[libvirt-users] 100% CPU when using nested virtualization

Hi all, I got a new laptop recently and what worked before no longer works (Fedora 23 on the laptops in both cases)... I'm trying to get nested virtualization to work because I use the VMs on the laptop to simulate an HA cluster that itself hosts VMs. I don't care much at all about the performance of the nested VM, it's just there so that I can work on the cluster's code. When I try to provision a VM inside a VM (the host VM is CentOS/RHEL 6.7), the CPU load spikes to such a high degree that my ssh session times out after a while. The VM appears in libvirtd (as viewed by virt-manager on another machine), but the VM itself never starts. In one case, the VM host remained somewhat functional and killing kvm/qemu/libvirtd didn't reduce the CPU load. The main difference between the setups is that the older laptop had a Sandy bridge(? Thinkpad W530) and the new laptop is a Broadwell (Thinkpad P70). I've tried to loading vhost_net without much luck. I have, of course, enabled nesting on the actual hardware: cat /sys/module/kvm_intel/parameters/nested Y Any tips on how to debug? I'm in quite a pickle with this, so any and all help is much appreciated. -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education?