On 5/13/20 12:32 PM, Michal Privoznik wrote:
On 5/13/20 4:48 PM, Daniel Henrique Barboza wrote:
On 5/12/20 11:52 AM, Michal Privoznik wrote:
[...]
I think the problem is simpler to handle in Libvirt when QEMU deprecates the old
format entirely. Otherwise the user will have to also keep track of Libvirt versions
to understand why the migration is failing here and there.
I think they will have to track both actually. They will have to track QEMU version, no argument there. But also Libvirt version - they minimal required version would have to be the one where Libvirt switches from old to the new API.
In that case, I believe that offering a XML knob to choose which NUMA mode
the user wants (like I mentioned in the previous message) is a good way to
mitigate the overall annoyance of the situation. It's simpler to add "mode='legacy'"
in the domain XML than to update Libvirt.
We can keep this mechanism option around until we're certain that (most) users
moved on to newer QEMU/Libvirt versions. Granted, some guests will end up
breaking when the option is deprecated anyway. At least this is a bit more of a
"controlled explosion" scenario.
Thanks,
DHB
Michal
