Re: [PATCH net-next v3 4/4] net: ntb_netdev: Preserve CHECKSUM_PARTIAL across NTB

[Koichiro Den]

On Thu, Sep 10, 2026 at 05:20:47PM -0700, Jakub Kicinski wrote:
> On Fri,  4 Sep 2026 14:21:34 +0900 Koichiro Den wrote:
> > Calculating L4 checksums can limit ntb_netdev throughput especially on
> > embedded systems, where CPU resources are often limited. A trusted PCIe
> > fabric can avoid that work.
> 
> Would it make more sense to prepend something like a virtio_net_hdr
> to the data so you can cheaply express more offloads?

Thanks for the suggestion. Yes, packing offload metadata into
ntb_payload_header::flags could become limiting in the future. We could prepend
a header like virtio_net_hdr to each packet and use one metadata bit to indicate
its presence.
(BTW, GSO hasn't been the focus here, given the large MTUs NTB can support, but
leaving room for it makes sense.)

Best regards,
Koichiro