Re: [PATCHv6 01/30] x86/tdx: Detect running as a TDX guest in early boot

[Thomas Gleixner]

On Wed, Mar 16 2022 at 05:08, Kirill A. Shutemov wrote:
> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
>
> In preparation of extending cc_platform_has() API to support TDX guest,
> use CPUID instruction to detect support for TDX guests in the early
> boot code (via tdx_early_init()). Since copy_bootdata() is the first
> user of cc_platform_has() API, detect the TDX guest status before it.
>
> Define a synthetic feature flag (X86_FEATURE_TDX_GUEST) and set this
> bit in a valid TDX guest platform.
>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Reviewed-by: Borislav Petkov <bp@xxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>