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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B8283C76196 for ; Thu, 6 Apr 2023 20:25:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pkWAT-0001Ng-3W; Thu, 06 Apr 2023 16:25:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pkWAQ-0001N8-Mf; Thu, 06 Apr 2023 16:25:10 -0400 Received: from 77-173-18-117.fixed.kpn.net ([77.173.18.117] helo=gorilla.13thmonkey.org) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pkWAO-0001jv-Ma; Thu, 06 Apr 2023 16:25:10 -0400 Received: by gorilla.13thmonkey.org (Postfix, from userid 103) id 579ED2FF0958; Thu, 6 Apr 2023 22:23:59 +0200 (CEST) Date: Thu, 6 Apr 2023 22:23:59 +0200 From: Reinoud Zandijk To: Kevin Wolf Cc: Michael Tokarev , Alex =?iso-8859-1?Q?Benn=E9e?= , qemu-devel@nongnu.org, Paolo Bonzini , Reinoud Zandijk , Ryo ONODERA , qemu-block@nongnu.org, Hanna Reitz , Warner Losh , Beraldo Leal , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Kyle Evans , kvm@vger.kernel.org, Wainer dos Santos Moschetta , Cleber Rosa , Thomas Huth , armbru@redhat.com Subject: Re: [PATCH v2 05/11] qemu-options: finesse the recommendations around -blockdev Message-ID: References: <20230403134920.2132362-1-alex.bennee@linaro.org> <20230403134920.2132362-6-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Received-SPF: none client-ip=77.173.18.117; envelope-from=reinoud@gorilla.13thmonkey.org; helo=gorilla.13thmonkey.org X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, KHOP_HELO_FCRDNS=0.015, SPF_HELO_NONE=0.001, SPF_NONE=0.001, TVD_RCVD_IP=0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Apr 04, 2023 at 06:17:45PM +0200, Kevin Wolf wrote: > Am 04.04.2023 um 17:07 hat Michael Tokarev geschrieben: > > 04.04.2023 16:57, Kevin Wolf пишет: > Maybe -snapshot should error out if -blockdev is in use. You'd generally > expect that either -blockdev is used primarily and snapshots are done > externally (if the command line is generated by some management tool), > or that -drive is used consistently (by a human who likes the > convenience). In both cases, we wouldn't hit the error path. > > There may be some exceptional cases where you have both -drive and > -blockdev (maybe because a human users needs more control for one > specific disk). This is the case where you can get a nasty surprise and > that would error out. If you legitimately want the -drive images > snapshotted, but not the -blockdev ones, you can still use individual > '-drive snapshot=on' options instead of the global '-snapshot' (and the > error message should mention this). I didn't know that! I normally use the -snapshot as global option. Is there a reason why -blockdev isn't honouring -snapshot? With regards, Reinoud