[dpdk-stable] [PATCH] net/virtio: fix incorrect avail desc id

[Maxime Coquelin]

On 10/21/21 16:25, xuan.ding at intel.com wrote:
> From: Xuan Ding <xuan.ding at intel.com>
> 
> Vhost will update desc’s Buffer ID advance to next used descriptor when
> VIRTIO_F_IN_ORDER feature negotiated. When virtio reuses the descriptor,
> the Buffer ID should be restored even VIRTQ_DESC_F_INDIRECT
> feature negotiated.
> 
> Fixes: b473061b0e1d ("net/virtio: fix indirect descriptors in packed datapaths")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Xuan Ding <xuan.ding at intel.com>
> Signed-off-by: Yong Liu <yong.liu at intel.com>
> Signed-off-by: Miao Li <miao.li at intel.com>
> ---
>   drivers/net/virtio/virtqueue.h | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
> index d0c48ca415..5259a6f814 100644
> --- a/drivers/net/virtio/virtqueue.h
> +++ b/drivers/net/virtio/virtqueue.h
> @@ -709,6 +709,9 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
>   			RTE_PTR_DIFF(&txr[idx].tx_packed_indir, txr);
>   		start_dp[idx].len   = (seg_num + 1) *
>   			sizeof(struct vring_packed_desc);
> +		/* Packed descriptor id needs to be restored when inorder. */
> +		if (in_order)
> +			start_dp[idx].id = idx;
>   		/* reset flags for indirect desc */
>   		head_flags = VRING_DESC_F_INDIRECT;
>   		head_flags |= vq->vq_packed.cached_flags;
> 

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

Thanks,
Maxime