Drivers: hv: balloon: Disable hot add when CONFIG_MEMORY_HOTPLUG is not set

If the guest does not support memory hotplugging, it should respond to
the host with zero pages added and successful result code. This signals
to the host that hotplugging is not supported and the host will avoid
sending future hot-add requests.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/hv_balloon.c

@@ -1501,7 +1501,11 @@ static int balloon_probe(struct hv_device *dev,
 	struct dm_version_request version_req;
 	struct dm_capabilities cap_msg;
 
+#ifdef CONFIG_MEMORY_HOTPLUG
 	do_hot_add = hot_add;
+#else
+	do_hot_add = false;
+#endif
 
 	/*
 	 * First allocate a send buffer.