TECHNICALLY none (except possibly some differences training on the c/s prop).
Your SEP (Land) Class Rating entitles you to fly ANY aeroplane in the Single Engine Piston (Land) class.
Of course to jump into a Cirrus and attempt to fly it having only ever flown a Cessna 172 would be very stupid.
Realistically you would need a few hours conversion onto type - a Cirrus is a 'lot more aeroplane' than a Cessna 172.