4 files changed, 24 insertions, 0 deletions

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index d8ddbba6fe7d..f5104b7c52cd 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1172,6 +1172,11 @@ out:
 
 #define PALE_RESET_ENTRY    0x80000000ffffffb0UL
 
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu)
+{
+        return irqchip_in_kernel(vcpu->kcm) == (vcpu->arch.apic != NULL);
+}
+
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
         struct kvm_vcpu *v;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 03a1fd47a6d3..9477dc6cccae 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3199,6 +3199,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 r = -EEXIST;
                 if (kvm->arch.vpic)
                         goto create_irqchip_unlock;
+                r = -EINVAL;
+                if (atomic_read(&kvm->online_vcpus))
+                        goto create_irqchip_unlock;
                 r = -ENOMEM;
                 vpic = kvm_create_pic(kvm);
                 if (vpic) {
@@ -6107,6 +6110,11 @@ void kvm_arch_check_processor_compat(void *rtn)
         kvm_x86_ops->check_processor_compatibility(rtn);
 }
 
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu)
+{
+        return irqchip_in_kernel(vcpu->kvm) == (vcpu->arch.apic != NULL);
+}
+
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
         struct page *page;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 355e44555c39..e42d85ae8541 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -805,6 +805,13 @@ static inline bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
 {
         return vcpu->kvm->bsp_vcpu_id == vcpu->vcpu_id;
 }
+
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu);
+
+#else
+
+static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
+
 #endif
 
 #ifdef __KVM_HAVE_DEVICE_ASSIGNMENT
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e4431ada5947..94e148e38719 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1651,6 +1651,10 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
                 goto vcpu_destroy;
 
         mutex_lock(&kvm->lock);
+        if (!kvm_vcpu_compatible(vcpu)) {
+                r = -EINVAL;
+                goto unlock_vcpu_destroy;
+        }
         if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
                 r = -EINVAL;
                 goto unlock_vcpu_destroy;