Re: [PATCH v2] vfio: selftests: only build tests on arm64 and x86_64

[Jason Gunthorpe <jgg@nvidia.com>]

On Tue, Mar 17, 2026 at 01:55:17PM +0000, Matt Evans wrote:
> Hi Ted,
> 
> On 03/02/2026 01:23, Ted Logan wrote:
> > Only build vfio self-tests on arm64 and x86_64; these are the only
> > architectures where the vfio self-tests are run. Addresses compiler
> > warnings for format and conversions on i386.
> > 
> > Reported-by: kernel test robot <lkp@intel.com>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202601211830.aBEjmEFD-lkp@intel.com/
> > Signed-off-by: Ted Logan <tedlogan@fb.com>
> > ---
> > Do not build vfio self-tests for 32-bit architectures, where they're
> > untested and unmaintained. Only build these tests for arm64 and x86_64,
> > where they're regularly tested.
> > 
> > Compiler warning fixed by patch:
> > 
> >    In file included from tools/testing/selftests/vfio/lib/include/libvfio.h:6:
> >    tools/testing/selftests/vfio/lib/include/libvfio/iommu.h:49:2: warning: format specifies type 'unsigned long' but the argument has type 'u64' (aka 'unsigned long long') [-Wformat]
> >       49 |         VFIO_ASSERT_EQ(__iommu_unmap(iommu, region, NULL), 0);
> >          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >    tools/testing/selftests/vfio/lib/include/libvfio/assert.h:32:37: note: expanded from macro 'VFIO_ASSERT_EQ'
> >       32 | #define VFIO_ASSERT_EQ(_a, _b, ...) VFIO_ASSERT_OP(_a, _b, ==, ##__VA_ARGS__)
> >          |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >    tools/testing/selftests/vfio/lib/include/libvfio/assert.h:27:22: note: expanded from macro 'VFIO_ASSERT_OP'
> >       26 |         fprintf(stderr, "  Observed: %#lx %s %#lx\n",                           \
> >          |                                              ~~~~
> >       27 |                         (u64)__lhs, #_op, (u64)__rhs);                          \
> >          |                                           ^~~~~~~~~~
> > ---
> > Changes in v2:
> > - Add white space around arch checks
> > - Clean up uname command
> > - Link to v1: https://lore.kernel.org/r/20260130-vfio-selftest-only-64bit-v1-1-d89ac0944c01@fb.com
> > ---
> >  tools/testing/selftests/vfio/Makefile | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
> > index ead27892ab65..8e90e409e91d 100644
> > --- a/tools/testing/selftests/vfio/Makefile
> > +++ b/tools/testing/selftests/vfio/Makefile
> > @@ -1,3 +1,10 @@
> > +ARCH ?= $(shell uname -m)
> > +
> > +ifeq (,$(filter $(ARCH),arm64 x86_64))
> 
> This fails to build (i.e. elides the build) on my local arm64 machine,
> because uname -m returns 'aarch64', not 'arm64'.

I have the same issue on x86! The kernel uses x86 is the ARCH when you
run it straight from the top level make

make[4]: Entering directory '/home/jgg/oss/wip/mlx5st/tools/testing/selftests/vfio'
Makefile:1: "Saw ARCH=x86"

Even though this is a 64 bit build.

Jason