[Libvir] Extending libvirt to probe NUMA topology

[Ryan Harper]

Hello all,

I wanted to start a discussion on how we might get libvirt to be able to
probe the NUMA topology of Xen and Linux (for QEMU/KVM).  In Xen, I've
recently posted patches for exporting topology into the [1]physinfo
hypercall, as well adding a [2]hypercall to probe the Xen heap.  I
believe the topology and memory info is already available in Linux.
With these, we have enough information to be able to write some simple
policy above libvirt that can create guests in a NUMA-aware fashion.

I'd like to suggest the following for discussion:

(1) A function to discover topology
(2) A function to check available memory
(3) Specifying which cpus to use prior to domain start

Thoughts?

1. http://lists.xensource.com/archives/html/xen-devel/2007-06/msg00298.html 
2. http://lists.xensource.com/archives/html/xen-devel/2007-06/msg00299.html

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
(512) 838-9253   T/L: 678-9253
ryanh at us.ibm.com