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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BC6DC433DB for ; Thu, 28 Jan 2021 10:31:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9CD964DD8 for ; Thu, 28 Jan 2021 10:31:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232424AbhA1Kb1 convert rfc822-to-8bit (ORCPT ); Thu, 28 Jan 2021 05:31:27 -0500 Received: from relay11.mail.gandi.net ([217.70.178.231]:38335 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231615AbhA1KbR (ORCPT ); Thu, 28 Jan 2021 05:31:17 -0500 Received: from xps13 (lfbn-tou-1-972-150.w86-210.abo.wanadoo.fr [86.210.203.150]) (Authenticated sender: miquel.raynal@bootlin.com) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 9520110000F; Thu, 28 Jan 2021 10:30:27 +0000 (UTC) Date: Thu, 28 Jan 2021 11:30:26 +0100 From: Miquel Raynal To: Richard Weinberger Cc: miklos@szeredi.hu, vigneshr@ti.com, boris.brezillon@collabora.com, rminnich@google.com, sven@narfation.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, fuse-devel@lists.sourceforge.net Subject: Re: [PATCH 0/8] MUSE: Userspace backed MTD v3 Message-ID: <20210128113026.094b07b0@xps13> In-Reply-To: <20210124232007.21639-1-richard@nod.at> References: <20210124232007.21639-1-richard@nod.at> Organization: Bootlin X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Richard, Richard Weinberger wrote on Mon, 25 Jan 2021 00:19:59 +0100: > I'm happy to announce the first non-RFC version of this patch set. > Over the xmas holidays I found some time to experiment with various userspace > implementations of MTDs and gave the kernel side more fine-tuning. > > Rationale: > ---------- > > When working with flash devices a common task is emulating them to run various > tests or inspect dumps from real hardware. To achieve that we have plenty of > emulators in the MTD subsystem: mtdram, block2mtd, nandsim. > > Each of them implements an ad-hoc MTD and have various drawbacks. > Over the last years some developers tried to extend them but these attempts > often got rejected because they added just more adhoc feature instead of > addressing overall problems. > > MUSE is a novel approach to address the need of advanced MTD emulators. > Advanced means in this context supporting different (vendor specific) image > formats, different ways for fault injection (fuzzing) and recoding/replaying > IOs to emulate power cuts. > > The core goal of MUSE is having the complexity on the userspace side and > only a small MTD driver in kernelspace. > While playing with different approaches I realized that FUSE offers everything > we need. So MUSE is a little like CUSE except that it does not implement a > bare character device but an MTD. I can't tell if your MUSE implementation is right but it looks fine on the MTD side. This is following the right path, I look forward to merging it soon! Thanks for your contribution, Miquèl