vfio/container: Introduce a empty VFIOIOMMUOps

This empty VFIOIOMMUOps named vfio_legacy_ops will hold all general
IOMMU ops of legacy container.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/container.c

@@ -472,6 +472,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
                                   Error **errp)
 {
     VFIOContainer *container;
+    VFIOContainerBase *bcontainer;
     int ret, fd;
     VFIOAddressSpace *space;
 
@@ -552,6 +553,8 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     container->iova_ranges = NULL;
     QLIST_INIT(&container->giommu_list);
     QLIST_INIT(&container->vrdl_list);
+    bcontainer = &container->bcontainer;
+    bcontainer->ops = &vfio_legacy_ops;
 
     ret = vfio_init_container(container, group->fd, errp);
     if (ret) {
@@ -933,3 +936,5 @@ void vfio_detach_device(VFIODevice *vbasedev)
     vfio_put_base_device(vbasedev);
     vfio_put_group(group);
 }
+
+const VFIOIOMMUOps vfio_legacy_ops;

include/hw/vfio/vfio-common.h

@@ -255,7 +255,7 @@ typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList;
 typedef QLIST_HEAD(VFIODeviceList, VFIODevice) VFIODeviceList;
 extern VFIOGroupList vfio_group_list;
 extern VFIODeviceList vfio_device_list;
-
+extern const VFIOIOMMUOps vfio_legacy_ops;
 extern const MemoryListener vfio_memory_listener;
 extern int vfio_kvm_device_fd;