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 CC1A9C43331 for ; Thu, 2 Apr 2020 06:51:29 +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 A242520784 for ; Thu, 2 Apr 2020 06:51:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A242520784 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34126 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJthI-0003RS-QU for qemu-devel@archiver.kernel.org; Thu, 02 Apr 2020 02:51:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49947) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJtgW-0002gj-Ga for qemu-devel@nongnu.org; Thu, 02 Apr 2020 02:50:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jJtgU-0005Qf-HF for qemu-devel@nongnu.org; Thu, 02 Apr 2020 02:50:40 -0400 Received: from indium.canonical.com ([91.189.90.7]:54112) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1jJtgT-0005Mg-4y for qemu-devel@nongnu.org; Thu, 02 Apr 2020 02:50:37 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1jJtgR-00026R-ML for ; Thu, 02 Apr 2020 06:50:35 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 9C3512E8023 for ; Thu, 2 Apr 2020 06:50:35 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Thu, 02 Apr 2020 06:44:37 -0000 From: Tobias Witek <1870098@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: kwolf-redhat twitek X-Launchpad-Bug-Reporter: Tobias Witek (twitek) X-Launchpad-Bug-Modifier: Tobias Witek (twitek) References: <158573492237.25129.5161164490189934653.malonedeb@soybean.canonical.com> Message-Id: <158580987719.12256.6926914189191813309.malone@chaenomeles.canonical.com> Subject: [Bug 1870098] Re: [block/vpc] cynamic disk header: off-by-one error for "num_bat_entries" X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="a296f04231dee355be5db73cc878b9e21689a253"; Instance="production-secrets-lazr.conf" X-Launchpad-Hash: 0b0c68294a28a7f40b38d9ab460f4ebeb91732d0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 91.189.90.7 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1870098 <1870098@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Ah, sorry, I failed to mention this: Due to this bug, qemu currently cannot create VHDs that are suitable for upload to Azure (because Azure expects disks that are aligned exactly to 1MB). If it would not be too much trouble for you to submit the patch, I would appreciate that a lot. I've never submitted a patch to qemu and the contribution doc reads somewhat complex, so I'm a bit concerned about dragging a very small patch out longer than strictly necessary. Thanks a lot! ** Summary changed: - [block/vpc] cynamic disk header: off-by-one error for "num_bat_entries" + [block/vpc] dynamic disk header: off-by-one error for "num_bat_entries" -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1870098 Title: [block/vpc] dynamic disk header: off-by-one error for "num_bat_entries" Status in QEMU: New Bug description: In current qemu versions (observed in 5.0.0-rc1 as well as 2833ad487cfff7dc33703e4731b75facde1c561e), disk headers for dynamic VPCs are written with an incorrect "block allocation table entries" value. https://www.microsoft.com/en-us/download/details.aspx?id=3D23850 (the corresponding spec) states that: "Max Table Entries This field holds the maximum entries present in the BAT. This should be e= qual to the number of blocks in the disk (that is, the disk size divided by= the block size)." Inside the qemu code, the value is "disk size divided by the block size *plus one*". Calculating "num_bat_entries" as "total_sectors/(block_size / 512)" *should* fix the issue. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1870098/+subscriptions