On Wed, Nov 23, 2022 at 01:45:37PM +0000, Daniel P. Berrangé wrote:
Indeed, the very fact that libvirt exists and is widely used, is what allows QEMU to deprecated and rename stuff on a pretty aggressive schedule. If libvirt wasn't providing this isolation, then it is unlikely QEMU would have adopted its 2 release deprecated cycle, and would be locked into their mistakes for a much longer period.
My understanding was that qemu no longer change existing CPU model definitions, but instead introduce new versions (like IcelakeServer-V6), and that's how they can make changes as needed. Or are they still arbitrarily changing/breaking *existing* definitions in incompatible ways?
IOW, libvirt is allowing QEMU to fix their own technical debt on a more aggressive timeframe, albeit at some cost to libvirt maintainers.
I'd be interested in one or two specific examples so I can understand this properly. thanks john