#!/bin/bash

# Copyright 2018 Nikos Giotis, Athens, GR
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''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 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.

VFIO_GROUP=${VFIO_GROUP:-users}

/sbin/modprobe vfio
/sbin/modprobe vfio-pci

for var in "$@"; do
	if [ ! -d "/sys/bus/pci/devices/0000:$var/iommu_group/devices" ]; then
		echo "Cannot find iommu group for $var"
		exit 1
	fi
	for dev in $(ls /sys/bus/pci/devices/0000:$var/iommu_group/devices); do
		read -r vendor < /sys/bus/pci/devices/$dev/vendor
		read -r device < /sys/bus/pci/devices/$dev/device
		if [ -e /sys/bus/pci/devices/$dev/driver ]; then
			echo -n "Unbinding old driver from $dev ... "
			echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
			echo "done."
		fi
		echo -n "New id $vendor:$device to vfio-pci ... "
		echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
		echo "done."
	done
	group_link=$(readlink /sys/bus/pci/devices/0000:$var/iommu_group)
	group=$(basename $group_link)
#	ls -l /dev/vfio/$group
	chown root:$VFIO_GROUP /dev/vfio/$group
	chmod g+rw /dev/vfio/$group
#	ls -l /dev/vfio/$group
done
