Re: [PATCH bpf-next v2 0/3] XDP metadata: Rx checksum/GSO hint; Tx GSO offload

[Willem de Bruijn]

Stanislav Fomichev wrote:
> On 10/18, Muyang Tian wrote:
> > This series introduce XDP metadata functionality, including Rx checksum/GSO hint
> > and Tx GSO offload. This is aimed to transfer control fields when processing jumbo
> > frames between VMs.
> 
> Ideally, the series should also have the implementation of these hints
> for a couple of devices and appropriate selftest updates to exercise
> them.

+1

> For GSO, CC Willem going forward (I don't think I understand why
> we want to have gso_type in the TX hint; something like header_len
> seems like a better fit).

GSO on Tx makes sense. To be able to program hardware USO, say.

GSO on Rx is less obvious. Is this for HW-GRO? In general, some usage
context will be helpful.

Two implementation questions:

- why define an XDP specific type for checksum types, but reuse the
  netdev type for gso_type?
- why u32 gso_type, when it is a u8 in skb_shared_info?

> Please also don't post v3 yet and allow at least a week for the initial
> reviewers to catch up..