Re: [PATCH v13 06/14] x86/mm: use broadcast TLB flushing for page reclaim TLB flushing

From: Tom Lendacky
Date: Wed Feb 26 2025 - 12:00:17 EST


On 2/25/25 15:03, Borislav Petkov wrote:
> On Tue, Feb 25, 2025 at 09:38:03PM +0100, Borislav Petkov wrote:
>> On Tue, Feb 25, 2025 at 02:17:20PM -0500, Rik van Riel wrote:
>>> Who do we need to ask to confirm that reading?
>>
>> Lemme figure it out.
>
> Confirmed - that really is the case.

Hmmm... since this is for host/hypervisor TLB handling, this makes me
think that we should always be setting the ASID valid bit with 0 for the
ASID value in EDX[15:0] on all INVLPGB instructions in this series.
Otherwise we will also be flushing any guest ASID TLB entries that match
the conditions, when that isn't intended.

Thanks,
Tom

>
> Thx.
>