Re: [PATCH v4 03/11] ppc/pnv: New powernv10-rainier machine type

[Cédric Le Goater]

On 11/21/23 17:36, Miles Glenn wrote:
> On Tue, 2023-11-21 at 08:29 +0100, Cédric Le Goater wrote:
> > On 11/21/23 02:33, Nicholas Piggin wrote:
> > > On Tue Nov 21, 2023 at 9:51 AM AEST, Glenn Miles wrote:
> > > > Create a new powernv machine type, powernv10-rainier, that
> > > > will contain rainier-specific devices.
> > >
> > > Is the plan to have a base powernv10 common to all and then
> > > powernv10-rainier looks like a Rainier? Or would powernv10
> > > just be a rainier?
> > >
> > > It's fine to structure code this way, I'm just wondering about
> > > the machine types available to user. Is a base powernv10 machine
> > > useful to run?
> >
> > There are multiple P10 boards defined in Linux :
> >
> >     aspeed-bmc-ibm-bonnell.dts
> >     aspeed-bmc-ibm-everest.dts
> >     aspeed-bmc-ibm-rainier-1s4u.dts
> >     aspeed-bmc-ibm-rainier-4u.dts
> >     aspeed-bmc-ibm-rainier.dts
> >
> > and we could model the machines above with a fixed number of sockets.
> > The "powernv10" would be the generic system that can be customized
> > at will on the command line, even I2C devices. There is also the
> > P10 Denali which is FSP based. This QEMU machine would certainly be
> > very different. I thought of doing the same for P9 with a -zaius
> > and include NPU2 models for it. I lacked time and the interest was
> > small at the time of OpenPOWER.
> >
> > Anyhow, adding a new machine makes sense and it prepares ground for
> > possible new ones. I am OK with or without. As primary users, you are
> > the ones that can tell if there will be a second machine.
> >    
> > Thanks,
> >
> > C.
>
> I am not sure what the powernv10 machine would be used for.  The
> only reason I kept it was because I didn't want to break anyone out
> there that might be using it.
(previous email sent to fast)

You would need to go through the deprecation process [1] if you want
to remove the machine. I suggest keeping it for now since it is two
lines of type definition.

> My preference would have been to just make powernv10-rainier an
> alias of the powernv10 machine, but only one alias name per machine
> is supported and there is already a plan to make "powernv" an
> alias for the powernv10 machine.

yes. It might be time now for PowerNV and pSeries to update the
default processor. Let's address that in the QEMU 9.0 cycle.

Thanks,

C.

[1] https://qemu.readthedocs.io/en/v8.1.0/about/deprecated.html