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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 33460C35656 for ; Fri, 21 Feb 2020 16:41:59 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0BE5F24650 for ; Fri, 21 Feb 2020 16:41:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BE5F24650 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33022 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j5BNG-00065q-8m for qemu-devel@archiver.kernel.org; Fri, 21 Feb 2020 11:41:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51518) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j5BKu-0003mK-QR for qemu-devel@nongnu.org; Fri, 21 Feb 2020 11:39:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j5BKt-0003zb-NL for qemu-devel@nongnu.org; Fri, 21 Feb 2020 11:39:32 -0500 Received: from mail-ot1-f67.google.com ([209.85.210.67]:45873) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1j5BKt-0003yx-IY for qemu-devel@nongnu.org; Fri, 21 Feb 2020 11:39:31 -0500 Received: by mail-ot1-f67.google.com with SMTP id 59so2502556otp.12 for ; Fri, 21 Feb 2020 08:39:31 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4BgZBtTDREnYAapVdHrqgQ9W3R4CTcWbIkMjaCPQlXs=; b=KXUVpLbi3u3qAL/PfQGiydOxkmaeXY+F9DSerLxflqhSj09QHARVAssIHY0+9Jmsid 1tM13M/mgK1t2SB2yoyjVvErcCjhkroBJGxp+Yvoy83b4A/dmIAEWW7Sx37osHN4T6e2 7vFXYjBJEZle2TG/njMEu9V2tg8HPIuaUAWCXbsoB/2I+teQ5tPqKIR3PQWWObh7T26c 7DfGfXoklfxt9ttEj1ZmJk7VvF25OSBELwtPPeFJG8IAsOmqoxIgO3Rwcyy3/cbCSIZU wWPYnt22r6s3oqC79IJos5rB/7lrWmOHjf9x5vCxJxYvPoHjiX590RpeK1typBh5seuD +qPg== X-Gm-Message-State: APjAAAUPVyrepWU7JHB+2bL6/jqsPf3FQ1LqPyiUs1D1v3ABbF59fJ3W e6YgPmR+L60rJezAM6YwwGmDCNYTp4YjsVkIvuQ= X-Google-Smtp-Source: APXvYqyHdwKbUhPCfLeqiqCgnHSzlLvGxUb88yDmpTUxNb9KdZfgkLsmdvKxBtKDh+BkPpxepYgxvBCP9OOjR7Ep3ks= X-Received: by 2002:a9d:dc1:: with SMTP id 59mr29016938ots.250.1582303170916; Fri, 21 Feb 2020 08:39:30 -0800 (PST) MIME-Version: 1.0 References: <20200218151812.7816-1-geert+renesas@glider.be> In-Reply-To: <20200218151812.7816-1-geert+renesas@glider.be> From: Geert Uytterhoeven Date: Fri, 21 Feb 2020 17:39:19 +0100 Message-ID: Subject: Re: [PATCH v5 0/5] gpio: Add GPIO Aggregator To: Linus Walleij , Bartosz Golaszewski Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.85.210.67 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , QEMU Developers , Phil Reid , Geert Uytterhoeven , Jonathan Corbet , Marc Zyngier , "open list:DOCUMENTATION" , Magnus Damm , Christoffer Dall , Linux Kernel Mailing List , Linux-Renesas , "open list:GPIO SUBSYSTEM" , Rob Herring , Alexander Graf , Paolo Bonzini , Harish Jenny K N , Eugeniu Rosca Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Linus and Bartosz, On Tue, Feb 18, 2020 at 4:18 PM Geert Uytterhoeven wrote: > GPIO controllers are exported to userspace using /dev/gpiochip* > character devices. Access control to these devices is provided by > standard UNIX file system permissions, on an all-or-nothing basis: > either a GPIO controller is accessible for a user, or it is not. > Currently no mechanism exists to control access to individual GPIOs. > > Hence this adds a GPIO driver to aggregate existing GPIOs, and expose > them as a new gpiochip. This is useful for implementing access control, > and assigning a set of GPIOs to a specific user. Furthermore, this > simplifies and hardens exporting GPIOs to a virtual machine, as the VM > can just grab the full GPIO controller, and no longer needs to care > about which GPIOs to grab and which not, reducing the attack surface. Do you have any more comments, before I respin and post v6? Thanks, and have a niec weekend! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds