Commit 754b8a21 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Alexei Starovoitov
Browse files

virtio_net: setup xdp_rxq_info 



The virtio_net driver doesn't dynamically change the RX-ring queue
layout and backing pages, but instead reject XDP setup if all the
conditions for XDP is not meet.  Thus, the xdp_rxq_info also remains
fairly static.  This allow us to simply add the reg/unreg to
net_device open/close functions.

Driver hook points for xdp_rxq_info:
 * reg  : virtnet_open
 * unreg: virtnet_close

V3:
 - bugfix, also setup xdp.rxq in receive_mergeable()
 - Tested bpf-sample prog inside guest on a virtio_net device

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 8bf5c4ee

drivers/net/virtio_net.c

+13 −1
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/average.h>

#include <linux/filter.h>

#include <net/route.h>

#include <net/xdp.h>



static int napi_weight = NAPI_POLL_WEIGHT;

module_param(napi_weight, int, 0444);
@@ -115,6 +116,8 @@ struct receive_queue { 


	/* Name of this receive queue: input.$index */

	char name[40];



	struct xdp_rxq_info xdp_rxq;

};



struct virtnet_info {
@@ -559,6 +562,7 @@ static struct sk_buff *receive_small(struct net_device *dev, 
		xdp.data = xdp.data_hard_start + xdp_headroom;

		xdp_set_data_meta_invalid(&xdp);

		xdp.data_end = xdp.data + len;

		xdp.rxq = &rq->xdp_rxq;

		orig_data = xdp.data;

		act = bpf_prog_run_xdp(xdp_prog, &xdp);
@@ -692,6 +696,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, 
		xdp.data = data + vi->hdr_len;

		xdp_set_data_meta_invalid(&xdp);

		xdp.data_end = xdp.data + (len - vi->hdr_len);

		xdp.rxq = &rq->xdp_rxq;



		act = bpf_prog_run_xdp(xdp_prog, &xdp);



		if (act != XDP_PASS)
@@ -1225,13 +1231,18 @@ static int virtnet_poll(struct napi_struct *napi, int budget) 
static int virtnet_open(struct net_device *dev)

{

	struct virtnet_info *vi = netdev_priv(dev);

	int i;

	int i, err;



	for (i = 0; i < vi->max_queue_pairs; i++) {

		if (i < vi->curr_queue_pairs)

			/* Make sure we have some buffers: if oom use wq. */

			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))

				schedule_delayed_work(&vi->refill, 0);



		err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);

		if (err < 0)

			return err;



		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);

		virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);

	}
@@ -1560,6 +1571,7 @@ static int virtnet_close(struct net_device *dev) 
	cancel_delayed_work_sync(&vi->refill);



	for (i = 0; i < vi->max_queue_pairs; i++) {

		xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);

		napi_disable(&vi->rq[i].napi);

		virtnet_napi_tx_disable(&vi->sq[i].napi);

	}

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