Re: [PATCH-for-9.0 v2 01/19] tests/avocado: Add 'guest:xen' tag to tests running Xen guest

[Philippe Mathieu-Daudé]

On 14/11/23 16:08, David Woodhouse wrote:
> On 14 November 2023 10:00:09 GMT-05:00, "Philippe Mathieu-Daudé" 
> <philmd@linaro.org> wrote:
> > On 14/11/23 15:50, David Woodhouse wrote:
> > > On 14 November 2023 09:37:57 GMT-05:00, "Philippe Mathieu-Daudé" 
> > > <philmd@linaro.org> wrote:
> > > > Add a tag to run all Xen-specific tests using:
> > > >
> > > >    $ make check-avocado AVOCADO_TAGS='guest:xen'
> > > >
> > > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > > > ---
> > > > tests/avocado/boot_xen.py      | 3 +++
> > > > tests/avocado/kvm_xen_guest.py | 1 +
> > > > 2 files changed, 4 insertions(+)
> > >
> > > Those two are very different. One runs on Xen, the other on KVM. Do we want to 
> > > use the same tag for both?
> >
> > My understanding is,
> > - boot_xen.py runs Xen on TCG
> > - kvm_xen_guest.py runs Xen on KVM
> > so both runs Xen guests.
>
> Does boot_xen.py actually boot *Xen*? And presumably at least one Xen guest 
> *within* Xen?

I'll let Alex confirm, but yes, I expect Xen guest within Xen guest 
within TCG. So the tags "accel:tcg" (already present) and "guest:xen".

> kvm_xen_guest.py boots a "Xen guest" under KVM directly without any real Xen 
> being present. It's *emulating* Xen.

Yes, so the tag "guest:xen" is correct.

> They do both run Xen guests (or at least guests which use Xen hypercalls and 
> *think* they're running under Xen). But is that the important classification 
> for lumping them together?

The idea of AVOCADO_TAGS is to restrict testing to what you want to 
cover. So here this allow running 'anything that can run Xen guest'
in a single command, for example it is handy on my macOS aarch64 host.