[PATCH v2 4/9] vfio/ap: Clear error object pointer after non-fatal errors

[Eric Farman <farman@linux.ibm.com>]

Registering a new IRQ notifier will allocate an error object if needed,
and warn_report_err() will release that memory once it's finished.
The pointer remains, however, so subsequent errors after the non-fatal
errors in vfio_ap_realize() would cause an assertion failure for a
non-NULL pointer.

Fix this by clearing the pointer once the warning has been reported,
to reset the state of the error objects.

Cc: Anthony Krowiak <akrowiak@linux.ibm.com>
Cc: qemu-stable@nongnu.org
Fixes: 1360b2ad1f ("s390x/ap: Wire up the device request notifier interface")
Fixes: 0fb8a62fe4 ("hw/vfio/ap: notification handler for AP config changed event")
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 hw/vfio/ap.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 6e2a1223ea..2926e04ad4 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -247,8 +247,10 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
         /*
          * Report this error, but do not make it a failing condition.
          * Lack of this IRQ in the host does not prevent normal operation.
+         * Clear the pointer, since the warning will release it.
          */
         warn_report_err(err);
+        err = NULL;
     }
 
     if (!vfio_ap_register_irq_notifier(vapdev, VFIO_AP_CFG_CHG_IRQ_INDEX, &err))
@@ -256,8 +258,10 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
         /*
          * Report this error, but do not make it a failing condition.
          * Lack of this IRQ in the host does not prevent normal operation.
+         * Clear the pointer, since the warning will release it.
          */
         warn_report_err(err);
+        err = NULL;
     }
 
     return;
-- 
2.53.0