For starters ensure the oil is now at the right level.

Next steam clean the engine to remove all the oil that has sprayed out.

I would then take all of the pipe work off around the dump valve etc.

and clean it all out including the valve.

You may have been lucky and you might be ok, but over filling will mean that you will get a build up of pressure which as you have seen not only causes oil to blow out over the engine but may breached the seals in various places such as the sump gasket.

If you are getting smoke this could be what has happened and since you were driving the car hard, the pressure will have built up by a fair amount.

If you're lucky it might be excess oil burning away from places where it shouldn't be.

You are probably lucky in the fact that you have sorted the situation quickly, so you may get away with your error, just don't do it again!