[PATCH 5.16 0441/1017] ice: respect metadata on XSK Rx to skb

Greg Kroah-Hartman
2022-04-05T09:27:19Z

From: Alexander Lobakin <alexandr.lobakin@intel.com>

[ Upstream commit 45a34ca68070e34e09d5bf4309f7f1f286a27fc7 ]

For now, if the XDP prog returns XDP_PASS on XSK, the metadata will
be lost as it doesn't get copied to the skb.

Copy it along with the frame headers. Account its size on skb
allocation, and when copying just treat it as a part of the frame
and do a pull after to "move" it to the "reserved" zone.

net_prefetch() xdp->data_meta and align the copy size to speed-up
memcpy() a little and better match ice_construct_skb().

Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
Suggested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Suggested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/ice/ice_xsk.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index a2c79431afd8..ac97cf3c5804 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -428,18 +428,24 @@ static void ice_bump_ntc(struct ice_rx_ring *rx_ring)
static struct sk_buff *
ice_construct_skb_zc(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp)
{
+ unsigned int totalsize = xdp->data_end - xdp->data_meta;
unsigned int metasize = xdp->data - xdp->data_meta;
- unsigned int datasize = xdp->data_end - xdp->data;
struct sk_buff *skb;

- skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize,
+ net_prefetch(xdp->data_meta);
+
+ skb = __napi_alloc_skb(&rx_ring->q_vector->napi, totalsize,
GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!skb))
return NULL;

- memcpy(__skb_put(skb, datasize), xdp->data, datasize);
- if (metasize)
+ memcpy(__skb_put(skb, totalsize), xdp->data_meta,
+ ALIGN(totalsize, sizeof(long)));
+
+ if (metasize) {
skb_metadata_set(skb, metasize);
+ __skb_pull(skb, metasize);
+ }

xsk_buff_free(xdp);
return skb;
--
2.34.1