Additionally, Virginia state law allows bar and restaurant owners to ban weapons from the premises, as long as they prominently display a gun-free sign in the establishment. However, “No Firearm” signs in Virginia do not carry the force of law unless the property is specifically mentioned in state law as off limits to individuals with a permit or license to carry.
http://www.huffingtonpost.com/2013/12/27/toby-keith-restaurant-guns_n_4509745.html?ncid=edlinkusaolp00000009
Seems to be a loophole here, now, what management can do is ask them to leave for another reason and if they refuse, then they can be cited for trespassing.