Re: [PATCHv6 00/16] x86: Enable Linear Address Space Separation support

Dave Hansen
2025-06-20T22:46:16Z

On 6/20/25 15:04, Andrew Cooper wrote:
>> Most of the cover letter here reads like an Intel whitepaper. That's not
>> the worst thing in the world, but I think it glosses over one very
>> important point:
>>
>> Had it been available, LASS alone would have mitigated Meltdown.
>>
>> Could we say this up front in a prominent place, please?
>
> I'm going to nitpick. :)
>
> Yes, LASS would have made Meltdown a far less major problem than it was,
> but I don't think that phrasing is fair.  As I recall, LASS was
> literally invented as a "what would have been useful?" exercise in the
> wake of Meltdown.

While being concise, I was also trying to convey that LASS is pretty
powerful, rather than it being some uniquely genius move by the CPU
designers. It was absolutely conceived of in hindsight.

Do you feel like the changelog is sufficient as-is? Or do you think we
can beef the changelog up a bit? I just want to make sure folks reading
it have a clear understanding that it's not fixing purely theoretical
issues.