diff options
| -rw-r--r-- | include/linux/kvm_host.h | 4 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 5 |
2 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bd1097a95704..81089cf1f0c1 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -427,6 +427,10 @@ struct kvm { static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i) { + /* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case + * the caller has read kvm->online_vcpus before (as is the case + * for kvm_for_each_vcpu, for example). + */ smp_rmb(); return kvm->vcpus[i]; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 8dc4828f623f..d8db2f8fce9c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2206,6 +2206,11 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) } kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu; + + /* + * Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus + * before kvm->online_vcpu's incremented value. + */ smp_wmb(); atomic_inc(&kvm->online_vcpus); |