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 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html