Re: [patch V4 28/41] x86/cpu: Provide a sane leaf 0xb/0x1f parser

Thomas Gleixner
2023-08-17T09:11:53Z

On Wed, Aug 16 2023 at 12:09, Rui Zhang wrote:
>> +       } else if (tscan->c->topo.initial_apicid != sl.x2apic_id) {
>> +               pr_warn_once(FW_BUG "CPUID leaf 0x%x subleaf %d APIC
>> ID mismatch %x != %x\n",
>> +                            leaf, subleaf, tscan->c-
>> >topo.initial_apicid, sl.x2apic_id);
>> +       }
>> +
>
> Maybe worth a warning somewhere if sl.x2apic_shift !=
> x86_topo_system.dom_shifts[dom], because invariant x2apic_shift (for
> the same level) among different CPUs is critical for this patch series.
> And I do see variant x2apic_shift on an Intel AlderLake NUC, which has
> been identified to be a microcode bug later.

Yes, we can do that.