On Wed, Jan 27, 2021 at 04:35:22PM +0100, Igor Mammedov wrote: > On Wed, 27 Jan 2021 15:24:26 +0100 > Michal Privoznik <mpriv...@redhat.com> wrote: > > > On 1/27/21 11:54 AM, Daniel P. Berrangé wrote: > > > On Wed, Jan 27, 2021 at 10:45:11AM +0000, Daniel P. Berrangé wrote: > > >> On Thu, Jan 21, 2021 at 11:15:04AM -0500, Igor Mammedov wrote: > > > > > > >> > > >> How does a mgmt app know which machine types need to use this > > >> option ? The machine type names are opaque strings, and apps > > >> must not attempt to parse or interpret the version number > > >> inside the machine type name, as they can be changed by > > >> distros. IOW, saying to use it for machine types 4.0 and > > >> older isn't a valid usage strategy IMHO. > it's possible (but no necessary) to use knob with new machine types > (defaults for these match suggested property value).
IIUC, this means that setting the property has no impact on migration ABI for new machine types > 4.0.... > Limiting knob usage to 4.0 and older would allow us to drop > without extra efforts once 4.0 is deprecated/removed. ...so, even if we set the property unconditionally for *all* machine types, then we can still remove it in future, becuase its removal won't affect ABI of the 5.x, 6.x machine types. 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 :|
