[PATCH v7] vfio: selftests: Find devices that have VFIO selftest drivers

[Josh Hilke <jrhilke@google.com>]

Add a new script, list_supported_devices.sh, which prints out the
segment:bus:device.function (SBDF) numbers and names of devices on a
machine that have a VFIO selftest driver. This makes it easier to
determine if the system is capable of running VFIO selftests.

Some of these devices are on the vfio-pci denylist, so vfio-pci refuses
to bind them unless vfio_pci.disable_denylist=Y. The script marks such
devices as DENYLISTED and prints how to enable them, so the user is not
left wondering why the selftests cannot use a "supported" device.

Includes a -q (quiet) argument which prints just the SBDFs of devices
that vfio-pci can bind, so that the output can be passed directly to
tools/testing/selftests/vfio/scripts/setup.sh. Does not print the SBDF
of a device on the denylist.

Examples on a host with eight Intel DSA devices:

$ cat /sys/module/vfio_pci/parameters/disable_denylist
N

$ ./list_supported_devices.sh
0000:6a:01.0 - Intel DSA SPR [8086:0b25] (DENYLISTED)
0000:6f:01.0 - Intel DSA SPR [8086:0b25] (DENYLISTED)
...
vfio-pci does not bind DENYLISTED devices while
vfio_pci.disable_denylist=N. To use them, reload vfio-pci:
  modprobe -r vfio-pci
  modprobe vfio-pci disable_denylist=1
If vfio-pci is built into the kernel, boot with
vfio_pci.disable_denylist=1 instead.

With vfio_pci.disable_denylist=Y, the script lists the same devices with
"(DENYLISTED, but vfio_pci.disable_denylist=Y)", prints no hint, and
includes them in the -q output:

$ ./list_supported_devices.sh -q
0000:6a:01.0
0000:6f:01.0
...

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Josh Hilke <jrhilke@google.com>
---
Changelog

v6 -> v7
- Mark devices on the vfio-pci denylist as DENYLISTED, and say when
  vfio_pci.disable_denylist=Y allows them (Sean)
- Print how to enable denylisted devices when the denylist is on (Sean)
- Leave out denylisted devices from the -q output when the denylist is
  on, so the -q output only has devices that setup.sh can bind (Sean)
- Add the igb and mlx5 devices. Leave out nv_falcon, because its probe
  matches on a BAR0 register (PMC_BOOT_0), not on a PCI ID, so the script
  cannot tell if a given NVIDIA GPU will work
- The mlx5 IDs and names are copied from mlx5st_probe(). They are not
  tested on hardware
- Print a message on stderr when no device is found
- Read device IDs from sysfs instead of lspci, so the script no longer
  needs pciutils

v6: https://lore.kernel.org/kvm/20260602222941.3133236-1-jrhilke@google.com/
v5: https://lore.kernel.org/kvm/20260602185615.3025904-1-jrhilke@google.com/

 tools/testing/selftests/vfio/Makefile         |   1 +
 .../vfio/scripts/list_supported_devices.sh    | 146 ++++++++++++++++++
 2 files changed, 147 insertions(+)
 create mode 100755 tools/testing/selftests/vfio/scripts/list_supported_devices.sh

diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
index 2c32c48db509..160aa989828f 100644
--- a/tools/testing/selftests/vfio/Makefile
+++ b/tools/testing/selftests/vfio/Makefile
@@ -16,6 +16,7 @@ TEST_GEN_PROGS += vfio_pci_sriov_uapi_test
 
 TEST_FILES += scripts/cleanup.sh
 TEST_FILES += scripts/lib.sh
+TEST_FILES += scripts/list_supported_devices.sh
 TEST_FILES += scripts/run.sh
 TEST_FILES += scripts/setup.sh
 
diff --git a/tools/testing/selftests/vfio/scripts/list_supported_devices.sh b/tools/testing/selftests/vfio/scripts/list_supported_devices.sh
new file mode 100755
index 000000000000..d1fad82f704a
--- /dev/null
+++ b/tools/testing/selftests/vfio/scripts/list_supported_devices.sh
@@ -0,0 +1,146 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Devices that have a driver in selftests/vfio/lib/drivers.
+readonly DEVICES=(
+	"8086:0b25,Intel DSA SPR"
+	"8086:11fb,Intel DSA GNR-D"
+	"8086:1212,Intel DSA DMR"
+	"8086:2021,Intel IOAT SKX"
+	"8086:10c9,Intel 82576 Gigabit Ethernet Controller"
+	"15b3:1011,Mellanox Connect-IB"
+	"15b3:1012,Mellanox Connect-IB VF"
+	"15b3:1013,Mellanox ConnectX-4"
+	"15b3:1014,Mellanox ConnectX-4 VF"
+	"15b3:1015,Mellanox ConnectX-4LX"
+	"15b3:1016,Mellanox ConnectX-4LX VF"
+	"15b3:1017,Mellanox ConnectX-5"
+	"15b3:1018,Mellanox ConnectX-5 VF"
+	"15b3:1019,Mellanox ConnectX-5 Ex"
+	"15b3:101a,Mellanox ConnectX-5 Ex VF"
+	"15b3:101b,Mellanox ConnectX-6"
+	"15b3:101c,Mellanox ConnectX-6 VF"
+	"15b3:101d,Mellanox ConnectX-6 Dx"
+	"15b3:101e,Mellanox ConnectX-6 Dx VF"
+	"15b3:101f,Mellanox ConnectX-6 LX"
+	"15b3:1021,Mellanox ConnectX-7"
+	"15b3:1023,Mellanox ConnectX-8"
+	"15b3:1025,Mellanox ConnectX-9"
+	"15b3:1027,Mellanox ConnectX-10"
+	"15b3:2101,Mellanox ConnectX-10 NVLink-C2C"
+	"15b3:a2d2,Mellanox BlueField integrated ConnectX-5"
+	"15b3:a2d3,Mellanox BlueField integrated ConnectX-5 VF"
+	"15b3:a2d6,Mellanox BlueField-2 integrated ConnectX-6 Dx"
+	"15b3:a2dc,Mellanox BlueField-3 integrated ConnectX-7"
+	"15b3:a2df,Mellanox BlueField-4 integrated ConnectX-8"
+)
+
+# Devices in DEVICES that are also on the vfio-pci denylist. The denylist is
+# in vfio_pci_dev_in_denylist() in drivers/vfio/pci/vfio_pci.c.
+readonly DENYLIST=(
+	"8086:0b25"
+)
+
+readonly DISABLE_DENYLIST=/sys/module/vfio_pci/parameters/disable_denylist
+
+function denylisted() {
+	local id
+
+	for id in "${DENYLIST[@]}"; do
+		[ "${id}" = "${1}" ] && return 0
+	done
+
+	return 1
+}
+
+function denylist_enforced() {
+	local value
+
+	read -r value 2>/dev/null < ${DISABLE_DENYLIST}
+	[ "${value}" != "Y" ]
+}
+
+function is_blocked() {
+	denylisted ${1} && denylist_enforced
+}
+
+function device_name() {
+	local entry
+
+	for entry in "${DEVICES[@]}"; do
+		if [ "${entry%%,*}" = "${1}" ]; then
+			echo "${entry#*,}"
+			return 0
+		fi
+	done
+
+	return 1
+}
+
+function denylist_note() {
+	if ! denylisted ${1}; then
+		return
+	elif denylist_enforced; then
+		echo " (DENYLISTED)"
+	else
+		echo " (DENYLISTED, but vfio_pci.disable_denylist=Y)"
+	fi
+}
+
+function print_denylist_hint() {
+	echo "vfio-pci does not bind DENYLISTED devices while"
+	echo "vfio_pci.disable_denylist=N. To use them, reload vfio-pci:"
+	echo "  modprobe -r vfio-pci"
+	echo "  modprobe vfio-pci disable_denylist=1"
+	echo "If vfio-pci is built into the kernel, boot with"
+	echo "vfio_pci.disable_denylist=1 instead."
+}
+
+# Print the segment:bus:device.function numbers of PCI devices that can be used
+# to run VFIO selftests.
+function main() {
+	local blocked=""
+	local quiet=""
+	local found=""
+	local vendor
+	local device
+	local name
+	local bdf
+	local opt
+	local id
+
+	while getopts "q" opt; do
+		case $opt in
+			q) quiet="true" ;;
+			\?) echo "Usage: $0 [-q]" >&2; exit 1 ;;
+		esac
+	done
+
+	for bdf in $(ls /sys/bus/pci/devices); do
+		read -r vendor < /sys/bus/pci/devices/${bdf}/vendor
+		read -r device < /sys/bus/pci/devices/${bdf}/device
+		printf -v id "%04x:%04x" ${vendor} ${device}
+
+		name=$(device_name ${id}) || continue
+		found="true"
+		if is_blocked ${id}; then
+			blocked="true"
+		fi
+
+		if [ -z "${quiet}" ]; then
+			echo "${bdf} - ${name} [${id}]$(denylist_note ${id})"
+		elif ! is_blocked ${id}; then
+			echo "${bdf}"
+		fi
+	done
+
+	if [ "${quiet}" ]; then
+		return 0
+	elif [ -z "${found}" ]; then
+		echo "No devices with a VFIO selftest driver found." >&2
+	elif [ "${blocked}" ]; then
+		print_denylist_hint >&2
+	fi
+}
+
+main "$@"
-- 
2.56.0.455.g6c5a503b38-goog