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=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 65361C43461 for ; Fri, 11 Sep 2020 18:50:47 +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 BFF102087C for ; Fri, 11 Sep 2020 18:50:46 +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="atOZmKmb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BFF102087C 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]:55980 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kGo8D-0007Cl-O5 for qemu-devel@archiver.kernel.org; Fri, 11 Sep 2020 14:50:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34502) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGo7P-0006L0-PN for qemu-devel@nongnu.org; Fri, 11 Sep 2020 14:49:55 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:42955 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kGo7O-0003NK-5O for qemu-devel@nongnu.org; Fri, 11 Sep 2020 14:49:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599850193; 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: in-reply-to:in-reply-to:references:references; bh=dKNgVZ0Zf+0Bj4F5BYXWJ2ztH/ltnx/ECH9VZWGY7NE=; b=atOZmKmbG2l7h1N93+tGoLxQLR7SZXch9ND8KZMsMq0449GbXPVWLcxJ+7RkkldWjvg5ex LVTIgHCqHJ9ovBE/pdfvYe99ZTjf+NGxVogU2t3u+CZTGUDDL3yX8syH6XJ+6zj2TfJufi 1YJbx0m7xiJ40/xvLbkSmHoTi7XCA2s= 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-153-Rpxi7911O4-DOKOh159jTQ-1; Fri, 11 Sep 2020 14:49:49 -0400 X-MC-Unique: Rpxi7911O4-DOKOh159jTQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 66AC81007480; Fri, 11 Sep 2020 18:49:48 +0000 (UTC) Received: from work-vm (ovpn-113-52.ams2.redhat.com [10.36.113.52]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D76F610013BD; Fri, 11 Sep 2020 18:49:29 +0000 (UTC) Date: Fri, 11 Sep 2020 19:49:27 +0100 From: "Dr. David Alan Gilbert" To: Steve Sistare Subject: Re: [PATCH V1 15/32] vl: QEMU_START_FREEZE env var Message-ID: <20200911184927.GU3310@work-vm> References: <1596122076-341293-1-git-send-email-steven.sistare@oracle.com> <1596122076-341293-16-git-send-email-steven.sistare@oracle.com> MIME-Version: 1.0 In-Reply-To: <1596122076-341293-16-git-send-email-steven.sistare@oracle.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0.003 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.120; envelope-from=dgilbert@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/11 09:43:46 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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: "Daniel P. Berrange" , "Michael S. Tsirkin" , Alex =?iso-8859-1?Q?Benn=E9e?= , Juan Quintela , qemu-devel@nongnu.org, Markus Armbruster , Alex Williamson , Stefan Hajnoczi , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , Paolo Bonzini , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Steve Sistare (steven.sistare@oracle.com) wrote: > For qemu upgrade and restart, we will re-exec() qemu with the same argv. > However, qemu must start in a paused state and wait for the cprload command, > and the original argv might not contain the -S option. To avoid modifying > argv, provide the QEMU_START_FREEZE environment variable. If > QEMU_START_FREEZE is set, then set autostart=0, like the -S option. > > Signed-off-by: Steve Sistare What's wrong with modifying the argv? Note, also the trick -incoming defer uses; the whole point here is that we start qemu with -incoming defer and then we can issue commands to modify the QEMU configuration before we actually reload state. Note, even without CPR there might be reasons that you need to modify the argv; for example, imagine that since it was originally booted someone had hotplug added an extra CPU or RAM or a disk; the new QEMU must be started in a state that reflects the state in which the VM was at the point when it was saved, not the point at which it was started long ago. Dave > --- > softmmu/vl.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 951994f..7016e39 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -4501,6 +4501,11 @@ void qemu_init(int argc, char **argv, char **envp) > exit(0); > } > > + if (getenv("QEMU_START_FREEZE")) { > + unsetenv("QEMU_START_FREEZE"); > + autostart = 0; > + } > + > if (incoming) { > Error *local_err = NULL; > qemu_start_incoming_migration(incoming, &local_err); > -- > 1.8.3.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK