Re: [PATCH v4 02/17] iommu: Add nested domain support

[Yi Liu <yi.l.liu@intel.com>]

On 2023/10/11 01:21, Jason Gunthorpe wrote:
> On Thu, Sep 21, 2023 at 12:51:23AM -0700, Yi Liu wrote:
>> From: Lu Baolu <baolu.lu@linux.intel.com>
>>
>> Introduce a new domain type for a user I/O page table, which is nested on
>> top of another user space address represented by a UNMANAGED
>> domain. The
> 
> Lets start using the world PAGING whenever you want to type
> UNMANAGED. I'm trying to get rid of UNMANAGED.

sure.

>> @@ -241,6 +245,21 @@ struct iommu_user_data {
>>   	size_t len;
>>   };
>>   
>> +/**
>> + * struct iommu_user_data_array - iommu driver specific user space data array
>> + * @uptr: Pointer to the user buffer array for copy_from_user()
>> + * @entry_len: The fixed-width length of a entry in the array, in bytes
>> + * @entry_num: The number of total entries in the array
>> + *
>> + * A array having a @entry_num number of @entry_len sized entries, each entry is
>> + * user space data, i.e. an uAPI that is defined in include/uapi/linux/iommufd.h
>> + */
>> +struct iommu_user_data_array {
>> +	void __user *uptr;
>> +	size_t entry_len;
>> +	int entry_num;
>> +};
> 
> Ditto about iommu-driver.h for most of this stuff

ack.

>> +
>>   /**
>>    * 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
>> @@ -263,6 +282,34 @@ static inline int iommu_copy_user_data(void *dst_data,
>>   				     src_data->uptr, src_data->len);
>>   }
>>   
>> +/**
>> + * iommu_copy_user_data_from_array - Copy iommu driver specific user space data
>> + *                                   from an iommu_user_data_array input
>> + * @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_array for user space data array
>> + * @index: Index to offset the location in the array to copy user data from
>> + * @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_from_array(void *dst_data,
>> +				const struct iommu_user_data_array *src_array,
>> +				int index, size_t data_len, size_t min_len)
> 
> Index should be 'unsigned int'

yes.

-- 
Regards,
Yi Liu