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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17DD6C0219B for ; Sun, 9 Feb 2025 20:42:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3F6656B0082; Sun, 9 Feb 2025 15:42:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3A5426B0083; Sun, 9 Feb 2025 15:42:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 293E26B0085; Sun, 9 Feb 2025 15:42:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 0C69D6B0082 for ; Sun, 9 Feb 2025 15:42:08 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 786B3121BA3 for ; Sun, 9 Feb 2025 20:42:07 +0000 (UTC) X-FDA: 83101578294.14.95151C6 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf22.hostedemail.com (Postfix) with ESMTP id B2F8AC0002 for ; Sun, 9 Feb 2025 20:42:05 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Mvb6ZNQq; spf=pass (imf22.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739133725; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PegLxjr7RGLlGHR54YwuPBdBXg3Ixf5ePUyHS8FCXNs=; b=0P1eXWEHFM2SCW2jYR8wOpTK+w1fmwM2HwWil59bVmAPu0Op4YP/lpAz+kBbFe48kjYsvr y+WStOtdCb842E6VBvGa5QYmc743IO2rnYG96jqmOdb9YLlKlTT5M9y1iez2hRrAzE4zf5 Y+bt2UDwzbYx5eP2oUhFKZ5yAWK5HgI= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Mvb6ZNQq; spf=pass (imf22.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739133725; a=rsa-sha256; cv=none; b=ojpdlypFBPOTsRQKp/ddfk0bayY5X2i9iJnw4tNVDLgLuHH+0f0sozLwY4HkYsuEf05ap7 Psi+gldGTEh4jx3BwNmoQGrHGfDxSA0xvqlXRJCBLUOcgdIooQjsDZnUTV83T4xu7Shbuk IEW42s4gB89DAmOZwsfkNy/+GEEOnok= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 0323C5C4A66; Sun, 9 Feb 2025 20:41:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB0C8C4CEDD; Sun, 9 Feb 2025 20:41:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739133724; bh=I5K6zxbY/URQKv0ExjhoGFG70Vc1gvwB7vWXZFIu2Cc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Mvb6ZNQqXlj09hq+unmSZoCfmod0TI+N53mH8hNPSmhVyaECG7qL/VeLfhSozBwyK bKp+3joGTS/8s3clIpcXU+Kf3coxgVOphSyzF4hIIfi6JPcitd2fnaTr4OYmTK+2eo HlHqV/qAg7XSOsMq2x0B+/PJIDWofzpZ5yMR8hNDTGhHx/Y9oX1jWuLDZoWAREW4+R DJBNXzGWKtGcx9XY6KOHAp5SdQBSySW6jRv0MlYbzTruhoFWCjOEJhK0IaUSIjok8i Gx7waD6FniX2f5APSdEPIG+AUN5MSH7PclqCC2YAZNH9a44UXgOHUXHV2I40nrNzbv P8DS5GHanX+6A== Date: Sun, 9 Feb 2025 22:41:46 +0200 From: Mike Rapoport To: Krzysztof Kozlowski Cc: linux-kernel@vger.kernel.org, Alexander Graf , Andrew Morton , Andy Lutomirski , Anthony Yznaga , Arnd Bergmann , Ashish Kalra , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Dave Hansen , David Woodhouse , Eric Biederman , Ingo Molnar , James Gowans , Jonathan Corbet , Mark Rutland , Paolo Bonzini , Pasha Tatashin , "H. Peter Anvin" , Peter Zijlstra , Pratyush Yadav , Rob Herring , Rob Herring , Saravana Kannan , Stanislav Kinsburskii , Steven Rostedt , Thomas Gleixner , Tom Lendacky , Usama Arif , Will Deacon , devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [PATCH v4 14/14] Documentation: KHO: Add memblock bindings Message-ID: References: <20250206132754.2596694-1-rppt@kernel.org> <20250206132754.2596694-15-rppt@kernel.org> <45df0d7a-622a-4268-9683-c5c6067483c3@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Stat-Signature: ifqwaigonn8zoxjqfh9ehb5xoz8ihdaz X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B2F8AC0002 X-HE-Tag: 1739133725-174777 X-HE-Meta: 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 qj2H8M7H n15IJ9dM0ZJqvT1kbmYRTH+5E+4hpcFtMor9E0e/ECuDxhWTpyx1bxPYfWYdUlIhVqpiUUdeaPMnbthZEnd/CfR64XPHuorGidFXXmWKow6o3tPQxor+/h8IdTGYE3h+CWPI+R3VVFkEdIlQrmmdjx157AErjyS/aNNN0pBQ6RjDL6aPXaRTxW/x4RYj7g2vJpZZQFPXPgvkHTGiJ/HecB5/8KYV7t+fxTTLJ0G5fntrQjTCH1p2zu9il5dD/c9UWPFHUHDwW5URowdtspDf7rO2A+TEZ4rbcUF/tgxzt87Id7Z/dU0SB1ywV31ADZhx/QV3hD5vVnYuouzOrBnUt+La4DrDnWbxCgZ96qLbCbI/c621Lor2e146VZJnwiXg1X6he0XTf9JxC/2wZZQXEuokaFZ/YEmYylvWxrtZzeBtm+QM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Feb 09, 2025 at 04:23:09PM +0100, Krzysztof Kozlowski wrote: > On 09/02/2025 16:10, Mike Rapoport wrote: > > On Sun, Feb 09, 2025 at 11:29:41AM +0100, Krzysztof Kozlowski wrote: > >> On 06/02/2025 14:27, Mike Rapoport wrote: > >>> From: "Mike Rapoport (Microsoft)" > >>> > >>> We introduced KHO into Linux: A framework that allows Linux to pass > >>> metadata and memory across kexec from Linux to Linux. KHO reuses fdt > >>> as file format and shares a lot of the same properties of firmware-to- > >>> Linux boot formats: It needs a stable, documented ABI that allows for > >>> forward and backward compatibility as well as versioning. > >> > >> Please use subject prefixes matching the subsystem. You can get them for > >> example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory > >> your patch is touching. For bindings, the preferred subjects are > >> explained here: > >> https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters > > > > These are not devicetree binding for communicating data from firmware to > > the kernel. These bindings are specific to KHO which is perfectly > > reflected by the subject. > > No, it is not. None of the bindings use above subject prefix. > > > > > Just a brief reminder from v2 discussion: > > (https://lore.kernel.org/linux-mm/20231222193607.15474-1-graf@amazon.com/) > > > > "For quick reference: KHO is a new mechanism this patch set introduces > > which allows Linux to pass arbitrary memory and metadata between kernels > > on kexec. I'm reusing FDTs to implement the hand over protocol, as > > Linux-to-Linux boot communication holds very similar properties to > > firmware-to-Linux boot communication. So this binding is not about > > hardware; it's about preserving Linux subsystem state across kexec. > > does not matter. You added file to ABI documentation so you must follow > that ABI documentation rules. One rule is proper subject prefix. No, it does not. It's a different ABI. FDT is a _data structure_ that provides cross platform unified, versioned, introspectable data format. Documentation/devicetree/bindings standardizes it's use for describing hardware, but KHO uses FDT _data structure_ to describe state of the kernel components that will be reused by the kexec'ed kernel. KHO is a different namespace from Open Firmware Device Tree, with different requirements and different stakeholders. Putting descriptions of KHO data formats in Documentation/kho rather than in Documentation/devicetree/bindings was not done to evade review of Open Firmware Device Tree maintainers, but rather to emphasize that KHO FDT _is not_ Open Firmware Device Tree. > Best regards, > Krzysztof -- Sincerely yours, Mike.