Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 23 Sep 2022 09:15:42 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Baolu Lu <baolu.lu@linux.intel.com>
Cc:     Joerg Roedel <joro@8bytes.org>,
        Christoph Hellwig <hch@infradead.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Eric Auger <eric.auger@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>,
        Jacob jun Pan <jacob.jun.pan@intel.com>,
        Zhangfei Gao <zhangfei.gao@linaro.org>,
        Zhu Tony <tony.zhu@intel.com>, iommu@lists.linux.dev,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v13 07/13] iommu/vt-d: Add SVA domain support
Message-ID: <Yy2jbsaXuoxgR+fj@nvidia.com>
References: <20220906124458.46461-1-baolu.lu@linux.intel.com>
 <20220906124458.46461-8-baolu.lu@linux.intel.com>
 <YyyECCbmfsaDpDgJ@nvidia.com>
 <075278e0-77ce-2361-8ded-6cd6bb20216f@linux.intel.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <075278e0-77ce-2361-8ded-6cd6bb20216f@linux.intel.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ohaoaSdEftPn05VkD9XetILYtFDEvx3CL1ttxCAWSBrgcj7ONU3HM2WCxOQ1?=
 =?us-ascii?Q?0bS1U8J66lj9kKRxI5paVQZN3YanovWIrj8VBRv9kEitjbhFVeiqpldCyjTb?=
 =?us-ascii?Q?LR42/YzOatAHGlStxlhSvBiuH2dRCBnvlkMOIihiHDjWuez98Ju/Zb7WskvL?=
 =?us-ascii?Q?jDqR7DbQMgTZFhPlSba+rFIP9tSztpO8JDQOIa/2FpRRHK1L1qYUZmrCCuKU?=
 =?us-ascii?Q?oLTLq5uvRhJHrWI7NxsSbuvkouibvtzh3yoUqsStOhrpTHjmqnQE/un6sgJQ?=
 =?us-ascii?Q?s+KXCjjZ196VARq+4YQnMD+Qpt4w0YAvfYhT67HBF45UzgS312OjtlT+bEB4?=
 =?us-ascii?Q?EHYJzPQMunylEX/CgaFef2//J4bln93lDvyYoyfH5nmtURO42mOKQNWhZrgs?=
 =?us-ascii?Q?s22IUaJPDS2wN6dkNW5/uzvCOa2j4LL5Gg4Ho94grNkOCsAsEeEcJRxm7ISw?=
 =?us-ascii?Q?sHmczJXOiBq1nGK2d0jIOiII+WzFyo6t5yI27EC5M5WTlwxTtwZECULyRhx1?=
 =?us-ascii?Q?2/0EGk8AqtAnT9gYRESGlcPASYzfp7zQvrGfu5xuvA3vwoWb96mpqxawNX0L?=
 =?us-ascii?Q?4QaZLjZGqAz6oiR1Gx1pmTQDvTAkfsiDbsai2Cc3vvtdKk0Ww5vBFGt93roH?=
 =?us-ascii?Q?ortEsf8Bs3KmQ9qdEMqXk4BFAgu87As2z+GxVn3x5jAR3aGTHG9U8wCk0PRM?=
 =?us-ascii?Q?C4JemfldYQ1BybjG4DunXp11RFamIMel0w/830ngDTHO7PujMs6ZhzJzft2+?=
 =?us-ascii?Q?WmpNWAf40vHKQ5Se5PZtrnnrtr7Vj8nEgg+yoXRzmgr7k3NITzKgTqlmDRc6?=
 =?us-ascii?Q?sChzHC/qTit9FhsJPBogkf/SlYVt0gRYY7BPSy7uNFqdeqm4wdux43sAFn2l?=
 =?us-ascii?Q?N359/mH75Am+94cOQLwUbx3Vb9U2zKM7JjWn5U+u6sYluaUrCV1MmC9lni9h?=
 =?us-ascii?Q?fMwYP6MhT2maxy68MTChXuzjIbYlgcXBRROBf4VpDtlo34d0+mFGny1GCyv6?=
 =?us-ascii?Q?i+cGxFIsMGUavgQk36oFp88w0yUQUD0O3y2FhVNrKOBs1KmQv6189qirSUk1?=
 =?us-ascii?Q?6oRerXsnsY/o1dp7m6mtIK7Rxxt5H6ryBbn3eWqywsLSQaF/Fvn7TsA1zX4O?=
 =?us-ascii?Q?S/4z5rDURvimfEoHOoQj8hxlSFCdVIbARI/DG2q7z3EEfjp6ShxQFgdEFhcn?=
 =?us-ascii?Q?ScooshtMV3nXCXfna1gUDanyrTX+Vv1ogDdI2UQ3T2tlDygij/Odzu+qYENR?=
 =?us-ascii?Q?uK+AXfG6GR8IhpADbD33xRp8KTcbw1hJ4fYDkpPkDdRQsTuiGYHnKlLyvq/5?=
 =?us-ascii?Q?7Na854/yjr3Sohrik4h/9mPs9We8OGNu0E6xYPo4UtolfizBeR5y4s7WiSVA?=
 =?us-ascii?Q?bcfbFySNlsubJtiR1veZWGReouQqV5E+jVJpXqV0Z7TEIIOaXWnH0MnrxTtB?=
 =?us-ascii?Q?Kp/vR+P97aRHrDlazUB38l1gfD4yvPmTatVSzHcZhGU5iAsli0mPH7MCQr+0?=
 =?us-ascii?Q?enf0SN9TW1jJdCGFhB6su8qmRi6A3s10UvztgYR8NQojnUC1lbmgbhjuiI8M?=
 =?us-ascii?Q?xUxPgK3xeR9XoSUWgcEyXWaQefPTmU6jv/Ukb7MI?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 0b171f8c-66da-4b2d-5f82-08da9d5d5682
X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Sep 2022 12:15:44.1824
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: Aagg+O/cPKOCT/9/B+VLWI2uYma3Eyr6dqW48BcCYlxdzJ3UiaYLhDGX/HdFTHxT
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR12MB6340
X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE
        autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Sep 23, 2022 at 10:21:51AM +0800, Baolu Lu wrote:

> At the beginning of this project, I wanted to consolidate the mm
> notifications into the core. However, ARM SMMUv3 and Intel handle the mm
> notifications a little differently. Then I decided to do this work
> separately from the current series.

It doesn't look really different..

The SVA iommu domain needs two new ops triggered by the notifier:

 - 'stop using the mm, subsitute a blocking domain' tied to release
 - Cache invalidate a range, maybe this is just iotlb_sync_map()

And we could even think about the first as the core code literally
attaching a dummy blocking domain and releasing the SVA domain. There
is no reason we need to have every driver do this tricky bit of
lifecycle management.

Jason