From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5DA56C433EF for ; Wed, 24 Nov 2021 13:42:38 +0000 (UTC) Received: from localhost ([::1]:57372 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mpsXl-0007pT-21 for qemu-devel@archiver.kernel.org; Wed, 24 Nov 2021 08:42:37 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40836) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mps2B-0003Xj-8B; Wed, 24 Nov 2021 08:09:59 -0500 Received: from [2607:f8b0:4864:20::929] (port=41975 helo=mail-ua1-x929.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mps27-0007yi-GT; Wed, 24 Nov 2021 08:09:56 -0500 Received: by mail-ua1-x929.google.com with SMTP id p37so4940454uae.8; Wed, 24 Nov 2021 05:09:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=zRVsjmQa6gV8sHyGVx4OooHBV+LFb06gDpK50XnMUjE=; b=XQTQKtFzhaDsKa9M68TjdsOjcmztIQ7tTJtrAASH3uEVVM6l1LUMLaYwA0QHGZpIkK uorqnuGRGeFtIWf63hFDbFngDhvejVjjg4tc44Y/dX821g8Bol1+M9a1KDy4RYzUGZB5 y81nPF18ghuGJBEjwrW9Sopr9wEWOHHw0ojF8XbVN0LLACAj7pkwbWfJgEcvhAh4QH8g unj3B4my2gXDcRMJhpr8+fwuVPKm07mJXnhVJpfzYGv3NTG9aFHNgNphTZs3u3LsERg+ A1zT1wGq1CCrOLp5hQHDyDdmTChrs2gZjTONoYcv8lA1VNvJcl/UWFFBBComgb7myB+S oJpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=zRVsjmQa6gV8sHyGVx4OooHBV+LFb06gDpK50XnMUjE=; b=TX2FjGUX+SLnm1BlCRaBVczuL8V7NMPweqYfTp8Li6bLj1xpHbTVT0ettuUCdqMBW1 7YqwAp7xLyMUHyeyRex5er3PoLF5LXbl8q98864loAEABenH2RuEZ6xGlo3CUEeRyL39 EYgAy8aX2Z4k/j7drDAK+WUZ+56K25Nrdbien6THb+wJ96FiNNOlfpUvrmfB6hlMzwqY ex2bYys4FeBwvqGj/2pVZk4qTL6YlY5LvsPzrbBdMGKtD9QLvGmDnzJZVCF69hD2DT4K JKhE5ggYdmAjrCpdMDwFLEvyFSAxK+QI/rMjuH2Mb++3NP3P+4loM3dorWjzcdGzRrFy /wjg== X-Gm-Message-State: AOAM532Df4rpZbkgdjQSI2nb/SyN2WqygmWa5i61YovRzv3kFNbIfe/Y 2q2PytHdMzTE5UrYK35Taio= X-Google-Smtp-Source: ABdhPJwhkoD+pVoqDP8LeJHqxJWWqKSG0IqAp/Z0HV1qLEfnKaqzdhN+BhI5yVzBdGvs+jWlDBamzg== X-Received: by 2002:a05:6102:3a6d:: with SMTP id bf13mr23097067vsb.3.1637759394189; Wed, 24 Nov 2021 05:09:54 -0800 (PST) Received: from [192.168.10.222] ([191.19.215.188]) by smtp.gmail.com with ESMTPSA id u14sm7785052vkk.12.2021.11.24.05.09.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 24 Nov 2021 05:09:53 -0800 (PST) Message-ID: <7f5efc59-f097-9752-c4a0-3b7724e6f215@gmail.com> Date: Wed, 24 Nov 2021 10:09:51 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH for-7.0 v2 1/2] ivshmem.c: change endianness to LITTLE_ENDIAN Content-Language: en-US To: Markus Armbruster , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= References: <20211124092948.335389-1-danielhb413@gmail.com> <20211124092948.335389-2-danielhb413@gmail.com> <7d312ca5-82d1-ba63-535d-8024f2033215@redhat.com> <87lf1dyaqa.fsf@dusky.pond.sub.org> From: Daniel Henrique Barboza In-Reply-To: <87lf1dyaqa.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2607:f8b0:4864:20::929 (failed) Received-SPF: pass client-ip=2607:f8b0:4864:20::929; envelope-from=danielhb413@gmail.com; helo=mail-ua1-x929.google.com X-Spam_score_int: -51 X-Spam_score: -5.2 X-Spam_bar: ----- X-Spam_report: (-5.2 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, NICE_REPLY_A=-4.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com, qemu-devel@nongnu.org, clg@kaod.org, qemu-ppc@nongnu.org, Claudio Fontana , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 11/24/21 09:55, Markus Armbruster wrote: > Philippe Mathieu-Daudé writes: > >> On 11/24/21 10:29, Daniel Henrique Barboza wrote: >>> The ivshmem device, as with most PCI devices, uses little endian byte >>> order. However, the endianness of its mmio_ops is marked as >>> DEVICE_NATIVE_ENDIAN. This presents not only the usual problems with big >>> endian hosts but also with PowerPC little endian hosts as well, since >>> the Power architecture in QEMU uses big endian hardware (XIVE controller, >>> PCI Host Bridges, etc) even if the host is in little endian byte order. >> >> Maybe mention commit f7a199b2b44 ("ivshmem: use little-endian >> int64_t for the protocol")? > > "The protocol" is the interface between ivshmem-doorbell device (client) > and ivshmem server. This commit is about the interface between > ivshmem-* device and the guest. The two interfaces are about as related > as SSH and DNS: software exists that uses both. > Yeah, I was about to reply asking what's the relevance of how client-server communicates and the problem I'm trying to fix. It really seems a problem with the commit I mentioned in the "Fixes" tag that introduced the memory API with native endian instead of little endian. Let's keep the commit msg as is. Thanks, Daniel > Mentioning f7a199b2b44 feels superfluous to me. > > [...] >