From 49ddd63d21bcc62c14f06122fbe47b2e51f570d7 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Wed, 8 Dec 2021 15:06:54 +0100 Subject: [PATCH] i40e: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb BugLink: https://bugs.launchpad.net/bugs/1969110 [ Upstream commit bc97f9c6f988b31b728eb47a94ca825401dbeffe ] {__,}napi_alloc_skb() allocates and reserves additional NET_SKB_PAD + NET_IP_ALIGN for any skb. OTOH, i40e_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: 0a714186d3c0 ("i40e: add AF_XDP zero-copy Rx support") Signed-off-by: Alexander Lobakin Reviewed-by: Michal Swiatkowski Acked-by: Jesper Dangaard Brouer Tested-by: Kiran Bhandare Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin (cherry picked from commit 968c76e96afde944092c1afdcec799d2a558f221) Signed-off-by: Paolo Pisati --- drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c index e7e778ca074c..48f5319a3d41 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -248,13 +248,11 @@ static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring, struct sk_buff *skb; /* allocate a skb to store the frags */ - skb = __napi_alloc_skb(&rx_ring->q_vector->napi, - xdp->data_end - xdp->data_hard_start, + skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) goto out; - skb_reserve(skb, xdp->data - xdp->data_hard_start); memcpy(__skb_put(skb, datasize), xdp->data, datasize); if (metasize) skb_metadata_set(skb, metasize); -- 2.39.5