From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0E1B533F0 for ; Thu, 26 Jan 2023 16:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674750333; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CyqC4HBKoEgyHHDtYb2+ga2T4D19HRBTg8u+WniVOaQ=; b=d35bFUcUlSUSSOz7O7/+RMF2P+0Xxk1GpzKQp4/+dybdWDGiaCL6z0dR18NVw+AKLhNK00 XG/WhPjiP+3Se3C+ASbpTuNWpqlxSNWApnYsNaJFGTjZplPVF6/8HH0e5mcKSIWx4eALYG s8jJcLo6DuOHWKgXL3hbn80kBb0G1O8= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-90-2H9cPzB3PZmUbalQewq9dQ-1; Thu, 26 Jan 2023 11:25:29 -0500 X-MC-Unique: 2H9cPzB3PZmUbalQewq9dQ-1 Received: by mail-wr1-f72.google.com with SMTP id l8-20020adfc788000000b002bdfe72089cso428192wrg.21 for ; Thu, 26 Jan 2023 08:25:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=CyqC4HBKoEgyHHDtYb2+ga2T4D19HRBTg8u+WniVOaQ=; b=w3yKQVZq55Bwc4vsbgCsX3N1RYlEtNYG4saZne3FGa3bYyZ/AAz0FnY9FbQXr5+7Nv Q4moMm1C5gZqrItUUP31WvofUuoNoYOSXNaNTPTIuU3tWO40i/5w5lhKb2UuCpqKMVk1 ZzaCRYTtC8fINsAFFRo5HjxDGwNyl1u5Y8RXMIVYtbluEnjJv38JrF2MP+n1xmrMfOJB VsaofpigMABUmyoZPlhnYj7YfD8uJbkAkSEW1uCEeXsS2Ee2L0rSgN8rJaiFNyFvAC6m iD/v2gWuT7Y3s7kxBhRUlDlEFwURKl/LM0VQHW3aetEmZJeVDJz5vr+mgDH1Xi7BCwed HOLA== X-Gm-Message-State: AFqh2kotwZxDHvyruNJAnTvxaa0Ko5EUQVwtJP3pF0jFaTgU1hbNCnfs MESStKfVbNv5W/sP76qlijJoXWHxSlNj6fasxzVtB+nWc62FXhFtpmo/072skJ3dquegGnUjCsz Rm7uysxiVB1jMmfnVDQFR2g== X-Received: by 2002:a05:600c:3488:b0:3cf:68f8:790b with SMTP id a8-20020a05600c348800b003cf68f8790bmr33587603wmq.11.1674750327871; Thu, 26 Jan 2023 08:25:27 -0800 (PST) X-Google-Smtp-Source: AMrXdXv5e8MKjFsCkVUne5IjgyuScDl6uyyRaHtc0mBQA3MKSQ6ykJ/gLCNS/1L73hNUG/JIUAeP8g== X-Received: by 2002:a05:600c:3488:b0:3cf:68f8:790b with SMTP id a8-20020a05600c348800b003cf68f8790bmr33587572wmq.11.1674750327685; Thu, 26 Jan 2023 08:25:27 -0800 (PST) Received: from redhat.com ([2.52.137.69]) by smtp.gmail.com with ESMTPSA id c11-20020adfa30b000000b002bfb5ebf8cfsm1822818wrb.21.2023.01.26.08.25.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Jan 2023 08:25:26 -0800 (PST) Date: Thu, 26 Jan 2023 11:25:21 -0500 From: "Michael S. Tsirkin" To: Lukas Wunner Cc: Samuel Ortiz , "Dr. David Alan Gilbert" , Greg Kroah-Hartman , "Reshetova, Elena" , "Shishkin, Alexander" , "Shutemov, Kirill" , "Kuppuswamy, Sathyanarayanan" , "Kleen, Andi" , "Hansen, Dave" , Thomas Gleixner , Peter Zijlstra , Mika Westerberg , Jason Wang , "Poimboe, Josh" , "aarcange@redhat.com" , Cfir Cohen , Marc Orr , "jbachmann@google.com" , "pgonda@google.com" , "keescook@chromium.org" , James Morris , Michael Kelley , "Lange, Jon" , "linux-coco@lists.linux.dev" , Linux Kernel Mailing List , Jonathan Cameron , linux-pci@vger.kernel.org Subject: Re: Linux guest kernel threat model for Confidential Computing Message-ID: <20230126112058-mutt-send-email-mst@kernel.org> References: <20230125215333.GA18160@wunner.de> <20230126154449.GB4188@wunner.de> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20230126154449.GB4188@wunner.de> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Jan 26, 2023 at 04:44:49PM +0100, Lukas Wunner wrote: > Obviously the host can DoS guest access to the device by modifying > exchanged messages, but there are much simpler ways for it to > do that, say, by clearing Bus Master Enable or Memory Space Enable > bits in the Command Register. There's a single key per guest though, isn't it? Also used for regular memory? -- MST