Re: [PATCH v6 03/11] x86: define IA32_FEATURE_CONTROL.SGX_ENABLE

[Jarkko Sakkinen]

On Tue, Nov 28, 2017 at 09:13:18AM -0800, Sean Christopherson wrote:
> On Sat, 2017-11-25 at 21:29 +0200, Jarkko Sakkinen wrote:
> > From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> > 
> > When IA32_FEATURE_CONTROL.SGX_ENABLE and IA32_FEATURE_CONTROL.LOCK are
> > set by the pre-boot firmware, SGX is usable by the OS.
> 
> This implies that only pre-boot firmware can write feature control, which is not
> true.  What about:
> 
>     SGX instructions (ENCLS and ENCLU) are usable if and only if SGX_ENABLE is
>     set in the IA32_FEATURE_CONTROL MSR and said MSR is locked.

You are correct, thanks. I'll fix this for v7.

/Jarkko