Re: [PATCH net,1/1] hyperv: Add support for setting MAC from within guests

On Fri, 2012-07-06 at 14:25 -0700, Haiyang Zhang wrote:

This adds support for setting synthetic NIC MAC address from within Linux
guests. Before using this feature, the option "spoofing of MAC address"
should be enabled at the Hyper-V manager / Settings of the synthetic
NIC.

[...]

+int rndis_filter_set_device_mac(struct hv_device *hdev, char *mac)
+{

[...]

+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		netdev_err(ndev, "timeout before we got a set response...\n");
+		/*
+		 * can't put_rndis_request, since we may still receive a
+		 * send-completion.
+		 */
+		return -EBUSY;
+	} else {
+		set_complete = &request->response_msg.msg.set_complete;
+		if (set_complete->status != RNDIS_STATUS_SUCCESS)
+			ret = -EINVAL;

[...]

Is there a specific error code that indicates the hypervisor is
configured not to allow MAC address changes?  If so, shouldn't that be
translated to return EPERM rather than EINVAL?

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.