[PATCH net-next v2 0/3] selftests: drv-net: Add VLAN test

[PATCH net-next v2 0/3] selftests: drv-net: Add VLAN test

[Ovidiu Panait]

This series adds a selftest that pings over 802.1q, 802.1ad and
QinQ VLAN interfaces with RX VLAN stripping offloads enabled
and disabled.

This series contains only the selftest part of [1].

[1] https://lore.kernel.org/all/20260908164309.59282-1-ovidiu.panait.rb@renesas.com/

v2 changes:
- Added a new commit to check if the ethtool changes were actually applied.
- Allowed for the VLAN IPs to be set from the environment, to avoid
  possible clashes.
- Added Nicolai's Rb tag.

Ovidiu Panait (3):
  selftests: drv-net: Move _set_ethtool_feat() into lib
  selftests: drv-net: Check the features set by set_ethtool_feat()
  selftests: drv-net: Add VLAN test

 .../testing/selftests/drivers/net/gro_lib.py  |  66 +++------
 .../testing/selftests/drivers/net/hw/Makefile |   1 +
 tools/testing/selftests/drivers/net/hw/config |   1 +
 .../drivers/net/hw/lib/py/__init__.py         |   3 +-
 .../testing/selftests/drivers/net/hw/vlan.py  | 127 ++++++++++++++++++
 .../selftests/drivers/net/lib/py/__init__.py  |   3 +-
 .../selftests/drivers/net/lib/py/feat.py      |  43 ++++++
 7 files changed, 197 insertions(+), 47 deletions(-)
 create mode 100755 tools/testing/selftests/drivers/net/hw/vlan.py
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/feat.py

-- 
2.34.1

[PATCH net-next v2 1/3] selftests: drv-net: Move _set_ethtool_feat() into lib

[Ovidiu Panait]

Move the _set_ethtool_feat() helper from gro_lib.py into lib, so that it
can be reused by the VLAN test added in the next commit. Drop the leading
underscore, now that the helper is exported.

Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
---
v2:
- Added Nicolai's "Reviewed-by" tag.

 .../testing/selftests/drivers/net/gro_lib.py  | 65 ++++++-------------
 .../drivers/net/hw/lib/py/__init__.py         |  3 +-
 .../selftests/drivers/net/lib/py/__init__.py  |  3 +-
 .../selftests/drivers/net/lib/py/feat.py      | 35 ++++++++++
 4 files changed, 59 insertions(+), 47 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/feat.py

diff --git a/tools/testing/selftests/drivers/net/gro_lib.py b/tools/testing/selftests/drivers/net/gro_lib.py
index abecf60baa53..7856ebdd49d3 100644
--- a/tools/testing/selftests/drivers/net/gro_lib.py
+++ b/tools/testing/selftests/drivers/net/gro_lib.py
@@ -52,7 +52,7 @@ import re
 from lib.py import ksft_run, ksft_exit, ksft_pr, ksft_eq
 from lib.py import NetDrvEpEnv, KsftFailEx, KsftSkipEx, KsftXfailEx
 from lib.py import NetdevFamily, EthtoolFamily
-from lib.py import bkg, cmd, ctl_file_write, defer, ethtool, ip
+from lib.py import bkg, cmd, ctl_file_write, defer, ethtool, ip, set_ethtool_feat
 from lib.py import ksft_variants, KsftNamedVariant
 
 
@@ -125,31 +125,6 @@ def _set_gro_size_restore(cfg, size):
             comment="gro_ipv4_max_size not applied")
 
 
-def _set_ethtool_feat(dev, current, feats, host=None):
-    s2n = {True: "on", False: "off"}
-
-    new = ["-K", dev]
-    old = ["-K", dev]
-    no_change = True
-    for name, state in feats.items():
-        new += [name, s2n[state]]
-        old += [name, s2n[current[name]["active"]]]
-
-        if current[name]["active"] != state:
-            no_change = False
-            if current[name]["fixed"]:
-                raise KsftXfailEx(f"Device does not support {name}")
-    if no_change:
-        return
-
-    eth_cmd = ethtool(" ".join(new), host=host)
-    defer(ethtool, " ".join(old), host=host)
-
-    # If ethtool printed something kernel must have modified some features
-    if eth_cmd.stdout:
-        ksft_pr(eth_cmd)
-
-
 def _get_queue_stats(cfg, queue_id):
     """Get stats for a specific Rx queue."""
     cfg.wait_hw_stats_settle()
@@ -280,15 +255,15 @@ def _setup(cfg, mode, test_name):
             ctl_file_write(flush_path, "200000")
         ctl_file_write(irq_path, "10")
 
-        _set_ethtool_feat(cfg.ifname, cfg.feat,
-                          {"generic-receive-offload": True,
-                           "rx-gro-hw": False,
-                           "large-receive-offload": False})
+        set_ethtool_feat(cfg.ifname, cfg.feat,
+                         {"generic-receive-offload": True,
+                          "rx-gro-hw": False,
+                          "large-receive-offload": False})
     elif mode == "hw":
-        _set_ethtool_feat(cfg.ifname, cfg.feat,
-                          {"generic-receive-offload": False,
-                           "rx-gro-hw": True,
-                           "large-receive-offload": False})
+        set_ethtool_feat(cfg.ifname, cfg.feat,
+                         {"generic-receive-offload": False,
+                          "rx-gro-hw": True,
+                          "large-receive-offload": False})
 
         # Some NICs treat HW GRO as a GRO sub-feature so disabling GRO
         # will also clear HW GRO. Use a hack of installing XDP generic
@@ -303,27 +278,27 @@ def _setup(cfg, mode, test_name):
             # Attaching XDP may change features, fetch the latest state
             feat = ethtool(f"-k {cfg.ifname}", json=True)[0]
 
-            _set_ethtool_feat(cfg.ifname, feat,
-                              {"generic-receive-offload": True,
-                               "rx-gro-hw": True,
-                               "large-receive-offload": False})
+            set_ethtool_feat(cfg.ifname, feat,
+                             {"generic-receive-offload": True,
+                              "rx-gro-hw": True,
+                              "large-receive-offload": False})
     elif mode == "lro":
         # netdevsim advertises LRO for feature inheritance testing with
         # bonding/team tests but it doesn't actually perform the offload
         cfg.require_nsim(nsim_test=False)
 
-        _set_ethtool_feat(cfg.ifname, cfg.feat,
-                          {"generic-receive-offload": False,
-                           "rx-gro-hw": False,
-                           "large-receive-offload": True})
+        set_ethtool_feat(cfg.ifname, cfg.feat,
+                         {"generic-receive-offload": False,
+                          "rx-gro-hw": False,
+                          "large-receive-offload": True})
 
     try:
         # Disable TSO for local tests
         cfg.require_nsim()  # will raise KsftXfailEx if not running on nsim
 
-        _set_ethtool_feat(cfg.remote_ifname, cfg.remote_feat,
-                          {"tcp-segmentation-offload": False},
-                          host=cfg.remote)
+        set_ethtool_feat(cfg.remote_ifname, cfg.remote_feat,
+                         {"tcp-segmentation-offload": False},
+                         host=cfg.remote)
     except KsftXfailEx:
         pass
 
diff --git a/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py b/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
index 81e1d1865cd5..4077f5f1a1be 100644
--- a/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
+++ b/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
@@ -31,6 +31,7 @@ try:
         ksft_setup, ksft_variants, KsftNamedVariant
     from net.lib.py import ksft_eq, ksft_ge, ksft_in, ksft_is, ksft_lt, \
         ksft_ne, ksft_not_in, ksft_raises, ksft_true, ksft_gt, ksft_not_none
+    from drivers.net.lib.py import set_ethtool_feat
     from drivers.net.lib.py import GenerateTraffic, Remote, Iperf3Runner
     from drivers.net.lib.py import NetDrvEnv, NetDrvEpEnv, NetDrvContEnv
 
@@ -49,7 +50,7 @@ try:
                "ksft_ne", "ksft_not_in", "ksft_raises", "ksft_true", "ksft_gt",
                "ksft_not_none", "ksft_not_none",
                "NetDrvEnv", "NetDrvEpEnv", "NetDrvContEnv", "GenerateTraffic",
-               "Remote", "Iperf3Runner"]
+               "Remote", "Iperf3Runner", "set_ethtool_feat"]
 except ModuleNotFoundError as e:
     print("Failed importing `net` library from kernel sources")
     print(str(e))
diff --git a/tools/testing/selftests/drivers/net/lib/py/__init__.py b/tools/testing/selftests/drivers/net/lib/py/__init__.py
index 591b1e6c7eea..40ccdcf0c378 100644
--- a/tools/testing/selftests/drivers/net/lib/py/__init__.py
+++ b/tools/testing/selftests/drivers/net/lib/py/__init__.py
@@ -48,11 +48,12 @@ try:
                "ksft_not_none", "ksft_not_none"]
 
     from .env import NetDrvEnv, NetDrvEpEnv, NetDrvContEnv
+    from .feat import set_ethtool_feat
     from .load import GenerateTraffic, Iperf3Runner
     from .remote import Remote
 
     __all__ += ["NetDrvEnv", "NetDrvEpEnv", "NetDrvContEnv", "GenerateTraffic",
-                "Remote", "Iperf3Runner"]
+                "Remote", "Iperf3Runner", "set_ethtool_feat"]
 except ModuleNotFoundError as e:
     print("Failed importing `net` library from kernel sources")
     print(str(e))
diff --git a/tools/testing/selftests/drivers/net/lib/py/feat.py b/tools/testing/selftests/drivers/net/lib/py/feat.py
new file mode 100644
index 000000000000..b94a24214e59
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/lib/py/feat.py
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Netdev feature helper utilities for kernel selftests.
+
+Provides common operations for changing device features via ethtool.
+"""
+
+from . import KsftXfailEx, defer, ethtool, ksft_pr
+
+
+def set_ethtool_feat(dev, current, feats, host=None):
+    """Set ethtool features with defer to restore original state."""
+    s2n = {True: "on", False: "off"}
+
+    new = ["-K", dev]
+    old = ["-K", dev]
+    no_change = True
+    for name, state in feats.items():
+        new += [name, s2n[state]]
+        old += [name, s2n[current[name]["active"]]]
+
+        if current[name]["active"] != state:
+            no_change = False
+            if current[name]["fixed"]:
+                raise KsftXfailEx(f"Device does not support {name}")
+    if no_change:
+        return
+
+    eth_cmd = ethtool(" ".join(new), host=host)
+    defer(ethtool, " ".join(old), host=host)
+
+    # If ethtool printed something kernel must have modified some features
+    if eth_cmd.stdout:
+        ksft_pr(eth_cmd)
-- 
2.34.1

[PATCH net-next v2 2/3] selftests: drv-net: Check the features set by set_ethtool_feat()

[Ovidiu Panait]

Read back the features after running ethtool -K to check if they were
actually applied. The drivers might refuse to set a feature silently and
the test could run with a different configuration than the requested one.

Add a 'check' parameter to skip this, as the GRO "hw" mode handles the
case where HW GRO is cleared by the driver.

Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
---
v2: New patch.

 tools/testing/selftests/drivers/net/gro_lib.py     |  3 ++-
 tools/testing/selftests/drivers/net/lib/py/feat.py | 10 +++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/gro_lib.py b/tools/testing/selftests/drivers/net/gro_lib.py
index 7856ebdd49d3..875a715b2ae1 100644
--- a/tools/testing/selftests/drivers/net/gro_lib.py
+++ b/tools/testing/selftests/drivers/net/gro_lib.py
@@ -263,7 +263,8 @@ def _setup(cfg, mode, test_name):
         set_ethtool_feat(cfg.ifname, cfg.feat,
                          {"generic-receive-offload": False,
                           "rx-gro-hw": True,
-                          "large-receive-offload": False})
+                          "large-receive-offload": False},
+                          check=False)
 
         # Some NICs treat HW GRO as a GRO sub-feature so disabling GRO
         # will also clear HW GRO. Use a hack of installing XDP generic
diff --git a/tools/testing/selftests/drivers/net/lib/py/feat.py b/tools/testing/selftests/drivers/net/lib/py/feat.py
index b94a24214e59..f0630844f023 100644
--- a/tools/testing/selftests/drivers/net/lib/py/feat.py
+++ b/tools/testing/selftests/drivers/net/lib/py/feat.py
@@ -9,7 +9,7 @@ Provides common operations for changing device features via ethtool.
 from . import KsftXfailEx, defer, ethtool, ksft_pr
 
 
-def set_ethtool_feat(dev, current, feats, host=None):
+def set_ethtool_feat(dev, current, feats, host=None, check=True):
     """Set ethtool features with defer to restore original state."""
     s2n = {True: "on", False: "off"}
 
@@ -33,3 +33,11 @@ def set_ethtool_feat(dev, current, feats, host=None):
     # If ethtool printed something kernel must have modified some features
     if eth_cmd.stdout:
         ksft_pr(eth_cmd)
+
+    if not check:
+        return
+
+    current = ethtool(f"-k {dev}", json=True, host=host)[0]
+    for name, state in feats.items():
+        if current[name]["active"] != state:
+            raise KsftXfailEx(f"{name} was not set to {s2n[state]}")
-- 
2.34.1

[PATCH net-next v2 3/3] selftests: drv-net: Add VLAN test

[Ovidiu Panait]

Add a test that validates ping traffic over VLAN interfaces. It aims
to catch drivers which mishandle hardware VLAN tag stripping, in
particular QinQ.

Three VLAN configurations are covered, each with hardware RX VLAN
stripping enabled and disabled (via the rx-vlan-offload and
rx-vlan-stag-hw-parse features):
- a single 802.1q VLAN interface
- a single 802.1ad VLAN interface
- an 802.1q VLAN stacked on top of an 802.1ad interface

The "hw" test variants enable the RX VLAN stripping features supported
by the device (rx-vlan-offload and rx-vlan-stag-hw-parse), the "sw"
test variants disable all of them. A test is xfailed if the requested
configuration is not possible.

VLAN insertion offloads are not tested for now.

NETIF=end0 LOCAL_V4=172.16.0.2 REMOTE_V4=172.16.0.3 \
REMOTE_TYPE=ssh REMOTE_ARGS=root@172.16.0.3 \
run_kselftest.sh -t drivers/net/hw:vlan.py
 TAP version 13
 1..1
 # timeout set to 0
 # selftests: drivers/net/hw: vlan.py
 # # Interface: end0, driver: st_gmac
 # TAP version 13
 # 1..6
 # ok 1 vlan.test.8021q_hw
 # ok 2 vlan.test.8021q_sw
 # ok 3 vlan.test.8021ad_hw
 # ok 4 vlan.test.8021ad_sw
 # ok 5 vlan.test.qinq_hw
 # ok 6 vlan.test.qinq_sw
 # # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0
 ok 1 selftests: drivers/net/hw: vlan.py
 # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
---
v2:
- Allowed the VLAN test IPs to be set from the environment, to avoid
  possible clashes.

 .../testing/selftests/drivers/net/hw/Makefile |   1 +
 tools/testing/selftests/drivers/net/hw/config |   1 +
 .../testing/selftests/drivers/net/hw/vlan.py  | 127 ++++++++++++++++++
 3 files changed, 129 insertions(+)
 create mode 100755 tools/testing/selftests/drivers/net/hw/vlan.py

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 8aebdc6feb17..18ce235a77f8 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -50,6 +50,7 @@ TEST_PROGS = \
 	tso.py \
 	userns_devmem.py \
 	uso.py \
+	vlan.py \
 	xdp_metadata.py \
 	xsk_reconfig.py \
 	#
diff --git a/tools/testing/selftests/drivers/net/hw/config b/tools/testing/selftests/drivers/net/hw/config
index d89a9ba17655..c6c2b64bb712 100644
--- a/tools/testing/selftests/drivers/net/hw/config
+++ b/tools/testing/selftests/drivers/net/hw/config
@@ -24,5 +24,6 @@ CONFIG_NET_SCH_INGRESS=y
 CONFIG_SYNC_FILE=y
 CONFIG_UDMABUF=y
 CONFIG_USER_NS=y
+CONFIG_VLAN_8021Q=m
 CONFIG_VXLAN=y
 CONFIG_XFRM_USER=y
diff --git a/tools/testing/selftests/drivers/net/hw/vlan.py b/tools/testing/selftests/drivers/net/hw/vlan.py
new file mode 100755
index 000000000000..00c90b930f67
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/vlan.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+VLAN tests.
+
+Validates that ping traffic is sent and received correctly over 802.1q
+and 802.1ad VLAN interfaces, with hardware RX VLAN stripping enabled and
+disabled on the local interface.
+
+The "hw" test variants enable the RX VLAN stripping features supported by
+the device, the "sw" test variants disable all of them. A test is xfailed
+if the requested configuration is not possible.
+
+Test cases:
+  - 8021q_hw:  Traffic over a single 802.1q VLAN, HW stripping on
+  - 8021q_sw:  Traffic over a single 802.1q VLAN, HW stripping off
+  - 8021ad_hw: Traffic over a single 802.1ad VLAN, HW stripping on
+  - 8021ad_sw: Traffic over a single 802.1ad VLAN, HW stripping off
+  - qinq_hw:   Traffic over an 802.1q VLAN stacked on an 802.1ad VLAN,
+               HW stripping on
+  - qinq_sw:   Traffic over an 802.1q VLAN stacked on an 802.1ad VLAN,
+               HW stripping off
+"""
+
+import os
+
+from lib.py import (
+    KsftNamedVariant,
+    KsftXfailEx,
+    NetDrvEpEnv,
+    cmd,
+    defer,
+    ethtool,
+    ip,
+    ksft_exit,
+    ksft_run,
+    ksft_variants,
+    set_ethtool_feat,
+)
+
+OUTER_DEV = f"vlout{os.getpid()}"
+INNER_DEV = f"vlin{os.getpid()}"
+
+OUTER_VID = 100
+INNER_VID = 200
+
+LOCAL_IP = os.environ.get("VLAN_LOCAL_V4", "198.51.100.1")
+REMOTE_IP = os.environ.get("VLAN_REMOTE_V4", "198.51.100.2")
+
+
+def _vlan_add(base, name, proto, vid, host=None):
+    """Create a VLAN device on top of base and bring it up."""
+
+    ip(f"link add link {base} name {name} type vlan proto {proto} id {vid}",
+       host=host)
+    defer(ip, f"link del {name}", host=host)
+    ip(f"link set {name} up", host=host)
+
+
+def _vlan_setup(base, addr, outer_proto, inner_proto, host=None):
+    """Create VLAN interfaces on base and set an IP on the innermost one."""
+
+    _vlan_add(base, OUTER_DEV, outer_proto, OUTER_VID, host=host)
+    if inner_proto:
+        _vlan_add(OUTER_DEV, INNER_DEV, inner_proto, INNER_VID, host=host)
+
+    dev = INNER_DEV if inner_proto else OUTER_DEV
+    ip(f"addr add {addr}/24 dev {dev}", host=host)
+
+
+def _setup(cfg, outer_proto, inner_proto, hw_strip):
+    """Configure VLAN stripping and create the VLAN interfaces."""
+
+    names = ["rx-vlan-offload"]
+    if outer_proto == "802.1ad":
+        names.append("rx-vlan-stag-hw-parse")
+
+    feat = ethtool(f"-k {cfg.ifname}", json=True)[0]
+    feats = {}
+    for name in names:
+        # hw: skip the features the device does not support
+        # sw: request all of them off
+        if hw_strip and feat[name]["fixed"] and not feat[name]["active"]:
+            continue
+        feats[name] = hw_strip
+
+    if hw_strip and not feats:
+        raise KsftXfailEx("Device does not support RX VLAN stripping")
+
+    set_ethtool_feat(cfg.ifname, feat, feats)
+
+    _vlan_setup(cfg.ifname, LOCAL_IP, outer_proto, inner_proto)
+    _vlan_setup(cfg.remote_ifname, REMOTE_IP, outer_proto, inner_proto,
+                host=cfg.remote)
+
+
+def _vlan_variants():
+    """Generator that yields the VLAN protocols and the stripping mode."""
+
+    yield KsftNamedVariant("8021q_hw", "802.1q", None, True)
+    yield KsftNamedVariant("8021q_sw", "802.1q", None, False)
+    yield KsftNamedVariant("8021ad_hw", "802.1ad", None, True)
+    yield KsftNamedVariant("8021ad_sw", "802.1ad", None, False)
+    yield KsftNamedVariant("qinq_hw", "802.1ad", "802.1q", True)
+    yield KsftNamedVariant("qinq_sw", "802.1ad", "802.1q", False)
+
+
+@ksft_variants(_vlan_variants())
+def test(cfg, outer_proto, inner_proto, hw_strip):
+    """Run a single VLAN test"""
+
+    _setup(cfg, outer_proto, inner_proto, hw_strip)
+
+    cmd(f"ping -c 1 -W 5 {REMOTE_IP}")
+
+
+def main() -> None:
+    """ Ksft boiler plate main """
+
+    with NetDrvEpEnv(__file__) as cfg:
+        ksft_run(cases=[test], args=(cfg, ))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()
-- 
2.34.1

Re: [PATCH net-next v2 2/3] selftests: drv-net: Check the features set by set_ethtool_feat()

[Nicolai Buchwitz]

Hi Ovidiu

On 18.9.2026 13:25, Ovidiu Panait wrote:
> Read back the features after running ethtool -K to check if they were
> actually applied. The drivers might refuse to set a feature silently 
> and
> the test could run with a different configuration than the requested 
> one.
> 
> Add a 'check' parameter to skip this, as the GRO "hw" mode handles the
> case where HW GRO is cleared by the driver.
> 
> Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
> ---

> [...]

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai

Re: [PATCH net-next v2 3/3] selftests: drv-net: Add VLAN test

[Nicolai Buchwitz]

Hi Ovidiu

On 18.9.2026 13:25, Ovidiu Panait wrote:
> Add a test that validates ping traffic over VLAN interfaces. It aims
> to catch drivers which mishandle hardware VLAN tag stripping, in
> particular QinQ.
> 
> Three VLAN configurations are covered, each with hardware RX VLAN
> stripping enabled and disabled (via the rx-vlan-offload and
> rx-vlan-stag-hw-parse features):
> - a single 802.1q VLAN interface
> - a single 802.1ad VLAN interface
> - an 802.1q VLAN stacked on top of an 802.1ad interface
> 
> The "hw" test variants enable the RX VLAN stripping features supported
> by the device (rx-vlan-offload and rx-vlan-stag-hw-parse), the "sw"
> test variants disable all of them. A test is xfailed if the requested
> configuration is not possible.
> 
> VLAN insertion offloads are not tested for now.
> 
> NETIF=end0 LOCAL_V4=172.16.0.2 REMOTE_V4=172.16.0.3 \
> REMOTE_TYPE=ssh REMOTE_ARGS=root@172.16.0.3 \
> run_kselftest.sh -t drivers/net/hw:vlan.py
>  TAP version 13
>  1..1
>  # timeout set to 0
>  # selftests: drivers/net/hw: vlan.py
>  # # Interface: end0, driver: st_gmac
>  # TAP version 13
>  # 1..6
>  # ok 1 vlan.test.8021q_hw
>  # ok 2 vlan.test.8021q_sw
>  # ok 3 vlan.test.8021ad_hw
>  # ok 4 vlan.test.8021ad_sw
>  # ok 5 vlan.test.qinq_hw
>  # ok 6 vlan.test.qinq_sw
>  # # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0
>  ok 1 selftests: drivers/net/hw: vlan.py
>  # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
> 
> Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
> ---

> [...]

> +LOCAL_IP = os.environ.get("VLAN_LOCAL_V4", "198.51.100.1")
> +REMOTE_IP = os.environ.get("VLAN_REMOTE_V4", "198.51.100.2")

   LOCAL_IP = "198.51.100.1"
   REMOTE_IP = "198.51.100.2"

IMHO it would be better to use cfg.env, so net.config is honoured.

Either way the vars (eg. VLAN_LOCAL_V4 / VLAN_REMOVE_V4) should be
mentioned in README.rst? Right now it is only stated in the v2 changelog
in this commit.

> +
> +
> +def _vlan_add(base, name, proto, vid, host=None):
> +    """Create a VLAN device on top of base and bring it up."""
> +
> +    ip(f"link add link {base} name {name} type vlan proto {proto} id 
> {vid}",
> +       host=host)
> +    defer(ip, f"link del {name}", host=host)
> +    ip(f"link set {name} up", host=host)
> +
> +
> +def _vlan_setup(base, addr, outer_proto, inner_proto, host=None):
> +    """Create VLAN interfaces on base and set an IP on the innermost 
> one."""
> +
> +    _vlan_add(base, OUTER_DEV, outer_proto, OUTER_VID, host=host)
> +    if inner_proto:
> +        _vlan_add(OUTER_DEV, INNER_DEV, inner_proto, INNER_VID, 
> host=host)
> +
> +    dev = INNER_DEV if inner_proto else OUTER_DEV
> +    ip(f"addr add {addr}/24 dev {dev}", host=host)
> +
> +
> +def _setup(cfg, outer_proto, inner_proto, hw_strip):
> +    """Configure VLAN stripping and create the VLAN interfaces."""
> +
> +    names = ["rx-vlan-offload"]
> +    if outer_proto == "802.1ad":
> +        names.append("rx-vlan-stag-hw-parse")
> +
> +    feat = ethtool(f"-k {cfg.ifname}", json=True)[0]
> +    feats = {}
> +    for name in names:
> +        # hw: skip the features the device does not support
> +        # sw: request all of them off
> +        if hw_strip and feat[name]["fixed"] and not 
> feat[name]["active"]:
> +            continue
> +        feats[name] = hw_strip
> +
> +    if hw_strip and not feats:
> +        raise KsftXfailEx("Device does not support RX VLAN stripping")
> +
> +    set_ethtool_feat(cfg.ifname, feat, feats)
> +
> +    _vlan_setup(cfg.ifname, LOCAL_IP, outer_proto, inner_proto)
> +    _vlan_setup(cfg.remote_ifname, REMOTE_IP, outer_proto, 
> inner_proto,

LOCAL_IP -> cfg.local_ip
REMOTE_IP -> cfg.remote_ip

> +                host=cfg.remote)
> +
> +
> +def _vlan_variants():
> +    """Generator that yields the VLAN protocols and the stripping 
> mode."""
> +
> +    yield KsftNamedVariant("8021q_hw", "802.1q", None, True)
> +    yield KsftNamedVariant("8021q_sw", "802.1q", None, False)
> +    yield KsftNamedVariant("8021ad_hw", "802.1ad", None, True)
> +    yield KsftNamedVariant("8021ad_sw", "802.1ad", None, False)
> +    yield KsftNamedVariant("qinq_hw", "802.1ad", "802.1q", True)
> +    yield KsftNamedVariant("qinq_sw", "802.1ad", "802.1q", False)
> +
> +
> +@ksft_variants(_vlan_variants())
> +def test(cfg, outer_proto, inner_proto, hw_strip):
> +    """Run a single VLAN test"""
> +
> +    _setup(cfg, outer_proto, inner_proto, hw_strip)
> +
> +    cmd(f"ping -c 1 -W 5 {REMOTE_IP}")

REMOTE_IP -> cfg.remote_ip

> +
> +
> +def main() -> None:
> +    """ Ksft boiler plate main """
> +
> +    with NetDrvEpEnv(__file__) as cfg:

cfg.local_ip = cfg.env.get("VLAN_LOCAL_V4", LOCAL_IP)
cfg.remote_ip = cfg.env.get("VLAN_REMOTE_V4", REMOTE_IP)

> +        ksft_run(cases=[test], args=(cfg, ))
> +    ksft_exit()
> +
> +
> +if __name__ == "__main__":
> +    main()

Thanks,
Nicolai

Re: [PATCH net-next v2 3/3] selftests: drv-net: Add VLAN test

[Jakub Kicinski]

On Fri, 18 Sep 2026 14:04:13 +0200 Nicolai Buchwitz wrote:
> > +LOCAL_IP = os.environ.get("VLAN_LOCAL_V4", "198.51.100.1")
> > +REMOTE_IP = os.environ.get("VLAN_REMOTE_V4", "198.51.100.2")  
> 
>    LOCAL_IP = "198.51.100.1"
>    REMOTE_IP = "198.51.100.2"

LOCAL_IP / REMOTE_IP are in the default network segment (vlan 0)
Here we need some "unused" IP subnet that we can assign without
conflicts. Getting it from the config would indeed be good, but
since this is the first use perhaps we should defer until it actually
bothers someone?

Or am I missing something?