On 08/03/19 07:10, Xiaoyao Li wrote: >> so that non-virtualizable features are hidden and >> >> if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) >> data |= CORE_CAP_SPLIT_LOCK_DETECT; >> >> so that userspace gets "for free" the FMS list that will be added >> later to the kernel. > I think it's redundant. Because there is no case that > rdmsrl_safe(MSR_IA32_CORE_CAPABILITY, &data) shows no split lock detection while > boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT). There will be when the kernel will add a list of FMS values that have split lock detection but lack the core capabilities MSR. Or at least that is what Fenghua said in the cover letter. Paolo
