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 4D03EC43331 for ; Tue, 24 Mar 2020 01:42:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C4BA20722 for ; Tue, 24 Mar 2020 01:42:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727194AbgCXBma (ORCPT ); Mon, 23 Mar 2020 21:42:30 -0400 Received: from mga06.intel.com ([134.134.136.31]:34433 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727053AbgCXBm3 (ORCPT ); Mon, 23 Mar 2020 21:42:29 -0400 IronPort-SDR: JBgzrgoK7kffK/l+cwFL+d7SaUOn82L3nfteoI5LxGg2pl+/bHN9EyQ4Z+mGy2iOCAnnhPJVE9 XTl5HhWqlFmw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2020 18:42:28 -0700 IronPort-SDR: LefSmsp92s2IYF/PXnr6Ipuk/XOB1mRv7a3IU3qijkzj/XlZb1QGzvYjNjxIF9jCqaFVGqPRmz mqkp44TBM4QA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,298,1580803200"; d="scan'208";a="264976626" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.254.208.83]) ([10.254.208.83]) by orsmga002.jf.intel.com with ESMTP; 23 Mar 2020 18:42:22 -0700 Cc: baolu.lu@linux.intel.com, Jacob Pan , iommu@lists.linux-foundation.org, LKML , Joerg Roedel , David Woodhouse , Yi Liu , "Tian, Kevin" , Jean-Philippe Brucker , Eric Auger , Dave Jiang , "Lu, Baolu" Subject: Re: [PATCH 2/2] iommu/vt-d: Replace intel SVM APIs with generic SVA APIs To: "Raj, Ashok" , Jean-Philippe Brucker References: <1582586797-61697-1-git-send-email-jacob.jun.pan@linux.intel.com> <1582586797-61697-4-git-send-email-jacob.jun.pan@linux.intel.com> <20200320092955.GA1702630@myrica> <20200323230113.GA84386@otc-nc-03> From: Lu Baolu Message-ID: <6cc2f1ea-5a7d-eeab-b50c-5b464098de6b@linux.intel.com> Date: Tue, 24 Mar 2020 09:42:20 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200323230113.GA84386@otc-nc-03> 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 2020/3/24 7:01, Raj, Ashok wrote: > Hi Jean > > On Fri, Mar 20, 2020 at 10:29:55AM +0100, Jean-Philippe Brucker wrote: >>> +#define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva) >>> +struct iommu_sva * >>> +intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata) >>> +{ >>> + struct iommu_sva *sva = ERR_PTR(-EINVAL); >>> + struct intel_svm_dev *sdev = NULL; >>> + int flags = 0; >>> + int ret; >>> + >>> + /* >>> + * TODO: Consolidate with generic iommu-sva bind after it is merged. >>> + * It will require shared SVM data structures, i.e. combine io_mm >>> + * and intel_svm etc. >>> + */ >>> + if (drvdata) >>> + flags = *(int *)drvdata; >> >> drvdata is more for storing device driver contexts that can be passed to >> iommu_sva_ops, but I get that this is temporary. >> >> As usual I'm dreading supervisor mode making it into the common API. What >> are your plans regarding SUPERVISOR_MODE and PRIVATE_PASID flags? The >> previous discussion on the subject [1] had me hoping that you could >> replace supervisor mode with normal mappings (auxiliary domains?) >> I'm less worried about PRIVATE_PASID, it would just add complexity into > > We don't seem to have an immediate need for PRIVATE_PASID. There are some talks > about potential usages, but nothing concrete. I think it might be good to > get rid of it now and add when we really need. > > For SUPERVISOR_MODE, the idea is to have aux domain. Baolu is working on > something to replace. Certainly the entire kernel address is opening up > the whole kimono.. so we are looking at dynamically creating mappings on demand. > It might take some of the benefits of SVA in general with no need to create > mappings, but for security somebody has to pay the price :-) My thought is to reuse below aux-domain API. int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev) Currently, it asks the vendor iommu driver to allocate a PASID and bind the domain with it. We can change it to allow the caller to pass in an existing supervisor PASID. int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev, int *pasid) In the vendor iommu driver, if (*pasid == INVALID_IOASID), it will allocate a pasid (the same as current behavior); otherwise, attach the domain with the pass-in pasid. Best regards, baolu