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Tue, 7 Mar 2023 16:33:12 +0000 Received: from IA1PR11MB6097.namprd11.prod.outlook.com ([fe80::4381:c78f:bb87:3a37]) by IA1PR11MB6097.namprd11.prod.outlook.com ([fe80::4381:c78f:bb87:3a37%6]) with mapi id 15.20.6156.029; Tue, 7 Mar 2023 16:33:11 +0000 Message-ID: <156f9e28-e7d2-b443-1aa5-1f5447cb9bbd@intel.com> Date: Tue, 7 Mar 2023 08:33:07 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.11.0 Subject: Re: [PATCH v2 08/16] iommu: define and export iommu_access_remote_vm() Content-Language: en-US To: Jean-Philippe Brucker , Jacob Pan CC: Vinod Koul , Dave Jiang , , linux-kernel , Alistair Popple , Joerg Roedel , "Will Deacon" , Robin Murphy , "Lorenzo Stoakes" , Christoph Hellwig , References: <20230306163138.587484-1-fenghua.yu@intel.com> <20230306163138.587484-9-fenghua.yu@intel.com> <20230307084058.GA1330745@myrica> From: Fenghua Yu In-Reply-To: <20230307084058.GA1330745@myrica> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BYAPR02CA0001.namprd02.prod.outlook.com (2603:10b6:a02:ee::14) To IA1PR11MB6097.namprd11.prod.outlook.com (2603:10b6:208:3d7::17) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA1PR11MB6097:EE_|SJ1PR11MB6202:EE_ X-MS-Office365-Filtering-Correlation-Id: 86c9d617-f33d-495a-452d-08db1f29a475 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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This change removes >> patch 8 and 9 in v1 (Alistair Popple) >> >> drivers/iommu/iommu-sva.c | 35 +++++++++++++++++++++++++++++++++++ >> include/linux/iommu.h | 9 +++++++++ >> 2 files changed, 44 insertions(+) >> >> diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c >> index 24bf9b2b58aa..1d7a0aee58f7 100644 >> --- a/drivers/iommu/iommu-sva.c >> +++ b/drivers/iommu/iommu-sva.c >> @@ -71,6 +71,41 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid) >> } >> EXPORT_SYMBOL_GPL(iommu_sva_find); >> >> +/** >> + * iommu_access_remote_vm - access another process' address space by PASID >> + * @pasid: Process Address Space ID assigned to the mm >> + * @addr: start address to access >> + * @buf: source or destination buffer >> + * @len: number of bytes to transfer >> + * @gup_flags: flags modifying lookup behaviour >> + * >> + * Another process' address space is found by PASID. A reference on @mm >> + * is taken and released inside the function. >> + * >> + * Return: number of bytes copied from source to destination. >> + */ >> +int iommu_access_remote_vm(ioasid_t pasid, unsigned long addr, void *buf, >> + int len, unsigned int gup_flags) >> +{ >> + struct mm_struct *mm; >> + int copied; >> + >> + mm = iommu_sva_find(pasid); > > The ability to find a mm by PASID is being removed, see > https://lore.kernel.org/linux-iommu/20230301235646.2692846-4-jacob.jun.pan@linux.intel.com/ > Thank you very much for pointing out this. I talked to Jacob just now. He will keep iommu_sva_find() function in his next version because this patch is still using the function. He agrees that I can still call iommu_sva_find() in this patch. -Fenghua