On Fri, Oct 05, 2018 at 11:38:14AM +0200, Andrea Bolognani wrote: > On Fri, 2018-10-05 at 09:54 +0100, Daniel P. Berrangé wrote: > > On Fri, Oct 05, 2018 at 10:34:33AM +0200, Jiri Denemark wrote: > > > But what if QEMU (or any other hypervisor) marks something (device > > > model, machine type) as deprecated and we use that deprecated value as > > > our default. Shouldn't we be able to tell about it to our users (here > > > runtime warnings could help) when they use such thing explicitly and > > > choose a different default value? That would help users with the > > > transition and once hypervisor drops support for it completely, fewer > > > existing domains will be affected since the recently created ones would > > > already use non-deprecated defaults. > > > > QEMU already emits warnings on stderr whenever something that is > > deprecated is used, and those end up in the libvirt log file for > > that guest. I don't think that we need to duplicate what QEMU > > is already reporting again. > > Warnings printed on stderr -> users and developers will actually > see them, be annoyed by them, eventually cave in and act upon them. > > Warnings written to a log -> nobody will notice them, until one day > things suddenly stop working apparently out of the blue. > > We might pretend that's not the case, but really, it is. Unless you're talking about a CLI tool (virt-install, virsh), there is no difference between those two scenarios. For virt-manager, virt-viewer, oVirt, OpenStack, KubeVirt, stderr is never going to be seen, it just ends up in a log file. So I don't find that distinction to be compelling. 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
