Re: [PATCH v2 2/2] runqemu: Add a background command option

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2017-03-24 at 13:38 -0700, Alistair Francis wrote:
> This allows callers to specify commands that should be run in the
> background
> while running QEMU. This can be specified by assigning the commands
> to the
> 'QB_BACKGROUND_COMMAND' varialbe in the machine conf.
> 
> This is useful for starting automated debugging instances, automated
> testing instances (using QMP) or other servers/clients that QEMU can
> connect to.
> 
> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
> ---
>  scripts/runqemu | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/scripts/runqemu b/scripts/runqemu
> index f76d976..b5cc56a 100755
> --- a/scripts/runqemu
> +++ b/scripts/runqemu
> @@ -1118,6 +1118,13 @@ class BaseConfig(object):
>                  kernel_opts += " -dtb %s" % self.dtb
>          else:
>              kernel_opts = ""
> +        background_cmd = self.get('QB_BACKGROUND_COMMAND')
> +
> +        if background_cmd:
> +            logger.info('Running in the background %s' %
> background_cmd)
> +            if subprocess.call(background_cmd + ' &', shell=True) !=
> 0:
> +                raise Exception('Failed to run %s' % cmd)
> +

I have to admit I'm rather unsure about this. What cleans up this
process when runqemu finishes?

We tend to run into a lot of issues around cleanup and a subprocess
using "&" doesn't sound too attractive given the general issues we run
into.

Cheers,

Richard