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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1A2E3C33CB2 for ; Tue, 14 Jan 2020 13:59:56 +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 D978B214AF for ; Tue, 14 Jan 2020 13:59:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="XBiJ5PtJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D978B214AF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=igalia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40258 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irMja-0001GL-Rl for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 08:59:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52509) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irMiI-00080g-GD for qemu-devel@nongnu.org; Tue, 14 Jan 2020 08:58:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irMiE-0001BV-6D for qemu-devel@nongnu.org; Tue, 14 Jan 2020 08:58:34 -0500 Received: from fanzine.igalia.com ([178.60.130.6]:52889) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1irMiB-0001B0-UF; Tue, 14 Jan 2020 08:58:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From; bh=a9fjg3MM6VegbyHPvApFP0RNFDauRG63U8EPnn1FFiE=; b=XBiJ5PtJH21NGBKQfvcs96WgTQcMDI1vgEn2m5taV3z4NqODP8+2ma+4JEj18IJxFfnbiAa0OFbYmfpPLzTFd7fuTQq4N9/Aheon2iNEqwxBH38CteZHFHgNUvJabNGev0REuJpwdbCVtNt4lQgfkxJBuwadJiF08uUd9q++WfOc0JHmgqL35tcZfYarVyuMMDAYloiLqoNvUCoUWpfvrT0hChTkcuoeVpiGKqdPwESFnhEzhJF9xefSmJG939V17uHmUXcg8UIvH3su0UMuzp+bclKZgj+Ii9vrSXcm3wVHcruszEUSvZvUjp8a6rveb0SIksGip9NyMXELuIQAvA==; Received: from maestria.local.igalia.com ([192.168.10.14] helo=mail.igalia.com) by fanzine.igalia.com with esmtps (Cipher TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim) id 1irMi9-00046K-DO; Tue, 14 Jan 2020 14:58:25 +0100 Received: from berto by mail.igalia.com with local (Exim) id 1irMi8-0000H9-V4; Tue, 14 Jan 2020 14:58:24 +0100 From: Alberto Garcia To: Max Reitz , qemu-devel@nongnu.org Subject: Re: [PATCH v2 1/4] qcow2: Require that the virtual size is a multiple of the sector size In-Reply-To: <9f7ab60c-c9d4-527b-55dd-40f487a36895@redhat.com> References: <6a1cfcbb533b487bac96e1d2282ebf210954d27a.1578596897.git.berto@igalia.com> <9f7ab60c-c9d4-527b-55dd-40f487a36895@redhat.com> User-Agent: Notmuch/0.18.2 (http://notmuchmail.org) Emacs/24.4.1 (i586-pc-linux-gnu) Date: Tue, 14 Jan 2020 14:58:24 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Received-From: 178.60.130.6 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: Kevin Wolf , Nir Soffer , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue 14 Jan 2020 02:47:53 PM CET, Max Reitz wrote: >> Yes, but does it make sense to try to support images with unaligned >> sizes if no one is going to create them ever and QEMU cannot even >> generate them? > > If nobody uses such images ever, isn=E2=80=99t the current code fine as-i= s? I'll rephrase: 1. It is possible to have a qcow2 image with a size of 1 GB + 13 bytes (the size field in the qcow2 header allows it). 2. qemu-img cannot currently produce such images. 3. QEMU can open them but it gets the size wrong. 4. Fixing this in QEMU involves non-trivial changes (at least at the moment). 5. I don't think there's any use case for such images so instead of fixing QEMU I propose that we simply refuse to open them. Berto