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BLAPR10MB4835.namprd10.prod.outlook.com (2603:10b6:208:331::11) by SJ1PR10MB5978.namprd10.prod.outlook.com (2603:10b6:a03:45f::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6521.24; Tue, 27 Jun 2023 10:57:03 +0000 Received: from BLAPR10MB4835.namprd10.prod.outlook.com ([fe80::f7ba:4a04:3f37:6d0f]) by BLAPR10MB4835.namprd10.prod.outlook.com ([fe80::f7ba:4a04:3f37:6d0f%5]) with mapi id 15.20.6521.026; Tue, 27 Jun 2023 10:57:03 +0000 Message-ID: Date: Tue, 27 Jun 2023 11:56:57 +0100 Subject: Re: [PATCH v3 3/3] vfio/migration: vfio/migration: Refactor and fix print of "Migration disabled" Content-Language: en-US To: "Duan, Zhenzhong" , Avihai Horon Cc: "alex.williamson@redhat.com" , "clg@redhat.com" , "Peng, Chao P" , "qemu-devel@nongnu.org" References: <20230621080204.420723-1-zhenzhong.duan@intel.com> <20230621080204.420723-4-zhenzhong.duan@intel.com> <3afe5106-414e-5a3d-4a15-3992f80fac5b@oracle.com> From: Joao Martins In-Reply-To: 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definitions=main-2306270100 X-Proofpoint-GUID: U9yb4n685AnbJs4Ty8wgKWK_x4oXYSdI X-Proofpoint-ORIG-GUID: U9yb4n685AnbJs4Ty8wgKWK_x4oXYSdI Received-SPF: pass client-ip=205.220.177.32; envelope-from=joao.m.martins@oracle.com; helo=mx0b-00069f02.pphosted.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 27/06/2023 03:55, Duan, Zhenzhong wrote: >> I guess it makes sense -- the thing that was tieing him was the global migration >> blocker, which is now consolidated into the main migration blocker. >> >> My vIOMMU series will relax this condition yes (still same per-device scope). >> And I will need to check the maximum IOVA in the vIOMMU. But it's new code >> I can adjust and Zhenzhong shouldn't worry about the vIOMMU future stuff > A bit confused, you agreed to move vfio_block_giommu_migration into migration.c > >> but I don't expect to influence location, say if it gets moved into migration.c > and final decision is no move for influencing location reason? Do I misunderstand? Sorry for the confusion. The thing is that I will need 'similar code' to test if a vIOMMU is enabled or not. The reason being that dirty tracking will need this to understand what to track meaning to decide whether we track the whole address space or just the linear map[0]. And all that code is in common, not migration.c and where I use it will have to look at all address spaces (because dirty tracking is started for all devices, so there's no vbasedev to look at). Eventually after the vIOMMU stuff, the migration blocker condition will look more or less like this: return (!vfio_viommu_preset(vbasedev) || (vfio_viommu_preset(vbasedev) && !vfio_viommu_get_max_iova(&max))) Whereby vfio_viommu_preset(vbasedev) is what you currently call vfio_block_giommu_migration(vbasedev) in current patch. So perhaps I would say to leave it in common.c and rename it to vfio_viommu_preset(vbasedev) with a comment on top for /* Block migration with a vIOMMU */ Then when the time comes I can introduce in my vIOMMU series a vfio_viommu_possible() [or some other name] when starting dirty tracking which looks all VFIOAddressSpaces and reuses your vfio_viommu_preset(vbasedev). This should cover current and future needs, without going to great extents beyond the purpose of this patch? [0] https://lore.kernel.org/qemu-devel/20230622214845.3980-13-joao.m.martins@oracle.com/#iZ31hw:vfio:common.c