[PATCH v9 0/2] virtio-net: define UDP tunnel offload

[Paolo Abeni <pabeni@redhat.com>]

UDP tunnel usage is ubiquitous in container deployment, and the ability
to offload UDP encapsulated GSO traffic impacts greatly the performances
and the CPU utilization of such use cases.

This series introduces separate features to handle both UDP tunnel 
segmentation offload (patch 1) and UDP tunnel outer checksum offload
(patch 2).

This revision is hopefully a minor delta over the previous iteration,
covering a few problems spotted thanks to the PoC implementation
available here:

https://github.com/pabeni/linux-devel/commits/virtio_tunnel_gso/
https://github.com/pabeni/qemu/commits/virtio_tunnel/

Changes from v8:
- rebased on top of virtio-1.4, changed udp-tunnel features number
  to avoid conflicts/duplications
- Clarified the usage of DATA_VALID flag with UDP tunneled GSO packets
- mandate strict hdr validation on the rx side, too - for UDP tunneled
  GSO packets only

Changes from v7:
- minor cleanup in patch 1/2
- dropped confusing wording about csum validation in patch 2/2

Changes from v6:
- replaced inner_protocol_type with
  VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV{4,6}
- many clarifications and cleanup, see the individual patches changelog
  for the details

Changes from v5:
- split in 2 patches
- dropped outer_mh_offset field
- many csum related clarification
---
Note that such while the mentioned PoC is based on the previous
iteration of this change, it already deals with all the delta introduced
here except the refined DATA_VALID handling. I'll try to update the PoC
WRT that ASAP.

Paolo Abeni (2):
  virtio-net: define UDP tunnel segmentation offload feature
  virtio-net: define UDP tunnel checksum offload feature

 device-types/net/description.tex | 325 ++++++++++++++++++++++++++++++-
 1 file changed, 315 insertions(+), 10 deletions(-)

-- 
2.45.2