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@xxxxxxxxx>
Thank you. I merged this and added changelog entry.
/Jarkko
