1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 6e47a3df1a71..4f82a6fa7c6c 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -98,3 +98,61 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);
+
+/*
+ * The emulated standard ops mean that vfio_device is going to use the
+ * "mdev path" and will call vfio_pin_pages()/vfio_dma_rw(). Drivers using this
+ * ops set should call vfio_register_emulated_iommu_dev().
+ */
+
+static void vfio_emulated_unmap(void *data, unsigned long iova,
+				unsigned long length)
+{
+	struct vfio_device *vdev = data;
+
+	vdev->ops->dma_unmap(vdev, iova, length);
+}
+
+static const struct iommufd_access_ops vfio_user_ops = {
+	.needs_pin_pages = 1,
+	.unmap = vfio_emulated_unmap,
+};
+
+int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
+			       struct iommufd_ctx *ictx, u32 *out_device_id)
+{
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	vdev->iommufd_ictx = ictx;
+	iommufd_ctx_get(ictx);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_bind);
+
+void vfio_iommufd_emulated_unbind(struct vfio_device *vdev)
+{
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	if (vdev->iommufd_access) {
+		iommufd_access_destroy(vdev->iommufd_access);
+		vdev->iommufd_access = NULL;
+	}
+	iommufd_ctx_put(vdev->iommufd_ictx);
+	vdev->iommufd_ictx = NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_unbind);
+
+int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
+{
+	struct iommufd_access *user;
+
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	user = iommufd_access_create(vdev->iommufd_ictx, *pt_id, &vfio_user_ops,
+				     vdev);
+	if (IS_ERR(user))
+		return PTR_ERR(user);
+	vdev->iommufd_access = user;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas);