Re: [PATCH net-next v4 2/3] virtio_net: add optional flow dissection in virtio_net_hdr_to_skb

On Wed, Jun 9, 2021 at 8:53 PM Jason Wang [off-list ref] wrote:

It works but it couples virtio with bpf.

Jason,

I think your main concern is that it makes virtio_net_hdr into uapi?
That's not the case. __sk_buff is uapi, but pointers to sockets
and other kernel data structures are not.
Yes. It's a bit weird that uapi struct has a pointer to kernel internal,
but I don't see it as a deal breaker.
Tracing progs have plenty of such cases.
In networking there is tcp-bpf where everything is kernel internal and non-uapi.
So after this patch virtio_net_hdr is free to change without worrying about bpf
progs reading it.