Re: [PATCH v8 03/11] x86/cpufeatures: Add TDX Guest CPU feature

[Josh Poimboeuf]

On Tue, Oct 05, 2021 at 09:33:35PM -0700, Kuppuswamy, Sathyanarayanan wrote:
> 
> 
> On 10/5/21 8:42 PM, Josh Poimboeuf wrote:
> > > is_tdx_guest was mainly introduced to support cc_platform_has()
> > > API in early boot calls (similar to sme_me_mask in AMD code).
> > > Regarding FEATURE flag it will be useful for userspace tools to
> > > check the TDX feature support.
> > FEATURE flags can also be checked in the kernel, with boot_cpu_has().
> > Or am I missing something?
> 
> Yes, previously we have been using x86_feature_enabled() check in
> cc_platform_has() call. Now with the introduction of is_tdx_guest
> global variable, we don't use it in kernel. But I still want to
> keep the feature flag for user space use case.

I'm not suggesting getting rid of the feature flag.  I'm suggesting
getting rid of the global variable.  Is there a reason you can't check
the feature flag instead of checking the global variable?

-- 
Josh