Android emulator and virtualbox cannot run at same

Whenever I have Virtualbox running, I cannot start an Android emulator image (and vice versa). The error message in the AVD manager is

ioctl(KVM_CREATE_VM) failed: Device or resource busy
ko:failed to initialize KVM

How can I make both run at the same time?

That is a Ubuntu 64 bit, all involved software is of the latest released version.

I had the same problem on Ubuntu 13.10. Try to remove kvm and kvm_intel kernel modules.

To do this:

1. Stop all emulators.

2. Run command: 'sudo rmmod kvm_intel kvm'

Without these kernel modules Virtualbox and Android emulators can work at the same time.

BTW, I do not know why the modules are loaded.