[PATCH v2 2/2] vhost: fix slot index calculation in async vhost

[Ling, WeiX]

> -----Original Message-----
> From: Cheng Jiang <cheng1.jiang at intel.com>
> Sent: Tuesday, October 11, 2022 11:08 AM
> To: maxime.coquelin at redhat.com; Xia, Chenbo <chenbo.xia at intel.com>
> Cc: dev at dpdk.org; Hu, Jiayu <jiayu.hu at intel.com>; Ding, Xuan
> <xuan.ding at intel.com>; Ma, WenwuX <wenwux.ma at intel.com>; Wang,
> YuanX <yuanx.wang at intel.com>; Yang, YvonneX
> <yvonnex.yang at intel.com>; He, Xingguang <xingguang.he at intel.com>;
> Jiang, Cheng1 <cheng1.jiang at intel.com>; stable at dpdk.org
> Subject: [PATCH v2 2/2] vhost: fix slot index calculation in async vhost
>
> When the packet receiving failure and the DMA ring full occur simultaneously
> in the asynchronous vhost, the slot_idx needs to be decreased by 1. For
> packed virtqueue, the slot index should be ring_size - 1, if the slot_idx is
> currently 0, since the ring size is not necessarily the power of 2.
>
> Fixes: 84d5204310d7 ("vhost: support async dequeue for split ring")
> Fixes: fe8477ebbd94 ("vhost: support async packed ring dequeue")
> Cc: stable at dpdk.org
>
> Signed-off-by: Cheng Jiang <cheng1.jiang at intel.com>
> ---
Tested-by: Wei Ling <weix.ling at intel.com>