Re: [RFC PATCH 3/5] hw/ppc: Have pSeries depends on libfdt (via host Kconfig FDT symbol)

[Paolo Bonzini]

On 12/05/21 04:27, David Gibson wrote:
> On Tue, May 11, 2021 at 05:53:52PM +0200, Philippe Mathieu-Daudé wrote:
> > Since commit fea35ca4b8e ("ppc/spapr: Receive and store device
> > tree blob from SLOF") the pSeries machine depends on the libfdt
> > fdt_check_full() call, which is available in libfdt v1.4.7.
> >
> > Add the corresponding Kconfig dependency.
> >
> > Signed-off-by: Philippe Mathieu-Daudé<philmd@redhat.com>
> I don't love making this conditional.  Pseries is by far the best
> tested and most widely used ppc machine type, so it seems like it
> would break expectations to not compile this in rather than giving an
> error saying you need a newer libfdt.

It's not conditional; if libfdt is not found, scripts/minikconf.py will 
tell you about the contradiction between CONFIG_PSERIES=y and 
"CONFIG_PSERIES depends on FDT".

So we still have the same "fdt_required" logic that is already in 
meson.build, but expressed as Kconfig rules instead of a random line in 
default-configs/targets.

Paolo