On 19/05/2023 14:35, Jason Gunthorpe wrote: > On Thu, May 18, 2023 at 09:46:33PM +0100, Joao Martins wrote: > >> @@ -50,6 +54,7 @@ struct iommu_test_cmd { >> __aligned_u64 length; >> } add_reserved; >> struct { >> + __u32 dev_flags; >> __u32 out_stdev_id; >> __u32 out_hwpt_id; > > Don't break the ABI needlessly, syzkaller relies on this IOMMUFD_TEST was quoted "dangerous" in kconfig so I thought that ABI was loosed up I guess I just add a new struct here that extends struct mock_domain inside the union.