Re: [PATCH] fuzz: specify audiodev for usb-audio

[Alexander Bulekov]

On 240527 1007, Alexander Bulekov wrote:
> On 240527 0734, Thomas Huth wrote:
> > On 27/05/2024 06.07, Alexander Bulekov wrote:
> > > Fixes test-failure on Fedora 40 CI.
> > > 
> > > Reported-by: Thomas Huth <thuth@redhat.com>
> > > Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> > > ---
> > >   tests/qtest/fuzz/generic_fuzz_configs.h | 3 ++-
> > >   1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/tests/qtest/fuzz/generic_fuzz_configs.h 
> > > b/tests/qtest/fuzz/generic_fuzz_configs.h
> > > index 4d7c8ca4ec..ef0ad95712 100644
> > > --- a/tests/qtest/fuzz/generic_fuzz_configs.h
> > > +++ b/tests/qtest/fuzz/generic_fuzz_configs.h
> > > @@ -150,7 +150,8 @@ const generic_fuzz_config predefined_configs[] = {
> > >           "-chardev null,id=cd0 -chardev null,id=cd1 "
> > >           "-device usb-braille,chardev=cd0 -device usb-ccid -device 
> > > usb-ccid "
> > >           "-device usb-kbd -device usb-mouse -device 
> > > usb-serial,chardev=cd1 "
> > > -        "-device usb-tablet -device usb-wacom-tablet -device usb-audio",
> > > +        "-device usb-tablet -device usb-wacom-tablet "
> > > +        "-device usb-audio,audiodev=snd0 -audiodev none,id=snd0",
> > >           .objects = "*usb* *uhci* *xhci*",
> > >       }
> > 
> > Reviewed-by: Thomas Huth <thuth@redhat.com>
> > 
> > The patch makes sense and I think we should include it, thanks! .. but I
> > still don't understand why the behavior of the fuzzing job was different
> > between Fedora 38 and 40, do you? Why does it complain about "no default
> > audio driver available" on F40 but works fine on F38, though both build jobs
> > include the Alsa, pulseaudio and OSS backends?
> > 
> 
> Yes that's strange, if the behavior is different.
> The full config here is:
> 
> .args = "-machine q35 -nodefaults "
> "-drive file=null-co://,if=none,format=raw,id=disk0 "
> "-device qemu-xhci,id=xhci -device usb-tablet,bus=xhci.0 "
> "-device usb-bot -device usb-storage,drive=disk0 "
> "-chardev null,id=cd0 -chardev null,id=cd1 "
> "-device usb-braille,chardev=cd0 -device usb-ccid -device usb-ccid "
> "-device usb-kbd -device usb-mouse -device usb-serial,chardev=cd1 "
> "-device usb-tablet -device usb-wacom-tablet "
> "-device usb-audio"
> 
> This contains "nodefaults", which should always be causing the error,
> since this change:
> c753bf479a ("audio: disable default backends if -audio/-audiodev is used")
> 
> This adds audio to qemu_disable_default_devices, which should be called
> by -nodefaults. I wonder if for some reason the order in which the
> audiodev is configured and the default audiodev is disabled is different
> between builds.
> 

It might be even simpler. The recent jobs on Fedora 38 don't seem to
ever even make it to the xhci test, because of a detected leak:

https://gitlab.com/qemu-project/qemu/-/jobs/6949417820#L4375