vfio/common: Introduce vfio_container_init/destroy helper

This adds two helper functions vfio_container_init/destroy which will be
used by both legacy and iommufd containers to do base container specific
initialization and release.

No functional change intended.

Suggested-by: Cédric Le Goater <clg@redhat.com>
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-base.c

@@ -30,3 +30,12 @@ int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
     g_assert(bcontainer->ops->dma_unmap);
     return bcontainer->ops->dma_unmap(bcontainer, iova, size, iotlb);
 }
+
+void vfio_container_init(VFIOContainerBase *bcontainer, const VFIOIOMMUOps *ops)
+{
+    bcontainer->ops = ops;
+}
+
+void vfio_container_destroy(VFIOContainerBase *bcontainer)
+{
+}

hw/vfio/container.c

@@ -559,7 +559,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     QLIST_INIT(&container->giommu_list);
     QLIST_INIT(&container->vrdl_list);
     bcontainer = &container->bcontainer;
-    bcontainer->ops = &vfio_legacy_ops;
+    vfio_container_init(bcontainer, &vfio_legacy_ops);
 
     ret = vfio_init_container(container, group->fd, errp);
     if (ret) {
@@ -661,6 +661,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
 static void vfio_disconnect_container(VFIOGroup *group)
 {
     VFIOContainer *container = group->container;
+    VFIOContainerBase *bcontainer = &container->bcontainer;
 
     QLIST_REMOVE(group, container_next);
     group->container = NULL;
@@ -695,6 +696,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
             QLIST_REMOVE(giommu, giommu_next);
             g_free(giommu);
         }
+        vfio_container_destroy(bcontainer);
 
         trace_vfio_disconnect_container(container->fd);
         close(container->fd);

include/hw/vfio/vfio-container-base.h

@@ -38,6 +38,10 @@ int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
                              hwaddr iova, ram_addr_t size,
                              IOMMUTLBEntry *iotlb);
 
+void vfio_container_init(VFIOContainerBase *bcontainer,
+                         const VFIOIOMMUOps *ops);
+void vfio_container_destroy(VFIOContainerBase *bcontainer);
+
 struct VFIOIOMMUOps {
     /* basic feature */
     int (*dma_map)(VFIOContainerBase *bcontainer,