net: mana: Add metadata support for xdp mode

Set metadata size building the skb from xdp_buff in mana driver.
mana driver sets xdp headroom to XDP_PACKET_HEADROOM so the headroom is
large enough to contain xdp_frame and xdp metadata.
Please note this patch is just compiled tested.

Reviewed-by: Michal Kubiak <[email protected]>
Signed-off-by: Lorenzo Bianconi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: LorenzoBianconi

drivers/net/ethernet/microsoft/mana/mana_bpf.c

@@ -91,7 +91,7 @@ u32 mana_run_xdp(struct net_device *ndev, struct mana_rxq *rxq,
 		goto out;
 
 	xdp_init_buff(xdp, PAGE_SIZE, &rxq->xdp_rxq);
-	xdp_prepare_buff(xdp, buf_va, XDP_PACKET_HEADROOM, pkt_len, false);
+	xdp_prepare_buff(xdp, buf_va, XDP_PACKET_HEADROOM, pkt_len, true);
 
 	act = bpf_prog_run_xdp(prog, xdp);
 

drivers/net/ethernet/microsoft/mana/mana_en.c

@@ -1559,8 +1559,12 @@ static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
 		return NULL;
 
 	if (xdp->data_hard_start) {
+		u32 metasize = xdp->data - xdp->data_meta;
+
 		skb_reserve(skb, xdp->data - xdp->data_hard_start);
 		skb_put(skb, xdp->data_end - xdp->data);
+		if (metasize)
+			skb_metadata_set(skb, metasize);
 		return skb;
 	}