On Wed, Dec 20, 2023 at 4:16 PM Nikunj A Dadhania <nikunj@xxxxxxx> wrote: > + /* Setting Secure TSC parameters */ > + if (cpu_feature_enabled(X86_FEATURE_SNP_SECURE_TSC)) { > + vmsa->tsc_scale = snp_tsc_scale; > + vmsa->tsc_offset = snp_tsc_offset; > + } This needs to use guest_cpu_has, otherwise updating the hypervisor or processor will change the initial VMSA and any measurement derived from there. In fact, the same issue exists for DEBUG_SWAP and I will shortly post a series to allow enabling/disabling DEBUG_SWAP per-VM, so that updating the kernel does not break existing measurements. Paolo