1 files changed, 2 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8361662e7e0a..f1e2e8c373c6 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2274,10 +2274,12 @@ static long kvm_vm_ioctl(struct file *filp,
 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
         case KVM_SET_BOOT_CPU_ID:
                 r = 0;
+                mutex_lock(&kvm->lock);
                 if (atomic_read(&kvm->online_vcpus) != 0)
                         r = -EBUSY;
                 else
                         kvm->bsp_vcpu_id = arg;
+                mutex_unlock(&kvm->lock);
                 break;
 #endif
         default: