Re: [PATCH v16 05/13] x86/sev: Add Secure TSC support for SNP guests

Borislav Petkov
2025-01-08T08:44:14Z

On Wed, Jan 08, 2025 at 02:07:07PM +0530, Nikunj A. Dadhania wrote:
> >> void __init snp_secure_tsc_prepare(void)
> >> {
> >> - if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
> >> + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP) ||
> >> + !cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
> >
> > So how is moving the CC_ATTR_GUEST_SEV_SNP check here make any sense?
>
> In the comment that you gave here[1], I understood that this check has
> to be pushed to snp_secure_tsc_prepare().

The check should be pushed there but you should not check
CC_ATTR_GUEST_SEV_SNP *and* CC_ATTR_GUEST_SNP_SECURE_TSC if all you wanna do
is check if you're running a STSC guest. That was the whole point.

--
Regards/Gruss,
Boris.