When running a multi-gpu program it is very important that each process or cpu thread picks the right devices. SYCL provides several function to check the visible devices. For example the get_devices which is part of the sycl::devices namespace can obtain the list of devices which follow a specific criteria. With the argument sycl::info::device_type::gpu it will list all device which have the device_type property gpu. Similarly one can get the available CPU using the keyword cpuas argument.
A complete code is shown in the enumerate_device.cpp.