Re: [libvirt] Non-contiguous NUMA cell numbers

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.

-- Andrea Bolognani Software Engineer - Virtualization Team