htog32(vtblk_modern(_sc), _val) 202 #define vtblk_htog64(_sc, _val) virtio_htog64(vtblk_modern(_sc), _val) 203 #define vtblk_gtoh16(_sc, _val) virtio_gtoh16(vtblk_modern(_sc), _val) 204 #define vtblk_gtoh32(_sc, _val) virtio_gtoh32(vtblk_modern(_sc), _val) 205 #define vtblk_gtoh64(_sc, _val) virtio_gtoh64(vtblk_modern(_sc), _val) 206 207 /* Tunables. */ 208 static int vtblk_no_ident = 0; 209 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); 210 static int vtblk_writecache_mode = -1; 211 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); 212 213 #define VTBLK_COMMON_FEATURES \ 214 (VIRTIO_BLK_F_SIZE_MAX | \ 215 VIRTIO_BLK_F_SEG_MAX | \ 216 VIRTIO_BLK_F_GEOMETRY | \ 217 VIRTIO_BLK_F_RO | \ 218 VIRTIO_BLK_F_BLK_SIZE | \ 219 VIRTIO_BLK_F_FLUSH | \ 220 VIRTIO_BLK_F_TOPOLOGY | \ 221 VIRTIO_BLK_F_CONFIG_WCE | \ 222 VIRTIO_BLK_F_DISCARD | \ 223 VIRTIO_RING_F_INDIRECT_DESC) 224 225 #define VTBLK_MODERN_FEATURES (VTBLK_COMMON_FEATURES) 226 #define VTBLK_LEGACY_FEATURES (VIRTIO_BLK_F_BARRIER | VTBLK_COMMON_FEATURES) 227 228 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx 229 #define VTBLK_LOCK_INIT(_sc, _name) \ 230 mtx_init(VTBLK_MTX((_sc)), (_name), \ 231 "VirtIO Block Lock", MTX_DEF) 232 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) 233 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) 234 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) 235 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) 236 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ 237 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) 238 239 #define VTBLK_DISK_NAME "vtbd" 240 #define VTBLK_QUIESCE_TIMEOUT (30 * hz) 241 #define VTBLK_BSIZE 512 242 243 /* 244 * Each block request uses at least two segments - one for the header 245 * and one for the status. 246 */ 247 #define VTBLK_MIN_SEGMENTS 2 248 249 static device_method_t vtblk_methods[] = { 250 /* Device methods. */ 251 DEVMETHOD(device_probe, vtblk_probe), 252 DEVMETHOD(device_attach, vtblk_attach), 253 DEVMETHOD(device_detach, vtblk_detach), 254 DEVMETHOD(device_suspend, vtblk_suspend), 255 DEVMETHOD(device_resume, vtblk_resume), 256 DEVMETHOD(device_shutdown, vtblk_shutdown), 257 258 /* VirtIO methods. */ 259 DEVMETHOD(virtio_attach_completed, vtblk_attach_completed), 260 DEVMETHOD(virtio_config_change, vtblk_config_change), 261 262 DEVMETHOD_END 263 }; 264 265 static driver_t vtblk_driver = { 266 "vtblk", 267 vtblk_methods, 268 sizeof(struct vtblk_softc) 269 }; 270 static devclass_t vtblk_devclass; 271 272 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_devclass, 273 vtblk_modevent, 0); 274 MODULE_VERSION(virtio_blk, 1); 275 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); 276 277 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter"); 278 279 static int 280 vtblk_modevent(module_t mod, int type, void *unused) 281 { 282 int error; 283 284 error = 0; 285 286 switch (type) { 287 case MOD_LOAD: 288 case MOD_QUIESCE: 289 case MOD_UNLOAD: 290 case MOD_SHUTDOWN: 291 break; 292 default: 293 error = EOPNOTSUPP; 294 break; 295 } 296 297 return (error); 298 } 299 300 static int 301 vtblk_probe(device_t dev) 302 { 303 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk)); 304 } 305 306 static int 307 vtblk_attach(device_t dev) 308 { 309 struct vtblk_softc *sc; 310 struct virtio_blk_config blkcfg; 311 int error; 312 313 sc = device_get_softc(dev); 314 sc->vtblk_dev = dev; 315 virtio_set_feature_desc(dev, vtblk_feature_desc); 316 317 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); 318 bioq_init(&sc->vtblk_bioq); 319 TAILQ_INIT(&sc->vtblk_dump_queue); 320 TAILQ_INIT(&sc->vtblk_req_free); 321 TAILQ_INIT(&sc->vtblk_req_ready); 322 323 vtblk_setup_sysctl(sc); 324 325 error = vtblk_setup_features(sc); 326 if (error) { 327 device_printf(dev, "cannot setup features\n"); 328 goto fail; 329 } 330 331 vtblk_read_config(sc, &blkcfg); 332 333 /* 334 * With the current sglist(9) implementation, it is not easy 335 * for us to support a maximum segment size as adjacent 336 * segments are coalesced. For now, just make sure it's larger 337 * than the maximum supported transfer size. 338 */ 339 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { 340 if (blkcfg.size_max < maxphys) { 341 error = ENOTSUP; 342 device_printf(dev, "host requires unsupported " 343 "maximum segment size feature\n"); 344 goto fail; 345 } 346 } 347 348 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); 349 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { 350 error = EINVAL; 351 device_printf(dev, "fewer than minimum number of segments " 352 "allowed: %d\n", sc->vtblk_max_nsegs); 353 goto fail; 354 } 355 356 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); 357 if (sc->vtblk_sglist == NULL) { 358 error = ENOMEM; 359 device_printf(dev, "cannot allocate sglist\n"); 360 goto fail; 361 } 362 363 error = vtblk_alloc_virtqueue(sc); 364 if (error) { 365 device_printf(dev, "cannot allocate virtqueue\n"); 366 goto fail; 367 } 368 369 error = vtblk_request_prealloc(sc); 370 if (error) { 371 device_printf(dev, "cannot preallocate requests\n"); 372 goto fail; 373 } 374 375 vtblk_alloc_disk(sc, &blkcfg); 376 377 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); 378 if (error) { 379 device_printf(dev, "cannot setup virtqueue interrupt\n"); 380 goto fail; 381 } 382 383 virtqueue_enable_intr(sc->vtblk_vq); 384 385 fail: 386 if (error) 387 vtblk_detach(dev); 388 389 return (error); 390 } 391 392 static int 393 vtblk_detach(device_t dev) 394 { 395 struct vtblk_softc *sc; 396 397 sc = device_get_softc(dev); 398 399 VTBLK_LOCK(sc); 400 sc->vtblk_flags |= VTBLK_FLAG_DETACH; 401 if (device_is_attached(dev)) 402 vtblk_stop(sc); 403 VTBLK_UNLOCK(sc); 404 405 vtblk_drain(sc); 406 407 if (sc->vtblk_disk != NULL) { 408 disk_destroy(sc->vtblk_disk); 409 sc->vtblk_disk = NULL; 410 } 411 412 if (sc->vtblk_sglist != NULL) { 413 sglist_free(sc->vtblk_sglist); 414 sc->vtblk_sglist = NULL; 415 } 416 417 VTBLK_LOCK_DESTROY(sc); 418 419 return (0); 420 } 421 422 static int 423 vtblk_suspend(device_t dev) 424 { 425 struct vtblk_softc *sc; 426 int error; 427 428 sc = device_get_softc(dev); 429 430 VTBLK_LOCK(sc); 431 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; 432 /* XXX BMV: virtio_stop(), etc needed here? */ 433 error = vtblk_quiesce(sc); 434 if (error) 435 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 436 VTBLK_UNLOCK(sc); 437 438 return (error); 439 } 440 441 static int 442 vtblk_resume(device_t dev) 443 { 444 struct vtblk_softc *sc; 445 446 sc = device_get_softc(dev); 447 448 VTBLK_LOCK(sc); 449 /* XXX BMV: virtio_reinit(), etc needed here? */ 450 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; 451 vtblk_startio(sc); 452 VTBLK_UNLOCK(sc); 453 454 return (0); 455 } 456 457 static int 458 vtblk_shutdown(device_t dev) 459 { 460 461 return (0); 462 } 463 464 static int 465 vtblk_attach_completed(device_t dev) 466 { 467 struct vtblk_softc *sc; 468 469 sc = device_get_softc(dev); 470 471 /* 472 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be 473 * processed after the device acknowledged 474 * VIRTIO_CONFIG_STATUS_DRIVER_OK. 475 */ 476 vtblk_create_disk(sc); 477 return (0); 478 } 479 480 static int 481 vtblk_config_change(device_t dev) 482 { 483 struct vtblk_softc *sc; 484 struct virtio_blk_config blkcfg; 485 uint64_t capacity; 486 487 sc = device_get_softc(dev); 488 489 vtblk_read_config(sc, &blkcfg); 490 491 /* Capacity is always in 512-byte units. */ 492 capacity = blkcfg.capacity * VTBLK_BSIZE; 493 494 if (sc->vtblk_disk->d_mediasize != capacity) 495 vtblk_resize_disk(sc, capacity); 496 497 return (0); 498 } 499 500 static int 501 vtblk_open(struct disk *dp) 502 { 503 struct vtblk_softc *sc; 504 505 if ((sc = dp->d_drv1) == NULL) 506 return (ENXIO); 507 508 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); 509 } 510 511 static int 512 vtblk_close(struct disk *dp) 513 { 514 struct vtblk_softc *sc; 515 516 if ((sc = dp->d_drv1) == NULL) 517 return (ENXIO); 518 519 return (0); 520 } 521 522 static int 523 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, 524 struct thread *td) 525 { 526 struct vtblk_softc *sc; 527 528 if ((sc = dp->d_drv1) == NULL) 529 return (ENXIO); 530 531 return (ENOTTY); 532 } 533 534 static int 535 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, 536 size_t length) 537 { 538 struct disk *dp; 539 struct vtblk_softc *sc; 540 int error; 541 542 dp = arg; 543 error = 0; 544 545 if ((sc = dp->d_drv1) == NULL) 546 return (ENXIO); 547 548 VTBLK_LOCK(sc); 549 550 vtblk_dump_quiesce(sc); 551 552 if (length > 0) 553 error = vtblk_dump_write(sc, virtual, offset, length); 554 if (error || (virtual == NULL && offset == 0)) 555 vtblk_dump_complete(sc); 556 557 VTBLK_UNLOCK(sc); 558 559 return (error); 560 } 561 562 static void 563 vtblk_strategy(struct bio *bp) 564 { 565 struct vtblk_softc *sc; 566 567 if ((sc = bp->bio_disk->d_drv1) == NULL) { 568 vtblk_bio_done(NULL, bp, EINVAL); 569 return; 570 } 571 572 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) && 573 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) { 574 vtblk_bio_done(sc, bp, EOPNOTSUPP); 575 return; 576 } 577 578 VTBLK_LOCK(sc); 579 580 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { 581 VTBLK_UNLOCK(sc); 582 vtblk_bio_done(sc, bp, ENXIO); 583 return; 584 } 585 586 bioq_insert_tail(&sc->vtblk_bioq, bp); 587 vtblk_startio(sc); 588 589 VTBLK_UNLOCK(sc); 590 } 591 592 static int 593 vtblk_negotiate_features(struct vtblk_softc *sc) 594 { 595 device_t dev; 596 uint64_t features; 597 598 dev = sc->vtblk_dev; 599 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES : 600 VTBLK_LEGACY_FEATURES; 601 602 sc->vtblk_features = virtio_negotiate_features(dev, features); 603 return (virtio_finalize_features(dev)); 604 } 605 606 static int 607 vtblk_setup_features(struct vtblk_softc *sc) 608 { 609 device_t dev; 610 int error; 611 612 dev = sc->vtblk_dev; 613 614 error = vtblk_negotiate_features(sc); 615 if (error) 616 return (error); 617 618 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) 619 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; 620 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) 621 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG; 622 623 /* Legacy. */ 624 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) 625 sc->vtblk_flags |= VTBLK_FLAG_BARRIER; 626 627 return (0); 628 } 629 630 static int 631 vtblk_maximum_segments(struct vtblk_softc *sc, 632 struct virtio_blk_config *blkcfg) 633 { 634 device_t dev; 635 int nsegs; 636 637 dev = sc->vtblk_dev; 638 nsegs = VTBLK_MIN_SEGMENTS; 639 640 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { 641 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1); 642 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) 643 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); 644 } else 645 nsegs += 1; 646 647 return (nsegs); 648 } 649 650 static int 651 vtblk_alloc_virtqueue(struct vtblk_softc *sc) 652 { 653 device_t dev; 654 struct vq_alloc_info vq_info; 655 656 dev = sc->vtblk_dev; 657 658 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, 659 vtblk_vq_intr, sc, &sc->vtblk_vq, 660 "%s request", device_get_nameunit(dev)); 661 662 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); 663 } 664 665 static void 666 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) 667 { 668 device_t dev; 669 struct disk *dp; 670 int error; 671 672 dev = sc->vtblk_dev; 673 dp = sc->vtblk_disk; 674 675 dp->d_mediasize = new_capacity; 676 if (bootverbose) { 677 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", 678 (uintmax_t) dp->d_mediasize >> 20, 679 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 680 dp->d_sectorsize); 681 } 682 683 error = disk_resize(dp, M_NOWAIT); 684 if (error) { 685 device_printf(dev, 686 "disk_resize(9) failed, error: %d\n", error); 687 } 688 } 689 690 static void 691 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 692 { 693 device_t dev; 694 struct disk *dp; 695 696 dev = sc->vtblk_dev; 697 698 sc->vtblk_disk = dp = disk_alloc(); 699 dp->d_open = vtblk_open; 700 dp->d_close = vtblk_close; 701 dp->d_ioctl = vtblk_ioctl; 702 dp->d_strategy = vtblk_strategy; 703 dp->d_name = VTBLK_DISK_NAME; 704 dp->d_unit = device_get_unit(dev); 705 dp->d_drv1 = sc; 706 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION; 707 dp->d_hba_vendor = virtio_get_vendor(dev); 708 dp->d_hba_device = virtio_get_device(dev); 709 dp->d_hba_subvendor = virtio_get_subvendor(dev); 710 dp->d_hba_subdevice = virtio_get_subdevice(dev); 711 712 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) 713 dp->d_flags |= DISKFLAG_WRITE_PROTECT; 714 else { 715 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH)) 716 dp->d_flags |= DISKFLAG_CANFLUSHCACHE; 717 dp->d_dump = vtblk_dump; 718 } 719 720 /* Capacity is always in 512-byte units. */ 721 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE; 722 723 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) 724 dp->d_sectorsize = blkcfg->blk_size; 725 else 726 dp->d_sectorsize = VTBLK_BSIZE; 727 728 /* 729 * The VirtIO maximum I/O size is given in terms of segments. 730 * However, FreeBSD limits I/O size by logical buffer size, not 731 * by physically contiguous pages. Therefore, we have to assume 732 * no pages are contiguous. This may impose an artificially low 733 * maximum I/O size. But in practice, since QEMU advertises 128 734 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, 735 * which is typically greater than maxphys. Eventually we should 736 * just advertise maxphys and split buffers that are too big. 737 * 738 * Note we must subtract one additional segment in case of non 739 * page aligned buffers. 740 */ 741 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * 742 PAGE_SIZE; 743 if (dp->d_maxsize < PAGE_SIZE) 744 dp->d_maxsize = PAGE_SIZE; /* XXX */ 745 746 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { 747 dp->d_fwsectors = blkcfg->geometry.sectors; 748 dp->d_fwheads = blkcfg->geometry.heads; 749 } 750 751 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) && 752 blkcfg->topology.physical_block_exp > 0) { 753 dp->d_stripesize = dp->d_sectorsize * 754 (1 << blkcfg->topology.physical_block_exp); 755 dp->d_stripeoffset = (dp->d_stripesize - 756 blkcfg->topology.alignment_offset * dp->d_sectorsize) % 757 dp->d_stripesize; 758 } 759 760 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) { 761 dp->d_flags |= DISKFLAG_CANDELETE; 762 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE; 763 } 764 765 if (vtblk_write_cache_enabled(sc, blkcfg) != 0) 766 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; 767 else 768 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; 769 } 770 771 static void 772 vtblk_create_disk(struct vtblk_softc *sc) 773 { 774 struct disk *dp; 775 776 dp = sc->vtblk_disk; 777 778 vtblk_ident(sc); 779 780 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", 781 (uintmax_t) dp->d_mediasize >> 20, 782 (uintmax_t) dp->d_mediasize / dp->d_sectorsize, 783 dp->d_sectorsize); 784 785 disk_create(dp, DISK_VERSION); 786 } 787 788 static int 789 vtblk_request_prealloc(struct vtblk_softc *sc) 790 { 791 struct vtblk_request *req; 792 int i, nreqs; 793 794 nreqs = virtqueue_size(sc->vtblk_vq); 795 796 /* 797 * Preallocate sufficient requests to keep the virtqueue full. Each 798 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce 799 * the number allocated when indirect descriptors are not available. 800 */ 801 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) 802 nreqs /= VTBLK_MIN_SEGMENTS; 803 804 for (i = 0; i < nreqs; i++) { 805 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); 806 if (req == NULL) 807 return (ENOMEM); 808 809 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1); 810 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1); 811 812 sc->vtblk_request_count++; 813 vtblk_request_enqueue(sc, req); 814 } 815 816 return (0); 817 } 818 819 static void 820 vtblk_request_free(struct vtblk_softc *sc) 821 { 822 struct vtblk_request *req; 823 824 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready)); 825 826 while ((req = vtblk_request_dequeue(sc)) != NULL) { 827 sc->vtblk_request_count--; 828 free(req, M_DEVBUF); 829 } 830 831 KASSERT(sc->vtblk_request_count == 0, 832 ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); 833 } 834 835 static struct vtblk_request * 836 vtblk_request_dequeue(struct vtblk_softc *sc) 837 { 838 struct vtblk_request *req; 839 840 req = TAILQ_FIRST(&sc->vtblk_req_free); 841 if (req != NULL) { 842 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); 843 bzero(req, sizeof(struct vtblk_request)); 844 } 845 846 return (req); 847 } 848 849 static void 850 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req) 851 { 852 853 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); 854 } 855 856 static struct vtblk_request * 857 vtblk_request_next_ready(struct vtblk_softc *sc) 858 { 859 struct vtblk_request *req; 860 861 req = TAILQ_FIRST(&sc->vtblk_req_ready); 862 if (req != NULL) 863 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); 864 865 return (req); 866 } 867 868 static void 869 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req) 870 { 871 872 /* NOTE: Currently, there will be at most one request in the queue. */ 873 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); 874 } 875 876 static struct vtblk_request * 877 vtblk_request_next(struct vtblk_softc *sc) 878 { 879 struct vtblk_request *req; 880 881 req = vtblk_request_next_ready(sc); 882 if (req != NULL) 883 return (req); 884 885 return (vtblk_request_bio(sc)); 886 } 887 888 static struct vtblk_request * 889 vtblk_request_bio(struct vtblk_softc *sc) 890 { 891 struct bio_queue_head *bioq; 892 struct vtblk_request *req; 893 struct bio *bp; 894 895 bioq = &sc->vtblk_bioq; 896 897 if (bioq_first(bioq) == NULL) 898 return (NULL); 899 900 req = vtblk_request_dequeue(sc); 901 if (req == NULL) 902 return (NULL); 903 904 bp = bioq_takefirst(bioq); 905 req->vbr_bp = bp; 906 req->vbr_ack = -1; 907 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 908 909 switch (bp->bio_cmd) { 910 case BIO_FLUSH: 911 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 912 req->vbr_hdr.sector = 0; 913 break; 914 case BIO_READ: 915 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN); 916 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 917 break; 918 case BIO_WRITE: 919 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 920 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 921 break; 922 case BIO_DELETE: 923 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD); 924 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 925 break; 926 default: 927 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); 928 } 929 930 if (bp->bio_flags & BIO_ORDERED) 931 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER); 932 933 return (req); 934 } 935 936 static int 937 vtblk_request_execute(struct vtblk_softc *sc, struct vtblk_request *req) 938 { 939 struct virtqueue *vq; 940 struct sglist *sg; 941 struct bio *bp; 942 int ordered, readable, writable, error; 943 944 vq = sc->vtblk_vq; 945 sg = sc->vtblk_sglist; 946 bp = req->vbr_bp; 947 ordered = 0; 948 writable = 0; 949 950 /* 951 * Some hosts (such as bhyve) do not implement the barrier feature, 952 * so we emulate it in the driver by allowing the barrier request 953 * to be the only one in flight. 954 */ 955 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { 956 if (sc->vtblk_req_ordered != NULL) 957 return (EBUSY); 958 if (bp->bio_flags & BIO_ORDERED) { 959 if (!virtqueue_empty(vq)) 960 return (EBUSY); 961 ordered = 1; 962 req->vbr_hdr.type &= vtblk_gtoh32(sc, 963 ~VIRTIO_BLK_T_BARRIER); 964 } 965 } 966 967 sglist_reset(sg); 968 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); 969 970 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { 971 error = sglist_append_bio(sg, bp); 972 if (error || sg->sg_nseg == sg->sg_maxseg) { 973 panic("%s: bio %p data buffer too big %d", 974 __func__, bp, error); 975 } 976 977 /* BIO_READ means the host writes into our buffer. */ 978 if (bp->bio_cmd == BIO_READ) 979 writable = sg->sg_nseg - 1; 980 } else if (bp->bio_cmd == BIO_DELETE) { 981 struct virtio_blk_discard_write_zeroes *discard; 982 983 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO); 984 if (discard == NULL) 985 return (ENOMEM); 986 987 bp->bio_driver1 = discard; 988 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE); 989 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE); 990 error = sglist_append(sg, discard, sizeof(*discard)); 991 if (error || sg->sg_nseg == sg->sg_maxseg) { 992 panic("%s: bio %p data buffer too big %d", 993 __func__, bp, error); 994 } 995 } 996 997 writable++; 998 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); 999 readable = sg->sg_nseg - writable; 1000 1001 error = virtqueue_enqueue(vq, req, sg, readable, writable); 1002 if (error == 0 && ordered) 1003 sc->vtblk_req_ordered = req; 1004 1005 return (error); 1006 } 1007 1008 static int 1009 vtblk_request_error(struct vtblk_request *req) 1010 { 1011 int error; 1012 1013 switch (req->vbr_ack) { 1014 case VIRTIO_BLK_S_OK: 1015 error = 0; 1016 break; 1017 case VIRTIO_BLK_S_UNSUPP: 1018 error = ENOTSUP; 1019 break; 1020 default: 1021 error = EIO; 1022 break; 1023 } 1024 1025 return (error); 1026 } 1027 1028 static void 1029 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1030 { 1031 struct vtblk_request *req; 1032 struct bio *bp; 1033 1034 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { 1035 if (sc->vtblk_req_ordered != NULL) { 1036 MPASS(sc->vtblk_req_ordered == req); 1037 sc->vtblk_req_ordered = NULL; 1038 } 1039 1040 bp = req->vbr_bp; 1041 bp->bio_error = vtblk_request_error(req); 1042 TAILQ_INSERT_TAIL(queue, bp, bio_queue); 1043 1044 vtblk_request_enqueue(sc, req); 1045 } 1046 } 1047 1048 static void 1049 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue) 1050 { 1051 struct bio *bp, *tmp; 1052 1053 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) { 1054 if (bp->bio_error != 0) 1055 disk_err(bp, "hard error", -1, 1); 1056 vtblk_bio_done(sc, bp, bp->bio_error); 1057 } 1058 } 1059 1060 static void 1061 vtblk_drain_vq(struct vtblk_softc *sc) 1062 { 1063 struct virtqueue *vq; 1064 struct vtblk_request *req; 1065 int last; 1066 1067 vq = sc->vtblk_vq; 1068 last = 0; 1069 1070 while ((req = virtqueue_drain(vq, &last)) != NULL) { 1071 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1072 vtblk_request_enqueue(sc, req); 1073 } 1074 1075 sc->vtblk_req_ordered = NULL; 1076 KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); 1077 } 1078 1079 static void 1080 vtblk_drain(struct vtblk_softc *sc) 1081 { 1082 struct bio_queue_head *bioq; 1083 struct vtblk_request *req; 1084 struct bio *bp; 1085 1086 bioq = &sc->vtblk_bioq; 1087 1088 if (sc->vtblk_vq != NULL) { 1089 struct bio_queue queue; 1090 1091 TAILQ_INIT(&queue); 1092 vtblk_queue_completed(sc, &queue); 1093 vtblk_done_completed(sc, &queue); 1094 1095 vtblk_drain_vq(sc); 1096 } 1097 1098 while ((req = vtblk_request_next_ready(sc)) != NULL) { 1099 vtblk_bio_done(sc, req->vbr_bp, ENXIO); 1100 vtblk_request_enqueue(sc, req); 1101 } 1102 1103 while (bioq_first(bioq) != NULL) { 1104 bp = bioq_takefirst(bioq); 1105 vtblk_bio_done(sc, bp, ENXIO); 1106 } 1107 1108 vtblk_request_free(sc); 1109 } 1110 1111 static void 1112 vtblk_startio(struct vtblk_softc *sc) 1113 { 1114 struct virtqueue *vq; 1115 struct vtblk_request *req; 1116 int enq; 1117 1118 VTBLK_LOCK_ASSERT(sc); 1119 vq = sc->vtblk_vq; 1120 enq = 0; 1121 1122 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1123 return; 1124 1125 while (!virtqueue_full(vq)) { 1126 req = vtblk_request_next(sc); 1127 if (req == NULL) 1128 break; 1129 1130 if (vtblk_request_execute(sc, req) != 0) { 1131 vtblk_request_requeue_ready(sc, req); 1132 break; 1133 } 1134 1135 enq++; 1136 } 1137 1138 if (enq > 0) 1139 virtqueue_notify(vq); 1140 } 1141 1142 static void 1143 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error) 1144 { 1145 1146 /* Because of GEOM direct dispatch, we cannot hold any locks. */ 1147 if (sc != NULL) 1148 VTBLK_LOCK_ASSERT_NOTOWNED(sc); 1149 1150 if (error) { 1151 bp->bio_resid = bp->bio_bcount; 1152 bp->bio_error = error; 1153 bp->bio_flags |= BIO_ERROR; 1154 } 1155 1156 if (bp->bio_driver1 != NULL) { 1157 free(bp->bio_driver1, M_DEVBUF); 1158 bp->bio_driver1 = NULL; 1159 } 1160 1161 biodone(bp); 1162 } 1163 1164 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ 1165 if (virtio_with_feature(_dev, _feature)) { \ 1166 virtio_read_device_config(_dev, \ 1167 offsetof(struct virtio_blk_config, _field), \ 1168 &(_cfg)->_field, sizeof((_cfg)->_field)); \ 1169 } 1170 1171 static void 1172 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) 1173 { 1174 device_t dev; 1175 1176 dev = sc->vtblk_dev; 1177 1178 bzero(blkcfg, sizeof(struct virtio_blk_config)); 1179 1180 /* The capacity is always available. */ 1181 virtio_read_device_config(dev, offsetof(struct virtio_blk_config, 1182 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); 1183 1184 /* Read the configuration if the feature was negotiated. */ 1185 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); 1186 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); 1187 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1188 geometry.cylinders, blkcfg); 1189 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1190 geometry.heads, blkcfg); 1191 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, 1192 geometry.sectors, blkcfg); 1193 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); 1194 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1195 topology.physical_block_exp, blkcfg); 1196 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1197 topology.alignment_offset, blkcfg); 1198 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1199 topology.min_io_size, blkcfg); 1200 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, 1201 topology.opt_io_size, blkcfg); 1202 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg); 1203 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors, 1204 blkcfg); 1205 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg); 1206 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment, 1207 blkcfg); 1208 } 1209 1210 #undef VTBLK_GET_CONFIG 1211 1212 static void 1213 vtblk_ident(struct vtblk_softc *sc) 1214 { 1215 struct bio buf; 1216 struct disk *dp; 1217 struct vtblk_request *req; 1218 int len, error; 1219 1220 dp = sc->vtblk_disk; 1221 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); 1222 1223 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) 1224 return; 1225 1226 req = vtblk_request_dequeue(sc); 1227 if (req == NULL) 1228 return; 1229 1230 req->vbr_ack = -1; 1231 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID); 1232 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1233 req->vbr_hdr.sector = 0; 1234 1235 req->vbr_bp = &buf; 1236 g_reset_bio(&buf); 1237 1238 buf.bio_cmd = BIO_READ; 1239 buf.bio_data = dp->d_ident; 1240 buf.bio_bcount = len; 1241 1242 VTBLK_LOCK(sc); 1243 error = vtblk_poll_request(sc, req); 1244 VTBLK_UNLOCK(sc); 1245 1246 vtblk_request_enqueue(sc, req); 1247 1248 if (error) { 1249 device_printf(sc->vtblk_dev, 1250 "error getting device identifier: %d\n", error); 1251 } 1252 } 1253 1254 static int 1255 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) 1256 { 1257 struct virtqueue *vq; 1258 int error; 1259 1260 vq = sc->vtblk_vq; 1261 1262 if (!virtqueue_empty(vq)) 1263 return (EBUSY); 1264 1265 error = vtblk_request_execute(sc, req); 1266 if (error) 1267 return (error); 1268 1269 virtqueue_notify(vq); 1270 virtqueue_poll(vq, NULL); 1271 1272 error = vtblk_request_error(req); 1273 if (error && bootverbose) { 1274 device_printf(sc->vtblk_dev, 1275 "%s: IO error: %d\n", __func__, error); 1276 } 1277 1278 return (error); 1279 } 1280 1281 static int 1282 vtblk_quiesce(struct vtblk_softc *sc) 1283 { 1284 int error; 1285 1286 VTBLK_LOCK_ASSERT(sc); 1287 error = 0; 1288 1289 while (!virtqueue_empty(sc->vtblk_vq)) { 1290 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", 1291 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { 1292 error = EBUSY; 1293 break; 1294 } 1295 } 1296 1297 return (error); 1298 } 1299 1300 static void 1301 vtblk_vq_intr(void *xsc) 1302 { 1303 struct vtblk_softc *sc; 1304 struct virtqueue *vq; 1305 struct bio_queue queue; 1306 1307 sc = xsc; 1308 vq = sc->vtblk_vq; 1309 TAILQ_INIT(&queue); 1310 1311 VTBLK_LOCK(sc); 1312 1313 again: 1314 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) 1315 goto out; 1316 1317 vtblk_queue_completed(sc, &queue); 1318 vtblk_startio(sc); 1319 1320 if (virtqueue_enable_intr(vq) != 0) { 1321 virtqueue_disable_intr(vq); 1322 goto again; 1323 } 1324 1325 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND) 1326 wakeup(&sc->vtblk_vq); 1327 1328 out: 1329 VTBLK_UNLOCK(sc); 1330 vtblk_done_completed(sc, &queue); 1331 } 1332 1333 static void 1334 vtblk_stop(struct vtblk_softc *sc) 1335 { 1336 1337 virtqueue_disable_intr(sc->vtblk_vq); 1338 virtio_stop(sc->vtblk_dev); 1339 } 1340 1341 static void 1342 vtblk_dump_quiesce(struct vtblk_softc *sc) 1343 { 1344 1345 /* 1346 * Spin here until all the requests in-flight at the time of the 1347 * dump are completed and queued. The queued requests will be 1348 * biodone'd once the dump is finished. 1349 */ 1350 while (!virtqueue_empty(sc->vtblk_vq)) 1351 vtblk_queue_completed(sc, &sc->vtblk_dump_queue); 1352 } 1353 1354 static int 1355 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset, 1356 size_t length) 1357 { 1358 struct bio buf; 1359 struct vtblk_request *req; 1360 1361 req = &sc->vtblk_dump_request; 1362 req->vbr_ack = -1; 1363 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT); 1364 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1365 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE); 1366 1367 req->vbr_bp = &buf; 1368 g_reset_bio(&buf); 1369 1370 buf.bio_cmd = BIO_WRITE; 1371 buf.bio_data = virtual; 1372 buf.bio_bcount = length; 1373 1374 return (vtblk_poll_request(sc, req)); 1375 } 1376 1377 static int 1378 vtblk_dump_flush(struct vtblk_softc *sc) 1379 { 1380 struct bio buf; 1381 struct vtblk_request *req; 1382 1383 req = &sc->vtblk_dump_request; 1384 req->vbr_ack = -1; 1385 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH); 1386 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1); 1387 req->vbr_hdr.sector = 0; 1388 1389 req->vbr_bp = &buf; 1390 g_reset_bio(&buf); 1391 1392 buf.bio_cmd = BIO_FLUSH; 1393 1394 return (vtblk_poll_request(sc, req)); 1395 } 1396 1397 static void 1398 vtblk_dump_complete(struct vtblk_softc *sc) 1399 { 1400 1401 vtblk_dump_flush(sc); 1402 1403 VTBLK_UNLOCK(sc); 1404 vtblk_done_completed(sc, &sc->vtblk_dump_queue); 1405 VTBLK_LOCK(sc); 1406 } 1407 1408 static void 1409 vtblk_set_write_cache(struct vtblk_softc *sc, int wc) 1410 { 1411 1412 /* Set either writeback (1) or writethrough (0) mode. */ 1413 virtio_write_dev_config_1(sc->vtblk_dev, 1414 offsetof(struct virtio_blk_config, wce), wc); 1415 } 1416 1417 static int 1418 vtblk_write_cache_enabled(struct vtblk_softc *sc, 1419 struct virtio_blk_config *blkcfg) 1420 { 1421 int wc; 1422 1423 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) { 1424 wc = vtblk_tunable_int(sc, "writecache_mode", 1425 vtblk_writecache_mode); 1426 if (wc >= 0 && wc < VTBLK_CACHE_MAX) 1427 vtblk_set_write_cache(sc, wc); 1428 else 1429 wc = blkcfg->wce; 1430 } else 1431 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH); 1432 1433 return (wc); 1434 } 1435 1436 static int 1437 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) 1438 { 1439 struct vtblk_softc *sc; 1440 int wc, error; 1441 1442 sc = oidp->oid_arg1; 1443 wc = sc->vtblk_write_cache; 1444 1445 error = sysctl_handle_int(oidp, &wc, 0, req); 1446 if (error || req->newptr == NULL) 1447 return (error); 1448 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0) 1449 return (EPERM); 1450 if (wc < 0 || wc >= VTBLK_CACHE_MAX) 1451 return (EINVAL); 1452 1453 VTBLK_LOCK(sc); 1454 sc->vtblk_write_cache = wc; 1455 vtblk_set_write_cache(sc, sc->vtblk_write_cache); 1456 VTBLK_UNLOCK(sc); 1457 1458 return (0); 1459 } 1460 1461 static void 1462 vtblk_setup_sysctl(struct vtblk_softc *sc) 1463 { 1464 device_t dev; 1465 struct sysctl_ctx_list *ctx; 1466 struct sysctl_oid *tree; 1467 struct sysctl_oid_list *child; 1468 1469 dev = sc->vtblk_dev; 1470 ctx = device_get_sysctl_ctx(dev); 1471 tree = device_get_sysctl_tree(dev); 1472 child = SYSCTL_CHILDREN(tree); 1473 1474 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", 1475 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0, 1476 vtblk_write_cache_sysctl, "I", 1477 "Write cache mode (writethrough (0) or writeback (1))"); 1478 } 1479 1480 static int 1481 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) 1482 { 1483 char path[64]; 1484 1485 snprintf(path, sizeof(path), 1486 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); 1487 TUNABLE_INT_FETCH(path, &def); 1488 1489 return (def); 1490 } 1491