[PATCH] net/vhost: support queue info query

[Liangxing Wang]

Kindly ping for review. Thanks.

> -----Original Message-----
> From: Liangxing Wang <wangliangxing at hygon.cn>
> Sent: 2026年7月1日 14:14
> To: maxime.coquelin at redhat.com; chenbox at nvidia.com
> Cc: dev at dpdk.org; Liangxing Wang <wangliangxing at hygon.cn>
> Subject: [PATCH] net/vhost: support queue info query
> 
> Add Rx and Tx queue info callbacks to report the vhost-user vring size as the
> queue descriptor number.
> 
> The vhost-user PMD does not use the descriptor count passed by
> rte_eth_rx_queue_setup() and rte_eth_tx_queue_setup(). The actual queue
> depth is negotiated with the virtio frontend and maintained by the vhost
> library. Query the vhost vring and report its size through rxq_info_get and
> txq_info_get.
> 
> With this change, testpmd using vhost-user PMD can display the correct Rx and
> Tx queue descriptor number in the port start log.
> 
> Signed-off-by: Liangxing Wang <wangliangxing at hygon.cn>
> ---
>  drivers/net/vhost/rte_eth_vhost.c | 38 +++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/net/vhost/rte_eth_vhost.c
> b/drivers/net/vhost/rte_eth_vhost.c
> index 05940f2461..af023c7639 100644
> --- a/drivers/net/vhost/rte_eth_vhost.c
> +++ b/drivers/net/vhost/rte_eth_vhost.c
> @@ -1480,12 +1480,50 @@ vhost_dev_priv_dump(struct rte_eth_dev *dev,
> FILE *f)
>  	return 0;
>  }
> 
> +static void
> +eth_rxq_info_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
> +		 struct rte_eth_rxq_info *qinfo)
> +{
> +	struct rte_vhost_vring vring;
> +	struct vhost_queue *vq = dev->data->rx_queues[rx_queue_id];
> +
> +	qinfo->nb_desc = 0;
> +
> +	if (vq == NULL || vq->vid < 0)
> +		return;
> +
> +	if (rte_vhost_get_vhost_vring(vq->vid, vq->virtqueue_id, &vring) < 0)
> +		return;
> +
> +	qinfo->nb_desc = vring.size;
> +}
> +
> +static void
> +eth_txq_info_get(struct rte_eth_dev *dev, uint16_t tx_queue_id,
> +		 struct rte_eth_txq_info *qinfo)
> +{
> +	struct rte_vhost_vring vring;
> +	struct vhost_queue *vq = dev->data->tx_queues[tx_queue_id];
> +
> +	qinfo->nb_desc = 0;
> +
> +	if (vq == NULL || vq->vid < 0)
> +		return;
> +
> +	if (rte_vhost_get_vhost_vring(vq->vid, vq->virtqueue_id, &vring) < 0)
> +		return;
> +
> +	qinfo->nb_desc = vring.size;
> +}
> +
>  static const struct eth_dev_ops ops = {
>  	.dev_start = eth_dev_start,
>  	.dev_stop = eth_dev_stop,
>  	.dev_close = eth_dev_close,
>  	.dev_configure = eth_dev_configure,
>  	.dev_infos_get = eth_dev_info,
> +	.rxq_info_get = eth_rxq_info_get,
> +	.txq_info_get = eth_txq_info_get,
>  	.rx_queue_setup = eth_rx_queue_setup,
>  	.tx_queue_setup = eth_tx_queue_setup,
>  	.rx_queue_release = eth_rx_queue_release,
> --
> 2.43.0