Re: [PATCH v4 0/6] TUN/VirtioNet USO features support.

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Dec 01, 2022 at 11:56:38PM +0200, Andrew Melnychenko wrote:
> Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6.
> Technically they enable NETIF_F_GSO_UDP_L4
> (and only if USO4 & USO6 are set simultaneously).
> It allows the transmission of large UDP packets.
> 
> UDP Segmentation Offload (USO/GSO_UDP_L4) - ability to split UDP packets
> into several segments. It's similar to UFO, except it doesn't use IP
> fragmentation. The drivers may push big packets and the NIC will split
> them(or assemble them in case of receive), but in the case of VirtioNet
> we just pass big UDP to the host. So we are freeing the driver from doing
> the unnecessary job of splitting. The same thing for several guests
> on one host, we can pass big packets between guests.
> 
> Different features USO4 and USO6 are required for qemu where Windows
> guests can enable disable USO receives for IPv4 and IPv6 separately.
> On the other side, Linux can't really differentiate USO4 and USO6, for now.
> For now, to enable USO for TUN it requires enabling USO4 and USO6 together.
> In the future, there would be a mechanism to control UDP_L4 GSO separately.
> 
> New types for virtio-net already in virtio-net specification:
> https://github.com/oasis-tcs/virtio-spec/issues/120
> 
> Test it WIP Qemu https://github.com/daynix/qemu/tree/USOv3
> 
> Andrew (5):
>   uapi/linux/if_tun.h: Added new offload types for USO4/6.
>   driver/net/tun: Added features for USO.
>   uapi/linux/virtio_net.h: Added USO types.
>   linux/virtio_net.h: Support USO offload in vnet header.
>   drivers/net/virtio_net.c: Added USO support.
> 
> Andrew Melnychenko (1):
>   udp: allow header check for dodgy GSO_UDP_L4 packets.

I don't see patches except 0 on list.

>  drivers/net/tap.c               | 10 ++++++++--
>  drivers/net/tun.c               |  8 +++++++-
>  drivers/net/virtio_net.c        | 24 +++++++++++++++++++++---
>  include/linux/virtio_net.h      |  9 +++++++++
>  include/uapi/linux/if_tun.h     |  2 ++
>  include/uapi/linux/virtio_net.h |  5 +++++
>  net/ipv4/udp_offload.c          |  3 ++-
>  net/ipv6/udp_offload.c          |  3 ++-
>  8 files changed, 56 insertions(+), 8 deletions(-)
> 
> -- 
> 2.38.1
> 
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