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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_HK_NAME_DR,USER_AGENT_MUTT 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 A172CC28CC0 for ; Thu, 30 May 2019 19:18:43 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3941E260A4 for ; Thu, 30 May 2019 19:18:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3941E260A4 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 ([127.0.0.1]:58141 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hWQZW-0005Kv-BV for qemu-devel@archiver.kernel.org; Thu, 30 May 2019 15:18:42 -0400 Received: from eggs.gnu.org ([209.51.188.92]:59457) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hWQR6-00082v-Mq for qemu-devel@nongnu.org; Thu, 30 May 2019 15:10:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hWQR5-0000b6-Kq for qemu-devel@nongnu.org; Thu, 30 May 2019 15:10:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42904) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hWQR5-0000aI-Cr for qemu-devel@nongnu.org; Thu, 30 May 2019 15:09:59 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id B5003C0669AF for ; Thu, 30 May 2019 19:09:58 +0000 (UTC) Received: from work-vm (ovpn-117-91.ams2.redhat.com [10.36.117.91]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C36635D9E1; Thu, 30 May 2019 19:09:48 +0000 (UTC) Date: Thu, 30 May 2019 20:09:46 +0100 From: "Dr. David Alan Gilbert" To: Jens Freimann Message-ID: <20190530190945.GM2823@work-vm> References: <20190517125820.2885-1-jfreimann@redhat.com> <20190517125820.2885-4-jfreimann@redhat.com> <20190521094504.GB2915@work-vm> <20190530145645.tjwkgi4hae5yblsi@jenstp.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190530145645.tjwkgi4hae5yblsi@jenstp.localdomain> User-Agent: Mutt/1.11.4 (2019-03-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 30 May 2019 19:09:58 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 3/4] net/virtio: add failover support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pkrempa@redhat.com, berrange@redhat.com, ehabkost@redhat.com, mst@redhat.com, aadam@redhat.com, qemu-devel@nongnu.org, laine@redhat.com, ailan@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Jens Freimann (jfreimann@redhat.com) wrote: > Hi David, > > sorry for the delayed reply. > > On Tue, May 28, 2019 at 11:04:15AM -0400, Michael S. Tsirkin wrote: > > On Tue, May 21, 2019 at 10:45:05AM +0100, Dr. David Alan Gilbert wrote: > > > * Jens Freimann (jfreimann@redhat.com) wrote: > > > > +static void virtio_net_primary_plug_timer(void *opaque); > > > > + > > > > static void virtio_net_set_link_status(NetClientState *nc) > > > > { > > > > VirtIONet *n = qemu_get_nic_opaque(nc); > > > > @@ -786,6 +796,14 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features) > > > > } else { > > > > memset(n->vlans, 0xff, MAX_VLAN >> 3); > > > > } > > > > + > > > > + if (virtio_has_feature(features, VIRTIO_NET_F_STANDBY)) { > > > > + atomic_set(&n->primary_should_be_hidden, false); > > > > + if (n->primary_device_timer) > > > > + timer_mod(n->primary_device_timer, > > > > + qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + > > > > + 4000); > > > > + } > > > > > > What's this magic timer constant and why? > > To be honest it's a leftover from previous versions (before I took > over) of the patches and I'm not sure why the timer is there. > I removed it and so far see no reason to keep it. > > > > > > > > } > > > > > > > > static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd, > > > > @@ -2626,6 +2644,87 @@ void virtio_net_set_netclient_name(VirtIONet *n, const char *name, > > > > n->netclient_type = g_strdup(type); > > > > } > > > > > > > > +static void virtio_net_primary_plug_timer(void *opaque) > > > > +{ > > > > + VirtIONet *n = opaque; > > > > + Error *err = NULL; > > > > + > > > > + if (n->primary_device_dict) > > > > + n->primary_device_opts = qemu_opts_from_qdict(qemu_find_opts("device"), > > > > + n->primary_device_dict, &err); > > > > + if (n->primary_device_opts) { > > > > + n->primary_dev = qdev_device_add(n->primary_device_opts, &err); > > > > + error_setg(&err, "virtio_net: couldn't plug in primary device"); > > > > + return; > > > > + } > > > > + if (!n->primary_device_dict && err) { > > > > + if (n->primary_device_timer) { > > > > + timer_mod(n->primary_device_timer, > > > > + qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + > > > > + 100); > > > > > > same here. > > see above > > > > > > > > > > > + } > > > > + } > > > > +} > > > > + > > > > +static void virtio_net_handle_migration_primary(VirtIONet *n, > > > > + MigrationState *s) > > > > +{ > > > > + Error *err = NULL; > > > > + bool should_be_hidden = atomic_read(&n->primary_should_be_hidden); > > > > + > > > > + n->primary_dev = qdev_find_recursive(sysbus_get_default(), > > > > + n->primary_device_id); > > > > + if (!n->primary_dev) { > > > > + error_setg(&err, "virtio_net: couldn't find primary device"); > > > > > > There's something broken with the error handling in this function - the > > > 'err' never goes anywhere - I don't think it ever gets printed or > > > reported or stops the migration. > > yes, I'll fix it. > > > > > + } > > > > + if (migration_in_setup(s) && !should_be_hidden && n->primary_dev) { > > > > + qdev_unplug(n->primary_dev, &err); > > > > > > Not knowing unplug well; can you just explain - is that device hard > > > unplugged and it's gone by the time this function returns or is it still > > > hanging around for some indeterminate time? > > Qemu will trigger an unplug request via pcie attention button in which case > there could be a delay by the guest operating system. We could give it some > amount of time and if nothing happens try surpise removal or handle the > error otherwise. OK, can you show how one of those is going to work and try it out. THis setup is weird enough I just want to make sure it works. Dave > > regards, > Jens -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK