ERROR: modpost: "__pt_no_sw_bit" [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!

ERROR: modpost: "__pt_no_sw_bit" [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   b927546677c876e26eba308550207c2ddf812a43
commit: efa03dab7ce4ed786b131f412440e2fd45fba11f iommupt: Flush the CPU cache after any writes to the page table
date:   7 weeks ago
config: powerpc64-randconfig-r051-20251223 (https://download.01.org/0day-ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/config)
compiler: powerpc64-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/reproduce)

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 <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512230720.9y9DtWIo-lkp@intel.com/

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__pt_no_sw_bit" [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

RE: ERROR: modpost: "__pt_no_sw_bit" [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!

[Tian, Kevin]

> From: lkp <lkp@intel.com>
> Sent: Tuesday, December 23, 2025 7:25 AM
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> master
> head:   b927546677c876e26eba308550207c2ddf812a43
> commit: efa03dab7ce4ed786b131f412440e2fd45fba11f iommupt: Flush the
> CPU cache after any writes to the page table
> date:   7 weeks ago
> config: powerpc64-randconfig-r051-20251223
> (https://download.01.org/0day-
> ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/config)
> compiler: powerpc64-linux-gcc (GCC) 8.5.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-
> ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/reproduce)
> 
> 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 <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202512230720.9y9DtWIo-
> lkp@intel.com/
> 
> All errors (new ones prefixed by >>, old ones prefixed by <<):
> 
> >> ERROR: modpost: "__pt_no_sw_bit"
> [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!
> 

Jason, are you deliberately leaving it undefined to catch config which shouldn't
compile generic_pt in, or is it indeed a bug?

seems on x86 pt_feature() is inline built so all the reference to __pt_no_sw_bit
is removed statically due to:

        if (!PT_SUPPORTED_FEATURE(feature_nr))
                return false;

but ppc64 builds pt_feature() as an external symbol then hitting trouble on
undefined __pt_no_sw_bit...

Thanks
Kevin

Re: ERROR: modpost: "__pt_no_sw_bit" [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!

[Jason Gunthorpe]

On Tue, Jan 06, 2026 at 08:09:27AM +0000, Tian, Kevin wrote:
> > From: lkp <lkp@intel.com>
> > Sent: Tuesday, December 23, 2025 7:25 AM
> > 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > master
> > head:   b927546677c876e26eba308550207c2ddf812a43
> > commit: efa03dab7ce4ed786b131f412440e2fd45fba11f iommupt: Flush the
> > CPU cache after any writes to the page table
> > date:   7 weeks ago
> > config: powerpc64-randconfig-r051-20251223
> > (https://download.01.org/0day-
> > ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/config)
> > compiler: powerpc64-linux-gcc (GCC) 8.5.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-
> > ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/reproduce)
> > 
> > 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 <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202512230720.9y9DtWIo-
> > lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>, old ones prefixed by <<):
> > 
> > >> ERROR: modpost: "__pt_no_sw_bit"
> > [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!
> > 
> 
> Jason, are you deliberately leaving it undefined to catch config which shouldn't
> compile generic_pt in, or is it indeed a bug?

I think this was already fixed:

https://lore.kernel.org/all/0-v1-63a2cffb09da+4486-iommufd_gcc_bounds_jgg@nvidia.com/

commit efa03dab7ce4ed786b131f412440e2fd45fba11f does not have that
change.

Jason

RE: ERROR: modpost: "__pt_no_sw_bit" [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!

[Tian, Kevin]

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Tuesday, January 6, 2026 9:28 PM
> 
> On Tue, Jan 06, 2026 at 08:09:27AM +0000, Tian, Kevin wrote:
> > > From: lkp <lkp@intel.com>
> > > Sent: Tuesday, December 23, 2025 7:25 AM
> > >
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > > master
> > > head:   b927546677c876e26eba308550207c2ddf812a43
> > > commit: efa03dab7ce4ed786b131f412440e2fd45fba11f iommupt: Flush
> the
> > > CPU cache after any writes to the page table
> > > date:   7 weeks ago
> > > config: powerpc64-randconfig-r051-20251223
> > > (https://download.01.org/0day-
> > > ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/config)
> > > compiler: powerpc64-linux-gcc (GCC) 8.5.0
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-
> > > ci/archive/20251223/202512230720.9y9DtWIo-lkp@intel.com/reproduce)
> > >
> > > 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 <lkp@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202512230720.9y9DtWIo-
> > > lkp@intel.com/
> > >
> > > All errors (new ones prefixed by >>, old ones prefixed by <<):
> > >
> > > >> ERROR: modpost: "__pt_no_sw_bit"
> > > [drivers/iommu/generic_pt/fmt/iommu_amdv1.ko] undefined!
> > >
> >
> > Jason, are you deliberately leaving it undefined to catch config which
> shouldn't
> > compile generic_pt in, or is it indeed a bug?
> 
> I think this was already fixed:

I pulled rc4. still can observe the error.

> 
> https://lore.kernel.org/all/0-v1-63a2cffb09da+4486-
> iommufd_gcc_bounds_jgg@nvidia.com/
> 

that seems to fix an out-of-bound selftest error. Not about this one?