Commit 6f45ab3e authored by Daniel Jurgens's avatar Daniel Jurgens Committed by Paolo Abeni
Browse files

virtio_net: Add a lock for the command VQ. 



The command VQ will no longer be protected by the RTNL lock. Use a
mutex to protect the control buffer header and the VQ.

Signed-off-by: default avatarDaniel Jurgens <danielj@nvidia.com>
Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
Reviewed-by: default avatarHeng Qi <hengqi@linux.alibaba.com>
Tested-by: default avatarHeng Qi <hengqi@linux.alibaba.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent ff7c7d9f

drivers/net/virtio_net.c

+10 −1
Original line number Diff line number Diff line
@@ -411,6 +411,9 @@ struct virtnet_info { 
	/* Has control virtqueue */

	bool has_cvq;



	/* Lock to protect the control VQ */

	struct mutex cvq_lock;



	/* Host can handle any s/g split between our header and packet data */

	bool any_header_sg;
@@ -2675,6 +2678,7 @@ static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd 
	/* Caller should know better */

	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));



	mutex_lock(&vi->cvq_lock);

	vi->ctrl->status = ~0;

	vi->ctrl->hdr.class = class;

	vi->ctrl->hdr.cmd = cmd;
@@ -2697,11 +2701,12 @@ static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd 
	if (ret < 0) {

		dev_warn(&vi->vdev->dev,

			 "Failed to add sgs for command vq: %d\n.", ret);

		mutex_unlock(&vi->cvq_lock);

		return false;

	}



	if (unlikely(!virtqueue_kick(vi->cvq)))

		return vi->ctrl->status == VIRTIO_NET_OK;

		goto unlock;



	/* Spin for a response, the kick causes an ioport write, trapping

	 * into the hypervisor, so the request should be handled immediately.
@@ -2712,6 +2717,8 @@ static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd 
		cpu_relax();

	}



unlock:

	mutex_unlock(&vi->cvq_lock);

	return vi->ctrl->status == VIRTIO_NET_OK;

}
@@ -5736,6 +5743,8 @@ static int virtnet_probe(struct virtio_device *vdev) 
	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))

		vi->has_cvq = true;



	mutex_init(&vi->cvq_lock);



	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {

		mtu = virtio_cread16(vdev,

				     offsetof(struct virtio_net_config,