selftests: mlxsw: qos_mc_aware: Add a test for UC awareness

In a previous patch, mlxsw was updated to configure a minimum bandwidth
allowance on MC TCs. Test that this indeed fixes the problem of UC
traffic overload pushing out all MC traffic.

Fixes: b5638d46c90a ("selftests: mlxsw: Add a test for UC behavior under MC flood")
Signed-off-by: Petr Machata <[e-mail]>
Signed-off-by: Ido Schimmel <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

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

···
 # Thus we set MTU to 10K on all involved interfaces. Then both unicast and
 # multicast traffic uses 8K frames.
 #
-# +-----------------------+                +----------------------------------+
-# | H1                    |                |                               H2 |
-# |                       |                |  unicast --> + $h2.111           |
-# |                       |                |  traffic     | 192.0.2.129/28    |
-# |          multicast    |                |              | e-qos-map 0:1     |
-# |          traffic      |                |              |                   |
-# | $h1 + <-----          |                |              + $h2               |
-# +-----|-----------------+                +--------------|-------------------+
-#       |                                                 |
-# +-----|-------------------------------------------------|-------------------+
-# |     + $swp1                                           + $swp2             |
-# |     | >1Gbps                                          | >1Gbps            |
-# | +---|----------------+                     +----------|----------------+  |
-# | |   + $swp1.1        |                     |          + $swp2.111      |  |
+# +---------------------------+            +----------------------------------+
+# | H1                        |            |                               H2 |
+# |                           |            |  unicast --> + $h2.111           |
+# |                 multicast |            |  traffic     | 192.0.2.129/28    |
+# |                 traffic   |            |              | e-qos-map 0:1     |
+# |           $h1 + <-----    |            |              |                   |
+# | 192.0.2.65/28 |           |            |              + $h2               |
+# +---------------|-----------+            +--------------|-------------------+
+#                 |                                       |
+# +---------------|---------------------------------------|-------------------+
+# |         $swp1 +                                       + $swp2             |
+# |        >1Gbps |                                       | >1Gbps            |
+# | +-------------|------+                     +----------|----------------+  |
+# | |     $swp1.1 +      |                     |          + $swp2.111      |  |
 # | |                BR1 |             SW      | BR111                     |  |
-# | |   + $swp3.1        |                     |          + $swp3.111      |  |
-# | +---|----------------+                     +----------|----------------+  |
-# |     \_________________________________________________/                   |
+# | |     $swp3.1 +      |                     |          + $swp3.111      |  |
+# | +-------------|------+                     +----------|----------------+  |
+# |               \_______________________________________/                   |
 # |                                    |                                      |
 # |                                    + $swp3                                |
 # |                                    | 1Gbps bottleneck                     |
···
 #                                      |
 #                                   +--|-----------------+
 #                                   |  + $h3          H3 |
+#                                   |  | 192.0.2.66/28   |
 #                                   |  |                 |
 #                                   |  + $h3.111         |
 #                                   |    192.0.2.130/28  |
···
 ALL_TESTS="
 	ping_ipv4
 	test_mc_aware
+	test_uc_aware
 "
 
 lib_dir=$(dirname $0)/../../../net/forwarding
···
 
 h1_create()
 {
-	simple_if_init $h1
+	simple_if_init $h1 192.0.2.65/28
 	mtu_set $h1 10000
 }
 
 h1_destroy()
 {
 	mtu_restore $h1
-	simple_if_fini $h1
+	simple_if_fini $h1 192.0.2.65/28
 }
 
 h2_create()
···
 
 h3_create()
 {
-	simple_if_init $h3
+	simple_if_init $h3 192.0.2.66/28
 	mtu_set $h3 10000
 
 	vlan_create $h3 111 v$h3 192.0.2.130/28
···
 	vlan_destroy $h3 111
 
 	mtu_restore $h3
-	simple_if_fini $h3
+	simple_if_fini $h3 192.0.2.66/28
 }
 
 switch_create()
···
 	# average ingress rate to somewhat mitigate this.
 	local min_ingress=2147483648
 
-	mausezahn $h2.111 -p 8000 -A 192.0.2.129 -B 192.0.2.130 -c 0 \
+	$MZ $h2.111 -p 8000 -A 192.0.2.129 -B 192.0.2.130 -c 0 \
 		-a own -b $h3mac -t udp -q &
 	sleep 1
 
···
 	check_err $? "Could not get high enough UC-only ingress rate"
 	local ucth1=${uc_rate[1]}
 
-	mausezahn $h1 -p 8000 -c 0 -a own -b bc -t udp -q &
+	$MZ $h1 -p 8000 -c 0 -a own -b bc -t udp -q &
 
 	local d0=$(date +%s)
 	local t0=$(ethtool_stats_get $h3 rx_octets_prio_0)
···
 	echo "    egress UC throughput  $(humanize ${uc_rate_2[1]})"
 	echo "    ingress MC throughput $(humanize $mc_ir)"
 	echo "    egress MC throughput  $(humanize $mc_er)"
+	echo
+}
+
+test_uc_aware()
+{
+	RET=0
+
+	$MZ $h2.111 -p 8000 -A 192.0.2.129 -B 192.0.2.130 -c 0 \
+		-a own -b $h3mac -t udp -q &
+
+	local d0=$(date +%s)
+	local t0=$(ethtool_stats_get $h3 rx_octets_prio_1)
+	local u0=$(ethtool_stats_get $swp2 rx_octets_prio_1)
+	sleep 1
+
+	local attempts=50
+	local passes=0
+	local i
+
+	for ((i = 0; i < attempts; ++i)); do
+		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 0.1; then
+			((passes++))
+		fi
+
+		sleep 0.1
+	done
+
+	local d1=$(date +%s)
+	local t1=$(ethtool_stats_get $h3 rx_octets_prio_1)
+	local u1=$(ethtool_stats_get $swp2 rx_octets_prio_1)
+
+	local interval=$((d1 - d0))
+	local uc_ir=$(rate $u0 $u1 $interval)
+	local uc_er=$(rate $t0 $t1 $interval)
+
+	((attempts == passes))
+	check_err $?
+
+	# Suppress noise from killing mausezahn.
+	{ kill %% && wait; } 2>/dev/null
+
+	log_test "MC performace under UC overload"
+	echo "    ingress UC throughput $(humanize ${uc_ir})"
+	echo "    egress UC throughput  $(humanize ${uc_er})"
+	echo "    sent $attempts BC ARPs, got $passes responses"
 }
 
 trap cleanup EXIT