Re: [PATCH 05/16] x86/sev: Move check for SNP Secure TSC support to tsc_early_init()

[Nikunj A Dadhania <nikunj@xxxxxxx>]

Sean Christopherson <seanjc@xxxxxxxxxx> writes:

> Move the check on having a Secure TSC to the common tsc_early_init() so
> that it's obvious that having a Secure TSC is conditional, and to prepare
> for adding TDX to the mix (blindly initializing *both* SNP and TDX TSC
> logic looks especially weird).

Agree.

>
> No functional change intended.
>
> Cc: Nikunj A Dadhania <nikunj@xxxxxxx>
> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Reviewed-by: Nikunj A Dadhania <nikunj@xxxxxxx>

> ---
>  arch/x86/coco/sev/core.c | 3 ---
>  arch/x86/kernel/tsc.c    | 3 ++-
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
> index e6ce4ca72465..dab386f782ce 100644
> --- a/arch/x86/coco/sev/core.c
> +++ b/arch/x86/coco/sev/core.c
> @@ -3284,9 +3284,6 @@ void __init snp_secure_tsc_init(void)
>  {
>       unsigned long long tsc_freq_mhz;
>  
> -     if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
> -             return;
> -
>       setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
>       setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
>  
> diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
> index 5a16271b7a5c..09ca0cbd4f31 100644
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -1514,7 +1514,8 @@ void __init tsc_early_init(void)
>       if (is_early_uv_system())
>               return;
>  
> -     snp_secure_tsc_init();
> +     if (cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
> +             snp_secure_tsc_init();
>  
>       if (!determine_cpu_tsc_frequencies(true))
>               return;
> -- 
> 2.48.1.362.g079036d154-goog