virtio: introduce macro VIRTIO_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: <20221222070451.936503-2-lulu@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 20 insertions, 2 deletions

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index b342d66160..0bfe454c23 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3325,6 +3325,15 @@ static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
     } else {
         nc = qemu_get_subqueue(n->nic, vq2q(idx));
     }
+    /*
+     * Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
+     * as the Marco of configure interrupt's IDX, If this driver does not
+     * support, the function will return false
+     */
+
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
 }
 
@@ -3348,8 +3357,17 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
     } else {
         nc = qemu_get_subqueue(n->nic, vq2q(idx));
     }
-    vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
-                             vdev, idx, mask);
+    /*
+     *Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
+     * as the Marco of configure interrupt's IDX, If this driver does not
+     * support, the function will return
+     */
+
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
+
+    vhost_net_virtqueue_mask(get_vhost_net(nc->peer), vdev, idx, mask);
 }
 
 static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)