IA32_MSR_MTRR_PHYSICAL_MASK_0
uint64 mask = x86_read_msr(IA32_MSR_MTRR_PHYSICAL_MASK_0 + index * 2);
x86_write_msr(IA32_MSR_MTRR_PHYSICAL_MASK_0 + index, 0);
x86_write_msr(IA32_MSR_MTRR_PHYSICAL_MASK_0 + index,