Hello there, Welcome to the site. I must must admit I haven't noticed any knocking sound.Bike rides and performs great. Is the slight "knocking" sound normal when accelerating moderately through the low gears? The sound is definitely not a pinging sound. Probably just the engine doing its work.
At what RPMs are you hearing it?
You know the SV650 doesn't like too much throttle under 3500-4000 rpm. It protests by knocking/bucking.