From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754794Ab2K1MxY (ORCPT ); Wed, 28 Nov 2012 07:53:24 -0500 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:60437 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754475Ab2K1MxW (ORCPT ); Wed, 28 Nov 2012 07:53:22 -0500 Message-ID: <50B6093B.7040404@linux.vnet.ibm.com> Date: Wed, 28 Nov 2012 20:53:15 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , Gleb Natapov , LKML , KVM Subject: [PATCH 1/2] KVM: VMX: fix invalid cpu passed to smp_call_function_single Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12112812-1396-0000-0000-00000239EB51 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In loaded_vmcs_clear, loaded_vmcs->cpu is the fist parameter passed to smp_call_function_single, if the target cpu is downing (doing cpu hot remove), loaded_vmcs->cpu can become -1 then -1 is passed to smp_call_function_single It can be triggered when vcpu is being destroyed, loaded_vmcs_clear is called in the preemptionable context Signed-off-by: Xiao Guangrong --- arch/x86/kvm/vmx.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6599e45..29e8f42 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1007,9 +1007,11 @@ static void __loaded_vmcs_clear(void *arg) static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs) { - if (loaded_vmcs->cpu != -1) - smp_call_function_single( - loaded_vmcs->cpu, __loaded_vmcs_clear, loaded_vmcs, 1); + int cpu = loaded_vmcs->cpu; + + if (cpu != -1) + smp_call_function_single(cpu, + __loaded_vmcs_clear, loaded_vmcs, 1); } static inline void vpid_sync_vcpu_single(struct vcpu_vmx *vmx) -- 1.7.7.6