From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965486AbcFMNZj (ORCPT ); Mon, 13 Jun 2016 09:25:39 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36128 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965437AbcFMNZh (ORCPT ); Mon, 13 Jun 2016 09:25:37 -0400 From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Cornelia Huck , Christian Borntraeger Subject: [PATCH 0/3] KVM: do not use kvm->online_vcpus to check "has one VCPU been created?" Date: Mon, 13 Jun 2016 15:25:29 +0200 Message-Id: <1465824332-10628-1-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kvm->online_vcpus is only updated at the very end of KVM_CREATE_VCPU. Thus, it can be racy to use it as a check for "has any VCPU been created already?". While x86 detects the race through kvm_vcpu_compatible, it is kinda hackish and s390 does not do anything similar. Provide a better fix for both. Paolo Bonzini (3): KVM: introduce created_vcpus KVM: remove kvm_vcpu_compatible KVM: s390: use created_vcpus arch/s390/kvm/kvm-s390.c | 10 +++++----- arch/x86/kvm/Kconfig | 1 - arch/x86/kvm/x86.c | 11 +++-------- include/linux/kvm_host.h | 14 ++++++++------ virt/kvm/Kconfig | 3 --- virt/kvm/kvm_main.c | 27 +++++++++++++++++---------- 6 files changed, 33 insertions(+), 33 deletions(-) -- 1.8.3.1