Re: [PATCH 02/25] x86/cpufeatures: Add SGX1 and SGX2 sub-features

[Borislav Petkov]

On Mon, Mar 01, 2021 at 10:44:29PM +1300, Kai Huang wrote:
> From: Sean Christopherson <seanjc@xxxxxxxxxx>
> 
> Add SGX1 and SGX2 feature flags, via CPUID.0x12.0x0.EAX, as scattered
> features, since adding a new leaf for only two bits would be wasteful.
> As part of virtualizing SGX, KVM will expose the SGX CPUID leafs to its
> guest, and to do so correctly needs to query hardware and kernel support
> for SGX1 and SGX2.
> 
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx>
> Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
> ---
>  arch/x86/include/asm/cpufeatures.h | 2 ++
>  arch/x86/kernel/cpu/cpuid-deps.c   | 2 ++
>  arch/x86/kernel/cpu/scattered.c    | 2 ++
>  3 files changed, 6 insertions(+)
> 
> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> index cc96e26d69f7..9502c445a3e9 100644
> --- a/arch/x86/include/asm/cpufeatures.h
> +++ b/arch/x86/include/asm/cpufeatures.h
> @@ -290,6 +290,8 @@
>  #define X86_FEATURE_FENCE_SWAPGS_KERNEL	(11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */
>  #define X86_FEATURE_SPLIT_LOCK_DETECT	(11*32+ 6) /* #AC for split lock */
>  #define X86_FEATURE_PER_THREAD_MBA	(11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
> +#define X86_FEATURE_SGX1		(11*32+ 8) /* "" Basic SGX */
> +#define X86_FEATURE_SGX2        	(11*32+ 9) /* SGX Enclave Dynamic Memory Management (EDMM) */

"sgx1" is not gonna show in /proc/cpuinfo but "sgx2" will. Because...?

Also, you send a patchset once a week - not after two days. Please limit
your spamming.

-- 
Regards/Gruss,
    Boris.

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