Re: [PATCH v12 5/7] x86/cpufeature: Detect CPUID faulting support

[Borislav Petkov]

On Wed, Nov 16, 2016 at 06:06:08PM -0800, Kyle Huey wrote:
> Intel supports faulting on the CPUID instruction beginning with Ivy Bridge.
> When enabled, the processor will fault on attempts to execute the CPUID
> instruction with CPL>0. This will allow a ptracer to emulate the CPUID
> instruction.
> 
> Bit 31 of MSR_PLATFORM_INFO advertises support for this feature. It is
> documented in detail in Section 2.3.2 of
> https://bugzilla.kernel.org/attachment.cgi?id=243991
> 
> Detect support for this feature and expose it as X86_FEATURE_CPUID_FAULT.
> 
> Signed-off-by: Kyle Huey <khuey@xxxxxxxxxxxx>
> ---
>  arch/x86/include/asm/cpufeatures.h |  1 +
>  arch/x86/include/asm/msr-index.h   |  2 ++
>  arch/x86/kernel/cpu/intel.c        | 12 ++++++++++++
>  3 files changed, 15 insertions(+)

Reviewed-by: Borislav Petkov <bp@xxxxxxx>

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix ImendÃrffer, Jane Smithard, Graham Norton, HRB 21284 (AG NÃrnberg)
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