Index: release/scripts/mk-vmimage.sh
===================================================================
--- release/scripts/mk-vmimage.sh
+++ release/scripts/mk-vmimage.sh
@@ -52,6 +52,9 @@
 			d)
 				DESTDIR="${OPTARG}"
 				;;
+			F)
+				VMFSTYPE="${OPTARG}"
+				;;
 			f)
 				VMFORMAT="${OPTARG}"
 				;;
@@ -91,6 +94,10 @@
 
 	if [ ! -z "${VMCONFIG}" ] && [ ! -c "${VMCONFIG}" ]; then
 		. "${VMCONFIG}"
+	fi
+
+	if [ ! -z "${VMFSTYPE}" ] && [ ! -c "${VMFSTYPE}" ]; then
+		. "${VMFSTYPE}"
 	fi
 
 	case ${TARGET}:${TARGET_ARCH} in
Index: release/tools/vmimage.subr
===================================================================
--- release/tools/vmimage.subr
+++ release/tools/vmimage.subr
@@ -76,8 +76,7 @@
 }
 
 vm_create_base() {
-	# Creates the UFS root filesystem for the virtual machine disk,
-	# written to the formatted disk image with mkimg(1).
+	# Creates temporary UFS root filesystem for the virtual machine disk.
 
 	mkdir -p ${DESTDIR}
 	truncate -s ${VMSIZE} ${VMBASE}
Index: release/tools/zfs.conf
===================================================================
--- /dev/null
+++ release/tools/zfs.conf
@@ -0,0 +1,180 @@
+#!/bin/sh
+#-
+# Copyright (c) 2013-2016 Allan Jude
+# Copyright (c) 2013-2018 Devin Teske
+# 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, 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 AND CONTRIBUTORS ``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 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.
+#
+# $FreeBSD$
+#
+
+: ${ZFSBOOT_POOL_NAME:=zroot}
+: ${ZFSBOOT_BEROOT_NAME:=ROOT}
+: ${ZFSBOOT_BOOTFS_NAME:=default}
+
+# Stolen from bsdconfig
+# str_replaceall $string $find $replace [$var_to_set]
+#
+# Replace all occurrences of $find in $string with $replace. If $var_to_set is
+# either missing or NULL, the variable name is produced on standard out for
+# capturing in a sub-shell (which is less recommended due to performance
+# degradation).
+#
+str_replaceall()
+{
+	local __left="" __right="$1"
+	local __find="$2" __replace="$3" __var_to_set="$4"
+	while :; do
+		case "$__right" in *$__find*)
+			__left="$__left${__right%%$__find*}$__replace"
+			__right="${__right#*$__find}"
+			continue
+		esac
+		break
+	done
+	__left="$__left${__right#*$__find}"
+	if [ "$__var_to_set" ]; then
+		setvar "$__var_to_set" "$__left"
+	else
+		echo "$__left"
+	fi
+}
+
+create_zfs_be_datasets() {
+	local OPT OPTSTR
+
+	: ${ZFS_DATASETS:="
+		# DATASET	OPTIONS (space separated)
+
+		# Boot Environment [BE] root and default boot dataset
+		/$ZFSBOOT_BEROOT_NAME				mountpoint=none
+		/$ZFSBOOT_BEROOT_NAME/$ZFSBOOT_BOOTFS_NAME	mountpoint=/
+
+		# Compress /tmp, allow exec but not setuid
+		/tmp		mountpoint=/tmp exec=on setuid=off
+
+		# Don't mount /usr so that 'base' files go to the BEROOT
+		/usr		mountpoint=/usr canmount=off
+
+		# Home directories separated so they are common to all BEs
+		/usr/home	# NB: /home is a symlink to /usr/home
+
+		# Ports tree
+		/usr/ports	setuid=off
+
+		# Source tree (compressed)
+		/usr/src
+
+		# Create /var and friends
+		/var		mountpoint=/var canmount=off
+		/var/audit	exec=off setuid=off
+		/var/crash	exec=off setuid=off
+		/var/log	exec=off setuid=off
+		/var/mail	atime=on
+		/var/tmp	setuid=off
+	"}
+
+	echo "$ZFSBOOT_DATASETS" | while read dataset options; do
+		# Skip blank lines and comments
+		case "$dataset" in "#"*|"") continue; esac
+		# Remove potential inline comments in options
+		options="${options%%#*}"
+		# Replace tabs with spaces
+		str_replaceall "$options" "	" " " options
+		# Reduce contiguous runs of space to one single space
+		oldoptions=
+		while [ "$oldoptions" != "$options" ]; do
+			oldoptions="$options"
+			str_replaceall "$options" "  " " " options
+		done
+		# Replace both commas and spaces with ` -o '
+		str_replaceall "$options" "[ ,]" " -o " options
+		# Create the dataset with desired options
+		zfs create ${options:+-o $options} "${ZFSBOOT_POOL_NAME}$dataset" ||
+		    err 1 "Dataset creation failed"
+	done
+}
+
+create_zpool() {
+	mddev=$1
+
+	zpool create \
+		-O mountpoint=/ \
+		-O canmount=noauto \
+		-O compression=on \
+		-O atime=off \
+		-R ${DESTDIR}/new ${ZFSBOOT_POOL_NAME} /dev/${mddev}
+
+	create_zfs_be_datasets
+}
+
+vm_copy_base() {
+	mkdir -p ${DESTDIR}/old
+	mdold=$(mdconfig -f ${VMBASE})
+	mount /dev/${mdold} ${DESTDIR}/old
+
+	truncate -s ${VMSIZE} ${VMBASE}.tmp
+	mkdir -p ${DESTDIR}/new
+	mdnew=$(mdconfig -f ${VMBASE}.tmp)
+
+	create_zpool ${mddev}
+
+	tar -cf- -C ${DESTDIR}/old . | tar -xUf- -C ${DESTDIR}/new
+
+	umount_loop /dev/${mdold}
+	rmdir ${DESTDIR}/old
+	mdconfig -d -u ${mdold}
+
+	umount_loop /dev/${mdnew}
+	rmdir ${DESTDIR}/new
+	zpool export ${ZFSBOOT_POOL_NAME}
+	mv ${VMBASE}.tmp ${VMBASE}
+}
+
+write_partition_layout() {
+	if [ -z "${NOSWAP}" ]; then
+		SWAPOPT="-p freebsd-swap/swapfs::${SWAPSIZE}"
+	fi
+
+	BOOTFILES="$(env TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH} \
+		WITH_UNIFIED_OBJDIR=yes \
+		make -C ${WORLDDIR}/stand -V .OBJDIR)"
+	BOOTFILES="$(realpath ${BOOTFILES})"
+
+	case "${TARGET}:${TARGET_ARCH}" in
+		amd64:amd64 | i386:i386)
+			mkimg -s gpt -f ${VMFORMAT} \
+				-b ${BOOTFILES}/i386/pmbr/pmbr \
+				-p freebsd-boot/bootfs:=${BOOTFILES}/i386/gptzfsboot/gptzfsboot \
+				${SWAPOPT} \
+				-p freebsd-zfs/rootfs:=${VMBASE} \
+				-o ${VMIMAGE}
+			;;
+		*)
+			# ENOTSUPP
+			return 1
+			;;
+	esac
+
+	return 0
+}