Allow setting the CPU model OR enabling nesting

[fabiand]

Sometimes - like with kubevirt we are running VMs with kubernetes. In that context we'd like to allow nesting, this requires libvirtd to use <cpu mode='host-model'> for the (minikube) VM.

It would be nice if there was a way to enable this.

[zakame]

For KVM nesting, I think docker-machine-kvm already passess in host-passthrough for the CPU (https://github.com/dhiltgen/docker-machine-kvm/blob/master/kvm.go#L40) so it would need only the host machine enabling nesting (e.g. option kvm_intel nested=y) in /etc/modprobe.d/kvm.conf.

[fabiand]

Hm. I am not sure why, but in minikube <cpu> is not used.

@gbraad any idea?

[gbraad]

KVM2 in minikube has diverged, so not sure why they dropped this. @aaron-prindle @r2d4 Any idea? But we are in the process to move this driver to a new home: #67 This might help for this situation...

[zakame]

Yes, The kvm2 driver doesn't provide options for CPUs other than setting the number to allocate to VM: https://github.com/kubernetes/minikube/blob/9fe915461445d340ec9272f3b043f75f42008ea5/pkg/drivers/kvm/kvm.go#L44

Currently it seems to do the bare minimum libvirt config only.

[fabiand]

Thanks @gbraad

Moving the minikube thread over to kubernetes/minikube#2553 @zakame @gbraad

[fabiand]

Actually, on this issues - I think we can close it, because - yes - docker machine has passthrough set which should be neough if the host is configured acccordingly.