>
>
> Lorenzo Bianconi <lorenzo@xxxxxxxxxx> writes:
>
> > Introduce __xdp_build_skb_from_frame and
> > xdp_build_skb_from_frame
> > utility routines to build the skb from xdp_frame.
> > Add xdp multi-buff support to cpumap
> >
> > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> > ---
> > include/net/xdp.h | 5 ++++
> > kernel/bpf/cpumap.c | 45 +---------------------------
> > net/core/xdp.c | 73
> > +++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 79 insertions(+), 44 deletions(-)
> >
> [...]
> > diff --git a/net/core/xdp.c b/net/core/xdp.c
> > index 6c8e743ad03a..55f3e9c69427 100644
> > --- a/net/core/xdp.c
> > +++ b/net/core/xdp.c
> > @@ -597,3 +597,76 @@ void xdp_warn(const char *msg, const char
> > *func, const int line)
> > WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg);
> > };
> > EXPORT_SYMBOL_GPL(xdp_warn);
> > +
> > +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame
> > *xdpf,
> > + struct sk_buff *skb,
> > + struct net_device *dev)
> > +{
> > + unsigned int headroom = sizeof(*xdpf) + xdpf->headroom;
> > + void *hard_start = xdpf->data - headroom;
> > + skb_frag_t frag_list[MAX_SKB_FRAGS];
> > + struct xdp_shared_info *xdp_sinfo;
> > + int i, num_frags = 0;
> > +
> > + xdp_sinfo = xdp_get_shared_info_from_frame(xdpf);
> > + if (unlikely(xdpf->mb)) {
> > + num_frags = xdp_sinfo->nr_frags;
> > + memcpy(frag_list, xdp_sinfo->frags,
> > + sizeof(skb_frag_t) * num_frags);
> > + }
>
> nit, can you please move the xdp_sinfo assignment inside this 'if'
> ? This would help to emphasize that regarding xdp_frame tailroom
> as xdp_shared_info struct (rather than skb_shared_info) is correct
> only when the mb bit is set
>
> thanks,
> Shay
ack, will do in v6.
Regards,
Lorenzo
>
> > +
> > + skb = build_skb_around(skb, hard_start, xdpf->frame_sz);
> > + if (unlikely(!skb))
> > + return NULL;
> [...]
>
