PSL_USERSET
tf->tf_rflags = PSL_USERSET;
tf->tf_eflags = PSL_USERSET;
tf->srr1 = PSL_MBO | PSL_USERSET | PSL_FE_DFLT;
#define PSL_USERSTATIC (PSL_USERSET | PSL_IP | 0x87c0008c)
tf->tf_ssr = PSL_USERSET;