Cylinder Question--Damaged???

Doing the top-end on my '99 rm250. The piston came out with some pretty good grooving on the intake side. Looking at the cylinder, it is fine except for the intake ports seem to be more of a sharp edge where they enter the cylinder than a rounded-off hole. Can this just be smoothed off with a file (right on the edge only, of course), or do I have a real problem here?

Thanks for any info.