Re: [Qemu-devel] [PATCH for-2.10 08/23] virt-arm: add node-id property to CPU

[Igor Mammedov]

On Tue, 25 Apr 2017 19:16:13 +0200
Andrew Jones <address@hidden> wrote:

> On Wed, Mar 22, 2017 at 02:32:33PM +0100, Igor Mammedov wrote:
> > it will allow switching from cpu_index to property based
> > numa mapping in follow up patches.
> > 
> > Signed-off-by: Igor Mammedov <address@hidden>
> > ---
> >  hw/arm/virt.c    | 15 +++++++++++++++
> >  target/arm/cpu.c |  1 +
> >  2 files changed, 16 insertions(+)
> > 
> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> > index 8748d25..68d44f3 100644
> > --- a/hw/arm/virt.c
> > +++ b/hw/arm/virt.c
> > @@ -1365,6 +1365,7 @@ static void machvirt_init(MachineState *machine)
> >      for (n = 0; n < machine->possible_cpus->len; n++) {
> >          Object *cpuobj;
> >          CPUState *cs;
> > +        int node_id;
> >  
> >          if (n >= smp_cpus) {
> >              break;
> > @@ -1377,6 +1378,20 @@ static void machvirt_init(MachineState *machine)
> >          cs = CPU(cpuobj);
> >          cs->cpu_index = n;
> >  
> > +        node_id = numa_get_node_for_cpu(cs->cpu_index);
> > +        if (node_id == nb_numa_nodes) {
> > +            /* by default CPUState::numa_node was 0 if it's not set via CLI
> > +             * keep it this way for now but in future we probably should
> > +             * refuse to start up with incomplete numa mapping */
> > +             node_id = 0;  
> 
> Do other architectures already abort on incomplete numa? If so, it'd be
> nice to do that for mach-virt sooner than later. I guess we just need
> another compat variable for 2.9 and older machine types.  I think libvirt
> always supplies all cpu-node mappings, if any, so there shouldn't be an
> issue with it.
so far we only print warning messages but allow to proceed (it global policy),
intent was that further down the road we would obsolete it and turn them in
hard errors (maybe without keeping even compat stuff).
I guess we can do it for all supported archs at the same time in 2-3 releases
after announcing it (patch 20/23 adds obsoleted message).

> 
> Thanks,
> drew