From 0446f8121723b134ca1d1ed0b73e96d4a0a8689d Mon Sep 17 00:00:00 2001

From: Peter Xu <peterx@redhat.com>

Date: Mon, 6 Jan 2020 13:34:45 -0700

Subject: [PATCH] vfio/pci: Don't remove irqchip notifier if not registered

The kvm irqchip notifier is only registered if the device supports

INTx, however it's unconditionally removed.  If the assigned device

does not support INTx, this will cause QEMU to crash when unplugging

the device from the system.  Change it to conditionally remove the

notifier only if the notify hook is setup.

CC: Eduardo Habkost <ehabkost@redhat.com>

CC: David Gibson <david@gibson.dropbear.id.au>

CC: Alex Williamson <alex.williamson@redhat.com>

Cc: qemu-stable@nongnu.org # v4.2

Reported-by: yanghliu@redhat.com

Debugged-by: Eduardo Habkost <ehabkost@redhat.com>

Fixes: c5478fea27ac ("vfio/pci: Respond to KVM irqchip change notifier")

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1782678

Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

Reviewed-by: Greg Kurz <groug@kaod.org>

Signed-off-by: Alex Williamson <alex.williamson@redhat.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 2d40b396f2..337a173ce7 100644

--- a/hw/vfio/pci.c

+++ b/hw/vfio/pci.c

@@ -3076,7 +3076,9 @@ static void vfio_exitfn(PCIDevice *pdev)

     vfio_unregister_req_notifier(vdev);

     vfio_unregister_err_notifier(vdev);

     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);

+    }

     vfio_disable_interrupts(vdev);

     if (vdev->intx.mmap_timer) {

         timer_free(vdev->intx.mmap_timer);

-- 

2.25.1