Re: [libvirt] [PATCH v2] kvm: warn if num cpus is greater than num recommended

> What I'm more worried about is what number is libvirt supposed to show > to the end user, and should libvirt enforce the lower recommended max, > or the larger kernel absolute max? Which of the two values does the QMP > 'MachineInfo' type return in its 'cpu-max' field during the > 'query-machines' command? Should we be modifying QMP to return both > values, so that libvirt can also expose the logic to the end user of > allowing a recommended vs. larger development max? > Machine definitions maintain yet another 'max_cpus'. And it appears that qmp would return that value. It would probably be best if it returned max(qemu_machine.max_cpus, kvm_max_cpus) though. I'm starting to think that we should just keep things simple for most of the virt stack by sticking to enforcing the larger developer max. And then on a production kernel we should just compile KVM_MAX_VCPUS = KVM_SOFT_MAX_VCPUS and be done with it. With that thought, this patch could be dropped too. The alternative seems to be supporting a run-time selectable experimental mode throughout the whole virt stack.