selftests: net: test ethtool -L vs mq

Add a selftest for checking mq children are visible after ethtool -L.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/drivers/net/netdevsim/ethtool-common.sh

@@ -50,7 +50,7 @@ function make_netdev {
 	modprobe netdevsim
     fi
 
-    echo $NSIM_ID > /sys/bus/netdevsim/new_device
+    echo $NSIM_ID $@ > /sys/bus/netdevsim/new_device
     # get new device name
     ls /sys/bus/netdevsim/devices/netdevsim${NSIM_ID}/net/
 }

tools/testing/selftests/drivers/net/netdevsim/tc-mq-visibility.sh

@@ -0,0 +1,77 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+
+source ethtool-common.sh
+
+set -o pipefail
+
+n_children() {
+    n=$(tc qdisc show dev $NDEV | grep '^qdisc' | wc -l)
+    echo $((n - 1))
+}
+
+tcq() {
+    tc qdisc $1 dev $NDEV ${@:2}
+}
+
+n_child_assert() {
+    n=$(n_children)
+    if [ $n -ne $1 ]; then
+	echo "ERROR ($root): ${@:2}, expected $1 have $n"
+	((num_errors++))
+    else
+	((num_passes++))
+    fi
+}
+
+
+for root in mq mqprio; do
+    NDEV=$(make_netdev 1 4)
+
+    opts=
+    [ $root == "mqprio" ] && opts='hw 0 num_tc 1 map 0 0 0 0  queues 1@0'
+
+    tcq add root handle 100: $root $opts
+    n_child_assert 4 'Init'
+
+    # All defaults
+
+    for n in 3 2 1 2 3 4 1 4; do
+	ethtool -L $NDEV combined $n
+	n_child_assert $n "Change queues to $n while down"
+    done
+
+    ip link set dev $NDEV up
+
+    for n in 3 2 1 2 3 4 1 4; do
+	ethtool -L $NDEV combined $n
+	n_child_assert $n "Change queues to $n while up"
+    done
+
+    # One real one
+    tcq replace parent 100:4 handle 204: pfifo_fast
+    n_child_assert 4 "One real queue"
+
+    ethtool -L $NDEV combined 1
+    n_child_assert 2 "One real queue, one default"
+
+    ethtool -L $NDEV combined 4
+    n_child_assert 4 "One real queue, rest default"
+
+    # Graft some
+    tcq replace parent 100:1 handle 204:
+    n_child_assert 3 "Grafted"
+
+    ethtool -L $NDEV combined 1
+    n_child_assert 1 "Grafted, one"
+
+    cleanup_nsim
+done
+
+if [ $num_errors -eq 0 ]; then
+    echo "PASSED all $((num_passes)) checks"
+    exit 0
+else
+    echo "FAILED $num_errors/$((num_errors+num_passes)) checks"
+    exit 1
+fi