+static int iavf_emu_update_status(int vfio_dev_id) {
+	struct iavf_emudev *dev;
+	int ret;
+
+	dev = find_iavf_with_dev_id(vfio_dev_id);
+	if (!dev)
+		return -1;
+
+	ret = iavf_emu_setup_mem_table(dev);
+	if (ret) {
+		EMU_IAVF_LOG(ERR, "Failed to set up memtable for "
+			"device %d", dev->vfio->dev_id);
+		return ret;
+	}
+
+	ret = iavf_emu_setup_irq(dev);

In update callback, irq fds will be reinitialized here. Think about if the update happening during mailbox communication, the eventfd of mailbox will be cleared without notify.

+	if (ret) {
+		EMU_IAVF_LOG(ERR, "Failed to set up irq for "
+			"device %d", dev->vfio->dev_id);
+		return ret;
+	}
+
+	dev->ops->update_status(dev->edev);
+
+	return 0;
+}