V_IRQ
ctrl->v_irq &= ~V_IRQ;
if ((ctrl->v_irq & V_IRQ) != 0 && ctrl->v_intr_vector == 0) {
ctrl->v_irq |= V_IRQ;
if ((ctrl->v_irq & V_IRQ) == 0 && ctrl->v_intr_vector == 0) {