This is a very reasonable use case for multiqueue NIC, add it to
tc-testing to ensure no one should break it.

Test 94a8: Test MQ with NETEM duplication
[  753.877611] v0p0id94a8: entered promiscuous mode
[  753.909783] virtio_net virtio0 enp1s0: entered promiscuous mode
[  753.936686] virtio_net virtio0 enp1s0: left promiscuous mode
.
Sent 1 packets.
[  753.984974] v0p0id94a8: left promiscuous mode
[  754.010725] v0p0id94a8: entered promiscuous mode
.
Sent 1 packets.
[  754.030879] v0p0id94a8: left promiscuous mode
[  754.067966] v0p0id94a8: entered promiscuous mode
.
Sent 1 packets.
[  754.096516] v0p0id94a8: left promiscuous mode
[  754.129166] v0p0id94a8: entered promiscuous mode
.
Sent 1 packets.
[  754.156371] v0p0id94a8: left promiscuous mode
[  754.187278] v0p0id94a8: entered promiscuous mode
.
Sent 1 packets.
[  754.212102] v0p0id94a8: left promiscuous mode

All test results:

1..1
ok 1 94a8 - Test MQ with NETEM duplication

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 .../tc-testing/tc-tests/infra/qdiscs.json     | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json b/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json
index bfa6de751270..8e206260fa79 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json
@@ -701,5 +701,35 @@
         "teardown": [
             "$TC qdisc del dev $DUMMY root handle 1: prio"
         ]
+    },
+    {
+        "id": "94a8",
+        "name": "Test MQ with NETEM duplication",
+        "category": [
+            "qdisc",
+            "mq",
+            "netem"
+        ],
+        "plugins": {
+            "requires": ["nsPlugin", "scapyPlugin"]
+        },
+        "setup": [
+            "$IP link set dev $DEV1 up",
+            "$TC qdisc add dev $DEV1 root handle 1: mq",
+            "$TC qdisc add dev $DEV1 parent 1:1 handle 10: netem duplicate 100%"
+        ],
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 5,
+            "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+        },
+        "cmdUnderTest": "$TC -s qdisc show dev $DEV1",
+        "expExitCode": "0",
+        "verifyCmd": "$TC -s qdisc show dev $DEV1 | grep -A 5 'qdisc netem' | grep -E 'Sent [0-9]+ bytes [0-9]+ pkt'",
+        "matchPattern": "Sent \\d+ bytes (\\d+) pkt",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 root handle 1: mq"
+        ]
     }
 ]
-- 
2.34.1