Re: [RFC PATCH] tests/avocado: probe for multi-process support before running test

[Philippe Mathieu-Daudé]

On 21/3/23 12:17, Alex Bennée wrote:
> A recent attempt to let avocado run more tests on the CentOS stream
> build failed because there was no gating on the multiprocess feature.
> Like missing accelerators avocado should gracefully skip when the
> feature is not enabled.
>
> In this case we use the existence of the proxy device as a proxy for
> multi-process support.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Cc: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> Cc: Jagannathan Raman <jag.raman@oracle.com>
> Cc: John G Johnson <john.g.johnson@oracle.com>
> ---
>   tests/avocado/avocado_qemu/__init__.py | 10 ++++++++++
>   tests/avocado/multiprocess.py          |  1 +
>   2 files changed, 11 insertions(+)


> +        """
> +        Test for the presence of the x-pci-proxy-dev which is required
> +        to support multiprocess.
> +        """
> +        devhelp = run_cmd([self.qemu_bin,
> +                           '-M', 'none', '-device', 'help'])[0];
> +        if devhelp.find('x-pci-proxy-dev') < 0:
> +            self.cancel('no support for multiprocess device emulation')

FYI a more generic alternative to this method:
https://lore.kernel.org/qemu-devel/20200129212345.20547-14-philmd@redhat.com/

But yours just works :)