KVM: only clear irq_source_id if irqchip is present

Otherwise kvm might attempt to dereference a NULL pointer.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 0d454d352717..9b077342ab54 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -243,6 +243,10 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
                 goto unlock;
         }
+        clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
+        if (!irqchip_in_kernel(kvm))
+                goto unlock;
+
         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) {
                 clear_bit(irq_source_id, &kvm->arch.vioapic->irq_states[i]);
                 if (i >= 16)
@@ -251,7 +255,6 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
                 clear_bit(irq_source_id, &pic_irqchip(kvm)->irq_states[i]);
 #endif
         }
-        clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 unlock:
         mutex_unlock(&kvm->irq_lock);
 }