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From: Stanislav Fomichev <sdf@google.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
	haoluo@google.com, jolsa@kernel.org,
	David Ahern <dsahern@gmail.com>, Jakub Kicinski <kuba@kernel.org>,
	Willem de Bruijn <willemb@google.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Anatoly Burakov <anatoly.burakov@intel.com>,
	Alexander Lobakin <alexandr.lobakin@intel.com>,
	Magnus Karlsson <magnus.karlsson@gmail.com>,
	Maryam Tahhan <mtahhan@redhat.com>,
	xdp-hints@xdp-project.net, netdev@vger.kernel.org
Subject: [xdp-hints] [RFC bpf-next v2 04/14] veth: Support rx timestamp metadata for xdp
Date: Thu,  3 Nov 2022 20:25:22 -0700	[thread overview]
Message-ID: <20221104032532.1615099-5-sdf@google.com> (raw)
In-Reply-To: <20221104032532.1615099-1-sdf@google.com>

xskxceiver conveniently setups up veth pairs so it seems logical
to use veth as an example for some of the metadata handling.

We timestamp skb right when we "receive" it, store its
pointer in new veth_xdp_buff wrapper and generate BPF bytecode to
reach it from the BPF program.

This largely follows the idea of "store some queue context in
the xdp_buff/xdp_frame so the metadata can be reached out
from the BPF program".

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 drivers/net/veth.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 917ba57453c1..0e629ceb087b 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -25,6 +25,7 @@
 #include <linux/filter.h>
 #include <linux/ptr_ring.h>
 #include <linux/bpf_trace.h>
+#include <linux/bpf_patch.h>
 #include <linux/net_tstamp.h>
 
 #define DRV_NAME	"veth"
@@ -118,6 +119,7 @@ static struct {
 
 struct veth_xdp_buff {
 	struct xdp_buff xdp;
+	struct sk_buff *skb;
 };
 
 static int veth_get_link_ksettings(struct net_device *dev,
@@ -602,6 +604,7 @@ static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 
 		xdp_convert_frame_to_buff(frame, xdp);
 		xdp->rxq = &rq->xdp_rxq;
+		vxbuf.skb = NULL;
 
 		act = bpf_prog_run_xdp(xdp_prog, xdp);
 
@@ -826,6 +829,7 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 
 	orig_data = xdp->data;
 	orig_data_end = xdp->data_end;
+	vxbuf.skb = skb;
 
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 
@@ -942,6 +946,7 @@ static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 			struct sk_buff *skb = ptr;
 
 			stats->xdp_bytes += skb->len;
+			__net_timestamp(skb);
 			skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 			if (skb) {
 				if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
@@ -1665,6 +1670,31 @@ static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 	}
 }
 
+static void veth_unroll_kfunc(const struct bpf_prog *prog, u32 func_id,
+			      struct bpf_patch *patch)
+{
+	if (func_id == xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP_SUPPORTED)) {
+		/* return true; */
+		bpf_patch_append(patch, BPF_MOV64_IMM(BPF_REG_0, 1));
+	} else if (func_id == xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP)) {
+		bpf_patch_append(patch,
+			/* r5 = ((struct veth_xdp_buff *)r1)->skb; */
+			BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_1,
+				    offsetof(struct veth_xdp_buff, skb)),
+			/* if (r5 == NULL) { */
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_5, 0, 2),
+			/*	return 0; */
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_A(1),
+			/* } else { */
+			/*	return ((struct sk_buff *)r5)->tstamp; */
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_5,
+				    offsetof(struct sk_buff, tstamp)),
+			/* } */
+		);
+	}
+}
+
 static const struct net_device_ops veth_netdev_ops = {
 	.ndo_init            = veth_dev_init,
 	.ndo_open            = veth_open,
@@ -1684,6 +1714,7 @@ static const struct net_device_ops veth_netdev_ops = {
 	.ndo_bpf		= veth_xdp,
 	.ndo_xdp_xmit		= veth_ndo_xdp_xmit,
 	.ndo_get_peer_dev	= veth_peer_dev,
+	.ndo_unroll_kfunc       = veth_unroll_kfunc,
 };
 
 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
-- 
2.38.1.431.g37b22c650d-goog


  parent reply	other threads:[~2022-11-04  3:25 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-04  3:25 [xdp-hints] [RFC bpf-next v2 00/14] xdp: hints via kfuncs Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 01/14] bpf: Introduce bpf_patch Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 02/14] bpf: Support inlined/unrolled kfuncs for xdp metadata Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 03/14] veth: Introduce veth_xdp_buff wrapper for xdp_buff Stanislav Fomichev
2022-11-04  3:25 ` Stanislav Fomichev [this message]
2022-11-09 11:21   ` [xdp-hints] Re: [RFC bpf-next v2 04/14] veth: Support rx timestamp metadata for xdp Toke Høiland-Jørgensen
2022-11-09 21:34     ` Stanislav Fomichev
2022-11-10  0:25   ` John Fastabend
2022-11-10  1:02     ` Stanislav Fomichev
2022-11-10  1:35       ` John Fastabend
2022-11-10  6:44         ` Stanislav Fomichev
2022-11-10 17:39           ` John Fastabend
2022-11-10 18:52             ` Stanislav Fomichev
2022-11-11 10:41             ` Jesper Dangaard Brouer
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 05/14] selftests/bpf: Verify xdp_metadata xdp->af_xdp path Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 06/14] xdp: Carry over xdp metadata into skb context Stanislav Fomichev
2022-11-07 22:01   ` [xdp-hints] " Martin KaFai Lau
2022-11-08 21:54     ` Stanislav Fomichev
2022-11-09  3:07       ` Martin KaFai Lau
2022-11-09  4:19         ` Martin KaFai Lau
2022-11-09 11:10           ` Toke Høiland-Jørgensen
2022-11-09 18:22             ` Martin KaFai Lau
2022-11-09 21:33               ` Stanislav Fomichev
2022-11-10  0:13                 ` Martin KaFai Lau
2022-11-10  1:02                   ` Stanislav Fomichev
2022-11-10 14:26                     ` Toke Høiland-Jørgensen
2022-11-10 18:52                       ` Stanislav Fomichev
2022-11-10 23:14                         ` Toke Høiland-Jørgensen
2022-11-10 23:52                           ` Stanislav Fomichev
2022-11-11  0:10                             ` Toke Høiland-Jørgensen
2022-11-11  0:45                               ` Martin KaFai Lau
2022-11-11  9:37                                 ` Toke Høiland-Jørgensen
2022-11-11  0:33                             ` Martin KaFai Lau
2022-11-11  0:57                               ` Stanislav Fomichev
2022-11-11  1:26                                 ` Martin KaFai Lau
2022-11-11  9:41                                   ` Toke Høiland-Jørgensen
2022-11-10 23:58                         ` Martin KaFai Lau
2022-11-11  0:20                           ` Stanislav Fomichev
2022-11-10 14:19               ` Toke Høiland-Jørgensen
2022-11-10 19:04                 ` Martin KaFai Lau
2022-11-10 23:29                   ` Toke Høiland-Jørgensen
2022-11-11  1:39                     ` Martin KaFai Lau
2022-11-11  9:44                       ` Toke Høiland-Jørgensen
2022-11-10  1:26             ` John Fastabend
2022-11-10 14:32               ` Toke Høiland-Jørgensen
2022-11-10 17:30                 ` John Fastabend
2022-11-10 22:49                   ` Toke Høiland-Jørgensen
2022-11-10  1:09   ` John Fastabend
2022-11-10  6:44     ` Stanislav Fomichev
2022-11-10 21:21       ` David Ahern
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 07/14] selftests/bpf: Verify xdp_metadata xdp->skb path Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 08/14] bpf: Helper to simplify calling kernel routines from unrolled kfuncs Stanislav Fomichev
2022-11-05  0:40   ` [xdp-hints] " Alexei Starovoitov
2022-11-05  2:18     ` Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 09/14] ice: Introduce ice_xdp_buff wrapper for xdp_buff Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 10/14] ice: Support rx timestamp metadata for xdp Stanislav Fomichev
2022-11-04 14:35   ` [xdp-hints] " Alexander Lobakin
2022-11-04 18:21     ` Stanislav Fomichev
2022-11-07 17:11       ` Alexander Lobakin
2022-11-07 19:10         ` Stanislav Fomichev
2022-12-15 11:54   ` Larysa Zaremba
2022-12-15 14:29     ` Toke Høiland-Jørgensen
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 11/14] mlx4: Introduce mlx4_xdp_buff wrapper for xdp_buff Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 12/14] mxl4: Support rx timestamp metadata for xdp Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 13/14] bnxt: Introduce bnxt_xdp_buff wrapper for xdp_buff Stanislav Fomichev
2022-11-04  3:25 ` [xdp-hints] [RFC bpf-next v2 14/14] bnxt: Support rx timestamp metadata for xdp Stanislav Fomichev

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