This is a note to let you know that I've just added the patch titled ice: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb to the 5.17-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ice-don-t-reserve-excessive-xdp_packet_headroom-on-x.patch and it can be found in the queue-5.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2760be5475ebc1002174e76c641117bbc88a2bae Author: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> Date: Wed Dec 8 15:06:57 2021 +0100 ice: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb [ Upstream commit dc44572d195e10ec41a03e09b3b5addab4af5cea ] {__,}napi_alloc_skb() allocates and reserves additional NET_SKB_PAD + NET_IP_ALIGN for any skb. OTOH, ice_construct_skb_zc() currently allocates and reserves additional `xdp->data - xdp->data_hard_start`, which is XDP_PACKET_HEADROOM for XSK frames. There's no need for that at all as the frame is post-XDP and will go only to the networking stack core. Pass the size of the actual data only to __napi_alloc_skb() and don't reserve anything. This will give enough headroom for stack processing. Fixes: 2d4238f55697 ("ice: Add support for AF_XDP") Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> Reviewed-by: Michal Swiatkowski <michal.swiatkowski@xxxxxxxxxxxxxxx> Tested-by: Kiran Bhandare <kiranx.bhandare@xxxxxxxxx> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c index 2388837d6d6c..8fd8052edf09 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -428,17 +428,15 @@ 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 datasize_hard = xdp->data_end - xdp->data_hard_start; 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_hard, + skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) return NULL; - skb_reserve(skb, xdp->data - xdp->data_hard_start); memcpy(__skb_put(skb, datasize), xdp->data, datasize); if (metasize) skb_metadata_set(skb, metasize);