Re: [dpdk-dev] [PATCH v5 6/7] ethdev: add API to retrieve multiple ethernet addresses

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 10/7/21 2:27 PM, Konstantin Ananyev wrote:
> Introduce rte_eth_macaddrs_get() to allow user to retrieve all ethernet
> addresses assigned to given port.
> Change testpmd to use this new function and avoid referencing directly
> rte_eth_devices[].
> 
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

[snip]

> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index 9f7a0cbb8c..83b57a7524 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -3573,6 +3573,31 @@ rte_eth_dev_set_ptypes(uint16_t port_id, uint32_t ptype_mask,
>  	return ret;
>  }
>  
> +int
> +rte_eth_macaddrs_get(uint16_t port_id, struct rte_ether_addr ma[], uint32_t num)

Do we really need fixed size type in the case of num?
Shouldn't it be just 'unsigned int' as the default choice for
a number of elements?

> +{
> +	int32_t ret;
> +	struct rte_eth_dev *dev;
> +	struct rte_eth_dev_info dev_info;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +	dev = &rte_eth_devices[port_id];
> +
> +	ret = rte_eth_dev_info_get(port_id, &dev_info);
> +	if (ret != 0)
> +		return ret;

In theory we can rely on port_id check in
rte_eth_dev_info_get() on success to avoid duplicate checks.
I'd do it and just highlight it in a comment.

> +
> +	if (ma == NULL) {
> +		RTE_ETHDEV_LOG(ERR, "%s: invalid parameters\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	num = RTE_MIN(dev_info.max_mac_addrs, num);
> +	memcpy(ma, dev->data->mac_addrs, num * sizeof(ma[0]));
> +
> +	return num;
> +}
> +
>  int
>  rte_eth_macaddr_get(uint16_t port_id, struct rte_ether_addr *mac_addr)
>  {
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index c0e1a40681..77314ecf24 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -3037,6 +3037,27 @@ int rte_eth_dev_set_rx_queue_stats_mapping(uint16_t port_id,
>   */
>  int rte_eth_macaddr_get(uint16_t port_id, struct rte_ether_addr *mac_addr);
>  
> +/**
> + * Retrieve the Ethernet addresses of an Ethernet device.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param ma
> + *   A pointer to an array of structures of type *ether_addr* to be filled with
> + *   the Ethernet addresses of the Ethernet device.
> + * @param num
> + *   Number of elements in the *ma* array.

*ma* -> @p ma

> + *   Note that  rte_eth_dev_info::max_mac_addrs can be used to retrieve
> + *   max number of Ethernet addresses for given port.
> + * @return
> + *   - number of retrieved addresses if successful
> + *   - (-ENODEV) if *port_id* invalid.
> + *   - (-EINVAL) if bad parameter.
> + */
> +__rte_experimental
> +int rte_eth_macaddrs_get(uint16_t port_id, struct rte_ether_addr *ma,
> +	uint32_t num);
> +
>  /**
>   * Retrieve the contextual information of an Ethernet device.
>   *
> diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
> index 79e62dcf61..2bad712958 100644
> --- a/lib/ethdev/version.map
> +++ b/lib/ethdev/version.map
> @@ -250,6 +250,9 @@ EXPERIMENTAL {
>  	rte_mtr_meter_policy_delete;
>  	rte_mtr_meter_policy_update;
>  	rte_mtr_meter_policy_validate;
> +
> +	# added in 21.11
> +	rte_eth_macaddrs_get;
>  };
>  
>  INTERNAL {
>