Re: [PATCH net-next v2] gve: add XDP metadata support for DQ RDA

[Joshua Washington]

On Fri, Mar 20, 2026 at 6:55 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Wed, 18 Mar 2026 12:24:50 -0700 Joshua Washington wrote:
> > Commit 1b42e07af1ee ("gve: Add Rx HWTS metadata to AF_XDP ZC mode")
> > exposes support for the XDP RX timestamping metadata operation in the DQ
> > RDA mode. While the operation works on its own, the intent was to enable
> > XDP metadata support for the queue format as a whole along with it.
> > Currently bfp_xdp_adjust_meta fails because meta_valid is set to false.
>
> bfp -> bpf

Will make this change in V3.

>
> > This change updates xdp_buff preparation to set meta_valid to true, so
> > metadata can be fully used by XDP programs.
> >
> > Reviewed-by: Harshitha Ramamurthy <hramamurthy@xxxxxxxxxx>
> > Reviewed-by: Jordan Rhee <jordanrhee@xxxxxxxxxx>
> > Signed-off-by: Joshua Washington <joshwash@xxxxxxxxxx>
> > ---
> >  drivers/net/ethernet/google/gve/gve_rx_dqo.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/google/gve/gve_rx_dqo.c b/drivers/net/ethernet/google/gve/gve_rx_dqo.c
> > index 7924dce719e2..48945b4b6766 100644
> > --- a/drivers/net/ethernet/google/gve/gve_rx_dqo.c
> > +++ b/drivers/net/ethernet/google/gve/gve_rx_dqo.c
> > @@ -877,7 +877,7 @@ static int gve_rx_dqo(struct napi_struct *napi, struct gve_rx_ring *rx,
> >                                buf_state->page_info.page_address +
> >                                buf_state->page_info.page_offset,
> >                                buf_state->page_info.pad,
> > -                              buf_len, false);
> > +                              buf_len, true);
> >               gve_xdp.gve = priv;
> >               gve_xdp.compl_desc = compl_desc;
> >
>
> AI says:
>
> While this allows XDP programs to write custom metadata via
> bpf_xdp_adjust_meta(), does the driver correctly propagate this metadata
> to the SKB after XDP_PASS?
>
> https://sashiko.dev/#/patchset/20260318192450.3400774-1-joshwash%40google.com
> --
> pw-bot: cr

Thanks for bringing this to my attention. I'll introduce a new patch
updating the XDP_PASS paths to make use of `xdp_build_skb` kernel
methods, which should handle metadata implicitly. Besides
commonization, this also removes an extra copy in the XDP_PASS case
for copy mode XDP.