Re: [PATCH for_v25] x86/sgx: Move SGX sub-feature bits to their own word

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Fri, Dec 20, 2019 at 03:08:29PM -0800, Sean Christopherson wrote:
> As requested by Boris, move the CPUID 0x12 features to their own word in
> cpufeatures.
> 
> This can be squashed cleanly with commit c3eac55d3882 ("x86/cpufeatures:
> x86/msr: Add Intel SGX hardware bits"), replacing paragraph
> 
>   Remap CPUID.(EAX=12H, ECX=0) bits to the Linux fake CPUID 8 in order to
>   conserve some space. Keep the bit positions intact because KVM requires
>   this. Reserve bits 0-7 for SGX in order to maintain this invariant also
>   when new SGX specific feature bits get added.
> 
> with
> 
>   Add the SGX sub-features in a new word even though only two bits will be
>   used in the immediate future.  KVM support for SGX is expected in the
>   not-too-distant future, and having a dedicated feature word allows KVM
>   to include SGX sub-features in its reserve-cpuid lookup table, e.g. to
>   easily query guest CPUID capabilities.
> 
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>

Thank you. I merged this and added changelog entry.

/Jarkko