Merge branch 'mlxsw-PFC-and-headroom-selftests'

Petr Machata says:

====================
mlxsw: PFC and headroom selftests

Recent changes in the headroom management code made it clear that an
automated way of testing this functionality is needed. This patchset brings
two tests: a synthetic headroom behavior test, which verifies mechanics of
headroom management. And a PFC test, which verifies whether this behavior
actually translates into a working lossless configuration.

Both of these tests rely on mlnx_qos[1], a tool that interfaces with Linux
DCB API. The tool was originally written to work with Mellanox NICs, but
does not actually rely on anything Mellanox-specific, and can be used for
mlxsw as well as for any other NIC-like driver. Unlike Open LLDP it does
support buffer commands and permits a fire-and-forget approach to
configuration, which makes it very handy for writing of selftests.

Patches #1-#3 extend the selftest devlink_lib.sh in various ways. Patch #4
then adds a helper wrapper for mlnx_qos to mlxsw's qos_lib.sh.

Patch #5 adds a test for management of port headroom.

Patch #6 adds a PFC test.

[1] https://github.com/Mellanox/mlnx-tools/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/drivers/net/mlxsw/qos_ets_strict.sh

@@ -147,17 +147,26 @@ switch_create()
 
 	# Make sure that ingress quotas are smaller than egress so that there is
 	# room for both streams of traffic to be admitted to shared buffer.
+	devlink_pool_size_thtype_save 0
 	devlink_pool_size_thtype_set 0 dynamic 10000000
+	devlink_pool_size_thtype_save 4
 	devlink_pool_size_thtype_set 4 dynamic 10000000
 
+	devlink_port_pool_th_save $swp1 0
 	devlink_port_pool_th_set $swp1 0 6
+	devlink_tc_bind_pool_th_save $swp1 1 ingress
 	devlink_tc_bind_pool_th_set $swp1 1 ingress 0 6
 
+	devlink_port_pool_th_save $swp2 0
 	devlink_port_pool_th_set $swp2 0 6
+	devlink_tc_bind_pool_th_save $swp2 2 ingress
 	devlink_tc_bind_pool_th_set $swp2 2 ingress 0 6
 
+	devlink_tc_bind_pool_th_save $swp3 1 egress
 	devlink_tc_bind_pool_th_set $swp3 1 egress 4 7
+	devlink_tc_bind_pool_th_save $swp3 2 egress
 	devlink_tc_bind_pool_th_set $swp3 2 egress 4 7
+	devlink_port_pool_th_save $swp3 4
 	devlink_port_pool_th_set $swp3 4 7
 }
 

tools/testing/selftests/drivers/net/mlxsw/qos_headroom.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ALL_TESTS="
+	test_defaults
+	test_dcb_ets
+	test_mtu
+	test_pfc
+	test_int_buf
+	test_tc_priomap
+	test_tc_mtu
+	test_tc_sizes
+	test_tc_int_buf
+"
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+NUM_NETIFS=0
+source $lib_dir/lib.sh
+source $lib_dir/devlink_lib.sh
+source qos_lib.sh
+
+swp=$NETIF_NO_CABLE
+
+cleanup()
+{
+	pre_cleanup
+}
+
+get_prio_pg()
+{
+	__mlnx_qos -i $swp | sed -n '/^PFC/,/^[^[:space:]]/p' |
+		grep buffer | sed 's/ \+/ /g' | cut -d' ' -f 2-
+}
+
+get_prio_pfc()
+{
+	__mlnx_qos -i $swp | sed -n '/^PFC/,/^[^[:space:]]/p' |
+		grep enabled | sed 's/ \+/ /g' | cut -d' ' -f 2-
+}
+
+get_prio_tc()
+{
+	__mlnx_qos -i $swp | sed -n '/^tc/,$p' |
+		awk '/^tc/ { TC = $2 }
+		     /priority:/ { PRIO[$2]=TC }
+		     END {
+			for (i in PRIO)
+			    printf("%d ", PRIO[i])
+		     }'
+}
+
+get_buf_size()
+{
+	local idx=$1; shift
+
+	__mlnx_qos -i $swp | grep Receive | sed 's/.*: //' | cut -d, -f $((idx + 1))
+}
+
+get_tot_size()
+{
+	__mlnx_qos -i $swp | grep Receive | sed 's/.*total_size=//'
+}
+
+check_prio_pg()
+{
+	local expect=$1; shift
+
+	local current=$(get_prio_pg)
+	test "$current" = "$expect"
+	check_err $? "prio2buffer is '$current', expected '$expect'"
+}
+
+check_prio_pfc()
+{
+	local expect=$1; shift
+
+	local current=$(get_prio_pfc)
+	test "$current" = "$expect"
+	check_err $? "prio PFC is '$current', expected '$expect'"
+}
+
+check_prio_tc()
+{
+	local expect=$1; shift
+
+	local current=$(get_prio_tc)
+	test "$current" = "$expect"
+	check_err $? "prio_tc is '$current', expected '$expect'"
+}
+
+__check_buf_size()
+{
+	local idx=$1; shift
+	local expr=$1; shift
+	local what=$1; shift
+
+	local current=$(get_buf_size $idx)
+	((current $expr))
+	check_err $? "${what}buffer $idx size is '$current', expected '$expr'"
+	echo $current
+}
+
+check_buf_size()
+{
+	__check_buf_size "$@" > /dev/null
+}
+
+test_defaults()
+{
+	RET=0
+
+	check_prio_pg "0 0 0 0 0 0 0 0 "
+	check_prio_tc "0 0 0 0 0 0 0 0 "
+	check_prio_pfc "0 0 0 0 0 0 0 0 "
+
+	log_test "Default headroom configuration"
+}
+
+test_dcb_ets()
+{
+	RET=0
+
+	__mlnx_qos -i $swp --prio_tc=0,2,4,6,1,3,5,7 > /dev/null
+
+	check_prio_pg "0 2 4 6 1 3 5 7 "
+	check_prio_tc "0 2 4 6 1 3 5 7 "
+	check_prio_pfc "0 0 0 0 0 0 0 0 "
+
+	__mlnx_qos -i $swp --prio_tc=0,0,0,0,0,0,0,0 > /dev/null
+
+	check_prio_pg "0 0 0 0 0 0 0 0 "
+	check_prio_tc "0 0 0 0 0 0 0 0 "
+
+	__mlnx_qos -i $swp --prio2buffer=1,3,5,7,0,2,4,6 &> /dev/null
+	check_fail $? "prio2buffer accepted in DCB mode"
+
+	log_test "Configuring headroom through ETS"
+}
+
+test_mtu()
+{
+	local what=$1; shift
+	local buf0size_2
+	local buf0size
+
+	RET=0
+	buf0size=$(__check_buf_size 0 "> 0")
+
+	mtu_set $swp 3000
+	buf0size_2=$(__check_buf_size 0 "> $buf0size" "MTU 3000: ")
+	mtu_restore $swp
+
+	mtu_set $swp 6000
+	check_buf_size 0 "> $buf0size_2" "MTU 6000: "
+	mtu_restore $swp
+
+	check_buf_size 0 "== $buf0size"
+
+	log_test "${what}MTU impacts buffer size"
+}
+
+test_tc_mtu()
+{
+	# In TC mode, MTU still impacts the threshold below which a buffer is
+	# not permitted to go.
+
+	tc qdisc replace dev $swp root handle 1: bfifo limit 1.5M
+	test_mtu "TC: "
+	tc qdisc delete dev $swp root
+}
+
+test_pfc()
+{
+	RET=0
+
+	__mlnx_qos -i $swp --prio_tc=0,0,0,0,0,1,2,3 > /dev/null
+
+	local buf0size=$(get_buf_size 0)
+	local buf1size=$(get_buf_size 1)
+	local buf2size=$(get_buf_size 2)
+	local buf3size=$(get_buf_size 3)
+	check_buf_size 0 "> 0"
+	check_buf_size 1 "> 0"
+	check_buf_size 2 "> 0"
+	check_buf_size 3 "> 0"
+	check_buf_size 4 "== 0"
+	check_buf_size 5 "== 0"
+	check_buf_size 6 "== 0"
+	check_buf_size 7 "== 0"
+
+	log_test "Buffer size sans PFC"
+
+	RET=0
+
+	__mlnx_qos -i $swp --pfc=0,0,0,0,0,1,1,1 --cable_len=0 > /dev/null
+
+	check_prio_pg "0 0 0 0 0 1 2 3 "
+	check_prio_pfc "0 0 0 0 0 1 1 1 "
+	check_buf_size 0 "== $buf0size"
+	check_buf_size 1 "> $buf1size"
+	check_buf_size 2 "> $buf2size"
+	check_buf_size 3 "> $buf3size"
+
+	local buf1size=$(get_buf_size 1)
+	check_buf_size 2 "== $buf1size"
+	check_buf_size 3 "== $buf1size"
+
+	log_test "PFC: Cable length 0"
+
+	RET=0
+
+	__mlnx_qos -i $swp --pfc=0,0,0,0,0,1,1,1 --cable_len=1000 > /dev/null
+
+	check_buf_size 0 "== $buf0size"
+	check_buf_size 1 "> $buf1size"
+	check_buf_size 2 "> $buf1size"
+	check_buf_size 3 "> $buf1size"
+
+	log_test "PFC: Cable length 1000"
+
+	RET=0
+
+	__mlnx_qos -i $swp --pfc=0,0,0,0,0,0,0,0 --cable_len=0 > /dev/null
+	__mlnx_qos -i $swp --prio_tc=0,0,0,0,0,0,0,0 > /dev/null
+
+	check_prio_pg "0 0 0 0 0 0 0 0 "
+	check_prio_tc "0 0 0 0 0 0 0 0 "
+	check_buf_size 0 "> 0"
+	check_buf_size 1 "== 0"
+	check_buf_size 2 "== 0"
+	check_buf_size 3 "== 0"
+	check_buf_size 4 "== 0"
+	check_buf_size 5 "== 0"
+	check_buf_size 6 "== 0"
+	check_buf_size 7 "== 0"
+
+	log_test "PFC: Restore defaults"
+}
+
+test_tc_priomap()
+{
+	RET=0
+
+	__mlnx_qos -i $swp --prio_tc=0,1,2,3,4,5,6,7 > /dev/null
+	check_prio_pg "0 1 2 3 4 5 6 7 "
+
+	tc qdisc replace dev $swp root handle 1: bfifo limit 1.5M
+	check_prio_pg "0 0 0 0 0 0 0 0 "
+
+	__mlnx_qos -i $swp --prio2buffer=1,3,5,7,0,2,4,6 > /dev/null
+	check_prio_pg "1 3 5 7 0 2 4 6 "
+
+	tc qdisc delete dev $swp root
+	check_prio_pg "0 1 2 3 4 5 6 7 "
+
+	# Clean up.
+	tc qdisc replace dev $swp root handle 1: bfifo limit 1.5M
+	__mlnx_qos -i $swp --prio2buffer=0,0,0,0,0,0,0,0 > /dev/null
+	tc qdisc delete dev $swp root
+	__mlnx_qos -i $swp --prio_tc=0,0,0,0,0,0,0,0 > /dev/null
+
+	log_test "TC: priomap"
+}
+
+test_tc_sizes()
+{
+	local cell_size=$(devlink_cell_size_get)
+	local size=$((cell_size * 1000))
+
+	RET=0
+
+	__mlnx_qos -i $swp --buffer_size=$size,0,0,0,0,0,0,0 &> /dev/null
+	check_fail $? "buffer_size should fail before qdisc is added"
+
+	tc qdisc replace dev $swp root handle 1: bfifo limit 1.5M
+
+	__mlnx_qos -i $swp --buffer_size=$size,0,0,0,0,0,0,0 > /dev/null
+	check_err $? "buffer_size should pass after qdisc is added"
+	check_buf_size 0 "== $size" "set size: "
+
+	mtu_set $swp 6000
+	check_buf_size 0 "== $size" "set MTU: "
+	mtu_restore $swp
+
+	__mlnx_qos -i $swp --buffer_size=0,0,0,0,0,0,0,0 > /dev/null
+
+	# After replacing the qdisc for the same kind, buffer_size still has to
+	# work.
+	tc qdisc replace dev $swp root handle 1: bfifo limit 1M
+
+	__mlnx_qos -i $swp --buffer_size=$size,0,0,0,0,0,0,0 > /dev/null
+	check_buf_size 0 "== $size" "post replace, set size: "
+
+	__mlnx_qos -i $swp --buffer_size=0,0,0,0,0,0,0,0 > /dev/null
+
+	# Likewise after replacing for a different kind.
+	tc qdisc replace dev $swp root handle 2: prio bands 8
+
+	__mlnx_qos -i $swp --buffer_size=$size,0,0,0,0,0,0,0 > /dev/null
+	check_buf_size 0 "== $size" "post replace different kind, set size: "
+
+	tc qdisc delete dev $swp root
+
+	__mlnx_qos -i $swp --buffer_size=$size,0,0,0,0,0,0,0 &> /dev/null
+	check_fail $? "buffer_size should fail after qdisc is deleted"
+
+	log_test "TC: buffer size"
+}
+
+test_int_buf()
+{
+	local what=$1; shift
+
+	RET=0
+
+	local buf0size=$(get_buf_size 0)
+	local tot_size=$(get_tot_size)
+
+	# Size of internal buffer and buffer 9.
+	local dsize=$((tot_size - buf0size))
+
+	tc qdisc add dev $swp clsact
+	tc filter add dev $swp egress matchall skip_sw action mirred egress mirror dev $swp
+
+	local buf0size_2=$(get_buf_size 0)
+	local tot_size_2=$(get_tot_size)
+	local dsize_2=$((tot_size_2 - buf0size_2))
+
+	# Egress SPAN should have added to the "invisible" buffer configuration.
+	((dsize_2 > dsize))
+	check_err $? "Invisible buffers account for '$dsize_2', expected '> $dsize'"
+
+	mtu_set $swp 3000
+
+	local buf0size_3=$(get_buf_size 0)
+	local tot_size_3=$(get_tot_size)
+	local dsize_3=$((tot_size_3 - buf0size_3))
+
+	# MTU change might change buffer 0, which will show at total, but the
+	# hidden buffers should stay the same size.
+	((dsize_3 == dsize_2))
+	check_err $? "MTU change: Invisible buffers account for '$dsize_3', expected '== $dsize_2'"
+
+	mtu_restore $swp
+	tc qdisc del dev $swp clsact
+
+	# After SPAN removal, hidden buffers should be back to the original sizes.
+	local buf0size_4=$(get_buf_size 0)
+	local tot_size_4=$(get_tot_size)
+	local dsize_4=$((tot_size_4 - buf0size_4))
+	((dsize_4 == dsize))
+	check_err $? "SPAN removed: Invisible buffers account for '$dsize_4', expected '== $dsize'"
+
+	log_test "${what}internal buffer size"
+}
+
+test_tc_int_buf()
+{
+	local cell_size=$(devlink_cell_size_get)
+	local size=$((cell_size * 1000))
+
+	tc qdisc replace dev $swp root handle 1: bfifo limit 1.5M
+	test_int_buf "TC: "
+
+	__mlnx_qos -i $swp --buffer_size=$size,0,0,0,0,0,0,0 > /dev/null
+	test_int_buf "TC+buffsize: "
+
+	__mlnx_qos -i $swp --buffer_size=0,0,0,0,0,0,0,0 > /dev/null
+	tc qdisc delete dev $swp root
+}
+
+trap cleanup EXIT
+
+bail_on_lldpad
+setup_wait
+tests_run
+
+exit $EXIT_STATUS

tools/testing/selftests/drivers/net/mlxsw/qos_lib.sh

@@ -82,3 +82,17 @@ bail_on_lldpad()
 		fi
 	fi
 }
+
+__mlnx_qos()
+{
+	local err
+
+	mlnx_qos "$@" 2>/dev/null
+	err=$?
+
+	if ((err)); then
+		echo "Error ($err) in mlnx_qos $@" >/dev/stderr
+	fi
+
+	return $err
+}

tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh

@@ -145,12 +145,17 @@ switch_create()
 
 	# Make sure that ingress quotas are smaller than egress so that there is
 	# room for both streams of traffic to be admitted to shared buffer.
+	devlink_port_pool_th_save $swp1 0
 	devlink_port_pool_th_set $swp1 0 5
+	devlink_tc_bind_pool_th_save $swp1 0 ingress
 	devlink_tc_bind_pool_th_set $swp1 0 ingress 0 5
 
+	devlink_port_pool_th_save $swp2 0
 	devlink_port_pool_th_set $swp2 0 5
+	devlink_tc_bind_pool_th_save $swp2 1 ingress
 	devlink_tc_bind_pool_th_set $swp2 1 ingress 0 5
 
+	devlink_port_pool_th_save $swp3 4
 	devlink_port_pool_th_set $swp3 4 12
 }
 

tools/testing/selftests/drivers/net/mlxsw/sch_ets.sh

@@ -27,11 +27,17 @@ switch_create()
 	# amount of traffic that is admitted to the shared buffers. This makes
 	# sure that there is always enough traffic of all types to select from
 	# for the DWRR process.
+	devlink_port_pool_th_save $swp1 0
 	devlink_port_pool_th_set $swp1 0 12
+	devlink_tc_bind_pool_th_save $swp1 0 ingress
 	devlink_tc_bind_pool_th_set $swp1 0 ingress 0 12
+	devlink_port_pool_th_save $swp2 4
 	devlink_port_pool_th_set $swp2 4 12
+	devlink_tc_bind_pool_th_save $swp2 7 egress
 	devlink_tc_bind_pool_th_set $swp2 7 egress 4 5
+	devlink_tc_bind_pool_th_save $swp2 6 egress
 	devlink_tc_bind_pool_th_set $swp2 6 egress 4 5
+	devlink_tc_bind_pool_th_save $swp2 5 egress
 	devlink_tc_bind_pool_th_set $swp2 5 egress 4 5
 
 	# Note: sch_ets_core.sh uses VLAN ingress-qos-map to assign packet

tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh

@@ -208,6 +208,7 @@ switch_create()
 	ip link set dev br2_11 up
 
 	local size=$(devlink_pool_size_thtype 0 | cut -d' ' -f 1)
+	devlink_port_pool_th_save $swp3 8
 	devlink_port_pool_th_set $swp3 8 $size
 }
 

tools/testing/selftests/net/forwarding/devlink_lib.sh

@@ -5,7 +5,7 @@
 # Defines
 
 if [[ ! -v DEVLINK_DEV ]]; then
-	DEVLINK_DEV=$(devlink port show "${NETIFS[p1]}" -j \
+	DEVLINK_DEV=$(devlink port show "${NETIFS[p1]:-$NETIF_NO_CABLE}" -j \
 			     | jq -r '.port | keys[]' | cut -d/ -f-2)
 	if [ -z "$DEVLINK_DEV" ]; then
 		echo "SKIP: ${NETIFS[p1]} has no devlink device registered for it"
@@ -117,6 +117,12 @@ devlink_reload()
 
 declare -A DEVLINK_ORIG
 
+# Changing pool type from static to dynamic causes reinterpretation of threshold
+# values. They therefore need to be saved before pool type is changed, then the
+# pool type can be changed, and then the new values need to be set up. Therefore
+# instead of saving the current state implicitly in the _set call, provide
+# functions for all three primitives: save, set, and restore.
+
 devlink_port_pool_threshold()
 {
 	local port=$1; shift
@@ -126,14 +132,21 @@ devlink_port_pool_threshold()
 		| jq '.port_pool."'"$port"'"[].threshold'
 }
 
-devlink_port_pool_th_set()
+devlink_port_pool_th_save()
 {
 	local port=$1; shift
 	local pool=$1; shift
-	local th=$1; shift
 	local key="port_pool($port,$pool).threshold"
 
 	DEVLINK_ORIG[$key]=$(devlink_port_pool_threshold $port $pool)
+}
+
+devlink_port_pool_th_set()
+{
+	local port=$1; shift
+	local pool=$1; shift
+	local th=$1; shift
+
 	devlink sb port pool set $port pool $pool th $th
 }
 
@@ -142,8 +155,13 @@ devlink_port_pool_th_restore()
 	local port=$1; shift
 	local pool=$1; shift
 	local key="port_pool($port,$pool).threshold"
+	local -a orig=(${DEVLINK_ORIG[$key]})
 
-	devlink sb port pool set $port pool $pool th ${DEVLINK_ORIG[$key]}
+	if [[ -z $orig ]]; then
+		echo "WARNING: Mismatched devlink_port_pool_th_restore"
+	else
+		devlink sb port pool set $port pool $pool th $orig
+	fi
 }
 
 devlink_pool_size_thtype()
@@ -154,14 +172,20 @@ devlink_pool_size_thtype()
 	    | jq -r '.pool[][] | (.size, .thtype)'
 }
 
+devlink_pool_size_thtype_save()
+{
+	local pool=$1; shift
+	local key="pool($pool).size_thtype"
+
+	DEVLINK_ORIG[$key]=$(devlink_pool_size_thtype $pool)
+}
+
 devlink_pool_size_thtype_set()
 {
 	local pool=$1; shift
 	local thtype=$1; shift
 	local size=$1; shift
-	local key="pool($pool).size_thtype"
 
-	DEVLINK_ORIG[$key]=$(devlink_pool_size_thtype $pool)
 	devlink sb pool set "$DEVLINK_DEV" pool $pool size $size thtype $thtype
 }
 
@@ -171,8 +195,12 @@ devlink_pool_size_thtype_restore()
 	local key="pool($pool).size_thtype"
 	local -a orig=(${DEVLINK_ORIG[$key]})
 
-	devlink sb pool set "$DEVLINK_DEV" pool $pool \
-		size ${orig[0]} thtype ${orig[1]}
+	if [[ -z ${orig[0]} ]]; then
+		echo "WARNING: Mismatched devlink_pool_size_thtype_restore"
+	else
+		devlink sb pool set "$DEVLINK_DEV" pool $pool \
+			size ${orig[0]} thtype ${orig[1]}
+	fi
 }
 
 devlink_tc_bind_pool_th()
@@ -185,6 +213,16 @@ devlink_tc_bind_pool_th()
 	    | jq -r '.tc_bind[][] | (.pool, .threshold)'
 }
 
+devlink_tc_bind_pool_th_save()
+{
+	local port=$1; shift
+	local tc=$1; shift
+	local dir=$1; shift
+	local key="tc_bind($port,$dir,$tc).pool_th"
+
+	DEVLINK_ORIG[$key]=$(devlink_tc_bind_pool_th $port $tc $dir)
+}
+
 devlink_tc_bind_pool_th_set()
 {
 	local port=$1; shift
@@ -192,9 +230,7 @@ devlink_tc_bind_pool_th_set()
 	local dir=$1; shift
 	local pool=$1; shift
 	local th=$1; shift
-	local key="tc_bind($port,$dir,$tc).pool_th"
 
-	DEVLINK_ORIG[$key]=$(devlink_tc_bind_pool_th $port $tc $dir)
 	devlink sb tc bind set $port tc $tc type $dir pool $pool th $th
 }
 
@@ -206,8 +242,12 @@ devlink_tc_bind_pool_th_restore()
 	local key="tc_bind($port,$dir,$tc).pool_th"
 	local -a orig=(${DEVLINK_ORIG[$key]})
 
-	devlink sb tc bind set $port tc $tc type $dir \
-		pool ${orig[0]} th ${orig[1]}
+	if [[ -z ${orig[0]} ]]; then
+		echo "WARNING: Mismatched devlink_tc_bind_pool_th_restore"
+	else
+		devlink sb tc bind set $port tc $tc type $dir \
+			pool ${orig[0]} th ${orig[1]}
+	fi
 }
 
 devlink_traps_num_get()
@@ -509,3 +549,9 @@ devlink_cpu_port_get()
 
 	echo "$DEVLINK_DEV/$cpu_dl_port_num"
 }
+
+devlink_cell_size_get()
+{
+	devlink sb pool show "$DEVLINK_DEV" pool 0 -j \
+	    | jq '.pool[][].cell_size'
+}