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

[David Matlack]

On Mon, Feb 2, 2026 at 1:46 PM Alex Williamson <alex@xxxxxxxxxxx> wrote:
>
> On Fri, 30 Jan 2026 16:02:16 -0800
> Ted Logan <tedlogan@xxxxxx> 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@xxxxxxxxx>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202601211830.aBEjmEFD-lkp@xxxxxxxxx/
> > Signed-off-by: Ted Logan <tedlogan@xxxxxx>
> > ---
> > 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);                          \
> >          |                                           ^~~~~~~~~~
> > ---
> >  tools/testing/selftests/vfio/Makefile | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
> > index ead27892ab65..eeb63ea2b4da 100644
> > --- a/tools/testing/selftests/vfio/Makefile
> > +++ b/tools/testing/selftests/vfio/Makefile
> > @@ -1,3 +1,10 @@
> > +ARCH ?= $(shell uname -m 2>/dev/null || echo not)
> > +
> > +ifeq (,$(filter $(ARCH),arm64 x86_64))
> > +nothing:
> > +.PHONY: all clean run_tests install
> > +.SILENT:
> > +else
> >  CFLAGS = $(KHDR_INCLUDES)
> >  TEST_GEN_PROGS += vfio_dma_mapping_test
> >  TEST_GEN_PROGS += vfio_dma_mapping_mmio_test
> > @@ -28,3 +35,4 @@ TEST_DEP_FILES = $(patsubst %.o, %.d, $(TEST_GEN_PROGS_O) $(LIBVFIO_O))
> >  -include $(TEST_DEP_FILES)
> >
> >  EXTRA_CLEAN += $(TEST_GEN_PROGS_O) $(TEST_DEP_FILES)
> > +endif
>
> I see other Makefiles include tools/scripts/Makefile.arch which would
> then just let us test for 'ifeq (${IS_64_BIT}, 1)'.  Would that more
> directly address what we're trying to solve here?  Thanks,

I gave this a try but it seems like it results in a tricky situation.
We must include tools/testing/selftests/lib.mk before
tools/scripts/Makefile.arch so that $(CC) and $(CFLAGS) is set
correctly. But TEST_GEN_* variables have to be defined before the
include of tools/testing/selftests/lib.mk, which is what Ted is trying
to avoid :(.