[PATCH] net/vhost: add flag to control wait queuing

[Ling, WeiX]

> -----Original Message-----
> From: Yuan Wang <yuanx.wang at intel.com>
> Sent: Wednesday, June 1, 2022 10:26 PM
> To: maxime.coquelin at redhat.com; Xia, Chenbo <chenbo.xia at intel.com>;
> dev at dpdk.org
> Cc: Hu, Jiayu <jiayu.hu at intel.com>; He, Xingguang
> <xingguang.he at intel.com>; Wang, YuanX <yuanx.wang at intel.com>;
> stable at dpdk.org
> Subject: [PATCH] net/vhost: add flag to control wait queuing
>
> update_queuing_status prevents PMD queue operations from affecting the
> data plane by waiting for rx/tx_pkt_burst to stops accessing the vhost device.
> In fact, it is only necessary to wait when destroy/stop the device, new/start
> device and vring_state_changed cases do not need.
>
> Since vring is locked when vring state changes, unconditional waiting may
> also cause deadlocks.
>
> To avoid deadlocks and unnecessary waiting, this patch adds a flag to control
> whether waiting is required.
>
> Fixes: 9dc6bb0682 (net/vhost: fix access to freed memory)
> Fixes: 1ce3c7fe14 (net/vhost: emulate device start/stop behavior)
> Cc: stable at dpdk.org
>
> Signed-off-by: Yuan Wang <yuanx.wang at intel.com>
> ---

Tested-by: Wei Ling <weix.ling at intel.com>