vfio: Introduce base object for VFIOContainer and targeted interface

Introduce a dumb VFIOContainerBase object and its targeted interface.
This is willingly not a QOM object because we don't want it to be
visible from the user interface. The VFIOContainerBase will be
smoothly populated in subsequent patches as well as interfaces.

No functional change intended.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.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>

include/hw/vfio/vfio-common.h

@@ -30,6 +30,7 @@
 #include <linux/vfio.h>
 #endif
 #include "sysemu/sysemu.h"
+#include "hw/vfio/vfio-container-base.h"
 
 #define VFIO_MSG_PREFIX "vfio %s: "
 
@@ -81,6 +82,7 @@ typedef struct VFIOAddressSpace {
 struct VFIOGroup;
 
 typedef struct VFIOContainer {
+    VFIOContainerBase bcontainer;
     VFIOAddressSpace *space;
     int fd; /* /dev/vfio/vfio, empowered by the attached groups */
     MemoryListener listener;
@@ -201,12 +203,6 @@ typedef struct VFIODisplay {
     } dmabuf;
 } VFIODisplay;
 
-typedef struct {
-    unsigned long *bitmap;
-    hwaddr size;
-    hwaddr pages;
-} VFIOBitmap;
-
 VFIOAddressSpace *vfio_get_address_space(AddressSpace *as);
 void vfio_put_address_space(VFIOAddressSpace *space);
 bool vfio_devices_all_running_and_saving(VFIOContainer *container);

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

@@ -0,0 +1,50 @@
+/*
+ * VFIO BASE CONTAINER
+ *
+ * Copyright (C) 2023 Intel Corporation.
+ * Copyright Red Hat, Inc. 2023
+ *
+ * Authors: Yi Liu <yi.l.liu@intel.com>
+ *          Eric Auger <eric.auger@redhat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_VFIO_VFIO_CONTAINER_BASE_H
+#define HW_VFIO_VFIO_CONTAINER_BASE_H
+
+#include "exec/memory.h"
+
+typedef struct VFIODevice VFIODevice;
+typedef struct VFIOIOMMUOps VFIOIOMMUOps;
+
+typedef struct {
+    unsigned long *bitmap;
+    hwaddr size;
+    hwaddr pages;
+} VFIOBitmap;
+
+/*
+ * This is the base object for vfio container backends
+ */
+typedef struct VFIOContainerBase {
+    const VFIOIOMMUOps *ops;
+} VFIOContainerBase;
+
+struct VFIOIOMMUOps {
+    /* basic feature */
+    int (*dma_map)(VFIOContainerBase *bcontainer,
+                   hwaddr iova, ram_addr_t size,
+                   void *vaddr, bool readonly);
+    int (*dma_unmap)(VFIOContainerBase *bcontainer,
+                     hwaddr iova, ram_addr_t size,
+                     IOMMUTLBEntry *iotlb);
+    int (*attach_device)(const char *name, VFIODevice *vbasedev,
+                         AddressSpace *as, Error **errp);
+    void (*detach_device)(VFIODevice *vbasedev);
+    /* migration feature */
+    int (*set_dirty_page_tracking)(VFIOContainerBase *bcontainer, bool start);
+    int (*query_dirty_bitmap)(VFIOContainerBase *bcontainer, VFIOBitmap *vbmap,
+                              hwaddr iova, hwaddr size);
+};
+#endif /* HW_VFIO_VFIO_CONTAINER_BASE_H */