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 EBA2DCCF9F8 for ; Wed, 12 Nov 2025 13:05:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vJAXQ-0005es-TI; Wed, 12 Nov 2025 08:05:28 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vJA7j-0003KG-O8 for qemu-devel@nongnu.org; Wed, 12 Nov 2025 07:38:57 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vJA7g-0007H9-St for qemu-devel@nongnu.org; Wed, 12 Nov 2025 07:38:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762951131; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+0xSZ+KrD847vgH+oP7wUsgnb8iECnZJjObtHo+JI6g=; b=FcH4ZawuBPX/rhfotMOflJzcaiEaZ4KTKhcHLal/IlKO9vFFu9t2CGdmup+Jn0TCuQPN1R 3w7mLkhPPYgUGbjx6of9xiP6Dt+dLI6QTgkCJrIzGChbm2eR9ykPA51ey2fZnVl+2UT1jB tRwcG8v/syXUn4xJEajEOt+XC5W1vW0= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-650-a0bkWb2YM7mZi7lUdw_plQ-1; Wed, 12 Nov 2025 07:38:47 -0500 X-MC-Unique: a0bkWb2YM7mZi7lUdw_plQ-1 X-Mimecast-MFC-AGG-ID: a0bkWb2YM7mZi7lUdw_plQ_1762951127 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BD40C180034A; Wed, 12 Nov 2025 12:38:46 +0000 (UTC) Received: from localhost (unknown [10.44.32.14]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 137451955F1A; Wed, 12 Nov 2025 12:38:45 +0000 (UTC) Date: Wed, 12 Nov 2025 12:38:44 +0000 From: "Richard W.M. Jones" To: =?iso-8859-1?Q?Cl=E9ment?= Chigot Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org Subject: Re: [PATCH 0/5] block/vvfat: introduce "size" option Message-ID: <20251112123844.GA14264@redhat.com> References: <20250903075721.77623-1-chigot@adacore.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250903075721.77623-1-chigot@adacore.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=rjones@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Sep 03, 2025 at 09:57:16AM +0200, Clément Chigot wrote: > The main goal of this series is to introduce a new option "size" within > the vvfat backend (patch 5). It allows more control over SD cards' size. > The value for "Number of Heads" and "Sectors per track" are based on SD > specifications Part 2. > > This series also includes minor patches: > - patch 1 introduces another option to remove the Master Boot Record > (this is mandatory for QNX) > - patch 2-4 are minor improvements easing the introducing of "size" > option > > This was tested on with a aarch64-linux kernel taken from > functional/aarch64/test-virt and on aarch64-qnx over raspi4b with a > workaround, not included here (the SD bus must be associated to the EMMC2 > port instead of through GPIOs). > > Clément Chigot (5): > vvfat: introduce no-mbr option > vvfat: move fat_type check prior to size setup > vvfat: add a define for SECTOR_SIZE > vvfat: move size parameters within driver structure > vvfat: add support for "size" options > > block/vvfat.c | 279 ++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 213 insertions(+), 66 deletions(-) (Thanks Markus for bringing this thread up) I just wanted to say that a long time ago I wrote an nbdkit plugin that was intended as a more sane replacement for vfat. Since then several more nbdkit plugins have been added. They support arbitrary sizes already. The first one is the most direct replacement for vvfat (although it doesn't support writes to the backing directory, because that feature is insane). https://libguestfs.org/nbdkit-floppy-plugin.1.html https://libguestfs.org/nbdkit-iso-plugin.1.html https://libguestfs.org/nbdkit-linuxdisk-plugin.1.html https://libguestfs.org/nbdkit-tmpdisk-plugin.1.html Very easy to use from qemu as documented here: https://libguestfs.org/nbdkit-client.1.html#ATTACHING-NBD-DEVICES-TO-A-VIRTUAL-MACHINE Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org