n Mon, 2016-01-04 at 07:57 +0100, Michal Privoznik wrote:
On 23.12.2015 17:14, Andrea Bolognani wrote:
Hi all, libvirt currently doesn't allow you to configure a guest with something like <cpu> <topology sockets='2' cores='5' threads='8'/> <numa> <cell id='0' cpus='0-39' memory='1048576' unit='KiB'/> <cell id='16' cpus='40-79' memory='1048576' unit='KiB'/> </numa> This says you are configuring GUEST NUMA nodes, and last time I checked qemu did not support non-continuous NUMA nodes. So, whatever your HOST topology is, in GUEST you want NUMA nodes to be continuous.
I checked again and, as you and Daniel suggested, QEMU does not support non-contiguous NUMA nodes, eg. qemu-kvm \ -m 2048 \ -smp 80,sockets=2,cores=5,threads=8 \ -numa node,nodeid=0,cpus=0-39,mem=1024 \ -numa node,nodeid=16,cpus=40-79,mem=1024 outputs qemu-kvm: numa: Node ID missing: 15 so indeed there's a very good reason for libvirt to reject that NUMA configuration. Cheers. -- Andrea Bolognani Software Engineer - Virtualization Team