I read Using a Controller or Android Phone for Motion or Touch Input on wiki and it refered to How to setup your input software to provide motion sensor data on sshnuke, but didn’t find info about how to get motion control on linux.
I used Win7 and DS4Windows and enjoyed motion control with cemuhookudp. I researched about how to do it on Linux, and found TheDrHax/ds4drv-cemuhook(a fork from ds4drv) that can make DS4 and CemuhookUDP work on Linux.
I tested with Citra Nightly 1584 and it worked fine. (although there was some troubles when setting control configuration)
I don’t know how to submit this info on sshnuke so I put it here in order to help whom wants to use Citra on Linux and needs DS4 motion control.