[libvirt-users] Getting CPU and memory usage statistics for the host

Hi, I have noticed that virt-manager has the ability to show me the current cpu- and memory-usage of both the host and running guest machines. How does it do that? I could make good use of that information myself in the client applications I'm writing, however, from what I can see on http://libvirt.org/html/libvirt-libvirt.html, I have no idea how to go about getting it from libvirt. In fact, before I've seen virt-manager, I just assumed libvirt cannot do that at all, and was planning to manually ssh to the host and read statistics from /proc when I'd need them. I've tried looking at the virt-manager source code to find out how to do this, but it appears I would have to learn Python first in order to understand it. Could someone please give me some pointers? Regards, Guido