vfio: add vfio_device_prepare()

Commonize some initialization code shared by the legacy and iommufd vfio
implementations.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
Link: https://lore.kernel.org/qemu-devel/20250507152020.1254632-2-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

3 files changed, 17 insertions, 20 deletions

diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index a761f0958b..d30c1a141d 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -826,18 +826,14 @@ static bool vfio_device_get(VFIOGroup *group, const char *name,
         }
     }
 
+    vfio_device_prepare(vbasedev, &group->container->bcontainer, info);
+
     vbasedev->fd = fd;
     vbasedev->group = group;
     QLIST_INSERT_HEAD(&group->device_list, vbasedev, next);
 
-    vbasedev->num_irqs = info->num_irqs;
-    vbasedev->num_regions = info->num_regions;
-    vbasedev->flags = info->flags;
-
     trace_vfio_device_get(name, info->flags, info->num_regions, info->num_irqs);
 
-    vbasedev->reset_works = !!(info->flags & VFIO_DEVICE_FLAGS_RESET);
-
     return true;
 }
 
@@ -890,7 +886,6 @@ static bool vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
     int groupid = vfio_device_get_groupid(vbasedev, errp);
     VFIODevice *vbasedev_iter;
     VFIOGroup *group;
-    VFIOContainerBase *bcontainer;
 
     if (groupid < 0) {
         return false;
@@ -919,11 +914,6 @@ static bool vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
         goto device_put_exit;
     }
 
-    bcontainer = &group->container->bcontainer;
-    vbasedev->bcontainer = bcontainer;
-    QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
-    QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
-
     return true;
 
 device_put_exit:
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index d625a7c4db..f3b9902d21 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -398,3 +398,17 @@ void vfio_device_detach(VFIODevice *vbasedev)
     }
     VFIO_IOMMU_GET_CLASS(vbasedev->bcontainer)->detach_device(vbasedev);
 }
+
+void vfio_device_prepare(VFIODevice *vbasedev, VFIOContainerBase *bcontainer,
+                         struct vfio_device_info *info)
+{
+    vbasedev->num_irqs = info->num_irqs;
+    vbasedev->num_regions = info->num_regions;
+    vbasedev->flags = info->flags;
+    vbasedev->reset_works = !!(info->flags & VFIO_DEVICE_FLAGS_RESET);
+
+    vbasedev->bcontainer = bcontainer;
+    QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
+
+    QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
+}
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 232c06dd15..83033c352a 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -588,14 +588,7 @@ found_container:
         iommufd_cdev_ram_block_discard_disable(false);
     }
 
-    vbasedev->group = 0;
-    vbasedev->num_irqs = dev_info.num_irqs;
-    vbasedev->num_regions = dev_info.num_regions;
-    vbasedev->flags = dev_info.flags;
-    vbasedev->reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
-    vbasedev->bcontainer = bcontainer;
-    QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
-    QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
+    vfio_device_prepare(vbasedev, bcontainer, &dev_info);
 
     trace_iommufd_cdev_device_info(vbasedev->name, devfd, vbasedev->num_irqs,
                                    vbasedev->num_regions, vbasedev->flags);