xref: /linux/tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0) 
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	simple_if_init $h1 192.0.2.65/28
76	mtu_set $h1 10000
77}
78
79h1_destroy()
80{
81	mtu_restore $h1
82	simple_if_fini $h1 192.0.2.65/28
83}
84
85h2_create()
86{
87	simple_if_init $h2
88	mtu_set $h2 10000
89
90	vlan_create $h2 111 v$h2 192.0.2.129/28
91	ip link set dev $h2.111 type vlan egress-qos-map 0:1
92}
93
94h2_destroy()
95{
96	vlan_destroy $h2 111
97
98	mtu_restore $h2
99	simple_if_fini $h2
100}
101
102h3_create()
103{
104	simple_if_init $h3 192.0.2.66/28
105	mtu_set $h3 10000
106
107	vlan_create $h3 111 v$h3 192.0.2.130/28
108}
109
110h3_destroy()
111{
112	vlan_destroy $h3 111
113
114	mtu_restore $h3
115	simple_if_fini $h3 192.0.2.66/28
116}
117
118switch_create()
119{
120	ip link set dev $swp1 up
121	mtu_set $swp1 10000
122
123	ip link set dev $swp2 up
124	mtu_set $swp2 10000
125
126	ip link set dev $swp3 up
127	mtu_set $swp3 10000
128
129	vlan_create $swp2 111
130	vlan_create $swp3 111
131
132	tc qdisc replace dev $swp3 root handle 3: tbf rate 1gbit \
133		burst 128K limit 1G
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
137	ip link add name br1 type bridge vlan_filtering 0
138	ip link set dev br1 addrgenmode none
139	ip link set dev br1 up
140	ip link set dev $swp1 master br1
141	ip link set dev $swp3 master br1
142
143	ip link add name br111 type bridge vlan_filtering 0
144	ip link set dev br111 addrgenmode none
145	ip link set dev br111 up
146	ip link set dev $swp2.111 master br111
147	ip link set dev $swp3.111 master br111
148
149	# Make sure that ingress quotas are smaller than egress so that there is
150	# room for both streams of traffic to be admitted to shared buffer.
151	devlink_port_pool_th_save $swp1 0
152	devlink_port_pool_th_set $swp1 0 5
153	devlink_tc_bind_pool_th_save $swp1 0 ingress
154	devlink_tc_bind_pool_th_set $swp1 0 ingress 0 5
155
156	devlink_port_pool_th_save $swp2 0
157	devlink_port_pool_th_set $swp2 0 5
158	devlink_tc_bind_pool_th_save $swp2 1 ingress
159	devlink_tc_bind_pool_th_set $swp2 1 ingress 0 5
160
161	devlink_port_pool_th_save $swp3 4
162	devlink_port_pool_th_set $swp3 4 12
163}
164
165switch_destroy()
166{
167	devlink_port_pool_th_restore $swp3 4
168
169	devlink_tc_bind_pool_th_restore $swp2 1 ingress
170	devlink_port_pool_th_restore $swp2 0
171
172	devlink_tc_bind_pool_th_restore $swp1 0 ingress
173	devlink_port_pool_th_restore $swp1 0
174
175	ip link del dev br111
176	ip link del dev br1
177
178	tc qdisc del dev $swp3 parent 3:3 handle 33:
179	tc qdisc del dev $swp3 root handle 3:
180
181	vlan_destroy $swp3 111
182	vlan_destroy $swp2 111
183
184	mtu_restore $swp3
185	ip link set dev $swp3 down
186
187	mtu_restore $swp2
188	ip link set dev $swp2 down
189
190	mtu_restore $swp1
191	ip link set dev $swp1 down
192}
193
194setup_prepare()
195{
196	h1=${NETIFS[p1]}
197	swp1=${NETIFS[p2]}
198
199	swp2=${NETIFS[p3]}
200	h2=${NETIFS[p4]}
201
202	swp3=${NETIFS[p5]}
203	h3=${NETIFS[p6]}
204
205	h3mac=$(mac_get $h3)
206
207	vrf_prepare
208
209	h1_create
210	h2_create
211	h3_create
212	switch_create
213}
214
215cleanup()
216{
217	pre_cleanup
218
219	switch_destroy
220	h3_destroy
221	h2_destroy
222	h1_destroy
223
224	vrf_cleanup
225}
226
227ping_ipv4()
228{
229	ping_test $h2 192.0.2.130
230}
231
232test_mc_aware()
233{
234	RET=0
235
236	local -a uc_rate
237	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
238	uc_rate=($(measure_rate $swp2 $h3 rx_octets_prio_1 "UC-only"))
239	check_err $? "Could not get high enough UC-only ingress rate"
240	stop_traffic
241	local ucth1=${uc_rate[1]}
242
243	start_traffic $h1 192.0.2.65 bc bc
244
245	local d0=$(date +%s)
246	local t0=$(ethtool_stats_get $h3 rx_octets_prio_0)
247	local u0=$(ethtool_stats_get $swp1 rx_octets_prio_0)
248
249	local -a uc_rate_2
250	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
251	uc_rate_2=($(measure_rate $swp2 $h3 rx_octets_prio_1 "UC+MC"))
252	check_err $? "Could not get high enough UC+MC ingress rate"
253	stop_traffic
254	local ucth2=${uc_rate_2[1]}
255
256	local d1=$(date +%s)
257	local t1=$(ethtool_stats_get $h3 rx_octets_prio_0)
258	local u1=$(ethtool_stats_get $swp1 rx_octets_prio_0)
259
260	local deg=$(bc <<< "
261			scale=2
262			ret = 100 * ($ucth1 - $ucth2) / $ucth1
263			if (ret > 0) { ret } else { 0 }
264		    ")
265
266	# Minimum shaper of 200Mbps on MC TCs should cause about 20% of
267	# degradation on 1Gbps link.
268	check_err $(bc <<< "$deg < 15") "Minimum shaper not in effect"
269	check_err $(bc <<< "$deg > 25") "MC traffic degrades UC performance too much"
270
271	local interval=$((d1 - d0))
272	local mc_ir=$(rate $u0 $u1 $interval)
273	local mc_er=$(rate $t0 $t1 $interval)
274
275	stop_traffic
276
277	log_test "UC performance under MC overload"
278
279	echo "UC-only throughput  $(humanize $ucth1)"
280	echo "UC+MC throughput    $(humanize $ucth2)"
281	echo "Degradation         $deg %"
282	echo
283	echo "Full report:"
284	echo "  UC only:"
285	echo "    ingress UC throughput $(humanize ${uc_rate[0]})"
286	echo "    egress UC throughput  $(humanize ${uc_rate[1]})"
287	echo "  UC+MC:"
288	echo "    ingress UC throughput $(humanize ${uc_rate_2[0]})"
289	echo "    egress UC throughput  $(humanize ${uc_rate_2[1]})"
290	echo "    ingress MC throughput $(humanize $mc_ir)"
291	echo "    egress MC throughput  $(humanize $mc_er)"
292	echo
293}
294
295test_uc_aware()
296{
297	RET=0
298
299	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
300
301	local d0=$(date +%s)
302	local t0=$(ethtool_stats_get $h3 rx_octets_prio_1)
303	local u0=$(ethtool_stats_get $swp2 rx_octets_prio_1)
304	sleep 1
305
306	local attempts=50
307	local passes=0
308	local i
309
310	for ((i = 0; i < attempts; ++i)); do
311		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 1; then
312			((passes++))
313		fi
314
315		sleep 0.1
316	done
317
318	local d1=$(date +%s)
319	local t1=$(ethtool_stats_get $h3 rx_octets_prio_1)
320	local u1=$(ethtool_stats_get $swp2 rx_octets_prio_1)
321
322	local interval=$((d1 - d0))
323	local uc_ir=$(rate $u0 $u1 $interval)
324	local uc_er=$(rate $t0 $t1 $interval)
325
326	((attempts == passes))
327	check_err $?
328
329	stop_traffic
330
331	log_test "MC performance under UC overload"
332	echo "    ingress UC throughput $(humanize ${uc_ir})"
333	echo "    egress UC throughput  $(humanize ${uc_er})"
334	echo "    sent $attempts BC ARPs, got $passes responses"
335}
336
337trap cleanup EXIT
338
339setup_prepare
340setup_wait
341
342tests_run
343
344exit $EXIT_STATUS
345