[Qemu-devel] [v1 Patch 1/10]Qemu: Enhance "info block" to display host cache setting

[Supriya Kannery <supriyak@linux.vnet.ibm.com>]

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

Example:
(qemu) info block
ide0-hd0: removable=0 file=../rhel6-32.raw ro=0 drv=raw encrypted=0

Enhanced to display "hostcache" setting:
(qemu) info block
ide0-hd0: removable=0 hostcache=1 file=../rhel6-32.raw ro=0 drv=raw encrypted=0

Signed-off-by: Supriya Kannery <supriyak@linux.vnet.ibm.com>

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

Index: qemu/qapi-schema.json
===================================================================
--- qemu.orig/qapi-schema.json
+++ qemu/qapi-schema.json
@@ -447,6 +447,8 @@
 # @locked: True if the guest has locked this device from having its media
 #          removed
 #
+# @hostcache: True if host pagecache is enabled.
+#
 # @tray_open: #optional True if the device has a tray and it is open
 #             (only present if removable is true)
 #
@@ -460,7 +462,7 @@
 ##
 { 'type': 'BlockInfo',
   'data': {'device': 'str', 'type': 'str', 'removable': 'bool',
-           'locked': 'bool', '*inserted': 'BlockDeviceInfo',
+           'locked': 'bool','hostcache': 'bool', '*inserted': 'BlockDeviceInfo',
            '*tray_open': 'bool', '*io-status': 'BlockDeviceIoStatus'} }
 
 ##
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c
+++ qemu/block.c
@@ -2581,6 +2581,7 @@ BlockInfoList *qmp_query_block(Error **e
         info->value->device = g_strdup(bs->device_name);
         info->value->type = g_strdup("unknown");
         info->value->locked = bdrv_dev_is_medium_locked(bs);
+        info->value->hostcache = !(bs->open_flags & BDRV_O_NOCACHE);
         info->value->removable = bdrv_dev_has_removable_media(bs);
 
         if (bdrv_dev_has_removable_media(bs)) {
Index: qemu/hmp.c
===================================================================
--- qemu.orig/hmp.c
+++ qemu/hmp.c
@@ -212,6 +212,8 @@ void hmp_info_block(Monitor *mon)
             monitor_printf(mon, " tray-open=%d", info->value->tray_open);
         }
 
+        monitor_printf(mon, " hostcache=%d", info->value->hostcache);
+
         if (info->value->has_io_status) {
             monitor_printf(mon, " io-status=%s",
                            BlockDeviceIoStatus_lookup[info->value->io_status]);