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

[Kuppuswamy, Sathyanarayanan]

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.

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer