On Tue, Feb 21, 2017 at 15:36:23 +0000, Daniel Berrange wrote:
On Tue, Feb 21, 2017 at 04:22:05PM +0100, Peter Krempa wrote:
Memory-less numa nodes could be specified by setting the memory size to 0. Allow ommiting of the parameter completely to specify the same.
Partially resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1217144
Does this correctly plumb through to the guest OS ?
Last time we tried fixing this bug we found some problems - I can't remember whether the problem was with 0 CPUs or 0 memory, but with one of them, QEMU would totally mangle the NUMA topology, merging nodes together.
I tried it and indeed the NUMA topology for a memory-less node shows up totally broken in the guest. From your comments on the linked bugzilla I thought that it worked properly if you specify memory='0' explicitly. Since cpu-less nodes are possible for a long time and with the new cpu-hotplug API you can select individual vcpus to hotplug according to the id I was under the impression that only the syntax-sugar stuff was necessary to cover everyting.