Re: [PATCH 3/4] x86/kexec(): Reset TDX private memory on platforms with TDX erratum

["Huang, Kai" <kai.huang@intel.com>]

On 1/02/2024 6:03 am, Kirill A. Shutemov wrote:
> On Wed, Jan 31, 2024 at 01:21:39PM -0800, Dave Hansen wrote:
>>>   #ifdef CONFIG_KEXEC_JUMP
>>>   	if (image->preserve_context)
>>>   		save_processor_state();
>>> +	else
>>> +		tdx_reset_memory();
>>> +#else
>>> +	tdx_reset_memory();
>>>   #endif
>>
>> Wow, that's awfully hard to read.  I really wish folks' gag reflex would
>> kick in when they see stuff like this to get them to spend an additional
>> 15 seconds to turn this into:
>>
>> 	if (IS_ENABLED(CONFIG_KEXEC_JUMP) && image->preserve_context)
>> 		save_processor_state();
>> 	else
>> 		tdx_reset_memory();
> 
> save_processor_state() is declared under CONFIG_PM_SLEEP, so I guess your
> variant might break build in some cases without updated suspend.h.

I tried.  If I turn off both SUSPEND and HIBERNATION in the Kconfig I 
got build error：

arch/x86/kernel/machine_kexec_64.c:325:17: error: implicit declaration 
of function ‘save_processor_state’ [-Werror=implicit-function-declaration]
   325 |                 save_processor_state();
       |                 ^~~~~~~~~~~~~~~~~~~~