Hi Dan, > I do not compare CPUs for fun, but rather to know if a guest can be run > on a specific host. However, this is not exactly what > virConnectCompareCPU gives me: A vmx-enabled host cpu is a superset of > itself, but it would not run itself as a guest since we do not have > nested vxm yet. Similarly, if we ever have svm-emulation-by-kvm, we > could be running svm guests on a vmx host. > > Is it only me? Or should libvirt expose the more interesting meaning? Absolutely, that would be just perfect. However, I believe libvirt does the best it can. Only hypervisor itself knows that it can emulate some features which are not present in host CPU or that some features cannot work in guests even though host CPU provides them. For such advanced comparison, qemu would need to provide a way for libvirt to ask for this stuff. Jirka -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list