Re: [PATCH] net/af_xdp: add rx/tx queue support for af_xdp

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 18 Jun 2025 17:41:03 +0000
Shivaji Kant <shivajikant@google.com> wrote:

> Driver like GVE do support rx/tx queue configuration
> rather than combined queue. Enable AF_XDP vdev to use
> rx/tx queue configuration instead of combined queue
> configuration if available.

The first sentence is awkward to read.

Is there anything about queues in the driver documentation?

> 
> Signed-off-by: Shivaji Kant <shivajikant@google.com>
> Reviewed-by: Joshua Washington <joshwash@google.com>
> ---
>  .mailmap                            |  1 +
>  drivers/net/af_xdp/rte_eth_af_xdp.c | 30 ++++++++++++++++++-----------
>  2 files changed, 20 insertions(+), 11 deletions(-)
> 
> diff --git a/.mailmap b/.mailmap
> index 8483d96ec5..c67caa7c9d 100644
> --- a/.mailmap
> +++ b/.mailmap
> @@ -1423,6 +1423,7 @@ Shijith Thotton <sthotton@marvell.com> <shijith.thotton@caviumnetworks.com>
>  Shiqi Liu <835703180@qq.com>
>  Shiri Kuzin <shirik@nvidia.com> <shirik@mellanox.com>
>  Shivah Shankar S <sshankarnara@marvell.com>
> +Shivaji Kant <shivajikant@google.com>
>  Shivanshu Shukla <shivanshu.shukla@intel.com>
>  Shiweixian <shiweixian@huawei.com>
>  Shiyang He <shiyangx.he@intel.com>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 05115150a7..6899b6b165 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -168,7 +168,7 @@ struct pmd_internals {
>  	int start_queue_idx;
>  	int queue_cnt;
>  	int max_queue_cnt;
> -	int combined_queue_cnt;
> +	int configured_queue_cnt;
>  	bool shared_umem;
>  	char prog_path[PATH_MAX];
>  	bool custom_prog_configured;
> @@ -2043,11 +2043,11 @@ parse_prog_arg(const char *key __rte_unused,
>  
>  static int
>  xdp_get_channels_info(const char *if_name, int *max_queues,
> -				int *combined_queues)
> +				int *configured_queues)
>  {
>  	struct ethtool_channels channels;
>  	struct ifreq ifr;
> -	int fd, ret;
> +	int fd, ret, rxtx_q_count;
>  
>  	fd = socket(AF_INET, SOCK_DGRAM, 0);
>  	if (fd < 0)
> @@ -2066,15 +2066,23 @@ xdp_get_channels_info(const char *if_name, int *max_queues,
>  		}
>  	}
>  
> -	if (channels.max_combined == 0 || errno == EOPNOTSUPP) {
> +	/* For dirvers with rx/tx queue configured */

Spelling errors.

> +	rxtx_q_count = RTE_MIN(channels.rx_count, channels.tx_count);
> +
> +	if ((channels.max_combined == 0 && rxtx_q_count == 0) || errno == EOPNOTSUPP) {
>  		/* If the device says it has no channels, then all traffic
>  		 * is sent to a single stream, so max queues = 1.
>  		 */
>  		*max_queues = 1;
> -		*combined_queues = 1;
> -	} else {
> +		*configured_queues = 1;
> +	} else if (channels.max_combined > 0) {
>  		*max_queues = channels.max_combined;
> -		*combined_queues = channels.combined_count;
> +		*configured_queues = channels.combined_count;
> +		AF_XDP_LOG_LINE(INFO, "Using Combined queues configuration");
> +	} else {
> +		*max_queues = RTE_MIN(channels.max_rx, channels.max_tx);
> +		*configured_queues = rxtx_q_count;
> +		AF_XDP_LOG_LINE(INFO, "Using Rx/Tx queues configuration");
>  	}
>  
>   out:
> @@ -2215,15 +2223,15 @@ init_internals(struct rte_vdev_device *dev, const char *if_name,
>  	strlcpy(internals->dp_path, dp_path, PATH_MAX);
>  
>  	if (xdp_get_channels_info(if_name, &internals->max_queue_cnt,
> -				  &internals->combined_queue_cnt)) {
> +				  &internals->configured_queue_cnt)) {
>  		AF_XDP_LOG_LINE(ERR, "Failed to get channel info of interface: %s",
>  				if_name);
>  		goto err_free_internals;
>  	}
>  
> -	if (queue_cnt > internals->combined_queue_cnt) {
> -		AF_XDP_LOG_LINE(ERR, "Specified queue count %d is larger than combined queue count %d.",
> -				queue_cnt, internals->combined_queue_cnt);
> +	if (queue_cnt > internals->configured_queue_cnt) {
> +		AF_XDP_LOG_LINE(ERR, "Specified queue count %d is larger than configured queue count %d.",
> +				queue_cnt, internals->configured_queue_cnt);
>  		goto err_free_internals;
>  	}
>