ixgbevf: Add support for meta data

Add support for XDP meta data when using build skb.

Based on commit 366a88fe2f40 ("bpf, ixgbe: add meta data support")

Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 5167e81e0cf12eef28c1357a629a806c3015ec7d..3d9033f26effa743fc4142a6b99a64d7a5effcfd 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -889,6 +889,20 @@ struct sk_buff *ixgbevf_construct_skb(struct ixgbevf_ring *rx_ring,
 #if L1_CACHE_BYTES < 128
        prefetch(xdp->data + L1_CACHE_BYTES);
 #endif
+       /* Note, we get here by enabling legacy-rx via:
+        *
+        *    ethtool --set-priv-flags <dev> legacy-rx on
+        *
+        * In this mode, we currently get 0 extra XDP headroom as
+        * opposed to having legacy-rx off, where we process XDP
+        * packets going to stack via ixgbevf_build_skb().
+        *
+        * For ixgbevf_construct_skb() mode it means that the
+        * xdp->data_meta will always point to xdp->data, since
+        * the helper cannot expand the head. Should this ever
+        * changed in future for legacy-rx mode on, then lets also
+        * add xdp->data_meta handling here.
+        */
 
        /* allocate a skb to store the frags */
        skb = napi_alloc_skb(&rx_ring->q_vector->napi, IXGBEVF_RX_HDR_SIZE);
@@ -936,6 +950,7 @@ static struct sk_buff *ixgbevf_build_skb(struct ixgbevf_ring *rx_ring,
                                         struct xdp_buff *xdp,
                                         union ixgbe_adv_rx_desc *rx_desc)
 {
+       unsigned int metasize = xdp->data - xdp->data_meta;
 #if (PAGE_SIZE < 8192)
        unsigned int truesize = ixgbevf_rx_pg_size(rx_ring) / 2;
 #else
@@ -945,10 +960,14 @@ static struct sk_buff *ixgbevf_build_skb(struct ixgbevf_ring *rx_ring,
 #endif
        struct sk_buff *skb;
 
-       /* prefetch first cache line of first page */
-       prefetch(xdp->data);
+       /* Prefetch first cache line of first page. If xdp->data_meta
+        * is unused, this points to xdp->data, otherwise, we likely
+        * have a consumer accessing first few bytes of meta data,
+        * and then actual data.
+        */
+       prefetch(xdp->data_meta);
 #if L1_CACHE_BYTES < 128
-       prefetch(xdp->data + L1_CACHE_BYTES);
+       prefetch(xdp->data_meta + L1_CACHE_BYTES);
 #endif
 
        /* build an skb around the page buffer */
@@ -959,6 +978,8 @@ static struct sk_buff *ixgbevf_build_skb(struct ixgbevf_ring *rx_ring,
        /* update pointers within the skb to store the data */
        skb_reserve(skb, xdp->data - xdp->data_hard_start);
        __skb_put(skb, xdp->data_end - xdp->data);
+       if (metasize)
+               skb_metadata_set(skb, metasize);
 
        /* update buffer offset */
 #if (PAGE_SIZE < 8192)
@@ -1126,7 +1147,7 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
                if (!skb) {
                        xdp.data = page_address(rx_buffer->page) +
                                   rx_buffer->page_offset;
-                       xdp_set_data_meta_invalid(&xdp);
+                       xdp.data_meta = xdp.data;
                        xdp.data_hard_start = xdp.data -
                                              ixgbevf_rx_offset(rx_ring);
                        xdp.data_end = xdp.data + size;