Diddy and Suge Knight will not reignite the East Coast-West Coast war over the new Tupac biopic -- in fact, Death Row and Bad Boy finally agree on something.

Production sources on "All Eyez on Me" tell us ... producer L.T. Hutton reached out to both moguls about how they're portrayed in the film, and to get their thoughts on the story. We're told Diddy loved it so much he gave his blessing for Biggie's "Who Shot Ya?" to be used on the soundtrack.

We're told Suge wasn't able to watch the movie due to his situation -- sitting in jail awaiting trial for murder -- but lawyers did, and described it to him. Suge gave it his stamp of approval, mostly because he goes way back with Hutton and trusts him.

Think about it ... if Diddy signs off on a movie that includes "Hit 'Em Up," it's gotta be good! Right?