[PATCH net-next v4 8/8] selftests: drv-net: add netkit devmem tests

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add nk_devmem.py with four tests for TCP devmem through a netkit device:

These tests are just duplicates of the original devmem tests, with some
adjusted parameters such as telling ncdevmem to avoid device setup
(since it only has access to netkit, not a phys device).

Each test uses NetDrvContEnv with primary_rx_redirect=True to set up the
BPF redirect program on the primary netkit interface.

The NIC (HDS, RSS, queue lease) is configured once in main() before
ksft_run() and torn down in a finally block via cleanup_nic(), mirroring
the nk_qlease.py pattern. This avoids re-toggling NIC settings around
every test case.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v4:
- Call configure_nic()/cleanup_nic() once around ksft_run() rather than
  relying on per-test configuration inside the run_* helpers.

Changes in v3:
- Reorder os.path expressions
- Drop @ksft_disruptive from check_nk_rx_hds to mirror the original
  check_rx_hds in devmem.py

Changes in v2:
- Add nk_devmem.py to TEST_PROGS in Makefile (Sashiko)
---
 tools/testing/selftests/drivers/net/hw/Makefile    |  1 +
 .../testing/selftests/drivers/net/hw/nk_devmem.py  | 55 ++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 85ca4d1ecf9e..2f78c6aec397 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -34,6 +34,7 @@ TEST_PROGS = \
 	irq.py \
 	loopback.sh \
 	nic_timestamp.py \
+	nk_devmem.py \
 	nk_netns.py \
 	nk_qlease.py \
 	ntuple.py \
diff --git a/tools/testing/selftests/drivers/net/hw/nk_devmem.py b/tools/testing/selftests/drivers/net/hw/nk_devmem.py
new file mode 100755
index 000000000000..0e36a0fa9688
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/nk_devmem.py
@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+"""Test devmem TCP with netkit."""
+
+import os
+from lib.py import ksft_run, ksft_exit, ksft_disruptive
+from lib.py import NetDrvContEnv
+from lib.py.devmem import (setup_test, require_devmem, configure_nic,
+                           cleanup_nic, run_rx, run_tx, run_tx_chunks,
+                           run_rx_hds)
+
+
+@ksft_disruptive
+def check_nk_rx(cfg) -> None:
+    """Run the devmem RX test through netkit."""
+    run_rx(cfg)
+
+
+@ksft_disruptive
+def check_nk_tx(cfg) -> None:
+    """Run the devmem TX test through netkit."""
+    run_tx(cfg)
+
+
+@ksft_disruptive
+def check_nk_tx_chunks(cfg) -> None:
+    """Run the devmem TX chunking test through netkit."""
+    run_tx_chunks(cfg)
+
+
+def check_nk_rx_hds(cfg) -> None:
+    """Run the HDS test through netkit."""
+    run_rx_hds(cfg)
+
+
+def main() -> None:
+    """Configure the NIC once, then run the netkit devmem test cases."""
+    with NetDrvContEnv(__file__, rxqueues=2, primary_rx_redirect=True) as cfg:
+        setup_test(cfg,
+                   os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                                "ncdevmem"))
+
+        require_devmem(cfg)
+        configure_nic(cfg)
+        try:
+            ksft_run([check_nk_rx, check_nk_tx, check_nk_tx_chunks,
+                      check_nk_rx_hds], args=(cfg,))
+        finally:
+            cleanup_nic(cfg)
+
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()

-- 
2.53.0-Meta