[PATCH bpf RFC-V3 3/5] veth: bpf_xdp_metadata_rx_hash add xdp rss hash type

From: Jesper Dangaard Brouer
Date: Thu Mar 30 2023 - 13:09:04 EST


Update API for bpf_xdp_metadata_rx_hash() with arg for 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@xxxxxxxxxx>
---
drivers/net/veth.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index c1178915496d..f5381e7c9310 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1648,14 +1648,19 @@ static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
return 0;
}

-static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
+static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
+ enum xdp_rss_hash_type *rss_type)
+
{
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);
+ *hash = skb_get_hash(skb);
+ *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
+
return 0;
}