[Qemu-devel] [PATCH 01/30] virtio-ccw: move virtio_ccw_stop_ioeventfd to virtio_ccw_busdev_unplug

[Paolo Bonzini <pbonzini@redhat.com>]

Similar to the PCI bug that prompted these patches, virtio-ccw will
segfault after the reworking of hotplug/hot-unplug.  Prepare for
this by moving virtio_ccw_stop_ioeventfd to before the freeing
of the proxy device.

A better place for this could be the device_unplugged callback
for the virtio-ccw bus.  However, we do not yet have a callback
that works: this patch avoids the problem while leaving the tree
bisectable.

Cc: qemu-stable@nongnu.org
Reported-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Suggested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/s390x/virtio-ccw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index f93a81c..e8b4547 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -631,7 +631,6 @@ static int virtio_ccw_exit(VirtioCcwDevice *dev)
 {
     SubchDev *sch = dev->sch;
 
-    virtio_ccw_stop_ioeventfd(dev);
     if (sch) {
         css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
         g_free(sch);
@@ -1228,6 +1227,8 @@ static int virtio_ccw_busdev_unplug(DeviceState *dev)
     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
     SubchDev *sch = _dev->sch;
 
+    virtio_ccw_stop_ioeventfd(_dev);
+
     /*
      * We should arrive here only for device_del, since we don't support
      * direct hot(un)plug of channels, but only through virtio.
-- 
1.8.3.1