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=-11.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 AA8A2C4727D for ; Mon, 21 Sep 2020 23:47:06 +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 F0FDC23A6B for ; Mon, 21 Sep 2020 23:47:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="fryisHvy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0FDC23A6B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51446 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kKVWT-00046E-5V for qemu-devel@archiver.kernel.org; Mon, 21 Sep 2020 19:47:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47806) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kKVVh-0003fb-5D for qemu-devel@nongnu.org; Mon, 21 Sep 2020 19:46:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:40732) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kKVVf-0003uX-Br for qemu-devel@nongnu.org; Mon, 21 Sep 2020 19:46:16 -0400 Received: from localhost (c-67-164-102-47.hsd1.ca.comcast.net [67.164.102.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0265A23A65; Mon, 21 Sep 2020 23:46:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600731971; bh=787xebecrPi0gb3hcV0ivWfnEknCH+707PnyNQKMYlc=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=fryisHvyDKVeLD4Jug1+DJF7xBpf31KPWYzT39KLRnblJvxqlvUTQgvv+PjCSlaHr 0C94jTu69T7W6VVQpqMOpznfvbhpEWWREuPElqzPxBMzchHxM+E+xS1za5Y8NI/B+Y pBmEVFSXrAz0uto0B6yrUh+w68ctPjWjYCSNSgHg= Date: Mon, 21 Sep 2020 16:46:10 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: "Dr. David Alan Gilbert" Subject: Re: [PATCH] migration: Truncate state file in xen-save-devices-state In-Reply-To: <20200921175639.GP3221@work-vm> Message-ID: References: <20200921094830.114028-1-dovmurik@linux.vnet.ibm.com> <20200921111723.GF3221@work-vm> <20200921175639.GP3221@work-vm> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Received-SPF: pass client-ip=198.145.29.99; envelope-from=sstabellini@kernel.org; helo=mail.kernel.org X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/21 19:46:11 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -85 X-Spam_score: -8.6 X-Spam_bar: -------- X-Spam_report: (-8.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.455, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: sstabellini@kernel.org, Paul Durrant , Juan Quintela , qemu-devel@nongnu.org, Dov Murik , anthony.perard@citrix.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Adding Paul On Mon, 21 Sep 2020, Dr. David Alan Gilbert wrote: > * Dov Murik (dovmurik@linux.vnet.ibm.com) wrote: > > > > > > On 21/09/2020 14:17, Dr. David Alan Gilbert wrote: > > > * Dov Murik (dovmurik@linux.vnet.ibm.com) wrote: > > > > When running the xen-save-devices-state QMP command, if the filename > > > > already exists it will be truncated before dumping the devices' state > > > > into it. > > > > > > > > Signed-off-by: Dov Murik > > > > --- > > > > > > OK, that looks fine to me, so: > > > > > > Reviewed-by: Dr. David Alan Gilbert > > > > > > > > > > > Note that I found the above issue while trying to debug > > > > xen-load-devices-state which simply fails (prints "Configuration section > > > > missing" to stderr) directly after xen-save-devices-state (in the same > > > > VM). I wonder if I should file a bug report as-is or investigate some > > > > more. Advice welcome. > > > > > > I don't try the xen-* commands normally; I've cc'ing in Stefano and > > > Anthony. > > > > Thanks Dave. Just to be clear, I'm running this without Xen at all; but > > these commands seem to work OK for dumping/restoring guest's devices > > state (without RAM) -- if I modify the code to circumvent the mentioned > > problem. > > Yeh, although you can't rely on them not doing something Xen in the > future. There are a few other similar ways of doing what you want; eg. > if your RAM is 'shared' then you can set the x-ignore-shared migration > capability. > > Dave > > > Dov > > > > > > > > Dave > > > > > > > > > > > -Dov > > > > > > > > --- > > > > migration/savevm.c | 3 ++- > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/migration/savevm.c b/migration/savevm.c > > > > index 304d98ff78..e1b26672cc 100644 > > > > --- a/migration/savevm.c > > > > +++ b/migration/savevm.c > > > > @@ -2803,7 +2803,8 @@ void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live, > > > > vm_stop(RUN_STATE_SAVE_VM); > > > > global_state_store_running(); > > > > - ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT, 0660, errp); > > > > + ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT | O_TRUNC, > > > > + 0660, errp); > > > > if (!ioc) { > > > > goto the_end; > > > > } > > > > -- > > > > 2.20.1 > > > > > > > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >