[PATCH v2 0/4] KVM: arm64: Hide unsupported MPAM from the guest

[Jing Zhang]

Hi James,

Will you have a new version for this patch series?

Jing

On Tue, Jan 23, 2024 at 11:06 AM Oliver Upton <oliver.upton at linux.dev> wrote:
>
> On Fri, Jan 19, 2024 at 05:15:59PM +0000, James Morse wrote:
>
> [...]
>
> > > We've already done something similar to hide our mistakes with IMP DEF
> > > PMU versions in commit f90f9360c3d7 ("KVM: arm64: Rewrite IMPDEF PMU
> > > version as NI"), and I think MPAM may be a good candidate for something
> > > similar.
> >
> > As there is precedent, I feel less dirty doing that!
> >
> > This also solves the problem of the VMM re-writing the broken value after the vCPU has
> > started running, and getting a surprise error. A weird side effect of doing this would be
> > you can write MPAM=1 on A53 and KVM will ignore it, I don't want user-space to start
> > relying on that! I'll add a final-cap check so this can only be ignored on hardware that
> > actually has MPAM, and could have been exposed to the bug.
>
> Ah, good idea. I probably should've done something similar in the PMU
> case.
>
> --
> Thanks,
> Oliver
>