On Sat, Jul 16, 2016 at 5:05 PM, Jesse Gross <je...@kernel.org> wrote:
> On Tue, Jul 12, 2016 at 10:26 PM, Pravin B Shelar <pshe...@ovn.org> wrote:
>> Upstream commit:
>> commit fe3a5f6c795810edb1646a840fec3c8c350c2a4e
>> Author: Simon Horman <simon.hor...@netronome.com>
>>
>> openvswitch: allow output of MPLS packets on tunnel vports
>>
>> Currently output of MPLS packets on tunnel vports is not allowed by Open
>> vSwitch. This is because historically encapsulation was done in such a
>> way
>> that the inner_protocol field of the skb needed to hold the inner
>> protocol
>> for both MPLS and tunnel encapsulation in order for GSO segmentation to
>> be
>> performed correctly.
>>
>> Since b2acd1dc3949 ("openvswitch: Use regular GRE net_device instead of
>> vport") Open vSwitch makes use of lwt to output to tunnel netdevs which
>> perform encapsulation. As no drivers expose support for MPLS offloads
>> this
>> means that GSO packets are segmented in software by validate_xmit_skb(),
>> which is called from __dev_queue_xmit(), before tunnel encapsulation
>> occurs.
>> This means that the inner protocol of MPLS is no longer needed by the
>> time
>> encapsulation occurs and the contention on the inner_protocol field of
>> the
>> skb no longer occurs.
>>
>> Thus it is now safe to output MPLS to tunnel vports.
>>
>> Signed-off-by: Simon Horman <simon.hor...@netronome.com>
>> Reviewed-by: Jesse Gross <je...@kernel.org>
>> Signed-off-by: David S. Miller <da...@davemloft.net>
>>
>> Signed-off-by: Pravin B Shelar <pshe...@ovn.org>
>
> I don't know if this is safe on our backported kernel module. The
> premise of this commit was that packets coming out of OVS will go
> through the device layer before they hit the tunnel code and that will
> resolve any offloads and use of inner_protocol. However, with our
> versions of lightweight tunnels, this doesn't happen.
right, Lets skip this check if we are using upstream tunneling
modules. I will post update patch.
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
