On Tue, Nov 21, 2017 at 12:44:44PM +0100, Peter Krempa wrote: > On Tue, Nov 21, 2017 at 11:24:06 +0000, Daniel Berrange wrote: > > On Tue, Nov 14, 2017 at 02:45:08PM +0100, Pavel Hrdina wrote: > > > If there is no sound device configured for the guest we can disable the > > > audio output because hot-plugging sound devices isn't supported. > > > > Are you sure about that. While libvirt may not have wired up ability to > > hotplug sound devices, I'm pretty sure that QEMU is able to hotplug > > them. > > At least the USB sound card should allow hotplug in qemu, so I agree > with this... > > On the other hand the output should be a property which can be > configured individually for every sound card. I think it's desirable to > have a soundcard dedicated to one output method and a second one for a > different output method and let the guest OS decide on which cards the > sound will play. > > > Ff libvirt forceably disables the audio backend, now, and then future > > libvirt enables the pre-existing QEMU support for hotplug, existing VMs > > will be doomed. > > > > IOW, I don't think this patch is desirable. > > We could allow hotplug only if qemu will allow to specify the sound > output per-soundcard which would avoid this problem. I agree that having ability to configure distinct outputs per sound card might be useful, I don't think it is a blocking feature for hotplugging sound cards. ie, there's no reason why a user should not be able to unplug their current sound card, and plug in a new sound card for a running guests - they would only ever have 1 sound card present at a time in that scenario, so distinct outputs is not a requirement for that usecase. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
