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=-2.2 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 03F53C3F2D1 for ; Wed, 4 Mar 2020 17:34:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5E3421D56 for ; Wed, 4 Mar 2020 17:34:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727528AbgCDRer (ORCPT ); Wed, 4 Mar 2020 12:34:47 -0500 Received: from 8bytes.org ([81.169.241.247]:50024 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727308AbgCDRer (ORCPT ); Wed, 4 Mar 2020 12:34:47 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id EE5B22E2; Wed, 4 Mar 2020 18:34:45 +0100 (CET) Date: Wed, 4 Mar 2020 18:34:42 +0100 From: Joerg Roedel To: Jacob Pan Cc: "Michael S. Tsirkin" , Jean-Philippe Brucker , kevin.tian@intel.com, linux-pci@vger.kernel.org, jasowang@redhat.com, virtualization@lists.linux-foundation.org, iommu@lists.linux-foundation.org, sebastien.boeuf@intel.com, bhelgaas@google.com, robin.murphy@arm.com Subject: Re: [PATCH v2 1/3] iommu/virtio: Add topology description to virtio-iommu config space Message-ID: <20200304173441.GB3315@8bytes.org> References: <20200228172537.377327-1-jean-philippe@linaro.org> <20200228172537.377327-2-jean-philippe@linaro.org> <20200302161611.GD7829@8bytes.org> <9004f814-2f7c-9024-3465-6f9661b97b7a@redhat.com> <20200303130155.GA13185@8bytes.org> <20200303084753-mutt-send-email-mst@kernel.org> <20200303155318.GA3954@8bytes.org> <20200303105523-mutt-send-email-mst@kernel.org> <20200304133707.GB4177@8bytes.org> <20200304074854.3ea958a1@jacob-XPS-13-9365> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200304074854.3ea958a1@jacob-XPS-13-9365> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Mar 04, 2020 at 07:48:54AM -0800, Jacob Pan wrote: > For emulated VT-d IOMMU, GIOVA can also be build as first level page > tables then pass to the host IOMMU to bind. There is no need to shadow > in this case, pIOMMU will do nested translation and walk guest page > tables. Right, but that requires hardware support. A pure software emulation of VT-d requires the full shadow of the guest io-page-table. > I thought we have the universal device properties to abstract DT and > ACPI (via _DSD). Is that an option? I don't know whether this was considered, Jean-Philippe? Regards, Joerg