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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 69E40C43387 for ; Fri, 11 Jan 2019 09:15:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4387D20870 for ; Fri, 11 Jan 2019 09:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730210AbfAKJPE (ORCPT ); Fri, 11 Jan 2019 04:15:04 -0500 Received: from 8bytes.org ([81.169.241.247]:56744 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725601AbfAKJPE (ORCPT ); Fri, 11 Jan 2019 04:15:04 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id ABABC3A2; Fri, 11 Jan 2019 10:15:02 +0100 (CET) Date: Fri, 11 Jan 2019 10:15:02 +0100 From: Joerg Roedel To: Jason Wang Cc: "Michael S . Tsirkin" , Konrad Rzeszutek Wilk , Jens Axboe , virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jfehlig@suse.com, jon.grimm@amd.com, brijesh.singh@amd.com, hch@lst.de Subject: Re: [PATCH 0/3] Fix virtio-blk issue with SWIOTLB Message-ID: <20190111091502.GC5825@8bytes.org> References: <20190110134433.15672-1-joro@8bytes.org> <5ae1341e-62ec-0478-552b-259eabf9fb17@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5ae1341e-62ec-0478-552b-259eabf9fb17@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Jan 11, 2019 at 11:29:31AM +0800, Jason Wang wrote: > Just wonder if my understanding is correct IOMMU_PLATFORM must be set for > all virtio devices under AMD-SEV guests? Yes, that is correct. Emulated DMA can only happen on the SWIOTLB aperture, because that memory is not encrypted. The guest bounces the data then to its encrypted memory. Regards, Joerg