[Qemu-devel] [PATCH v3 5/5] virtio: Don't change "started" flag on virtio_vmstate_change()

[elohimes@gmail.com]

From: Xie Yongji <xieyongji@baidu.com>

We will call virtio_set_status() on virtio_vmstate_change().
The "started" flag should not be changed in this case. Otherwise,
we may get an incorrect value when we set "started" flag but
not set DRIVER_OK in source VM.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
---
 hw/virtio/virtio.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index b4301f9e02..9af2e339af 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1163,7 +1163,10 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t val)
         }
     }
 
-    virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK);
+    if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) !=
+        (val & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK);
+    }
 
     if (k->set_status) {
         k->set_status(vdev, val);
-- 
2.17.1