Only RX side for now and small message to test the setup.
In the future, we can extend it to TX side and to testing
both sides with a couple of megs of data.

  make \
  	-C tools/testing/selftests \
  	TARGETS="drivers/hw/net" \
  	install INSTALL_PATH=~/tmp/ksft

  scp ~/tmp/ksft ${HOST}:
  scp ~/tmp/ksft ${PEER}:

  cfg+="NETIF=${DEV}\n"
  cfg+="LOCAL_V6=${HOST_IP}\n"
  cfg+="REMOTE_V6=${PEER_IP}\n"
  cfg+="REMOTE_TYPE=ssh\n"
  cfg+="REMOTE_ARGS=root@${PEER}\n"

  echo -e "$cfg" | ssh root@${HOST} "cat > ksft/drivers/net/net.config"
  ssh root@${HOST} "cd ksft && ./run_kselftest.sh -t drivers/net:devmem.py"

Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
---
 .../testing/selftests/drivers/net/hw/Makefile |  1 +
 .../selftests/drivers/net/hw/devmem.py        | 45 +++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100755 tools/testing/selftests/drivers/net/hw/devmem.py

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 182348f4bd40..1c6a77480923 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -3,6 +3,7 @@
 TEST_PROGS = \
 	csum.py \
 	devlink_port_split.py \
+	devmem.py \
 	ethtool.sh \
 	ethtool_extended_state.sh \
 	ethtool_mm.sh \
diff --git a/tools/testing/selftests/drivers/net/hw/devmem.py b/tools/testing/selftests/drivers/net/hw/devmem.py
new file mode 100755
index 000000000000..1416c31ff81e
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/devmem.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+from lib.py import ksft_run, ksft_exit
+from lib.py import ksft_eq, KsftSkipEx
+from lib.py import NetDrvEpEnv
+from lib.py import bkg, cmd, rand_port, wait_port_listen
+from lib.py import ksft_disruptive
+
+
+def require_devmem(cfg):
+    if not hasattr(cfg, "_devmem_probed"):
+        port = rand_port()
+        probe_command = f"./ncdevmem -f {cfg.ifname}"
+        cfg._devmem_supported = cmd(probe_command, fail=False, shell=True).ret == 0
+        cfg._devmem_probed = True
+
+    if not cfg._devmem_supported:
+        raise KsftSkipEx("Test requires devmem support")
+
+
+@ksft_disruptive
+def check_rx(cfg) -> None:
+    cfg.require_v6()
+    require_devmem(cfg)
+
+    port = rand_port()
+    listen_cmd = f"./ncdevmem -l -f {cfg.ifname} -s {cfg.v6} -p {port}"
+
+    with bkg(listen_cmd) as nc:
+        wait_port_listen(port)
+        cmd(f"echo -e \"hello\\nworld\"| nc {cfg.v6} {port}", host=cfg.remote, shell=True)
+
+    ksft_eq(nc.stdout.strip(), "hello\nworld")
+
+
+def main() -> None:
+    with NetDrvEpEnv(__file__) as cfg:
+        ksft_run([check_rx],
+                 args=(cfg, ))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()
-- 
2.47.0