[PATCH bpf RFC-V2 3/5] veth: bpf_xdp_metadata_rx_hash return xdp rss hash type

Jesper Dangaard Brouer
2023-03-29T16:30:37Z

Update API for bpf_xdp_metadata_rx_hash() by returning xdp rss hash type.

The veth driver currently only support XDP-hints based on SKB code path.
The SKB have lost information about the RSS hash type, by compressing
the information down to a single bitfield skb->l4_hash, that only knows
if this was a L4 hash value.

In preparation for veth, the xdp_rss_hash_type have an L4 indication
bit that allow us to return a meaningful L4 indication when working
with SKB based packets.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
drivers/net/veth.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 046461ee42ea..770eee664b4c 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1619,12 +1619,13 @@ static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
{
struct veth_xdp_buff *_ctx = (void *)ctx;
+ struct sk_buff *skb = _ctx->skb;

- if (!_ctx->skb)
+ if (!skb)
return -ENODATA;

- *hash = skb_get_hash(_ctx->skb);
- return 0;
+ *hash = skb_get_hash(skb);
+ return skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
}

static const struct net_device_ops veth_netdev_ops = {