vfio: selftests: Split run.sh into separate scripts

Split run.sh into separate scripts (setup.sh, run.sh, cleanup.sh) to
enable multi-device testing, and prepare for VFIO selftests
automatically detecting which devices to use for testing by storing
device metadata on the filesystem.

 - setup.sh takes one or more BDFs as arguments and sets up each device.
   Metadata about each device is stored on the filesystem in the
   directory:

	   ${TMPDIR:-/tmp}/vfio-selftests-devices

   Within this directory is a directory for each BDF, and then files in
   those directories that cleanup.sh uses to cleanup the device.

 - run.sh runs a selftest by passing it the BDFs of all set up devices.

 - cleanup.sh takes zero or more BDFs as arguments and cleans up each
   device. If no BDFs are provided, it cleans up all devices.

This split enables multi-device testing by allowing multiple BDFs to be
set up and passed into tests:

For example:

  $ tools/testing/selftests/vfio/scripts/setup.sh <BDF1> <BDF2>
  $ tools/testing/selftests/vfio/scripts/setup.sh <BDF3>
  $ tools/testing/selftests/vfio/scripts/run.sh echo
  <BDF1> <BDF2> <BDF3>
  $ tools/testing/selftests/vfio/scripts/cleanup.sh

In the future, VFIO selftests can automatically detect set up devices by
inspecting ${TMPDIR:-/tmp}/vfio-selftests-devices. This will avoid the
need for the run.sh script.

Reviewed-by: Alex Mastro <amastro@fb.com>
Tested-by: Alex Mastro <amastro@fb.com>
Reviewed-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20251126231733.3302983-3-dmatlack@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

1 files changed, 6 insertions, 99 deletions

diff --git a/tools/testing/selftests/vfio/scripts/run.sh b/tools/testing/selftests/vfio/scripts/run.sh
index 0476b6d7adc3..91fd38f9f6f6 100755
--- a/tools/testing/selftests/vfio/scripts/run.sh
+++ b/tools/testing/selftests/vfio/scripts/run.sh
@@ -1,109 +1,16 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-# Global variables initialized in main() and then used during cleanup() when
-# the script exits.
-declare DEVICE_BDF
-declare NEW_DRIVER
-declare OLD_DRIVER
-declare OLD_NUMVFS
-declare DRIVER_OVERRIDE
-
-function write_to() {
-	# Unfortunately set -x does not show redirects so use echo to manually
-	# tell the user what commands are being run.
-	echo "+ echo \"${2}\" > ${1}"
-	echo "${2}" > ${1}
-}
-
-function bind() {
-	write_to /sys/bus/pci/drivers/${2}/bind ${1}
-}
-
-function unbind() {
-	write_to /sys/bus/pci/drivers/${2}/unbind ${1}
-}
-
-function set_sriov_numvfs() {
-	write_to /sys/bus/pci/devices/${1}/sriov_numvfs ${2}
-}
-
-function set_driver_override() {
-	write_to /sys/bus/pci/devices/${1}/driver_override ${2}
-}
-
-function clear_driver_override() {
-	set_driver_override ${1} ""
-}
-
-function cleanup() {
-	if [ "${NEW_DRIVER}"      ]; then unbind ${DEVICE_BDF} ${NEW_DRIVER} ; fi
-	if [ "${DRIVER_OVERRIDE}" ]; then clear_driver_override ${DEVICE_BDF} ; fi
-	if [ "${OLD_DRIVER}"      ]; then bind ${DEVICE_BDF} ${OLD_DRIVER} ; fi
-	if [ "${OLD_NUMVFS}"      ]; then set_sriov_numvfs ${DEVICE_BDF} ${OLD_NUMVFS} ; fi
-}
-
-function usage() {
-	echo "usage: $0 [-d segment:bus:device.function] [-s] [-h] [cmd ...]" >&2
-	echo >&2
-	echo "  -d: The BDF of the device to use for the test (required)" >&2
-	echo "  -h: Show this help message" >&2
-	echo "  -s: Drop into a shell rather than running a command" >&2
-	echo >&2
-	echo "   cmd: The command to run and arguments to pass to it." >&2
-	echo "        Required when not using -s. The SBDF will be " >&2
-	echo "        appended to the argument list." >&2
-	exit 1
-}
+source $(dirname -- "${BASH_SOURCE[0]}")/lib.sh
 
 function main() {
-	local shell
-
-	while getopts "d:hs" opt; do
-		case $opt in
-			d) DEVICE_BDF="$OPTARG" ;;
-			s) shell=true ;;
-			*) usage ;;
-		esac
-	done
-
-	# Shift past all optional arguments.
-	shift $((OPTIND - 1))
-
-	# Check that the user passed in the command to run.
-	[ ! "${shell}" ] && [ $# = 0 ] && usage
-
-	# Check that the user passed in a BDF.
-	[ "${DEVICE_BDF}" ] || usage
-
-	trap cleanup EXIT
-	set -e
+	local device_bdfs=$(ls ${DEVICES_DIR})
 
-	test -d /sys/bus/pci/devices/${DEVICE_BDF}
-
-	if [ -f /sys/bus/pci/devices/${DEVICE_BDF}/sriov_numvfs ]; then
-		OLD_NUMVFS=$(cat /sys/bus/pci/devices/${DEVICE_BDF}/sriov_numvfs)
-		set_sriov_numvfs ${DEVICE_BDF} 0
-	fi
-
-	if [ -L /sys/bus/pci/devices/${DEVICE_BDF}/driver ]; then
-		OLD_DRIVER=$(basename $(readlink -m /sys/bus/pci/devices/${DEVICE_BDF}/driver))
-		unbind ${DEVICE_BDF} ${OLD_DRIVER}
+	if [ -z "${device_bdfs}" ]; then
+		echo "No devices found, skipping."
+		exit 4
 	fi
 
-	set_driver_override ${DEVICE_BDF} vfio-pci
-	DRIVER_OVERRIDE=true
-
-	bind ${DEVICE_BDF} vfio-pci
-	NEW_DRIVER=vfio-pci
-
-	echo
-	if [ "${shell}" ]; then
-		echo "Dropping into ${SHELL} with VFIO_SELFTESTS_BDF=${DEVICE_BDF}"
-		VFIO_SELFTESTS_BDF=${DEVICE_BDF} ${SHELL}
-	else
-		"$@" ${DEVICE_BDF}
-	fi
-	echo
+	"$@" ${device_bdfs}
 }
 
 main "$@"