Re: [PATCH] net/virtio: fix incorrect slots number when indirect feature on

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 1/20/22 13:22, Marvin Liu wrote:
> Virtio driver only occupies one slot for enqueuing chained mbufs when
> indirect feature is on. Required slots calculation should depend on
> indirect feature status at the end.
> 
> Fixes: 0eaf7fc2fe8e ("net/virtio: separate AVX Rx/Tx")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>
> 
> diff --git a/drivers/net/virtio/virtio_rxtx_packed.h b/drivers/net/virtio/virtio_rxtx_packed.h
> index d5c259a1f6..536112983c 100644
> --- a/drivers/net/virtio/virtio_rxtx_packed.h
> +++ b/drivers/net/virtio/virtio_rxtx_packed.h
> @@ -125,13 +125,12 @@ virtqueue_enqueue_single_packed_vec(struct virtnet_tx *txvq,
>   	 * any_layout => number of segments
>   	 * default    => number of segments + 1
>   	 */
> -	slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
>   	can_push = rte_mbuf_refcnt_read(txm) == 1 &&
>   		   RTE_MBUF_DIRECT(txm) &&
>   		   txm->nb_segs == 1 &&
>   		   rte_pktmbuf_headroom(txm) >= hdr_size;
>   
> -	slots = txm->nb_segs + !can_push;
> +	slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
>   	need = slots - vq->vq_free_cnt;
>   
>   	/* Positive value indicates it need free vring descriptors */

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime