Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3E53C05027 for ; Thu, 26 Jan 2023 16:33:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230244AbjAZQdu (ORCPT ); Thu, 26 Jan 2023 11:33:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229529AbjAZQds (ORCPT ); Thu, 26 Jan 2023 11:33:48 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DC9916AE3 for ; Thu, 26 Jan 2023 08:33:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674750780; 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=ina2piJFWXlFGrmY00Oh76hBYD3Ot4A56CWMmj58vpUebYO06P5sKEZszmLHZIgqx2X9rU qeTMfDgn3Nko++dH1Ufe1UXZWyES3G7ADxlgLl2SkweHdigSdW8y+sSAcM7N4kpyhvjKLs 6i/dyQFQroPblWKpG8g9xTciuILV660= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-204-CPGuSA0aPUiAf8g2i5OztQ-1; Thu, 26 Jan 2023 11:25:29 -0500 X-MC-Unique: CPGuSA0aPUiAf8g2i5OztQ-1 Received: by mail-wr1-f71.google.com with SMTP id w23-20020adf8bd7000000b002bfbf6f23feso426182wra.18 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=7TOkUgR6KjldN6yzyWD6TCaIi2BgmnlL4azD2+a9GqWGeW91/+Z+ipnwgZk/0o3moi RSWuEErGZaIsagbBg8EdcqIjBohjznBqurgy904ZCSS1goOt61qB7hgliJ9xFgK4BxxJ ShkR11zzbSZ3zai1wp9zA8ieh/LZKSeXX/Q9f2Ix5CDkbvJvOHN1kPZ3yCni+f0E1Je+ dO4LM9SLNVzAJ1vvXMhCdfiVbtBI00ySk/YVBHqcompvZMTDRtF8cxO3n7ZYjDDgAJpx 6hodawW/DOmhjlfVEi4foKn2K45oeMLdKlH+YThBq1LGGPjXt7AjKnTFAqylQrRxxDg4 jSpA== X-Gm-Message-State: AFqh2kqOzJidLAs41ni3l5iyYATiFUfwhNqwlbEizJbFYkGZ2IrrV39d vgS1K1s9BXrTa9USJAiyBoneyjw1rRkIgR5shbAEY2JprlPKyLlzx70i+Uquvxo+HAoGvUg4yby R9NkSqrY06KMmApv+ip2itE28 X-Received: by 2002:a05:600c:3488:b0:3cf:68f8:790b with SMTP id a8-20020a05600c348800b003cf68f8790bmr33587598wmq.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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230126154449.GB4188@wunner.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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