Re: [PATCH v14 04/19] x86/cpufeatures: Add SGX feature bits

[Jarkko Sakkinen]

On Wed, Sep 26, 2018 at 01:36:17PM +0200, Borislav Petkov wrote:
> On Wed, Sep 26, 2018 at 02:11:39PM +0300, Jarkko Sakkinen wrote:
> > Thank you. I guess I understand what you want me to do i.e.
> > 
> > +       { X86_FEATURE_SGX1,             CPUID_EAX,  0, 0x00000012, 0 },
> > +       { X86_FEATURE_SGX2,             CPUID_EAX,  1, 0x00000012, 0 },
> > +       { X86_FEATURE_ENCLV,            CPUID_EAX,  5, 0x00000012, 0 },
> > +       { X86_FEATURE_ENCLS_C,          CPUID_EAX,  6, 0x00000012, 0 },
> 
> Yap.
> 
> > What puzzles me is that I cannot find any call site for
> > get_scattered_cpuid_leaf():
> > 
> > $ git grep get_scattered
> > arch/x86/kernel/cpu/cpu.h:extern u32 get_scattered_cpuid_leaf(unsigned int level,
> > arch/x86/kernel/cpu/scattered.c:u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf,
> > arch/x86/kernel/cpu/scattered.c:EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf);
> 
> That used to be used in kvm last, see b7b27aa011a1df42728d1768fc181d9ce69e6911,
> which removed it.
> 
> And it got added by
> 
>   47bdf3378d62 ("x86/cpuid: Provide get_scattered_cpuid_leaf()")
> 
> Lemme add those people to CC.
> 
> If no one wants it, feel free to decomission it.

Still kind of leaves me puzzled about the situation :-) Why this wasn't
used for example to replace detect_vmx_virtcap()?

/Jarkko