First of all, how long has this white smoke issue been around? How much smoke is there and does it go away or remain as you drive? If it has been around for a while you should notice a reduction in your anti freeze level in the rad. Also, if it is a defective head gasket (typical reason), compression pressure might pressurize the rad forcing anti freeze out into the overflow tank along with some bubbling. Often when diagnosing a white smoke issue coming out of the exhaust, you can taste the anti freeze in the smoke, a sure sign you have an internal anti freeze leak. If that is taking place, pull the spark plugs to see which ones are discoloured.
Was the bike ever overheated? Highly doubt you have a valve guide issue.
If the white smoke is there for only a few minutes during start up, I agree with Claviger.... condensation.