/*- * Copyright (c) 2011, Bryan Venteicher * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* Driver for VirtIO block devices. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "virtio_if.h" struct vtblk_request { struct virtio_blk_outhdr vbr_hdr; struct bio *vbr_bp; uint8_t vbr_ack; TAILQ_ENTRY(vtblk_request) vbr_link; }; enum vtblk_cache_mode { VTBLK_CACHE_WRITETHROUGH, VTBLK_CACHE_WRITEBACK, VTBLK_CACHE_MAX }; struct vtblk_softc { device_t vtblk_dev; struct mtx vtblk_mtx; uint64_t vtblk_features; uint32_t vtblk_flags; #define VTBLK_FLAG_INDIRECT 0x0001 #define VTBLK_FLAG_READONLY 0x0002 #define VTBLK_FLAG_DETACH 0x0004 #define VTBLK_FLAG_SUSPEND 0x0008 #define VTBLK_FLAG_DUMPING 0x0010 #define VTBLK_FLAG_BARRIER 0x0020 #define VTBLK_FLAG_WC_CONFIG 0x0040 struct virtqueue *vtblk_vq; struct sglist *vtblk_sglist; struct disk *vtblk_disk; struct bio_queue_head vtblk_bioq; TAILQ_HEAD(, vtblk_request) vtblk_req_free; TAILQ_HEAD(, vtblk_request) vtblk_req_ready; struct vtblk_request *vtblk_req_ordered; int vtblk_max_nsegs; int vtblk_request_count; enum vtblk_cache_mode vtblk_write_cache; struct vtblk_request vtblk_dump_request; }; static struct virtio_feature_desc vtblk_feature_desc[] = { { VIRTIO_BLK_F_BARRIER, "HostBarrier" }, { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" }, { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" }, { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" }, { VIRTIO_BLK_F_RO, "ReadOnly" }, { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" }, { VIRTIO_BLK_F_SCSI, "SCSICmds" }, { VIRTIO_BLK_F_WCE, "WriteCache" }, { VIRTIO_BLK_F_TOPOLOGY, "Topology" }, { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" }, { 0, NULL } }; static int vtblk_modevent(module_t, int, void *); static int vtblk_probe(device_t); static int vtblk_attach(device_t); static int vtblk_detach(device_t); static int vtblk_suspend(device_t); static int vtblk_resume(device_t); static int vtblk_shutdown(device_t); static int vtblk_config_change(device_t); static int vtblk_open(struct disk *); static int vtblk_close(struct disk *); static int vtblk_ioctl(struct disk *, u_long, void *, int, struct thread *); static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t); static void vtblk_strategy(struct bio *); static void vtblk_negotiate_features(struct vtblk_softc *); static int vtblk_maximum_segments(struct vtblk_softc *, struct virtio_blk_config *); static int vtblk_alloc_virtqueue(struct vtblk_softc *); static void vtblk_resize_disk(struct vtblk_softc *, uint64_t); static void vtblk_set_write_cache(struct vtblk_softc *, int); static int vtblk_write_cache_enabled(struct vtblk_softc *sc, struct virtio_blk_config *); static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS); static void vtblk_alloc_disk(struct vtblk_softc *, struct virtio_blk_config *); static void vtblk_create_disk(struct vtblk_softc *); static int vtblk_quiesce(struct vtblk_softc *); static void vtblk_startio(struct vtblk_softc *); static struct vtblk_request * vtblk_bio_request(struct vtblk_softc *); static int vtblk_execute_request(struct vtblk_softc *, struct vtblk_request *); static void vtblk_vq_intr(void *); static void vtblk_stop(struct vtblk_softc *); static void vtblk_read_config(struct vtblk_softc *, struct virtio_blk_config *); static void vtblk_get_ident(struct vtblk_softc *); static void vtblk_prepare_dump(struct vtblk_softc *); static int vtblk_write_dump(struct vtblk_softc *, void *, off_t, size_t); static int vtblk_flush_dump(struct vtblk_softc *); static int vtblk_poll_request(struct vtblk_softc *, struct vtblk_request *); static void vtblk_finish_completed(struct vtblk_softc *); static void vtblk_drain_vq(struct vtblk_softc *, int); static void vtblk_drain(struct vtblk_softc *); static int vtblk_alloc_requests(struct vtblk_softc *); static void vtblk_free_requests(struct vtblk_softc *); static struct vtblk_request * vtblk_dequeue_request(struct vtblk_softc *); static void vtblk_enqueue_request(struct vtblk_softc *, struct vtblk_request *); static struct vtblk_request * vtblk_dequeue_ready(struct vtblk_softc *); static void vtblk_enqueue_ready(struct vtblk_softc *, struct vtblk_request *); static int vtblk_request_error(struct vtblk_request *); static void vtblk_finish_bio(struct bio *, int); static void vtblk_setup_sysctl(struct vtblk_softc *); static int vtblk_tunable_int(struct vtblk_softc *, const char *, int); /* Tunables. */ static int vtblk_no_ident = 0; TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident); static int vtblk_writecache_mode = -1; TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode); /* Features desired/implemented by this driver. */ #define VTBLK_FEATURES \ (VIRTIO_BLK_F_BARRIER | \ VIRTIO_BLK_F_SIZE_MAX | \ VIRTIO_BLK_F_SEG_MAX | \ VIRTIO_BLK_F_GEOMETRY | \ VIRTIO_BLK_F_RO | \ VIRTIO_BLK_F_BLK_SIZE | \ VIRTIO_BLK_F_WCE | \ VIRTIO_BLK_F_CONFIG_WCE | \ VIRTIO_RING_F_INDIRECT_DESC) #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx #define VTBLK_LOCK_INIT(_sc, _name) \ mtx_init(VTBLK_MTX((_sc)), (_name), \ "VirtIO Block Lock", MTX_DEF) #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc))) #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc))) #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc))) #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED) #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \ mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED) #define VTBLK_DISK_NAME "vtbd" #define VTBLK_QUIESCE_TIMEOUT (30 * hz) /* * Each block request uses at least two segments - one for the header * and one for the status. */ #define VTBLK_MIN_SEGMENTS 2 static device_method_t vtblk_methods[] = { /* Device methods. */ DEVMETHOD(device_probe, vtblk_probe), DEVMETHOD(device_attach, vtblk_attach), DEVMETHOD(device_detach, vtblk_detach), DEVMETHOD(device_suspend, vtblk_suspend), DEVMETHOD(device_resume, vtblk_resume), DEVMETHOD(device_shutdown, vtblk_shutdown), /* VirtIO methods. */ DEVMETHOD(virtio_config_change, vtblk_config_change), DEVMETHOD_END }; static driver_t vtblk_driver = { "vtblk", vtblk_methods, sizeof(struct vtblk_softc) }; static devclass_t vtblk_devclass; DRIVER_MODULE(virtio_blk, virtio_pci, vtblk_driver, vtblk_devclass, vtblk_modevent, 0); MODULE_VERSION(virtio_blk, 1); MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1); static int vtblk_modevent(module_t mod, int type, void *unused) { int error; error = 0; switch (type) { case MOD_LOAD: case MOD_QUIESCE: case MOD_UNLOAD: case MOD_SHUTDOWN: break; default: error = EOPNOTSUPP; break; } return (error); } static int vtblk_probe(device_t dev) { if (virtio_get_device_type(dev) != VIRTIO_ID_BLOCK) return (ENXIO); device_set_desc(dev, "VirtIO Block Adapter"); return (BUS_PROBE_DEFAULT); } static int vtblk_attach(device_t dev) { struct vtblk_softc *sc; struct virtio_blk_config blkcfg; int error; sc = device_get_softc(dev); sc->vtblk_dev = dev; VTBLK_LOCK_INIT(sc, device_get_nameunit(dev)); bioq_init(&sc->vtblk_bioq); TAILQ_INIT(&sc->vtblk_req_free); TAILQ_INIT(&sc->vtblk_req_ready); virtio_set_feature_desc(dev, vtblk_feature_desc); vtblk_negotiate_features(sc); if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) sc->vtblk_flags |= VTBLK_FLAG_INDIRECT; if (virtio_with_feature(dev, VIRTIO_BLK_F_RO)) sc->vtblk_flags |= VTBLK_FLAG_READONLY; if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER)) sc->vtblk_flags |= VTBLK_FLAG_BARRIER; if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE)) sc->vtblk_flags |= VTBLK_FLAG_WC_CONFIG; vtblk_setup_sysctl(sc); /* Get local copy of config. */ vtblk_read_config(sc, &blkcfg); /* * With the current sglist(9) implementation, it is not easy * for us to support a maximum segment size as adjacent * segments are coalesced. For now, just make sure it's larger * than the maximum supported transfer size. */ if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) { if (blkcfg.size_max < MAXPHYS) { error = ENOTSUP; device_printf(dev, "host requires unsupported " "maximum segment size feature\n"); goto fail; } } sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg); if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) { error = EINVAL; device_printf(dev, "fewer than minimum number of segments " "allowed: %d\n", sc->vtblk_max_nsegs); goto fail; } sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT); if (sc->vtblk_sglist == NULL) { error = ENOMEM; device_printf(dev, "cannot allocate sglist\n"); goto fail; } error = vtblk_alloc_virtqueue(sc); if (error) { device_printf(dev, "cannot allocate virtqueue\n"); goto fail; } error = vtblk_alloc_requests(sc); if (error) { device_printf(dev, "cannot preallocate requests\n"); goto fail; } vtblk_alloc_disk(sc, &blkcfg); error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY); if (error) { device_printf(dev, "cannot setup virtqueue interrupt\n"); goto fail; } vtblk_create_disk(sc); virtqueue_enable_intr(sc->vtblk_vq); fail: if (error) vtblk_detach(dev); return (error); } static int vtblk_detach(device_t dev) { struct vtblk_softc *sc; sc = device_get_softc(dev); VTBLK_LOCK(sc); sc->vtblk_flags |= VTBLK_FLAG_DETACH; if (device_is_attached(dev)) vtblk_stop(sc); VTBLK_UNLOCK(sc); vtblk_drain(sc); if (sc->vtblk_disk != NULL) { disk_destroy(sc->vtblk_disk); sc->vtblk_disk = NULL; } if (sc->vtblk_sglist != NULL) { sglist_free(sc->vtblk_sglist); sc->vtblk_sglist = NULL; } VTBLK_LOCK_DESTROY(sc); return (0); } static int vtblk_suspend(device_t dev) { struct vtblk_softc *sc; int error; sc = device_get_softc(dev); VTBLK_LOCK(sc); sc->vtblk_flags |= VTBLK_FLAG_SUSPEND; /* XXX BMV: virtio_stop(), etc needed here? */ error = vtblk_quiesce(sc); if (error) sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; VTBLK_UNLOCK(sc); return (error); } static int vtblk_resume(device_t dev) { struct vtblk_softc *sc; sc = device_get_softc(dev); VTBLK_LOCK(sc); /* XXX BMV: virtio_reinit(), etc needed here? */ sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND; vtblk_startio(sc); VTBLK_UNLOCK(sc); return (0); } static int vtblk_shutdown(device_t dev) { return (0); } static int vtblk_config_change(device_t dev) { struct vtblk_softc *sc; struct virtio_blk_config blkcfg; uint64_t capacity; sc = device_get_softc(dev); vtblk_read_config(sc, &blkcfg); /* Capacity is always in 512-byte units. */ capacity = blkcfg.capacity * 512; if (sc->vtblk_disk->d_mediasize != capacity) vtblk_resize_disk(sc, capacity); return (0); } static int vtblk_open(struct disk *dp) { struct vtblk_softc *sc; if ((sc = dp->d_drv1) == NULL) return (ENXIO); return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0); } static int vtblk_close(struct disk *dp) { struct vtblk_softc *sc; if ((sc = dp->d_drv1) == NULL) return (ENXIO); return (0); } static int vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag, struct thread *td) { struct vtblk_softc *sc; if ((sc = dp->d_drv1) == NULL) return (ENXIO); return (ENOTTY); } static int vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, size_t length) { struct disk *dp; struct vtblk_softc *sc; int error; dp = arg; if ((sc = dp->d_drv1) == NULL) return (ENXIO); VTBLK_LOCK(sc); if ((sc->vtblk_flags & VTBLK_FLAG_DUMPING) == 0) { vtblk_prepare_dump(sc); sc->vtblk_flags |= VTBLK_FLAG_DUMPING; } if (length > 0) error = vtblk_write_dump(sc, virtual, offset, length); else if (virtual == NULL && offset == 0) error = vtblk_flush_dump(sc); else { error = EINVAL; sc->vtblk_flags &= ~VTBLK_FLAG_DUMPING; } VTBLK_UNLOCK(sc); return (error); } static void vtblk_strategy(struct bio *bp) { struct vtblk_softc *sc; if ((sc = bp->bio_disk->d_drv1) == NULL) { vtblk_finish_bio(bp, EINVAL); return; } /* * Fail any write if RO. Unfortunately, there does not seem to * be a better way to report our readonly'ness to GEOM above. */ if (sc->vtblk_flags & VTBLK_FLAG_READONLY && (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_FLUSH)) { vtblk_finish_bio(bp, EROFS); return; } #ifdef INVARIANTS /* * Prevent read/write buffers spanning too many segments from * getting into the queue. This should only trip if d_maxsize * was incorrectly set. */ if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { int nsegs, max_nsegs; nsegs = sglist_count(bp->bio_data, bp->bio_bcount); max_nsegs = sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS; KASSERT(nsegs <= max_nsegs, ("%s: bio %p spanned too many segments: %d, max: %d", __func__, bp, nsegs, max_nsegs)); } #endif VTBLK_LOCK(sc); if (sc->vtblk_flags & VTBLK_FLAG_DETACH) vtblk_finish_bio(bp, ENXIO); else { bioq_disksort(&sc->vtblk_bioq, bp); if ((sc->vtblk_flags & VTBLK_FLAG_SUSPEND) == 0) vtblk_startio(sc); } VTBLK_UNLOCK(sc); } static void vtblk_negotiate_features(struct vtblk_softc *sc) { device_t dev; uint64_t features; dev = sc->vtblk_dev; features = VTBLK_FEATURES; sc->vtblk_features = virtio_negotiate_features(dev, features); } static int vtblk_maximum_segments(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) { device_t dev; int nsegs; dev = sc->vtblk_dev; nsegs = VTBLK_MIN_SEGMENTS; if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) { nsegs += MIN(blkcfg->seg_max, MAXPHYS / PAGE_SIZE + 1); if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT) nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT); } else nsegs += 1; return (nsegs); } static int vtblk_alloc_virtqueue(struct vtblk_softc *sc) { device_t dev; struct vq_alloc_info vq_info; dev = sc->vtblk_dev; VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs, vtblk_vq_intr, sc, &sc->vtblk_vq, "%s request", device_get_nameunit(dev)); return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info)); } static void vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity) { device_t dev; struct disk *dp; int error; dev = sc->vtblk_dev; dp = sc->vtblk_disk; dp->d_mediasize = new_capacity; if (bootverbose) { device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n", (uintmax_t) dp->d_mediasize >> 20, (uintmax_t) dp->d_mediasize / dp->d_sectorsize, dp->d_sectorsize); } error = disk_resize(dp, M_NOWAIT); if (error) { device_printf(dev, "disk_resize(9) failed, error: %d\n", error); } } static void vtblk_set_write_cache(struct vtblk_softc *sc, int wc) { /* Set either writeback (1) or writethrough (0) mode. */ virtio_write_dev_config_1(sc->vtblk_dev, offsetof(struct virtio_blk_config, writeback), wc); } static int vtblk_write_cache_enabled(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) { int wc; if (sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) { wc = vtblk_tunable_int(sc, "writecache_mode", vtblk_writecache_mode); if (wc >= 0 && wc < VTBLK_CACHE_MAX) vtblk_set_write_cache(sc, wc); else wc = blkcfg->writeback; } else wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_WCE); return (wc); } static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS) { struct vtblk_softc *sc; int wc, error; sc = oidp->oid_arg1; wc = sc->vtblk_write_cache; error = sysctl_handle_int(oidp, &wc, 0, req); if (error || req->newptr == NULL) return (error); if ((sc->vtblk_flags & VTBLK_FLAG_WC_CONFIG) == 0) return (EPERM); if (wc < 0 || wc >= VTBLK_CACHE_MAX) return (EINVAL); VTBLK_LOCK(sc); sc->vtblk_write_cache = wc; vtblk_set_write_cache(sc, sc->vtblk_write_cache); VTBLK_UNLOCK(sc); return (0); } static void vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) { device_t dev; struct disk *dp; dev = sc->vtblk_dev; sc->vtblk_disk = dp = disk_alloc(); dp->d_open = vtblk_open; dp->d_close = vtblk_close; dp->d_ioctl = vtblk_ioctl; dp->d_strategy = vtblk_strategy; dp->d_name = VTBLK_DISK_NAME; dp->d_unit = device_get_unit(dev); dp->d_drv1 = sc; dp->d_flags = DISKFLAG_CANFLUSHCACHE; dp->d_hba_vendor = virtio_get_vendor(dev); dp->d_hba_device = virtio_get_device(dev); dp->d_hba_subvendor = virtio_get_subvendor(dev); dp->d_hba_subdevice = virtio_get_subdevice(dev); if ((sc->vtblk_flags & VTBLK_FLAG_READONLY) == 0) dp->d_dump = vtblk_dump; /* Capacity is always in 512-byte units. */ dp->d_mediasize = blkcfg->capacity * 512; if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE)) dp->d_sectorsize = blkcfg->blk_size; else dp->d_sectorsize = 512; /* * The VirtIO maximum I/O size is given in terms of segments. * However, FreeBSD limits I/O size by logical buffer size, not * by physically contiguous pages. Therefore, we have to assume * no pages are contiguous. This may impose an artificially low * maximum I/O size. But in practice, since QEMU advertises 128 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE, * which is typically greater than MAXPHYS. Eventually we should * just advertise MAXPHYS and split buffers that are too big. * * Note we must subtract one additional segment in case of non * page aligned buffers. */ dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) * PAGE_SIZE; if (dp->d_maxsize < PAGE_SIZE) dp->d_maxsize = PAGE_SIZE; /* XXX */ if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) { dp->d_fwsectors = blkcfg->geometry.sectors; dp->d_fwheads = blkcfg->geometry.heads; } if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY)) { dp->d_stripesize = dp->d_sectorsize * (1 << blkcfg->topology.physical_block_exp); dp->d_stripeoffset = (dp->d_stripesize - blkcfg->topology.alignment_offset * dp->d_sectorsize) % dp->d_stripesize; } if (vtblk_write_cache_enabled(sc, blkcfg) != 0) sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK; else sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH; } static void vtblk_create_disk(struct vtblk_softc *sc) { struct disk *dp; dp = sc->vtblk_disk; /* * Retrieving the identification string must be done after * the virtqueue interrupt is setup otherwise it will hang. */ vtblk_get_ident(sc); device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n", (uintmax_t) dp->d_mediasize >> 20, (uintmax_t) dp->d_mediasize / dp->d_sectorsize, dp->d_sectorsize); disk_create(dp, DISK_VERSION); } static int vtblk_quiesce(struct vtblk_softc *sc) { int error; error = 0; VTBLK_LOCK_ASSERT(sc); while (!virtqueue_empty(sc->vtblk_vq)) { if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq", VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) { error = EBUSY; break; } } return (error); } static void vtblk_startio(struct vtblk_softc *sc) { struct virtqueue *vq; struct vtblk_request *req; int enq; vq = sc->vtblk_vq; enq = 0; VTBLK_LOCK_ASSERT(sc); while (!virtqueue_full(vq)) { if ((req = vtblk_dequeue_ready(sc)) == NULL) req = vtblk_bio_request(sc); if (req == NULL) break; if (vtblk_execute_request(sc, req) != 0) { vtblk_enqueue_ready(sc, req); break; } enq++; } if (enq > 0) virtqueue_notify(vq); } static struct vtblk_request * vtblk_bio_request(struct vtblk_softc *sc) { struct bio_queue_head *bioq; struct vtblk_request *req; struct bio *bp; bioq = &sc->vtblk_bioq; if (bioq_first(bioq) == NULL) return (NULL); req = vtblk_dequeue_request(sc); if (req == NULL) return (NULL); bp = bioq_takefirst(bioq); req->vbr_bp = bp; req->vbr_ack = -1; req->vbr_hdr.ioprio = 1; switch (bp->bio_cmd) { case BIO_FLUSH: req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; break; case BIO_READ: req->vbr_hdr.type = VIRTIO_BLK_T_IN; req->vbr_hdr.sector = bp->bio_offset / 512; break; case BIO_WRITE: req->vbr_hdr.type = VIRTIO_BLK_T_OUT; req->vbr_hdr.sector = bp->bio_offset / 512; break; default: panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd); } return (req); } static int vtblk_execute_request(struct vtblk_softc *sc, struct vtblk_request *req) { struct virtqueue *vq; struct sglist *sg; struct bio *bp; int ordered, readable, writable, error; vq = sc->vtblk_vq; sg = sc->vtblk_sglist; bp = req->vbr_bp; ordered = 0; writable = 0; VTBLK_LOCK_ASSERT(sc); /* * Wait until the ordered request completes before * executing subsequent requests. */ if (sc->vtblk_req_ordered != NULL) return (EBUSY); if (bp->bio_flags & BIO_ORDERED) { if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) { /* * This request will be executed once all * the in-flight requests are completed. */ if (!virtqueue_empty(vq)) return (EBUSY); ordered = 1; } else req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER; } sglist_reset(sg); sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr)); if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { error = sglist_append(sg, bp->bio_data, bp->bio_bcount); if (error || sg->sg_nseg == sg->sg_maxseg) panic("%s: data buffer too big bio:%p error:%d", __func__, bp, error); /* BIO_READ means the host writes into our buffer. */ if (bp->bio_cmd == BIO_READ) writable = sg->sg_nseg - 1; } writable++; sglist_append(sg, &req->vbr_ack, sizeof(uint8_t)); readable = sg->sg_nseg - writable; error = virtqueue_enqueue(vq, req, sg, readable, writable); if (error == 0 && ordered) sc->vtblk_req_ordered = req; return (error); } static void vtblk_vq_intr(void *xsc) { struct vtblk_softc *sc; struct virtqueue *vq; sc = xsc; vq = sc->vtblk_vq; again: VTBLK_LOCK(sc); if (sc->vtblk_flags & VTBLK_FLAG_DETACH) { VTBLK_UNLOCK(sc); return; } vtblk_finish_completed(sc); if ((sc->vtblk_flags & VTBLK_FLAG_SUSPEND) == 0) vtblk_startio(sc); else wakeup(&sc->vtblk_vq); if (virtqueue_enable_intr(vq) != 0) { virtqueue_disable_intr(vq); VTBLK_UNLOCK(sc); goto again; } VTBLK_UNLOCK(sc); } static void vtblk_stop(struct vtblk_softc *sc) { virtqueue_disable_intr(sc->vtblk_vq); virtio_stop(sc->vtblk_dev); } #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \ if (virtio_with_feature(_dev, _feature)) { \ virtio_read_device_config(_dev, \ offsetof(struct virtio_blk_config, _field), \ &(_cfg)->_field, sizeof((_cfg)->_field)); \ } static void vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg) { device_t dev; dev = sc->vtblk_dev; bzero(blkcfg, sizeof(struct virtio_blk_config)); /* The capacity is always available. */ virtio_read_device_config(dev, offsetof(struct virtio_blk_config, capacity), &blkcfg->capacity, sizeof(blkcfg->capacity)); /* Read the configuration if the feature was negotiated. */ VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg); VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg); VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY, geometry, blkcfg); VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg); VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY, topology, blkcfg); VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, writeback, blkcfg); } #undef VTBLK_GET_CONFIG static void vtblk_get_ident(struct vtblk_softc *sc) { struct bio buf; struct disk *dp; struct vtblk_request *req; int len, error; dp = sc->vtblk_disk; len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE); if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0) return; req = vtblk_dequeue_request(sc); if (req == NULL) return; req->vbr_ack = -1; req->vbr_hdr.type = VIRTIO_BLK_T_GET_ID; req->vbr_hdr.ioprio = 1; req->vbr_hdr.sector = 0; req->vbr_bp = &buf; bzero(&buf, sizeof(struct bio)); buf.bio_cmd = BIO_READ; buf.bio_data = dp->d_ident; buf.bio_bcount = len; VTBLK_LOCK(sc); error = vtblk_poll_request(sc, req); VTBLK_UNLOCK(sc); vtblk_enqueue_request(sc, req); if (error) { device_printf(sc->vtblk_dev, "error getting device identifier: %d\n", error); } } static void vtblk_prepare_dump(struct vtblk_softc *sc) { device_t dev; struct virtqueue *vq; dev = sc->vtblk_dev; vq = sc->vtblk_vq; vtblk_stop(sc); /* * Drain all requests caught in-flight in the virtqueue, * skipping biodone(). When dumping, only one request is * outstanding at a time, and we just poll the virtqueue * for the response. */ vtblk_drain_vq(sc, 1); if (virtio_reinit(dev, sc->vtblk_features) != 0) { panic("%s: cannot reinit VirtIO block device during dump", device_get_nameunit(dev)); } virtqueue_disable_intr(vq); virtio_reinit_complete(dev); } static int vtblk_write_dump(struct vtblk_softc *sc, void *virtual, off_t offset, size_t length) { struct bio buf; struct vtblk_request *req; req = &sc->vtblk_dump_request; req->vbr_ack = -1; req->vbr_hdr.type = VIRTIO_BLK_T_OUT; req->vbr_hdr.ioprio = 1; req->vbr_hdr.sector = offset / 512; req->vbr_bp = &buf; bzero(&buf, sizeof(struct bio)); buf.bio_cmd = BIO_WRITE; buf.bio_data = virtual; buf.bio_bcount = length; return (vtblk_poll_request(sc, req)); } static int vtblk_flush_dump(struct vtblk_softc *sc) { struct bio buf; struct vtblk_request *req; req = &sc->vtblk_dump_request; req->vbr_ack = -1; req->vbr_hdr.type = VIRTIO_BLK_T_FLUSH; req->vbr_hdr.ioprio = 1; req->vbr_hdr.sector = 0; req->vbr_bp = &buf; bzero(&buf, sizeof(struct bio)); buf.bio_cmd = BIO_FLUSH; return (vtblk_poll_request(sc, req)); } static int vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req) { struct virtqueue *vq; int error; vq = sc->vtblk_vq; if (!virtqueue_empty(vq)) return (EBUSY); error = vtblk_execute_request(sc, req); if (error) return (error); virtqueue_notify(vq); virtqueue_poll(vq, NULL); error = vtblk_request_error(req); if (error && bootverbose) { device_printf(sc->vtblk_dev, "%s: IO error: %d\n", __func__, error); } return (error); } static void vtblk_finish_completed(struct vtblk_softc *sc) { struct vtblk_request *req; struct bio *bp; int error; while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) { bp = req->vbr_bp; if (sc->vtblk_req_ordered != NULL) { /* This should be the only outstanding request. */ MPASS(sc->vtblk_req_ordered == req); sc->vtblk_req_ordered = NULL; } error = vtblk_request_error(req); if (error) disk_err(bp, "hard error", -1, 1); vtblk_finish_bio(bp, error); vtblk_enqueue_request(sc, req); } } static void vtblk_drain_vq(struct vtblk_softc *sc, int skip_done) { struct virtqueue *vq; struct vtblk_request *req; int last; vq = sc->vtblk_vq; last = 0; while ((req = virtqueue_drain(vq, &last)) != NULL) { if (!skip_done) vtblk_finish_bio(req->vbr_bp, ENXIO); vtblk_enqueue_request(sc, req); } sc->vtblk_req_ordered = NULL; KASSERT(virtqueue_empty(vq), ("virtqueue not empty")); } static void vtblk_drain(struct vtblk_softc *sc) { struct bio_queue_head *bioq; struct vtblk_request *req; struct bio *bp; bioq = &sc->vtblk_bioq; if (sc->vtblk_vq != NULL) { vtblk_finish_completed(sc); vtblk_drain_vq(sc, 0); } while ((req = vtblk_dequeue_ready(sc)) != NULL) { vtblk_finish_bio(req->vbr_bp, ENXIO); vtblk_enqueue_request(sc, req); } while (bioq_first(bioq) != NULL) { bp = bioq_takefirst(bioq); vtblk_finish_bio(bp, ENXIO); } vtblk_free_requests(sc); } #ifdef INVARIANTS static void vtblk_request_invariants(struct vtblk_request *req) { int hdr_nsegs, ack_nsegs; hdr_nsegs = sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)); ack_nsegs = sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)); KASSERT(hdr_nsegs == 1, ("request header crossed page boundary")); KASSERT(ack_nsegs == 1, ("request ack crossed page boundary")); } #endif static int vtblk_alloc_requests(struct vtblk_softc *sc) { struct vtblk_request *req; int i, nreqs; nreqs = virtqueue_size(sc->vtblk_vq); /* * Preallocate sufficient requests to keep the virtqueue full. Each * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce * the number allocated when indirect descriptors are not available. */ if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0) nreqs /= VTBLK_MIN_SEGMENTS; for (i = 0; i < nreqs; i++) { req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT); if (req == NULL) return (ENOMEM); #ifdef INVARIANTS vtblk_request_invariants(req); #endif sc->vtblk_request_count++; vtblk_enqueue_request(sc, req); } return (0); } static void vtblk_free_requests(struct vtblk_softc *sc) { struct vtblk_request *req; KASSERT(TAILQ_EMPTY(&sc->vtblk_req_ready), ("%s: ready requests left on queue", __func__)); while ((req = vtblk_dequeue_request(sc)) != NULL) { sc->vtblk_request_count--; free(req, M_DEVBUF); } KASSERT(sc->vtblk_request_count == 0, ("%s: leaked %d requests", __func__, sc->vtblk_request_count)); } static struct vtblk_request * vtblk_dequeue_request(struct vtblk_softc *sc) { struct vtblk_request *req; req = TAILQ_FIRST(&sc->vtblk_req_free); if (req != NULL) TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link); return (req); } static void vtblk_enqueue_request(struct vtblk_softc *sc, struct vtblk_request *req) { bzero(req, sizeof(struct vtblk_request)); TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link); } static struct vtblk_request * vtblk_dequeue_ready(struct vtblk_softc *sc) { struct vtblk_request *req; req = TAILQ_FIRST(&sc->vtblk_req_ready); if (req != NULL) TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link); return (req); } static void vtblk_enqueue_ready(struct vtblk_softc *sc, struct vtblk_request *req) { TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link); } static int vtblk_request_error(struct vtblk_request *req) { int error; switch (req->vbr_ack) { case VIRTIO_BLK_S_OK: error = 0; break; case VIRTIO_BLK_S_UNSUPP: error = ENOTSUP; break; default: error = EIO; break; } return (error); } static void vtblk_finish_bio(struct bio *bp, int error) { if (error) { bp->bio_resid = bp->bio_bcount; bp->bio_error = error; bp->bio_flags |= BIO_ERROR; } biodone(bp); } static void vtblk_setup_sysctl(struct vtblk_softc *sc) { device_t dev; struct sysctl_ctx_list *ctx; struct sysctl_oid *tree; struct sysctl_oid_list *child; dev = sc->vtblk_dev; ctx = device_get_sysctl_ctx(dev); tree = device_get_sysctl_tree(dev); child = SYSCTL_CHILDREN(tree); SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode", CTLTYPE_INT | CTLFLAG_RW, sc, 0, vtblk_write_cache_sysctl, "I", "Write cache mode (writethrough (0) or writeback (1))"); } static int vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def) { char path[64]; snprintf(path, sizeof(path), "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob); TUNABLE_INT_FETCH(path, &def); return (def); }