Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) client-ip=2620:137:e000::3:4;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 216.228.117.160 as permitted sender) receiver=protection.outlook.com;
 client-ip=216.228.117.160; helo=mail.nvidia.com; pr=C
Date:   Tue, 5 Dec 2023 09:33:30 -0800
From:   Nicolin Chen <nicolinc@nvidia.com>
To:     Jason Gunthorpe <jgg@nvidia.com>
CC:     "Tian, Kevin" <kevin.tian@intel.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>,
        "joro@8bytes.org" <joro@8bytes.org>,
        "alex.williamson@redhat.com" <alex.williamson@redhat.com>,
        "robin.murphy@arm.com" <robin.murphy@arm.com>,
        "baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
        "cohuck@redhat.com" <cohuck@redhat.com>,
        "eric.auger@redhat.com" <eric.auger@redhat.com>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "mjrosato@linux.ibm.com" <mjrosato@linux.ibm.com>,
        "chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
        "yi.y.sun@linux.intel.com" <yi.y.sun@linux.intel.com>,
        "peterx@redhat.com" <peterx@redhat.com>,
        "jasowang@redhat.com" <jasowang@redhat.com>,
        "shameerali.kolothum.thodi@huawei.com" 
        <shameerali.kolothum.thodi@huawei.com>,
        "lulu@redhat.com" <lulu@redhat.com>,
        "suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
        "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>,
        "Duan, Zhenzhong" <zhenzhong.duan@intel.com>,
        "joao.m.martins@oracle.com" <joao.m.martins@oracle.com>,
        "Zeng, Xin" <xin.zeng@intel.com>,
        "Zhao, Yan Y" <yan.y.zhao@intel.com>
Subject: Re: [PATCH v6 2/6] iommufd: Add IOMMU_HWPT_INVALIDATE
Message-ID: <ZW9e6hxyDmkK8bfe@Asurada-Nvidia>
References: <ZWe2PvatTkkyNCY5@Asurada-Nvidia>
 <20231130000816.GB1389974@nvidia.com>
 <ZWjzcEAAg8ptVH4A@Asurada-Nvidia>
 <20231201004523.GJ1389974@nvidia.com>
 <ZWlhLk3JVwX0hRt/@Asurada-Nvidia>
 <20231201125538.GK1389974@nvidia.com>
 <ZWo6z59tnmS8F2V7@Asurada-Nvidia>
 <20231201204340.GA1493156@nvidia.com>
 <ZWpaTD9dVge+suyv@Asurada-Nvidia>
 <20231204144850.GC1493156@nvidia.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20231204144850.GC1493156@nvidia.com>
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Dec 2023 17:33:50.9409
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: cb559ea3-8dac-4ae7-3f91-08dbf5b85885
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: SA2PEPF000015C9.namprd03.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5297
X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on howler.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Tue, 05 Dec 2023 09:34:21 -0800 (PST)

On Mon, Dec 04, 2023 at 10:48:50AM -0400, Jason Gunthorpe wrote:
 
> > Or am I missing some point here?
> 
> It sounds Ok, we just have to understand what userspace should be
> doing and how much of this the kernel should implement.
> 
> It seems to me that the error code should return the gerror and the
> req_num should indicate the halted cons. The vmm should relay both
> into the virtual registers.

I see your concern. I will take a closer look and see if we can
add to the initial version of arm_smmu_cache_invalidate_user().
Otherwise, we can add later.

Btw, VT-d seems to want the error_code and reports in the VT-d
specific invalidate entry structure, as Kevin and Yi had that
discussion in the other side of the thread.

Thanks
Nicolin