Reference virt.

cloudcontrol/node/hypervisor/domains/vm_tags.py

@@ -84,7 +84,7 @@ def cpuuse(dom):
         return None
     old_cpu_stats = dom.cpu_stats
     dom.cpu_stats = (dom.hypervisor.handler.main.evloop.now(), cpu_time)
-    # calculate CPU percentage
+    # calculate CPU percentage, code is from virt-manager in domain.py:1210
     return '%.2f' % max(0., min(100., ((cpu_time - old_cpu_stats[1]) * 100.) / (
         (dom.cpu_stats[0] - old_cpu_stats[0]) * 1000. * 1000. * 1000.)))