From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0D4B4635; Wed, 30 Jul 2025 09:49:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753868961; cv=none; b=T4vUDx4ahBTZ3v60gn4y9qHvZorGrnV5fwYRTtLgsl0rDR2VGA/D7k5OkOyma1YP0T0Z+BObR3mPO/y1awSFiMzHCUitMYYAZO//ndnP1mq0qAiKMucQHwMrgARUcUcXo8cWaKQvMba3YjVAZpSXCz7mB9mwePuZLfsllBVqDKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753868961; c=relaxed/simple; bh=UimlKP3HSONXYCOXhI5k/xeHFAvvYzDBkpGyXWw4lgU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OMkDTtEQHEk7vV3WsJOrFAvONhflKKb7eGSl9yVlOUrTFbyNeFpDeGASKcw/1KcWs8dwtwEvGfPkiODmOhKoHIfZOrjsBGJQPUjd+HVpTzQME5meC+T4dUAsgMvs30ZLRFKowjuTtr9uaxRyaYiZbn+5taQbjWq1tW/Wqo7F0tc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=u0l0FvA7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="u0l0FvA7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B123C4CEF6; Wed, 30 Jul 2025 09:49:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753868960; bh=UimlKP3HSONXYCOXhI5k/xeHFAvvYzDBkpGyXWw4lgU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=u0l0FvA7Sm1rh+7Sx/2QZ6/Uq1zhgLUSU8BykuTP2Enw+rHBCAztUZT7XxPeg2hAQ Jel8Ha8NMkVppS9NELGZCEPO7XjSalYDa+M8WweEzICFlobk4/Kvq7hpfSQgGmijX0 bY0euDSjUbTIMZhUm9L9yzSQ2ULOpU+X9JykUfQcSOHhR/LmProiQw0ctpCDnHY+fR EyUAk9mePNWDvtt+F9AIU6Z40etr890Y9IQSSQeuSxHw++lMJNB5PbzGkXCVBFtoQq 6LmdjEcqM2EjQzVftBwdWkDkDPmFLJH37P5KEcHr9KXzbOwZqrA5F0JQCTZ0ZP2U3O Zpj7N3ohZsJIA== Message-ID: <1ba0e803-cbca-43d0-be9d-79fef4e54201@kernel.org> Date: Wed, 30 Jul 2025 11:49:14 +0200 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 6/6] virtio-msg: Add support for loopback bus To: Viresh Kumar , linux-kernel@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= Cc: Arnd Bergmann , Vincent Guittot , =?UTF-8?Q?Alex_Benn=C3=A9e?= , Bill Mills , Rob Herring , Saravana Kannan , devicetree@vger.kernel.org, virtualization@lists.linux.dev, Sudeep Holla , Bertrand Marquis , "Edgar E . Iglesias" , Arnaud Pouliquen , Krzysztof Kozlowski , Conor Dooley References: <622460b11118be66d5ec380b3d5771be77fc1e91.1753865268.git.viresh.kumar@linaro.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: <622460b11118be66d5ec380b3d5771be77fc1e91.1753865268.git.viresh.kumar@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 30/07/2025 11:29, Viresh Kumar wrote: > Add a loopback bus implementation for the virtio-msg transport. > > This bus simulates a backend that echoes messages to itself, allowing > testing and development of virtio-msg without requiring an actual remote > backend or transport hardware. > > The loopback bus requires a reserved memory region for its operation. > All DMA-coherent and streaming DMA allocations are restricted to this > region, enabling safe mapping into user space and helping validate the > memory-sharing model. > > The reserved-memory region must be named "vmsglb" in the device tree. No, because I can name regions how I wish. You cannot add undocumented ABI and claim in commit msg, that the commit msg is the ABI. Either you have ABI documented or you cannot rely on implicit ABI, thus remove above restriction. This is really poor choice to add such hidden ABI and it already broke several users in the past. Best regards, Krzysztof