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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 7BA34C3A5A1 for ; Wed, 28 Aug 2019 06:25:54 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 513382070B for ; Wed, 28 Aug 2019 06:25:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 513382070B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33070 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2rOz-0001hp-DK for qemu-devel@archiver.kernel.org; Wed, 28 Aug 2019 02:25:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41536) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2rO7-00015U-5K for qemu-devel@nongnu.org; Wed, 28 Aug 2019 02:25:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i2rO6-0004ax-8L for qemu-devel@nongnu.org; Wed, 28 Aug 2019 02:24:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49656) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i2rO4-0004Xf-47; Wed, 28 Aug 2019 02:24:56 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 282FD1089041; Wed, 28 Aug 2019 06:24:55 +0000 (UTC) Received: from [10.36.116.105] (ovpn-116-105.ams2.redhat.com [10.36.116.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B3F26600D1; Wed, 28 Aug 2019 06:24:48 +0000 (UTC) To: Peter Maydell References: <20190822172350.12008-1-eric.auger@redhat.com> <20190822172350.12008-3-eric.auger@redhat.com> From: Auger Eric Message-ID: Date: Wed, 28 Aug 2019 08:24:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.64]); Wed, 28 Aug 2019 06:24:55 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v4 2/5] memory: Add IOMMU_ATTR_HW_NESTED_PAGING IOMMU memory region attribute X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: QEMU Developers , Peter Xu , Alex Williamson , qemu-arm , Paolo Bonzini , Eric Auger Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Peter, On 8/27/19 6:19 PM, Peter Maydell wrote: > On Thu, 22 Aug 2019 at 18:24, Eric Auger wrote: >> >> We introduce a new IOMMU Memory Region attribute, >> IOMMU_ATTR_HW_NESTED_PAGING that tells whether the virtual >> IOMMU relies on physical IOMMU HW nested paging capability >> when protecting host assigned devices. > > I'm still not really happy with the name of this attribute. > "IOMMU_ATTR_HW_NESTED_PAGING" sounds like it ought to mean > "true if this IOMMU supports/is using hardware nested paging". What > your commit message suggests it means is "true if this IOMMU > *needs* hardware nested paging", but there's no NEEDS in the > attribute name. OK I will respin and add "_NEED_". Thanks Eric > >> Current Intel virtual IOMMU device supports "Caching >> Mode" and does not require 2 stages at physical level to be >> integrated with VFIO. However SMMUv3 does not implement such >> "caching mode" and requires to use HW nested paging. >> >> As such SMMUv3 is the first IOMMU device to advertise this >> attribute. >> >> Signed-off-by: Eric Auger > > The code changes look good to me though. > > thanks > -- PMM >