Re: [PATCH] vfio: selftests: fix format conversion compiler warning

[Alex Williamson <alex@shazbot.org>]

On Wed, 28 Jan 2026 11:21:52 -0800
David Matlack <dmatlack@google.com> wrote:

> On Wed, Jan 28, 2026 at 11:12 AM Randy Dunlap <rdunlap@infradead.org> wrote:
> > On 1/28/26 11:06 AM, David Matlack wrote:  
> > > On Wed, Jan 28, 2026 at 10:38 AM Ted Logan <tedlogan@fb.com> wrote:  
> > >>
> > >> Use the standard format conversion macro PRIx64 to generate the
> > >> appropriate format conversion for 64-bit integers. Fixes a compiler
> > >> warning with -Wformat on i386.
> > >>
> > >> Signed-off-by: Ted Logan <tedlogan@fb.com>
> > >> Reported-by: kernel test robot <lkp@intel.com>
> > >> Closes: https://lore.kernel.org/oe-kbuild-all/202601211830.aBEjmEFD-lkp@intel.com/  
> > >
> > > Thanks for the patch.
> > >
> > > I've been seeing these i386 reports as well. I find the PRIx64, etc.
> > > format specifiers make format strings very hard to read. And I think
> > > there were some other issues when building VFIO selftests with i386
> > > the last time I tried.
> > >
> > > I was thinking instead we should just not support i386 builds of VFIO
> > > selftests. But I hadn't gotten around to figuring out the right
> > > Makefile magic to make that happen.  
> >
> > There are other 32-bit CPUs besides i386.
> > Or do only support X86?  
> 
> At this point I would only call x86_64 and arm64 as supported. At
> least that is all I have access to and tested.
> 
> If there is legitimate desire to run these tests on 32-bit CPUs, then
> we can support it.
> 
> Alex, do you test on 32-bit CPUs?

No, I haven't tested 32-bit in a very long time.  I'd like to think it
works, but I'm not aware of any worthwhile use case.  Thanks,

Alex