/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2011 NetApp, Inc. * All rights reserved. * Copyright 2020-2021 Joyent, Inc. * * 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, 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 NETAPP, INC ``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 NETAPP, INC OR CONTRIBUTORS 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. * * $FreeBSD$ */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "bhyverun.h" #include "config.h" #include "debug.h" #include "pci_emul.h" #include "virtio.h" #include "block_if.h" #define VTBLK_BSIZE 512 #define VTBLK_RINGSZ 128 _Static_assert(VTBLK_RINGSZ <= BLOCKIF_RING_MAX, "Each ring entry must be able to queue a request"); #define VTBLK_S_OK 0 #define VTBLK_S_IOERR 1 #define VTBLK_S_UNSUPP 2 #define VTBLK_BLK_ID_BYTES 20 + 1 /* Capability bits */ #define VTBLK_F_BARRIER (1 << 0) /* Does host support barriers? */ #define VTBLK_F_SIZE_MAX (1 << 1) /* Indicates maximum segment size */ #define VTBLK_F_SEG_MAX (1 << 2) /* Indicates maximum # of segments */ #define VTBLK_F_GEOMETRY (1 << 4) /* Legacy geometry available */ #define VTBLK_F_RO (1 << 5) /* Disk is read-only */ #define VTBLK_F_BLK_SIZE (1 << 6) /* Block size of disk is available*/ #define VTBLK_F_SCSI (1 << 7) /* Supports scsi command passthru */ #define VTBLK_F_FLUSH (1 << 9) /* Writeback mode enabled after reset */ #define VTBLK_F_WCE (1 << 9) /* Legacy alias for FLUSH */ #define VTBLK_F_TOPOLOGY (1 << 10) /* Topology information is available */ #define VTBLK_F_CONFIG_WCE (1 << 11) /* Writeback mode available in config */ #define VTBLK_F_MQ (1 << 12) /* Multi-Queue */ #define VTBLK_F_DISCARD (1 << 13) /* Trim blocks */ #define VTBLK_F_WRITE_ZEROES (1 << 14) /* Write zeros */ /* * Host capabilities */ #define VTBLK_S_HOSTCAPS \ ( VTBLK_F_SEG_MAX | \ VTBLK_F_BLK_SIZE | \ VTBLK_F_FLUSH | \ VTBLK_F_TOPOLOGY | \ VIRTIO_RING_F_INDIRECT_DESC ) /* indirect descriptors */ /* * The current blockif_delete() interface only allows a single delete * request at a time. */ #define VTBLK_MAX_DISCARD_SEG 1 /* * An arbitrary limit to prevent excessive latency due to large * delete requests. */ #define VTBLK_MAX_DISCARD_SECT ((16 << 20) / VTBLK_BSIZE) /* 16 MiB */ /* * Config space "registers" */ struct vtblk_config { uint64_t vbc_capacity; uint32_t vbc_size_max; uint32_t vbc_seg_max; struct { uint16_t cylinders; uint8_t heads; uint8_t sectors; } vbc_geometry; uint32_t vbc_blk_size; struct { uint8_t physical_block_exp; uint8_t alignment_offset; uint16_t min_io_size; uint32_t opt_io_size; } vbc_topology; uint8_t vbc_writeback; uint8_t unused0[1]; uint16_t num_queues; uint32_t max_discard_sectors; uint32_t max_discard_seg; uint32_t discard_sector_alignment; uint32_t max_write_zeroes_sectors; uint32_t max_write_zeroes_seg; uint8_t write_zeroes_may_unmap; uint8_t unused1[3]; } __packed; /* * Fixed-size block header */ struct virtio_blk_hdr { #define VBH_OP_READ 0 #define VBH_OP_WRITE 1 #define VBH_OP_SCSI_CMD 2 #define VBH_OP_SCSI_CMD_OUT 3 #define VBH_OP_FLUSH 4 #define VBH_OP_FLUSH_OUT 5 #define VBH_OP_IDENT 8 #define VBH_OP_DISCARD 11 #define VBH_OP_WRITE_ZEROES 13 #define VBH_FLAG_BARRIER 0x80000000 /* OR'ed into vbh_type */ uint32_t vbh_type; uint32_t vbh_ioprio; uint64_t vbh_sector; } __packed; /* * Debug printf */ static int pci_vtblk_debug; #define DPRINTF(params) if (pci_vtblk_debug) PRINTLN params #define WPRINTF(params) PRINTLN params struct pci_vtblk_ioreq { struct blockif_req io_req; struct pci_vtblk_softc *io_sc; uint8_t *io_status; uint16_t io_idx; }; struct virtio_blk_discard_write_zeroes { uint64_t sector; uint32_t num_sectors; struct { uint32_t unmap:1; uint32_t reserved:31; } flags; }; /* * Per-device softc */ struct pci_vtblk_softc { struct virtio_softc vbsc_vs; pthread_mutex_t vsc_mtx; struct vqueue_info vbsc_vq; struct vtblk_config vbsc_cfg; struct virtio_consts vbsc_consts; struct blockif_ctxt *bc; char vbsc_ident[VTBLK_BLK_ID_BYTES]; struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ]; }; static void pci_vtblk_reset(void *); static void pci_vtblk_notify(void *, struct vqueue_info *); static int pci_vtblk_cfgread(void *, int, int, uint32_t *); static int pci_vtblk_cfgwrite(void *, int, int, uint32_t); #ifdef BHYVE_SNAPSHOT static void pci_vtblk_pause(void *); static void pci_vtblk_resume(void *); static int pci_vtblk_snapshot(void *, struct vm_snapshot_meta *); #endif static struct virtio_consts vtblk_vi_consts = { .vc_name = "vtblk", .vc_nvq = 1, .vc_cfgsize = sizeof(struct vtblk_config), .vc_reset = pci_vtblk_reset, .vc_qnotify = pci_vtblk_notify, .vc_cfgread = pci_vtblk_cfgread, .vc_cfgwrite = pci_vtblk_cfgwrite, .vc_apply_features = NULL, .vc_hv_caps = VTBLK_S_HOSTCAPS, #ifdef BHYVE_SNAPSHOT .vc_pause = pci_vtblk_pause, .vc_resume = pci_vtblk_resume, .vc_snapshot = pci_vtblk_snapshot, #endif }; static void pci_vtblk_reset(void *vsc) { struct pci_vtblk_softc *sc = vsc; DPRINTF(("vtblk: device reset requested !")); vi_reset_dev(&sc->vbsc_vs); } static void pci_vtblk_done_locked(struct pci_vtblk_ioreq *io, int err) { struct pci_vtblk_softc *sc = io->io_sc; /* convert errno into a virtio block error return */ if (err == EOPNOTSUPP || err == ENOSYS) *io->io_status = VTBLK_S_UNSUPP; else if (err != 0) *io->io_status = VTBLK_S_IOERR; else *io->io_status = VTBLK_S_OK; /* * Return the descriptor back to the host. * We wrote 1 byte (our status) to host. */ vq_relchain(&sc->vbsc_vq, io->io_idx, 1); vq_endchains(&sc->vbsc_vq, 0); } #ifdef BHYVE_SNAPSHOT static void pci_vtblk_pause(void *vsc) { struct pci_vtblk_softc *sc = vsc; DPRINTF(("vtblk: device pause requested !\n")); blockif_pause(sc->bc); } static void pci_vtblk_resume(void *vsc) { struct pci_vtblk_softc *sc = vsc; DPRINTF(("vtblk: device resume requested !\n")); blockif_resume(sc->bc); } static int pci_vtblk_snapshot(void *vsc, struct vm_snapshot_meta *meta) { int ret; struct pci_vtblk_softc *sc = vsc; SNAPSHOT_VAR_OR_LEAVE(sc->vbsc_cfg, meta, ret, done); SNAPSHOT_BUF_OR_LEAVE(sc->vbsc_ident, sizeof(sc->vbsc_ident), meta, ret, done); done: return (ret); } #endif static void pci_vtblk_done(struct blockif_req *br, int err) { struct pci_vtblk_ioreq *io = br->br_param; struct pci_vtblk_softc *sc = io->io_sc; pthread_mutex_lock(&sc->vsc_mtx); pci_vtblk_done_locked(io, err); pthread_mutex_unlock(&sc->vsc_mtx); } static void pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq) { struct virtio_blk_hdr *vbh; struct pci_vtblk_ioreq *io; int i, n; int err; ssize_t iolen; int writeop, type; struct vi_req req; struct iovec iov[BLOCKIF_IOV_MAX + 2]; struct virtio_blk_discard_write_zeroes *discard; n = vq_getchain(vq, iov, BLOCKIF_IOV_MAX + 2, &req); /* * The first descriptor will be the read-only fixed header, * and the last is for status (hence +2 above and below). * The remaining iov's are the actual data I/O vectors. * * XXX - note - this fails on crash dump, which does a * VIRTIO_BLK_T_FLUSH with a zero transfer length */ assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2); io = &sc->vbsc_ios[req.idx]; assert(req.readable != 0); assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr)); vbh = (struct virtio_blk_hdr *)iov[0].iov_base; memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2)); io->io_req.br_iovcnt = n - 2; io->io_req.br_offset = vbh->vbh_sector * VTBLK_BSIZE; io->io_status = (uint8_t *)iov[--n].iov_base; assert(req.writable != 0); assert(iov[n].iov_len == 1); /* * XXX * The guest should not be setting the BARRIER flag because * we don't advertise the capability. */ type = vbh->vbh_type & ~VBH_FLAG_BARRIER; writeop = (type == VBH_OP_WRITE || type == VBH_OP_DISCARD); /* * - Write op implies read-only descriptor * - Read/ident op implies write-only descriptor * * By taking away either the read-only fixed header or the write-only * status iovec, the following condition should hold true. */ assert(n == (writeop ? req.readable : req.writable)); iolen = 0; for (i = 1; i < n; i++) { iolen += iov[i].iov_len; } io->io_req.br_resid = iolen; DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld", writeop ? "write/discard" : "read/ident", iolen, i - 1, io->io_req.br_offset)); switch (type) { case VBH_OP_READ: err = blockif_read(sc->bc, &io->io_req); break; case VBH_OP_WRITE: err = blockif_write(sc->bc, &io->io_req); break; case VBH_OP_DISCARD: /* * We currently only support a single request, if the guest * has submitted a request that doesn't conform to the * requirements, we return a error. */ if (iov[1].iov_len != sizeof (*discard)) { pci_vtblk_done_locked(io, EINVAL); return; } /* The segments to discard are provided rather than data */ discard = (struct virtio_blk_discard_write_zeroes *) iov[1].iov_base; /* * virtio v1.1 5.2.6.2: * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP * for discard and write zeroes commands if any unknown flag is * set. Furthermore, the device MUST set the status byte to * VIRTIO_BLK_S_UNSUPP for discard commands if the unmap flag * is set. * * Currently there are no known flags for a DISCARD request. */ if (discard->flags.unmap != 0 || discard->flags.reserved != 0) { pci_vtblk_done_locked(io, ENOTSUP); return; } /* Make sure the request doesn't exceed our size limit */ if (discard->num_sectors > VTBLK_MAX_DISCARD_SECT) { pci_vtblk_done_locked(io, EINVAL); return; } io->io_req.br_offset = discard->sector * VTBLK_BSIZE; io->io_req.br_resid = discard->num_sectors * VTBLK_BSIZE; err = blockif_delete(sc->bc, &io->io_req); break; case VBH_OP_FLUSH: case VBH_OP_FLUSH_OUT: err = blockif_flush(sc->bc, &io->io_req); break; case VBH_OP_IDENT: /* Assume a single buffer */ /* S/n equal to buffer is not zero-terminated. */ memset(iov[1].iov_base, 0, iov[1].iov_len); strncpy(iov[1].iov_base, sc->vbsc_ident, MIN(iov[1].iov_len, sizeof(sc->vbsc_ident))); pci_vtblk_done_locked(io, 0); return; default: pci_vtblk_done_locked(io, EOPNOTSUPP); return; } assert(err == 0); } static void pci_vtblk_notify(void *vsc, struct vqueue_info *vq) { struct pci_vtblk_softc *sc = vsc; while (vq_has_descs(vq)) pci_vtblk_proc(sc, vq); } static void pci_vtblk_resized(struct blockif_ctxt *bctxt __unused, void *arg, size_t new_size) { struct pci_vtblk_softc *sc; sc = arg; sc->vbsc_cfg.vbc_capacity = new_size / VTBLK_BSIZE; /* 512-byte units */ vi_interrupt(&sc->vbsc_vs, VIRTIO_PCI_ISR_CONFIG, sc->vbsc_vs.vs_msix_cfg_idx); } static int pci_vtblk_init(struct vmctx *ctx __unused, struct pci_devinst *pi, nvlist_t *nvl) { char bident[sizeof("XXX:XXX")]; struct blockif_ctxt *bctxt; const char *path, *serial; MD5_CTX mdctx; u_char digest[16]; struct pci_vtblk_softc *sc; off_t size; int i, sectsz, sts, sto; /* * The supplied backing file has to exist */ snprintf(bident, sizeof(bident), "%u:%u", pi->pi_slot, pi->pi_func); bctxt = blockif_open(nvl, bident); if (bctxt == NULL) { perror("Could not open backing file"); return (1); } size = blockif_size(bctxt); sectsz = blockif_sectsz(bctxt); blockif_psectsz(bctxt, &sts, &sto); sc = calloc(1, sizeof(struct pci_vtblk_softc)); sc->bc = bctxt; for (i = 0; i < VTBLK_RINGSZ; i++) { struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i]; io->io_req.br_callback = pci_vtblk_done; io->io_req.br_param = io; io->io_sc = sc; io->io_idx = i; } bcopy(&vtblk_vi_consts, &sc->vbsc_consts, sizeof (vtblk_vi_consts)); if (blockif_candelete(sc->bc)) sc->vbsc_consts.vc_hv_caps |= VTBLK_F_DISCARD; pthread_mutex_init(&sc->vsc_mtx, NULL); /* init virtio softc and virtqueues */ vi_softc_linkup(&sc->vbsc_vs, &sc->vbsc_consts, sc, pi, &sc->vbsc_vq); sc->vbsc_vs.vs_mtx = &sc->vsc_mtx; sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ; /* sc->vbsc_vq.vq_notify = we have no per-queue notify */ /* * If an explicit identifier is not given, create an * identifier using parts of the md5 sum of the filename. */ bzero(sc->vbsc_ident, VTBLK_BLK_ID_BYTES); if ((serial = get_config_value_node(nvl, "serial")) != NULL || (serial = get_config_value_node(nvl, "ser")) != NULL) { strlcpy(sc->vbsc_ident, serial, VTBLK_BLK_ID_BYTES); } else { path = get_config_value_node(nvl, "path"); MD5Init(&mdctx); MD5Update(&mdctx, path, strlen(path)); MD5Final(digest, &mdctx); snprintf(sc->vbsc_ident, VTBLK_BLK_ID_BYTES, "BHYVE-%02X%02X-%02X%02X-%02X%02X", digest[0], digest[1], digest[2], digest[3], digest[4], digest[5]); } /* setup virtio block config space */ sc->vbsc_cfg.vbc_capacity = size / VTBLK_BSIZE; /* 512-byte units */ sc->vbsc_cfg.vbc_size_max = 0; /* not negotiated */ /* * If Linux is presented with a seg_max greater than the virtio queue * size, it can stumble into situations where it violates its own * invariants and panics. For safety, we keep seg_max clamped, paying * heed to the two extra descriptors needed for the header and status * of a request. */ sc->vbsc_cfg.vbc_seg_max = MIN(VTBLK_RINGSZ - 2, BLOCKIF_IOV_MAX); sc->vbsc_cfg.vbc_geometry.cylinders = 0; /* no geometry */ sc->vbsc_cfg.vbc_geometry.heads = 0; sc->vbsc_cfg.vbc_geometry.sectors = 0; sc->vbsc_cfg.vbc_blk_size = sectsz; sc->vbsc_cfg.vbc_topology.physical_block_exp = (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0; sc->vbsc_cfg.vbc_topology.alignment_offset = (sto != 0) ? ((sts - sto) / sectsz) : 0; sc->vbsc_cfg.vbc_topology.min_io_size = 0; sc->vbsc_cfg.vbc_topology.opt_io_size = 0; sc->vbsc_cfg.vbc_writeback = 0; sc->vbsc_cfg.max_discard_sectors = VTBLK_MAX_DISCARD_SECT; sc->vbsc_cfg.max_discard_seg = VTBLK_MAX_DISCARD_SEG; sc->vbsc_cfg.discard_sector_alignment = MAX(sectsz, sts) / VTBLK_BSIZE; /* * Should we move some of this into virtio.c? Could * have the device, class, and subdev_0 as fields in * the virtio constants structure. */ pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK); pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR); pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE); pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_ID_BLOCK); pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR); if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) { blockif_close(sc->bc); free(sc); return (1); } vi_set_io_bar(&sc->vbsc_vs, 0); blockif_register_resize_callback(sc->bc, pci_vtblk_resized, sc); return (0); } static int pci_vtblk_cfgwrite(void *vsc __unused, int offset, int size __unused, uint32_t value __unused) { DPRINTF(("vtblk: write to readonly reg %d", offset)); return (1); } static int pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval) { struct pci_vtblk_softc *sc = vsc; void *ptr; /* our caller has already verified offset and size */ ptr = (uint8_t *)&sc->vbsc_cfg + offset; memcpy(retval, ptr, size); return (0); } static const struct pci_devemu pci_de_vblk = { .pe_emu = "virtio-blk", .pe_init = pci_vtblk_init, .pe_legacy_config = blockif_legacy_config, .pe_barwrite = vi_pci_write, .pe_barread = vi_pci_read, #ifdef BHYVE_SNAPSHOT .pe_snapshot = vi_pci_snapshot, .pe_pause = vi_pci_pause, .pe_resume = vi_pci_resume, #endif }; PCI_EMUL_SET(pci_de_vblk);