Hi Jason, On Wed, Aug 13, 2025 at 6:30 PM Paolo Abeni <pab...@redhat.com> wrote: > Some virtualized deployments use UDP tunnel pervasively and are impacted > negatively by the lack of GSO support for such kind of traffic in the > virtual NIC driver. > > The virtio_net specification recently introduced support for GSO over > UDP tunnel, and the kernel side of the implementation has been merged > into the net-next tree; this series updates the virtio implementation to > support such a feature. > > Currently the qemu virtio support limits the feature space to 64 bits, > while the virtio specification allows for a larger number of features. > Specifically the GSO-over-UDP-tunnel-related virtio features use bits > 65-69; the larger part of this series (patches 4-12) actually deals with > extending the features space. > > The extended features are carried by fixed size uint64_t arrays, > bringing the current maximum features number to 128. > > The patches use some syntactic sugar to try to minimize the otherwise > very large code churn. Specifically the extended features are boundled > in an union with 'legacy' features definition, allowing no changes in > the virtio devices not needing the extended features set. > > The actual offload implementation is in patches 13 and 14 and boils down > to propagating the new offload to the tun devices and the vhost backend. > > Patch 1 is a small pre-req refactor that ideally could enter the > tree separately; it's presented here in the same series to help > reviewers more easily getting the full picture, patch 2 updates to > linux headers update script to deal with annotations recently introduce > in the kernel and patch 3 is a needed linux headers update. > > Tested with basic stream transfer with all the possible permutations of > host kernel/qemu/guest kernel with/without GSO over UDP tunnel support, > vs snapshots creation and restore and vs migration. > > The new features are disabled by default to avoid compatibilty issues. > They could be enabled after that hw_compat_10_1 will be added, together > with the related compatiblity entries. > > Based-on: > 9d71108d7de139dd4f4e6efe6837cabb32bf5616.1755078918.git.pab...@redhat.com
I'm wondering you could have a look at this series and its pre-req: https://lists.gnu.org/archive/html/qemu-devel/2025-08/msg02004.html Thanks, Paolo
