linux-kernel - Re: [PATCH v3 3/6] x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum

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Message-ID: <4ca0db300edead0bfc09e81e43895ac20dce521e.camel@intel.com>
Date: Wed, 2 Jul 2025 03:12:06 +0000
From: "Huang, Kai" <kai.huang@...el.com>
To: "Hansen, Dave" <dave.hansen@...el.com>, "bp@...en8.de" <bp@...en8.de>,
	"binbin.wu@...ux.intel.com" <binbin.wu@...ux.intel.com>,
	"peterz@...radead.org" <peterz@...radead.org>, "hpa@...or.com"
	<hpa@...or.com>, "mingo@...hat.com" <mingo@...hat.com>, "tglx@...utronix.de"
	<tglx@...utronix.de>, "thomas.lendacky@....com" <thomas.lendacky@....com>
CC: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>, "seanjc@...gle.com"
	<seanjc@...gle.com>, "x86@...nel.org" <x86@...nel.org>, "sagis@...gle.com"
	<sagis@...gle.com>, "Chatre, Reinette" <reinette.chatre@...el.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
	"Williams, Dan J" <dan.j.williams@...el.com>, "kvm@...r.kernel.org"
	<kvm@...r.kernel.org>, "pbonzini@...hat.com" <pbonzini@...hat.com>,
	"Yamahata, Isaku" <isaku.yamahata@...el.com>, "ashish.kalra@....com"
	<ashish.kalra@....com>, "Chen, Farrah" <farrah.chen@...el.com>,
	"nik.borisov@...e.com" <nik.borisov@...e.com>
Subject: Re: [PATCH v3 3/6] x86/kexec: Disable kexec/kdump on platforms with
 TDX partial write erratum


> > +	/*
> > +	 * Some early TDX-capable platforms have an erratum.  A kernel
> > +	 * partial write (a write transaction of less than cacheline
> > +	 * lands at memory controller) to TDX private memory poisons that
> > +	 * memory, and a subsequent read triggers a machine check.
> > +	 *
> Nit: About the description of the erratum, maybe it's better to refer to the
> comments of check_tdx_erratum() to avoid duplication. Also it gives a link to
> how/when the bug is set.

I am not sure pointing to the comment at another place is desired,
especially at another file.  It could be done in some cases but IMHO in
general it's better to have a "standalone" comment so we don't need to jump
back and forth, or need to care about the case that the other comment could
be updated etc.

> 
> Otherwise,
> Reviewed-by: Binbin Wu <binbin.wu@...ux.intel.com>

Thanks.