On Tue, Feb 25, 2020 at 12:32:12PM +0900, Yuya Kusakabe wrote: > Implement support for transferring XDP meta data into skb for > virtio_net driver; before calling into the program, xdp.data_meta points > to xdp.data, where on program return with pass verdict, we call > into skb_metadata_set(). > > Tested with the script at > https://github.com/higebu/virtio_net-xdp-metadata-test. > > Signed-off-by: Yuya Kusakabe <yuya.kusakabe@xxxxxxxxx> > --- Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > drivers/net/virtio_net.c | 52 ++++++++++++++++++++++++---------------- > 1 file changed, 32 insertions(+), 20 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index f39d0218bdaa..12d115ef5e74 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -371,7 +371,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > struct receive_queue *rq, > struct page *page, unsigned int offset, > unsigned int len, unsigned int truesize, > - bool hdr_valid) > + bool hdr_valid, unsigned int metasize) > { > struct sk_buff *skb; > struct virtio_net_hdr_mrg_rxbuf *hdr; > @@ -393,6 +393,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > else > hdr_padded_len = sizeof(struct padded_vnet_hdr); > > + /* hdr_valid means no XDP, so we can copy the vnet header */ > if (hdr_valid) > memcpy(hdr, p, hdr_len); > > @@ -405,6 +406,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > copy = skb_tailroom(skb); > skb_put_data(skb, p, copy); > > + if (metasize) { > + __skb_pull(skb, metasize); > + skb_metadata_set(skb, metasize); > + } > + > len -= copy; > offset += copy; > > @@ -450,10 +456,6 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi, > struct virtio_net_hdr_mrg_rxbuf *hdr; > int err; > > - /* virtqueue want to use data area in-front of packet */ > - if (unlikely(xdpf->metasize > 0)) > - return -EOPNOTSUPP; > - > if (unlikely(xdpf->headroom < vi->hdr_len)) > return -EOVERFLOW; > > @@ -644,6 +646,7 @@ static struct sk_buff *receive_small(struct net_device *dev, > unsigned int delta = 0; > struct page *xdp_page; > int err; > + unsigned int metasize = 0; > > len -= vi->hdr_len; > stats->bytes += len; > @@ -683,8 +686,8 @@ static struct sk_buff *receive_small(struct net_device *dev, > > xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len; > xdp.data = xdp.data_hard_start + xdp_headroom; > - xdp_set_data_meta_invalid(&xdp); > xdp.data_end = xdp.data + len; > + xdp.data_meta = xdp.data; > xdp.rxq = &rq->xdp_rxq; > orig_data = xdp.data; > act = bpf_prog_run_xdp(xdp_prog, &xdp); > @@ -695,6 +698,7 @@ static struct sk_buff *receive_small(struct net_device *dev, > /* Recalculate length in case bpf program changed it */ > delta = orig_data - xdp.data; > len = xdp.data_end - xdp.data; > + metasize = xdp.data - xdp.data_meta; > break; > case XDP_TX: > stats->xdp_tx++; > @@ -740,6 +744,9 @@ static struct sk_buff *receive_small(struct net_device *dev, > memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); > } /* keep zeroed vnet hdr since XDP is loaded */ > > + if (metasize) > + skb_metadata_set(skb, metasize); > + > err: > return skb; > > @@ -760,8 +767,8 @@ static struct sk_buff *receive_big(struct net_device *dev, > struct virtnet_rq_stats *stats) > { > struct page *page = buf; > - struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, > - PAGE_SIZE, true); > + struct sk_buff *skb = > + page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0); > > stats->bytes += len - vi->hdr_len; > if (unlikely(!skb)) > @@ -793,6 +800,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > unsigned int truesize; > unsigned int headroom = mergeable_ctx_to_headroom(ctx); > int err; > + unsigned int metasize = 0; > > head_skb = NULL; > stats->bytes += len - vi->hdr_len; > @@ -839,8 +847,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > data = page_address(xdp_page) + offset; > xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len; > xdp.data = data + vi->hdr_len; > - xdp_set_data_meta_invalid(&xdp); > xdp.data_end = xdp.data + (len - vi->hdr_len); > + xdp.data_meta = xdp.data; > xdp.rxq = &rq->xdp_rxq; > > act = bpf_prog_run_xdp(xdp_prog, &xdp); > @@ -848,24 +856,27 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > switch (act) { > case XDP_PASS: > + metasize = xdp.data - xdp.data_meta; > + > /* recalculate offset to account for any header > - * adjustments. Note other cases do not build an > - * skb and avoid using offset > + * adjustments and minus the metasize to copy the > + * metadata in page_to_skb(). Note other cases do not > + * build an skb and avoid using offset > */ > - offset = xdp.data - > - page_address(xdp_page) - vi->hdr_len; > + offset = xdp.data - page_address(xdp_page) - > + vi->hdr_len - metasize; > > - /* recalculate len if xdp.data or xdp.data_end were > - * adjusted > + /* recalculate len if xdp.data, xdp.data_end or > + * xdp.data_meta were adjusted > */ > - len = xdp.data_end - xdp.data + vi->hdr_len; > + len = xdp.data_end - xdp.data + vi->hdr_len + metasize; > /* We can only create skb based on xdp_page. */ > if (unlikely(xdp_page != page)) { > rcu_read_unlock(); > put_page(page); > - head_skb = page_to_skb(vi, rq, xdp_page, > - offset, len, > - PAGE_SIZE, false); > + head_skb = page_to_skb(vi, rq, xdp_page, offset, > + len, PAGE_SIZE, false, > + metasize); > return head_skb; > } > break; > @@ -921,7 +932,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > goto err_skb; > } > > - head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog); > + head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog, > + metasize); > curr_skb = head_skb; > > if (unlikely(!curr_skb)) > -- > 2.24.1
