[Qemu-devel] [PATCH v2 1/5] QMP: add query-hotpluggable-cpus

[Igor Mammedov <imammedo@redhat.com>]

it will allow mgmt to query present and possible to hotplug
CPU objects, it is required from a target platform that
wish to support command to implement
 qmp_query_hotpluggable_cpus()
functioni, which will return a list of possible CPU objects
with options that would be needed for hotplugging possible
CPU objects.

For RFC there are:
'type': 'str' - OQOM CPU object type for usage with device_add

and a set of optional fields that are to used for hotplugging
a CPU objects and would allows mgmt tools to know what/where
it could be hotplugged;
[node],[socket],[core],[thread]

For present CPUs there is a 'qom-path' field which
would allow mgmt inspect whatever object/abstraction
the target platform considers as CPU object.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 qapi-schema.json                    | 39 +++++++++++++++++++++++++++++++++++++
 qmp-commands.hx                     | 34 ++++++++++++++++++++++++++++++++
 stubs/Makefile.objs                 |  1 +
 stubs/qmp_query_hotpluggable_cpus.c |  9 +++++++++
 4 files changed, 83 insertions(+)
 create mode 100644 stubs/qmp_query_hotpluggable_cpus.c

diff --git a/qapi-schema.json b/qapi-schema.json
index 362c9d8..c59840d 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4122,3 +4122,42 @@
 ##
 { 'enum': 'ReplayMode',
   'data': [ 'none', 'record', 'play' ] }
+
+##
+# CpuInstanceProps
+#
+# @node: NUMA node ID the CPU belongs to, optional
+# @socket: socket number within node/board the CPU belongs to, optional
+# @core: core number within socket the CPU belongs to, optional
+# @thread: thread number within core the CPU belongs to, optional
+#
+# Since: 2.7
+{ 'struct': 'CpuInstanceProps',
+  'data': { '*node': 'int',
+            '*socket': 'int',
+            '*core': 'int',
+            '*thread': 'int'
+  }
+}
+
+##
+# @HotpluggableCPU
+#
+# @type: CPU object type for usage with device_add command
+# @qom-path: link to existing CPU object if CPU is present or
+#            omitted if CPU is not present.
+# @props: list of properties to be used for hotplugging CPU
+#
+# Since: 2.7
+{ 'struct': 'HotpluggableCPU',
+  'data': { 'type': 'str',
+            '*qom-path': 'str',
+            '*props': 'CpuInstanceProps'
+          }
+}
+
+##
+# @query-hotpluggable-cpus
+#
+# Since: 2.6
+{ 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index b629673..39687ad 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4853,3 +4853,37 @@ Example:
                  {"type": 0, "out-pport": 0, "pport": 0, "vlan-id": 3840,
                   "pop-vlan": 1, "id": 251658240}
    ]}
+
+EQMP
+
+    {
+        .name       = "query-hotpluggable-cpus",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_query_hotpluggable_cpus,
+    },
+
+SQMP
+Show  existing/possible CPUs
+-------------------------------
+
+Arguments: None.
+
+Example for x86 target started with -smp 2,sockets=2,cores=1,threads=3,maxcpus=6:
+
+-> { "execute": "query-hotpluggable-cpus" }
+<- {"return": [
+     {"core": 0, "socket": 1, "thread": 2}, "type": "qemu64-x86_64-cpu"},
+     {"core": 0, "socket": 1, "thread": 1}, "type": "qemu64-x86_64-cpu"},
+     {"core": 0, "socket": 1, "thread": 0}, "type": "qemu64-x86_64-cpu"},
+     {"core": 0, "socket": 0, "thread": 2}, "type": "qemu64-x86_64-cpu"},
+     {"core": 0, "socket": 0, "thread": 1}, "type": "qemu64-x86_64-cpu", "qom-path": "/machine/unattached/device[3]"},
+     {"core": 0, "socket": 0, "thread": 0}, "type": "qemu64-x86_64-cpu", "qom-path": "/machine/unattached/device[0]"}
+   ]}'
+
+Example for SPAPR target started with -smp 2,cores=2,maxcpus=4:
+
+-> { "execute": "query-hotpluggable-cpus" }
+<- {"return": [
+     {"core": 1 }, "type": "spapr-cpu-core"},
+     {"core": 0 }, "type": "spapr-cpu-core", "qom-path": "/machine/unattached/device[0]"}
+   ]}'
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index e922de9..0011173 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -39,3 +39,4 @@ stub-obj-y += qmp_pc_dimm_device_list.o
 stub-obj-y += target-monitor-defs.o
 stub-obj-y += target-get-monitor-def.o
 stub-obj-y += vhost.o
+stub-obj-y += qmp_query_hotpluggable_cpus.o
diff --git a/stubs/qmp_query_hotpluggable_cpus.c b/stubs/qmp_query_hotpluggable_cpus.c
new file mode 100644
index 0000000..21a75a3
--- /dev/null
+++ b/stubs/qmp_query_hotpluggable_cpus.c
@@ -0,0 +1,9 @@
+#include "qemu/osdep.h"
+#include "qapi/qmp/qerror.h"
+#include "qmp-commands.h"
+
+HotpluggableCPUList *qmp_query_hotpluggable_cpus(Error **errp)
+{
+    error_setg(errp, QERR_FEATURE_DISABLED, "query-hotpluggable-cpus");
+    return NULL;
+}
-- 
1.8.3.1