On 12/7/2023 12:15 AM, Dionna Amalie Glaze wrote: >>>> + if (sev_status & MSR_AMD64_SNP_SECURE_TSC) >>>> + return ES_VMM_ERROR; >>> >>> Is this not a cc_platform_has situation? I don't recall how the >>> conversation shook out for TDX's forcing X86_FEATURE_TSC_RELIABLE >>> versus having a cc_attr_secure_tsc >> >> For SNP, SecureTSC is an opt-in feature. AFAIU, for TDX the feature is >> turned on by default. So SNP guests need to check if the VMM has enabled >> the feature before moving forward with SecureTSC initializations. >> >> The idea was to have some generic name instead of AMD specific SecureTSC >> (cc_attr_secure_tsc), and I had sought comments from Kirill [1]. After >> that discussion I have added a synthetic flag for Secure TSC[2]. >> > > So with regards to [2], this sev_status flag check should be > cpu_has_feature(X86_FEATURE_SNP_SECURE_TSC)? I'm not sure if that's > available in early boot where this code is used, so if it isn't, > probably that's worth a comment. Right, I will update the comment. Regards Nikunj
