Re: [Qemu-devel] [V5 Patch 1/4]Qemu: Enhance "info block" to display host cache setting

[Supriya Kannery]

On 07/27/2011 07:49 PM, Stefan Hajnoczi wrote:
On Wed, Jul 27, 2011 at 12:30 PM, Supriya Kannery
<supri...@linux.vnet.ibm.com>  wrote:
Enhance "info block" to display hostcache setting for each
block device.
Example:
(qemu) info block
ide0-hd0: type=hd removable=0 file=../rhel6-32.qcow2 ro=0 drv=qcow2
encrypted=0

Enhanced to display "hostcache" setting:
(qemu) info block
ide0-hd0: type=hd removable=0 hostcache=true file=../rhel6-32.qcow2
ro=0 drv=qcow2 encrypted=0

This description is outdated, should be hostcache=1 instead of hostcache=true.

@@ -1749,13 +1757,18 @@ void bdrv_info(Monitor *mon, QObject **r
         QObject *bs_obj;

         bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': 'unknown', "
-                                    "'removable': %i, 'locked': %i }",
-                                    bs->device_name, bs->removable,
-                                    bs->locked);
+                                     "'removable': %i, 'locked': %i, "
+                                     "'hostcache': %s }",
+                                     bs->device_name, bs->removable,
+                                     bs->locked,
+                                     (bs->open_flags&  BDRV_O_NOCACHE) ?
+                                     "false" : "true");

Please use the same bool-from-int format specifier ('%i') as the other
fields for consistency.  The value can be !(bs->open_flags&
BDRV_O_NOCACHE).


ok

+
+        QDict *bs_dict = qobject_to_qdict(bs_obj);
+        qdict_put(bs_dict, "open_flags", qint_from_int(bs->open_flags));

         if (bs->drv) {
             QObject *obj;
-            QDict *bs_dict = qobject_to_qdict(bs_obj);

             obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
                                      "'encrypted': %i }",

My copy of the code has the following a few lines further down:
qdict_put_obj(bs_dict, "inserted", obj);

Removing bs_dict would break the build.  Am I missing something?


qdict_put_obj() for "inserted" is still there further down in the code.
Here,
  QDict *bs_dict = qobject_to_qdict(bs_obj);
is moved up to enable placing of "open_flags" into the dict. We need 
"open_flags" in dict to calculate hostcache value for printing in
monitor. Code for placing "inserted" is not touched.

Index: qemu/qmp-commands.hx
===================================================================
--- qemu.orig/qmp-commands.hx
+++ qemu/qmp-commands.hx
@@ -1131,6 +1131,7 @@ Each json-object contain the following:
          - Possible values: "unknown"
  - "removable": true if the device is removable, false otherwise (json-bool)
  - "locked": true if the device is locked, false otherwise (json-bool)
+- "hostcache": true if hostcache enabled, false otherwise (json-bool)

Let's explain what "hostcache" means:

- "hostcache": true if host page cache is enabled, false otherwise (json-bool)


ok

-Thanks, Supriya

Stefan