So… Do you not realize that you aren’t allowed to do this? The EULA for El Capitan requires that virtualized instances be run on Apple hardware.
See for yourself: http://images.apple.com/legal/sla/docs/OSX1011.pdf (Section 2: subsections A, B, C)
By purchasing the OS directly (as opposed to getting it preinstalled), you are granted a license to “(iii) to install, use and run up to two (2) additional copies or instances of the Apple Software within virtual operating system environments on each Mac Computer you own or control that is already running the Apple Software, for purposes of: (a) software development; (b) testing during software development; © using OS X Server; or (d) personal, noncommercial use.”
The license only gives you permission to install VMs “on each Mac Computer you own or control that is already running the Apple Software”.