rdmsr from userspace
Rui Paulo
rpaulo at FreeBSD.org
Sat May 17 16:05:26 UTC 2008
Andriy Gapon wrote:
>
> It seems that rdmsr instruction can be executed only at the highest
> privilege level and thus is not permitted from userland. Maybe we should
> provide something like Linux /dev/cpu/msr?
> I don't like interface of that device, I think that ioctl approach would
> be preferable in this case.
> Something like create /dev/cpuN and allow some ioctls on it:
> ioctl(cpu_fd, CPU_RDMSR, arg).
> What do you think?
>
While I think this (devcpu) is good for testing and development, I
prefer having a device driver to handle that specific MSR than a generic
/dev/cpuN where you can issue MSRs.
Both for security and reliability reasons.
Regards,
--
Rui Paulo
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