[RFC 6/8] virtio-ccw: Lock ioeventfd state with VIRTIO_F_NOTIFICATION_DATA

[Jonah Palmer]

Prevent ioeventfd from being enabled/disabled when a virtio-ccw device
has negotiated the VIRTIO_F_NOTIFICATION_DATA transport feature.

Due to the ioeventfd not being able to carry the extra data associated
with this feature, the ioeventfd should be left in a disabled state for
emulated virtio-ccw devices using this feature.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
---
 hw/s390x/virtio-ccw.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index b4676909dd..936ba78fda 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -530,14 +530,16 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             if (ret) {
                 break;
             }
-            if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+            if (!(status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+                !virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
                 virtio_ccw_stop_ioeventfd(dev);
             }
             if (virtio_set_status(vdev, status) == 0) {
                 if (vdev->status == 0) {
                     virtio_ccw_reset_virtio(dev);
                 }
-                if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
+                if ((status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+                    !virtio_vdev_has_feature(vdev, 
VIRTIO_F_NOTIFICATION_DATA)) {
                     virtio_ccw_start_ioeventfd(dev);
                 }
                 sch->curr_status.scsw.count = ccw.count - sizeof(status);
-- 
2.39.3