[PATCH v7 26/26] virtio_net: support set_ringparam

[Xuan Zhuo]

On Wed, 9 Mar 2022 17:29:28 +0800, Jason Wang <jasowang at redhat.com> wrote:
>
> 在 2022/3/8 下午8:35, Xuan Zhuo 写道:
> > Support set_ringparam based on virtio queue reset.
> >
> > The rx,tx_pending required to be passed must be power of 2.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> > ---
> >   drivers/net/virtio_net.c | 47 ++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 47 insertions(+)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index f1bdc6ce21c3..1fa2d632a994 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -2290,6 +2290,52 @@ static void virtnet_get_ringparam(struct net_device *dev,
> >   	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
> >   }
> >
> > +static int virtnet_set_ringparam(struct net_device *dev,
> > +				 struct ethtool_ringparam *ring,
> > +				 struct kernel_ethtool_ringparam *kernel_ring,
> > +				 struct netlink_ext_ack *extack)
> > +{
> > +	struct virtnet_info *vi = netdev_priv(dev);
> > +	u32 rx_pending, tx_pending;
> > +	struct receive_queue *rq;
> > +	struct send_queue *sq;
> > +	int i, err;
> > +
> > +	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
> > +		return -EINVAL;
>
>
> Any chance that we may hit this EINVAL?

This is definitely not the case at present.

I think this can be kept, this makes sense.

I can remove it in the next version if you think it should be removed.

Thanks.

>
> Thanks
>
>
> > +
> > +	rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
> > +	tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
> > +
> > +	if (ring->rx_pending == rx_pending &&
> > +	    ring->tx_pending == tx_pending)
> > +		return 0;
> > +
> > +	if (ring->rx_pending > virtqueue_get_vring_max_size(vi->rq[0].vq))
> > +		return -EINVAL;
> > +
> > +	if (ring->tx_pending > virtqueue_get_vring_max_size(vi->sq[0].vq))
> > +		return -EINVAL;
> > +
> > +	for (i = 0; i < vi->max_queue_pairs; i++) {
> > +		rq = vi->rq + i;
> > +		sq = vi->sq + i;
> > +
> > +		if (ring->tx_pending != tx_pending) {
> > +			err = virtnet_tx_vq_reset(vi, sq, ring->tx_pending);
> > +			if (err)
> > +				return err;
> > +		}
> > +
> > +		if (ring->rx_pending != rx_pending) {
> > +			err = virtnet_rx_vq_reset(vi, rq, ring->rx_pending);
> > +			if (err)
> > +				return err;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> >
> >   static void virtnet_get_drvinfo(struct net_device *dev,
> >   				struct ethtool_drvinfo *info)
> > @@ -2523,6 +2569,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
> >   	.get_drvinfo = virtnet_get_drvinfo,
> >   	.get_link = ethtool_op_get_link,
> >   	.get_ringparam = virtnet_get_ringparam,
> > +	.set_ringparam = virtnet_set_ringparam,
> >   	.get_strings = virtnet_get_strings,
> >   	.get_sset_count = virtnet_get_sset_count,
> >   	.get_ethtool_stats = virtnet_get_ethtool_stats,
>