Currently, we don't reenable the config if freezing the device failed.

For example, virtio-mem currently doesn't support suspend+resume, and
trying to freeze the device will always fail. Afterwards, the device
will no longer respond to resize requests, because it won't get notified
about config changes.

Let's fix this by re-enabling the config if freezing fails.

Fixes: 22b7050a024d ("virtio: defer config changed notifications")
Cc: <stable@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/virtio/virtio.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index f4080692b351..f513ee21b1c1 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -510,8 +510,10 @@ int virtio_device_freeze(struct virtio_device *dev)
 
 	if (drv && drv->freeze) {
 		ret = drv->freeze(dev);
-		if (ret)
+		if (ret) {
+			virtio_config_enable(dev);
 			return ret;
+		}
 	}
 
 	if (dev->config->destroy_avq)

base-commit: c664e16bb1ba1c8cf1d7ecf3df5fd83bbb8ac15a
-- 
2.43.0