MSR_DELTA_MASK
assert((msr & MSR_DELTA_MASK) == 0);
else if ((sc->msr & MSR_DELTA_MASK) != 0 && (sc->ier & IER_EMSC) != 0)
sc->msr &= MSR_DELTA_MASK;
sc->msr &= ~MSR_DELTA_MASK;