linux-kernel - Re: [PATCH v5 06/12] x86/tdx: Get TD execution environment information via TDINFO

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Message-ID: <428c09d3-f636-2a99-e394-e46b57c38b29@linux.intel.com>
Date:   Fri, 20 Aug 2021 12:01:04 -0700
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
To:     Andi Kleen <ak@...ux.intel.com>, Borislav Petkov <bp@...en8.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Peter H Anvin <hpa@...or.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 06/12] x86/tdx: Get TD execution environment
 information via TDINFO



On 8/20/21 11:58 AM, Andi Kleen wrote:
> 
> 
> Without working TDCALLs the error message won't appear anywhere. The only practical way to debug 
> such a problem is a kernel debugger.
> 
> Also printing an error message might end up recursing because the console write would trigger TDCALL 
> again, or eventually stop because the console lock is already taken. In any case it won't work.

Yes, good point. In this case, adding debug print will not work. But I
can add more comments to the code.

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer