diff options
Diffstat (limited to 'drivers/net/virtio_net.c')
| -rw-r--r-- | drivers/net/virtio_net.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 87838cbe38cf..cbba9d2e8f32 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1005,6 +1005,24 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, * xdp.data_meta were adjusted */ len = xdp.data_end - xdp.data + vi->hdr_len + metasize; + + /* recalculate headroom if xdp.data or xdp_data_meta + * were adjusted, note that offset should always point + * to the start of the reserved bytes for virtio_net + * header which are followed by xdp.data, that means + * that offset is equal to the headroom (when buf is + * starting at the beginning of the page, otherwise + * there is a base offset inside the page) but it's used + * with a different starting point (buf start) than + * xdp.data (buf start + vnet hdr size). If xdp.data or + * data_meta were adjusted by the xdp prog then the + * headroom size has changed and so has the offset, we + * can use data_hard_start, which points at buf start + + * vnet hdr size, to calculate the new headroom and use + * it later to compute buf start in page_to_skb() + */ + headroom = xdp.data - xdp.data_hard_start - metasize; + /* We can only create skb based on xdp_page. */ if (unlikely(xdp_page != page)) { rcu_read_unlock(); @@ -1012,7 +1030,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, head_skb = page_to_skb(vi, rq, xdp_page, offset, len, PAGE_SIZE, false, metasize, - VIRTIO_XDP_HEADROOM); + headroom); return head_skb; } break; |