Re: [Qemu-devel] [RFC 0/6] enable numa configuration before machine_init() from HMP/QMP

[Eduardo Habkost]

On Mon, Oct 16, 2017 at 05:36:36PM +0100, Daniel P. Berrange wrote:
> On Mon, Oct 16, 2017 at 06:22:50PM +0200, Igor Mammedov wrote:
> > Series allows to configure NUMA mapping at runtime using QMP/HMP
> > interface. For that to happen it introduces a new '-paused' CLI option
> > which allows to pause QEMU before machine_init() is run and
> > adds new set-numa-node HMP/QMP commands which in conjuction with
> > info hotpluggable-cpus/query-hotpluggable-cpus allow to configure
> > NUMA mapping for cpus.
> 
> What's the problem we're seeking solve here compared to what we currently
> do for NUMA configuration ?

I don't understand completely what exactly Igor is trying to
solve, but this new mode would be very helpful to address the
issues mentioned at:

http://www.linux-kvm.org/images/4/46/03x06A-Eduardo_HabkostMachine-type_Introspection_and_Configuration_Where_Are_We_Going.pdf
(starting on slide 12)

> 
> > 
> > HMP configuration session for CLI '-smp 1,maxcpus=2' would look like:
> > 
> > (qemu) info hotpluggable-cpus 
> > Hotpluggable CPUs:
> >   type: "qemu64-x86_64-cpu"
> >   vcpus_count: "1"
> >   CPUInstance Properties:
> >     socket-id: "1"
> >     core-id: "0"
> >     thread-id: "0"
> >   type: "qemu64-x86_64-cpu"
> >   vcpus_count: "1"
> >   qom_path: "/machine/unattached/device[0]"
> >   CPUInstance Properties:
> >     socket-id: "0"
> >     core-id: "0"
> >     thread-id: "0"
> > (qemu) set-numa-node node,nodeid=0
> > (qemu) set-numa-node node,nodeid=1
> > (qemu) set-numa-node cpu,socket-id=0,node-id=0
> > (qemu) set-numa-node cpu,socket-id=1,node-id=1
> > (qemu) info hotpluggable-cpus 
> > Hotpluggable CPUs:
> >   type: "qemu64-x86_64-cpu"
> >   vcpus_count: "1"
> >   CPUInstance Properties:
> >     node-id: "1"
> >     socket-id: "1"
> >     core-id: "0"
> >     thread-id: "0"
> >   type: "qemu64-x86_64-cpu"
> >   vcpus_count: "1"
> >   CPUInstance Properties:
> >     node-id: "0"
> >     socket-id: "0"
> >     core-id: "0"
> >     thread-id: "0"
> > (qemu) cont
> > 
> > git tree for testing:
> >   https://github.com/imammedo/qemu qmp_preconfig_rfc
> > 
> > 
> > CC: address@hidden
> > CC: address@hidden
> > CC: address@hidden
> > CC: address@hidden
> > CC: address@hidden
> > CC: address@hidden
> > CC: address@hidden
> > CC: address@hidden
> > 
> > Igor Mammedov (6):
> >   numa: postpone options post-processing till machine_run_board_init()
> >   numa: split out NumaOptions parsing into parse_NumaOptions()
> >   possible_cpus: add CPUArchId::type field
> >   CLI: add -paused option
> >   HMP: add set-numa-node command
> >   QMP: add set-numa-node command
> > 
> >  hmp.h                      |  1 +
> >  include/hw/boards.h        |  2 ++
> >  include/sysemu/numa.h      |  2 ++
> >  include/sysemu/sysemu.h    |  1 +
> >  hmp-commands.hx            | 13 ++++++++
> >  hmp.c                      | 23 ++++++++++++++
> >  hw/arm/virt.c              |  3 +-
> >  hw/core/machine.c          | 18 ++++++-----
> >  hw/i386/pc.c               |  4 ++-
> >  hw/ppc/spapr.c             | 13 +++++---
> >  hw/s390x/s390-virtio-ccw.c |  1 +
> >  numa.c                     | 79 
> > ++++++++++++++++++++++++++++++++++------------
> >  qapi-schema.json           | 13 ++++++++
> >  qemu-options.hx            | 15 +++++++++
> >  qmp.c                      |  5 +++
> >  vl.c                       | 54 ++++++++++++++++++++++++++++++-
> >  16 files changed, 210 insertions(+), 37 deletions(-)
> > 
> > -- 
> > 2.7.4
> > 
> > 
> 
> Regards,
> Daniel
> -- 
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-- 
Eduardo