Let's turn attach/detach_device as container callbacks. That way,
their implementation can be easily customized for a given backend.

For the time being, only the legacy container is supported.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 include/hw/vfio/vfio-common.h         |  1 +
 include/hw/vfio/vfio-container-base.h |  2 ++
 hw/vfio/as.c                          | 21 +++++++++++++++++++++
 hw/vfio/container.c                   |  9 +++++++--
 hw/vfio/pci.c                         |  2 +-
 5 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 1580f9617c..4f89657ac1 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -86,6 +86,7 @@ typedef struct VFIODeviceOps VFIODeviceOps;
 typedef struct VFIODevice {
     QLIST_ENTRY(VFIODevice) next;
     struct VFIOGroup *group;
+    VFIOContainer *container;
     char *sysfsdev;
     char *name;
     DeviceState *dev;
diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index 6080a588bf..5e47faf293 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -133,6 +133,8 @@ struct VFIOIOMMUBackendOpsClass {
     int (*dma_unmap)(VFIOContainer *container,
                      hwaddr iova, ram_addr_t size,
                      IOMMUTLBEntry *iotlb);
+    int (*attach_device)(VFIODevice *vbasedev, AddressSpace *as, Error **errp);
+    void (*detach_device)(VFIODevice *vbasedev);
     /* migration feature */
     bool (*devices_all_dirty_tracking)(VFIOContainer *container);
     void (*set_dirty_page_tracking)(VFIOContainer *container, bool start);
diff --git a/hw/vfio/as.c b/hw/vfio/as.c
index 6a5f3f80b5..d212974b9b 100644
--- a/hw/vfio/as.c
+++ b/hw/vfio/as.c
@@ -851,6 +851,27 @@ void vfio_put_address_space(VFIOAddressSpace *space)
     }
 }
 
+int vfio_attach_device(VFIODevice *vbasedev, AddressSpace *as, Error **errp)
+{
+    const VFIOIOMMUBackendOpsClass *ops;
+
+    ops = VFIO_IOMMU_BACKEND_OPS_CLASS(
+                  object_class_by_name(TYPE_VFIO_IOMMU_BACKEND_LEGACY_OPS));
+    if (!ops) {
+        error_setg(errp, "VFIO IOMMU Backend not found!");
+        return -ENODEV;
+    }
+    return ops->attach_device(vbasedev, as, errp);
+}
+
+void vfio_detach_device(VFIODevice *vbasedev)
+{
+    if (!vbasedev->container) {
+        return;
+    }
+    vbasedev->container->ops->detach_device(vbasedev);
+}
+
 static const TypeInfo vfio_iommu_backend_ops_type_info = {
     .name = TYPE_VFIO_IOMMU_BACKEND_OPS,
     .parent = TYPE_OBJECT,
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index b9ee56067c..e99d12f4d8 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -1278,7 +1278,8 @@ static int vfio_device_groupid(VFIODevice *vbasedev, Error **errp)
     return groupid;
 }
 
-int vfio_attach_device(VFIODevice *vbasedev, AddressSpace *as, Error **errp)
+static int
+vfio_legacy_attach_device(VFIODevice *vbasedev, AddressSpace *as, Error **errp)
 {
     int groupid = vfio_device_groupid(vbasedev, errp);
     VFIODevice *vbasedev_iter;
@@ -1307,14 +1308,16 @@ int vfio_attach_device(VFIODevice *vbasedev, AddressSpace *as, Error **errp)
         vfio_put_group(group);
         return -1;
     }
+    vbasedev->container = &group->container->bcontainer;
 
     return 0;
 }
 
-void vfio_detach_device(VFIODevice *vbasedev)
+static void vfio_legacy_detach_device(VFIODevice *vbasedev)
 {
     vfio_put_base_device(vbasedev);
     vfio_put_group(vbasedev->group);
+    vbasedev->container = NULL;
 }
 
 static void vfio_iommu_backend_legacy_ops_class_init(ObjectClass *oc,
@@ -1329,6 +1332,8 @@ static void vfio_iommu_backend_legacy_ops_class_init(ObjectClass *oc,
     ops->add_window = vfio_legacy_container_add_section_window;
     ops->del_window = vfio_legacy_container_del_section_window;
     ops->check_extension = vfio_legacy_container_check_extension;
+    ops->attach_device = vfio_legacy_attach_device;
+    ops->detach_device = vfio_legacy_detach_device;
 }
 
 static const TypeInfo vfio_iommu_backend_legacy_ops_type = {
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 9856d81819..07361a6fcd 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3106,7 +3106,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     }
 
     if (!pdev->failover_pair_id &&
-        vfio_container_check_extension(&vbasedev->group->container->bcontainer,
+        vfio_container_check_extension(vbasedev->container,
                                        VFIO_FEAT_LIVE_MIGRATION)) {
         ret = vfio_migration_probe(vbasedev, errp);
         if (ret) {
-- 
2.37.3