PSL_USERSRR1
tf->tf_srr1 &= (PSL_USERSRR1|PSL_FP|PSL_VEC);
utf->srr1 = tf->tf_srr1 & PSL_USERSRR1;
register_t msr = tf->tf_srr1 & PSL_USERSRR1;
gr[_REG_MSR] = tf->tf_srr1 & PSL_USERSRR1;
linux_regs.lmsr = tf->tf_srr1 & PSL_USERSRR1;