Subject: Re: [PATCH net v2] net: drop bad gso csum_start and offset in virtio_net_hdr

From: Sudeep Holla <[email-masked]>
Date: Mon, 9 Sep 2024 16:14:47 +0100

On Mon, Sep 09, 2024 at 12:14:28PM +0100, Mark Brown wrote:
> On Mon, Sep 09, 2024 at 11:45:27AM +0200, Szabolcs Nagy wrote:
> 
> > fvp is closed source but has freely available binaries
> > for x86_64 glibc based linux systems (behind registration
> > and license agreements) so in principle the issue can be
> > reproduced outside of arm but using fvp is not obvious.
> 
> > hopefully somebody at arm can pick it up or at least
> > report this thread to the fvp team internally.
> 
> FWIW there's a tool called shrinkwrap which makes it quite a lot easier
> to get going:
> 
>    https://gitlab.arm.com/tooling/shrinkwrap
> 
> though since the models are very flexibile valid configurations that
> people see issues with aren't always covered by shrinkwrap.

It is fairly trivial to change the default config and use virtio-net to
reproduce this issue. If anyone tries the above tool, they can apply below
diff and should be able to reproduce the issue.

--
Regards,
Sudeep

diff --git i/config/FVP_Base_RevC-2xAEMvA-base.yaml w/config/FVP_Base_RevC-2xAEMvA-base.yaml
index 86d8cf9cb0f8..9951c5a948bb 100644
--- i/config/FVP_Base_RevC-2xAEMvA-base.yaml
+++ w/config/FVP_Base_RevC-2xAEMvA-base.yaml
@@ -39,8 +39,10 @@ description: >-
     # Networking. By default use user-space networking, mapping port 22 in the
     # FVP to a user-specified port on the host (see rtvar:LOCAL_NET_PORT). This
     # enables ssh.
-    -C bp.smsc_91c111.enabled: 1
-    -C bp.hostbridge.userNetworking: 1
+    -C bp.smsc_91c111.enabled: 0
+    -C bp.hostbridge.userNetworking: 0
+    -C bp.virtio_net.enabled: 1
+    -C bp.virtio_net.hostbridge.userNetworking: 1
     -C bp.hostbridge.userNetPorts: ${rtvar:LOCAL_NET_PORT}=22

     # FVP Performance tweaks.