Re: [patch V3 27/40] x86/cpu: Provide a sane leaf 0xb/0x1f parser

From: Thomas Gleixner
Date: Sun Aug 13 2023 - 11:04:44 EST


On Sat, Aug 12 2023 at 22:04, Thomas Gleixner wrote:
> On Sat, Aug 12 2023 at 08:21, Rui Zhang wrote:
>> With this, we can guarantee that all the available topology information
>> are always valid, even when running on future platforms.
>
> I know that it can be made work, but is it worth the extra effort? I
> don't think so.

So I thought more about it. For intermediate levels, i.e. something
which is squeezed between two existing levels, this works by some
definition of works.

I.e. the example where we have UBER_TILE between TILE and DIE, then we'd
set and propagate the UBER_TILE entry into the DIE slot and then
overwrite it again, if there is a DIE entry too.

Where it becomes interesting is when the unknown level is past DIEGRP,
e.g. DIEGRP_CONGLOMORATE then we'd need to overwrite the DIEGRP level,
right?

It can be done, but I don't know whether it buys us much for the purely
theoretical case of new levels added.

Thanks,

tglx