On 11.10.2022 18:02, Roger Pau Monne wrote:
> --- a/xen/arch/x86/cpu/amd.c
> +++ b/xen/arch/x86/cpu/amd.c
> @@ -814,7 +814,9 @@ void amd_set_ssbd(bool enable)
> wrmsr(MSR_VIRT_SPEC_CTRL, enable ? SPEC_CTRL_SSBD : 0, 0);
> else if ( amd_legacy_ssbd )
> core_set_legacy_ssbd(enable);
> - else
> + else if ( cpu_has_ssb_no ) {
Nit: While already an issue in patch 1, it is actually the combination
of inner blanks and brace placement which made me spot the style issue
here.
> + /* Nothing to do. */
How is the late placement here in line with ...
> --- a/xen/arch/x86/cpuid.c
> +++ b/xen/arch/x86/cpuid.c
> @@ -558,11 +558,16 @@ static void __init calculate_hvm_max_policy(void)
> __clear_bit(X86_FEATURE_IBRSB, hvm_featureset);
> __clear_bit(X86_FEATURE_IBRS, hvm_featureset);
> }
> - else if ( boot_cpu_has(X86_FEATURE_AMD_SSBD) )
> + else if ( boot_cpu_has(X86_FEATURE_AMD_SSBD) ||
> + boot_cpu_has(X86_FEATURE_SSB_NO) )
> /*
> * If SPEC_CTRL.SSBD is available VIRT_SPEC_CTRL.SSBD can be exposed
> * and implemented using the former. Expose in the max policy only as
> * the preference is for guests to use SPEC_CTRL.SSBD if available.
> + *
> + * Allow VIRT_SSBD in the max policy if SSB_NO is exposed for
> migration
> + * compatibility reasons. If SSB_NO is present setting
> + * VIRT_SPEC_CTRL.SSBD is a no-op.
> */
> __set_bit(X86_FEATURE_VIRT_SSBD, hvm_featureset);
... this comment addition talking about "no-op"?
Jan
