Re: [PATCH] vdpa/ifc: fix reconnetion issue in SW assisted live migration

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

On 12/12/22 08:12, Andy Pei wrote:
> In the case using argument "sw-live-migration=1" to enable SW assisted live
> migration, we take QEMU as front end for example, after source VM migrates
> to destination VM, we keep vdpa process for source VM there, we kill the
> QEMU process for source VM, and restart the QEMU process for source VM.
> In this case, vdpa driver will not perform DMA map and data path will not
> work properly.
> 
> The above case works fine in the case "sw-live-migration=0".
> 
> The root cause is that current code driver does not set running flag to 0.
> Driver treats device as ruuning and does not perform DMA map.
> 
> Fixes: 4bb531e152d3 ("net/ifc: support SW assisted VDPA live migration")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Andy Pei <andy.pei@intel.com>
> ---
>   drivers/vdpa/ifc/ifcvf_vdpa.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/vdpa/ifc/ifcvf_vdpa.c b/drivers/vdpa/ifc/ifcvf_vdpa.c
> index 49d68ad..dc8600d 100644
> --- a/drivers/vdpa/ifc/ifcvf_vdpa.c
> +++ b/drivers/vdpa/ifc/ifcvf_vdpa.c
> @@ -1044,6 +1044,8 @@ struct rte_vdpa_dev_info {
>   
>   	vdpa_disable_vfio_intr(internal);
>   
> +	rte_atomic32_set(&internal->running, 0);
> +
>   	ret = rte_vhost_host_notifier_ctrl(vid, RTE_VHOST_QUEUE_ALL, false);
>   	if (ret && ret != -ENOTSUP)
>   		goto error;

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

Thanks,
Maxime