Re: XDP_TX for virtio_net not working in recent kernel?

2018-04-12 Thread Kimitoshi Takahashi 

Hello Jason,

The patch fixed the issue.
Thank you very much!


On 04/11/2018 10:50 AM, Jason Wang wrote:


I suspect a kick is missed in the XDP_TX case.

Could you please try the attached patch to see if it fixes the issue?

Thanks


--
Kimitoshi Takahashi

Re: XDP_TX for virtio_net not working in recent kernel?

2018-04-10 Thread Jason Wang 



On 2018年04月10日 18:17, Daniel Borkmann wrote:

[ +jason +netdev ]

On 04/10/2018 12:49 AM, Kimitoshi Takahashi wrote:

Hello,

I'm totally newbie.

I want to try some examples under the samples/bpf of the kernel tree using the 
virtio_net driver in kvm, in order to get familiar with the XDP. However, it 
seems to me that for kernels newer than linux-4.15, the xdp2 and xdp_tx_tunnel 
are not working in the case of virtio_net.

Can somebody help me out to make them working?


1) For linux-4.11.12, linux-4.12.14, and linux-4.14.31, xdp2 and xdp_tx_tunnel 
are working.

[xdp2]
10.0.0.27# ./xdp2 2 (or ./xdp -N 2)

10.0.0.254# hping3 10.0.0.27 -p 5000 -2

10.0.0.254# tcpdump -nei kbr0 udp port 5000
06:18:37.677070 2e:c9:83:fb:5b:f3 > 52:54:00:11:00:1b, ethertype IPv4 (0x0800), 
length 42: 10.0.0.254.2982 > 10.0.0.27.5000: UDP, length 0
06:18:37.677265 52:54:00:11:00:1b > 2e:c9:83:fb:5b:f3, ethertype IPv4 (0x0800), 
length 42: 10.0.0.254.2982 > 10.0.0.27.5000: UDP, length 0

I can see the UDP packets with MAC addresses swapped.

[xdp_tx_tunnel]

10.0.0.254# telnet 10.1.2.1 80

10.0.0.27# ./xdp_tx_iptunnel -i 2 -a 10.1.2.1 -p 80 -s 10.0.0.27 -d 10.0.0.24 
-m 52:54:00:11:00:18

10.0.0.24# tcpdump -nei any proto 4
22:08:20.510354  In 52:54:00:11:00:1b ethertype IPv4 (0x0800), length 96: 10.0.0.27 
> 10.0.0.24: 10.0.0.254.60826 > 10.1.2.1.80: Flags [S], seq 3224377720, win 
29200, options [mss 1460,sackOK,TS val 217801953 ecr 0,nop,wscale 7], length 0 
(ipip-proto-4)

I can see the encapsulated SYN packet that is forwarded by the 10.0.0.27.

2) For linux-4.15, linux-4.15.5, linux-4.15.13 and linux-4.16.1, xdp2 and 
xdp_tx_tunnel are NOT working.

[xdp2]
10.0.0.27# ./xdp2 -N 2

10.0.0.254# hping3 10.0.0.27 -p 5000 -2

10.0.0.254# tcpdump -nei br0 udp port 5000
06:45:34.810046 2e:c9:83:fb:5b:f3 > 52:54:00:11:00:1b, ethertype IPv4 (0x0800), 
length 42: 10.0.0.254.2346 > 10.0.0.27.5000: UDP, length 0
06:45:35.810176 2e:c9:83:fb:5b:f3 > 52:54:00:11:00:1b, ethertype IPv4 (0x0800), 
length 42: 10.0.0.254.2347 > 10.0.0.27.5000: UDP, length 0

Only the outgoing packets can be seen.

[xdp_tx_tunnel]

10.0.0.254# telnet 10.1.2.1 80

10.0.0.27# ./xdp_tx_iptunnel -i 2 -a 10.1.2.1 -p 80 -s 10.0.0.27 -d 10.0.0.24 
-m 52:54:00:11:00:18

10.0.0.24# tcpdump -nei any proto 4

I can NOT see the encapsulated SYN packet that is forwarded by the 10.0.0.27.


--
Sincerely,
Takahashi Kimitoshi


I suspect a kick is missed in the XDP_TX case.

Could you please try the attached patch to see if it fixes the issue?

Thanks
>From f37d74d65671e1a1f1a0c4dd59bf1df69b47f30a Mon Sep 17 00:00:00 2001
From: Jason Wang 
Date: Mon, 22 Jan 2018 17:07:03 +0800
Subject: [PATCH] virtio-net: add missing virtqueue kick when flushing packets

We tends to batch submitting packets during XDP_TX. This requires to
kick virtqueue after a batch, we tried to do it through
xdp_do_flush_map() which only makes sense for devmap not XDP_TX. So
explicitly kick the virtqueue in this case.

Signed-off-by: Jason Wang 
---
 drivers/net/virtio_net.c | 11 +--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2337460..d8e1aea 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1269,7 +1269,9 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
 {
 	struct receive_queue *rq =
 		container_of(napi, struct receive_queue, napi);
-	unsigned int received;
+	struct virtnet_info *vi = rq->vq->vdev->priv;
+	struct send_queue *sq;
+	unsigned int received, qp;
 	bool xdp_xmit = false;
 
 	virtnet_poll_cleantx(rq);
@@ -1280,8 +1282,13 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
 	if (received < budget)
 		virtqueue_napi_complete(napi, rq->vq, received);
 
-	if (xdp_xmit)
+	if (xdp_xmit) {
+		qp = vi->curr_queue_pairs - vi->xdp_queue_pairs +
+		 smp_processor_id();
+		sq = >sq[qp];
+		virtqueue_kick(sq->vq);
 		xdp_do_flush_map();
+	}
 
 	return received;
 }
-- 
2.7.4

Re: XDP_TX for virtio_net not working in recent kernel?

2018-04-10 Thread Daniel Borkmann 
[ +jason +netdev ]

On 04/10/2018 12:49 AM, Kimitoshi Takahashi wrote:
> Hello,
> 
> I'm totally newbie.
> 
> I want to try some examples under the samples/bpf of the kernel tree using 
> the virtio_net driver in kvm, in order to get familiar with the XDP. However, 
> it seems to me that for kernels newer than linux-4.15, the xdp2 and 
> xdp_tx_tunnel are not working in the case of virtio_net.
> 
> Can somebody help me out to make them working?
> 
> 
> 1) For linux-4.11.12, linux-4.12.14, and linux-4.14.31, xdp2 and 
> xdp_tx_tunnel are working.
> 
> [xdp2]
> 10.0.0.27# ./xdp2 2 (or ./xdp -N 2)
> 
> 10.0.0.254# hping3 10.0.0.27 -p 5000 -2
> 
> 10.0.0.254# tcpdump -nei kbr0 udp port 5000
> 06:18:37.677070 2e:c9:83:fb:5b:f3 > 52:54:00:11:00:1b, ethertype IPv4 
> (0x0800), length 42: 10.0.0.254.2982 > 10.0.0.27.5000: UDP, length 0
> 06:18:37.677265 52:54:00:11:00:1b > 2e:c9:83:fb:5b:f3, ethertype IPv4 
> (0x0800), length 42: 10.0.0.254.2982 > 10.0.0.27.5000: UDP, length 0
> 
> I can see the UDP packets with MAC addresses swapped.
> 
> [xdp_tx_tunnel]
> 
> 10.0.0.254# telnet 10.1.2.1 80
> 
> 10.0.0.27# ./xdp_tx_iptunnel -i 2 -a 10.1.2.1 -p 80 -s 10.0.0.27 -d 10.0.0.24 
> -m 52:54:00:11:00:18
> 
> 10.0.0.24# tcpdump -nei any proto 4
> 22:08:20.510354  In 52:54:00:11:00:1b ethertype IPv4 (0x0800), length 96: 
> 10.0.0.27 > 10.0.0.24: 10.0.0.254.60826 > 10.1.2.1.80: Flags [S], seq 
> 3224377720, win 29200, options [mss 1460,sackOK,TS val 217801953 ecr 
> 0,nop,wscale 7], length 0 (ipip-proto-4)
> 
> I can see the encapsulated SYN packet that is forwarded by the 10.0.0.27.
> 
> 2) For linux-4.15, linux-4.15.5, linux-4.15.13 and linux-4.16.1, xdp2 and 
> xdp_tx_tunnel are NOT working.
> 
> [xdp2]
> 10.0.0.27# ./xdp2 -N 2
> 
> 10.0.0.254# hping3 10.0.0.27 -p 5000 -2
> 
> 10.0.0.254# tcpdump -nei br0 udp port 5000
> 06:45:34.810046 2e:c9:83:fb:5b:f3 > 52:54:00:11:00:1b, ethertype IPv4 
> (0x0800), length 42: 10.0.0.254.2346 > 10.0.0.27.5000: UDP, length 0
> 06:45:35.810176 2e:c9:83:fb:5b:f3 > 52:54:00:11:00:1b, ethertype IPv4 
> (0x0800), length 42: 10.0.0.254.2347 > 10.0.0.27.5000: UDP, length 0
> 
> Only the outgoing packets can be seen.
> 
> [xdp_tx_tunnel]
> 
> 10.0.0.254# telnet 10.1.2.1 80
> 
> 10.0.0.27# ./xdp_tx_iptunnel -i 2 -a 10.1.2.1 -p 80 -s 10.0.0.27 -d 10.0.0.24 
> -m 52:54:00:11:00:18
> 
> 10.0.0.24# tcpdump -nei any proto 4
> 
> I can NOT see the encapsulated SYN packet that is forwarded by the 10.0.0.27.
> 
> 
> -- 
> Sincerely,
> Takahashi Kimitoshi