virtio: introduce macro IRTIO_CONFIG_IRQ_IDX

To support configure interrupt for vhost-vdpa
Introduce VIRTIO_CONFIG_IRQ_IDX -1 as configure interrupt's queue index,
Then we can reuse the functions guest_notifier_mask and guest_notifier_pending.
Add the check of queue index in these drivers, if the driver does not support
configure interrupt, the function will just return

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-2-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
index 09818231bd..d4a440e815 100644
--- a/hw/display/vhost-user-gpu.c
+++ b/hw/display/vhost-user-gpu.c
@@ -485,6 +485,9 @@ vhost_user_gpu_guest_notifier_pending(VirtIODevice *vdev, int idx)
 {
     VhostUserGPU *g = VHOST_USER_GPU(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_virtqueue_pending(&g->vhost->dev, idx);
 }
 
@@ -493,6 +496,9 @@ vhost_user_gpu_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
 {
     VhostUserGPU *g = VHOST_USER_GPU(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
     vhost_virtqueue_mask(&g->vhost->dev, vdev, idx, mask);
 }