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 DDDF8C2D0C8 for ; Sat, 21 Dec 2019 02:52:42 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 A4C8420716 for ; Sat, 21 Dec 2019 02:52:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4C8420716 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=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 9DF1487440; Sat, 21 Dec 2019 02:52:41 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fCYHXStTMoBI; Sat, 21 Dec 2019 02:52:39 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 5A90F87454; Sat, 21 Dec 2019 02:52:39 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4331CC1796; Sat, 21 Dec 2019 02:52:39 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 494B9C077D for ; Sat, 21 Dec 2019 02:52:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 337EC87E75 for ; Sat, 21 Dec 2019 02:52:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Aqs6J3xUlrjf for ; Sat, 21 Dec 2019 02:52:37 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by hemlock.osuosl.org (Postfix) with ESMTPS id 69AF287E5E for ; Sat, 21 Dec 2019 02:52:37 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Dec 2019 18:52:37 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,338,1571727600"; d="scan'208";a="228782618" Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by orsmga002.jf.intel.com with ESMTP; 20 Dec 2019 18:52:34 -0800 Subject: Re: [PATCH v4 0/7] Use 1st-level for IOVA translation To: "Liu, Yi L" , Joerg Roedel , David Woodhouse , Alex Williamson References: <20191219031634.15168-1-baolu.lu@linux.intel.com> From: Lu Baolu Message-ID: Date: Sat, 21 Dec 2019 10:51:38 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: "Tian, Kevin" , "Raj, Ashok" , "kvm@vger.kernel.org" , "Kumar, Sanjay K" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "Sun, Yi Y" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support 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: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Yi, Thanks for the comments. On 12/20/19 7:50 PM, Liu, Yi L wrote: > Hi Baolu, > > In a brief, this version is pretty good to me. However, I still want > to have the following checks to see if anything missed. Wish it > helps. > > 1) would using IOVA over FLPT default on? > My opinion is that before we have got gIOVA nested translation > done for passthru devices, we should make this feature as off. No worry. IOVA over first level is a sub-feature of scalable mode. Currently, scalable mode is default off and we won't switch it on until all features are done. > > 2) the domain->agaw is somehow calculated according to the > capabilities related to second level page table. As we are moving > IOVA to FLPT, I'd suggest to calculate domain->agaw with the > translation modes FLPT supports (e.g. 4 level and 5 level) We merged first level and second level, hence the domain->agaw should be selected for both. The only shortcoming of this is that it doesn't support a 3-only second level in scalable mode. But I don't think we have any chances to see such hardware. > > 3) Per VT-d spec, FLPT has canonical requirement to the input > addresses. So I'd suggest to add some enhance regards to it. > Please refer to chapter 3.6 :-). Yes. Good catch! We should manipulate the page table entry according to this requirement. > > 3.6 First-Level Translation > First-level translation restricts the input-address to a canonical address (i.e., address bits 63:N have > the same value as address bit [N-1], where N is 48-bits with 4-level paging and 57-bits with 5-level > paging). Requests subject to first-level translation by remapping hardware are subject to canonical > address checking as a pre-condition for first-level translation, and a violation is treated as a > translation-fault. > > Regards, > Yi Liu Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu