The equation is a circluar cylindar of radius 1 centered on the y axis. It's bottom is the xz plane(y=0) and it is cut by the plane .
To find the volume I want to use cylindrical coordinates, but since the cylindar is tipped over lets use this change of coordinates.
Now we get the integral
You could have also set up a double integral using the same idea where y is your height function.
I hope this helps.