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, 42 insertions, 0 deletions

diff --git a/tools/testing/selftests/vfio/scripts/lib.sh b/tools/testing/selftests/vfio/scripts/lib.sh
new file mode 100755
index 000000000000..9f05f29c7b86
--- /dev/null
+++ b/tools/testing/selftests/vfio/scripts/lib.sh
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+readonly DEVICES_DIR="${TMPDIR:-/tmp}/vfio-selftests-devices"
+
+function write_to() {
+	# Unfortunately set -x does not show redirects so use echo to manually
+	# tell the user what commands are being run.
+	echo "+ echo \"${2}\" > ${1}"
+	echo "${2}" > ${1}
+}
+
+function get_driver() {
+	if [ -L /sys/bus/pci/devices/${1}/driver ]; then
+		basename $(readlink -m /sys/bus/pci/devices/${1}/driver)
+	fi
+}
+
+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 ${2}
+}
+
+function get_sriov_numvfs() {
+	if [ -f /sys/bus/pci/devices/${1}/sriov_numvfs ]; then
+		cat /sys/bus/pci/devices/${1}/sriov_numvfs
+	fi
+}
+
+function set_driver_override() {
+	write_to /sys/bus/pci/devices/${1}/driver_override ${2}
+}
+
+function clear_driver_override() {
+	set_driver_override ${1} ""
+}