Re: [PATCH] target/ppc: Use SMT4 small core chip type in POWER9/10 PVRs

[Nicholas Piggin]

On Tue May 16, 2023 at 6:44 PM AEST, Cédric Le Goater wrote:
> On 5/15/23 18:01, Nicholas Piggin wrote:
> > QEMU's PVR value for POWER9 DD2.0 has chip type 1, which is the SMT4
> > "small core" type that OpenPOWER processors use. QEMU's PVR for all
> > other POWER9/10 have chip type 0, which "enterprise" systems use.
> > 
> > The difference does not really matter to QEMU (because it does not care
> > about SMT mode in the target), but for consistency all PVRs should use
> > the same chip type. We'll go with the SMT4 OpenPOWER type.
> > 
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> > This is a replacement for
> > 
> > https://lists.gnu.org/archive/html/qemu-ppc/2022-03/msg00227.html
> > 
> > But the chip type is changed to 1 instead of 0, because that's the
> > more familiar SM4 / small core CPU.
>
> Will small cores POWER10 CPU be available ?

I don't know the answer to that, but even big core POWER10s need
non-standard OPAL firmware to use bare metal...

Small core is nicer for Linux to use and matches POWER9 so I did
that. In practice I don't think it will actually matter anywhere
because we don't do SMT.

Thanks,
Nick