Duramax lb7 white smoke and shaking
 

Yesterday I got home and parked my truck in the driveway but before I shut the engine down she was shaking bad and I noticed a large amount of white smoke blasting through the blow-by. I popped the hood and the whole engine was shaking left and right. There is also white smoke blowing out of the exhaust. The smoke is hard to see out of the exhaust but not the blow by. What is the problem?