vsock/virtio: add support for device suspend/resume

Implement .freeze and .restore callbacks of struct virtio_driver
to support device suspend/resume.

During suspension all connected sockets are reset and VQs deleted.
During resume the VQs are re-initialized.

Reported by: Vilas R K <vilas.r.k@intel.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 31f4f6f406147bfc682eb61682ae02ab18688fc1..ad64f403536a9bb41091576d048748da2efbadc7 100644 (file)
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -743,6 +743,49 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
        kfree(vsock);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int virtio_vsock_freeze(struct virtio_device *vdev)
+{
+       struct virtio_vsock *vsock = vdev->priv;
+
+       mutex_lock(&the_virtio_vsock_mutex);
+
+       rcu_assign_pointer(the_virtio_vsock, NULL);
+       synchronize_rcu();
+
+       virtio_vsock_vqs_del(vsock);
+
+       mutex_unlock(&the_virtio_vsock_mutex);
+
+       return 0;
+}
+
+static int virtio_vsock_restore(struct virtio_device *vdev)
+{
+       struct virtio_vsock *vsock = vdev->priv;
+       int ret;
+
+       mutex_lock(&the_virtio_vsock_mutex);
+
+       /* Only one virtio-vsock device per guest is supported */
+       if (rcu_dereference_protected(the_virtio_vsock,
+                               lockdep_is_held(&the_virtio_vsock_mutex))) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       ret = virtio_vsock_vqs_init(vsock);
+       if (ret < 0)
+               goto out;
+
+       rcu_assign_pointer(the_virtio_vsock, vsock);
+
+out:
+       mutex_unlock(&the_virtio_vsock_mutex);
+       return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
 static struct virtio_device_id id_table[] = {
        { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
        { 0 },
@@ -760,6 +803,10 @@ static struct virtio_driver virtio_vsock_driver = {
        .id_table = id_table,
        .probe = virtio_vsock_probe,
        .remove = virtio_vsock_remove,
+#ifdef CONFIG_PM_SLEEP
+       .freeze = virtio_vsock_freeze,
+       .restore = virtio_vsock_restore,
+#endif
 };
 
 static int __init virtio_vsock_init(void)