The Ivy -- world-famous for drawing in celebs from Jennifer Lopez and Sofia Vergara to Rob Lowe and Magic Johnson -- got a frightening call from a man yelling homophobic slurs and threatening to blow up the joint ... and cops are investigating.
According to legal docs obtained by TMZ ... the call came 4 days before Christmas when a man said, "You're all pieces of shit, all of you are trash." The maitre d' asked the caller how he could help him, and the man replied, "You're all a bunch of fudge packers, I'm going to blow you all up."
The employee jotted down the guy's number, thanks to caller ID, and called cops to report the incident. LAPD got a search warrant to track down the suspect.
Cops are on the hunt for the culprit.