[RFC 2/8] virtio-pci: Lock ioeventfd state with VIRTIO_F_NOTIFICATION_DATA

[Jonah Palmer]

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

Due to 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-pci devices using this feature.

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

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index c7c577b177..fd9717a0f5 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -420,13 +420,15 @@ static void virtio_ioport_write(void *opaque, uint32_t 
addr, uint32_t val)
         }
         break;
     case VIRTIO_PCI_STATUS:
-        if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        if (!(val & VIRTIO_CONFIG_S_DRIVER_OK) &&
+            !virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
             virtio_pci_stop_ioeventfd(proxy);
         }
 
         virtio_set_status(vdev, val & 0xFF);
 
-        if (val & VIRTIO_CONFIG_S_DRIVER_OK) {
+        if ((val & VIRTIO_CONFIG_S_DRIVER_OK) &&
+            !virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
             virtio_pci_start_ioeventfd(proxy);
         }
 
-- 
2.39.3