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: NGonglei <arei.gonglei@huawei.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

backends/cryptodev.c

@@ -197,6 +197,22 @@ out:
     error_propagate(errp, local_err);
 }
 
+void cryptodev_backend_set_used(CryptoDevBackend *backend, bool used)
+{
+    backend->is_used = used;
+}
+
+bool cryptodev_backend_is_used(CryptoDevBackend *backend)
+{
+    return backend->is_used;
+}
+
+static bool
+cryptodev_backend_can_be_deleted(UserCreatable *uc, Error **errp)
+{
+    return !cryptodev_backend_is_used(CRYPTODEV_BACKEND(uc));
+}
+
 static void cryptodev_backend_instance_init(Object *obj)
 {
     object_property_add(obj, "queues", "int",
@@ -209,7 +225,9 @@ static void cryptodev_backend_instance_init(Object *obj)
 
 static void cryptodev_backend_finalize(Object *obj)
 {
+    CryptoDevBackend *backend = CRYPTODEV_BACKEND(obj);
 
+    cryptodev_backend_cleanup(backend, NULL);
 }
 
 static void
@@ -218,6 +236,7 @@ cryptodev_backend_class_init(ObjectClass *oc, void *data)
     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 
     ucc->complete = cryptodev_backend_complete;
+    ucc->can_be_deleted = cryptodev_backend_can_be_deleted;
 
     QTAILQ_INIT(&crypto_clients);
 }

hw/virtio/virtio-crypto.c

@@ -799,6 +799,7 @@ static void virtio_crypto_device_realize(DeviceState *dev, Error **errp)
     }
 
     virtio_crypto_init_config(vdev);
+    cryptodev_backend_set_used(vcrypto->cryptodev, true);
 }
 
 static void virtio_crypto_device_unrealize(DeviceState *dev, Error **errp)
@@ -818,6 +819,7 @@ static void virtio_crypto_device_unrealize(DeviceState *dev, Error **errp)
     g_free(vcrypto->vqs);
 
     virtio_cleanup(vdev);
+    cryptodev_backend_set_used(vcrypto->cryptodev, false);
 }
 
 static const VMStateDescription vmstate_virtio_crypto = {

include/sysemu/cryptodev.h

@@ -202,6 +202,8 @@ struct CryptoDevBackend {
     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 @@ int cryptodev_backend_crypto_operation(
                  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 */