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Subject: Re: [PATCH v4 01/17] iommu: Add hwpt_type with user_data for
 domain_alloc_user op
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From:   Yi Liu <yi.l.liu@intel.com>
To:     "Tian, Kevin" <kevin.tian@intel.com>,
        "joro@8bytes.org" <joro@8bytes.org>,
        "alex.williamson@redhat.com" <alex.williamson@redhat.com>,
        "jgg@nvidia.com" <jgg@nvidia.com>,
        "robin.murphy@arm.com" <robin.murphy@arm.com>,
        "baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>
CC:     "cohuck@redhat.com" <cohuck@redhat.com>,
        "eric.auger@redhat.com" <eric.auger@redhat.com>,
        "nicolinc@nvidia.com" <nicolinc@nvidia.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>,
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        "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>,
        "Martins, Joao" <joao.m.martins@oracle.com>
References: <20230921075138.124099-1-yi.l.liu@intel.com>
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On 2023/10/12 17:12, Yi Liu wrote:
> On 2023/9/26 14:56, Tian, Kevin wrote:
>>> From: Yi Liu <yi.l.liu@intel.com>
>>> Sent: Thursday, September 21, 2023 3:51 PM
>>> +
>>> +/**
>>> + * iommu_copy_user_data - Copy iommu driver specific user space data
>>> + * @dst_data: Pointer to an iommu driver specific user data that is 
>>> defined
>>> in
>>> + *            include/uapi/linux/iommufd.h
>>> + * @src_data: Pointer to a struct iommu_user_data for user space data info
>>> + * @data_len: Length of current user data structure, i.e. sizeof(struct 
>>> _dst)
>>> + * @min_len: Initial length of user data structure for backward 
>>> compatibility.
>>> + *           This should be offsetofend using the last member in the 
>>> user data
>>> + *           struct that was initially added to 
>>> include/uapi/linux/iommufd.h
>>> + */
>>> +static inline int iommu_copy_user_data(void *dst_data,
>>> +                       const struct iommu_user_data *src_data,
>>> +                       size_t data_len, size_t min_len)
>>
>> iommu_copy_struct_from_user()?
>>
>> btw given the confusion raised on how this would be used is it clearer
>> to move it to the patch together with the 1st user?
> 
> sure. How about your opinion? @Nic.
> 

after a second thinking, the first user of this helper is the patch to
extend mock iommu driver. Is it suitable to introduce a common API together
with selftest code?

https://lore.kernel.org/linux-iommu/20230921075138.124099-14-yi.l.liu@intel.com/

-- 
Regards,
Yi Liu