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.
>
> Thanks.
>
> Paolo
>
