[Qemu-devel] [PATCH] Disable virtio-balloon memory stats interface

[Adam Litke <agl@us.ibm.com>]

The addition of memory stats reporting to the virtio balloon causes
the 'info balloon' command to become asynchronous.  This is a regression
because in some cases it can hang the user monitor.

Disable this feature until a better interface for asynchronous commands
can be worked out.

Signed-off-by: Adam Litke <agl@us.ibm.com>
---
 hw/virtio-balloon.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c
index 9fe3886..dcdada6 100644
--- a/hw/virtio-balloon.c
+++ b/hw/virtio-balloon.c
@@ -190,7 +190,17 @@ static void virtio_balloon_set_config(VirtIODevice *vdev,
 
 static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
 {
-    f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
+    /*
+     * The addition of memory stats reporting to the virtio balloon causes
+     * the 'info balloon' command to become asynchronous.  This is a regression
+     * because in some cases it can hang the user monitor.
+     *
+     * Disable this feature until a better interface for asynchronous commands
+     * can be worked out.
+     *
+     * -aglitke
+     */
+    /* f |= (1 << VIRTIO_BALLOON_F_STATS_VQ); */
     return f;
 }
 
-- 
1.6.1.3