x86/cpufeature: Detect CPUID faulting support

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 <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Cc: Grzegorz Andrejczuk <[email protected]>
Cc: [email protected]
Cc: Radim Krčmář <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: [email protected]
Cc: Nadav Amit <[email protected]>
Cc: Robert O'Callahan <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: [email protected]
Cc: Jeff Dike <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: [email protected]
Cc: David Matlack <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: [email protected]
Cc: Paolo Bonzini <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

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