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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 692B7C83004 for ; Wed, 29 Apr 2020 10:56:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42C092072A for ; Wed, 29 Apr 2020 10:56:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726746AbgD2K41 (ORCPT ); Wed, 29 Apr 2020 06:56:27 -0400 Received: from david.siemens.de ([192.35.17.14]:49909 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726556AbgD2K41 (ORCPT ); Wed, 29 Apr 2020 06:56:27 -0400 Received: from mail2.sbs.de (mail2.sbs.de [192.129.41.66]) by david.siemens.de (8.15.2/8.15.2) with ESMTPS id 03TAtvj5019413 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 29 Apr 2020 12:55:57 +0200 Received: from [167.87.241.229] ([167.87.241.229]) by mail2.sbs.de (8.15.2/8.15.2) with ESMTP id 03TAtuRB023743; Wed, 29 Apr 2020 12:55:56 +0200 Subject: Re: [virtio-dev] Re: [PATCH 5/5] virtio: Add bounce DMA ops To: "Michael S. Tsirkin" Cc: Srivatsa Vaddagiri , Lu Baolu , tsoni@codeaurora.org, virtio-dev@lists.oasis-open.org, konrad.wilk@oracle.com, jasowang@redhat.com, christoffer.dall@arm.com, virtualization@lists.linux-foundation.org, alex.bennee@linaro.org, iommu@lists.linux-foundation.org, stefano.stabellini@xilinx.com, will@kernel.org, linux-kernel@vger.kernel.org, pratikp@codeaurora.org References: <20200428163448-mutt-send-email-mst@kernel.org> <275eba4b-dd35-aa95-b2e3-9c5cbf7c6d71@linux.intel.com> <20200429004531-mutt-send-email-mst@kernel.org> <20200429023842-mutt-send-email-mst@kernel.org> <20200429094410.GD5097@quicinc.com> <20200429055125-mutt-send-email-mst@kernel.org> <20200429100953.GE5097@quicinc.com> <20200429061621-mutt-send-email-mst@kernel.org> <20200429064458-mutt-send-email-mst@kernel.org> From: Jan Kiszka Message-ID: <303ace66-950c-955d-d750-74de5054788a@siemens.com> Date: Wed, 29 Apr 2020 12:55:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200429064458-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29.04.20 12:45, Michael S. Tsirkin wrote: > On Wed, Apr 29, 2020 at 12:26:43PM +0200, Jan Kiszka wrote: >> On 29.04.20 12:20, Michael S. Tsirkin wrote: >>> On Wed, Apr 29, 2020 at 03:39:53PM +0530, Srivatsa Vaddagiri wrote: >>>> That would still not work I think where swiotlb is used for pass-thr devices >>>> (when private memory is fine) as well as virtio devices (when shared memory is >>>> required). >>> >>> So that is a separate question. When there are multiple untrusted >>> devices, at the moment it looks like a single bounce buffer is used. >>> >>> Which to me seems like a security problem, I think we should protect >>> untrusted devices from each other. >>> >> >> Definitely. That's the model we have for ivshmem-virtio as well. >> >> Jan > > Want to try implementing that? > The desire is definitely there, currently "just" not the time. Jan -- Siemens AG, Corporate Technology, CT RDA IOT SES-DE Corporate Competence Center Embedded Linux