[Qemu-devel] [PATCH v3 0/9] enable numa configuration before machine_init() from QMP

[Igor Mammedov]

v1->v3:
  * introduce PRECONFIG runstate with -preconfig option.
    it's cleaner to manage transitions and do checks
    than reusing existing PRELAUNCH state.
  * extend QAPI schema commands with 'runstates' keyword,
    so that it would be possible to specify in command definition
    when it is valid to execute.
    (python changes a bit hackery, since I have little to
     no idea how it should work)
  * add preconfig QMP and set-numa-node tests
  * make mutually exclusive -preconfig and -incoming options,
    for simplicity sake. Shouldn't be problem as target can
    be starter with pure CLI, since mapping on source is
    already known.
  * Drop HMP part and leave only QMP in preconfig state.


Series allows to configure NUMA mapping at runtime using QMP
interface. For that to happen it introduces a new '-preconfig' CLI option
which allows to pause QEMU before machine_init() is run and
adds new set-numa-node QMP command which in conjunction with
query-hotpluggable-cpus allows to configure NUMA mapping for cpus.

Later we can modify other commands to run early, for example device_add.
I recall SPAPR had problem when libvirt started QEMU with -S and, while it's
paused, added CPUs with device_add. Intent was to coldplug CPUs (but at that
stage it's considered hotplug already), so SPAPR had to work around the issue.

Example of configuration session:
$QEMU -smp 2 -preconfig ...

QMP:
# get CPUs layout for current target/machine/CLI
-> {'execute': 'query-hotpluggable-cpus' }
<- {'return': [
       {'props': {'core-id': 0, 'thread-id': 0, 'socket-id': 1}, ... },
       {'props': {'core-id': 0, 'thread-id': 0, 'socket-id': 0}, ... }
   ]}

# configure 1st node
-> {'execute': 'set-numa-node', 'arguments': { 'type': 'node', 'nodeid': 0 } }
<- {'return': {}}
-> {'execute': 'set-numa-node', 'arguments': { 'type': 'cpu', 
       'node-id': 0, 'core-id': 0, 'thread-id': 0, 'socket-id': 1, }
   }
<- {'return': {}}

# configure 2nd node
-> {'execute': 'set-numa-node', 'arguments': { 'type': 'node', 'nodeid': 1 } }
-> {'execute': 'set-numa-node', 'arguments': { 'type': 'cpu',
       'node-id': 1, 'core-id': 0, 'thread-id': 0, 'socket-id': 0 }
   }
<- {'return': {}}

# [optional] verify configuration
-> {'execute': 'query-hotpluggable-cpus' }
<- {'return': [
       {'props': {'core-id': 0, 'thread-id': 0, 'node-id': 0, 'socket-id': 1}, 
... },
       {'props': {'core-id': 0, 'thread-id': 0, 'node-id': 1, 'socket-id': 0}, 
... }
   ]}


Git tree:
    https://github.com/imammedo/qemu.git qmp_preconfig_v3

Ref to v1:
    https://lists.gnu.org/archive/html/qemu-devel/2017-10/msg03583.html
    Message-Id: <address@hidden>
  
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Igor Mammedov (9):
  numa: postpone options post-processing till machine_run_board_init()
  numa: split out NumaOptions parsing into parse_NumaOptions()
  CLI: add -preconfig option
  HMP: disable monitor in preconfig state
  QAPI: allow to specify valid runstates per command
  tests: extend qmp test with pereconfig checks
  QMP: permit query-hotpluggable-cpus in preconfig state
  QMP: add set-numa-node command
  tests: functional tests for QMP command set-numa-node

 include/qapi/qmp/dispatch.h             |  5 ++-
 include/sysemu/numa.h                   |  2 +
 include/sysemu/sysemu.h                 |  1 +
 hw/core/machine.c                       |  5 ++-
 monitor.c                               | 32 +++++++++++++--
 numa.c                                  | 66 +++++++++++++++++++-----------
 qapi-schema.json                        | 32 +++++++++++++--
 qapi/qmp-dispatch.c                     | 39 ++++++++++++++++++
 qapi/qmp-registry.c                     |  4 +-
 qapi/run-state.json                     |  9 ++++-
 qemu-options.hx                         | 11 +++++
 qmp.c                                   |  5 +++
 scripts/qapi-commands.py                | 46 ++++++++++++++++-----
 scripts/qapi-introspect.py              |  2 +-
 scripts/qapi.py                         | 15 ++++---
 scripts/qapi2texi.py                    |  2 +-
 tests/numa-test.c                       | 71 +++++++++++++++++++++++++++++++++
 tests/qapi-schema/doc-good.out          |  4 +-
 tests/qapi-schema/ident-with-escape.out |  2 +-
 tests/qapi-schema/indented-expr.out     |  4 +-
 tests/qapi-schema/qapi-schema-test.out  | 18 ++++-----
 tests/qapi-schema/test-qapi.py          |  6 +--
 tests/qmp-test.c                        | 56 ++++++++++++++++++++++++++
 vl.c                                    | 35 +++++++++++++++-
 24 files changed, 401 insertions(+), 71 deletions(-)

-- 
2.7.4