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Subject: Re: [RFC v2 26/32] x86/mm: Move force_dma_unencrypted() to common
 code
To:     Dave Hansen <dave.hansen@intel.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        Raj Ashok <ashok.raj@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        linux-kernel@vger.kernel.org
References: <cover.1619458733.git.sathyanarayanan.kuppuswamy@linux.intel.com>
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 <bbcb688c-5aa0-eeb1-192a-45edaccc2f32@intel.com>
 <20210512130821.7r2rtzcyjltecun7@box.shutemov.name>
 <e8886298-83fa-212e-ab3a-5e5b21a7ab6c@intel.com>
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
Message-ID: <3ad7a35d-45f2-9c62-23cd-3b7a167c5d83@linux.intel.com>
Date:   Mon, 17 May 2021 18:28:11 -0700
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On 5/12/21 8:44 AM, Dave Hansen wrote:
> Because the code is already separate.  You're actually going to some
> trouble to move the SEV-specific code and then combine it with the
> TDX-specific code.
> 
> Anyway, please just give it a shot.  Should take all of ten minutes.  If
> it doesn't work out in practice, fine.  You'll have a good paragraph for
> the changelog.

After reviewing the code again, I have noticed that we don't really have
much common code between AMD and TDX. So I don't see any justification for
creating this common layer. So, I have decided to drop this patch and move
Intel TDX specific memory encryption init code to patch titled "[RFC v2 30/32]
x86/tdx: Make DMA pages shared". This model is similar to how AMD-SEV
does the initialization.

I have sent the modified patch as reply to patch titled "[RFC v2 30/32]
x86/tdx: Make DMA pages shared". Please check and let me know your comments.
-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer