在 2021/3/15 下午3:45, Zhu Lingshan 写道:

  static u32 ifcvf_vdpa_get_device_id(struct vdpa_device *vdpa_dev)
  {
-	return VIRTIO_ID_NET;
+	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+	u32 ret = -EOPNOTSUPP;
+
+	if (ifcvf_probed_virtio_net(vf))
+		ret = VIRTIO_ID_NET;

So the point is to simplify the future extension.

How about simply?

if (device_id>0x1040)
     return devce_id - 0x1040;
else
     return device_id;

Since I don't think you plan to introduce device whose vendor id is not 
1AF4 and the subsys vendor/device id is not interesting to vDPA bus.

Thanks

+
+	return ret;
  }