Re: [Qemu-devel] [PATCH qemu v3 2/2] qmp: Add qom-list-properties to list QOM object properties

2018-03-01 Thread David Gibson 
On Fri, Mar 02, 2018 at 12:09:39AM +1100, Alexey Kardashevskiy wrote:
> There is already 'device-list-properties' which does most of the job,
> however it does not handle everything returned by qom-list-types such
> as machines as they inherit directly from TYPE_OBJECT and not TYPE_DEVICE.
> It does not handle abstract classes either.
> 
> This adds a new qom-list-properties command which prints properties
> of a specific class and its instance. It is pretty much a simplified copy
> of the device-list-properties handler.
> 
> Since it creates an object instance, device properties should appear
> in the output as they are copied to QOM properties at the instance_init
> hook.
> 
> This adds a object_class_property_iter_init() helper to allow class
> properties enumeration uses it in the new QMP command to allow properties
> listing for abstract classes.
> 
> Signed-off-by: Alexey Kardashevskiy 
> ---
> Changes:
> v3:
> * Used ObjectPropertyInfo instead of QOMPropertyInfo
> 
> v2:
> * added abstract classes support, now things like "pci-device" or
> "spapr-machine" show properties, previously these would produce
> an "abstract class" error
> 
> # Conflicts:
> # qapi-schema.json
> ---
>  qapi-schema.json | 15 +++
>  include/qom/object.h | 16 
>  qmp.c| 49 +
>  qom/object.c |  7 +++
>  4 files changed, 87 insertions(+)
> 
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 87327e5..32e836f 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1442,6 +1442,21 @@
>'returns': [ 'ObjectPropertyInfo' ] }
>  
>  ##
> +# @qom-list-properties:
> +#
> +# List properties associated with a QOM object.
> +#
> +# @typename: the type name of an object
> +#
> +# Returns: a list of ObjectPropertyInfo describing object properties
> +#
> +# Since: 2.12
> +##
> +{ 'command': 'qom-list-properties',
> +  'data': { 'typename': 'str'},
> +  'returns': [ 'ObjectPropertyInfo' ] }
> +
> +##
>  # @xen-set-global-dirty-log:
>  #
>  # Enable or disable the global dirty log mode.
> diff --git a/include/qom/object.h b/include/qom/object.h
> index dc73d59..ef07d78 100644
> --- a/include/qom/object.h
> +++ b/include/qom/object.h
> @@ -1017,6 +1017,22 @@ void object_property_iter_init(ObjectPropertyIterator 
> *iter,
> Object *obj);
>  
>  /**
> + * object_class_property_iter_init:
> + * @klass: the class
> + *
> + * Initializes an iterator for traversing all properties
> + * registered against an object class and all parent classes.
> + *
> + * It is forbidden to modify the property list while iterating,
> + * whether removing or adding properties.
> + *
> + * This can be used on abstract classes as it does not create a temporary
> + * instance.
> + */
> +void object_class_property_iter_init(ObjectPropertyIterator *iter,
> + ObjectClass *klass);
> +
> +/**
>   * object_property_iter_next:
>   * @iter: the iterator instance
>   *
> diff --git a/qmp.c b/qmp.c
> index 8a74038..1f15f68 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -576,6 +576,55 @@ ObjectPropertyInfoList *qmp_device_list_properties(const 
> char *typename,
>  return prop_list;
>  }
>  
> +ObjectPropertyInfoList *qmp_qom_list_properties(const char *typename,
> + Error **errp)
> +{
> +ObjectClass *klass;
> +Object *obj = NULL;
> +ObjectProperty *prop;
> +ObjectPropertyIterator iter;
> +ObjectPropertyInfoList *prop_list = NULL;
> +
> +klass = object_class_by_name(typename);
> +if (klass == NULL) {
> +error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
> +  "Class '%s' not found", typename);
> +return NULL;
> +}
> +
> +klass = object_class_dynamic_cast(klass, TYPE_OBJECT);
> +if (klass == NULL) {
> +error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "typename", 
> TYPE_OBJECT);
> +return NULL;
> +}
> +
> +if (object_class_is_abstract(klass)) {
> +object_class_property_iter_init(, klass);

I remain a bit concerned about the subtle difference in behaviour
between abstract and non-abstract classes.

> +} else {
> +obj = object_new(typename);
> +object_property_iter_init(, obj);
> +}
> +while ((prop = object_property_iter_next())) {
> +ObjectPropertyInfo *info;
> +ObjectPropertyInfoList *entry;
> +
> +info = g_malloc0(sizeof(*info));
> +info->name = g_strdup(prop->name);
> +info->type = g_strdup(prop->type);
> +info->has_description = !!prop->description;
> +info->description = g_strdup(prop->description);
> +
> +entry = g_malloc0(sizeof(*entry));
> +entry->value = info;
> +entry->next = prop_list;
> +prop_list = entry;
> +}
> +
> +object_unref(obj);
> +
> +return prop_list;
> +}
> +
>  CpuDefinitionInfoList

[Qemu-devel] [PATCH qemu v3 2/2] qmp: Add qom-list-properties to list QOM object properties

2018-03-01 Thread Alexey Kardashevskiy 
There is already 'device-list-properties' which does most of the job,
however it does not handle everything returned by qom-list-types such
as machines as they inherit directly from TYPE_OBJECT and not TYPE_DEVICE.
It does not handle abstract classes either.

This adds a new qom-list-properties command which prints properties
of a specific class and its instance. It is pretty much a simplified copy
of the device-list-properties handler.

Since it creates an object instance, device properties should appear
in the output as they are copied to QOM properties at the instance_init
hook.

This adds a object_class_property_iter_init() helper to allow class
properties enumeration uses it in the new QMP command to allow properties
listing for abstract classes.

Signed-off-by: Alexey Kardashevskiy 
---
Changes:
v3:
* Used ObjectPropertyInfo instead of QOMPropertyInfo

v2:
* added abstract classes support, now things like "pci-device" or
"spapr-machine" show properties, previously these would produce
an "abstract class" error

# Conflicts:
#   qapi-schema.json
---
 qapi-schema.json | 15 +++
 include/qom/object.h | 16 
 qmp.c| 49 +
 qom/object.c |  7 +++
 4 files changed, 87 insertions(+)

diff --git a/qapi-schema.json b/qapi-schema.json
index 87327e5..32e836f 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1442,6 +1442,21 @@
   'returns': [ 'ObjectPropertyInfo' ] }
 
 ##
+# @qom-list-properties:
+#
+# List properties associated with a QOM object.
+#
+# @typename: the type name of an object
+#
+# Returns: a list of ObjectPropertyInfo describing object properties
+#
+# Since: 2.12
+##
+{ 'command': 'qom-list-properties',
+  'data': { 'typename': 'str'},
+  'returns': [ 'ObjectPropertyInfo' ] }
+
+##
 # @xen-set-global-dirty-log:
 #
 # Enable or disable the global dirty log mode.
diff --git a/include/qom/object.h b/include/qom/object.h
index dc73d59..ef07d78 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -1017,6 +1017,22 @@ void object_property_iter_init(ObjectPropertyIterator 
*iter,
Object *obj);
 
 /**
+ * object_class_property_iter_init:
+ * @klass: the class
+ *
+ * Initializes an iterator for traversing all properties
+ * registered against an object class and all parent classes.
+ *
+ * It is forbidden to modify the property list while iterating,
+ * whether removing or adding properties.
+ *
+ * This can be used on abstract classes as it does not create a temporary
+ * instance.
+ */
+void object_class_property_iter_init(ObjectPropertyIterator *iter,
+ ObjectClass *klass);
+
+/**
  * object_property_iter_next:
  * @iter: the iterator instance
  *
diff --git a/qmp.c b/qmp.c
index 8a74038..1f15f68 100644
--- a/qmp.c
+++ b/qmp.c
@@ -576,6 +576,55 @@ ObjectPropertyInfoList *qmp_device_list_properties(const 
char *typename,
 return prop_list;
 }
 
+ObjectPropertyInfoList *qmp_qom_list_properties(const char *typename,
+ Error **errp)
+{
+ObjectClass *klass;
+Object *obj = NULL;
+ObjectProperty *prop;
+ObjectPropertyIterator iter;
+ObjectPropertyInfoList *prop_list = NULL;
+
+klass = object_class_by_name(typename);
+if (klass == NULL) {
+error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+  "Class '%s' not found", typename);
+return NULL;
+}
+
+klass = object_class_dynamic_cast(klass, TYPE_OBJECT);
+if (klass == NULL) {
+error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "typename", 
TYPE_OBJECT);
+return NULL;
+}
+
+if (object_class_is_abstract(klass)) {
+object_class_property_iter_init(, klass);
+} else {
+obj = object_new(typename);
+object_property_iter_init(, obj);
+}
+while ((prop = object_property_iter_next())) {
+ObjectPropertyInfo *info;
+ObjectPropertyInfoList *entry;
+
+info = g_malloc0(sizeof(*info));
+info->name = g_strdup(prop->name);
+info->type = g_strdup(prop->type);
+info->has_description = !!prop->description;
+info->description = g_strdup(prop->description);
+
+entry = g_malloc0(sizeof(*entry));
+entry->value = info;
+entry->next = prop_list;
+prop_list = entry;
+}
+
+object_unref(obj);
+
+return prop_list;
+}
+
 CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
 {
 return arch_query_cpu_definitions(errp);
diff --git a/qom/object.c b/qom/object.c
index 5dcee46..e7978bd 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1037,6 +1037,13 @@ ObjectProperty 
*object_property_iter_next(ObjectPropertyIterator *iter)
 return val;
 }
 
+void object_class_property_iter_init(ObjectPropertyIterator *iter,
+ ObjectClass *klass)
+{
+g_hash_table_iter_init(>iter,