vfio/iommufd: Introduce a VFIOIOMMU iommufd QOM interface

As previously done for the sPAPR and legacy IOMMU backends, convert
the VFIOIOMMUOps struct to a QOM interface. The set of of operations
for this backend can be referenced with a literal typename instead of
a C struct.

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>

hw/vfio/common.c

@@ -1508,7 +1508,7 @@ int vfio_attach_device(char *name, VFIODevice *vbasedev,
 
 #ifdef CONFIG_IOMMUFD
     if (vbasedev->iommufd) {
-        ops = &vfio_iommufd_ops;
+        ops = VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD));
     }
 #endif
 

hw/vfio/iommufd.c

@@ -319,6 +319,8 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     int ret, devfd;
     uint32_t ioas_id;
     Error *err = NULL;
+    const VFIOIOMMUClass *iommufd_vioc =
+        VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD));
 
     if (vbasedev->fd < 0) {
         devfd = iommufd_cdev_getfd(vbasedev->sysfsdev, errp);
@@ -340,7 +342,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     /* try to attach to an existing container in this space */
     QLIST_FOREACH(bcontainer, &space->containers, next) {
         container = container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
-        if (bcontainer->ops != &vfio_iommufd_ops ||
+        if (bcontainer->ops != iommufd_vioc ||
             vbasedev->iommufd != container->be) {
             continue;
         }
@@ -374,7 +376,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     container->ioas_id = ioas_id;
 
     bcontainer = &container->bcontainer;
-    vfio_container_init(bcontainer, space, &vfio_iommufd_ops);
+    vfio_container_init(bcontainer, space, iommufd_vioc);
     QLIST_INSERT_HEAD(&space->containers, bcontainer, next);
 
     ret = iommufd_cdev_attach_container(vbasedev, container, errp);
@@ -476,9 +478,11 @@ static void iommufd_cdev_detach(VFIODevice *vbasedev)
 static VFIODevice *iommufd_cdev_pci_find_by_devid(__u32 devid)
 {
     VFIODevice *vbasedev_iter;
+    const VFIOIOMMUClass *iommufd_vioc =
+        VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD));
 
     QLIST_FOREACH(vbasedev_iter, &vfio_device_list, global_next) {
-        if (vbasedev_iter->bcontainer->ops != &vfio_iommufd_ops) {
+        if (vbasedev_iter->bcontainer->ops != iommufd_vioc) {
             continue;
         }
         if (devid == vbasedev_iter->devid) {
@@ -621,10 +625,23 @@ static int iommufd_cdev_pci_hot_reset(VFIODevice *vbasedev, bool single)
     return ret;
 }
 
-const VFIOIOMMUOps vfio_iommufd_ops = {
-    .dma_map = iommufd_cdev_map,
-    .dma_unmap = iommufd_cdev_unmap,
-    .attach_device = iommufd_cdev_attach,
-    .detach_device = iommufd_cdev_detach,
-    .pci_hot_reset = iommufd_cdev_pci_hot_reset,
+static void vfio_iommu_iommufd_class_init(ObjectClass *klass, void *data)
+{
+    VFIOIOMMUClass *vioc = VFIO_IOMMU_CLASS(klass);
+
+    vioc->dma_map = iommufd_cdev_map;
+    vioc->dma_unmap = iommufd_cdev_unmap;
+    vioc->attach_device = iommufd_cdev_attach;
+    vioc->detach_device = iommufd_cdev_detach;
+    vioc->pci_hot_reset = iommufd_cdev_pci_hot_reset;
 };
+
+static const TypeInfo types[] = {
+    {
+        .name = TYPE_VFIO_IOMMU_IOMMUFD,
+        .parent = TYPE_VFIO_IOMMU,
+        .class_init = vfio_iommu_iommufd_class_init,
+    },
+};
+
+DEFINE_TYPES(types)

include/hw/vfio/vfio-common.h

@@ -210,7 +210,6 @@ 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_iommufd_ops;
 extern const MemoryListener vfio_memory_listener;
 extern int vfio_kvm_device_fd;
 

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

@@ -17,7 +17,6 @@
 
 typedef struct VFIODevice VFIODevice;
 typedef struct VFIOIOMMUClass VFIOIOMMUClass;
-#define VFIOIOMMUOps VFIOIOMMUClass /* To remove */
 
 typedef struct {
     unsigned long *bitmap;
@@ -96,6 +95,7 @@ void vfio_container_destroy(VFIOContainerBase *bcontainer);
 #define TYPE_VFIO_IOMMU "vfio-iommu"
 #define TYPE_VFIO_IOMMU_LEGACY TYPE_VFIO_IOMMU "-legacy"
 #define TYPE_VFIO_IOMMU_SPAPR TYPE_VFIO_IOMMU "-spapr"
+#define TYPE_VFIO_IOMMU_IOMMUFD TYPE_VFIO_IOMMU "-iommufd"
 
 /*
  * VFIOContainerBase is not an abstract QOM object because it felt