Re: [PATCH 0/9] ppc/pnv: HOMER and OCC fixes and improvements

[Nicholas Piggin]

On Tue Jan 7, 2025 at 8:00 AM AEST, Cédric Le Goater wrote:
> Hello,
>
> On 12/10/24 04:04, Nicholas Piggin wrote:
> > This series makes a bunch of fixes and improvements to the HOMER and
> > OCC unit models for powernv. It gets OPAL OCC code happier again,
>
> Nice. I had similar changes exposing pstates and sensors for QEMU.
> I am glad this is now possible.
>
> > but requires this series of skiboot fixes (which I will hope to get
> > upstream and then into QEMU in the same release as this series is
> > merged.
> > 
> > https://lists.ozlabs.org/pipermail/skiboot/2024-November/019013.html
> > 
> > Big changes is moving HOMER from mmio register implementation to a
> > RAM memory region which better maches hardware and is much easier to
> > work with; and the addition of some dynamic OCC behaviour to the
> > device model.
> > 
> > I wouldn't expect any review of OCC details. It's neglected and this
> > series gets it in better shape than before. But anything on the
> > basic structure and QEMU details is welcome. I will add some test
> > cases to help ensure it doesn't regress in future, I will have to
> > juggle the skiboot fixes as well though, so will do that later.
>
> Have you considered modeling the OCC in QEMU ? I am asking because
> I have a series removing all 405 support in QEMU 10.0.

Yes we are looking at modelling some of the microcontrollers by
emulating them not just simple state machines. I think starting
with SBE, but OCC is on the wishlist.

Perhaps hold off the removal for now?

Thanks,
Nick