diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
index 280f0dd..98c15e1 100644
--- a/hw/vfio/container-base.c
+++ b/hw/vfio/container-base.c
@@ -102,8 +102,10 @@
 static const TypeInfo types[] = {
     {
         .name = TYPE_VFIO_IOMMU,
-        .parent = TYPE_INTERFACE,
+        .parent = TYPE_OBJECT,
+        .instance_size = sizeof(VFIOContainerBase),
         .class_size = sizeof(VFIOIOMMUClass),
+        .abstract = true,
     },
 };
 
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 31bdc46..3ae5253 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -1196,6 +1196,7 @@
     {
         .name = TYPE_VFIO_IOMMU_LEGACY,
         .parent = TYPE_VFIO_IOMMU,
+        .instance_size = sizeof(VFIOContainer),
         .class_init = vfio_iommu_legacy_class_init,
     }, {
         .name = TYPE_HOST_IOMMU_DEVICE_LEGACY_VFIO,
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index e5d9334..3e9d642 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -672,6 +672,7 @@
     {
         .name = TYPE_VFIO_IOMMU_IOMMUFD,
         .parent = TYPE_VFIO_IOMMU,
+        .instance_size = sizeof(VFIOIOMMUFDContainer),
         .class_init = vfio_iommu_iommufd_class_init,
     }, {
         .name = TYPE_HOST_IOMMU_DEVICE_IOMMUFD_VFIO,
diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c
index 47b040f..018bd20 100644
--- a/hw/vfio/spapr.c
+++ b/hw/vfio/spapr.c
@@ -30,6 +30,8 @@
     QLIST_HEAD(, VFIOHostDMAWindow) hostwin_list;
 } VFIOSpaprContainer;
 
+OBJECT_DECLARE_SIMPLE_TYPE(VFIOSpaprContainer, VFIO_IOMMU_SPAPR);
+
 static bool vfio_prereg_listener_skipped_section(MemoryRegionSection *section)
 {
     if (memory_region_is_iommu(section->mr)) {
@@ -548,6 +550,7 @@
     {
         .name = TYPE_VFIO_IOMMU_SPAPR,
         .parent = TYPE_VFIO_IOMMU_LEGACY,
+        .instance_size = sizeof(VFIOSpaprContainer),
         .class_init = vfio_iommu_spapr_class_init,
     },
 };
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 825d801..e8ddf92 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -84,6 +84,8 @@
     QLIST_HEAD(, VFIOGroup) group_list;
 } VFIOContainer;
 
+OBJECT_DECLARE_SIMPLE_TYPE(VFIOContainer, VFIO_IOMMU_LEGACY);
+
 typedef struct VFIOHostDMAWindow {
     hwaddr min_iova;
     hwaddr max_iova;
@@ -99,6 +101,8 @@
     uint32_t ioas_id;
 } VFIOIOMMUFDContainer;
 
+OBJECT_DECLARE_SIMPLE_TYPE(VFIOIOMMUFDContainer, VFIO_IOMMU_IOMMUFD);
+
 typedef struct VFIODeviceOps VFIODeviceOps;
 
 typedef struct VFIODevice {
diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index d505f63..b079b76f 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -34,6 +34,7 @@
  * This is the base object for vfio container backends
  */
 typedef struct VFIOContainerBase {
+    Object parent;
     const VFIOIOMMUClass *ops;
     VFIOAddressSpace *space;
     MemoryListener listener;
@@ -96,17 +97,10 @@
 #define TYPE_VFIO_IOMMU_SPAPR TYPE_VFIO_IOMMU "-spapr"
 #define TYPE_VFIO_IOMMU_IOMMUFD TYPE_VFIO_IOMMU "-iommufd"
 
-/*
- * VFIOContainerBase is not an abstract QOM object because it felt
- * unnecessary to expose all the IOMMU backends to the QEMU machine
- * and human interface. However, we can still abstract the IOMMU
- * backend handlers using a QOM interface class. This provides more
- * flexibility when referencing the various implementations.
- */
-DECLARE_CLASS_CHECKERS(VFIOIOMMUClass, VFIO_IOMMU, TYPE_VFIO_IOMMU)
+OBJECT_DECLARE_TYPE(VFIOContainerBase, VFIOIOMMUClass, VFIO_IOMMU)
 
 struct VFIOIOMMUClass {
-    InterfaceClass parent_class;
+    ObjectClass parent_class;
 
     /* Properties */
     const char *hiod_typename;