[Qemu-devel] [v8 Patch 1/6]Qemu: Enhance "info block" to display host cache setting

[Supriya Kannery]

Enhance "info block" to display hostcache setting for each
block device.

Example:
(qemu) info block
ide0-hd0: removable=0 file=../sles11-32.raw ro=0 drv=raw encrypted=0

Enhanced to display "hostcache" setting:
(qemu) info block
ide0-hd0: removable=0 hostcache=1 file=../sles11-32.raw ro=0 drv=raw encrypted=0

Signed-off-by: Supriya Kannery <address@hidden>

---
 block.c         |   20 ++++++++++++++++----
 qmp-commands.hx |    2 ++
 2 files changed, 18 insertions(+), 4 deletions(-)

Index: qemu/qmp-commands.hx
===================================================================
--- qemu.orig/qmp-commands.hx
+++ qemu/qmp-commands.hx
@@ -1142,6 +1142,7 @@ Each json-object contain the following:
 - "locked": true if the device is locked, false otherwise (json-bool)
 - "tray-open": only present if removable, true if the device has a tray,
                and it is open (json-bool)
+- "hostcache": true if host pagecache enabled, false otherwise (json-bool)
 - "inserted": only present if the device is inserted, it is a json-object
    containing the following:
          - "file": device file name (json-string)
@@ -1168,6 +1169,7 @@ Example:
             "io-status": "ok",
             "device":"ide0-hd0",
             "locked":false,
+            "hostcache":false,
             "removable":false,
             "inserted":{
                "ro":false,
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c
+++ qemu/block.c
@@ -1841,6 +1841,11 @@ static void bdrv_print_dict(QObject *obj
                        qdict_get_bool(bs_dict, "tray-open"));
     }
 
+    if (qdict_haskey(bs_dict, "hostcache")) {
+        monitor_printf(mon, " hostcache=%d",
+                       qdict_get_bool(bs_dict, "hostcache"));
+    }
+
     if (qdict_haskey(bs_dict, "io-status")) {
         monitor_printf(mon, " io-status=%s", qdict_get_str(bs_dict, 
"io-status"));
     }
@@ -1888,10 +1893,12 @@ void bdrv_info(Monitor *mon, QObject **r
         QDict *bs_dict;
 
         bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': 'unknown', "
-                                    "'removable': %i, 'locked': %i }",
+                                    "'removable': %i, 'locked': %i, "
+                                    "'hostcache': %i }",
                                     bs->device_name,
                                     bdrv_dev_has_removable_media(bs),
-                                    bdrv_dev_is_medium_locked(bs));
+                                    bdrv_dev_is_medium_locked(bs),
+                                    !(bs->open_flags & BDRV_O_NOCACHE));
         bs_dict = qobject_to_qdict(bs_obj);
 
         if (bdrv_dev_has_removable_media(bs)) {