Christy Mack -- Doing AVN Party ... But Not For the Porn Of It

Porn star Christy Mack is taking her talents to Vegas for the AVN Awards -- but after recovering from a brutal domestic violence attack ... she's doing it for a charitable cause.

TMZ has learned Mack will be doing a meet and greet at OG Las Vegas on Friday night -- and a portion of the door proceeds will be donated to Safe Nest -- a domestic violence org.

Christy's appearance kicks off AVN weekend in Vegas ... and we're told there will be VIP gift bags with limited edition Christy Mack merchandise on sale to fans. Some of that revenue will also go to Safe Nest.

TMZ broke the story ... Mack was allegedly pummeled by her ex-boyfriend War Machine back in August ... leaving her with broken bones and a ruptured liver.

War Machine is still behind bars facing 32 charges ... including attempted murder.