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From: Jesper Dangaard Brouer <brouer@redhat.com>
To: sameehj@amazon.com
Cc: "Toshiaki Makita" <toshiaki.makita1@gmail.com>,
	"Lorenzo Bianconi" <lorenzo@kernel.org>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Toshiaki Makita" <toshiaki.makita1@gmail.com>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	netdev@vger.kernel.org, bpf@vger.kernel.org, zorik@amazon.com,
	akiyano@amazon.com, gtzalik@amazon.com,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Daniel Borkmann" <borkmann@iogearbox.net>,
	"Alexei Starovoitov" <alexei.starovoitov@gmail.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Alexander Duyck" <alexander.duyck@gmail.com>,
	"Jeff Kirsher" <jeffrey.t.kirsher@intel.com>,
	"David Ahern" <dsahern@gmail.com>,
	"Willem de Bruijn" <willemdebruijn.kernel@gmail.com>,
	"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
	"Lorenzo Bianconi" <lorenzo@kernel.org>,
	"Saeed Mahameed" <saeedm@mellanox.com>,
	steffen.klassert@secunet.com
Subject: [PATCH net-next v2 10/33] veth: xdp using frame_sz in veth driver
Date: Thu, 30 Apr 2020 13:21:12 +0200
Message-ID: <158824567224.2172139.7951075614147304981.stgit@firesoul> (raw)
In-Reply-To: <158824557985.2172139.4173570969543904434.stgit@firesoul>

The veth driver can run XDP in "native" mode in it's own NAPI
handler, and since commit 9fc8d518d9d5 ("veth: Handle xdp_frames in
xdp napi ring") packets can come in two forms either xdp_frame or
skb, calling respectively veth_xdp_rcv_one() or veth_xdp_rcv_skb().

For packets to arrive in xdp_frame format, they will have been
redirected from an XDP native driver. In case of XDP_PASS or no
XDP-prog attached, the veth driver will allocate and create an SKB.

The current code in veth_xdp_rcv_one() xdp_frame case, had to guess
the frame truesize of the incoming xdp_frame, when using
veth_build_skb(). With xdp_frame->frame_sz this is not longer
necessary.

Calculating the frame_sz in veth_xdp_rcv_skb() skb case, is done
similar to the XDP-generic handling code in net/core/dev.c.

Cc: Toshiaki Makita <toshiaki.makita1@gmail.com>
Reviewed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Toshiaki Makita <toshiaki.makita1@gmail.com>
---
 drivers/net/veth.c |   22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index d5691bb84448..b586d2fa5551 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -405,10 +405,6 @@ static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
 {
 	struct sk_buff *skb;
 
-	if (!buflen) {
-		buflen = SKB_DATA_ALIGN(headroom + len) +
-			 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
-	}
 	skb = build_skb(head, buflen);
 	if (!skb)
 		return NULL;
@@ -583,6 +579,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
 		xdp.data = frame->data;
 		xdp.data_end = frame->data + frame->len;
 		xdp.data_meta = frame->data - frame->metasize;
+		xdp.frame_sz = frame->frame_sz;
 		xdp.rxq = &rq->xdp_rxq;
 
 		act = bpf_prog_run_xdp(xdp_prog, &xdp);
@@ -629,7 +626,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
 	rcu_read_unlock();
 
 	headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
-	skb = veth_build_skb(hard_start, headroom, len, 0);
+	skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz);
 	if (!skb) {
 		xdp_return_frame(frame);
 		stats->rx_drops++;
@@ -695,9 +692,8 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 			goto drop;
 		}
 
-		nskb = veth_build_skb(head,
-				      VETH_XDP_HEADROOM + mac_len, skb->len,
-				      PAGE_SIZE);
+		nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
+				      skb->len, PAGE_SIZE);
 		if (!nskb) {
 			page_frag_free(head);
 			goto drop;
@@ -715,6 +711,11 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 	xdp.data_end = xdp.data + pktlen;
 	xdp.data_meta = xdp.data;
 	xdp.rxq = &rq->xdp_rxq;
+
+	/* SKB "head" area always have tailroom for skb_shared_info */
+	xdp.frame_sz = (void *)skb_end_pointer(skb) - xdp.data_hard_start;
+	xdp.frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
 	orig_data = xdp.data;
 	orig_data_end = xdp.data_end;
 
@@ -758,6 +759,7 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 	}
 	rcu_read_unlock();
 
+	/* check if bpf_xdp_adjust_head was used */
 	delta = orig_data - xdp.data;
 	off = mac_len + delta;
 	if (off > 0)
@@ -765,9 +767,11 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 	else if (off < 0)
 		__skb_pull(skb, -off);
 	skb->mac_header -= delta;
+
+	/* check if bpf_xdp_adjust_tail was used */
 	off = xdp.data_end - orig_data_end;
 	if (off != 0)
-		__skb_put(skb, off);
+		__skb_put(skb, off); /* positive on grow, negative on shrink */
 	skb->protocol = eth_type_trans(skb, rq->dev);
 
 	metalen = xdp.data - xdp.data_meta;



  parent reply index

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <158824557985.2172139.4173570969543904434.stgit@firesoul>
2020-04-30 11:20 ` [PATCH net-next v2 01/33] xdp: add frame size to xdp_buff Jesper Dangaard Brouer
2020-04-30 11:20 ` [PATCH net-next v2 02/33] bnxt: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-30 11:20 ` [PATCH net-next v2 03/33] sfc: add XDP frame size Jesper Dangaard Brouer
2020-04-30 11:20 ` [PATCH net-next v2 04/33] mvneta: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-30 11:20 ` [PATCH net-next v2 05/33] net: netsec: Add support for XDP frame size Jesper Dangaard Brouer
2020-04-30 11:20 ` [PATCH net-next v2 06/33] net: XDP-generic determining " Jesper Dangaard Brouer
2020-04-30 11:20 ` [PATCH net-next v2 07/33] xdp: xdp_frame add member frame_sz and handle in convert_to_xdp_frame Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 08/33] xdp: cpumap redirect use frame_sz and increase skb_tailroom Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 09/33] veth: adjust hard_start offset on redirect XDP frames Jesper Dangaard Brouer
2020-04-30 11:21 ` Jesper Dangaard Brouer [this message]
2020-04-30 11:21 ` [PATCH net-next v2 11/33] dpaa2-eth: add XDP frame size Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 12/33] hv_netvsc: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-30 14:20   ` Haiyang Zhang
2020-05-01 14:47     ` Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 13/33] qlogic/qede: " Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 14/33] net: ethernet: ti: add XDP frame size to driver cpsw Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 15/33] ena: add XDP frame size to amazon NIC driver Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 16/33] mlx4: add XDP frame size and adjust max XDP MTU Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 17/33] net: thunderx: add XDP frame size Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 18/33] nfp: add XDP frame size to netronome driver Jesper Dangaard Brouer
2020-04-30 11:21 ` [PATCH net-next v2 19/33] tun: add XDP frame size Jesper Dangaard Brouer
2020-05-06 20:32   ` Michael S. Tsirkin
2020-04-30 11:22 ` [PATCH net-next v2 20/33] vhost_net: also populate " Jesper Dangaard Brouer
2020-05-06  6:41   ` Jason Wang
2020-05-06  6:49     ` Jason Wang
2020-05-06 20:33   ` Michael S. Tsirkin
2020-04-30 11:22 ` [PATCH net-next v2 21/33] virtio_net: add XDP frame size in two code paths Jesper Dangaard Brouer
2020-05-06 20:34   ` Michael S. Tsirkin
2020-05-08  2:05     ` Jason Wang
2020-05-08  7:21       ` Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 22/33] ixgbe: fix XDP redirect on archs with PAGE_SIZE above 4K Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 23/33] ixgbe: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 24/33] ixgbevf: add XDP frame size to VF driver Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 25/33] i40e: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 26/33] ice: " Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 27/33] xdp: for Intel AF_XDP drivers add XDP frame_sz Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 28/33] mlx5: rx queue setup time determine frame_sz for XDP Jesper Dangaard Brouer
2020-04-30 17:07   ` Tariq Toukan
2020-04-30 17:12     ` Tariq Toukan
2020-05-01 12:32       ` Jesper Dangaard Brouer
2020-05-08 10:49         ` Jesper Dangaard Brouer
2020-05-01 13:01     ` Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 29/33] xdp: allow bpf_xdp_adjust_tail() to grow packet size Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 30/33] xdp: clear grow memory in bpf_xdp_adjust_tail() Jesper Dangaard Brouer
2020-04-30 11:22 ` [PATCH net-next v2 31/33] bpf: add xdp.frame_sz in bpf_prog_test_run_xdp() Jesper Dangaard Brouer
2020-04-30 11:23 ` [PATCH net-next v2 32/33] selftests/bpf: adjust BPF selftest for xdp_adjust_tail Jesper Dangaard Brouer
2020-04-30 11:23 ` [PATCH net-next v2 33/33] selftests/bpf: xdp_adjust_tail add grow tail tests Jesper Dangaard Brouer

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