[pve-devel] [PATCH pve-manager] qemu: bump max cores to 256 by socket

DERUMIER, Alexandre alexandre.derumier at groupe-cyllene.com
Mon Jan 15 13:43:20 CET 2024

>>mhmm.. in the backend we don't actually have a limit, maybe it's time
>>to remove the limit in the ui
>>altogether? it does not help anyway:

>>for numbers that are not too big (too many for qemu, too many for the
>>it's not the right limit (qemu) or we don't know at that point in the
>>gui (host cores)

>>but in case next year there is e.g. a 512 core machine, the limit is
>>too low again...

>>so i'd be either for
>>* removing the limit at all
>>* limit to the qemu limits (but maybe also in the backend?)
>>* use the number of cores of the current host as limit in the gui
>>(should be possible, but an 
>>additional api call)
>>what do you think?

Yes, indeed the backend don't have any limit.

We could indeed remove the limit in the gui.

I think we shouldn't limit based on the current host, as anyway, we can
create && migrate the vm on antoher host just after the create.

Maybe an improvement in qemu-server, could be to add additional check
at vm start, (maybe a simple warn), depending of qemu version or
For example, 1024 cores only works with q35 && qemu 8.1,
it could be interesting to give an clean hint  mesage to user instead
a qemu process error.

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