On Mon, 18 Sep 2023 16:56:14 -0400 Stefan Hajnoczi <stefanha@xxxxxxxxxx> wrote: > v3: > - Remove the output struct sizing code that copied out zeroed fields at the end > of the struct. Alex pointed out that new fields (or repurposing a field that > was previously reserved) must be guarded by a flag and this means userspace > won't access those fields when they are absent. > v2: > - Rebased onto https://github.com/awilliam/linux-vfio.git next to get the > vfio_iommu_type1_info pad field [Kevin] > - Fixed min(minsz, sizeof(dmabuf)) -> min(dmabuf.argsz, sizeof(dmabuf)) [Jason, Kevin] > - Squashed Patch 3 (vfio_iommu_type1_info) into Patch 1 since it is trivial now > that the padding field is already there. > > Jason Gunthorpe <jgg@xxxxxxxxxx> pointed out that u64 VFIO ioctl struct fields > have architecture-dependent alignment. iommufd already uses __aligned_u64 to > avoid this problem. > > See the __aligned_u64 typedef in <uapi/linux/types.h> for details on why it is > a good idea for kernel<->user interfaces. > > This series modifies the VFIO ioctl structs to use __aligned_u64. Some of the > changes preserve the existing memory layout on all architectures, so I put them > together into the first patch. The remaining patches are for structs where > explanation is necessary about why changing the memory layout does not break > the uapi. > > Stefan Hajnoczi (3): > vfio: trivially use __aligned_u64 for ioctl structs > vfio: use __aligned_u64 in struct vfio_device_gfx_plane_info > vfio: use __aligned_u64 in struct vfio_device_ioeventfd > > include/uapi/linux/vfio.h | 26 ++++++++++++++------------ > drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +- > samples/vfio-mdev/mbochs.c | 2 +- > samples/vfio-mdev/mdpy.c | 2 +- > 4 files changed, 17 insertions(+), 15 deletions(-) > Applied to vfio next branch for v6.7. Thanks, Alex
