Re: [PATCH 1/8] build-system: clean up TCG/TCI configury

["Daniel P. Berrangé" <berrange@redhat.com>]

On Wed, Jan 13, 2021 at 02:42:51PM +0100, Helge Deller wrote:
> On 1/13/21 2:09 PM, Philippe Mathieu-Daudé wrote:
> > Cc'ing TCI, SH4 and PA contacts FWIW.
> >
> > On 1/7/21 5:06 PM, Daniel P. Berrangé wrote:
> >> On Thu, Jan 07, 2021 at 04:50:36PM +0100, Paolo Bonzini wrote:
> >>> On 07/01/21 16:01, Peter Maydell wrote:
> >>>> On Thu, 7 Jan 2021 at 14:03, Paolo Bonzini <pbonzini@redhat.com> wrote:
> >>>>>
> >>>>> Make CONFIG_TCG_INTERPRETER a Meson option, and enable TCI (though with
> >>>>> a warning) if the host CPU is unsupported, making it more similar to
> >>>>> other --enable-* options.
> >>>>
> >>>> The current behaviour is kind of deliberate. Using the TCG
> >>>> interpreter is a terrible idea and think it's better if we
> >>>> don't let users end up using it without realising that they have.
> >>>> (Personally I would vote to deprecate-and-delete TCI, and also
> >>>> to just have configure error out on unknown host CPU architectures.)
> >>>
> >>> Fair enough, I can change this back of course.  The missing targets are
> >>> parisc, ia64 and sh4 I guess.
> >>
> >> ia64 is a dead host architecture and doesn't exist in any OS distro that
> >> we target anymore, so I don't think we need to consider it.
> 
> I have no opinion about ia64.
> 
> >> Likewise parisc/hppa doesn't seem exist in Debian since Squeeze, so I
> >> think we can rule that out too.
> 
> Can we please keep parisc/hppa.
> It's not an official platform any longer, but quite active in the
> "unstable" debian-ports repository:
> https://buildd.debian.org/status/architecture.php?a=hppa&suite=sid
> 
> >> Only sh4 still seems to be supported in Debian. I expect the primary
> >> need there is for sh4 guest support rather than sh4 host support.
> 
> Same as for hppa/parisc, sh4 is in debian-ports too.

So that at least shows that we need *guest target* support hppa/sha4.

The question still remains whether anyone is actually likely to be
running/using QEMU on a sh4/hppa *host*, to emulate a different
guest arch ? This is what that TCG interpreter provides for.
eg would anyone really want to emulate aarch64 guest when runing on
a hppa host ?

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|