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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74ED3C77B6F for ; Thu, 6 Apr 2023 20:33:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239885AbjDFUdP (ORCPT ); Thu, 6 Apr 2023 16:33:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239605AbjDFUcm (ORCPT ); Thu, 6 Apr 2023 16:32:42 -0400 X-Greylist: delayed 474 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 06 Apr 2023 13:31:59 PDT Received: from gorilla.13thmonkey.org (77-173-18-117.fixed.kpn.net [77.173.18.117]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6558E7683 for ; Thu, 6 Apr 2023 13:31:59 -0700 (PDT) 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: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.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