Re: [PATCH 3/3] x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM CPUID bit

H. Peter Anvin
2009-08-30T20:49:28Z

On 08/30/2009 01:29 PM, Borislav Petkov wrote:
>
> Ok, what do we want actually? We have rdmsr_safe and rdmsrl_safe where
> the last one engineers the 2 u32s into a u64. My gut feeling would opt
> for the 2 32bit values instead of one 64bit since they're naturally
> returned into %eax:%edx. And in the most cases we need only one of the
> values. However, the MSRs themselves are 64bit... Hmmm...
>

The 2x32 bit interface is the legacy interface. It turned out to be a
bad idea, but it's hard to clean up all the users.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.