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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 E6E5AC76190 for ; Fri, 26 Jul 2019 00:19:15 +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 B4E4421849 for ; Fri, 26 Jul 2019 00:19:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4E4421849 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35836 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqnx4-0004Kc-Sz for qemu-devel@archiver.kernel.org; Thu, 25 Jul 2019 20:19:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42468) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqnwu-0003v7-Oe for qemu-devel@nongnu.org; Thu, 25 Jul 2019 20:19:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hqnwt-0000Jz-Q6 for qemu-devel@nongnu.org; Thu, 25 Jul 2019 20:19:04 -0400 Received: from mga18.intel.com ([134.134.136.126]:52567) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hqnwt-0000Hy-Hc for qemu-devel@nongnu.org; Thu, 25 Jul 2019 20:19:03 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jul 2019 17:18:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,308,1559545200"; d="scan'208";a="198122683" Received: from joy-optiplex-7040.sh.intel.com (HELO joy-OptiPlex-7040) ([10.239.13.9]) by fmsmga002.fm.intel.com with ESMTP; 25 Jul 2019 17:18:56 -0700 Date: Thu, 25 Jul 2019 20:12:52 -0400 From: Yan Zhao To: "Dr. David Alan Gilbert" Message-ID: <20190726001251.GA27883@joy-OptiPlex-7040> References: <1563261042-15974-1-git-send-email-yan.y.zhao@intel.com> <20190725103907.GD2656@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190725103907.GD2656@work-vm> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.126 Subject: Re: [Qemu-devel] [PATCH] migration: notify runstate immediately before vcpu stops 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: , Reply-To: Yan Zhao Cc: "Tian, Kevin" , "cohuck@redhat.com" , "quintela@redhat.com" , "crosthwaite.peter@gmail.com" , "qemu-devel@nongnu.org" , "alex.williamson@redhat.com" , "pbonzini@redhat.com" , "rth@twiddle.net" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jul 25, 2019 at 06:39:07PM +0800, Dr. David Alan Gilbert wrote: > * Yan Zhao (yan.y.zhao@intel.com) wrote: > > for some devices to do live migration, it is needed to do something > > immediately before vcpu stops. add a notification here. > > > > Signed-off-by: Yan Zhao > > --- > > cpus.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/cpus.c b/cpus.c > > index b09b702..d5d4abe 100644 > > --- a/cpus.c > > +++ b/cpus.c > > @@ -1068,6 +1068,7 @@ static int do_vm_stop(RunState state, bool send_stop) > > int ret = 0; > > > > if (runstate_is_running()) { > > + vm_state_notify(1, state); > > SO that's quite interesting in that you'll end up getting a > notificatiion like 'running=true, state=RUN_STATE_SHUTDOWN' > that might be unexpected by existing callers. > > Have you checked existing callers? Also does this cause another event > to be sent on the QMP - if so we need to chekc if this would confuse > libvirt. > > Dave hi Dave yes, this may cause problem for existing handlers as this is an unexpected condition. like for ide's ide_restart_cb. So, do you think it's a better that do the notification earlier, before vm_stop_force_state() in migration.c and call notifier_list_notify(&migration_state_notifiers, s) to notify migration state instead ? Thanks Yan > > > cpu_disable_ticks(); > > pause_all_vcpus(); > > runstate_set(state); > > -- > > 2.7.4 > > > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK