post_install() {
  if ! getent group kvm &>/dev/null; then
    groupadd kvm -f -g 78 >/dev/null
  fi

  # trigger events on modules files when already loaded
  for _f in /sys/devices/virtual/misc/{kvm,vhost-net}; do
    [[ -e "$_f" ]] &&  udevadm trigger "$_f"
  done
  :
}

post_upgrade() {
  post_install
}

post_remove() {
  if getent group kvm &>/dev/null; then
    groupdel kvm >/dev/null
  fi
}