Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: 8RWUe7W8jqX16NB4wgz9Y8Qz8fAFpgVjhOEKri6h/N/RAR4P3WcnXMMtYWQuEfM5W0LWhLND67
 juV8Q/L/150g==
IronPort-SDR: FLN5JysCA+Gp5Oc3E4ZlMPbIVXuZ078nnQ1dj4cmnyZTtO81lkHOAFUSkrV7NLxaP+StjhuAQN
 Sjjvf87FUNnQ==
Subject: Re: [RFC v2 14/32] x86/tdx: Handle port I/O
To:     "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Dan Williams <dan.j.williams@intel.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        Raj Ashok <ashok.raj@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <cover.1619458733.git.sathyanarayanan.kuppuswamy@linux.intel.com>
 <0e7e94d1ee4bae49dfd0dd441dc4f2ab6df76668.1619458733.git.sathyanarayanan.kuppuswamy@linux.intel.com>
 <CAPcyv4jPLGs6p0PNZQB6yKB3QDtEcGb234zcgCbJutXxZZEGnA@mail.gmail.com>
 <e8ac31bc-e307-f277-f928-24ebba4cbca7@linux.intel.com>
 <CAPcyv4iuRdXooQvCzEWd9babzPij4nXpM-z5fai9+SGaeFYswQ@mail.gmail.com>
 <648fe68f-c521-dbba-4495-9a4d0498a3be@linux.intel.com>
From:   Andi Kleen <ak@linux.intel.com>
Message-ID: <96ffe033-9f60-b56e-d159-c1d0e8ae532b@linux.intel.com>
Date:   Mon, 10 May 2021 19:19:18 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.10.1
MIME-Version: 1.0
In-Reply-To: <648fe68f-c521-dbba-4495-9a4d0498a3be@linux.intel.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Precedence: bulk


On 5/10/2021 5:56 PM, Kuppuswamy, Sathyanarayanan wrote:
>
>
> On 5/10/21 4:34 PM, Dan Williams wrote:
>>>> Surely there's an existing macro for this pattern? Would
>>>> PUSH_AND_CLEAR_REGS + POP_REGS be suitable? Besides code sharing it
>>>> would eliminate clearing of %r8.
>>>
>>> There used to be SAVE_ALL/SAVE_REGS, but they have been all removed in
>>> some past refactorings.
>> Not a huge deal, but at a minimum it seems a generic construct that
>> deserves to be declared centrally rather than tdx-guest-port-io local.
>
> I can define SAVE_ALL_REGS/RESTORE_ALL_REGS. Do you want to move it 
> outside
> TDX code? I don't know if there will be other users for it?

The old name was SAVE_ALL / SAVE_REGS.

Yes please put it outside tdx code into some include file.

-Andi