Hi xuyanjie,

> -using vfio, use the following commands to load the vfio driver and bind it
> +using vfio, use the following commands to to load the vfio driver and bind it 

Seems that also here you need to rebase the patch against most recent code.
 
Change of "to to" => "to" was fixed by the following patch by me (from December 2018)
https://mails.dpdk.org/archives/dts/2018-December/004567.html 

Regards,
Rami Rosen