vfio: Create host IOMMU device instance

Create host IOMMU device instance in vfio_attach_device() and call
.realize() to initialize it further.

Introuduce attribute VFIOIOMMUClass::hiod_typename and initialize
it based on VFIO backend type. It will facilitate HostIOMMUDevice
creation in vfio_attach_device().

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

hw/vfio/common.c

@@ -1528,6 +1528,7 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev,
 {
     const VFIOIOMMUClass *ops =
         VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY));
+    HostIOMMUDevice *hiod;
 
     if (vbasedev->iommufd) {
         ops = VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD));
@@ -1535,7 +1536,19 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev,
 
     assert(ops);
 
-    return ops->attach_device(name, vbasedev, as, errp);
+    if (!ops->attach_device(name, vbasedev, as, errp)) {
+        return false;
+    }
+
+    hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename));
+    if (!HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev, errp)) {
+        object_unref(hiod);
+        ops->detach_device(vbasedev);
+        return false;
+    }
+    vbasedev->hiod = hiod;
+
+    return true;
 }
 
 void vfio_detach_device(VFIODevice *vbasedev)
@@ -1543,5 +1556,6 @@ void vfio_detach_device(VFIODevice *vbasedev)
     if (!vbasedev->bcontainer) {
         return;
     }
+    object_unref(vbasedev->hiod);
     vbasedev->bcontainer->ops->detach_device(vbasedev);
 }

hw/vfio/container.c

@@ -1126,6 +1126,8 @@ static void vfio_iommu_legacy_class_init(ObjectClass *klass, void *data)
 {
     VFIOIOMMUClass *vioc = VFIO_IOMMU_CLASS(klass);
 
+    vioc->hiod_typename = TYPE_HOST_IOMMU_DEVICE_LEGACY_VFIO;
+
     vioc->setup = vfio_legacy_setup;
     vioc->dma_map = vfio_legacy_dma_map;
     vioc->dma_unmap = vfio_legacy_dma_unmap;

hw/vfio/iommufd.c

@@ -612,6 +612,8 @@ static void vfio_iommu_iommufd_class_init(ObjectClass *klass, void *data)
 {
     VFIOIOMMUClass *vioc = VFIO_IOMMU_CLASS(klass);
 
+    vioc->hiod_typename = TYPE_HOST_IOMMU_DEVICE_IOMMUFD_VFIO;
+
     vioc->dma_map = iommufd_cdev_map;
     vioc->dma_unmap = iommufd_cdev_unmap;
     vioc->attach_device = iommufd_cdev_attach;

include/hw/vfio/vfio-common.h

@@ -127,6 +127,7 @@ typedef struct VFIODevice {
     OnOffAuto pre_copy_dirty_page_tracking;
     bool dirty_pages_supported;
     bool dirty_tracking;
+    HostIOMMUDevice *hiod;
     int devid;
     IOMMUFDBackend *iommufd;
 } VFIODevice;

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

@@ -109,6 +109,9 @@ DECLARE_CLASS_CHECKERS(VFIOIOMMUClass, VFIO_IOMMU, TYPE_VFIO_IOMMU)
 struct VFIOIOMMUClass {
     InterfaceClass parent_class;
 
+    /* Properties */
+    const char *hiod_typename;
+
     /* basic feature */
     bool (*setup)(VFIOContainerBase *bcontainer, Error **errp);
     int (*dma_map)(const VFIOContainerBase *bcontainer,