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 E9A2FC4727F for ; Fri, 25 Sep 2020 09:05:23 +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 3533321D91 for ; Fri, 25 Sep 2020 09:05:22 +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="PV4cEALN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3533321D91 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]:57292 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kLjfO-0000xi-2R for qemu-devel@archiver.kernel.org; Fri, 25 Sep 2020 05:05:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55592) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kLje8-0000Bo-Aa for qemu-devel@nongnu.org; Fri, 25 Sep 2020 05:04:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24382) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kLje5-00070y-Ij for qemu-devel@nongnu.org; Fri, 25 Sep 2020 05:04:03 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601024640; 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=aXvHtfuVOlkqoJoypJxIGAeTTW1MOP7VxHduXp9ZOQg=; b=PV4cEALNg1lW/uUq9yJuZvTuxWEns06ixTb4a2jWQiGKoAi8zwrjzTF4vZN6c3AbX3MFey p/eyzziSxE1YeXKHlkXhhyIk45fXxBim74Krdx95nLUIG5rE+ubrh8U0wfwiszTGkRV9MY amTE8RYAbVRsvoy4y6iuZoQZVG4cY3s= 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-464-lYVK6Po7OTGPVwcBA3Q_8w-1; Fri, 25 Sep 2020 05:03:58 -0400 X-MC-Unique: lYVK6Po7OTGPVwcBA3Q_8w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 45E2B10082EA; Fri, 25 Sep 2020 09:03:57 +0000 (UTC) Received: from work-vm (ovpn-114-177.ams2.redhat.com [10.36.114.177]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 971BF60C17; Fri, 25 Sep 2020 09:03:43 +0000 (UTC) Date: Fri, 25 Sep 2020 10:03:40 +0100 From: "Dr. David Alan Gilbert" To: Steven Sistare , mtosatti@redhat.com Subject: Re: [PATCH V1 11/32] cpu: disable ticks when suspended Message-ID: <20200925090340.GC2873@work-vm> References: <1596122076-341293-1-git-send-email-steven.sistare@oracle.com> <1596122076-341293-12-git-send-email-steven.sistare@oracle.com> <20200911175318.GQ3310@work-vm> <9b3fa2f8-2457-6c67-dd6e-c861cbd6f309@oracle.com> MIME-Version: 1.0 In-Reply-To: <9b3fa2f8-2457-6c67-dd6e-c861cbd6f309@oracle.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=63.128.21.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/25 01:07:33 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -32 X-Spam_score: -3.3 X-Spam_bar: --- X-Spam_report: (-3.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.199, 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_H5=0.001, RCVD_IN_MSPIKE_WL=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" * Steven Sistare (steven.sistare@oracle.com) wrote: > On 9/11/2020 1:53 PM, Dr. David Alan Gilbert wrote: > > * Steve Sistare (steven.sistare@oracle.com) wrote: > >> After cprload, the guest console misbehaves. You must type 8 characters > >> before any are echoed to the terminal. Qemu was not sending interrupts > >> to the guest because the QEMU_CLOCK_VIRTUAL timers_state.cpu_clock_offset > >> was bad. The offset is usually updated at cprsave time by the path > >> > >> save_cpr_snapshot() > >> vm_stop() > >> do_vm_stop() > >> if (runstate_is_running()) > >> cpu_disable_ticks(); > >> timers_state.cpu_clock_offset = cpu_get_clock_locked(); > >> > >> However, if the guest is in RUN_STATE_SUSPENDED, then cpu_disable_ticks is > >> not called. Further, the earlier transition to suspended in > >> qemu_system_suspend did not disable ticks. To fix, call cpu_disable_ticks > >> from save_cpr_snapshot. > >> > >> Signed-off-by: Steve Sistare > > > > Are you saying this is really a more generic bug with migrating when > > suspended and we should fix this anyway? > > Yes. Or when suspended and calling save_vmstate(), or qmp_xen_save_devices_state(). > Each of those functions needs the same fix unless someone identifies a more > centralized way in the state transition logic to disable ticks. OK, in that case please split this out of the series and we can take a fix as normal; please cc in mtosatti@redhat.com . Dave > > - Steve > > >> --- > >> migration/savevm.c | 5 +++++ > >> 1 file changed, 5 insertions(+) > >> > >> diff --git a/migration/savevm.c b/migration/savevm.c > >> index f101039..00f493b 100644 > >> --- a/migration/savevm.c > >> +++ b/migration/savevm.c > >> @@ -2729,6 +2729,11 @@ void save_cpr_snapshot(const char *file, const char *mode, Error **errp) > >> return; > >> } > >> > >> + /* Update timers_state before saving. Suspend did not so do. */ > >> + if (runstate_check(RUN_STATE_SUSPENDED)) { > >> + cpu_disable_ticks(); > >> + } > >> + > >> vm_stop(RUN_STATE_SAVE_VM); > >> > >> ret = qemu_savevm_state(f, op, errp); > >> -- > >> 1.8.3.1 > >> > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK