cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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qos_mc_aware.sh (9412B)


      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	ethtool -s $swp3 speed 1000 autoneg off
    133	tc qdisc replace dev $swp3 root handle 3: \
    134	   prio bands 8 priomap 7 7 7 7 7 7 7 7
    135
    136	ip link add name br1 type bridge vlan_filtering 0
    137	ip link set dev br1 up
    138	ip link set dev $swp1 master br1
    139	ip link set dev $swp3 master br1
    140
    141	ip link add name br111 type bridge vlan_filtering 0
    142	ip link set dev br111 up
    143	ip link set dev $swp2.111 master br111
    144	ip link set dev $swp3.111 master br111
    145
    146	# Make sure that ingress quotas are smaller than egress so that there is
    147	# room for both streams of traffic to be admitted to shared buffer.
    148	devlink_port_pool_th_save $swp1 0
    149	devlink_port_pool_th_set $swp1 0 5
    150	devlink_tc_bind_pool_th_save $swp1 0 ingress
    151	devlink_tc_bind_pool_th_set $swp1 0 ingress 0 5
    152
    153	devlink_port_pool_th_save $swp2 0
    154	devlink_port_pool_th_set $swp2 0 5
    155	devlink_tc_bind_pool_th_save $swp2 1 ingress
    156	devlink_tc_bind_pool_th_set $swp2 1 ingress 0 5
    157
    158	devlink_port_pool_th_save $swp3 4
    159	devlink_port_pool_th_set $swp3 4 12
    160}
    161
    162switch_destroy()
    163{
    164	devlink_port_pool_th_restore $swp3 4
    165
    166	devlink_tc_bind_pool_th_restore $swp2 1 ingress
    167	devlink_port_pool_th_restore $swp2 0
    168
    169	devlink_tc_bind_pool_th_restore $swp1 0 ingress
    170	devlink_port_pool_th_restore $swp1 0
    171
    172	ip link del dev br111
    173	ip link del dev br1
    174
    175	tc qdisc del dev $swp3 root handle 3:
    176	ethtool -s $swp3 autoneg on
    177
    178	vlan_destroy $swp3 111
    179	vlan_destroy $swp2 111
    180
    181	mtu_restore $swp3
    182	ip link set dev $swp3 down
    183
    184	mtu_restore $swp2
    185	ip link set dev $swp2 down
    186
    187	mtu_restore $swp1
    188	ip link set dev $swp1 down
    189}
    190
    191setup_prepare()
    192{
    193	h1=${NETIFS[p1]}
    194	swp1=${NETIFS[p2]}
    195
    196	swp2=${NETIFS[p3]}
    197	h2=${NETIFS[p4]}
    198
    199	swp3=${NETIFS[p5]}
    200	h3=${NETIFS[p6]}
    201
    202	h3mac=$(mac_get $h3)
    203
    204	vrf_prepare
    205
    206	h1_create
    207	h2_create
    208	h3_create
    209	switch_create
    210}
    211
    212cleanup()
    213{
    214	pre_cleanup
    215
    216	switch_destroy
    217	h3_destroy
    218	h2_destroy
    219	h1_destroy
    220
    221	vrf_cleanup
    222}
    223
    224ping_ipv4()
    225{
    226	ping_test $h2 192.0.2.130
    227}
    228
    229test_mc_aware()
    230{
    231	RET=0
    232
    233	local -a uc_rate
    234	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
    235	uc_rate=($(measure_rate $swp2 $h3 rx_octets_prio_1 "UC-only"))
    236	check_err $? "Could not get high enough UC-only ingress rate"
    237	stop_traffic
    238	local ucth1=${uc_rate[1]}
    239
    240	start_traffic $h1 192.0.2.65 bc bc
    241
    242	local d0=$(date +%s)
    243	local t0=$(ethtool_stats_get $h3 rx_octets_prio_0)
    244	local u0=$(ethtool_stats_get $swp1 rx_octets_prio_0)
    245
    246	local -a uc_rate_2
    247	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
    248	uc_rate_2=($(measure_rate $swp2 $h3 rx_octets_prio_1 "UC+MC"))
    249	check_err $? "Could not get high enough UC+MC ingress rate"
    250	stop_traffic
    251	local ucth2=${uc_rate_2[1]}
    252
    253	local d1=$(date +%s)
    254	local t1=$(ethtool_stats_get $h3 rx_octets_prio_0)
    255	local u1=$(ethtool_stats_get $swp1 rx_octets_prio_0)
    256
    257	local deg=$(bc <<< "
    258			scale=2
    259			ret = 100 * ($ucth1 - $ucth2) / $ucth1
    260			if (ret > 0) { ret } else { 0 }
    261		    ")
    262
    263	# Minimum shaper of 200Mbps on MC TCs should cause about 20% of
    264	# degradation on 1Gbps link.
    265	check_err $(bc <<< "$deg < 15") "Minimum shaper not in effect"
    266	check_err $(bc <<< "$deg > 25") "MC traffic degrades UC performance too much"
    267
    268	local interval=$((d1 - d0))
    269	local mc_ir=$(rate $u0 $u1 $interval)
    270	local mc_er=$(rate $t0 $t1 $interval)
    271
    272	stop_traffic
    273
    274	log_test "UC performance under MC overload"
    275
    276	echo "UC-only throughput  $(humanize $ucth1)"
    277	echo "UC+MC throughput    $(humanize $ucth2)"
    278	echo "Degradation         $deg %"
    279	echo
    280	echo "Full report:"
    281	echo "  UC only:"
    282	echo "    ingress UC throughput $(humanize ${uc_rate[0]})"
    283	echo "    egress UC throughput  $(humanize ${uc_rate[1]})"
    284	echo "  UC+MC:"
    285	echo "    ingress UC throughput $(humanize ${uc_rate_2[0]})"
    286	echo "    egress UC throughput  $(humanize ${uc_rate_2[1]})"
    287	echo "    ingress MC throughput $(humanize $mc_ir)"
    288	echo "    egress MC throughput  $(humanize $mc_er)"
    289	echo
    290}
    291
    292test_uc_aware()
    293{
    294	RET=0
    295
    296	start_traffic $h2.111 192.0.2.129 192.0.2.130 $h3mac
    297
    298	local d0=$(date +%s)
    299	local t0=$(ethtool_stats_get $h3 rx_octets_prio_1)
    300	local u0=$(ethtool_stats_get $swp2 rx_octets_prio_1)
    301	sleep 1
    302
    303	local attempts=50
    304	local passes=0
    305	local i
    306
    307	for ((i = 0; i < attempts; ++i)); do
    308		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 1; then
    309			((passes++))
    310		fi
    311
    312		sleep 0.1
    313	done
    314
    315	local d1=$(date +%s)
    316	local t1=$(ethtool_stats_get $h3 rx_octets_prio_1)
    317	local u1=$(ethtool_stats_get $swp2 rx_octets_prio_1)
    318
    319	local interval=$((d1 - d0))
    320	local uc_ir=$(rate $u0 $u1 $interval)
    321	local uc_er=$(rate $t0 $t1 $interval)
    322
    323	((attempts == passes))
    324	check_err $?
    325
    326	stop_traffic
    327
    328	log_test "MC performance under UC overload"
    329	echo "    ingress UC throughput $(humanize ${uc_ir})"
    330	echo "    egress UC throughput  $(humanize ${uc_er})"
    331	echo "    sent $attempts BC ARPs, got $passes responses"
    332}
    333
    334trap cleanup EXIT
    335
    336setup_prepare
    337setup_wait
    338
    339tests_run
    340
    341exit $EXIT_STATUS