net: selftest: add test for netdev netlink queue-get API

Add a selftest for netdev generic netlink. For now there is only a
single test that exercises the `queue-get` API.

The test works with netdevsim by default or with a real device by
setting NETIF.

Add a timeout param to cmd() since ethtool -L can take a long time on
real devices.

Signed-off-by: David Wei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

1 files changed, 66 insertions, 0 deletions

diff --git a/tools/testing/selftests/drivers/net/queues.py b/tools/testing/selftests/drivers/net/queues.py
new file mode 100755
index 000000000000..30f29096e27c
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/queues.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+from lib.py import ksft_run, ksft_exit, ksft_eq, KsftSkipEx
+from lib.py import EthtoolFamily, NetdevFamily
+from lib.py import NetDrvEnv
+from lib.py import cmd
+import glob
+
+
+def sys_get_queues(ifname) -> int:
+    folders = glob.glob(f'/sys/class/net/{ifname}/queues/rx-*')
+    return len(folders)
+
+
+def nl_get_queues(cfg, nl):
+    queues = nl.queue_get({'ifindex': cfg.ifindex}, dump=True)
+    if queues:
+        return len([q for q in queues if q['type'] == 'rx'])
+    return None
+
+
+def get_queues(cfg, nl) -> None:
+    queues = nl_get_queues(cfg, nl)
+    if not queues:
+        raise KsftSkipEx('queue-get not supported by device')
+
+    expected = sys_get_queues(cfg.dev['ifname'])
+    ksft_eq(queues, expected)
+
+
+def addremove_queues(cfg, nl) -> None:
+    queues = nl_get_queues(cfg, nl)
+    if not queues:
+        raise KsftSkipEx('queue-get not supported by device')
+
+    curr_queues = sys_get_queues(cfg.dev['ifname'])
+    if curr_queues == 1:
+        raise KsftSkipEx('cannot decrement queue: already at 1')
+
+    netnl = EthtoolFamily()
+    channels = netnl.channels_get({'header': {'dev-index': cfg.ifindex}})
+    if channels['combined-count'] == 0:
+        rx_type = 'rx'
+    else:
+        rx_type = 'combined'
+
+    expected = curr_queues - 1
+    cmd(f"ethtool -L {cfg.dev['ifname']} {rx_type} {expected}", timeout=10)
+    queues = nl_get_queues(cfg, nl)
+    ksft_eq(queues, expected)
+
+    expected = curr_queues
+    cmd(f"ethtool -L {cfg.dev['ifname']} {rx_type} {expected}", timeout=10)
+    queues = nl_get_queues(cfg, nl)
+    ksft_eq(queues, expected)
+
+
+def main() -> None:
+    with NetDrvEnv(__file__, queue_count=3) as cfg:
+        ksft_run([get_queues, addremove_queues], args=(cfg, NetdevFamily()))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()