#!/bin/bash

set -o pipefail

get_encoded_script()
{
	ENCODED_SCRIPT=`
		if [ "$1" == "vm-default" ]; then
			echo /usr/lib/qubes/dispvm-prerun.sh
		else
			cat "$1"
		fi | base64 -w0` || exit 1
}

if [ $# != 2 -a $# != 3 ] ; then
	echo "usage: $0 domainname savefile_to_be_created [preload script]" >&2
	exit 1
fi
export PATH=$PATH:/sbin:/usr/sbin
if [ $# = 3 ] ; then
	get_encoded_script $3
fi
VMDIR=/var/lib/qubes/appvms/$1
if ! [ -d $VMDIR ] ; then
	echo "$VMDIR does not exist ?" >&2
	exit 1
fi
if ! qvm-start $1 --no-guid --dvm ; then
	exit 1
fi

ID=`xl domid $1`
if [ "$ID" = "" ] ; then 
	echo "cannot get domain id" >&2
	exit 1
fi
echo "Waiting for DVM domainid=$ID ..." >&2
if [ -n "$ENCODED_SCRIPT" ] ; then
	xenstore-write /local/domain/$ID/qubes-save-script "$ENCODED_SCRIPT"
fi
#set -x
xenstore-write /local/domain/$ID/qubes-save-request 1 
xenstore-watch-qubes /local/domain/$ID/device/qubes-used-mem
xenstore-read /local/domain/$ID/qubes-gateway | \
	cut -d . -f 3 | tr -d "\n" > $VMDIR/netvm-id.txt
xl block-detach $1 xvdb
MEM=$(xenstore-read /local/domain/$ID/device/qubes-used-mem)
echo "DVM boot complete, memory used=$MEM. Saving image..." >&2
QMEMMAN_STOP=/var/run/qubes/do-not-membalance
touch $QMEMMAN_STOP
xl mem-set $1 $(($MEM/1000))
sleep 1
touch $2
if ! xl save $1 $2 $VMDIR/$1.conf; then 
	rm -f $QMEMMAN_STOP
	exit 1
fi
rm -f $QMEMMAN_STOP
cd $VMDIR
# Apparently baloon driver isn't effective enough on some kernels - xl
# restore still needs initial memory amount
#sed -i -e "s/^memory.*/memory = $((MEM/1000))/" dvm.conf
tar -Scf saved-cows.tar volatile.img
echo "DVM savefile created successfully." >&2