[PATCH v3 2/3] vfio/pci: Fix a segfault in vfio_realize

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

In case irqchip_change_notifier isn't added, removing it triggers segfault.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/vfio/pci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index c71b0955d81c..82c4cf4f7609 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3222,7 +3222,9 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
 out_deregister:
     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
-    kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier);
+    if (vdev->irqchip_change_notifier.notify) {
+        kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier);
+    }
 out_teardown:
     vfio_teardown_msi(vdev);
     vfio_bars_exit(vdev);
-- 
2.34.1