require_extension('S');
if (STATE.v) {
  if (STATE.prv == PRV_U || get_field(STATE.hstatus, HSTATUS_VTVM))
    require_novirt();
} else {
  require_privilege(get_field(STATE.mstatus, MSTATUS_TVM) ? PRV_M : PRV_S);
}
MMU.flush_tlb();