On Wed, Sep 22, 2021 at 03:01:01PM -0600, Alex Williamson wrote: > On Tue, 21 Sep 2021 14:29:39 -0300 > Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > > > On Sun, Sep 19, 2021 at 02:38:36PM +0800, Liu Yi L wrote: > > > +struct vfio_device_iommu_bind_data { > > > + __u32 argsz; > > > + __u32 flags; > > > + __s32 iommu_fd; > > > + __u64 dev_cookie; > > > > Missing explicit padding > > > > Always use __aligned_u64 in uapi headers, fix all the patches. > > We don't need padding or explicit alignment if we just swap the order > of iommu_fd and dev_cookie. Thanks, Yes, the padding should all be checked and minimized But it is always good practice to always use __aligned_u64 in the uapi headers just in case someone messes it up someday - it prevents small mistakes from becoming an ABI mess. Jason