Hi Neil, Kevin !
On 20 July 2017 at 02:57, Kevin Hilman <khilman at baylibre.com> wrote:
Hello,
There are many configurable options when starting QEMU that are controlled by environment variables, and I'm trying to figure out how to pursuade LAVA v2 to set them.
It's not something which should be done with the QEMU device type because that is installed on the worker - it is not a device that can be reconfigured to suit test writers and much of the functionality of QEMU must remain off-limits when QEMU is running on the worker.
As an example, configuring the host audio driver used by QEMU is set by running QEMU with: QEMU_AUDIO_DRV=<option> qemu-system-x86_64.
The worker is typically a server, it might not have any audio support. Even if it does, that functionality is off-limits to test writers. The available options to QEMU must be tightly constrained to protect other tasks on the worker.
A see. There is a valid point here in that there should not be control of the environment from the 'outside' though a job description.
Unfortunately, device-types/qemu.jinja2 doesn't provide anyway to override the qemu-system binary used (it's conditional based on arch),
This is deliberate, to protect the worker from aberrant processes and to give the admins sufficient control over how the worker behaves.
Now for the above case: QEMU_AUDIO_DRV=<option> qemu-system-*
I see this as a *very valid env var* for a server-side deployment - exactly as you said - a server does not have a sound card and QEMU_AUDIO_DRV=none is what we need to use there to prevent qemu from looking for a host sound card. We should even set this by default - we don't expect any sound to reach the worker - do we ;) ? I don't think so.
IMHO this should be an option set on the worker node in the lava- dispatcher.conf (e.g. LAVA_EXTRA_QEMU_ENV="QEMU_AUDIO_DRV=none"). Enable the admins to choose this.
No. This is not something that the worker can support. It needs to happen only on a test device. The worker is not itself a test device.
As I said, I think this belongs to the worker setup and we should enable the admins to make their choice.
Dipl.-Ing. Jan-Simon Möller
jansimon.moeller@gmx.de