On 08/27/13 11:44, Peeyush Gupta wrote: Hi, libvirt-1.0.2 contains an extended output [1] in the capabilities XML that closer describes the individual CPUs seen by libvirt. This data can then be used to extract data about the host topology. I'll try to find and add to examples a python script that can be used to do the calculation from the data in the capabilities XML. Peter [1]: commit 828820e2d371205d6a6061301165d58a1a92e611 Author: Peter Krempa <pkrempa(a)redhat.com&gt; Date: Fri Jan 18 19:30:00 2013 +0100 schemas: Add schemas for more CPU topology information in the caps XML This patch adds RNG schemas for adding more information in the topology output of the NUMA section in the capabilities XML. The added elements are designed to provide more information about the placement and topology of the processors in the system to management applications. A demonstration of supported XML added by this patch: <capabilities> <host> <topology> <cells num='3'> <cell id='0'> <cpus num='4'> <!-- this is node with Hyperthreading --> <cpu id='0' socket_id='0' core_id='0' siblings='0-1'/> <cpu id='1' socket_id='0' core_id='0' siblings='0-1'/> <cpu id='2' socket_id='0' core_id='1' siblings='2-3'/> <cpu id='3' socket_id='0' core_id='1' siblings='2-3'/> </cpus> </cell> <cell id='1'> <cpus num='4'> <!-- this is node with modules (Bulldozer) --> <cpu id='4' socket_id='0' core_id='2' siblings='4-5'/> <cpu id='5' socket_id='0' core_id='3' siblings='4-5'/> <cpu id='6' socket_id='0' core_id='4' siblings='6-7'/> <cpu id='7' socket_id='0' core_id='5' siblings='6-7'/> </cpus> </cell> <cell id='2'> <cpus num='4'> <!-- this is a normal multi-core node --> <cpu id='8' socket_id='1' core_id='0' siblings='8'/> <cpu id='9' socket_id='1' core_id='1' siblings='9'/> <cpu id='10' socket_id='1' core_id='2' siblings='10'/> <cpu id='11' socket_id='1' core_id='3' siblings='11'/> </cpus> </cell> </cells> </topology> </host> </capabilities> The socket_id field represents identification of the physical socket the CPU is plugged in. This ID may not be identical to the physical socket ID reported by the kernel. The core_id identifies a core within a socket. Also this field may not accurately represent physical ID's. The core_id is guaranteed to be unique within a cell and a socket. There may be duplicates between sockets. Only cores sharing core_id within one cell and one socket can be considered as threads. Cores sharing core_id within sparate cells are distinct cores. The siblings field is a list of CPU id's the cpu id's the CPU is sibling with - thus a thread. The list is in the cpuset format.