Re: [PATCH net-next v8 06/16] net: Proxy net_mp_{open,close}_rxq for leased queues

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 29 Jan 2026 23:28:20 +0100 Daniel Borkmann wrote:
> @@ -191,24 +214,15 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
>  }
>  EXPORT_SYMBOL_NS_GPL(netdev_rx_queue_restart, "NETDEV_INTERNAL");
>  
> -int net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,
> -		    const struct pp_memory_provider_params *p,
> -		    struct netlink_ext_ack *extack)
> +static int __net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,
> +			     const struct pp_memory_provider_params *p,
> +			     struct netlink_ext_ack *extack)
>  {
>  	const struct netdev_queue_mgmt_ops *qops = dev->queue_mgmt_ops;
>  	struct netdev_queue_config qcfg[2];
>  	struct netdev_rx_queue *rxq;
>  	int ret;
>  
> -	if (!netdev_need_ops_lock(dev))
> -		return -EOPNOTSUPP;
> -
> -	if (rxq_idx >= dev->real_num_rx_queues) {
> -		NL_SET_ERR_MSG(extack, "rx queue index out of range");
> -		return -ERANGE;
> -	}
> -	rxq_idx = array_index_nospec(rxq_idx, dev->real_num_rx_queues);
> -

> +int net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,
> +		    const struct pp_memory_provider_params *p,
> +		    struct netlink_ext_ack *extack)
> +{
> +	struct net_device *orig_dev = dev;
> +	int ret;
> +
> +	if (!netdev_need_ops_lock(dev))
> +		return -EOPNOTSUPP;
> +
> +	if (rxq_idx >= dev->real_num_rx_queues) {
> +		NL_SET_ERR_MSG(extack, "rx queue index out of range");
> +		return -ERANGE;
> +	}
> +

nit: delete this empty line please, like it was in the original code.

> +	rxq_idx = array_index_nospec(rxq_idx, dev->real_num_rx_queues);
> +
> +	if (!netif_get_rx_queue_lease_locked(&dev, &rxq_idx)) {
> +		NL_SET_ERR_MSG(extack, "rx queue leased to a virtual netdev");
> +		return -EBUSY;
> +	}
> +	if (!dev->dev.parent) {
> +		NL_SET_ERR_MSG(extack, "rx queue belongs to a virtual netdev");
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}
> +
> +	ret = __net_mp_open_rxq(dev, rxq_idx, p, extack);
> +out:
> +	netif_put_rx_queue_lease_locked(orig_dev, dev);
> +	return ret;

Please:

	if (!netif_queue_is_a_lease())
		return __net_mp_open_rxq(dev, rxq_idx, p, extack);

	..explicit code that deals with the lease, no conditional locking
	...
	ret = __net_mp_open_rxq($dev, $rxq_idx, p, extack);
	...


> -	rxq = __netif_get_rx_queue(dev, ifq_idx);
> +	rxq = __netif_get_rx_queue(dev, rxq_idx);

Indeed good to cleanup the ifq_idx naming that sneaked in, but IDK if
this belongs in this commit :S