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/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
index c595957983..9b0349922e 100644
--- a/hw/virtio/vhost-user-fs.c
+++ b/hw/virtio/vhost-user-fs.c
@@ -161,6 +161,9 @@ static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx,
 {
     VHostUserFS *fs = VHOST_USER_FS(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
     vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask);
 }
 
@@ -168,6 +171,9 @@ static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx)
 {
     VHostUserFS *fs = VHOST_USER_FS(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_virtqueue_pending(&fs->vhost_dev, idx);
 }