KVM: x86: disallow multiple KVM_CREATE_IRQCHIP

Otherwise kvm will leak memory on multiple KVM_CREATE_IRQCHIP.
Also serialize multiple accesses with kvm->lock.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index c025a2362aae..be399e207d57 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -86,7 +86,11 @@ static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
 
 static inline int irqchip_in_kernel(struct kvm *kvm)
 {
-        return pic_irqchip(kvm) != NULL;
+        int ret;
+
+        ret = (pic_irqchip(kvm) != NULL);
+        smp_rmb();
+        return ret;
 }
 
 void kvm_pic_reset(struct kvm_kpic_state *s);