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Message-ID: <1182ef92-cae3-b7c1-8339-8e8bfa48f2e3@linux.intel.com>
Date:   Wed, 14 Sep 2022 08:36:10 -0700
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Subject: Re: [PATCH v13 1/3] x86/tdx: Add TDX Guest attestation interface
 driver
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To:     Dave Hansen <dave.hansen@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        Shuah Khan <shuah@kernel.org>
Cc:     "H . Peter Anvin" <hpa@zytor.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kai Huang <kai.huang@intel.com>,
        Wander Lairson Costa <wander@redhat.com>,
        Isaku Yamahata <isaku.yamahata@gmail.com>,
        marcelo.cerri@canonical.com, tim.gardner@canonical.com,
        khalid.elmously@canonical.com, philip.cox@canonical.com,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        linux-doc@vger.kernel.org
References: <20220909192708.1113126-1-sathyanarayanan.kuppuswamy@linux.intel.com>
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 <7c3cc265-869b-b2fc-43f2-d2cbd0bc142c@intel.com>
From:   Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
In-Reply-To: <7c3cc265-869b-b2fc-43f2-d2cbd0bc142c@intel.com>
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On 9/14/22 4:36 AM, Dave Hansen wrote:
> On 9/9/22 12:27, Kuppuswamy Sathyanarayanan wrote:
>>
>>  arch/x86/coco/tdx/tdx.c         | 115 ++++++++++++++++++++++++++++++++
>>  arch/x86/include/uapi/asm/tdx.h |  56 ++++++++++++++++
>>  2 files changed, 171 insertions(+)
>>  create mode 100644 arch/x86/include/uapi/asm/tdx.h
> 
> The SEV equivalent of this in in:
> 
> 	drivers/virt/coco/sev-guest/sev-guest.c
> 
> right?
> 
> Why did you choose a different location?  Also, can you please study the

When we initially submitted the attestation patches, virt/coco folder
was not created. I initially kept this driver in platform/x86/, but
later moved to arch/x86/coco based on the review comments in v4. There
was a discussion about the need for a new config and the location of
the driver. The outcome of that discussion is, since this is not a
traditional driver, but a basic TDX feature, we don't need a special
config and the code can be maintained in the arch/x86/coco folder.

https://lore.kernel.org/lkml/YmEfgn7fMcZ2oCnr@zn.tnic/

> SEV implementation a bit?  It might help you find problems like the
> ioctl() return code issue.  The SEV driver appears to have gotten that
> right.

Ok.

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer