Re: [libvirt] [PATCH] allow memballoon type of none to desactivate it

On Mon, Aug 09, 2010 at 06:38:27PM +0200, Daniel Veillard wrote: > The balloon device is automatically added to qemu guests if supported, > but it may be useful to desactivate it. The simplest to not change the > existing behaviour is to allow > <memballoon type="none"/> > as an extra option to desactivate it (it is automatically added if the > memballoon construct is missing for the domain). > The following simple patch just adds the extra option and does not > change the default behaviour but avoid creating a balloon device if > type="none" is used. I really don't like the idea of 'type=none' devices in general.

I don't think we should have an element insides <devices> that doesn't actually represent a device. If we want to disable the balloon, then I think we should aim for an element or attribute elsewhere to toggle it. eg, perhaps the earlier <memory> element can indicate whether it supports ballooning. eg <memory ballonable='yes|no'>2423423432</memory> Thus if ballooning is not enabled, the <memballoon> device would never need to appear within <devices>