Subject: Re: [PATCH iwl-next 03/10] ixgbevf: use libeth in Rx processing

From: Simon Horman <[email-masked]>
Date: Tue, 24 Feb 2026 17:45:50 +0000

On Mon, Feb 23, 2026 at 10:52:10AM +0100, Larysa Zaremba wrote:
> Use page_pool buffers by the means of libeth in the Rx queues, this
> significantly reduces code complexity of the driver itself.
> 
> Suggested-by: Alexander Lobakin <[email-masked]>
> Reviewed-by: Alexander Lobakin <[email-masked]>
> Reviewed-by: Aleksandr Loktionov <[email-masked]>
> Signed-off-by: Larysa Zaremba <[email-masked]>

...

> @@ -3257,12 +3133,26 @@ static int ixgbevf_setup_all_tx_resources(struct ixgbevf_adapter *adapter)
>  int ixgbevf_setup_rx_resources(struct ixgbevf_adapter *adapter,
>  			       struct ixgbevf_ring *rx_ring)
>  {
> -	int size;
> +	struct libeth_fq fq = {
> +		.count		= rx_ring->count,
> +		.nid		= NUMA_NO_NODE,
> +		.type		= LIBETH_FQE_MTU,
> +		.xdp		= !!rx_ring->xdp_prog,
> +		.idx		= rx_ring->queue_index,
> +		.buf_len	= IXGBEVF_RX_PAGE_LEN(rx_ring->xdp_prog ?
> +						      LIBETH_XDP_HEADROOM :
> +						      LIBETH_SKB_HEADROOM),
> +	};
> +	int ret;
>  
> -	size = sizeof(struct ixgbevf_rx_buffer) * rx_ring->count;
> -	rx_ring->rx_buffer_info = vmalloc(size);
> -	if (!rx_ring->rx_buffer_info)
> -		goto err;
> +	ret = libeth_rx_fq_create(&fq, &rx_ring->q_vector->napi);
> +	if (ret)
> +		return ret;
> +
> +	rx_ring->pp = fq.pp;
> +	rx_ring->rx_fqes = fq.fqes;
> +	rx_ring->truesize = fq.truesize;
> +	rx_ring->rx_buf_len = fq.buf_len;
>  
>  	u64_stats_init(&rx_ring->syncp);
>  
> @@ -3270,25 +3160,29 @@ int ixgbevf_setup_rx_resources(struct ixgbevf_adapter *adapter,
>  	rx_ring->size = rx_ring->count * sizeof(union ixgbe_adv_rx_desc);
>  	rx_ring->size = ALIGN(rx_ring->size, 4096);
>  
> -	rx_ring->desc = dma_alloc_coherent(rx_ring->dev, rx_ring->size,
> +	rx_ring->desc = dma_alloc_coherent(fq.pp->p.dev, rx_ring->size,
>  					   &rx_ring->dma, GFP_KERNEL);
>  
>  	if (!rx_ring->desc)

Hi Larysa,

Prior to this patch, if this error condition was met,
then function would return -ENOMEM. But now it will return 0.
This does not seem intentional.

Flagged by Smatch.

>  		goto err;
>  
>  	/* XDP RX-queue info */
> -	if (xdp_rxq_info_reg(&rx_ring->xdp_rxq, adapter->netdev,
> -			     rx_ring->queue_index, 0) < 0)
> +	ret = __xdp_rxq_info_reg(&rx_ring->xdp_rxq, adapter->netdev,
> +				 rx_ring->queue_index, 0, rx_ring->truesize);
> +	if (ret)
>  		goto err;
>  
> +	xdp_rxq_info_attach_page_pool(&rx_ring->xdp_rxq, fq.pp);
> +
>  	rx_ring->xdp_prog = adapter->xdp_prog;
>  
>  	return 0;
>  err:
> -	vfree(rx_ring->rx_buffer_info);
> -	rx_ring->rx_buffer_info = NULL;
> +	libeth_rx_fq_destroy(&fq);
> +	rx_ring->rx_fqes = NULL;
> +	rx_ring->pp = NULL;
>  	dev_err(rx_ring->dev, "Unable to allocate memory for the Rx descriptor ring\n");
> -	return -ENOMEM;
> +	return ret;
>  }
>  
>  /**

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