On 13/07/2016 09:30, Igor Mammedov wrote: > I wonder if it could be cleaner to extend QOM API with > > object_get_refcount(); > > and then add > > bool hostmem_is_busy() > { > return object_get_refcount() > 1; > } > > that would work as not used used hostmem would have ref counter == 1 > and when front-end starts to use it, it calls > qdev_prop_allow_set_link_before_realize() > which rises ref counter of backend to 2. > > Also see a comment below. I disagree---there are many reasons why a refcount can be > 1, and given that we use RCU the release of the reference can be delayed arbitrarily. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html