for domain in `virsh list --name`
do
  virsh dommemstat --period 5 $domain
  max=`virsh dominfo $domain | grep Max | grep -Po "\d+"`
  current=`virsh dominfo $domain | grep Used | grep -Po "\d+"`
  unused=`virsh dommemstat $domain | grep unused | grep -Po "\d+"`
  used=$(($current - $unused))
  newfree=$((($max - $used) / 5))
  if test $newfree -gt 524288
  then
    target=$(($newfree + $used))
  else
    target=$((524288 + $used))
  fi
  if test $target -gt $max
  then
    target=$max
  fi
  echo "$domain: $target"
  virsh setmem $domain --size $target
done