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Subject: Re: [PATCH v7 3/7] iommu/uapi: Introduce enum type for PASID data
 format
To:     Jacob Pan <jacob.jun.pan@linux.intel.com>,
        iommu@lists.linux-foundation.org,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        Alex Williamson <alex.williamson@redhat.com>
Cc:     Lu Baolu <baolu.lu@linux.intel.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Yi Liu <yi.l.liu@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        Raj Ashok <ashok.raj@intel.com>,
        Christoph Hellwig <hch@infradead.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Jonathan Corbet <corbet@lwn.net>
References: <1596068467-49322-1-git-send-email-jacob.jun.pan@linux.intel.com>
 <1596068467-49322-4-git-send-email-jacob.jun.pan@linux.intel.com>
From:   Auger Eric <eric.auger@redhat.com>
Message-ID: <98781b4e-fe8e-fa65-4b77-c5221d241821@redhat.com>
Date:   Thu, 13 Aug 2020 11:29:04 +0200
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Hi Jacob,

On 7/30/20 2:21 AM, Jacob Pan wrote:
> There can be multiple vendor-specific PASID data formats used in UAPI
> structures. This patch adds enum type with a last entry which makes
> range checking much easier.
> 
> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>  include/uapi/linux/iommu.h | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
> index d5e9014f690e..abf4455a3495 100644
> --- a/include/uapi/linux/iommu.h
> +++ b/include/uapi/linux/iommu.h
> @@ -294,11 +294,16 @@ struct iommu_gpasid_bind_data_vtd {
>  					 IOMMU_SVA_VTD_GPASID_PCD |  \
>  					 IOMMU_SVA_VTD_GPASID_PWT)
>  
> +enum iommu_pasid_data_format {
> +	IOMMU_PASID_FORMAT_INTEL_VTD = 1,
> +	IOMMU_PASID_FORMAT_LAST,
> +};
> +
>  /**
>   * struct iommu_gpasid_bind_data - Information about device and guest PASID binding
>   * @argsz:	User filled size of this data
>   * @version:	Version of this data structure
> - * @format:	PASID table entry format
> + * @format:	PASID table entry format of enum iommu_pasid_data_format type
>   * @flags:	Additional information on guest bind request
>   * @gpgd:	Guest page directory base of the guest mm to bind
>   * @hpasid:	Process address space ID used for the guest mm in host IOMMU
> @@ -317,7 +322,6 @@ struct iommu_gpasid_bind_data {
>  	__u32 argsz;
>  #define IOMMU_GPASID_BIND_VERSION_1	1
>  	__u32 version;
> -#define IOMMU_PASID_FORMAT_INTEL_VTD	1
>  	__u32 format;
>  	__u32 addr_width;
>  #define IOMMU_SVA_GPASID_VAL	(1 << 0) /* guest PASID valid */
> 
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric