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Date: Sat, 17 May 2008 20:10:41 +0300
From: Andriy Gapon <avg@icyb.net.ua>
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To: Rui Paulo <rpaulo@FreeBSD.org>
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Cc: freebsd-hackers@FreeBSD.org
Subject: Re: rdmsr from userspace
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on 17/05/2008 18:37 Rui Paulo said the following:
> 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.

What about /dev/pci, /dev/io? Aren't they a precedent?


-- 
Andriy Gapon