[pve-devel] [PATCH qemu-server] Fix: cpu hotplug feature can't be changed online

[DERUMIER, Alexandre]

Am 10.10.23 um 17:37 schrieb Alexandre Derumier:
> The cpus are passed as devices with specific id only when cpu hotplug
> is enable
> at start.
> We can't enable/disable it online or vcpu hotplug api will thrown
> errors
> not finding core id.

>>When removing cores after enabling the option this is true, but I can
>>1. start a VM without CPU hotplug and fewer than max vCPUs
>>2. enable CPU hotplug
>>3. add more cores

>>And doing the disable of the option online also doesn't seem
>>problematic
>>at a first glance. So I thought this would technically be a breaking
>>change.

Note that is also breaking unplug of cores present before enable
hotplug

>>1. start a VM without CPU hotplug and fewer than max vCPUs
>>2. enable CPU hotplug
>>3. remove cores



(But yes, the more important is migration breaking)