Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <4940a38f-282b-7ce6-4d4c-2db1072ed3ca@intel.com>
Date:   Thu, 24 Feb 2022 16:51:22 -0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Content-Language: en-US
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        luto@kernel.org, peterz@infradead.org,
        sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com,
        ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com,
        hpa@zytor.com, jgross@suse.com, jmattson@google.com,
        joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org,
        pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com,
        tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com,
        thomas.lendacky@amd.com, brijesh.singh@amd.com, x86@kernel.org,
        linux-kernel@vger.kernel.org
References: <20220224155630.52734-1-kirill.shutemov@linux.intel.com>
 <20220224155630.52734-6-kirill.shutemov@linux.intel.com>
 <d51dc9c2-61e5-c8dd-e358-e4ab3d5429ac@intel.com>
 <20220224235413.lrzczn7re4mfdkup@black.fi.intel.com>
From:   Dave Hansen <dave.hansen@intel.com>
Subject: Re: [PATCHv4 05/30] x86/tdx: Extend the confidential computing API to
 support TDX guests
In-Reply-To: <20220224235413.lrzczn7re4mfdkup@black.fi.intel.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2/24/22 15:54, Kirill A. Shutemov wrote:
> 
>> Second, why have the global 'td_info' instead of just declaring it on
>> the stack.  It is only used within a single function.  Having it on the
>> stack is *REALLY* nice because the code ends up looking like:
>>
>> 	struct foo foo;
>> 	get_info(&foo);
>> 	cc_set_bar(foo.bar);
>>
>> The dependencies and scope are just stupidly obvious if you do that.
> Okay, I will rework it with plain gpa_width on stack and get_info(&gpa_width);
> Attributes will be needed after core enabling, so I will drop it from
> here.

I don't mind the 'struct tdx_info' if there's going to be more stuff in
it soon-ish.  Having a single member is fine for now.  Just make it
clear that the seamcall returns a bunch of stuff and only a subset of it
is used right now.