--- /home/grehan/proj/freebsd/12/usr.sbin/bhyve/block_if.h	2016-07-10 14:02:23.431522000 -0700
+++ block_if.h	2017-05-21 13:12:09.557407000 -0700
@@ -39,7 +39,7 @@
 #include <sys/uio.h>
 #include <sys/unistd.h>
 
-#define BLOCKIF_IOV_MAX		33	/* not practical to be IOV_MAX */
+#define BLOCKIF_IOV_MAX		128	/* not practical to be IOV_MAX */
 
 struct blockif_req {
 	struct iovec	br_iov[BLOCKIF_IOV_MAX];
--- /home/grehan/proj/freebsd/12/usr.sbin/bhyve/block_if.c	2017-02-15 10:18:53.495226000 -0800
+++ block_if.c	2017-05-21 13:07:56.247895000 -0700
@@ -824,7 +824,7 @@
 {
 
 	assert(bc->bc_magic == BLOCKIF_SIG);
-	return (BLOCKIF_MAXREQ - 1);
+	return (BLOCKIF_MAXREQ - BLOCKIF_NUMTHR);
 }
 
 int
--- /home/grehan/proj/freebsd/12/usr.sbin/bhyve/pci_virtio_block.c	2016-07-10 14:02:23.447636000 -0700
+++ pci_virtio_block.c	2017-05-21 13:33:36.041573000 -0700
@@ -348,7 +348,7 @@
 	/* setup virtio block config space */
 	sc->vbsc_cfg.vbc_capacity = size / DEV_BSIZE; /* 512-byte units */
 	sc->vbsc_cfg.vbc_size_max = 0;	/* not negotiated */
-	sc->vbsc_cfg.vbc_seg_max = BLOCKIF_IOV_MAX;
+	sc->vbsc_cfg.vbc_seg_max = MIN(BLOCKIF_IOV_MAX, VTBLK_RINGSZ);
 	sc->vbsc_cfg.vbc_geometry.cylinders = 0;	/* no geometry */
 	sc->vbsc_cfg.vbc_geometry.heads = 0;
 	sc->vbsc_cfg.vbc_geometry.sectors = 0;