Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752696AbcDUOPY (ORCPT ); Thu, 21 Apr 2016 10:15:24 -0400 Received: from e06smtp08.uk.ibm.com ([195.75.94.104]:55760 "EHLO e06smtp08.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752315AbcDUOPW (ORCPT ); Thu, 21 Apr 2016 10:15:22 -0400 X-IBM-Helo: d06dlp03.portsmouth.uk.ibm.com X-IBM-MailFrom: gkurz@linux.vnet.ibm.com X-IBM-RcptTo: david@gibson.dropbear.id.au;james.hogan@imgtec.com;linux-mips@linux-mips.org;qemu-ppc@nongnu.org;mingo@redhat.com;pbonzini@redhat.com;rkrcmar@redhat.com;paulus@samba.org;kvm@vger.kernel.org;linux-kernel@vger.kernel.org Subject: [PATCH v4 1/2] KVM: remove NULL return path for vcpu ids >= KVM_MAX_VCPUS From: Greg Kurz To: Paolo Bonzini , james.hogan@imgtec.com, mingo@redhat.com Cc: linux-mips@linux-mips.org, kvm@vger.kernel.org, rkrcmar@redhat.com, linux-kernel@vger.kernel.org, David Hildenbrand , qemu-ppc@nongnu.org, Cornelia Huck , Paul Mackerras , David Gibson Date: Thu, 21 Apr 2016 16:15:05 +0200 Message-ID: <146124810201.32509.2946887043729554992.stgit@bahia.huguette.org> In-Reply-To: <146124809455.32509.15232948272580716135.stgit@bahia.huguette.org> References: <146124809455.32509.15232948272580716135.stgit@bahia.huguette.org> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16042114-0033-0000-0000-000012611B53 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1182 Lines: 34 Commit c896939f7cff ("KVM: use heuristic for fast VCPU lookup by id") added a return path that prevents vcpu ids to exceed KVM_MAX_VCPUS. This is a problem for powerpc where vcpu ids can grow up to 8*KVM_MAX_VCPUS. This patch simply reverses the logic so that we only try fast path if the vcpu id can be tried as an index in kvm->vcpus[]. The slow path is not affected by the change. Signed-off-by: Greg Kurz --- include/linux/kvm_host.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 5276fe0916fc..23bfe1bd159c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -447,12 +447,13 @@ static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i) static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id) { - struct kvm_vcpu *vcpu; + struct kvm_vcpu *vcpu = NULL; int i; - if (id < 0 || id >= KVM_MAX_VCPUS) + if (id < 0) return NULL; - vcpu = kvm_get_vcpu(kvm, id); + if (id < KVM_MAX_VCPUS) + vcpu = kvm_get_vcpu(kvm, id); if (vcpu && vcpu->vcpu_id == id) return vcpu; kvm_for_each_vcpu(i, vcpu, kvm)