[v2,1/2] net/mlx5: cache the associated network device ifindex

  The associated device index is retrieved via Netlink request to
underlying Infiniband device driver. This network device index
is permanent throughout the lifetime of device. We do not
spawn the rte_eth_dev ports without associated network device, and
if network device is being unbound we get the remove notification
message and rte_eth_dev port is also detached. So, we may store
the ifindex in mlx5_device_spawn() routine at rte_eth_dev port
creation and initialization time and use the cached value further
instead of doing actual Netlink request.

Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
---
 drivers/net/mlx5/mlx5.c        |  7 +++++++
 drivers/net/mlx5/mlx5.h        |  1 +
 drivers/net/mlx5/mlx5_ethdev.c | 19 +++++++------------
 3 files changed, 15 insertions(+), 12 deletions(-)
  

> On Jul 21, 2019, at 7:56 AM, Viacheslav Ovsiienko <viacheslavo@mellanox.com> wrote:
> 
> The associated device index is retrieved via Netlink request to
> underlying Infiniband device driver. This network device index
> is permanent throughout the lifetime of device. We do not
> spawn the rte_eth_dev ports without associated network device, and
> if network device is being unbound we get the remove notification
> message and rte_eth_dev port is also detached. So, we may store
> the ifindex in mlx5_device_spawn() routine at rte_eth_dev port
> creation and initialization time and use the cached value further
> instead of doing actual Netlink request.
> 
> Reported-by: Stephen Hemminger <stephen@networkplumber.org>
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---

Acked-by: Yongseok Koh <yskoh@mellanox.com>

> drivers/net/mlx5/mlx5.c        |  7 +++++++
> drivers/net/mlx5/mlx5.h        |  1 +
> drivers/net/mlx5/mlx5_ethdev.c | 19 +++++++------------
> 3 files changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
> index 608daed..2f6254b 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -1630,6 +1630,13 @@ struct mlx5_dev_spawn_data {
> 		eth_dev->data->dev_flags |= RTE_ETH_DEV_REPRESENTOR;
> 		eth_dev->data->representor_id = priv->representor_id;
> 	}
> +	/*
> +	 * Store associated network device interface index. This index
> +	 * is permanent throughout the lifetime of device. So, we may store
> +	 * the ifindex here and use the cached value further.
> +	 */
> +	assert(spawn->ifindex);
> +	priv->if_index = spawn->ifindex;
> 	eth_dev->data->dev_private = priv;
> 	priv->dev_data = eth_dev->data;
> 	eth_dev->data->mac_addrs = priv->mac;
> diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
> index a73375a..1011dcc 100644
> --- a/drivers/net/mlx5/mlx5.h
> +++ b/drivers/net/mlx5/mlx5.h
> @@ -465,6 +465,7 @@ struct mlx5_priv {
> 	uint16_t domain_id; /* Switch domain identifier. */
> 	uint16_t vport_id; /* Associated VF vport index (if any). */
> 	int32_t representor_id; /* Port representor identifier. */
> +	unsigned int if_index; /* Associated kernel network device index. */
> 	/* RX/TX queues. */
> 	unsigned int rxqs_n; /* RX queues array size. */
> 	unsigned int txqs_n; /* TX queues array size. */
> diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
> index 6c9bcf1..dfd9e97 100644
> --- a/drivers/net/mlx5/mlx5_ethdev.c
> +++ b/drivers/net/mlx5/mlx5_ethdev.c
> @@ -225,10 +225,7 @@ struct ethtool_link_settings {
> 
> 	assert(priv);
> 	assert(priv->sh);
> -	ifindex = priv->nl_socket_rdma >= 0 ?
> -		  mlx5_nl_ifindex(priv->nl_socket_rdma,
> -				  priv->sh->ibdev_name,
> -				  priv->ibv_port) : 0;
> +	ifindex = mlx5_ifindex(dev);
> 	if (!ifindex) {
> 		if (!priv->representor)
> 			return mlx5_get_master_ifname(priv->sh->ibdev_path,
> @@ -299,14 +296,14 @@ struct ethtool_link_settings {
> unsigned int
> mlx5_ifindex(const struct rte_eth_dev *dev)
> {
> -	char ifname[IF_NAMESIZE];
> +	struct mlx5_priv *priv = dev->data->dev_private;
> 	unsigned int ifindex;
> 
> -	if (mlx5_get_ifname(dev, &ifname))
> -		return 0;
> -	ifindex = if_nametoindex(ifname);
> +	assert(priv);
> +	assert(priv->if_index);
> +	ifindex = priv->if_index;
> 	if (!ifindex)
> -		rte_errno = errno;
> +		rte_errno = ENXIO;
> 	return ifindex;
> }
> 
> @@ -641,7 +638,6 @@ struct ethtool_link_settings {
> 	struct mlx5_priv *priv = dev->data->dev_private;
> 	struct mlx5_dev_config *config = &priv->config;
> 	unsigned int max;
> -	char ifname[IF_NAMESIZE];
> 
> 	/* FIXME: we should ask the device for these values. */
> 	info->min_rx_bufsize = 32;
> @@ -662,8 +658,7 @@ struct ethtool_link_settings {
> 	info->rx_offload_capa = (mlx5_get_rx_port_offloads() |
> 				 info->rx_queue_offload_capa);
> 	info->tx_offload_capa = mlx5_get_tx_port_offloads(dev);
> -	if (mlx5_get_ifname(dev, &ifname) == 0)
> -		info->if_index = if_nametoindex(ifname);
> +	info->if_index = mlx5_ifindex(dev);
> 	info->reta_size = priv->reta_idx_n ?
> 		priv->reta_idx_n : config->ind_table_max_size;
> 	info->hash_key_size = MLX5_RSS_HASH_KEY_LEN;
> -- 
> 1.8.3.1
>