From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77928C43214 for ; Tue, 24 Aug 2021 20:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6351E61040 for ; Tue, 24 Aug 2021 20:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234921AbhHXUOw (ORCPT ); Tue, 24 Aug 2021 16:14:52 -0400 Received: from mga03.intel.com ([134.134.136.65]:27696 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232099AbhHXUOv (ORCPT ); Tue, 24 Aug 2021 16:14:51 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10086"; a="217426630" X-IronPort-AV: E=Sophos;i="5.84,348,1620716400"; d="scan'208";a="217426630" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2021 13:14:05 -0700 X-IronPort-AV: E=Sophos;i="5.84,348,1620716400"; d="scan'208";a="526813111" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.119.65]) ([10.209.119.65]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2021 13:14:03 -0700 Subject: Re: [PATCH v4 11/15] pci: Add pci_iomap_shared{,_range} To: Bjorn Helgaas Cc: "Michael S. Tsirkin" , Dan Williams , "Kuppuswamy, Sathyanarayanan" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , Bjorn Helgaas , Richard Henderson , Thomas Bogendoerfer , James E J Bottomley , Helge Deller , "David S . Miller" , Arnd Bergmann , Jonathan Corbet , Peter H Anvin , Dave Hansen , Tony Luck , Kirill Shutemov , Sean Christopherson , Kuppuswamy Sathyanarayanan , X86 ML , Linux Kernel Mailing List , Linux PCI , linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch , Linux Doc Mailing List , virtualization@lists.linux-foundation.org, Rajat Jain References: <20210824185541.GA3485816@bjorn-Precision-5520> From: Andi Kleen Message-ID: Date: Tue, 24 Aug 2021 13:14:02 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210824185541.GA3485816@bjorn-Precision-5520> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On 8/24/2021 11:55 AM, Bjorn Helgaas wrote: > [+cc Rajat; I still don't know what "shared memory with a hypervisor > in a confidential guest" means, A confidential guest is a guest which uses memory encryption to isolate itself from the host. It doesn't trust the host. But it still needs to communicate with the host for IO, so it has some special memory areas that are explicitly marked shared. These are used to do IO with the host. All their usage needs to be carefully hardened to avoid any security attacks on the guest, that's why we want to limit this interaction only to a small set of hardened drivers. For MMIO, the set is currently only virtio and MSI-X. -Andi From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77253C4338F for ; Tue, 24 Aug 2021 20:14:17 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 24A4E61360 for ; Tue, 24 Aug 2021 20:14:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 24A4E61360 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id D393C81D5F; Tue, 24 Aug 2021 20:14:16 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nDPqpeO0P1za; Tue, 24 Aug 2021 20:14:13 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id 663E481D5A; Tue, 24 Aug 2021 20:14:12 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 34DD1C001A; Tue, 24 Aug 2021 20:14:12 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9B17FC000E for ; Tue, 24 Aug 2021 20:14:10 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 88F3F42516 for ; Tue, 24 Aug 2021 20:14:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id r8IXyYCkhkxV for ; Tue, 24 Aug 2021 20:14:07 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by smtp4.osuosl.org (Postfix) with ESMTPS id D83A342502 for ; Tue, 24 Aug 2021 20:14:06 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10086"; a="204591559" X-IronPort-AV: E=Sophos;i="5.84,348,1620716400"; d="scan'208";a="204591559" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2021 13:14:05 -0700 X-IronPort-AV: E=Sophos;i="5.84,348,1620716400"; d="scan'208";a="526813111" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.119.65]) ([10.209.119.65]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2021 13:14:03 -0700 Subject: Re: [PATCH v4 11/15] pci: Add pci_iomap_shared{,_range} To: Bjorn Helgaas References: <20210824185541.GA3485816@bjorn-Precision-5520> From: Andi Kleen Message-ID: Date: Tue, 24 Aug 2021 13:14:02 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210824185541.GA3485816@bjorn-Precision-5520> Content-Language: en-US Cc: "Kuppuswamy, Sathyanarayanan" , Kuppuswamy Sathyanarayanan , "Michael S. Tsirkin" , Peter Zijlstra , Linux PCI , linux-mips@vger.kernel.org, James E J Bottomley , Dave Hansen , Peter H Anvin , sparclinux@vger.kernel.org, Rajat Jain , Thomas Gleixner , linux-arch , Jonathan Corbet , Helge Deller , X86 ML , Ingo Molnar , Arnd Bergmann , Tony Luck , Borislav Petkov , Andy Lutomirski , Bjorn Helgaas , Dan Williams , virtualization@lists.linux-foundation.org, Richard Henderson , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, Sean Christopherson , Linux Doc Mailing List , Linux Kernel Mailing List , linux-alpha@vger.kernel.org, "David S . Miller" , Kirill Shutemov X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" On 8/24/2021 11:55 AM, Bjorn Helgaas wrote: > [+cc Rajat; I still don't know what "shared memory with a hypervisor > in a confidential guest" means, A confidential guest is a guest which uses memory encryption to isolate itself from the host. It doesn't trust the host. But it still needs to communicate with the host for IO, so it has some special memory areas that are explicitly marked shared. These are used to do IO with the host. All their usage needs to be carefully hardened to avoid any security attacks on the guest, that's why we want to limit this interaction only to a small set of hardened drivers. For MMIO, the set is currently only virtio and MSI-X. -Andi _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH v4 11/15] pci: Add pci_iomap_shared{,_range} Date: Tue, 24 Aug 2021 13:14:02 -0700 Message-ID: References: <20210824185541.GA3485816@bjorn-Precision-5520> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20210824185541.GA3485816@bjorn-Precision-5520> Content-Language: en-US List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Bjorn Helgaas Cc: "Michael S. Tsirkin" , Dan Williams , "Kuppuswamy, Sathyanarayanan" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , Bjorn Helgaas , Richard Henderson , Thomas Bogendoerfer , James E J Bottomley , Helge Deller , "David S . Miller" , Arnd Bergmann , Jonathan Corbet , Peter H Anvin , Dave Hansen , Tony Luck On 8/24/2021 11:55 AM, Bjorn Helgaas wrote: > [+cc Rajat; I still don't know what "shared memory with a hypervisor > in a confidential guest" means, A confidential guest is a guest which uses memory encryption to isolate itself from the host. It doesn't trust the host. But it still needs to communicate with the host for IO, so it has some special memory areas that are explicitly marked shared. These are used to do IO with the host. All their usage needs to be carefully hardened to avoid any security attacks on the guest, that's why we want to limit this interaction only to a small set of hardened drivers. For MMIO, the set is currently only virtio and MSI-X. -Andi