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Message-ID: <3075adc7-e02e-fcd4-44ef-c4228293f460@linux.intel.com>
Date:   Fri, 5 Aug 2022 14:35:35 -0700
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Subject: Re: [PATCH v10 1/2] x86/tdx: Add TDX Guest attestation interface
 driver
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To:     Wander Lairson Costa <wander@redhat.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H . Peter Anvin" <hpa@zytor.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kai Huang <kai.huang@intel.com>,
        Isaku Yamahata <isaku.yamahata@gmail.com>,
        marcelo.cerri@canonical.com, tim.gardner@canonical.com,
        khalid.elmously@canonical.com, philip.cox@canonical.com,
        linux-kernel@vger.kernel.org
References: <20220804003323.1441376-1-sathyanarayanan.kuppuswamy@linux.intel.com>
 <Yu1z0KcU5C2AJO6S@fedora>
From:   Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
In-Reply-To: <Yu1z0KcU5C2AJO6S@fedora>
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On 8/5/22 12:47 PM, Wander Lairson Costa wrote:
> On Wed, Aug 03, 2022 at 05:33:22PM -0700, Kuppuswamy Sathyanarayanan wrote:
>> +/**
>> + * struct tdx_report_req: Get TDREPORT using REPORTDATA as input.
>> + *
>> + * @subtype        : Subtype of TDREPORT (fixed as 0 by TDX Module
>> + *                   specification, but added a parameter to handle
>> + *                   future extension).
>> + * @reportdata     : User-defined REPORTDATA to be included into
>> + *                   TDREPORT. Typically it can be some nonce
>> + *                   provided by attestation service, so the
>> + *                   generated TDREPORT can be uniquely verified.
>> + * @rpd_len        : Length of the REPORTDATA (fixed as 64 bytes by
>> + *                   the TDX Module specification, but parameter is
>> + *                   added to handle future extension).
>> + * @tdreport       : TDREPORT output from TDCALL[TDG.MR.REPORT].
>> + * @tdr_len        : Length of the TDREPORT (fixed as 1024 bytes by
>> + *                   the TDX Module specification, but a parameter
>> + *                   is added to accommodate future extension).
>> + *
>> + * Used in TDX_CMD_GET_REPORT IOCTL request.
>> + */
>> +struct tdx_report_req {
>> +	__u8  subtype;
>> +	__u64 reportdata;
>> +	__u32 rpd_len;
>> +	__u64 tdreport;
>> +	__u32 tdr_len;
>> +};
> 
> Any reason why reportdata and tdreport aren't "void *"?

It is the recommended way to pass the pointers.

https://docs.kernel.org/driver-api/ioctl.html

> 
>> +
> 

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer