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Date:   Tue, 10 Oct 2023 13:58:44 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Yi Liu <yi.l.liu@intel.com>
Cc:     joro@8bytes.org, alex.williamson@redhat.com, kevin.tian@intel.com,
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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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References: <20230921075138.124099-1-yi.l.liu@intel.com>
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On Thu, Sep 21, 2023 at 12:51:22AM -0700, Yi Liu wrote:
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 660dc1931dc9..12e12e5563e6 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -14,6 +14,7 @@
>  #include <linux/err.h>
>  #include <linux/of.h>
>  #include <uapi/linux/iommu.h>
> +#include <uapi/linux/iommufd.h>

Oh we should definately avoid doing that!
  
Maybe this is a good moment to start a new header file exclusively for
iommu drivers and core subsystem to include?

 include/linux/iommu-driver.h

?

Put iommu_copy_user_data() and  struct iommu_user_data in there

Avoid this include in this file.

>  #define IOMMU_READ	(1 << 0)
>  #define IOMMU_WRITE	(1 << 1)
> @@ -227,6 +228,41 @@ struct iommu_iotlb_gather {
>  	bool			queued;
>  };
>  
> +/**
> + * struct iommu_user_data - iommu driver specific user space data info
> + * @uptr: Pointer to the user buffer for copy_from_user()
> + * @len: The length of the user buffer in bytes
> + *
> + * A user space data is an uAPI that is defined in include/uapi/linux/iommufd.h
> + * Both @uptr and @len should be just copied from an iommufd core uAPI structure
> + */
> +struct iommu_user_data {
> +	void __user *uptr;
> +	size_t len;
> +};

Put the "hwpt_type" in here and just call it type

Jason