Re: [PATCH 0/2] qemu: Switch to new -numa memdev=
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