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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1F282C43331 for ; Fri, 6 Sep 2019 19:02:28 +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 E7C46207FC for ; Fri, 6 Sep 2019 19:02:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7C46207FC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59408 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i6JV5-0004rM-3F for qemu-devel@archiver.kernel.org; Fri, 06 Sep 2019 15:02:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39576) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i6JT4-00040C-3w for qemu-devel@nongnu.org; Fri, 06 Sep 2019 15:00:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i6JT2-0005zM-3l for qemu-devel@nongnu.org; Fri, 06 Sep 2019 15:00:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54218) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i6JSx-0005Yv-2j; Fri, 06 Sep 2019 15:00:15 -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 A8E9718CB8E3; Fri, 6 Sep 2019 19:00:12 +0000 (UTC) Received: from [10.3.116.234] (ovpn-116-234.phx2.redhat.com [10.3.116.234]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BB2DE60BF7; Fri, 6 Sep 2019 19:00:11 +0000 (UTC) To: Maxim Levitsky , qemu-devel@nongnu.org References: <20190906173201.7926-1-mlevitsk@redhat.com> <20190906173201.7926-2-mlevitsk@redhat.com> <4dacc6bde5bc87d48f5d3b255a7a44bbded782ef.camel@redhat.com> From: Eric Blake Openpgp: preference=signencrypt Autocrypt: addr=eblake@redhat.com; keydata= xsBNBEvHyWwBCACw7DwsQIh0kAbUXyqhfiKAKOTVu6OiMGffw2w90Ggrp4bdVKmCaEXlrVLU xphBM8mb+wsFkU+pq9YR621WXo9REYVIl0FxKeQo9dyQBZ/XvmUMka4NOmHtFg74nvkpJFCD TUNzmqfcjdKhfFV0d7P/ixKQeZr2WP1xMcjmAQY5YvQ2lUoHP43m8TtpB1LkjyYBCodd+LkV GmCx2Bop1LSblbvbrOm2bKpZdBPjncRNob73eTpIXEutvEaHH72LzpzksfcKM+M18cyRH+nP sAd98xIbVjm3Jm4k4d5oQyE2HwOur+trk2EcxTgdp17QapuWPwMfhaNq3runaX7x34zhABEB AAHNHkVyaWMgQmxha2UgPGVibGFrZUByZWRoYXQuY29tPsLAegQTAQgAJAIbAwULCQgHAwUV CgkICwUWAgMBAAIeAQIXgAUCS8fL9QIZAQAKCRCnoWtKJSdDahBHCACbl/5FGkUqJ89GAjeX RjpAeJtdKhujir0iS4CMSIng7fCiGZ0fNJCpL5RpViSo03Q7l37ss+No+dJI8KtAp6ID+PMz wTJe5Egtv/KGUKSDvOLYJ9WIIbftEObekP+GBpWP2+KbpADsc7EsNd70sYxExD3liwVJYqLc Rw7so1PEIFp+Ni9A1DrBR5NaJBnno2PHzHPTS9nmZVYm/4I32qkLXOcdX0XElO8VPDoVobG6 gELf4v/vIImdmxLh/w5WctUpBhWWIfQDvSOW2VZDOihm7pzhQodr3QP/GDLfpK6wI7exeu3P pfPtqwa06s1pae3ad13mZGzkBdNKs1HEm8x6zsBNBEvHyWwBCADGkMFzFjmmyqAEn5D+Mt4P zPdO8NatsDw8Qit3Rmzu+kUygxyYbz52ZO40WUu7EgQ5kDTOeRPnTOd7awWDQcl1gGBXgrkR pAlQ0l0ReO57Q0eglFydLMi5bkwYhfY+TwDPMh3aOP5qBXkm4qIYSsxb8A+i00P72AqFb9Q7 3weG/flxSPApLYQE5qWGSXjOkXJv42NGS6o6gd4RmD6Ap5e8ACo1lSMPfTpGzXlt4aRkBfvb NCfNsQikLZzFYDLbQgKBA33BDeV6vNJ9Cj0SgEGOkYyed4I6AbU0kIy1hHAm1r6+sAnEdIKj cHi3xWH/UPrZW5flM8Kqo14OTDkI9EtlABEBAAHCwF8EGAEIAAkFAkvHyWwCGwwACgkQp6Fr SiUnQ2q03wgAmRFGDeXzc58NX0NrDijUu0zx3Lns/qZ9VrkSWbNZBFjpWKaeL1fdVeE4TDGm I5mRRIsStjQzc2R9b+2VBUhlAqY1nAiBDv0Qnt+9cLiuEICeUwlyl42YdwpmY0ELcy5+u6wz mK/jxrYOpzXKDwLq5k4X+hmGuSNWWAN3gHiJqmJZPkhFPUIozZUCeEc76pS/IUN72NfprZmF Dp6/QDjDFtfS39bHSWXKVZUbqaMPqlj/z6Ugk027/3GUjHHr8WkeL1ezWepYDY7WSoXwfoAL 2UXYsMAr/uUncSKlfjvArhsej0S4zbqim2ZY6S8aRWw94J3bSvJR+Nwbs34GPTD4Pg== Organization: Red Hat, Inc. Message-ID: <19dabeca-b99d-822e-84ad-0cc2be90d6c9@redhat.com> Date: Fri, 6 Sep 2019 14:00:10 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <4dacc6bde5bc87d48f5d3b255a7a44bbded782ef.camel@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="lT13HVBIDexdyTyExDYHMDxJvE7A9mhqj" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.63]); Fri, 06 Sep 2019 19:00:12 +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: Re: [Qemu-devel] [PATCH 1/3] block/qcow2: refactoring of threaded encryption code 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 , Vladimir Sementsov-Ogievskiy , =?UTF-8?Q?Daniel_P_=2e_Berrang=c3=a9?= , qemu-block@nongnu.org, qemu-stable , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --lT13HVBIDexdyTyExDYHMDxJvE7A9mhqj Content-Type: multipart/mixed; boundary="4esRjMsOY7P9eys5fKBWtD3ycWP9xSmTG"; protected-headers="v1" From: Eric Blake To: Maxim Levitsky , qemu-devel@nongnu.org Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , =?UTF-8?Q?Daniel_P_=2e_Berrang=c3=a9?= , qemu-block@nongnu.org, qemu-stable , Max Reitz Message-ID: <19dabeca-b99d-822e-84ad-0cc2be90d6c9@redhat.com> Subject: Re: [Qemu-devel] [PATCH 1/3] block/qcow2: refactoring of threaded encryption code References: <20190906173201.7926-1-mlevitsk@redhat.com> <20190906173201.7926-2-mlevitsk@redhat.com> <4dacc6bde5bc87d48f5d3b255a7a44bbded782ef.camel@redhat.com> In-Reply-To: <4dacc6bde5bc87d48f5d3b255a7a44bbded782ef.camel@redhat.com> --4esRjMsOY7P9eys5fKBWtD3ycWP9xSmTG Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 9/6/19 1:55 PM, Maxim Levitsky wrote: >>> +/* >>> + * qcow2_co_encrypt() >>> + * >>> + * Encrypts a sector size aligned contiguous area >>> + * >>> + * @host_cluster_offset - on disk offset of the cluster in which >>> + * the buffer resides >>> + * >>> + * @guest_offset - guest (virtual) offset of the buffer >>> + * @buf - buffer with the data to encrypt >>> + * @len - length of the buffer >>> + * >>> + * Note that the area is not cluster aligned and might cross a clust= er >>> + * boundary >> >> Umm, how is it possible for a sector to cross a cluster boundary? All= >> clusters are sector-aligned, and encryption only works on aligned >> sectors. Oh, I see - if @len is a multiple larger than sector size, >> then we have multiple sectors, and then indeed we may cross clusters. >> But then the docs about being 'a sector size aligned contiguous area' = is >> not quite right. >=20 > Why? the written area is always both aligned on _sector_ boundary > and multiple of the sector size. At least that what I see from > the existing asserts. I'm thinking it should read something like: Encrypts one or more contiguous aligned sectors to make it obvious that because there can be multiple sectors, there may indeed be a cluster boundary mid-length. My complaint was that the original text made it sound like there was exactly one sector (at which point @len is redundant, unless sectors are variably-sized) --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --4esRjMsOY7P9eys5fKBWtD3ycWP9xSmTG-- --lT13HVBIDexdyTyExDYHMDxJvE7A9mhqj Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAl1yrLoACgkQp6FrSiUn Q2pI2Af/amu+KIx4omLNJ5EW6NvPg4WbqExmVJLkGmnWxNbzXAyYgCvawL0ZM7ah JrE5phdIoYkgdFpTYW3yWQTW2lZ6BPH7svY2yL7agM4FrqnIPDDJ04l0zDvByhvq O/sr8uO3cSr+iCpRrC+gxfHRefZuI+387Yv1mwv4ej52c6Sam49eg41wI7UFTHUL W8ICHHSOCX8dk1qH+H7UKco6oQ9bJpVIkoiQhfREUsNXgknZq5rPrGEMcruOXBPr 0ebdQUw7escIlN/syxKN17CfVGLHU+4bI1AnRbwbxJNh29QtBgmKt5g3Lw0JgKCA n8UDGGbB3NIQjwVap/lQ4UKW95yRWw== =OriL -----END PGP SIGNATURE----- --lT13HVBIDexdyTyExDYHMDxJvE7A9mhqj--