KVM: VMX: mark unusable segment as nonpresent

	var->limit = vmx_read_guest_seg_limit(vmx, seg);

	var->selector = vmx_read_guest_seg_selector(vmx, seg);

	ar = vmx_read_guest_seg_ar(vmx, seg);

	var->unusable = (ar >> 16) & 1;

	var->type = ar & 15;

	var->s = (ar >> 4) & 1;

	var->dpl = (ar >> 5) & 3;

	var->present = (ar >> 7) & 1;

	/*

	 * Some userspaces do not preserve unusable property. Since usable

	 * segment has to be present according to VMX spec we can use present

	 * property to amend userspace bug by making unusable segment always

	 * nonpresent. vmx_segment_access_rights() already marks nonpresent

	 * segment as unusable.

	 */

	var->present = !var->unusable;

	var->avl = (ar >> 12) & 1;

	var->l = (ar >> 13) & 1;

	var->db = (ar >> 14) & 1;

	var->g = (ar >> 15) & 1;

	var->unusable = (ar >> 16) & 1;

}

static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)