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

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Message-ID: <l3uo3n3li27czehll2wz34xxkcv5j2vcshgp5a6w7u4h4aidpu@4oe2cwye2e6z>
Date: Thu, 1 Feb 2024 00:03:59 +0200
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Dave Hansen <dave.hansen@...el.com>
Cc: "Huang, Kai" <kai.huang@...el.com>, linux-kernel@...r.kernel.org, 
	x86@...nel.org, tglx@...utronix.de, bp@...en8.de, mingo@...hat.com, 
	hpa@...or.com, luto@...nel.org, peterz@...radead.org, thomas.lendacky@....com, 
	chao.gao@...el.com, bhe@...hat.com, nik.borisov@...e.com, pbonzini@...hat.com
Subject: Re: [PATCH 3/4] x86/kexec(): Reset TDX private memory on platforms
 with TDX erratum

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.
-- 
  Kiryl Shutsemau / Kirill A. Shutemov