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Date:   Mon, 21 Nov 2022 15:57:45 -0800
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Subject: Re: [PATCH v7 02/20] x86/virt/tdx: Detect TDX during kernel boot
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To:     "Huang, Kai" <kai.huang@intel.com>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc:     "Hansen, Dave" <dave.hansen@intel.com>,
        "Luck, Tony" <tony.luck@intel.com>,
        "bagasdotme@gmail.com" <bagasdotme@gmail.com>,
        "ak@linux.intel.com" <ak@linux.intel.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
        "kirill.shutemov@linux.intel.com" <kirill.shutemov@linux.intel.com>,
        "Christopherson,, Sean" <seanjc@google.com>,
        "Chatre, Reinette" <reinette.chatre@intel.com>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "Yamahata, Isaku" <isaku.yamahata@intel.com>,
        "peterz@infradead.org" <peterz@infradead.org>,
        "Shahar, Sagi" <sagis@google.com>,
        "imammedo@redhat.com" <imammedo@redhat.com>,
        "Gao, Chao" <chao.gao@intel.com>,
        "Brown, Len" <len.brown@intel.com>,
        "Huang, Ying" <ying.huang@intel.com>,
        "Williams, Dan J" <dan.j.williams@intel.com>
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From:   Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
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On 11/21/22 1:37 AM, Huang, Kai wrote:
>> Also why is this global variable? At least in this patch, there seems to
>> be no use case.
> Platform_tdx_enabled() uses tdx_keyid_num to determine whether TDX is enabled by
> BIOS.
> 
> Also, in the changlog I can add "both initializing the TDX module and creating
> TDX guest will need to use TDX private KeyID".
> 
> But I also have a comment saying something similar around ...
> 

I am asking about the tdx_keyid_start. It mainly used in detect_tdx(). Maybe you
declared it as global as a preparation for next patches. But it is not explained
in change log.

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer