cryptodev: introduce a new is_used property

This property is used to Tag the cryptodev backend
is used by virtio-crypto or not. Making cryptodev
can't be hot unplugged when it's in use. Cleanup
resources when cryptodev is finalized.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/include/sysemu/cryptodev.h b/include/sysemu/cryptodev.h
index 84526c0..461389d 100644
--- a/include/sysemu/cryptodev.h
+++ b/include/sysemu/cryptodev.h
@@ -202,6 +202,8 @@
     Object parent_obj;
 
     bool ready;
+    /* Tag the cryptodev backend is used by virtio-crypto or not */
+    bool is_used;
     CryptoDevBackendConf conf;
 };
 
@@ -295,4 +297,25 @@
                  void *opaque,
                  uint32_t queue_index, Error **errp);
 
+/**
+ * cryptodev_backend_set_used:
+ * @backend: the cryptodev backend object
+ * @used: ture or false
+ *
+ * Set the cryptodev backend is used by virtio-crypto or not
+ */
+void cryptodev_backend_set_used(CryptoDevBackend *backend, bool used);
+
+/**
+ * cryptodev_backend_is_used:
+ * @backend: the cryptodev backend object
+ *
+ * Return the status that the cryptodev backend is used
+ * by virtio-crypto or not
+ *
+ * Returns: true on used, or false on not used
+ */
+bool cryptodev_backend_is_used(CryptoDevBackend *backend);
+
+
 #endif /* CRYPTODEV_H */