[Qemu-devel] [PATCH] Introduce query-cpu-max QMP command and cpu_max HMP counterpart

* [Qemu-devel] [PATCH] Introduce query-cpu-max QMP command and cpu_max HMP counterpart
@ 2013-03-12 16:03 Michal Novotny
  2013-03-13 20:40 ` Eric Blake
                   ` (2 more replies)
  0 siblings, 3 replies; 10+ messages in thread
From: Michal Novotny @ 2013-03-12 16:03 UTC (permalink / raw)
  To: qemu-devel; +Cc: Michal Novotny

This is the patch to introduce the query-cpu-max QMP command to get
the maximum number of CPUs supported by the currently running emulator
instance. This may differ machine from machine as defined by -machine
settings and max_cpus member of QEMUMachine structure.

It's been tested both using QMP/qmp utility and telnet session on
the QEMU session.

The HMP counterpart called cpu_max has been introduced by this patch
too.

Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
 hmp-commands.hx  | 14 ++++++++++++++
 hmp.c            | 15 +++++++++++++++
 hmp.h            |  1 +
 qapi-schema.json | 11 +++++++++++
 qmp-commands.hx  | 22 ++++++++++++++++++++++
 vl.c             |  5 +++++
 6 files changed, 68 insertions(+)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 69c707d..b1224e3 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -690,6 +690,20 @@ Set the default CPU.
 ETEXI
 
     {
+        .name       = "cpu_max",
+        .args_type  = "",
+        .params     = "",
+        .help       = "Get maximum number of VCPUs supported by machine",
+        .mhandler.cmd = hmp_query_cpu_max,
+    },
+
+STEXI
+@item cpu_max
+@findex cpu_max
+Returns the number of CPUs supported by the machine being emulated.
+ETEXI
+
+    {
         .name       = "mouse_move",
         .args_type  = "dx_str:s,dy_str:s,dz_str:s?",
         .params     = "dx dy [dz]",
diff --git a/hmp.c b/hmp.c
index 2f47a8a..742f5c7 100644
--- a/hmp.c
+++ b/hmp.c
@@ -704,6 +704,21 @@ void hmp_ringbuf_read(Monitor *mon, const QDict *qdict)
     g_free(data);
 }
 
+void hmp_query_cpu_max(Monitor *mon, const QDict *qdict)
+{
+    int cpu_max;
+    Error *errp = NULL;
+
+    cpu_max = qmp_query_cpu_max(&errp);
+    if (errp) {
+        monitor_printf(mon, "%s\n", error_get_pretty(errp));
+        error_free(errp);
+        return;
+    }
+
+    monitor_printf(mon, "Maximum number of CPUs is %d\n", cpu_max);
+}
+
 static void hmp_cont_cb(void *opaque, int err)
 {
     if (!err) {
diff --git a/hmp.h b/hmp.h
index 30b3c20..f0c3352 100644
--- a/hmp.h
+++ b/hmp.h
@@ -41,6 +41,7 @@ void hmp_stop(Monitor *mon, const QDict *qdict);
 void hmp_system_reset(Monitor *mon, const QDict *qdict);
 void hmp_system_powerdown(Monitor *mon, const QDict *qdict);
 void hmp_cpu(Monitor *mon, const QDict *qdict);
+void hmp_query_cpu_max(Monitor *mon, const QDict *qdict);
 void hmp_memsave(Monitor *mon, const QDict *qdict);
 void hmp_pmemsave(Monitor *mon, const QDict *qdict);
 void hmp_ringbuf_write(Monitor *mon, const QDict *qdict);
diff --git a/qapi-schema.json b/qapi-schema.json
index 28b070f..e828839 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1832,6 +1832,17 @@
 { 'command': 'query-migrate-cache-size', 'returns': 'int' }
 
 ##
+## @query-cpu-max
+##
+## query maximum number of CPUs supported by machine
+##
+## Returns: number of CPUs
+##
+## Since: 1.5
+###
+{ 'command': 'query-cpu-max', 'returns': 'int' }
+
+##
 # @ObjectPropertyInfo:
 #
 # @name: the name of the property
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 95022e2..d29de4b 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -385,6 +385,28 @@ Note: CPUs' indexes are obtained with the 'query-cpus' command.
 EQMP
 
     {
+        .name       = "query-cpu-max",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_query_cpu_max,
+    },
+
+SQMP
+query-cpu-max
+-------------
+
+Get the maximum CPUs supported by the machine being currently
+emulated.
+
+Returns json-int.
+
+Example:
+
+-> { "execute": "query-cpu-max" }
+<- { "return": 255 }
+
+EQMP
+
+    {
         .name       = "memsave",
         .args_type  = "val:l,size:i,filename:s,cpu:i?",
         .mhandler.cmd_new = qmp_marshal_input_memsave,
diff --git a/vl.c b/vl.c
index 154f7ba..e04feb0 100644
--- a/vl.c
+++ b/vl.c
@@ -632,6 +632,11 @@ StatusInfo *qmp_query_status(Error **errp)
     return info;
 }
 
+int qmp_query_cpu_max(Error **errp)
+{
+    return current_machine->max_cpus;
+}
+
 /***********************************************************/
 /* real time host monotonic timer */
 
-- 
1.7.11.7

^ permalink raw reply related	[flat|nested] 10+ messages in thread