virtio: reenable config if freezing device failed

[ Upstream commit 310227f42882c52356b523e2f4e11690eebcd2ab ]

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>
Message-Id: <20240213135425.795001-1-david@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 3893dc29eb26338f036379c5664e249ad18f1df6..71dee622b771b3e5e5c9ac0cab286dd052051186 100644 (file)
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -489,13 +489,19 @@ EXPORT_SYMBOL_GPL(unregister_virtio_device);
 int virtio_device_freeze(struct virtio_device *dev)
 {
        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+       int ret;
 
        virtio_config_disable(dev);
 
        dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
 
-       if (drv && drv->freeze)
-               return drv->freeze(dev);
+       if (drv && drv->freeze) {
+               ret = drv->freeze(dev);
+               if (ret) {
+                       virtio_config_enable(dev);
+                       return ret;
+               }
+       }
 
        return 0;
 }