MFC r272414:

  Merge the following revisions from ^/projects/release-vmimage:

  r272234, r272236, r272262, r272264, r272269, r272271, r272272,
  r272277, r272279, r272376, r272380, r272381, r272392, r272234,
  r272412:

  r272234:
    Initial commit to include virtual machine images as part
    of the FreeBSD release builds.

    This adds a make(1) environment variable requirement,
    WITH_VMIMAGES, which triggers the virtual machine image
    targets when not defined to an empty value.

    Relevant user-driven variables include:

     o VMFORMATS:	The virtual machine image formats to create.
       Valid formats are provided by running 'mkimg --formats'

     o VMSIZE:	The size of the resulting virtual machine
       image.  Typical compression is roughly 140Mb, regardless
       of the target size (10GB, 15GB, 20GB, 40GB sizes have been
       tested with the same result).

     o VMBASE:	The prefix of the virtual machine disk images.
       The VMBASE make(1) environment variable is suffixed with
       each format in VMFORMATS for each individual disk image, as
       well as '.img' for the source UFS filesystem passed to
       mkimg(1).

    This also includes a new script, mk-vmimage.sh, based on how
    the VM images for 10.0-RELEASE, 9.3-RELEASE, and 10.1-RELEASE
    were created (mk-vmimage.sh in ^/user/gjb/thermite/).

    With the order in which the stages need to occur, as well as
    sanity-checking error cases, it makes much more sense to
    execute a shell script called from make(1), using env(1) to
    set specific parameters for the target image than it does to
    do this in make(1) directly.

  r272236:
    Use VMBASE in place of a hard-coded filename in the CLEANFILES
    list.

  r272262:
    Remove a 'set -x' that snuck in during testing.

  r272264:
    release/Makefile:
      Connect the virtual machine image build to the release
      target if WITH_VMIMAGES is set to a non-empty value.

    release/release.sh:
      Add WITH_VMIMAGES to RELEASE_RMAKEFLAGS.

    release/release.conf.sample:
      Add commented entries for tuning the release build if the
      WITH_VMIMAGES make(1) environment variable is set to
      a non-empty value.

  r272269:
    release/Makefile:
      Include .OBJDIR in DESTDIR in the vm-base target.

    release/release.sh:
      Provide the full path to mddev.

  r272271:
    Fix UFS label for the root filesystem.

  r272272:
    Remove comments left in accidentally while testing, so the
    VM /etc/fstab is actually created.

  r272277:
    Remove the UFS label from the root filesystem since it is added
    by mkimg(1) as a gpt label, consistent with the fstab(5) entry.

  r272279:
    Comment cleanup in panic() message when mkimg(1) does not support
    the requested disk image format.

  r272376:
    Separate release/scripts/mk-vmimage.sh to machine-specific
    scripts, making it possible to mimic the functionality for
    non-x86 targets.

    Move echo output if MAKEFLAGS is empty outside of usage().

    Remove TARGET/TARGET_ARCH evaluation.

  r272380:
    Avoid using env(1) to set values passed to mk-vmimage.sh,
    and instead pass the values as arguments to the script,
    making it easier to run this by hand, without 'make release'.

    Add usage_vm_base() and usage_vm_image() usage helpers.

  r272381:
    After evaluating WITH_VMIMAGES is non-empty, ensure
    the mk-vmimage.sh script exists before running it.

  r272392:
    Add WITH_COMPRESSED_VMIMAGES variable, which when set enables
    xz(1) compression of the virtual machine images.

    This is intentionally separate to allow more fine-grained
    tuning over which images are compressed, especially in cases
    where compressing 20GB sparse images can take hours.

  r272412:
    Document the new 'vm-image' target, and associated release.conf
    variables.

  r272413:
    Remove two stray comments added during the initial iterations
    of testing, no longer needed.

Sponsored by:	The FreeBSD Foundation

6 files changed, 530 insertions, 3 deletions

diff --git a/release/Makefile b/release/Makefile
index e59d237..a86e368 100644
--- a/release/Makefile
+++ b/release/Makefile
@@ -23,6 +23,9 @@
 #  WITH_DVD: if set, generate dvd1.iso
 #  WITH_COMPRESSED_IMAGES: if set, compress installation images with xz(1)
 #		(uncompressed images are not removed)
+#  WITH_VMIMAGES: if set, build virtual machine images with the release
+#  WITH_COMPRESSED_VMIMAGES: if set, compress virtual machine disk images
+#  		with xz(1) (extremely time consuming)
 #  TARGET/TARGET_ARCH: architecture of built release
 #
 
@@ -110,6 +113,11 @@ IMAGES+=	uefi-dvd1.iso
 . endif
 .endif
 
+VMTARGETS=	vm-base vm-image
+VMFORMATS?=	vhd vmdk qcow2 raw
+VMSIZE?=	20G
+VMBASE?=	vm
+
 CLEANFILES=	packagesystem *.txz MANIFEST system ${IMAGES}
 .if defined(WITH_COMPRESSED_IMAGES) && !empty(WITH_COMPRESSED_IMAGES)
 . for I in ${IMAGES}
@@ -119,7 +127,16 @@ CLEANFILES+=	${I}.xz
 .if defined(WITH_DVD) && !empty(WITH_DVD)
 CLEANFILES+=	pkg-stage
 .endif
+.if defined(WITH_VMIMAGES) && !empty(WITH_VMIMAGES)
+CLEANFILES+=	${VMBASE}.img
+. for FORMAT in ${VMFORMATS}
+CLEANFILES+=	${VMBASE}.${FORMAT}
+. endfor
+.endif
 CLEANDIRS=	dist ftp release bootonly dvd
+.if defined(WITH_VMIMAGES) && !empty(WITH_VMIMAGES)
+CLEANDIRS+=	${VMTARGETS}
+.endif
 beforeclean:
 	chflags -R noschg .
 .include <bsd.obj.mk>
@@ -297,6 +314,9 @@ ftp: packagesystem
 release:
 	${MAKE} -C ${.CURDIR} ${.MAKEFLAGS} obj
 	${MAKE} -C ${.CURDIR} ${.MAKEFLAGS} ${RELEASE_TARGETS}
+.if defined(WITH_VMIMAGES) && !empty(WITH_VMIMAGES)
+	${MAKE} -C ${.CURDIR} ${.MAKEFLAGS} ${VMTARGETS}
+.endif
 
 install:
 .if defined(DESTDIR) && !empty(DESTDIR)
@@ -311,3 +331,44 @@ install:
 .endfor
 	cd ${DESTDIR} && sha256 ${OSRELEASE}* > ${DESTDIR}/CHECKSUM.SHA256
 	cd ${DESTDIR} && md5 ${OSRELEASE}* > ${DESTDIR}/CHECKSUM.MD5
+.if defined(WITH_VMIMAGES) && !empty(WITH_VMIMAGES)
+	mkdir -p ${DESTDIR}/vmimages
+. for FORMAT in ${VMFORMATS}
+	cp -p ${VMBASE}.${FORMAT} \
+		${DESTDIR}/vmimages/${OSRELEASE}.${FORMAT}
+. endfor
+. if defined(WITH_COMPRESSED_VMIMAGES) && !empty(WITH_COMPRESSED_VMIMAGES)
+# This is very time consuming, so defer it after the images are moved to
+# the DESTDIR.
+.  for FORMAT in ${VMFORMATS}
+	# Don't keep the originals.  There is a copy in ${.OBJDIR} if needed.
+	${XZCMD} ${DESTDIR}/vmimages/${OSRELEASE}.${FORMAT}
+.  endfor
+. endif
+	cd ${DESTDIR}/vmimages && sha256 ${OSRELEASE}* > \
+		${DESTDIR}/vmimages/CHECKSUM.SHA256
+	cd ${DESTDIR}/vmimages && md5 ${OSRELEASE}* > \
+		${DESTDIR}/vmimages/CHECKSUM.MD5
+.endif
+
+vm-base:
+.if defined(WITH_VMIMAGES) && !empty(WITH_VMIMAGES)
+. if exists(${.CURDIR}/${TARGET}/mk-vmimage.sh)
+	env TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH} \
+		${.CURDIR}/${TARGET}/mk-vmimage.sh ${.TARGET} \
+		${VMBASE}.img ${WORLDDIR} ${.OBJDIR}/${.TARGET} ${VMSIZE}
+. endif
+.endif
+	touch ${.TARGET}
+
+vm-image: vm-base
+.if defined(WITH_VMIMAGES) && !empty(WITH_VMIMAGES)
+. if exists(${.CURDIR}/${TARGET}/mk-vmimage.sh)
+.  for FORMAT in ${VMFORMATS}
+	env TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH} \
+		${.CURDIR}/${TARGET}/mk-vmimage.sh ${.TARGET} \
+		${VMBASE}.img ${FORMAT} ${VMBASE}.${FORMAT}
+.  endfor
+. endif
+.endif
+	touch ${.TARGET}
diff --git a/release/amd64/mk-vmimage.sh b/release/amd64/mk-vmimage.sh
new file mode 100755
index 0000000..6ee1482
--- /dev/null
+++ b/release/amd64/mk-vmimage.sh
@@ -0,0 +1,188 @@
+#!/bin/sh
+#-
+# Copyright (c) 2014 The FreeBSD Foundation
+# All rights reserved.
+#
+# This software was developed by Glen Barber under sponsorship
+# from the FreeBSD Foundation.
+#
+# 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.
+#
+# mk-vmimage.sh: Create virtual machine disk images in various formats.
+#
+# $FreeBSD$
+#
+
+PATH="/bin:/usr/bin:/sbin:/usr/sbin"
+export PATH
+
+usage_vm_base() {
+	echo -n "$(basename ${0}) vm-base <base image> <source tree>"
+	echo	" <dest dir> <disk image size>"
+	return 0
+}
+
+usage_vm_image() {
+	echo -n "$(basename ${0}) vm-image <base image> <image format>"
+	echo	" <output image>"
+	return 0
+}
+
+usage() {
+	echo "Usage:"
+	echo "$(basename ${0}) [vm-base|vm-image] [...]"
+	echo
+	usage_vm_base
+	echo
+	usage_vm_image
+	exit 1
+}
+
+panic() {
+	rc="${1}"
+	shift 1
+	msg="${@}"
+	printf "${msg}\n"
+	if [ ! -z "${mddev}" ]; then
+		mdconfig -d -u ${mddev}
+	fi
+	# Do not allow one failure case to chain through any remaining image
+	# builds.
+	exit 0
+}
+
+vm_create_baseimage() {
+	# Creates the UFS root filesystem for the virtual machine disk,
+	# written to the formatted disk image with mkimg(1).
+	#
+	# Arguments:
+	# vm-base <base image> <source tree> <dest dir> <disk image size>
+
+	VMBASE="${1}"
+	WORLDDIR="${2}"
+	DESTDIR="${3}"
+	VMSIZE="${4}"
+
+	if [ -z "${VMBASE}" -o -z "${WORLDDIR}" -o -z "${DESTDIR}" \
+		-o -z "${VMSIZE}" ]; then
+			usage
+	fi
+
+	i=0
+	mkdir -p ${DESTDIR}
+	truncate -s ${VMSIZE} ${VMBASE}
+	mddev=$(mdconfig -f ${VMBASE})
+	newfs -j /dev/${mddev}
+	mount /dev/${mddev} ${DESTDIR}
+	cd ${WORLDDIR} && \
+		make DESTDIR=${DESTDIR} \
+		installworld installkernel distribution || \
+		panic 1 "\n\nCannot install the base system to ${DESTDIR}."
+	chroot ${DESTDIR} /usr/bin/newaliases
+	echo '# Custom /etc/fstab for FreeBSD VM images' \
+		> ${DESTDIR}/etc/fstab
+	echo '/dev/gpt/rootfs	/	ufs	rw	2	2' \
+		>> ${DESTDIR}/etc/fstab
+	echo '/dev/gpt/swapfs	none	swap	sw	0	0' \
+		>> ${DESTDIR}/etc/fstab
+	sync
+	while ! umount ${DESTDIR}; do
+		i=$(( $i + 1 ))
+		if [ $i -ge 10 ]; then
+			# This should never happen.  But, it has happened.
+			msg="Cannot umount(8) ${DESTDIR}\n"
+			msg="${msg}Something has gone horribly wrong."
+			panic 1 "${msg}"
+		fi
+		sleep 1
+	done
+
+	return 0
+}
+
+vm_create_vmdisk() {
+	# Creates the virtual machine disk image from the raw disk image.
+	#
+	# Arguments:
+	# vm-image <base image> <image format> <output image>"
+
+	VMBASE="${1}"
+	FORMAT="${2}"
+	VMIMAGE="${3}"
+
+	if [ -z "${VMBASE}" -o -z "${FORMAT}" -o -z "${VMIMAGE}" ]; then
+		usage
+	fi
+
+	mkimg_version=$(mkimg --version 2>/dev/null | awk '{print $2}')
+
+	# We need mkimg(1) '--version' output, at minimum, to be able to
+	# tell what virtual machine disk image formats are available.
+	# Bail if mkimg(1) reports an empty '--version' value.
+	if [ -z "${mkimg_version}" ]; then
+		msg="Cannot determine mkimg(1) version.\n"
+		msg="${msg}Cannot continue without a known mkimg(1) version."
+		panic 0 "${msg}"
+	fi
+
+	if ! mkimg --formats 2>/dev/null | grep -q ${FORMAT}; then
+		panic 0 "'${FORMAT}' is not supported by this mkimg(1).\n"
+	fi
+
+	case ${FORMAT} in
+		vhd)
+			mkimg_format=vhdf
+			;;
+		*)
+			mkimg_format=${FORMAT}
+			;;
+	esac
+
+	mkimg -f ${mkimg_format} -s gpt \
+		-b /boot/pmbr -p freebsd-boot/bootfs:=/boot/gptboot \
+		-p freebsd-swap/swapfs::1G \
+		-p freebsd-ufs/rootfs:=${VMBASE} \
+		-o ${VMIMAGE}
+
+	return 0
+}
+
+main() {
+	cmd="${1}"
+	shift 1
+
+	case ${cmd} in
+		vm-base)
+			eval vm_create_baseimage "$@" || return 0
+			;;
+		vm-image)
+			eval vm_create_vmdisk "$@" || return 0
+			;;
+		*|\?)
+			usage
+			;;
+	esac
+
+	return 0
+}
+
+main "$@"
diff --git a/release/i386/mk-vmimage.sh b/release/i386/mk-vmimage.sh
new file mode 100755
index 0000000..6ee1482
--- /dev/null
+++ b/release/i386/mk-vmimage.sh
@@ -0,0 +1,188 @@
+#!/bin/sh
+#-
+# Copyright (c) 2014 The FreeBSD Foundation
+# All rights reserved.
+#
+# This software was developed by Glen Barber under sponsorship
+# from the FreeBSD Foundation.
+#
+# 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.
+#
+# mk-vmimage.sh: Create virtual machine disk images in various formats.
+#
+# $FreeBSD$
+#
+
+PATH="/bin:/usr/bin:/sbin:/usr/sbin"
+export PATH
+
+usage_vm_base() {
+	echo -n "$(basename ${0}) vm-base <base image> <source tree>"
+	echo	" <dest dir> <disk image size>"
+	return 0
+}
+
+usage_vm_image() {
+	echo -n "$(basename ${0}) vm-image <base image> <image format>"
+	echo	" <output image>"
+	return 0
+}
+
+usage() {
+	echo "Usage:"
+	echo "$(basename ${0}) [vm-base|vm-image] [...]"
+	echo
+	usage_vm_base
+	echo
+	usage_vm_image
+	exit 1
+}
+
+panic() {
+	rc="${1}"
+	shift 1
+	msg="${@}"
+	printf "${msg}\n"
+	if [ ! -z "${mddev}" ]; then
+		mdconfig -d -u ${mddev}
+	fi
+	# Do not allow one failure case to chain through any remaining image
+	# builds.
+	exit 0
+}
+
+vm_create_baseimage() {
+	# Creates the UFS root filesystem for the virtual machine disk,
+	# written to the formatted disk image with mkimg(1).
+	#
+	# Arguments:
+	# vm-base <base image> <source tree> <dest dir> <disk image size>
+
+	VMBASE="${1}"
+	WORLDDIR="${2}"
+	DESTDIR="${3}"
+	VMSIZE="${4}"
+
+	if [ -z "${VMBASE}" -o -z "${WORLDDIR}" -o -z "${DESTDIR}" \
+		-o -z "${VMSIZE}" ]; then
+			usage
+	fi
+
+	i=0
+	mkdir -p ${DESTDIR}
+	truncate -s ${VMSIZE} ${VMBASE}
+	mddev=$(mdconfig -f ${VMBASE})
+	newfs -j /dev/${mddev}
+	mount /dev/${mddev} ${DESTDIR}
+	cd ${WORLDDIR} && \
+		make DESTDIR=${DESTDIR} \
+		installworld installkernel distribution || \
+		panic 1 "\n\nCannot install the base system to ${DESTDIR}."
+	chroot ${DESTDIR} /usr/bin/newaliases
+	echo '# Custom /etc/fstab for FreeBSD VM images' \
+		> ${DESTDIR}/etc/fstab
+	echo '/dev/gpt/rootfs	/	ufs	rw	2	2' \
+		>> ${DESTDIR}/etc/fstab
+	echo '/dev/gpt/swapfs	none	swap	sw	0	0' \
+		>> ${DESTDIR}/etc/fstab
+	sync
+	while ! umount ${DESTDIR}; do
+		i=$(( $i + 1 ))
+		if [ $i -ge 10 ]; then
+			# This should never happen.  But, it has happened.
+			msg="Cannot umount(8) ${DESTDIR}\n"
+			msg="${msg}Something has gone horribly wrong."
+			panic 1 "${msg}"
+		fi
+		sleep 1
+	done
+
+	return 0
+}
+
+vm_create_vmdisk() {
+	# Creates the virtual machine disk image from the raw disk image.
+	#
+	# Arguments:
+	# vm-image <base image> <image format> <output image>"
+
+	VMBASE="${1}"
+	FORMAT="${2}"
+	VMIMAGE="${3}"
+
+	if [ -z "${VMBASE}" -o -z "${FORMAT}" -o -z "${VMIMAGE}" ]; then
+		usage
+	fi
+
+	mkimg_version=$(mkimg --version 2>/dev/null | awk '{print $2}')
+
+	# We need mkimg(1) '--version' output, at minimum, to be able to
+	# tell what virtual machine disk image formats are available.
+	# Bail if mkimg(1) reports an empty '--version' value.
+	if [ -z "${mkimg_version}" ]; then
+		msg="Cannot determine mkimg(1) version.\n"
+		msg="${msg}Cannot continue without a known mkimg(1) version."
+		panic 0 "${msg}"
+	fi
+
+	if ! mkimg --formats 2>/dev/null | grep -q ${FORMAT}; then
+		panic 0 "'${FORMAT}' is not supported by this mkimg(1).\n"
+	fi
+
+	case ${FORMAT} in
+		vhd)
+			mkimg_format=vhdf
+			;;
+		*)
+			mkimg_format=${FORMAT}
+			;;
+	esac
+
+	mkimg -f ${mkimg_format} -s gpt \
+		-b /boot/pmbr -p freebsd-boot/bootfs:=/boot/gptboot \
+		-p freebsd-swap/swapfs::1G \
+		-p freebsd-ufs/rootfs:=${VMBASE} \
+		-o ${VMIMAGE}
+
+	return 0
+}
+
+main() {
+	cmd="${1}"
+	shift 1
+
+	case ${cmd} in
+		vm-base)
+			eval vm_create_baseimage "$@" || return 0
+			;;
+		vm-image)
+			eval vm_create_vmdisk "$@" || return 0
+			;;
+		*|\?)
+			usage
+			;;
+	esac
+
+	return 0
+}
+
+main "$@"
diff --git a/release/release.conf.sample b/release/release.conf.sample
index 7eea656..4e56244 100644
--- a/release/release.conf.sample
+++ b/release/release.conf.sample
@@ -72,3 +72,24 @@ PORTBRANCH="ports/head@rHEAD"
 ## as TARGET/TARGET_ARCH.
 #CHROOT_MAKEENV=
 
+## Set to a non-empty value to build virtual machine images as part of the
+## release build.
+#WITH_VMIMAGES=
+
+## Set to a non-empty value to compress virtual machine images with xz(1)
+## as part of the release build.
+#WITH_COMPRESSED_VMIMAGES=
+
+## If WITH_VMIMAGES is set to a non-empty value, this is the name of the
+## file to use for the installed userland/kernel.
+#VMBASE="vm"
+
+## If WITH_VMIMAGES is set to a non-empty value, this is the size of the
+## virtual machine disk filesystem.  Valid size values are described in
+## the truncate(1) manual page.
+#VMSIZE="20G"
+
+## If WITH_VMIMAGES is set to a non-empty value, this is a list of disk
+## image formats to create.  Valid values are listed in the mkimg(1)
+## manual page, as well as 'mkimg --formats' output.
+#VMFORMATS="vhdf vmdk qcow2 raw"
diff --git a/release/release.sh b/release/release.sh
index 7960ba8..56e9fff 100755
--- a/release/release.sh
+++ b/release/release.sh
@@ -85,6 +85,11 @@ NOPORTS=
 WITH_DVD=
 WITH_COMPRESSED_IMAGES=
 
+# Set to non-empty value to build virtual machine images as part of
+# the release.
+WITH_VMIMAGES=
+WITH_COMPRESSED_VMIMAGES=
+
 usage() {
 	echo "Usage: $0 [-c release.conf]"
 	exit 1
@@ -168,7 +173,7 @@ CHROOT_DMAKEFLAGS="${CONF_FILES}"
 RELEASE_WMAKEFLAGS="${MAKE_FLAGS} ${WORLD_FLAGS} ${ARCH_FLAGS} ${CONF_FILES}"
 RELEASE_KMAKEFLAGS="${MAKE_FLAGS} ${KERNEL_FLAGS} KERNCONF=\"${KERNEL}\" ${ARCH_FLAGS} ${CONF_FILES}"
 RELEASE_RMAKEFLAGS="${ARCH_FLAGS} KERNCONF=\"${KERNEL}\" ${CONF_FILES} \
-	${DOCPORTS} WITH_DVD=${WITH_DVD}"
+	${DOCPORTS} WITH_DVD=${WITH_DVD} WITH_VMIMAGES=${WITH_VMIMAGES}"
 
 # Force src checkout if configured
 FORCE_SRC_KEY=
@@ -271,4 +276,5 @@ eval chroot ${CHROOTDIR} make -C /usr/src ${RELEASE_KMAKEFLAGS} buildkernel
 eval chroot ${CHROOTDIR} make -C /usr/src/release ${RELEASE_RMAKEFLAGS} \
 	release
 eval chroot ${CHROOTDIR} make -C /usr/src/release ${RELEASE_RMAKEFLAGS} \
-	install DESTDIR=/R WITH_COMPRESSED_IMAGES=${WITH_COMPRESSED_IMAGES}
+	install DESTDIR=/R WITH_COMPRESSED_IMAGES=${WITH_COMPRESSED_IMAGES} \
+	WITH_COMPRESSED_VMIMAGES=${WITH_COMPRESSED_VMIMAGES}
diff --git a/share/man/man7/release.7 b/share/man/man7/release.7
index f3f897e..f73f7ca 100644
--- a/share/man/man7/release.7
+++ b/share/man/man7/release.7
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 11, 2014
+.Dd October 2, 2014
 .Dt RELEASE 7
 .Os
 .Sh NAME
@@ -351,6 +351,61 @@ Set to the target directory within
 to check out
 .Va ${UBOOTSRC}/${UBOOTBRANCH} .
 .El
+.Sh VIRTUAL MACHINE DISK IMAGES
+The following
+.Fa release.conf
+variables are relevant only to virtual machine disk image builds:
+.Bl -tag -width Ev
+.It Va WITH_VMIMAGES
+Set to a non-null value to build virtual machine disk images as part
+of the release build.
+.Va WITH_VMIMAGES
+may also be specified as an envirionment variable passed to
+.Xr make 1 .
+.Pp
+The option requires
+.Xr mkimg 1
+version 20140927 or later.
+.It Va WITH_COMPRESSED_VMIMAGES
+Set to a non-null value to compress the virtual machine disk images with
+.Xr xz 1
+as part of the
+.Cm install
+.Xr make 1
+target.
+Note that compressing virtual machine disk images may take a very long
+time on some systems.
+.It Va VMBASE
+Set to change the name of the resulting virtual machine disk image file.
+The default value is
+.Va vm .
+.It Va VMSIZE
+Set to change the size of the virtual machine disk capacity.
+The default value is
+.Va 20G .
+See
+.Xr truncate 1
+for valid values.
+.Pp
+Virtual machine disk images are, by default, created as sparse images.
+When
+.Va WITH_COMPRESSED_VMIMAGES
+is used, the resulting files compressed with
+.Xr xz 1
+compress to roughly the same size, regardless of the specified disk image
+size.
+.It Va VMFORMATS
+Set to the target virtual disk image format(s) to create.
+By default, the
+.Va vhdf , Va vmdk , Va qcow2 ,
+and
+.Va raw
+formats are created.
+See
+.Xr mkimg 1
+for valid format values
+.Pq requires version 20140927 or later .
+.El
 .Sh MAKEFILE TARGETS
 The release makefile
 .Pq Pa src/release/Makefile
@@ -407,6 +462,14 @@ Creates a directory named
 .Pa ftp
 containing the distribution files used in network installations
 and suitable for upload to an FTP mirror.
+.It Cm vm-image
+Creates virtual machine disk images in various formats.
+The
+.Cm vm-image
+target requires the
+.Va WITH_VMIMAGES
+.Xr make 1
+envirionment variable to be set to a non-null value.
 .El
 .Pp
 Major subtargets called by targets above: