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

Rik van Riel
2025-02-26T17:03:09Z

On Wed, 2025-02-26 at 11:00 -0600, Tom Lendacky wrote:
> 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.

The ASID is always zero in this series.

We only ever use the PCID for address space identification.

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