$22 big draw itm vs chip leader

[qwertyui9]

Villain has not been playing aggressively preflop prefferring to limp in to a lot of hands. Have seen him make a couple of small raises preflop, once with AK and another with JJ
He has called my blind when folded to him in the last 4 rounds and we've had no real confrontations.

Button: 2.5k
Villain (sb): 9.5k
Hero (bb): 6k has A [img]/images/graemlins/heart.gif[/img] 5 [img]/images/graemlins/heart.gif[/img]

Action (Blinds are 200/400):
Button folds
Villain raises t800
Hero calls

Flop: 10[img]/images/graemlins/heart.gif[/img] 5 [img]/images/graemlins/spade.gif[/img] 4 [img]/images/graemlins/heart.gif[/img] (pot t1600)

Villain moves all in
Hero?