Re: [Qemu-devel] [PATCH] hw/s390x: Fix the function arguments in the pci stub file

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 11 Feb 2019 11:54:45 +0100
Thomas Huth <thuth@redhat.com> wrote:

> On 2019-02-11 11:48, Cornelia Huck wrote:
> > On Fri, 1 Feb 2019 09:23:56 +0100
> > Cornelia Huck <cohuck@redhat.com> wrote:
> >   
> >> On Fri, 1 Feb 2019 07:46:40 +0100
> >> Thomas Huth <thuth@redhat.com> wrote:  
> >   
> >>> So I see two options now:
> >>>
> >>> 1) Finally really make the device optional, at least for new machine
> >>> types, so we can really disable CONFIG_PCI and get a working executable.
> >>>
> >>> 2) Scratch the idea completely to make this optional, always link the
> >>> s390-pci-bus.o and s390-pci-inst.o files unconditionally, and remove the
> >>> s390-pci-stub.c file.
> >>>
> >>> I assume options 2 is preferred, since we likely rather want to move
> >>> into the PCI direction in the long run, instead of ignoring it...    
> >>
> >> I think both options are viable, but option 1 is of course more work.
> >> The win there is that we could disable an entire subsystem.
> >>
> >> I guess that the basic questions are: How important is it that
> >> subsystems can be compiled out, and do we see a use case for a pci-less
> >> s390 machine in the future? We really don't want to spend much time on
> >> something of dubious use...  
> > 
> > Any thoughts on this?
> > 
> > I'm currently tending towards option 2 (and can cook up a patch for
> > that). Unless someone is already working on option 1 :)  
> 
> Since nobody currently has a need to completely disable PCI, I think we
> should go with option 2.

Hm... I'm wondering if we also should move S390_FEAT_ZPCI from the max
cpu model to the qemu cpu model (is there any reason not to turn it on
by default in tcg?)