reportviwer works with entity Framework? How?
You may want to consider checking out Beth Massi's blog post on using the ReportViewer with ADO.NET Services and Entity Framework. I'd recommend looking at this other post on using the ReportViewer in ASP.NET 4.0 with Entity Framework as well.
I wish I could provide more insight than just some links, but I really haven't used the two technologies with one another.