Download: https://github.com/xerpi/ds3vita/releases

Enable the plugin:

1. Add ds3vita.skprx to taiHEN's config (ux0:/tai/config.txt):

   *KERNEL
   ux0:tai/ds3vita.skprx
   

2. You need to refresh the config.txt by rebooting or through VitaShell.

Pairing the controller:

1. Download this tool (or this other one if you want to compile it yourself)
2. Connect your DS3 to the PC and open the tool
3. Introduce the Vita's MAC address plus 1 to the tool (Settings -> System -> System information)

Using it once paired (see above):

1. Just press the PS button and it will connect to the Vita

Note: If you use Mai, don't put the plugin inside ux0:/plugins because Mai will load all stuff you put in there...