[PATCH v4 2/2] selftests/rdma: Add netkit-based automated test script for RXE

[Zhu Yanjun <yanjun.zhu@linux.dev>]

Add a shell script to automate functional and tracing tests for the
Soft-RoCE (RXE) driver over netkit network interfaces. The script creates
an isolated network namespace, sets up a netkit link pair (nk0/nk1),
attaches RXE links, and runs an rping client/server verification test
along with kernel tracing output collection.

Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
---
 .../testing/selftests/rdma/rxe_pkg_netkit.sh  | 81 +++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100755 tools/testing/selftests/rdma/rxe_pkg_netkit.sh

diff --git a/tools/testing/selftests/rdma/rxe_pkg_netkit.sh b/tools/testing/selftests/rdma/rxe_pkg_netkit.sh
new file mode 100755
index 000000000000..181e2d85eed7
--- /dev/null
+++ b/tools/testing/selftests/rdma/rxe_pkg_netkit.sh
@@ -0,0 +1,81 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+# Copyright (c) 2026 Zhu Yanjun <yanjun.zhu@linux.dev>
+if [ "$(id -u)" -ne 0 ]; then
+    echo "SKIP: This test must be run as root"
+    exit 4
+fi
+
+for cmd in ip rdma rping; do
+    if ! command -v "$cmd" >/dev/null 2>&1; then
+        echo "SKIP: Required tool '$cmd' not found"
+        exit 4
+    fi
+done
+
+if ! modprobe -n netkit >/dev/null 2>&1 || ! modprobe -n rdma_rxe >/dev/null 2>&1; then
+    echo "SKIP: Required kernel modules (netkit or rdma_rxe) are not available"
+    exit 4
+fi
+
+exec > /dev/null
+
+set -e
+
+CUR_WD="$(dirname "$0")"
+[ "$CUR_WD" = "." ] && CUR_WD="$(pwd)"
+
+cleanup() {
+    set +e
+    [ -n "$DUMP_PID" ] && kill -9 "$DUMP_PID" 2>/dev/null
+    unset DUMP_PID
+
+    rdma link del rxe1 2>/dev/null
+    ip link del nk0 2>/dev/null
+    ip netns delete ns0 2>/dev/null
+}
+
+trap cleanup EXIT INT TERM
+
+# Clear tracing buffer
+echo > /sys/kernel/debug/tracing/trace
+
+# Create network namespace and netkit peer links
+ip netns add ns0
+ip link add nk0 type netkit mode l2 peer name nk1
+ip link set nk0 up
+ip link set nk1 up
+
+# Configure namespace interface
+ip link set nk1 netns ns0
+ip netns exec ns0 ip addr add 10.0.0.1/24 dev nk1
+ip netns exec ns0 ip link set nk1 up
+
+# Configure host interface
+ip addr add 10.0.0.2/24 dev nk0
+
+# Start dump utility in background
+"$CUR_WD/rxe_netkit_dump" &
+DUMP_PID=$!
+
+# Add RXE links over netkit devices
+ip netns exec ns0 rdma link add rxe0 type rxe netdev nk1
+rdma link add rxe1 type rxe netdev nk0
+
+# Start rping server in namespace
+ip netns exec ns0 rping -s -a 10.0.0.1 -C 3 &
+
+# Add wait time
+sleep 1
+
+# Run rping client on host
+rping -c -a 10.0.0.1 -C 3
+
+# Tear down RDMA links and netkit devices
+ip netns exec ns0 rdma link del rxe0
+rdma link del rxe1
+ip link del nk0
+ip netns delete ns0
+
+# Display kernel trace output
+cat /sys/kernel/debug/tracing/trace
-- 
2.54.0