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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 52A63FA372C for ; Fri, 8 Nov 2019 15:21:49 +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 1CB4D21882 for ; Fri, 8 Nov 2019 15:21:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eNCvkc1F" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CB4D21882 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]:56096 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iT655-00081m-UA for qemu-devel@archiver.kernel.org; Fri, 08 Nov 2019 10:21:47 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47328) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iT5rZ-0000mf-TN for qemu-devel@nongnu.org; Fri, 08 Nov 2019 10:07:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iT5rY-0000cx-Nv for qemu-devel@nongnu.org; Fri, 08 Nov 2019 10:07:49 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:53524 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iT5rY-0000bN-Kt for qemu-devel@nongnu.org; Fri, 08 Nov 2019 10:07:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573225668; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vUnIBPXaVK5rgwpSnWNHv9XKDwdAafL3/CAVfQW4a3Q=; b=eNCvkc1FqPBfLQKNNua+rPoIwL3gj5nndkKpnYPJix8h/Rjisd9Rpm1+7A9wgMkNU7nDam G9X0bD8eZsxWrEe1EtXSbiUmrIzsKsexa4i2BMGeFbrr4Y7jTJ+T11M6szmfHyM3rZUHlY AjQoScRCLQB3za9elZFRCTLoE0eAV0A= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-285-YgJbfNyhMD6NLO_ZnjdZMA-1; Fri, 08 Nov 2019 10:07:44 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C977D477; Fri, 8 Nov 2019 15:07:43 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 641AB600CA; Fri, 8 Nov 2019 15:07:35 +0000 (UTC) Message-ID: Subject: Re: [PATCH v2 00/11] RFC crypto/luks: encryption key managment using amend interface From: Maxim Levitsky To: Max Reitz , qemu-devel@nongnu.org Date: Fri, 08 Nov 2019 17:07:35 +0200 In-Reply-To: References: <20190912223028.18496-1-mlevitsk@redhat.com> Mime-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: YgJbfNyhMD6NLO_ZnjdZMA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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 , "Daniel P. =?ISO-8859-1?Q?Berrang=E9?=" , qemu-block@nongnu.org, Markus Armbruster , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 2019-10-04 at 21:10 +0200, Max Reitz wrote: > On 13.09.19 00:30, Maxim Levitsky wrote: > > This patch series is continuation of my work to add encryption > > key managment to luks/qcow2 with luks. > >=20 > > This is second version of this patch set. > > The changes are mostly addressing the review feedback, > > plus I tested (and fixed sadly) the somewhat ugly code > > that allows to still write share a raw luks device, > > while preveting the key managment from happening in this case, > > as it is unsafe. > > I added a new iotest dedicated to that as well. > >=20 > > Best regards, > > =09Maxim Levitsky >=20 > At least for an RFC looks good from my perspective. I didn=E2=80=99t loo= k at > the crypto things very closely (assuming Dan would do so), and I didn=E2= =80=99t > check the iotests in detail. (But it definitely doesn=E2=80=99t look lik= e they > lack in breadth. Maybe I=E2=80=99d like to see a test that you cannot ha= ve > other useful nodes attached to the LUKS or qcow2 node while the > amendment process is ongoing (because CONSISTENT_READ is unshared). But > that=E2=80=99s the only thing I can think of.) Could you elaborate on this?=20 Inside the same process several users can access that luks node at the same time while one of them changes encryption keys, since this doesn't affect I= O of the data. Two users in same process I was *I think* told that can't do the amend in t= he same time since qmp is protected with a lock. However since I use a block job (to be = consistent with blockdev-create) I wonder if several qmp amend commands couldn't race one with another. Thes= e jobs is running on the block device AIO context (I changed this recently after a review), b= ut stil I am not sure there can't be a race. And when there is access to the same image from multiple processes, I do ha= ve a test that checks that as long as more that one process has the image open, noone can = change the encryption keys (this is only relevant for raw luks format, since for qcow2 this is forbidd= en anyway). I probably missed something though. Best regards, =09Maxim Levitsky >=20 > Max >=20