Re: [PATCH v2 4/5] x86/virt/tdx: Remove the !KEXEC_CORE dependency

Re: [PATCH v2 4/5] x86/virt/tdx: Remove the !KEXEC_CORE dependency

[kernel test robot]

Hi Kai,

kernel test robot noticed the following build errors:

[auto build test ERROR on 5b036d3516a8be54c24c05d8d1dc86f9815ba53e]

url:    https://github.com/intel-lab-lkp/linux/commits/Kai-Huang/x86-sme-Use-percpu-boolean-to-control-wbinvd-during-kexec/20250510-192315
base:   5b036d3516a8be54c24c05d8d1dc86f9815ba53e
patch link:    https://lore.kernel.org/r/0c0d9d250a7961e4aca325f970e73e204d650ad9.1746874095.git.kai.huang%40intel.com
patch subject: [PATCH v2 4/5] x86/virt/tdx: Remove the !KEXEC_CORE dependency
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20250511/202505110749.3WJFCO0R-lkp@intel.com/config)
compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250511/202505110749.3WJFCO0R-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/202505110749.3WJFCO0R-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/x86/coco/tdx/debug.c:8:
>> arch/x86/include/asm/tdx.h:109:2: error: call to undeclared function 'preempt_disable'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     109 |         preempt_disable();
         |         ^
>> arch/x86/include/asm/tdx.h:127:2: error: call to undeclared function 'preempt_enable'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     127 |         preempt_enable();
         |         ^
   2 errors generated.


vim +/preempt_disable +109 arch/x86/include/asm/tdx.h

1e66a7e27539305 Kai Huang 2023-12-08  103  
448631f05539246 Kai Huang 2025-05-10  104  static inline u64 do_seamcall(sc_func_t func, u64 fn,
448631f05539246 Kai Huang 2025-05-10  105  			      struct tdx_module_args *args)
448631f05539246 Kai Huang 2025-05-10  106  {
448631f05539246 Kai Huang 2025-05-10  107  	u64 ret;
448631f05539246 Kai Huang 2025-05-10  108  
448631f05539246 Kai Huang 2025-05-10 @109  	preempt_disable();
448631f05539246 Kai Huang 2025-05-10  110  
448631f05539246 Kai Huang 2025-05-10  111  	/*
448631f05539246 Kai Huang 2025-05-10  112  	 * SEAMCALLs are made to the TDX module and can generate dirty
448631f05539246 Kai Huang 2025-05-10  113  	 * cachelines of TDX private memory.  Mark cache state incoherent
448631f05539246 Kai Huang 2025-05-10  114  	 * so that the cache can be flushed during kexec.
448631f05539246 Kai Huang 2025-05-10  115  	 *
448631f05539246 Kai Huang 2025-05-10  116  	 * Not all SEAMCALL leaf functions generate dirty cachelines
448631f05539246 Kai Huang 2025-05-10  117  	 * but for simplicity just treat all of them do.
448631f05539246 Kai Huang 2025-05-10  118  	 *
448631f05539246 Kai Huang 2025-05-10  119  	 * This needs to be done before actually making the SEAMCALL,
448631f05539246 Kai Huang 2025-05-10  120  	 * because kexec-ing CPU could send NMI to stop remote CPUs,
448631f05539246 Kai Huang 2025-05-10  121  	 * in which case even disabling IRQ won't help here.
448631f05539246 Kai Huang 2025-05-10  122  	 */
448631f05539246 Kai Huang 2025-05-10  123  	this_cpu_write(cache_state_incoherent, true);
448631f05539246 Kai Huang 2025-05-10  124  
448631f05539246 Kai Huang 2025-05-10  125  	ret = func(fn, args);
448631f05539246 Kai Huang 2025-05-10  126  
448631f05539246 Kai Huang 2025-05-10 @127  	preempt_enable();
448631f05539246 Kai Huang 2025-05-10  128  
448631f05539246 Kai Huang 2025-05-10  129  	return ret;
448631f05539246 Kai Huang 2025-05-10  130  }
448631f05539246 Kai Huang 2025-05-10  131  

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