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@xxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6fb7b658a6cc..ed8299343728 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -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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