linux-kernel - Re: [PATCH] x86: tdx: hide unused tdx_dump_mce

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Message-ID: <20231213120215.64wcryk5k75cymop@box>
Date:   Wed, 13 Dec 2023 15:02:15 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To:     Dave Hansen <dave.hansen@...el.com>
Cc:     Arnd Bergmann <arnd@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        Yuan Yao <yuan.yao@...el.com>, Kai Huang <kai.huang@...el.com>,
        Tony Luck <tony.luck@...el.com>, Arnd Bergmann <arnd@...db.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Isaku Yamahata <isaku.yamahata@...el.com>,
        linux-coco@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] x86: tdx: hide unused tdx_dump_mce_info()

On Tue, Dec 12, 2023 at 01:42:09PM -0800, Dave Hansen wrote:
> On 12/12/23 13:36, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@...db.de>
> > 
> > When TDX is enabled but MCE is not, the tdx_dump_mce_info() function
> > fails to link:
> 
> Thanks for the report, Arnd.
> 
> The only way that TDX has to report integrity errors is an MCE.  I'm not
> sure it even makes sense to have TDX support but not MCE support.  Maybe
> we should just make TDX host support depend on MCE.

I agree. Silently ignore integrity errors is not good idea.

TDX module spec also supports it:

"The machine-check exception handler is expected to be implemented in the
VMM."

-- 
  Kiryl Shutsemau / Kirill A. Shutemov