From nobody Sun Nov 9 23:38:59 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1552423640474470.5681282585764; Tue, 12 Mar 2019 13:47:20 -0700 (PDT) Received: from localhost ([127.0.0.1]:33122 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h3oIx-0007Cd-D8 for importer@patchew.org; Tue, 12 Mar 2019 16:47:19 -0400 Received: from eggs.gnu.org ([209.51.188.92]:50793) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h3nxE-00053o-Gu for qemu-devel@nongnu.org; Tue, 12 Mar 2019 16:24:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h3nxC-0002kU-GU for qemu-devel@nongnu.org; Tue, 12 Mar 2019 16:24:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34478) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h3nxA-0002ez-92 for qemu-devel@nongnu.org; Tue, 12 Mar 2019 16:24:48 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ACD3AC053FCE; Tue, 12 Mar 2019 20:24:45 +0000 (UTC) Received: from probe.redhat.com (ovpn-125-62.rdu2.redhat.com [10.10.125.62]) by smtp.corp.redhat.com (Postfix) with ESMTP id A422C60BF7; Tue, 12 Mar 2019 20:24:38 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org Date: Tue, 12 Mar 2019 16:23:34 -0400 Message-Id: <20190312202337.5278-20-jsnow@redhat.com> In-Reply-To: <20190312202337.5278-1-jsnow@redhat.com> References: <20190312202337.5278-1-jsnow@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 12 Mar 2019 20:24:45 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 19/22] docs/interop/qcow2: Improve bitmap flag in_use specification X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, Vladimir Sementsov-Ogievskiy , jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Vladimir Sementsov-Ogievskiy We already use (we didn't notice it) IN_USE flag for marking bitmap metadata outdated, such as AUTO flag, which mirrors enabled/disabled bitmaps. Now we are going to support bitmap resize, so it's good to write IN_USE meaning with more details. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-id: 20190311185147.52309-2-vsementsov@virtuozzo.com Signed-off-by: John Snow --- docs/interop/qcow2.txt | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt index 8c3098d8d9..af5711e533 100644 --- a/docs/interop/qcow2.txt +++ b/docs/interop/qcow2.txt @@ -633,7 +633,10 @@ Structure of a bitmap directory entry: Bit 0: in_use The bitmap was not saved correctly and may be - inconsistent. + inconsistent. Although the bitmap metadata is sti= ll + well-formed from a qcow2 perspective, the metadata + (such as the auto flag or bitmap size) or data + contents may be outdated. =20 1: auto The bitmap must reflect all changes of the virtual @@ -761,8 +764,8 @@ corresponding range of the virtual disk (see above) was= written to while the bitmap was 'enabled'. An unset bit means that this range was not written t= o. =20 The software doesn't have to sync the bitmap in the image file with its -representation in RAM after each write. Flag 'in_use' should be set while = the -bitmap is not synced. +representation in RAM after each write or metadata change. Flag 'in_use' +should be set while the bitmap is not synced. =20 In the image file the 'enabled' state is reflected by the 'auto' flag. If = this flag is set, the software must consider the bitmap as 'enabled' and start --=20 2.17.2