My cpu device is reported as available from clGetDeviceInfo. But when I try to clCreateContext, it returns error -2 (CL_DEVICE_NOT_AVAILABLE). The device is then reported as non-availble from clGetDeviceInfo.
I am running ubuntu 14.04 on virtualbox on Windows 7. From what I gathered, running in a VM is not an issue for OpenCL on a cpu. My cpu is an i5-2520m.
There might be a solution (http://stackoverflow.com/questions/18193320 and http://stackoverflow.com/questions/17346647), but I thought I would try this forum first. The solution in those posts is to install the AMD graphics driver, even if one does not have an AMD video card.