From nobody Sun Feb 8 19:37:55 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; 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 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1500993842165452.54378523057596; Tue, 25 Jul 2017 07:44:02 -0700 (PDT) Received: from localhost ([::1]:32941 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da141-00039Y-3J for importer@patchew.org; Tue, 25 Jul 2017 10:43:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36335) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da121-0001n9-Et for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:41:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1da11x-0000qb-2B for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:41:53 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:33044 helo=mx01.kamp.de) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1da11w-0000ow-Pg for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:41:49 -0400 Received: (qmail 14939 invoked by uid 89); 25 Jul 2017 14:41:44 -0000 Received: from [195.62.97.28] by client-16-kamp (envelope-from , uid 89) with qmail-scanner-2010/03/19-MF (clamdscan: 0.99.2/23595. avast: 1.2.2/17010300. spamassassin: 3.4.1. 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Processed in 0.315996 secs); 25 Jul 2017 14:41:44 -0000 Received: from smtp.kamp.de (HELO submission.kamp.de) ([195.62.97.28]) by mx01.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted); 25 Jul 2017 14:41:41 -0000 Received: (qmail 9620 invoked from network); 25 Jul 2017 14:41:40 -0000 Received: from lieven-pc.kamp-intra.net (HELO lieven-pc) (relay@kamp.de@::ffff:172.21.12.60) by submission.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted) ESMTPA; 25 Jul 2017 14:41:40 -0000 Received: by lieven-pc (Postfix, from userid 1000) id 4C04D20E91; Tue, 25 Jul 2017 16:41:40 +0200 (CEST) X-GL_Whitelist: yes From: Peter Lieven To: qemu-block@nongnu.org Date: Tue, 25 Jul 2017 16:41:30 +0200 Message-Id: <1500993699-19299-2-git-send-email-pl@kamp.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1500993699-19299-1-git-send-email-pl@kamp.de> References: <1500993699-19299-1-git-send-email-pl@kamp.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a02:248:0:51::16 Subject: [Qemu-devel] [PATCH V5 01/10] specs/qcow2: add compress format extension 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: kwolf@redhat.com, Peter Lieven , qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org, lersek@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Signed-off-by: Peter Lieven --- docs/interop/qcow2.txt | 51 ++++++++++++++++++++++++++++++++++++++++++++++= +++- roms/ipxe | 2 +- 2 files changed, 51 insertions(+), 2 deletions(-) diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt index d7fdb1f..d0d2a8f 100644 --- a/docs/interop/qcow2.txt +++ b/docs/interop/qcow2.txt @@ -86,7 +86,12 @@ in the description of a field. be written to (unless for regaining consistency). =20 - Bits 2-63: Reserved (set to 0) + Bit 2: Compress format bit. If and only if this = bit + is set then the compress format extension + MUST be present and MUST be parsed and che= cked + for compatibility. + + Bits 3-63: Reserved (set to 0) =20 80 - 87: compatible_features Bitmask of compatible features. An implementation can @@ -137,6 +142,7 @@ be stored. Each extension has a structure like the foll= owing: 0x6803f857 - Feature name table 0x23852875 - Bitmaps extension 0x0537be77 - Full disk encryption header pointer + 0xC03183A3 - Compress format extension other - Unknown header extension, can be safe= ly ignored =20 @@ -311,6 +317,49 @@ The algorithms used for encryption vary depending on t= he method in the LUKS header, with the physical disk sector as the input tweak. =20 + +=3D=3D Compress format extension =3D=3D + +The compress format extension is an optional header extension. It provides +the ability to specify the compress algorithm and compress parameters +that are used for compressed clusters. This new header MUST be present if +the incompatible-feature bit "compress format bit" is set and MUST be abse= nt +otherwise. + +The fields of the compress format extension are: + + Byte 0 - 13: compress_format_name (padded with zeros, but not + necessarily null terminated if it has full length). + Valid compression format names currently are: + + deflate: Standard zlib deflate compression without + compression header + + 14: compress_level (uint8_t) + + 0 =3D default compress level (valid for all formats, de= fault) + + Additional valid compression levels for deflate compres= sion: + + All values between 1 and 9. 1 gives best speed, 9 gives= best + compression. The default compression level is defined b= y zlib + and currently defaults to 6. + + 15: compress_window_size (uint8_t) + + Window or dictionary size used by the compression forma= t. + Currently only used by the deflate compression algorith= m. + + Valid window sizes for deflate compression range from 8= to + 15 inclusively. + +Note: Omitting the incompatible "Compress format bit" results in the usage +of deflate compression with default compression level and a window size of= 12 +(which was default before QEMU 2.11). If exactly these parameters are choo= sen +it is free to the implementation to omit the "Compress format bit" and the +compress format extension when updating the QCOW2 header. + + =3D=3D Host cluster management =3D=3D =20 qcow2 manages the allocation of host clusters by maintaining a reference c= ount diff --git a/roms/ipxe b/roms/ipxe index 0600d3a..b991c67 160000 --- a/roms/ipxe +++ b/roms/ipxe @@ -1 +1 @@ -Subproject commit 0600d3ae94f93efd10fc6b3c7420a9557a3a1670 +Subproject commit b991c67c1d91574ef22336cc3a5944d1e63230c9 --=20 1.9.1