[PATCH net-next v7 12/12] selftests: microchip: add test for QoS support on KSZ9477 switch family

[Oleksij Rempel]

Add tests covering following functionality on KSZ9477 switch family:
- default port priority
- global DSCP to Internal Priority Mapping
- apptrust configuration

This script was tested on KSZ9893R

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
 .../drivers/net/microchip/ksz9477_qos.sh      | 668 ++++++++++++++++++
 1 file changed, 668 insertions(+)
 create mode 100755 tools/testing/selftests/drivers/net/microchip/ksz9477_qos.sh

diff --git a/tools/testing/selftests/drivers/net/microchip/ksz9477_qos.sh b/tools/testing/selftests/drivers/net/microchip/ksz9477_qos.sh
new file mode 100755
index 0000000000000..82be5d0133301
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/microchip/ksz9477_qos.sh
@@ -0,0 +1,668 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2024 Pengutronix, Oleksij Rempel <kernel@xxxxxxxxxxxxxx>
+
+# The script is adopted to work with the Microchip KSZ switch driver.
+
+ETH_FCS_LEN=4
+
+WAIT_TIME=1
+NUM_NETIFS=4
+REQUIRE_JQ="yes"
+REQUIRE_MZ="yes"
+STABLE_MAC_ADDRS=yes
+NETIF_CREATE=no
+lib_dir=$(dirname $0)/../../../net/forwarding
+source $lib_dir/tc_common.sh
+source $lib_dir/lib.sh
+
+require_command dcb
+
+h1=${NETIFS[p1]}
+swp1=${NETIFS[p2]}
+swp2=${NETIFS[p3]}
+h2=${NETIFS[p4]}
+
+H1_IPV4="192.0.2.1"
+H2_IPV4="192.0.2.2"
+H1_IPV6="2001:db8:1::1"
+H2_IPV6="2001:db8:1::2"
+
+# On h1_ and h2_create do not set IP addresses to avoid interaction with the
+# system, to keep packet counters clean.
+h1_create()
+{
+	simple_if_init $h1
+	sysctl_set net.ipv6.conf.${h1}.disable_ipv6 1
+	# Get the MAC address of the interface to use it with mausezahn
+	h1_mac=$(ip -j link show dev ${h1} | jq -e '.[].address')
+}
+
+h1_destroy()
+{
+	sysctl_restore net.ipv6.conf.${h1}.disable_ipv6
+	simple_if_fini $h1
+}
+
+h2_create()
+{
+	simple_if_init $h2
+	sysctl_set net.ipv6.conf.${h2}.disable_ipv6 1
+	h2_mac=$(ip -j link show dev ${h2} | jq -e '.[].address')
+}
+
+h2_destroy()
+{
+	sysctl_restore net.ipv6.conf.${h2}.disable_ipv6
+	simple_if_fini $h2
+}
+
+switch_create()
+{
+	ip link set ${swp1} up
+	ip link set ${swp2} up
+	sysctl_set net.ipv6.conf.${swp1}.disable_ipv6 1
+	sysctl_set net.ipv6.conf.${swp2}.disable_ipv6 1
+
+	# Ports should trust VLAN PCP even with vlan_filtering=0
+	ip link add br0 type bridge
+	ip link set ${swp1} master br0
+	ip link set ${swp2} master br0
+	ip link set br0 up
+	sysctl_set net.ipv6.conf.br0.disable_ipv6 1
+}
+
+switch_destroy()
+{
+	sysctl_restore net.ipv6.conf.${swp2}.disable_ipv6
+	sysctl_restore net.ipv6.conf.${swp1}.disable_ipv6
+
+	ip link del br0
+}
+
+setup_prepare()
+{
+	vrf_prepare
+
+	h1_create
+	h2_create
+	switch_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	h2_destroy
+	h1_destroy
+	switch_destroy
+
+	vrf_cleanup
+}
+
+set_apptrust_order()
+{
+	local if_name=$1
+	local order=$2
+
+	dcb apptrust set dev ${if_name} order ${order}
+}
+
+# Function to extract a specified field from a given JSON stats string
+extract_network_stat() {
+	local stats_json=$1
+	local field_name=$2
+
+	echo $(echo "$stats_json" | jq -r "$field_name")
+}
+
+run_test()
+{
+	local test_name=$1;
+	local apptrust_order=$2;
+	local port_prio=$3;
+	local dscp_ipv=$4;
+	local dscp=$5;
+	local have_vlan=$6;
+	local pcp_ipv=$7;
+	local vlan_pcp=$8;
+	local ip_v6=$9
+
+	local rx_ipv
+	local tx_ipv
+
+	RET=0
+
+	# Send some packet to populate the switch MAC table
+	$MZ ${h2} -a ${h2_mac} -b ${h1_mac} -p 64 -t icmp echores -c 1
+
+	# Based on the apptrust order, set the expected Internal Priority values
+	# for the RX and TX paths.
+	if [ "${apptrust_order}" == "" ]; then
+		echo "Apptrust order not set."
+		rx_ipv=${port_prio}
+		tx_ipv=${port_prio}
+	elif [ "${apptrust_order}" == "dscp" ]; then
+		echo "Apptrust order is DSCP."
+		rx_ipv=${dscp_ipv}
+		tx_ipv=${dscp_ipv}
+	elif [ "${apptrust_order}" == "pcp" ]; then
+		echo "Apptrust order is PCP."
+		rx_ipv=${pcp_ipv}
+		tx_ipv=${pcp_ipv}
+	elif [ "${apptrust_order}" == "pcp dscp" ]; then
+		echo "Apptrust order is PCP DSCP."
+		if [ ${have_vlan} -eq 1 ]; then
+			rx_ipv=$((dscp_ipv > pcp_ipv ? dscp_ipv : pcp_ipv))
+			tx_ipv=${pcp_ipv}
+		else
+			rx_ipv=${dscp_ipv}
+			tx_ipv=${dscp_ipv}
+		fi
+	else
+		RET=1
+		echo "Error: Unknown apptrust order ${apptrust_order}"
+		log_test "${test_name}"
+		return
+	fi
+
+	# Most/all? of the KSZ switches do not provide per-TC counters. There
+	# are only tx_hi and rx_hi counters, which are used to count packets
+	# which are considered as high priority and most likely not assigned
+	# to the queue 0.
+	# On the ingress path, packets seem to get high priority status
+	# independently of the DSCP or PCP global mapping. On the egress path,
+	# the high priority status is assigned based on the DSCP or PCP global
+	# map configuration.
+	# The thresholds for the high priority status are not documented, but
+	# it seems that the switch considers packets as high priority on the
+	# ingress path if detected Internal Priority is greater than 0. On the
+	# egress path, the switch considers packets as high priority if
+	# detected Internal Priority is greater than 1.
+	if [ ${rx_ipv} -ge 1 ]; then
+		local expect_rx_high_prio=1
+	else
+		local expect_rx_high_prio=0
+	fi
+
+	if [ ${tx_ipv} -ge 2 ]; then
+		local expect_tx_high_prio=1
+	else
+		local expect_tx_high_prio=0
+	fi
+
+	# Use ip tool to get the current switch packet counters. ethool stats
+	# need to be recalculated to get the correct values.
+	local swp1_stats=$(ip -s -j link show dev ${swp1})
+	local swp2_stats=$(ip -s -j link show dev ${swp2})
+	local swp1_rx_packets_before=$(extract_network_stat "$swp1_stats" \
+				       '.[0].stats64.rx.packets')
+	local swp1_rx_bytes_before=$(extract_network_stat "$swp1_stats" \
+				     '.[0].stats64.rx.bytes')
+	local swp2_tx_packets_before=$(extract_network_stat "$swp2_stats" \
+				       '.[0].stats64.tx.packets')
+	local swp2_tx_bytes_before=$(extract_network_stat "$swp2_stats" \
+				     '.[0].stats64.tx.bytes')
+	local swp1_rx_hi_before=$(ethtool_stats_get ${swp1} "rx_hi")
+	local swp2_tx_hi_before=$(ethtool_stats_get ${swp2} "tx_hi")
+
+	# Assamble the mausezahn command based on the test parameters
+	# For the testis with ipv4 or ipv6, use icmp response packets,
+	# to avoid interaction with the system, to keep packet counters
+	# clean.
+	if [ ${ip_v6} -eq 0 ]; then
+		local ip="-a ${h1_mac} -b ${h2_mac} -A ${H1_IPV4} \
+			  -B ${H2_IPV4} -t icmp unreach,code=1,dscp=${dscp}"
+	else
+		local ip="-6 -a ${h1_mac} -b ${h2_mac} -A ${H1_IPV6} \
+			  -B ${H2_IPV6} -t icmp6 type=1,code=0,dscp=${dscp}"
+	fi
+
+	if [ ${have_vlan} -eq 1 ]; then
+		local vlan_pcp_opt="-Q ${vlan_pcp}:0"
+	else
+		local vlan_pcp_opt=""
+	fi
+	$MZ ${h1} ${ip} -c ${PING_COUNT} -d 10msec ${vlan_pcp_opt}
+
+	# Wait until the switch packet counters are updated
+	sleep 6
+
+	local swp1_stats=$(ip -s -j link show dev ${swp1})
+	local swp2_stats=$(ip -s -j link show dev ${swp2})
+
+	local swp1_rx_packets_after=$(extract_network_stat "$swp1_stats" \
+				      '.[0].stats64.rx.packets')
+	local swp1_rx_bytes_after=$(extract_network_stat "$swp1_stats" \
+				    '.[0].stats64.rx.bytes')
+	local swp2_tx_packets_after=$(extract_network_stat "$swp2_stats" \
+				      '.[0].stats64.tx.packets')
+	local swp2_tx_bytes_after=$(extract_network_stat "$swp2_stats" \
+				    '.[0].stats64.tx.bytes')
+
+	local swp1_rx_packets_diff=$((${swp1_rx_packets_after} - \
+				      ${swp1_rx_packets_before}))
+	local swp2_tx_packets_diff=$((${swp2_tx_packets_after} - \
+				      ${swp2_tx_packets_before}))
+
+	local swp1_rx_hi_after=$(ethtool_stats_get ${swp1} "rx_hi")
+	local swp2_tx_hi_after=$(ethtool_stats_get ${swp2} "tx_hi")
+
+	# Test if any packets were received on swp1, we will rx before and after
+	if [ ${swp1_rx_packets_diff} -lt ${PING_COUNT} ]; then
+		echo "Not expected amount of received packets on ${swp1}"
+		echo "before ${swp1_rx_packets_before} after ${swp1_rx_packets_after}"
+		RET=1
+	fi
+
+	# Test if any packets were transmitted on swp2, we will tx before and after
+	if [ ${swp2_tx_packets_diff} -lt ${PING_COUNT} ]; then
+		echo "Not expected amount of transmitted packets on ${swp2}"
+		echo "before ${swp2_tx_packets_before} after ${swp2_tx_packets_after}"
+		RET=1
+	fi
+
+	# tx/rx_hi counted in bytes. So, we need to compare the difference in bytes
+	local swp1_rx_bytes_diff=$(($swp1_rx_bytes_after - $swp1_rx_bytes_before))
+	local swp2_tx_bytes_diff=$(($swp2_tx_bytes_after - $swp2_tx_bytes_before))
+	local swp1_rx_hi_diff=$(($swp1_rx_hi_after - $swp1_rx_hi_before))
+	local swp2_tx_hi_diff=$(($swp2_tx_hi_after - $swp2_tx_hi_before))
+
+	if [ ${expect_rx_high_prio} -eq 1 ]; then
+		swp1_rx_hi_diff=$((${swp1_rx_hi_diff} - \
+				   ${swp1_rx_packets_diff} * ${ETH_FCS_LEN}))
+		if [ ${swp1_rx_hi_diff} -ne ${swp1_rx_bytes_diff} ]; then
+			echo "Not expected amount of high priority packets received on ${swp1}"
+			echo "RX hi diff: ${swp1_rx_hi_diff}, expected RX bytes diff: ${swp1_rx_bytes_diff}"
+			RET=1
+		fi
+	else
+		if [ ${swp1_rx_hi_diff} -ne 0 ]; then
+			echo "Unexpected amount of high priority packets received on ${swp1}"
+			echo "RX hi diff: ${swp1_rx_hi_diff}, expected 0"
+			RET=1
+		fi
+	fi
+
+	if [ ${expect_tx_high_prio} -eq 1 ]; then
+		swp2_tx_hi_diff=$((${swp2_tx_hi_diff} - \
+				   ${swp2_tx_packets_diff} * ${ETH_FCS_LEN}))
+		if [ ${swp2_tx_hi_diff} -ne ${swp2_tx_bytes_diff} ]; then
+			echo "Not expected amount of high priority packets transmitted on ${swp2}"
+			echo "TX hi diff: ${swp2_tx_hi_diff}, expected TX bytes diff: ${swp2_tx_bytes_diff}"
+			RET=1
+		fi
+	else
+		if [ ${swp2_tx_hi_diff} -ne 0 ]; then
+			echo "Unexpected amount of high priority packets transmitted on ${swp2}"
+			echo "TX hi diff: ${swp2_tx_hi_diff}, expected 0"
+			RET=1
+		fi
+	fi
+
+	log_test "${test_name}"
+}
+
+run_test_dscp()
+{
+	# IPv4 test
+	run_test "$1" "$2" "$3" "$4" "$5" 0 0 0 0
+	# IPv6 test
+	run_test "$1" "$2" "$3" "$4" "$5" 0 0 0 1
+}
+
+run_test_dscp_pcp()
+{
+	# IPv4 test
+	run_test "$1" "$2" "$3" "$4" "$5" 1 "$6" "$7" 0
+	# IPv6 test
+	run_test "$1" "$2" "$3" "$4" "$5" 1 "$6" "$7" 1
+}
+
+port_default_prio_get()
+{
+	local if_name=$1
+	local prio
+
+	prio="$(dcb -j app show dev ${if_name} default-prio | \
+		jq '.default_prio[]')"
+	if [ -z "${prio}" ]; then
+		prio=0
+	fi
+
+	echo ${prio}
+}
+
+test_port_default()
+{
+	local orig_apptrust=$(port_get_default_apptrust ${swp1})
+	local orig_prio=$(port_default_prio_get ${swp1})
+	local apptrust_order=""
+
+	RET=0
+
+	# Make sure no other priority sources will interfere with the test
+	set_apptrust_order ${swp1} "${apptrust_order}"
+
+	for val in $(seq 0 7); do
+		dcb app replace dev ${swp1} default-prio ${val}
+		if [ $val -ne $(port_default_prio_get ${swp1}) ]; then
+			RET=1
+			break
+		fi
+
+		run_test_dscp "Port-default QoS classification, prio: ${val}" \
+			"${apptrust_order}" ${val} 0 0
+	done
+
+	set_apptrust_order ${swp1} "${orig_apptrust}"
+	if [[ "$orig_apptrust" != "$(port_get_default_apptrust ${swp1})" ]]; then
+		RET=1
+	fi
+
+	dcb app replace dev ${swp1} default-prio ${orig_prio}
+	if [ $orig_prio -ne $(port_default_prio_get ${swp1}) ]; then
+		RET=1
+	fi
+
+	log_test "Port-default QoS classification"
+}
+
+port_get_default_apptrust()
+{
+	local if_name=$1
+
+	dcb -j apptrust show dev ${if_name} | jq -r '.order[]' | \
+		tr '\n' ' ' | xargs
+}
+
+test_port_apptrust()
+{
+	local original_dscp_prios_swp1=$(get_dscp_prios ${swp1})
+	local orig_apptrust=$(port_get_default_apptrust ${swp1})
+	local orig_port_prio=$(port_default_prio_get ${swp1})
+	local order_variants=("pcp dscp" "dscp" "pcp")
+	local apptrust_order
+	local port_prio
+	local dscp_prio
+	local pcp_prio
+	local dscp
+	local pcp
+
+	RET=0
+
+	# First, test if apptrust configuration as taken by the kernel
+	for order in "${order_variants[@]}"; do
+		set_apptrust_order ${swp1} "${order}"
+		if [[ "$order" != "$(port_get_default_apptrust ${swp1})" ]]; then
+			RET=1
+			break
+		fi
+	done
+
+	log_test "Apptrust, supported variants"
+
+	# To test if the apptrust configuration is working as expected, we need
+	# to set DSCP priorities for the switch port.
+	init_dscp_prios "${swp1}" "${original_dscp_prios_swp1}"
+
+	# Start with a simple test where all apptrust sources are disabled
+	# default port priority is 0, DSCP priority is mapped to 7.
+	# No high priority packets should be received or transmitted.
+	port_prio=0
+	dscp_prio=7
+	dscp=4
+
+	dcb app replace dev ${swp1} default-prio ${port_prio}
+	dcb app replace dev ${swp1} dscp-prio ${dscp}:${dscp_prio}
+
+	apptrust_order=""
+	set_apptrust_order ${swp1} "${apptrust_order}"
+	# Test with apptrust sources disabled, Packets should get port default
+	# priority which is 0
+	run_test_dscp "Apptrust, all disabled. DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp}
+
+	apptrust_order="pcp"
+	set_apptrust_order ${swp1} "${apptrust_order}"
+	# If PCP is enabled, packets should get PCP priority, which is not
+	# set in this test (no VLAN tags are present in the packet). No high
+	# priority packets should be received or transmitted.
+	run_test_dscp "Apptrust, PCP enabled. DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp}
+
+	apptrust_order="dscp"
+	set_apptrust_order ${swp1} "${apptrust_order}"
+	# If DSCP is enabled, packets should get DSCP priority which is set to 7
+	# in this test. High priority packets should be received and transmitted.
+	run_test_dscp "Apptrust, DSCP enabled. DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp}
+
+	apptrust_order="pcp dscp"
+	set_apptrust_order ${swp1} "${apptrust_order}"
+	# If PCP and DSCP are enabled, PCP would have higher apptrust priority
+	# so packets should get PCP priority. But in this test VLAN PCP is not
+	# set, so it should get DSCP priority which is set to 7. High priority
+	# packets should be received and transmitted.
+	run_test_dscp "Apptrust, PCP and DSCP are enabled. DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp}
+
+	# If VLAN PCP is set, it should have higher apptrust priority than DSCP
+	# so packets should get VLAN PCP priority. Send packets with VLAN PCP
+	# set to 0, DSCP set to 7. Packets should get VLAN PCP priority.
+	# No high priority packets should be transmitted. Due to nature of the
+	# switch, high priority packets will be received.
+	pcp_prio=0
+	pcp=0
+	run_test_dscp_pcp "Apptrust, PCP and DSCP are enabled. PCP ${pcp_prio}, DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp} ${pcp_prio} ${pcp}
+
+	# If VLAN PCP is set to 7, it should have higher apptrust priority than
+	# DSCP so packets should get VLAN PCP priority. Send packets with VLAN
+	# PCP set to 7, DSCP set to 7. Packets should get VLAN PCP priority.
+	# High priority packets should be received and transmitted.
+	pcp_prio=7
+	pcp=7
+	run_test_dscp_pcp "Apptrust, PCP and DSCP are enabled. PCP ${pcp_prio}, DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp} ${pcp_prio} ${pcp}
+	# Now make sure that the switch is able to handle the case where DSCP
+	# priority is set to 0 and PCP priority is set to 7. Packets should get
+	# PCP priority. High priority packets should be received and transmitted.
+	dscp_prio=0
+	dcb app replace dev ${swp1} dscp-prio ${dscp}:${dscp_prio}
+	run_test_dscp_pcp "Apptrust, PCP and DSCP are enabled. PCP ${pcp_prio}, DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp} ${pcp_prio} ${pcp}
+	# If both VLAN PCP and DSCP are set to 0, packets should get 0 priority.
+	# No high priority packets should be received or transmitted.
+	pcp_prio=0
+	pcp=0
+	run_test_dscp_pcp "Apptrust, PCP and DSCP are enabled. PCP ${pcp_prio}, DSCP-prio ${dscp}:${dscp_prio}" \
+		"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp} ${pcp_prio} ${pcp}
+
+	# Restore original priorities
+	if ! restore_priorities "${swp1}" "${original_dscp_prios_swp1}"; then
+		RET=1
+	fi
+
+	set_apptrust_order ${swp1} "${orig_apptrust}"
+	if [ "$orig_apptrust" != "$(port_get_default_apptrust ${swp1})" ]; then
+		RET=1
+	fi
+
+	dcb app replace dev ${swp1} default-prio ${orig_port_prio}
+	if [ $orig_port_prio -ne $(port_default_prio_get ${swp1}) ]; then
+		RET=1
+	fi
+
+	log_test "Apptrust, restore original settings"
+}
+
+# Function to get current DSCP priorities
+get_dscp_prios() {
+	local if_name=$1
+	dcb -j app show dev ${if_name} | jq -c '.dscp_prio'
+}
+
+# Function to set a specific DSCP priority on a device
+replace_dscp_prio() {
+	local if_name=$1
+	local dscp=$2
+	local prio=$3
+	dcb app replace dev ${if_name} dscp-prio ${dscp}:${prio}
+}
+
+# Function to compare DSCP maps
+compare_dscp_maps() {
+	local old_json=$1
+	local new_json=$2
+	local dscp=$3
+	local prio=$4
+
+	# Create a modified old_json with the expected change for comparison
+	local modified_old_json=$(echo "$old_json" |
+		jq --argjson dscp $dscp --argjson prio $prio \
+			'map(if .[0] == $dscp then [$dscp, $prio] else . end)' |
+		tr -d " \n")
+
+	# Compare new_json with the modified_old_json
+	if [[ "$modified_old_json" == "$new_json" ]]; then
+		return 0
+	else
+		return 1
+	fi
+}
+
+# Function to set DSCP priorities
+set_and_verify_dscp() {
+	local port=$1
+	local dscp=$2
+	local new_prio=$3
+
+	local old_prios=$(get_dscp_prios $port)
+
+	replace_dscp_prio "$port" $dscp $new_prio
+
+	# Fetch current settings and compare
+	local current_prios=$(get_dscp_prios $port)
+	if ! compare_dscp_maps "$old_prios" "$current_prios" $dscp $new_prio; then
+		echo "Error: Unintended changes detected in DSCP map for $port after setting DSCP $dscp to $new_prio."
+		return 1
+	fi
+	return 0
+}
+
+# Function to restore original priorities
+restore_priorities() {
+	local port=$1
+	local original_prios=$2
+
+	echo "Removing test artifacts for $port"
+	local current_prios=$(get_dscp_prios $port)
+	local prio_str=$(echo "$current_prios" |
+		jq -r 'map("\(.[0]):\(.[1])") | join(" ")')
+	dcb app del dev $port dscp-prio $prio_str
+
+	echo "Restoring original DSCP priorities for $port"
+	local restore_str=$(echo "$original_prios" |
+		jq -r 'map("\(.[0]):\(.[1])") | join(" ")')
+	dcb app add dev $port dscp-prio $restore_str
+
+	local current_prios=$(get_dscp_prios $port)
+	if [[ "$original_prios" != "$current_prios" ]]; then
+		echo "Error: Failed to restore original DSCP priorities for $port"
+		return 1
+	fi
+	return 0
+}
+
+# Initialize DSCP priorities. Set them to predictable values for testing.
+init_dscp_prios() {
+	local port=$1
+	local original_prios=$2
+
+	echo "Removing any existing DSCP priority mappins for $port"
+	local prio_str=$(echo "$original_prios" |
+		jq -r 'map("\(.[0]):\(.[1])") | join(" ")')
+	dcb app del dev $port dscp-prio $prio_str
+
+	# Initialize DSCP priorities list
+	local dscp_prios=""
+	for dscp in {0..63}; do
+		dscp_prios+=("$dscp:0")
+	done
+
+	echo "Setting initial DSCP priorities map to 0 for $port"
+	dcb app add dev $port dscp-prio ${dscp_prios[@]}
+}
+
+# Main function to test global DSCP map across specified ports
+test_global_dscp_map() {
+	local ports=("$swp1" "$swp2")
+	local original_dscp_prios_port0=$(get_dscp_prios ${ports[0]})
+	local orig_apptrust=$(port_get_default_apptrust ${swp1})
+	local orig_port_prio=$(port_default_prio_get ${swp1})
+	local apptrust_order="dscp"
+	local port_prio=0
+	local dscp_prio
+	local dscp
+
+	RET=0
+
+	set_apptrust_order ${swp1} "${apptrust_order}"
+	dcb app replace dev ${swp1} default-prio ${port_prio}
+
+	# Initialize DSCP priorities
+	init_dscp_prios "${ports[0]}" "$original_dscp_prios_port0"
+
+	# Loop over each DSCP index
+	for dscp in {0..63}; do
+		# and test each Internal Priority value
+		for dscp_prio in {0..7}; do
+			# do it for each port. This is to test if the global DSCP map
+			# is accessible from all ports.
+			for port in "${ports[@]}"; do
+				if ! set_and_verify_dscp "$port" $dscp $dscp_prio; then
+					RET=1
+				fi
+			done
+
+			# Test if the DSCP priority is correctly applied to the packets
+			run_test_dscp "DSCP (${dscp}) QoS classification, prio: ${dscp_prio}" \
+				"${apptrust_order}" ${port_prio} ${dscp_prio} ${dscp}
+			if [ ${RET} -eq 1 ]; then
+				break
+			fi
+		done
+	done
+
+	# Restore original priorities
+	if ! restore_priorities "${ports[0]}" "${original_dscp_prios_port0}"; then
+		RET=1
+	fi
+
+	set_apptrust_order ${swp1} "${orig_apptrust}"
+	if [[ "$orig_apptrust" != "$(port_get_default_apptrust ${swp1})" ]]; then
+		RET=1
+	fi
+
+	dcb app replace dev ${swp1} default-prio ${orig_port_prio}
+	if [ $orig_port_prio -ne $(port_default_prio_get ${swp1}) ]; then
+		RET=1
+	fi
+
+	log_test "DSCP global map"
+}
+
+trap cleanup EXIT
+
+ALL_TESTS="
+	test_port_default
+	test_port_apptrust
+	test_global_dscp_map
+"
+
+setup_prepare
+setup_wait
+tests_run
+
+exit $EXIT_STATUS
-- 
2.39.2