Re: [PATCH net-next V4 14/14] selftests: drv-net: Add PSP HW GRO conformance tests

On Tue, 2026-09-08 at 19:22 -0400, Daniel Zahka wrote:

On Tue Sep 8, 2026 at 2:52 AM EDT, Tariq Toukan wrote:

quoted

From: Cosmin Ratiu <redacted>

Add PSP conformance tests using the same gro helper binary as other
gro
tests , but in --psp mode. SPIs are procured by psp_gro.py from a
real
PSP device and handed off to the gro sender & receiver. The sender
crafts and encrypts packets in software, the receiver relies fully
on
the HW to decrypt, decapsulate and do HW GRO.

Because the NIC decrypts and decapsulates before the frames reach
the
receiver AF_PACKET tap, the gro receiver sees the plain frames and
the
assertions remain exactly the same as other gro tests.

So these tests verify, at length, that the device does PSP HW-GRO
the
same way as plain TCP.

Additional PSP-specific tests are defined to check that GRO doesn't
merge packets across PSP versions, SPIs, encryption-status, etc.

Some gro tests are not included because they don't work:
- ip_csum: the checksum is recomputed by psp_dev_rcv().

psp_dev_rcv() isn't on the hw gro path for mlx5, right?

You're right, that's a bogus argument, sorry.
The truth was that the encap support in gro.c was recomputing the IP
checksum, sabotaging the bad csum test... Will be fixed in the next
version.

quoted

- tcp_csum: packets are marked with CHECKSUM_UNNECESSARY.

this also seems strange to me as the hw gro engine and its decision
to
coalesce two packets sits upstream of this skb->ip_summed
determination
in the driver, right?

Another weak argument from my side, sorry. I will add the test back.

quoted

- ip_frag4/ip_frag6: PSP is incompatible with IP fragmentation.
- IPv6 extension header tests: PSP doesn't deal with IPv6 ext
headers.

Signed-off-by: Cosmin Ratiu <redacted>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---

...

quoted

+
+@ksft_variants(_ip_variants())
+def test_psp_ver_diff(cfg, protocol):
+    """Frames from two different PSP versions must not
coalesce."""
+    init_psp_dev(cfg)
+    if len(cfg.psp_info['psp-versions-cap']) < 2:

nit: what the above checks is slightly different than what the _run()
below uses, e.g. dev supports versions 0 and 2.

Will drop this check.

quoted

+        raise KsftSkipEx("Device supports a single PSP version")
+
+    _run(cfg, "psp_ver_diff", protocol, [0, 1])
+

couple of minor comments:

Reviewed-by: Daniel Zahka <daniel.zahka@gmail.com>

Thank you for the review!

Cosmin.