Re: [PATCH v15 15/37] KVM: arm64: CCA: Handle RMI_EXIT_RIPAS_CHANGE

[Fuad Tabba]

Hi Suzuki,

+ Quentin (who's on leave, but for when he gets back)

On Mon, 3 Aug 2026 at 16:30, Suzuki K Poulose <suzuki.poulose@xxxxxxx> wrote:
...
> > I.e don't hack into the API. Use the information you already have to
> > decide whether you need to use the existing API at all.
> >
> > If that cannot be done for whatever reason, then you need to indirect
> > the call with a set of operations that leave the existing code
> > untouched.
>
> Please let us know if you think we need to explore this ^ ?

FWIW, pKVM already has this kind of indirection: in protected mode,
the kvm_pgtable_stage2_* calls in mmu.c dispatch to the
pkvm_pgtable_stage2_* wrappers through KVM_PGT_FN(), and the callers
don't branch. It is global today because pKVM owns the whole host, but
a per-VM version would let the CCA backend handle the filter and the
IPA aliasing internally, keeping __unmap_stage2_range()'s signature
intact. That should work for pKVM as well.

Cheers,
/fuad