From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D1A013DB92 for ; Fri, 17 May 2024 17:37:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715967465; cv=none; b=U32iEiHyFxfz8btYUmnhHJ4/Jxc3EpUsssYCt58ym2Vg9i75BtQD7ijDOqqyU3x2oGpE/Bul3numGZZ6P1VCDx0YsM5ESV7SRrjpIUd0ec80p+c0vPSvGoa7Qif47deRH+99ZOAa2pKub/plBGaOCk3xZ+jXmv708G+w/vlVA3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715967465; c=relaxed/simple; bh=4fwMhfzb7fiHGB6Z+7pTdjWRCgM/C43wT1KTzj+itQs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fzTMajW1CMo0hpG7zriPFOwkuKmGKwY2BLaQIr0HmZfAgNhP18+fowjTVP0I2kUaio90Vw5eX+pExTrYRFuiFxFFmFGz1A13A+6urMGAH+iujuM4/X1jijAXhwLkflMRglPl6HXx/MAh5/TE9NpZkfWdKBjpfS5ZQfhFPRFoQWo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=hhBCQv2Y; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hhBCQv2Y" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1715967463; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=NEWIlFygRFbrzz7CO5yPIyO8pAuoM+szqWUDzEi5+48=; b=hhBCQv2YLlRUpJ3MmD24jHI5dJ7PN5pdi3rdPcwrzcnCEYtcDl7tfheT8YMyJnOQmMChNB D4qkn+c3hYRtnJQyoLQPhf8DUdQ1ftfRK3qOv42KiGoz8i3mRNcvXVBYh+7SwU83aQeOUy b9rJn4ZEz4j6ZMEnVe7At6m3O+x5ho4= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-219-MkeImVA9PAaavCo91Evz9A-1; Fri, 17 May 2024 13:37:41 -0400 X-MC-Unique: MkeImVA9PAaavCo91Evz9A-1 Received: by mail-ej1-f71.google.com with SMTP id a640c23a62f3a-a5a8f3bc8e0so259079466b.1 for ; Fri, 17 May 2024 10:37:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715967460; x=1716572260; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=NEWIlFygRFbrzz7CO5yPIyO8pAuoM+szqWUDzEi5+48=; b=cvKsJDlUrZ6JhESDqBWLwtZG0aopp4cm6TFS4gy7xeDh8++pFfiBiPhKv2/wRPfnxo O+nZhhQRgl3PY4mshqVNlklLcqm/DIDgaiAhSFv5tWStxY9uczz0y2O4fpU4+szS+0xe YAhD+LyVEUcgFCo7GT5FuZxEOLSJvEg1HqJ1OzsrceSAZHiNil0upA7xh2HwOhNKN4NA lliW+FW8reVQtw+IVmwXEm+lai/CdP0eibgHdzoYv2sJnlfxxjw/Bj7D/q9hPO52ljfd 6n2KMrAoGlIhT1Ti+ZdUUBUfOPW/hO3HEmEqSOfJOOy8EaQS4vM9mRse5VKrCCat4CmM aaag== X-Forwarded-Encrypted: i=1; AJvYcCXdzT1PyIlyYLgM5SUM5pwpBaRImDV4IXWsaZlZVNIx8q65XFbdiN4KTOIgt0iMCsG8v9IGNr5LVchazFw43+A0SMKubyaiSz2fXtnW X-Gm-Message-State: AOJu0YwgWefjfAwj4A8+egXodU6qorl+uKct900VagxoQeH4cvrAtCHc nXoRTP8USA47qRxNEtsAoM6pD5uAVQOPeIY+34zdVjHKasfChSCSJIkN/HVNCxovQJu0lt1LBF/ MUDqdcflJAGenmGaNkIq7LYOBZb+q0NyfJlu5/jsg2XJDOQ9NlzMPD7bmx5oaaA== X-Received: by 2002:a17:906:37d6:b0:a55:9dec:355f with SMTP id a640c23a62f3a-a5a2d676774mr1371413666b.70.1715967460411; Fri, 17 May 2024 10:37:40 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFKWPixH6mYyA8TAAYupqydQAjnpAf/qhf9Y/XZQ9Jx8TWF9XhpEP0k3m95s88l/5fQaoXnkQ== X-Received: by 2002:a17:906:37d6:b0:a55:9dec:355f with SMTP id a640c23a62f3a-a5a2d676774mr1371412066b.70.1715967460070; Fri, 17 May 2024 10:37:40 -0700 (PDT) Received: from [192.168.10.81] ([151.95.155.52]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-a5cdd444323sm293562366b.183.2024.05.17.10.37.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 17 May 2024 10:37:39 -0700 (PDT) Message-ID: <611a387b-ba7e-46d7-b6bf-84dc6c037d33@redhat.com> Date: Fri, 17 May 2024 19:37:38 +0200 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 03/20] x86/tdx: Convert port I/O handling to use new TDVMCALL macros To: Dave Hansen , "Kirill A. Shutemov" , Sean Christopherson , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Josh Poimboeuf , Peter Zijlstra Cc: linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org References: <20240517141938.4177174-1-kirill.shutemov@linux.intel.com> <20240517141938.4177174-4-kirill.shutemov@linux.intel.com> From: Paolo Bonzini Content-Language: en-US Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/17/24 17:28, Dave Hansen wrote: > On 5/17/24 07:19, Kirill A. Shutemov wrote: >> static inline void tdx_io_out(int size, u16 port, u32 value) >> { >> - struct tdx_module_args args = { >> - .r10 = TDX_HYPERCALL_STANDARD, >> - .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION), >> - .r12 = size, >> - .r13 = 1, >> - .r14 = port, >> - .r15 = value, >> - }; >> - >> - __tdx_hypercall(&args); >> + TDVMCALL_0(hcall_func(EXIT_REASON_IO_INSTRUCTION), >> + size, TDX_PORT_WRITE, port, value); >> } > > I actually really like the self-documenting nature of the structures. I > don't think it's a win if this is where the lines-of-code savings comes > from. > It's just a tradeoff. For example someone could well have written #define TDVMCALL_0(reason, a1, a2, a3, a4) \ do { \ struct tdx_module_args args = { .r10 = TDX_HYPERCALL_STANDARD, .r11 = reason, .r12 = a1, .r13 = a2, .r14 = a3, .r15 = a4, __tdx_hypercall(&args); } while(0) even with the current __tdx_hypercall() implementation. I agree that TDVMCALL_x is somewhat less legible; on the other hand it highlights that these TDVMCALLs all have a common convention for passing parameters / retrieving results, and reduces the potential for silly typos. This is also why I asked about the different approaches for TDCALL vs. TDVMCALL. Given that there are only a handful of appearances for tdvmcall_trampoline, maybe the best of both worlds is just to inline the whole thing? This way the code in the macros matches the parameter passing convention of the GHCI. Paolo