linux-kernel - Re: [RFC v2 26/32] x86/mm: Move force_dma

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3ad7a35d-45f2-9c62-23cd-3b7a167c5d83@linux.intel.com>
Date:   Mon, 17 May 2021 18:28:11 -0700
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
To:     Dave Hansen <dave.hansen@...el.com>,
        "Kirill A. Shutemov" <kirill@...temov.name>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        Raj Ashok <ashok.raj@...el.com>,
        Sean Christopherson <seanjc@...gle.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [RFC v2 26/32] x86/mm: Move force_dma_unencrypted() to common
 code



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