Commit a02e8964 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

virtio-net: ethtool configurable LRO 



Virtio-net devices negotiate LRO support with the host.
Display the initially negotiated state with ethtool -k.

Also allow configuring it with ethtool -K, reusing the existing
virtnet_set_guest_offloads helper that configures LRO for XDP.
This is conditional on VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.

Virtio-net negotiates TSO4 and TSO6 separately, but ethtool does not
distinguish between the two. Display LRO as on only if any offload
is active.

RTNL is held while calling virtnet_set_features, same as on the path
from virtnet_xdp_set.

Changes v1 -> v2
  - allow ethtool config (-K) only if VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
  - show LRO as enabled if any LRO variant is enabled
  - do not allow configuration while XDP is active
  - differentiate current features from the capable set, to restore
    on XDP down only those features that were active on XDP up
  - move test out of VIRTIO_NET_F_CSUM/TSO branch, which is tx only

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c3e53369

drivers/net/virtio_net.c

+33 −0
Original line number Diff line number Diff line
@@ -236,6 +236,7 @@ struct virtnet_info { 
	u32 speed;



	unsigned long guest_offloads;

	unsigned long guest_offloads_capable;



	/* failover when STANDBY feature enabled */

	struct failover *failover;
@@ -2479,6 +2480,31 @@ static int virtnet_get_phys_port_name(struct net_device *dev, char *buf, 
	return 0;

}



static int virtnet_set_features(struct net_device *dev,

				netdev_features_t features)

{

	struct virtnet_info *vi = netdev_priv(dev);

	u64 offloads;

	int err;



	if ((dev->features ^ features) & NETIF_F_LRO) {

		if (vi->xdp_queue_pairs)

			return -EBUSY;



		if (features & NETIF_F_LRO)

			offloads = vi->guest_offloads_capable;

		else

			offloads = 0;



		err = virtnet_set_guest_offloads(vi, offloads);

		if (err)

			return err;

		vi->guest_offloads = offloads;

	}



	return 0;

}



static const struct net_device_ops virtnet_netdev = {

	.ndo_open            = virtnet_open,

	.ndo_stop   	     = virtnet_close,
@@ -2493,6 +2519,7 @@ static const struct net_device_ops virtnet_netdev = { 
	.ndo_xdp_xmit		= virtnet_xdp_xmit,

	.ndo_features_check	= passthru_features_check,

	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,

	.ndo_set_features	= virtnet_set_features,

};



static void virtnet_config_changed_work(struct work_struct *work)
@@ -2951,6 +2978,11 @@ static int virtnet_probe(struct virtio_device *vdev) 
	}

	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))

		dev->features |= NETIF_F_RXCSUM;

	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||

	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))

		dev->features |= NETIF_F_LRO;

	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))

		dev->hw_features |= NETIF_F_LRO;



	dev->vlan_features = dev->features;
@@ -3080,6 +3112,7 @@ static int virtnet_probe(struct virtio_device *vdev) 
	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)

		if (virtio_has_feature(vi->vdev, guest_offloads[i]))

			set_bit(guest_offloads[i], &vi->guest_offloads);

	vi->guest_offloads_capable = vi->guest_offloads;



	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",

		 dev->name, max_queue_pairs);

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