From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48373) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpepb-0001Tw-UU for qemu-devel@nongnu.org; Wed, 06 Sep 2017 14:13:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dpepX-0003er-UE for qemu-devel@nongnu.org; Wed, 06 Sep 2017 14:13:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54225 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dpepX-0003ed-O8 for qemu-devel@nongnu.org; Wed, 06 Sep 2017 14:13:39 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v86I8m2U062807 for ; Wed, 6 Sep 2017 14:13:39 -0400 Received: from e19.ny.us.ibm.com (e19.ny.us.ibm.com [129.33.205.209]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cth6xpbw3-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 06 Sep 2017 14:13:38 -0400 Received: from localhost by e19.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Sep 2017 14:13:38 -0400 References: <20170904154316.4148-1-david@redhat.com> <20170904154316.4148-18-david@redhat.com> From: Matthew Rosato Date: Wed, 6 Sep 2017 14:13:34 -0400 MIME-Version: 1.0 In-Reply-To: <20170904154316.4148-18-david@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: <40d23c4e-2761-24ae-5f5a-3db9b478ffd2@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH v2 17/19] s390x: CPU hot unplug via device_del cannot work List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand , qemu-devel@nongnu.org Cc: thuth@redhat.com, Eduardo Habkost , cohuck@redhat.com, Richard Henderson , Alexander Graf , borntraeger@de.ibm.com On 09/04/2017 11:43 AM, David Hildenbrand wrote: > device_del on a CPU will currently do nothing. Let's emmit an error > telling that this is will never work (there is no architecture support > on s390x). Error message copied from ppc. > > (qemu) device_del cpu1 > device_del cpu1 > CPU hot unplug not supported on this machine > > Signed-off-by: David Hildenbrand Architecture discussions aside, this code will work as-is to prevent CPU unplug. Add "currently" as Christian suggests and: Reviewed-by: Matthew Rosato > --- > hw/s390x/s390-virtio-ccw.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c > index 22a8a1b45d..dd149567bb 100644 > --- a/hw/s390x/s390-virtio-ccw.c > +++ b/hw/s390x/s390-virtio-ccw.c > @@ -338,6 +338,15 @@ static void s390_machine_device_plug(HotplugHandler *hotplug_dev, > } > } > > +static void s390_machine_device_unplug_request(HotplugHandler *hotplug_dev, > + DeviceState *dev, Error **errp) > +{ > + if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) { > + error_setg(errp, "CPU hot unplug not supported on this machine"); > + return; > + } > +} > + > static HotplugHandler *s390_get_hotplug_handler(MachineState *machine, > DeviceState *dev) > { > @@ -387,6 +396,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data) > mc->max_cpus = 248; > mc->get_hotplug_handler = s390_get_hotplug_handler; > hc->plug = s390_machine_device_plug; > + hc->unplug_request = s390_machine_device_unplug_request; > nc->nmi_monitor_handler = s390_nmi; > } >