Obviously the stuff in space and on Mars was videoed by SM (Olympus Scacefliks not sure which lens aperture) and all the stuff at mission control was pure CGI.
In 20 years when they make the film will we be picking people out cause we vaguely remember original footage like with the Apollo stuff.
If you mean how much is "artist's impression"-style computer graphics and not shot footage, it's a fairly safe bet that the answer is "everything that wasn't from a camera on the surface of the Earth", so all the rocket/lander footage after the rocket had reached 150m or so; I'm pretty sure it's not pragmatically possible to film a rocket taking off from the air nearby as they close the surrounding airspace. You often see footage shot from cameras mounted on the rocket itself, though.
Since the Spirit rover made it to Mars and spent nearly five and a half years roaming around, poking rocks and taking photos, none of it was simulation in the "let's see if this is possible" sense! ;-)