From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33200) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZvonZ-0005Nu-72 for qemu-devel@nongnu.org; Mon, 09 Nov 2015 10:56:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZvonV-0004YS-W1 for qemu-devel@nongnu.org; Mon, 09 Nov 2015 10:56:01 -0500 Received: from e06smtp05.uk.ibm.com ([195.75.94.101]:36595) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZvonV-0004YC-NI for qemu-devel@nongnu.org; Mon, 09 Nov 2015 10:55:57 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 9 Nov 2015 15:55:54 -0000 Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 4337D219005F for ; Mon, 9 Nov 2015 15:55:48 +0000 (GMT) Received: from d06av02.portsmouth.uk.ibm.com (d06av02.portsmouth.uk.ibm.com [9.149.37.228]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tA9FtqHm4981092 for ; Mon, 9 Nov 2015 15:55:52 GMT Received: from d06av02.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av02.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tA9Ftqqq025307 for ; Mon, 9 Nov 2015 08:55:52 -0700 References: <1447082260-427-1-git-send-email-mjrosato@linux.vnet.ibm.com> <5640BBAA.1000201@suse.de> <5640BD5B.9050204@de.ibm.com> <5640BDD2.9040102@de.ibm.com> From: Christian Borntraeger Message-ID: <5640C207.70304@de.ibm.com> Date: Mon, 9 Nov 2015 16:55:51 +0100 MIME-Version: 1.0 In-Reply-To: <5640BDD2.9040102@de.ibm.com> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 0/4] s390: Allow hotplug of s390 CPUs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?Andreas_F=c3=a4rber?= , Matthew Rosato , qemu-devel@nongnu.org Cc: cornelia.huck@de.ibm.com, agraf@suse.de, rth@twiddle.net Am 09.11.2015 um 16:37 schrieb Christian Borntraeger: > Am 09.11.2015 um 16:35 schrieb Christian Borntraeger: >> Am 09.11.2015 um 16:28 schrieb Andreas Färber: >>> Hi, >>> >>> Am 09.11.2015 um 16:17 schrieb Matthew Rosato: >>>> To subsequently hotplug a CPU: >>>> >>>> Issue 'cpu-add ' from qemu monitor, or use virsh setvcpus --count >>>> , where is the total number of desired guest CPUs. >>> >>> What exactly is still missing for you to use the standard device_add? >>> >>> Last time I checked (a while ago...) some patches were stuck on the x86 >>> side, and I don't recall hearing any feedback from the s390x side in my >>> KVM Forum CPU hotplug session. >> >> libvirt uses "cpu-add" unconditionally for hotplugging, so we certainly >> want to support that. > > Sorry, hit send too early. I assume you want us to support device_add of > a CPU in addition to that. Correct? I just did a quick test with Matts patch. after applying diff --git a/qom/cpu.c b/qom/cpu.c index fb80d13..8152744 100644 --- a/qom/cpu.c +++ b/qom/cpu.c @@ -360,7 +360,7 @@ static void cpu_class_init(ObjectClass *klass, void *data) * Reason: CPUs still need special care by board code: wiring up * IRQs, adding reset handlers, halting non-first CPUs, ... */ - dc->cannot_instantiate_with_device_add_yet = true; +// dc->cannot_instantiate_with_device_add_yet = true; } static const TypeInfo cpu_type_info = { I was able to use device_add s390-cpu but no comprehensive testing was done. I was even able to add more cpus than maxcpus, but the guest could not make use of it. Fix is probably easy. But in general it looks like that we _could_ enable device_add for CPUs as soon as others are ready as well. Matt, do you agree? Christian