[Stable-8.2.9 32/45] vhost-user: fix shared object return values

[Michael Tokarev]

VHOST_USER_BACKEND_SHARED_OBJECT_ADD and
VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE state
in the spec that they return 0 for successful
operations, non-zero otherwise. However,
implementation relies on the return types
of the virtio-dmabuf library, with opposite
semantics (true if everything is correct,
false otherwise). Therefore, current
implementation violates the specification.

Revert the logic so that the implementation
of the vhost-user handling methods matches
the specification.

Fixes: 043e127a126bb3ceb5fc753deee27d261fd0c5ce
Fixes: 160947666276c5b7f6bca4d746bcac2966635d79
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
Message-Id: <20241022124615.585596-1-aesteve@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit eea5aeef84e1b74f515b474d3a86377701f93750)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(Mjt: remove changes fixing v8.2.0-2279-g043e127a126b
 "hw/virtio: check owner for removing objects")

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index f214df804b..7db7981841 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1607,16 +1607,21 @@ vhost_user_backend_handle_shared_object_add(struct 
vhost_dev *dev,
     QemuUUID uuid;
 
     memcpy(uuid.data, object->uuid, sizeof(object->uuid));
-    return virtio_add_vhost_device(&uuid, dev);
+    return !virtio_add_vhost_device(&uuid, dev);
 }
 
+/*
+ * Handle VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE backend requests.
+ *
+ * Return: 0 on success, 1 on error.
+ */
 static int
 vhost_user_backend_handle_shared_object_remove(VhostUserShared *object)
 {
     QemuUUID uuid;
 
     memcpy(uuid.data, object->uuid, sizeof(object->uuid));
-    return virtio_remove_resource(&uuid);
+    return !virtio_remove_resource(&uuid);
 }
 
 static bool vhost_user_send_resp(QIOChannel *ioc, VhostUserHeader *hdr,
-- 
2.39.5