diff --git a/usr.sbin/bhyve/block_if.c b/usr.sbin/bhyve/block_if.c
index b8b27a659df8..bcb1617d4c09 100644
--- a/usr.sbin/bhyve/block_if.c
+++ b/usr.sbin/bhyve/block_if.c
@@ -85,6 +85,7 @@ struct blockif_ctxt {
 	int			bc_magic;
 	int			bc_fd;
 	int			bc_ischr;
+	int			bc_isgeom;
 	int			bc_candelete;
 	int			bc_rdonly;
 	off_t			bc_size;
@@ -198,27 +199,93 @@ blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be)
 }
 
 static void
-blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be)
+blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf)
 {
 	struct blockif_req *br;
 	off_t arg[2];
-	int err;
+	ssize_t clen, len, off, boff, voff;
+	int i, err;
 
 	br = be->be_req;
+	if (br->br_iovcnt <= 1)
+		buf = NULL;
 	err = 0;
-
 	switch (be->be_op) {
 	case BOP_READ:
-		if (preadv(bc->bc_fd, br->br_iov, br->br_iovcnt,
-			   br->br_offset) < 0)
-			err = errno;
+		if (buf == NULL) {
+			if ((len = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt,
+				   br->br_offset)) < 0)
+				err = errno;
+			else
+				br->br_resid -= len;
+			break;
+		}
+		i = 0;
+		off = voff = 0;
+		while (br->br_resid > 0) {
+			len = MIN(br->br_resid, MAXPHYS);
+			if (pread(bc->bc_fd, buf, len, br->br_offset +
+			    off) < 0) {
+				err = errno;
+				break;
+			}
+			boff = 0;
+			do {
+				clen = MIN(len - boff, br->br_iov[i].iov_len -
+				    voff);
+				memcpy(br->br_iov[i].iov_base + voff,
+				    buf + boff, clen);
+				if (clen < br->br_iov[i].iov_len - voff)
+					voff += clen;
+				else {
+					i++;
+					voff = 0;
+				}
+				boff += clen;
+			} while (boff < len);
+			off += len;
+			br->br_resid -= len;
+		}
 		break;
 	case BOP_WRITE:
-		if (bc->bc_rdonly)
+		if (bc->bc_rdonly) {
 			err = EROFS;
-		else if (pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt,
-			     br->br_offset) < 0)
-			err = errno;
+			break;
+		}
+		if (buf == NULL) {
+			if ((len = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt,
+				    br->br_offset)) < 0)
+				err = errno;
+			else
+				br->br_resid -= len;
+			break;
+		}
+		i = 0;
+		off = voff = 0;
+		while (br->br_resid > 0) {
+			len = MIN(br->br_resid, MAXPHYS);
+			boff = 0;
+			do {
+				clen = MIN(len - boff, br->br_iov[i].iov_len -
+				    voff);
+				memcpy(buf + boff,
+				    br->br_iov[i].iov_base + voff, clen);
+				if (clen < br->br_iov[i].iov_len - voff)
+					voff += clen;
+				else {
+					i++;
+					voff = 0;
+				}
+				boff += clen;
+			} while (boff < len);
+			if (pwrite(bc->bc_fd, buf, len, br->br_offset +
+			    off) < 0) {
+				err = errno;
+				break;
+			}
+			off += len;
+			br->br_resid -= len;
+		}
 		break;
 	case BOP_FLUSH:
 		if (bc->bc_ischr) {
@@ -234,9 +301,11 @@ blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be)
 			err = EROFS;
 		else if (bc->bc_ischr) {
 			arg[0] = br->br_offset;
-			arg[1] = br->br_iov[0].iov_len;
+			arg[1] = br->br_resid;
 			if (ioctl(bc->bc_fd, DIOCGDELETE, arg))
 				err = errno;
+			else
+				br->br_resid = 0;
 		} else
 			err = EOPNOTSUPP;
 		break;
@@ -256,15 +325,20 @@ blockif_thr(void *arg)
 	struct blockif_ctxt *bc;
 	struct blockif_elem *be;
 	pthread_t t;
+	uint8_t *buf;
 
 	bc = arg;
+	if (bc->bc_isgeom)
+		buf = malloc(MAXPHYS);
+	else
+		buf = NULL;
 	t = pthread_self();
 
 	pthread_mutex_lock(&bc->bc_mtx);
 	for (;;) {
 		while (blockif_dequeue(bc, t, &be)) {
 			pthread_mutex_unlock(&bc->bc_mtx);
-			blockif_proc(bc, be);
+			blockif_proc(bc, be, buf);
 			pthread_mutex_lock(&bc->bc_mtx);
 			blockif_complete(bc, be);
 		}
@@ -275,6 +349,8 @@ blockif_thr(void *arg)
 	}
 	pthread_mutex_unlock(&bc->bc_mtx);
 
+	if (buf)
+		free(buf);
 	pthread_exit(NULL);
 	return (NULL);
 }
@@ -315,13 +391,14 @@ struct blockif_ctxt *
 blockif_open(const char *optstr, const char *ident)
 {
 	char tname[MAXCOMLEN + 1];
+	char name[MAXPATHLEN];
 	char *nopt, *xopts;
 	struct blockif_ctxt *bc;
 	struct stat sbuf;
 	struct diocgattr_arg arg;
 	off_t size, psectsz, psectoff;
 	int extra, fd, i, sectsz;
-	int nocache, sync, ro, candelete;
+	int nocache, sync, ro, candelete, geom;
 
 	pthread_once(&blockif_once, blockif_init);
 
@@ -375,7 +452,7 @@ blockif_open(const char *optstr, const char *ident)
         size = sbuf.st_size;
 	sectsz = DEV_BSIZE;
 	psectsz = psectoff = 0;
-	candelete = 0;
+	candelete = geom = 0;
 	if (S_ISCHR(sbuf.st_mode)) {
 		if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 ||
 		    ioctl(fd, DIOCGSECTORSIZE, &sectsz)) {
@@ -391,6 +468,8 @@ blockif_open(const char *optstr, const char *ident)
 		arg.len = sizeof(arg.value.i);
 		if (ioctl(fd, DIOCGATTR, &arg) == 0)
 			candelete = arg.value.i;
+		if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0)
+			geom = 1;
 	} else
 		psectsz = sbuf.st_blksize;
 
@@ -403,6 +482,7 @@ blockif_open(const char *optstr, const char *ident)
 	bc->bc_magic = BLOCKIF_SIG;
 	bc->bc_fd = fd;
 	bc->bc_ischr = S_ISCHR(sbuf.st_mode);
+	bc->bc_isgeom = geom;
 	bc->bc_candelete = candelete;
 	bc->bc_rdonly = ro;
 	bc->bc_size = size;
diff --git a/usr.sbin/bhyve/block_if.h b/usr.sbin/bhyve/block_if.h
index 1cb7c8048688..8e63407e36b8 100644
--- a/usr.sbin/bhyve/block_if.h
+++ b/usr.sbin/bhyve/block_if.h
@@ -45,6 +45,7 @@ struct blockif_req {
 	struct iovec	br_iov[BLOCKIF_IOV_MAX];
 	int		br_iovcnt;
 	off_t		br_offset;
+	ssize_t		br_resid;
 	void		(*br_callback)(struct blockif_req *req, int err);
 	void		*br_param;
 };
diff --git a/usr.sbin/bhyve/pci_ahci.c b/usr.sbin/bhyve/pci_ahci.c
index 87a1cead20da..95cfdd9d2ba3 100644
--- a/usr.sbin/bhyve/pci_ahci.c
+++ b/usr.sbin/bhyve/pci_ahci.c
@@ -571,6 +571,7 @@ ahci_build_iov(struct ahci_port *p, struct ahci_ioreq *aior,
 	}
 
 	breq->br_iovcnt = j;
+	breq->br_resid = todo;
 	aior->done += todo;
 	aior->more = (aior->done < aior->len && i < prdtl);
 }
@@ -776,8 +777,7 @@ next:
 
 	breq = &aior->io_req;
 	breq->br_offset = elba * blockif_sectsz(p->bctx);
-	breq->br_iovcnt = 1;
-	breq->br_iov[0].iov_len = elen * blockif_sectsz(p->bctx);
+	breq->br_resid = elen * blockif_sectsz(p->bctx);
 
 	/*
 	 * Mark this command in-flight.
diff --git a/usr.sbin/bhyve/pci_virtio_block.c b/usr.sbin/bhyve/pci_virtio_block.c
index 967b52855b4c..35daa1f3921e 100644
--- a/usr.sbin/bhyve/pci_virtio_block.c
+++ b/usr.sbin/bhyve/pci_virtio_block.c
@@ -198,7 +198,7 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
 	struct pci_vtblk_ioreq *io;
 	int i, n;
 	int err;
-	int iolen;
+	ssize_t iolen;
 	int writeop, type;
 	off_t offset;
 	struct iovec iov[BLOCKIF_IOV_MAX + 2];
@@ -246,8 +246,9 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
 		assert(((flags[i] & VRING_DESC_F_WRITE) == 0) == writeop);
 		iolen += iov[i].iov_len;
 	}
+	io->io_req.br_resid = iolen;
 
-	DPRINTF(("virtio-block: %s op, %d bytes, %d segs, offset %ld\n\r", 
+	DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld\n\r", 
 		 writeop ? "write" : "read/ident", iolen, i - 1, offset));
 
 	switch (type) {