[Qemu-devel] [PATCH v3 6/7] qmp: print descriptions of object properties

[arei.gonglei]

From: Gonglei <address@hidden>

Add a new "description" field to DevicePropertyInfo.
The descriptions can serve as documentation in the code,
and they can be used to provide better help. For example:

$./qemu-system-x86_64 -device virtio-blk-pci,?

Before this patch:

virtio-blk-pci.iothread=link<iothread>
virtio-blk-pci.x-data-plane=bool
virtio-blk-pci.scsi=bool
virtio-blk-pci.config-wce=bool
virtio-blk-pci.serial=str
virtio-blk-pci.secs=uint32
virtio-blk-pci.heads=uint32
virtio-blk-pci.cyls=uint32
virtio-blk-pci.discard_granularity=uint32
virtio-blk-pci.bootindex=int32
virtio-blk-pci.opt_io_size=uint32
virtio-blk-pci.min_io_size=uint16
virtio-blk-pci.physical_block_size=uint16
virtio-blk-pci.logical_block_size=uint16
virtio-blk-pci.drive=str
virtio-blk-pci.virtio-backend=child<virtio-blk-device>
virtio-blk-pci.command_serr_enable=on/off
virtio-blk-pci.multifunction=on/off
virtio-blk-pci.rombar=uint32
virtio-blk-pci.romfile=str
virtio-blk-pci.addr=pci-devfn
virtio-blk-pci.event_idx=on/off
virtio-blk-pci.indirect_desc=on/off
virtio-blk-pci.vectors=uint32
virtio-blk-pci.ioeventfd=on/off
virtio-blk-pci.class=uint32

After:

virtio-blk-pci.iothread=link<iothread>
virtio-blk-pci.x-data-plane=bool (on/off)
virtio-blk-pci.scsi=bool (on/off)
virtio-blk-pci.config-wce=bool (on/off)
virtio-blk-pci.serial=str
virtio-blk-pci.secs=uint32
virtio-blk-pci.heads=uint32
virtio-blk-pci.cyls=uint32
virtio-blk-pci.discard_granularity=uint32
virtio-blk-pci.bootindex=int32
virtio-blk-pci.opt_io_size=uint32
virtio-blk-pci.min_io_size=uint16
virtio-blk-pci.physical_block_size=uint16 (A power of two between 512 and 32768)
virtio-blk-pci.logical_block_size=uint16 (A power of two between 512 and 32768)
virtio-blk-pci.drive=str (ID of a drive to use as a backend)
virtio-blk-pci.virtio-backend=child<virtio-blk-device>
virtio-blk-pci.command_serr_enable=bool (on/off)
virtio-blk-pci.multifunction=bool (on/off)
virtio-blk-pci.rombar=uint32
virtio-blk-pci.romfile=str
virtio-blk-pci.addr=int32 (Slot and function number, example: 06.0)
virtio-blk-pci.event_idx=bool (on/off)
virtio-blk-pci.indirect_desc=bool (on/off)
virtio-blk-pci.vectors=uint32
virtio-blk-pci.ioeventfd=bool (on/off)
virtio-blk-pci.class=uint32

Cc: Paolo Bonzini <address@hidden>
Cc: Michael S. Tsirkin <address@hidden>
Cc: Markus Armbruster <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
 qapi-schema.json |  3 ++-
 qdev-monitor.c   |  7 ++++++-
 qmp.c            | 12 +++++++++---
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/qapi-schema.json b/qapi-schema.json
index 4bfaf20..04b7e62 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1615,11 +1615,12 @@
 #
 # @name: the name of the property
 # @type: the typename of the property
+# @description: the description of the property
 #
 # Since: 1.2
 ##
 { 'type': 'DevicePropertyInfo',
-  'data': { 'name': 'str', 'type': 'str' } }
+  'data': { 'name': 'str', 'type': 'str', 'description': 'str' } }
 
 ##
 # @device-list-properties:
diff --git a/qdev-monitor.c b/qdev-monitor.c
index 5ec6606..5ee6bf2 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -213,9 +213,14 @@ int qdev_device_help(QemuOpts *opts)
     }
 
     for (prop = prop_list; prop; prop = prop->next) {
-        error_printf("%s.%s=%s\n", driver,
+        error_printf("%s.%s=%s", driver,
                      prop->value->name,
                      prop->value->type);
+        if (prop->value->description) {
+            error_printf(" (%s)\n", prop->value->description);
+        } else {
+            error_printf("\n");
+        }
     }
 
     qapi_free_DevicePropertyInfoList(prop_list);
diff --git a/qmp.c b/qmp.c
index c6767c4..7e17d5a 100644
--- a/qmp.c
+++ b/qmp.c
@@ -442,7 +442,8 @@ ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
  */
 static DevicePropertyInfo *make_device_property_info(ObjectClass *klass,
                                                      const char *name,
-                                                     const char *default_type)
+                                                     const char *default_type,
+                                                     const char *description)
 {
     DevicePropertyInfo *info;
     Property *prop;
@@ -465,7 +466,9 @@ static DevicePropertyInfo 
*make_device_property_info(ObjectClass *klass,
 
             info = g_malloc0(sizeof(*info));
             info->name = g_strdup(prop->name);
-            info->type = g_strdup(prop->info->legacy_name ?: prop->info->name);
+            info->type = g_strdup(prop->info->name);
+            info->description = prop->info->description ?
+                                g_strdup(prop->info->description) : NULL;
             return info;
         }
         klass = object_class_get_parent(klass);
@@ -475,6 +478,8 @@ static DevicePropertyInfo 
*make_device_property_info(ObjectClass *klass,
     info = g_malloc0(sizeof(*info));
     info->name = g_strdup(name);
     info->type = g_strdup(default_type);
+    info->description = description ? g_strdup(description) : NULL;
+
     return info;
 }
 
@@ -521,7 +526,8 @@ DevicePropertyInfoList *qmp_device_list_properties(const 
char *typename,
             continue;
         }
 
-        info = make_device_property_info(klass, prop->name, prop->type);
+        info = make_device_property_info(klass, prop->name, prop->type,
+                                         prop->description);
         if (!info) {
             continue;
         }
-- 
1.7.12.4