Subject: Re: mlx4+vxlan offload breaks gre tunnels

From: Florian Westphal <[email-masked]>
Date: Wed, 5 Nov 2014 17:53:51 +0100

Or Gerlitz <[email-masked]> wrote:
> On 11/5/2014 5:04 PM, Florian Westphal wrote:
> >tl,dr: all tcp packets sent via gre tunnel have broken tcp csum if vxlan offload
> >is enabled with mlx4 driver.
> >
> Yep, I can see now the problem. It comes into play with
> ConnectX3-pro NICs that support VXLAN offloads (but not with
> ConnectX3 NIC which don't) when you enable the offloads support on
> the CX3-pro.

[..]
> I think the best effort we can do now is
> 
> 1. come up with something such as the below patch for 3.18 which is
> back-ward portable for -stable kernels, it will only arm the hw
> offloads if the OS tells us there's VXLAN in action
> 
[..]
> 
> tested to work with the  following which is a bit different, tell me
> if it works for you

Right, the patch below works in my setup as well (until link-add-vxlan,
that is ;) )

Thanks,
Florian