Re: [kvm-x86:selftests2] [KVM] a262fc49e0: kselftests.kvm.make.fail

[David Matlack <dmatlack@google.com>]

On 2026-08-07 10:21 PM, David Matlack wrote:
> On 2026-08-07 11:35 AM, Sean Christopherson wrote:
> > On Fri, Aug 07, 2026, kernel test robot wrote:
> > > 
> > > 
> > > Hello,
> > > 
> > > kernel test robot noticed "kselftests.kvm.make.fail" on:
> > > 
> > > commit: a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757 ("KVM: selftests: Build and link selftests/vfio/lib into KVM selftests")
> > > https://github.com/kvm-x86/linux selftests2
> > > 
> > > [test failed on linux-next/master 78bc8af4affb9a732504eb22eeac7d1e50883853]
> > > 
> > > in testcase: kselftests
> > > version: kselftests-x86_64-848acc8ffe1b-1_20260804
> > > with following parameters:
> > > 
> > > 	group: kvm
> > > 
> > > 
> > > config: x86_64-rhel-9.4-kselftests
> > > compiler: gcc-14
> > > test machine: 224 threads 2 sockets Intel(R) Xeon(R) Platinum 8480CTDX (Sapphire Rapids) with 256G memory
> > > 
> > > (please refer to attached dmesg/kmsg for entire log/backtrace)
> > > 
> > > 
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <oliver.sang@intel.com>
> > > | Closes: https://lore.kernel.org/oe-lkp/202608071656.86e9fd06-lkp@intel.com
> > > 
> > > 
> > > /usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/vfio/lib/drivers/ioat/ioat.c:12:10: fatal error: hw.h: No such file or directory
> > >    12 | #include "hw.h"
> > >       |          ^~~~~~
> > > compilation terminated.
> > > make[1]: *** [../vfio/lib/libvfio.mk:32:
> > > /usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/kvm/libvfio/drivers/ioat/ioat.o]
> > > Error 1 make[1]: *** Waiting for unfinished jobs....
> > > /usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/vfio/lib/drivers/dsa/dsa.c:14:10:
> > > fatal error: registers.h: No such file or directory
> > >    14 | #include "registers.h"
> > >       |          ^~~~~~~~~~~~~
> > > compilation terminated.
> > > make[1]: *** [../vfio/lib/libvfio.mk:32:
> > > /usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/kvm/libvfio/drivers/dsa/dsa.o]
> > > Error 1 make[1]: Leaving directory
> > > '/usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/kvm'
> > > make: *** [Makefile:218: all] Error 2
> > 
> > Any chance the file is literally just not there?  Makefile.kvm's -I$(<D) expands
> > to:
> > 
> >  -I/usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/vfio/lib/drivers/dsa
> > 
> > which matches the directory of the input file:
> > 
> >  -c/usr/src/perf_selftests-x86_64-rhel-9.4-kselftests-a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757/tools/testing/selftests/vfio/lib/drivers/dsa/dsa.c
> > 
> > so AFAICT the makefile is working as intended?
> 
> I think this is a problem in how the kernel test robot builds selftests.
> 
> hw.h and registers.h are symlinks to headers in the kernel source tree.
> The selftests build works fine for me when I check out the entire kernel
> tree at commit a262fc49e0aafdeeb1b4fd8cb0d79a0fde447757 and build the
> KVM selftests.
> 
> But if I delete one of the symlink destinations, I see the same error.
> 
> $ ls -l tools/testing/selftests/vfio/lib/drivers/dsa/registers.h
> [...] tools/testing/selftests/vfio/lib/drivers/dsa/registers.h -> ../../../../../../../drivers/dma/idxd/registers.h
> 
> $ rm drivers/dma/idxd/registers.h
> 
> $ make -C tools/testing/selftests/kvm -s
> /usr/local/google/home/dmatlack/kernel/trees/kvm/tools/testing/selftests/vfio/lib/drivers/dsa/dsa.c:14:10: fatal error: registers.h: No such file or directory
>    14 | #include "registers.h"
>       |          ^~~~~~~~~~~~~
> compilation terminated.
> make: *** [../vfio/lib/libvfio.mk:32: /usr/local/google/home/dmatlack/kernel/trees/kvm/tools/testing/selftests/kvm/libvfio/drivers/dsa/dsa.o] Error 1
> 
> Maybe the kernel test robot doesn't download the entire kernel tree when
> building selftests?

Yeah this seems to be the cause of the build failure. The lkp project
only grabs a subset of the kernel directories when packaging up the
kernel to build selftests, so it will not have access to the symlink
targets used by VFIO selftests:

  https://github.com/intel/lkp-tests/blob/bbbc29c495d9617f28dbc8b799cf0dac9a1ca54e/lib/tests/pkgbuild.sh#L484

I'll get the ball rolling on fixing this in lkp.