intel: xsk: initialize skb_frag_t::bv_offset in ZC drivers

Ice and i40e ZC drivers currently set offset of a frag within
skb_shared_info to 0, which is incorrect. xdp_buffs that come from
xsk_buff_pool always have 256 bytes of a headroom, so they need to be
taken into account to retrieve xdp_buff::data via skb_frag_address().
Otherwise, bpf_xdp_frags_increase_tail() would be starting its job from
xdp_buff::data_hard_start which would result in overwriting existing
payload.

Fixes: 1c9ba9c14658 ("i40e: xsk: add RX multi-buffer support")
Fixes: 1bbc04de607b ("ice: xsk: add RX multi-buffer support")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-8-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 82aca0d..1150000 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -414,7 +414,8 @@ i40e_add_xsk_frag(struct i40e_ring *rx_ring, struct xdp_buff *first,
        }
 
        __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
-                                  virt_to_page(xdp->data_hard_start), 0, size);
+                                  virt_to_page(xdp->data_hard_start),
+                                  XDP_PACKET_HEADROOM, size);
        sinfo->xdp_frags_size += size;
        xsk_buff_add_frag(xdp);
 

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index d9073a6..8b81a16 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -825,7 +825,8 @@ ice_add_xsk_frag(struct ice_rx_ring *rx_ring, struct xdp_buff *first,
        }
 
        __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
-                                  virt_to_page(xdp->data_hard_start), 0, size);
+                                  virt_to_page(xdp->data_hard_start),
+                                  XDP_PACKET_HEADROOM, size);
        sinfo->xdp_frags_size += size;
        xsk_buff_add_frag(xdp);