On Fri, Mar 31, 2023 at 03:20:35PM +0800, Xuan Zhuo wrote:
> On Thu, 30 Mar 2023 12:48:22 +0200, Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
> > On Tue, 2023-03-28 at 20:04 +0800, Xuan Zhuo wrote:
> > > @@ -949,15 +1042,11 @@ static struct sk_buff *receive_small(struct net_device *dev,
> > > {
> > > struct sk_buff *skb;
> > > struct bpf_prog *xdp_prog;
> > > - unsigned int xdp_headroom = (unsigned long)ctx;
> > > - unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
> > > + unsigned int header_offset = VIRTNET_RX_PAD;
> > > unsigned int headroom = vi->hdr_len + header_offset;
> >
> > This changes (reduces) the headroom for non-xpd-pass skbs.
> >
> > [...]
> > > + buf += header_offset;
> > > + memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> >
> > AFAICS, that also means that receive_small(), for such packets, will
> > look for the virtio header in a different location. Is that expected?
>
>
> That is a mistake.
>
> Will fix.
>
> Thanks.
Do try to test small and big packet configurations though, too.
> >
> > Thanks.
> >
> > Paolo
> >
