xref: /linux/tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh (revision 8a5f956a9fb7d74fff681145082acfad5afa6bb8) 
1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3#
4# A test for switch behavior under MC overload. An issue in Spectrum chips
5# causes throughput of UC traffic to drop severely when a switch is under heavy
6# MC load. This issue can be overcome by putting the switch to MC-aware mode.
7# This test verifies that UC performance stays intact even as the switch is
8# under MC flood, and therefore that the MC-aware mode is enabled and correctly
9# configured.
10#
11# Because mlxsw throttles CPU port, the traffic can't actually reach userspace
12# at full speed. That makes it impossible to use iperf3 to simply measure the
13# throughput, because many packets (that reach $h3) don't get to the kernel at
14# all even in UDP mode (the situation is even worse in TCP mode, where one can't
15# hope to see more than a couple Mbps).
16#
17# So instead we send traffic with mausezahn and use RX ethtool counters at $h3.
18# Multicast traffic is untagged, unicast traffic is tagged with PCP 1. Therefore
19# each gets a different priority and we can use per-prio ethtool counters to
20# measure the throughput. In order to avoid prioritizing unicast traffic, prio
21# qdisc is installed on $swp3 and maps all priorities to the same band #7 (and
22# thus TC 0).
23#
24# Mausezahn can't actually saturate the links unless it's using large frames.
25# Thus we set MTU to 10K on all involved interfaces. Then both unicast and
26# multicast traffic uses 8K frames.
27#
28# +---------------------------+            +----------------------------------+
29# | H1                        |            |                               H2 |
30# |                           |            |  unicast --> + $h2.111           |
31# |                 multicast |            |  traffic     | 192.0.2.129/28    |
32# |                 traffic   |            |              | e-qos-map 0:1     |
33# |           $h1 + <-----    |            |              |                   |
34# | 192.0.2.65/28 |           |            |              + $h2               |
35# +---------------|-----------+            +--------------|-------------------+
36#                 |                                       |
37# +---------------|---------------------------------------|-------------------+
38# |         $swp1 +                                       + $swp2             |
39# |        >1Gbps |                                       | >1Gbps            |
40# | +-------------|------+                     +----------|----------------+  |
41# | |     $swp1.1 +      |                     |          + $swp2.111      |  |
42# | |                BR1 |             SW      | BR111                     |  |
43# | |     $swp3.1 +      |                     |          + $swp3.111      |  |
44# | +-------------|------+                     +----------|----------------+  |
45# |               \_______________________________________/                   |
46# |                                    |                                      |
47# |                                    + $swp3                                |
48# |                                    | 1Gbps bottleneck                     |
49# |                                    | prio qdisc: {0..7} -> 7              |
50# +------------------------------------|--------------------------------------+
51#                                      |
52#                                   +--|-----------------+
53#                                   |  + $h3          H3 |
54#                                   |  | 192.0.2.66/28   |
55#                                   |  |                 |
56#                                   |  + $h3.111         |
57#                                   |    192.0.2.130/28  |
58#                                   +--------------------+
59
60ALL_TESTS="
61	ping_ipv4
62	test_mc_aware
63	test_uc_aware
64"
65
66lib_dir=$(dirname $0)/../../../net/forwarding
67
68NUM_NETIFS=6
69source $lib_dir/lib.sh
70source $lib_dir/devlink_lib.sh
71source qos_lib.sh
72
73h1_create()
74{
75	adf_simple_if_init $h1 192.0.2.65/28
76
77	mtu_set $h1 10000
78	defer mtu_restore $h1
79}
80
81h2_create()
82{
83	adf_simple_if_init $h2
84
85	mtu_set $h2 10000
86	defer mtu_restore $h2
87
88	vlan_create $h2 111 v$h2 192.0.2.129/28
89	defer vlan_destroy $h2 111
90	ip link set dev $h2.111 type vlan egress-qos-map 0:1
91}
92
93h3_create()
94{
95	adf_simple_if_init $h3 192.0.2.66/28
96
97	mtu_set $h3 10000
98	defer mtu_restore $h3
99
100	vlan_create $h3 111 v$h3 192.0.2.130/28
101	defer vlan_destroy $h3 111
102}
103
104switch_create()
105{
106	ip link set dev $swp1 up
107	defer ip link set dev $swp1 down
108
109	mtu_set $swp1 10000
110	defer mtu_restore $swp1
111
112	ip link set dev $swp2 up
113	defer ip link set dev $swp2 down
114
115	mtu_set $swp2 10000
116	defer mtu_restore $swp2
117
118	ip link set dev $swp3 up
119	defer ip link set dev $swp3 down
120
121	mtu_set $swp3 10000
122	defer mtu_restore $swp3
123
124	vlan_create $swp2 111
125	defer vlan_destroy $swp2 111
126
127	vlan_create $swp3 111
128	defer vlan_destroy $swp3 111
129
130	tc qdisc replace dev $swp3 root handle 3: tbf rate 1gbit \
131		burst 128K limit 1G
132	defer tc qdisc del dev $swp3 root handle 3:
133
134	tc qdisc replace dev $swp3 parent 3:3 handle 33: \
135		prio bands 8 priomap 7 7 7 7 7 7 7 7
136	defer tc qdisc del dev $swp3 parent 3:3 handle 33:
137
138	ip link add name br1 type bridge vlan_filtering 0
139	defer ip link del dev br1
140	ip link set dev br1 addrgenmode none
141	ip link set dev br1 up
142
143	ip link set dev $swp1 master br1
144	defer ip link set dev $swp1 nomaster
145
146	ip link set dev $swp3 master br1
147	defer ip link set dev $swp3 nomaster
148
149	ip link add name br111 type bridge vlan_filtering 0
150	defer ip link del dev br111
151	ip link set dev br111 addrgenmode none
152	ip link set dev br111 up
153
154	ip link set dev $swp2.111 master br111
155	defer ip link set dev $swp2.111 nomaster
156
157	ip link set dev $swp3.111 master br111
158	defer ip link set dev $swp3.111 nomaster
159
160	# Make sure that ingress quotas are smaller than egress so that there is
161	# room for both streams of traffic to be admitted to shared buffer.
162	devlink_port_pool_th_save $swp1 0
163	devlink_port_pool_th_set $swp1 0 5
164	defer devlink_port_pool_th_restore $swp1 0
165
166	devlink_tc_bind_pool_th_save $swp1 0 ingress
167	devlink_tc_bind_pool_th_set $swp1 0 ingress 0 5
168	defer devlink_tc_bind_pool_th_restore $swp1 0 ingress
169
170	devlink_port_pool_th_save $swp2 0
171	devlink_port_pool_th_set $swp2 0 5
172	defer devlink_port_pool_th_restore $swp2 0
173
174	devlink_tc_bind_pool_th_save $swp2 1 ingress
175	devlink_tc_bind_pool_th_set $swp2 1 ingress 0 5
176	defer devlink_tc_bind_pool_th_restore $swp2 1 ingress
177
178	devlink_port_pool_th_save $swp3 4
179	devlink_port_pool_th_set $swp3 4 12
180	defer devlink_port_pool_th_restore $swp3 4
181}
182
183setup_prepare()
184{
185	h1=${NETIFS[p1]}
186	swp1=${NETIFS[p2]}
187
188	swp2=${NETIFS[p3]}
189	h2=${NETIFS[p4]}
190
191	swp3=${NETIFS[p5]}
192	h3=${NETIFS[p6]}
193
194	h3mac=$(mac_get $h3)
195
196	adf_vrf_prepare
197
198	h1_create
199	h2_create
200	h3_create
201	switch_create
202}
203
204ping_ipv4()
205{
206	ping_test $h2 192.0.2.130
207}
208
209__run_uc_measure_rate()
210{
211	local what=$1; shift
212	local -a uc_rate
213
214	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
215	defer stop_traffic $!
216
217	uc_rate=($(measure_rate $swp2 $h3 rx_octets_prio_1 "$what"))
218	check_err $? "Could not get high enough $what ingress rate"
219
220	echo ${uc_rate[@]}
221}
222
223run_uc_measure_rate()
224{
225	in_defer_scope __run_uc_measure_rate "$@"
226}
227
228test_mc_aware()
229{
230	RET=0
231
232	local -a uc_rate=($(run_uc_measure_rate "UC-only"))
233	local ucth1=${uc_rate[1]}
234
235	start_traffic $h1 192.0.2.65 bc bc
236	defer stop_traffic $!
237
238	local d0=$(date +%s)
239	local t0=$(ethtool_stats_get $h3 rx_octets_prio_0)
240	local u0=$(ethtool_stats_get $swp1 rx_octets_prio_0)
241
242	local -a uc_rate_2=($(run_uc_measure_rate "UC+MC"))
243	local ucth2=${uc_rate_2[1]}
244
245	local d1=$(date +%s)
246	local t1=$(ethtool_stats_get $h3 rx_octets_prio_0)
247	local u1=$(ethtool_stats_get $swp1 rx_octets_prio_0)
248
249	local deg=$(bc <<< "
250			scale=2
251			ret = 100 * ($ucth1 - $ucth2) / $ucth1
252			if (ret > 0) { ret } else { 0 }
253		    ")
254
255	# Minimum shaper of 200Mbps on MC TCs should cause about 20% of
256	# degradation on 1Gbps link.
257	check_err $(bc <<< "$deg < 15") "Minimum shaper not in effect"
258	check_err $(bc <<< "$deg > 25") "MC traffic degrades UC performance too much"
259
260	local interval=$((d1 - d0))
261	local mc_ir=$(rate $u0 $u1 $interval)
262	local mc_er=$(rate $t0 $t1 $interval)
263
264	log_test "UC performance under MC overload"
265
266	echo "UC-only throughput  $(humanize $ucth1)"
267	echo "UC+MC throughput    $(humanize $ucth2)"
268	echo "Degradation         $deg %"
269	echo
270	echo "Full report:"
271	echo "  UC only:"
272	echo "    ingress UC throughput $(humanize ${uc_rate[0]})"
273	echo "    egress UC throughput  $(humanize ${uc_rate[1]})"
274	echo "  UC+MC:"
275	echo "    ingress UC throughput $(humanize ${uc_rate_2[0]})"
276	echo "    egress UC throughput  $(humanize ${uc_rate_2[1]})"
277	echo "    ingress MC throughput $(humanize $mc_ir)"
278	echo "    egress MC throughput  $(humanize $mc_er)"
279	echo
280}
281
282test_uc_aware()
283{
284	RET=0
285
286	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
287	defer stop_traffic $!
288
289	local d0=$(date +%s)
290	local t0=$(ethtool_stats_get $h3 rx_octets_prio_1)
291	local u0=$(ethtool_stats_get $swp2 rx_octets_prio_1)
292	sleep 1
293
294	local attempts=50
295	local passes=0
296	local i
297
298	for ((i = 0; i < attempts; ++i)); do
299		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 1; then
300			((passes++))
301		fi
302
303		sleep 0.1
304	done
305
306	local d1=$(date +%s)
307	local t1=$(ethtool_stats_get $h3 rx_octets_prio_1)
308	local u1=$(ethtool_stats_get $swp2 rx_octets_prio_1)
309
310	local interval=$((d1 - d0))
311	local uc_ir=$(rate $u0 $u1 $interval)
312	local uc_er=$(rate $t0 $t1 $interval)
313
314	((attempts == passes))
315	check_err $?
316
317	log_test "MC performance under UC overload"
318	echo "    ingress UC throughput $(humanize ${uc_ir})"
319	echo "    egress UC throughput  $(humanize ${uc_er})"
320	echo "    sent $attempts BC ARPs, got $passes responses"
321}
322
323trap cleanup EXIT
324
325setup_prepare
326setup_wait
327
328tests_run
329
330exit $EXIT_STATUS
331