Re: [PATCH v2 19/31] iommu/vt-d: Reserve the MSB domain ID bit for the TDX module

[Baolu Lu]

On 4/8/26 20:07, Xu Yilun wrote:
> On Tue, Mar 31, 2026 at 03:20:44PM +0800, Baolu Lu wrote:
> > On 3/29/26 00:57, kernel test robot wrote:
> > > kernel test robot noticed the following build warnings:
> > >
> > > [auto build test WARNING on 11439c4635edd669ae435eec308f4ab8a0804808]
> > >
> > > url:https://github.com/intel-lab-lkp/linux/commits/Xu-Yilun/x86-tdx-Move-
> > > all-TDX-error-defines-into-asm-shared-tdx_errno-h/20260328-151524
> > > base:   11439c4635edd669ae435eec308f4ab8a0804808
> > > patch link:https://lore.kernel.org/r/20260327160132.2946114-20-
> > > yilun.xu%40linux.intel.com
> > > patch subject: [PATCH v2 19/31] iommu/vt-d: Reserve the MSB domain ID bit for the TDX module
> > > config: i386-randconfig-141-20260328
> > > (https://download.01.org/0day-ci/archive/20260329/202603290006.za7iiDgF-
> > > lkp@xxxxxxxxx/config)
> > > compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> > > smatch: v0.5.0-9004-gb810ac53
> > > reproduce (this is a W=1 build):
> > > (https://download.01.org/0day-ci/archive/20260329/202603290006.za7iiDgF-
> > > lkp@xxxxxxxxx/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@xxxxxxxxx>
> > > | Closes:https://lore.kernel.org/oe-kbuild-all/202603290006.za7iiDgF-lkp@xxxxxxxxx/
> > >
> > > All warnings (new ones prefixed by >>, old ones prefixed by <<):
> > >
> > > > > WARNING: modpost: vmlinux: section mismatch in reference: iommu_max_domain_id+0x55 (section: .text.iommu_max_domain_id) -> acpi_table_parse_keyp (section: .init.text)
> >
> >
> > acpi_table_parse_keyp() is marked as __init. But this patch causes the
> > intel iommu driver to call it from a runtime function.
> >
> > int __init_or_acpilib
> > acpi_table_parse_keyp(enum acpi_keyp_type id,
> >                        acpi_tbl_entry_handler_arg handler_arg, void *arg)
> > {
> >          return __acpi_table_parse_entries(ACPI_SIG_KEYP,
> >                                            sizeof(struct acpi_table_keyp),
> > id,
> >                                            NULL, handler_arg, arg, 0);
> > }
>
> Is it better we configure ACPI table as library, so that drivers could
> use it freely at runtime? tdx-host also uses this function.
>
> --------8<--------
>
> diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
> index 5471f814e073..55188d6d38bb 100644
> --- a/drivers/iommu/intel/Kconfig
> +++ b/drivers/iommu/intel/Kconfig
> @@ -1,6 +1,7 @@
>   # SPDX-License-Identifier: GPL-2.0-only
>   # Intel IOMMU support
>   config DMAR_TABLE
> +       select ACPI_TABLE_LIB
>          bool
>
>   config DMAR_PERF

This looks better.

Thanks,
baolu