The userdata payload is rebuilt and republished on every configfs write,
including while the target is enabled and messages are being sent.

Add netcons_userdata.sh that runs random tests with userdata.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Link: https://patch.msgid.link/20260810-netcons-userdata-rcu-v3-2-f65557f769ce@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The blamed commit updated a tc replace command by adding a handle.

  -    tc(f"qdisc replace dev {ifname} root {qdisc} {optargs}")
  +    tc(f"qdisc replace dev {ifname} root handle 1: {qdisc} {optargs}")

This breaks the test if the root qdisc already has that handle and is of
different kind, with

  "Invalid qdisc name: must match existing qdisc."

If no handle is asked, or the kind differs, tc replace removes the old
qdisc and grafts a new one.

If a handle is asked and exists, tc replace tries to change the qdisc
in place, for which the kind must be the same.

It does not trigger in all setups, like netdevsim or debian 13, which
do not have root handle 1:. But it is a common root handle.

Solve the bug by first deleting the existing root qdisc if one exists.

Wrap that command in a try block, because it will fail for default
qdiscs with handle 0: with

  "Error: Cannot delete qdisc with handle of zero."

Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20260810183118.32d5c06a@kernel.org/
Fixes: ef3d6cca02c8 ("selftests: drv-net: so_txtime: only send test traffic to sch_etf")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260811182856.2702163-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The devlink port_split test has limited applicability.
NICs (as opposed to switches) require at least a re-probe
to apply the split configuration.

On top of that the test is not compatible with our driver env,
it just splits all ports on the system, not only what NETIF
points at.

Long term we may want to add some indication in devlink whether
the port splitting is runtime (cmode of sorts), and fix the
test to follow driver env. But since no (known) NIC driver can
support runtime anyway let's just hide the test from the selftest
framework by moving it to extra files.

Having this test randomly break unrelated NICs within the DUT
makes people implement allow-lists for ksft, which then means
their setups don't run new tests. It's very useful during test
review to see whether the test works across all the runners.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20260811004645.1072124-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bond_reset() waits up to 2 seconds for IPv6 connectivity.
With default settings DAD itself may take almost 2 seconds,
causing flakes on debug builds. It used to flake once or
twice a week, recently it started failing once a day.
Probably some downstream changes to scheduler, or our machines
go busier.

A lot of selftests already use nodad, let's use nodad in bonding, too.
I don't see an obvious reason why DAD would be important to the test.

Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn>
Link: https://patch.msgid.link/20260808162345.2442594-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The ETF qdiscs drops traffic without a socket or txtime. Even with
parameter skip_sock_check regular traffic is affected by ETF.

This test ran fine when run manually in a pure software environment.
But with drv-net across two hosts tests fail as early as when calling
cfg.remote.deploy due to effectively losing connectivity.

Isolate the intended test traffic:
- mark that with SO_MARK 100
- install a regular permissive root prio qdisc for background traffic
- install the ETF qdisc as leaf
- install a filter that only directs SO_MARK 100 traffic to this leaf

Technically other high prio traffic will map onto this leaf based on
ToS band mapping too. But that is immaterial in practice.

Fixes: 5c6baef3885c ("selftests: drv-net: convert so_txtime to drv-net")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260808160129.890119-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Some devices refresh the statistics exposed via ethtool only
periodically, every stats-block-usecs (as reported by ethtool -c).
ethtool_std_stats and ethtool_rmon sample the counters immediately
after generating traffic, so on such devices they can read stale
values and fail with a delta short of the packets just sent.

Add a hw_stats_settle() helper which sleeps for 1.25x the configured
stats-block-usecs (defaulting to 20ms when the device reports no, or
a zero, period). Use it for ethtool std stats and RMON.
The 1.25x/20msec heuristic matches what the Python tests do.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20260808163653.2460381-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mausezahn defaults to sending packets back to back at the maximum rate,
which can cause packet loss, especially if receiver is running a debug
kernel. Space the generated packets out (-d 10usec), like ethtool_rmon
already does.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20260808163653.2460381-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The adaptive-rx and adaptive-tx checks use 'ethtool -c | grep -q' under
'set -o pipefail'. grep -q exits as soon as it finds a match, which can
happen before ethtool finishes writing its output. When that occurs,
ethtool receives SIGPIPE causing (uninformative):

 # selftests: drivers/net/netdevsim: ethtool-coalesce.sh
 # FAILED 1/22 checks
 not ok 1 selftests: drivers/net/netdevsim: ethtool-coalesce.sh # exit=1

This happens on debug kernels in NIPA, ~4% of the time.

Link: https://patch.msgid.link/20260808163416.2456810-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add a new devmem test case for binding the dmabuf with rx-page-size=16K.
The test sweeps RX payload sizes straddling the niov boundary to cover
the sub-niov, exact-niov, and multi-niov RX paths.

Silence pylint invalid-name (`with open() as f`) and too-many-arguments
(ncdevmem_rx grew to 6 args) at file scope.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260805-tcpdm-large-niovs-v8-3-3e0225e2808c@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add -b <bytes> to request a non-default niov size via
NETDEV_A_DMABUF_RX_PAGE_SIZE. When the value exceeds PAGE_SIZE,
udmabuf_alloc() switches to an MFD_HUGETLB-backed memfd so each 2 MB
hugepage produces one naturally-aligned sg entry.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260805-tcpdm-large-niovs-v8-2-3e0225e2808c@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>