From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933583AbcFMOg2 (ORCPT ); Mon, 13 Jun 2016 10:36:28 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:45306 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933485AbcFMOgZ (ORCPT ); Mon, 13 Jun 2016 10:36:25 -0400 X-IBM-Helo: d06dlp03.portsmouth.uk.ibm.com X-IBM-MailFrom: cornelia.huck@de.ibm.com X-IBM-RcptTo: kvm@vger.kernel.org;linux-kernel@vger.kernel.org Date: Mon, 13 Jun 2016 16:36:14 +0200 From: Cornelia Huck To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Christian Borntraeger Subject: Re: [PATCH 3/3] KVM: s390: use kvm->created_vcpus In-Reply-To: <1465824332-10628-4-git-send-email-pbonzini@redhat.com> References: <1465824332-10628-1-git-send-email-pbonzini@redhat.com> <1465824332-10628-4-git-send-email-pbonzini@redhat.com> Organization: IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz =?UTF-8?B?R2VzY2jDpGZ0c2bDvGhydW5nOg==?= Dirk Wittkopp Sitz der Gesellschaft: =?UTF-8?B?QsO2Ymxpbmdlbg==?= Registergericht: Amtsgericht Stuttgart, HRB 243294 X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16061314-0016-0000-0000-000001F728F6 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16061314-0017-0000-0000-000021E6A41E Message-Id: <20160613163614.25256af8.cornelia.huck@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-13_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1606130164 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 13 Jun 2016 15:25:32 +0200 Paolo Bonzini wrote: > The new created_vcpus field avoids possible races between enabling > capabilities and creating VCPUs. > > Signed-off-by: Paolo Bonzini > --- > arch/s390/kvm/kvm-s390.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > @@ -426,7 +426,7 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att > ret = -EBUSY; > VM_EVENT(kvm, 3, "%s", "ENABLE: CMMA support"); > mutex_lock(&kvm->lock); > - if (atomic_read(&kvm->online_vcpus) == 0) { > + if (kvm->created_vcpus) { if (!kvm->created_vcpus) { > kvm->arch.use_cmma = 1; > ret = 0; > } > @@ -467,7 +467,7 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att > > ret = -EBUSY; > mutex_lock(&kvm->lock); > - if (atomic_read(&kvm->online_vcpus) == 0) { > + if (kvm->created_vcpus) { dito > /* gmap_alloc will round the limit up */ > struct gmap *new = gmap_alloc(current->mm, new_limit); >