Currently the QEMU driver secretly sets the QEMU_AUDIO_DRV env variable
- VNC - set to "none", unless passthrough of host env variable is set
- SPICE - always set to "spice"
- SDL - always passthrough host env
- No graphics - set to "none", unless passthrough of host env variable is set
The setting of the QEMU_AUDIO_DRV env variable is done in the code which
configures graphics.
If no <audio> element is present, we now auto-populate <audio> elements
to reflect this historical default config. This avoids need to set audio
env when processing graphics.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
