virtio-net: add support for configure interrupt

Add functions to support configure interrupt in virtio_net
The functions are config_pending and config_mask, while
this input idx is VIRTIO_CONFIG_IRQ_IDX will check the
function of configure interrupt.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-9-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/net/vhost_net-stub.c

@@ -101,3 +101,12 @@ int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
 {
     return 0;
 }
+
+bool vhost_net_config_pending(VHostNetState *net)
+{
+    return false;
+}
+
+void vhost_net_config_mask(VHostNetState *net, VirtIODevice *dev, bool mask)
+{
+}

hw/net/vhost_net.c

@@ -457,6 +457,15 @@ void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 }
 
+bool vhost_net_config_pending(VHostNetState *net)
+{
+    return vhost_config_pending(&net->dev);
+}
+
+void vhost_net_config_mask(VHostNetState *net, VirtIODevice *dev, bool mask)
+{
+    vhost_config_mask(&net->dev, dev, mask);
+}
 VHostNetState *get_vhost_net(NetClientState *nc)
 {
     VHostNetState *vhost_net = 0;

hw/net/virtio-net.c

@@ -3169,7 +3169,7 @@ static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
-        return false;
+        return vhost_net_config_pending(get_vhost_net(nc->peer));
     }
     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
 }
@@ -3181,9 +3181,9 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        vhost_net_config_mask(get_vhost_net(nc->peer), vdev, mask);
         return;
     }
-
     vhost_net_virtqueue_mask(get_vhost_net(nc->peer), vdev, idx, mask);
 }
 

include/net/vhost_net.h

@@ -39,6 +39,8 @@ int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
 bool vhost_net_virtqueue_pending(VHostNetState *net, int n);
 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask);
+bool vhost_net_config_pending(VHostNetState *net);
+void vhost_net_config_mask(VHostNetState *net, VirtIODevice *dev, bool mask);
 int vhost_net_notify_migration_done(VHostNetState *net, char* mac_addr);
 VHostNetState *get_vhost_net(NetClientState *nc);