Re: [PATCH 2/2] tests/qtest: Special case sbsa-ref and xlnx-versal-virt if !CONFIG_ARM_GIC_TCG

[Peter Maydell]

On Mon, 31 Jan 2022 at 16:14, Andrew Jones <drjones@redhat.com> wrote:
>
> On Mon, Jan 31, 2022 at 04:05:06PM +0000, Peter Maydell wrote:
> > On Mon, 31 Jan 2022 at 15:59, Andrew Jones <drjones@redhat.com> wrote:
> > > Hmm, if these machine types completely depend on userspace gicv3
> > > emulation, i.e. no way to use in-kernel gic or another tcg gic
> > > model, then I guess they shouldn't be built at all when ARM_GIC_TCG
> > > isn't configured. I.e.
> > >
> > > diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> > > index 2e0049196d6c..d7cc028b049d 100644
> > > --- a/hw/arm/Kconfig
> > > +++ b/hw/arm/Kconfig
> > > @@ -209,6 +209,7 @@ config REALVIEW
> > >
> > >  config SBSA_REF
> > >      bool
> > > +    depends on ARM_GIC_TCG
> > >      imply PCI_DEVICES
> > >      select AHCI
> > >      select ARM_SMMUV3
> > > @@ -378,6 +379,7 @@ config XLNX_ZYNQMP_ARM
> > >
> > >  config XLNX_VERSAL
> > >      bool
> > > +    depends on ARM_GIC_TCG
> > >      select ARM_GIC
> > >      select PL011
> > >      select CADENCE
> >
> > I kind of agree, but isn't this kind of mixing two things?
>
> How about two dependencies?
>
> >
> > (1) Both these machines require a GICv3 and a GICv2 won't do,
> > so they should do something that says "if you want this
> > machine type, you need a GICv3 device"
>
> depends on ARM_GIC_TCG   (IMO, could use a rename to be gicv3 specific)

ARM_GIC_TCG has a "depends on ARM_GIC && TCG", though.
"I need a GICv3" ought in principle to be satisfiable by
the KVM GICv3.

Part of the problem here is that we've let ARM_GIC mean both
GICv2 and GICv3.

> > (2) Both these machines don't work with KVM or hvf, so if we're
> > not building TCG then there's no point configuring in these
> > machine models (a property they share with every other arm
> > machine type except "virt", currently)
>
> depends on TCG

I would prefer a way of phrasing this that only required
us to say it in the one machine that can handle not-TCG
(virt) rather than in the large number of machines that cannot...

-- PMM