Re: [PATCH v2 20/20] tests: add some virtio-gpu & vhost-user-gpu acceptance test

["Alex Bennée" <alex.bennee@linaro.org>]

Marc-André Lureau <marcandre.lureau@redhat.com> writes:

> Hi
>
> On Tue, Feb 16, 2021 at 9:43 PM Cleber Rosa <crosa@redhat.com> wrote:
>
>> On Tue, Feb 16, 2021 at 04:34:06PM +0000, Alex Bennée wrote:
>> >
>> > marcandre.lureau@redhat.com writes:
>> >
>> > > From: Marc-André Lureau <marcandre.lureau@redhat.com>
>> > >
>> > > This will check virtio/vhost-user-vga & virgl are correctly initialized
>> > > by the Linux kernel on an egl-headless display.
>> > >
>> > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> > > ---
>> > >  tests/acceptance/virtio-gpu.py | 161 +++++++++++++++++++++++++++++++++
>> > >  1 file changed, 161 insertions(+)
>> > >  create mode 100644 tests/acceptance/virtio-gpu.py
>> >
>> > This failed when I got to master:
>> >
>> >   2021-02-16 14:33:46,266 qmp              L0255 DEBUG| >>> {'execute':
>> 'qmp_capabilities'}
>> >   2021-02-16 14:33:46,441 machine          L0385 DEBUG| Error launching
>> VM
>> >   2021-02-16 14:33:46,441 machine          L0387 DEBUG| Command:
>> './qemu-system-x86_64 -display none -vga none -chardev
>> socket,id=mon,path=/var/tmp/avo_qemu_sock_xy9ndjnm/qemu
>> >   -29492-monitor.sock -mon chardev=mon,mode=control -chardev
>> socket,id=console,path=/var/tmp/avo_qemu_sock_xy9ndjnm/qemu-29492-console.sock,server=on,wait=off
>> -serial chardev:
>> >   console -cpu host -m 2G -machine pc,accel=kvm -device
>> virtio-vga,virgl=on -display egl-headless -kernel
>> /home/alex.bennee/avocado/data/cache/by_location/892ae21f3ae7d04994d8
>> >   1e1c0bf204ecebe555bb/vmlinuz -initrd
>> /home/alex.bennee/avocado/data/cache/by_location/892ae21f3ae7d04994d81e1c0bf204ecebe555bb/initrd.img
>> -append printk.time=0 console=ttyS0
>> >    rdinit=/bin/bash'
>> >   2021-02-16 14:33:46,441 machine          L0389 DEBUG| Output:
>> "qemu-system-x86_64: -device virtio-vga,virgl=on: Property
>> 'virtio-vga.virgl' not found\n"
>> >   2021-02-16 14:33:46,441 stacktrace       L0039 ERROR|
>> >
>> > I'm going to assume this is because the beefy server I was building on
>> > didn't have the VirGL headers to enable this feature. In lieu of feature
>> > probing you might have to do what I did for the plugins test:
>> >
>> >         try:
>> >             vm.launch()
>> >         except:
>> >             # TODO: probably fails because plugins not enabled but we
>> >             # can't currently probe for the feature.
>> >             self.cancel("TCG Plugins not enabled?")
>> >
>> >
>>
>> While this pattern is indeed an improvement over test errors, checking
>> for "build time features" is far from a new testing requirement, and
>> its still not properly solved.  A long time ago I proposed a way to
>> look at the Makefile variables during test time, but it had a number
>> of shortcomings.  I guess it's now time to revisit this issue.
>>
>> First, I'm a strong believer in limiting the *probing* that the test itself
>> does with regards to build time features.  The probing and authoritative
>> information should already be with the build system.  I'm pretty sure that
>> meson makes it easy to grab that kind of information.
>>
>> Once it's understood and agreed that the build system will provide
>> that information, the question becomes whether tests will get that
>> information from the build system (and thus require a build tree) or
>> if that information will be persisted in the QEMU binary and be
>> available for introspection.
>>
>> Thoughts? Does this sound like something other people would be
>> interested in?
>>
>
> It would be more reliable and flexible to do runtime introspection. It
> would allow installed tests, and some runtime checks for example.
>
> Given the variability of builds, is there something that does introspection
> in avocado-vt already?  I think we could rely on qmp introspection,
> qom-list-types etc.
>
> In the meantime Alex, could you send a patch to ignore the test the way you
> propose?

Sure.


-- 
Alex Bennée