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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 81676C33CB1 for ; Tue, 14 Jan 2020 13:07:20 +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 4971A24676 for ; Tue, 14 Jan 2020 13:07:20 +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="Xkk1bZQ0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4971A24676 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]:39064 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irLuh-0000k2-5G for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 08:07:19 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40785) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irLi4-0001i2-IY for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:54:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irLi3-0001Z0-Dq for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:54:16 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:54356 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1irLi3-0001Yl-9t for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:54:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579006454; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ep/mdFe58oIx18pwRhWkg/D1I02FCTVyA7jE4yQkeXs=; b=Xkk1bZQ0RW4pzigj6SiVnkNrk9qOppsLU3Nd2B5cQYOSzpeqy7Z/GgrD36QmGhzo/liUfV zaOxRnxafwzcCzgpYHhQnGld0pVYwaN2DPjNKZcfhIP7oCRwyY9E2fpoPKvX6taHjsBkFM 29+OAHYzaSlnSgj9ncOQMUdQyZMBw8w= 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-173-zv9B_jHhPuOdtm39MNB3WA-1; Tue, 14 Jan 2020 07:54:13 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A07F2802B6E; Tue, 14 Jan 2020 12:54:11 +0000 (UTC) Received: from secure.mitica (ovpn-116-207.ams2.redhat.com [10.36.116.207]) by smtp.corp.redhat.com (Postfix) with ESMTP id EB51B5D9E5; Tue, 14 Jan 2020 12:54:04 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Subject: [PULL 07/30] runstate: ignore finishmigrate -> prelaunch transition Date: Tue, 14 Jan 2020 13:52:31 +0100 Message-Id: <20200114125254.4515-8-quintela@redhat.com> In-Reply-To: <20200114125254.4515-1-quintela@redhat.com> References: <20200114125254.4515-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: zv9B_jHhPuOdtm39MNB3WA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: Laurent Vivier , Peter Maydell , Thomas Huth , Corey Minyard , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Eduardo Habkost , Juan Quintela , Stefan Weil , Jason Wang , "Michael S. Tsirkin" , "Dr. David Alan Gilbert" , Stefan Berger , qemu-arm@nongnu.org, qemu-ppc@nongnu.org, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini , Richard Henderson , David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Laurent Vivier Commit 1bd71dce4bf2 tries to prevent a finishmigrate -> prelaunch transition by exiting at the beginning of the main_loop_should_exit() function if the state is already finishmigrate. As the finishmigrate state is set in the migration thread it can happen concurrently to the function. The migration thread and the function are normally protected by the iothread mutex and thus the state should no evolve between the start of the function and its end. Unfortunately during the function life the lock is released by pause_all_vcpus() just before the point we need to be sure we are not in finishmigrate state and if the migration thread is waiting for the lock it will take the opportunity to change the state to finishmigrate. The only way to be sure we are not in the finishmigrate state when we need is to check the state after the pause_all_vcpus() function. Fixes: 1bd71dce4bf2 ("runstate: ignore exit request in finish migrate state= ") Signed-off-by: Laurent Vivier Signed-off-by: Juan Quintela --- vl.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/vl.c b/vl.c index 158a05ed32..ba3e176094 100644 --- a/vl.c +++ b/vl.c @@ -1604,9 +1604,6 @@ static bool main_loop_should_exit(void) RunState r; ShutdownCause request; =20 - if (runstate_check(RUN_STATE_FINISH_MIGRATE)) { - return false; - } if (preconfig_exit_requested) { if (runstate_check(RUN_STATE_PRECONFIG)) { runstate_set(RUN_STATE_PRELAUNCH); @@ -1635,8 +1632,13 @@ static bool main_loop_should_exit(void) pause_all_vcpus(); qemu_system_reset(request); resume_all_vcpus(); + /* + * runstate can change in pause_all_vcpus() + * as iothread mutex is unlocked + */ if (!runstate_check(RUN_STATE_RUNNING) && - !runstate_check(RUN_STATE_INMIGRATE)) { + !runstate_check(RUN_STATE_INMIGRATE) && + !runstate_check(RUN_STATE_FINISH_MIGRATE)) { runstate_set(RUN_STATE_PRELAUNCH); } } --=20 2.24.1