XEN_RUNSTATE_UPDATE
BUILD_BUG_ON((XEN_RUNSTATE_UPDATE >> 56) != 0x80);
entry_time |= XEN_RUNSTATE_UPDATE;
*update_bit = (vx->runstate_entry_time | XEN_RUNSTATE_UPDATE) >> 56;
entry_time &= ~XEN_RUNSTATE_UPDATE;
(state_time & XEN_RUNSTATE_UPDATE));