lower_bits
unsigned long lower_bits = (phys_addr & PA_LOWER_BITS) >> PA_LOWER_BITS_SHIFT;
lower_bits ^= bp->lm; /* What bits are different? */
lower_bits = ~lower_bits; /* Invert. */
lower_bits |= bp->lk; /* What bits don't matter for matching? */
lower_bits = ~lower_bits; /* Invert. */
if (lower_bits)
unsigned int subfn = lower_bits(regs->cx, 32);
unsigned int fn = lower_bits(regs->ax, 32);
rax = lower_bits(regs->ax, bits);
regs->ax = lower_bits(ghcb->save.rax, bits);