unsigned int nr_glist_frames, new_nr_glist_frames;
        unsigned int grefs_per_frame;
 
-       BUG_ON(gnttab_interface == NULL);
        grefs_per_frame = gnttab_interface->grefs_per_grant_frame;
 
        new_nr_grant_frames = nr_grant_frames + more_frames;
 
 static unsigned int nr_status_frames(unsigned int nr_grant_frames)
 {
-       BUG_ON(gnttab_interface == NULL);
        return gnttab_frames(nr_grant_frames, SPP);
 }
 
        int rc;
        unsigned int cur, extra;
 
-       BUG_ON(gnttab_interface == NULL);
        cur = nr_grant_frames;
        extra = ((req_entries + gnttab_interface->grefs_per_grant_frame - 1) /
                 gnttab_interface->grefs_per_grant_frame);
        /* Determine the maximum number of frames required for the
         * grant reference free list on the current hypervisor.
         */
-       BUG_ON(gnttab_interface == NULL);
        max_nr_glist_frames = (max_nr_grant_frames *
                               gnttab_interface->grefs_per_grant_frame / RPP);