On Thu, Sep 06, 2012 at 14:03:14 -0400, sanjay wrote:

Hi! When only the vCPU tag is specified, libvirt by default generates a multi-socket topology(sockets=vCPUs,cores=1,threads=1) for the qemu command line. Is there a specific reason behind choice of this default behavior? Could a default of (socket=1,cores=vCPUs,threads=1) would have been a better choice ?

We need to maintain backward compatibility. Changing it would mean that guest without topology configuration would suddenly see different CPU topology and that could confuse them or even invalidate SW licences and similar beasts. If you want different topology, you need to explicitly specify it in the XML. Jirka