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

Larysa Zaremba
2026-02-25T17:20:09Z

On Tue, Feb 24, 2026 at 05:45:50PM +0000, Simon Horman wrote:
> 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 <aleksander.lobakin@intel.com>
> > Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
> > Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
>
> ...
>
> > @@ -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.

No, it is not intentional, though the problem is fixed in a later patch. Will
correct this one in v2.

>
> > 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;
> > }
> >
> > /**
>
> ...