Re: [libvirt] [RFC PATCH 01/17] qemu: setup shared memory without explicit numa configuration

On Fri, Jul 13, 2018 at 03:28:08PM +0200, marcandre.lureau(a)redhat.com wrote: > From: Marc-André Lureau <marcandre.lureau(a)redhat.com&gt; > > When a domain is configured with 'shared' memory backing: > > <memoryBacking> > <access mode='shared'/> > </memoryBacking> > > But no explicit NUMA configuration, let's configure a shared memory > backend associated with default -numa. > diff --git a/tests/qemuxml2argvdata/fd-memory-no-numa-topology.args b/tests/qemuxml2argvdata/fd-memory-no-numa-topology.args > index bd88daaa3b..400fb39cc6 100644 > --- a/tests/qemuxml2argvdata/fd-memory-no-numa-topology.args > +++ b/tests/qemuxml2argvdata/fd-memory-no-numa-topology.args > @@ -11,6 +11,10 @@ QEMU_AUDIO_DRV=none \ > -m 14336 \ > -mem-prealloc \ > -smp 8,sockets=8,cores=1,threads=1 \ > +-object memory-backend-file,id=ram-node,\ > +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node,\ > +share=yes,size=15032385536 \ > +-numa node,nodeid=0,memdev=ram-node \ I'm not at all convinced it is safe todo this. We've been burnt in the past by adding use of memory-backend objects causing migration to break commit f309db1f4d51009bad0d32e12efc75530b66836b Author: Michal Privoznik <mprivozn(a)redhat.com&gt; Date: Thu Dec 18 12:36:48 2014 +0100 qemu: Create memory-backend-{ram,file} iff needed Libvirt BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1175397 QEMU BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1170093 This change doesn't really feel like it is required either. If the user wants NUMA, then the XML can just be written to request a NUMA topology with a single node. Better to be explicit in the XML rather than silently adding things as a side effect

Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list