vfio/container: Introduce a VFIOIOMMU QOM interface

VFIOContainerBase was not introduced as 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.

Simply transform the VFIOIOMMUOps struct in an InterfaceClass and do
some initial name replacements. Next changes will start converting
VFIOIOMMUOps.

Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index 5c9594b..d6147b4 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -16,7 +16,8 @@
 #include "exec/memory.h"
 
 typedef struct VFIODevice VFIODevice;
-typedef struct VFIOIOMMUOps VFIOIOMMUOps;
+typedef struct VFIOIOMMUClass VFIOIOMMUClass;
+#define VFIOIOMMUOps VFIOIOMMUClass /* To remove */
 
 typedef struct {
     unsigned long *bitmap;
@@ -34,7 +35,7 @@ typedef struct VFIOAddressSpace {
  * This is the base object for vfio container backends
  */
 typedef struct VFIOContainerBase {
-    const VFIOIOMMUOps *ops;
+    const VFIOIOMMUClass *ops;
     VFIOAddressSpace *space;
     MemoryListener listener;
     Error *error;
@@ -88,10 +89,24 @@ int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
 
 void vfio_container_init(VFIOContainerBase *bcontainer,
                          VFIOAddressSpace *space,
-                         const VFIOIOMMUOps *ops);
+                         const VFIOIOMMUClass *ops);
 void vfio_container_destroy(VFIOContainerBase *bcontainer);
 
-struct VFIOIOMMUOps {
+
+#define TYPE_VFIO_IOMMU "vfio-iommu"
+
+/*
+ * 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)
+
+struct VFIOIOMMUClass {
+    InterfaceClass parent_class;
+
     /* basic feature */
     int (*dma_map)(const VFIOContainerBase *bcontainer,
                    hwaddr iova, ram_addr_t size,