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

[Baolu Lu <baolu.lu@linux.intel.com>]

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@intel.com/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@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/202603290006.za7iiDgF-lkp@intel.com/
>>>
>>> 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