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

[Huang, Kai]

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();
      |                 ^~~~~~~~~~~~~~~~~~~~