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 09B9DC43331 for ; Wed, 1 Apr 2020 10:01:54 +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 D1DB620772 for ; Wed, 1 Apr 2020 10:01:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1DB620772 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]:57394 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJaC1-0000k1-1o for qemu-devel@archiver.kernel.org; Wed, 01 Apr 2020 06:01:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41662) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJaB9-0008Ro-1m for qemu-devel@nongnu.org; Wed, 01 Apr 2020 06:01:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jJaB6-0007xS-KP for qemu-devel@nongnu.org; Wed, 01 Apr 2020 06:00:58 -0400 Received: from indium.canonical.com ([91.189.90.7]:55630) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1jJaB6-0007t0-DG for qemu-devel@nongnu.org; Wed, 01 Apr 2020 06:00:56 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1jJaB4-0001qe-NA for ; Wed, 01 Apr 2020 10:00:54 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id AE1502E8105 for ; Wed, 1 Apr 2020 10:00:54 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Wed, 01 Apr 2020 09:55:22 -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: twitek X-Launchpad-Bug-Reporter: Tobias Witek (twitek) X-Launchpad-Bug-Modifier: Tobias Witek (twitek) Message-Id: <158573492237.25129.5161164490189934653.malonedeb@soybean.canonical.com> Subject: [Bug 1870098] [NEW] [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: e371a18d49bfd25c32ac02cdadd1148c8fc90737 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" Public bug reported: 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 equ= al to the number of blocks in the disk (that is, the disk size divided by t= he 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. ** Affects: qemu Importance: Undecided Status: New -- = 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] cynamic 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