Some embodiments of the inventive subject matter are directed to receiving a request from a first instance of an operating system (e.g., a virtual operating system) to load a kernel extension that extends functionality of a kernel, where the kernel and the first instance of the operating system are managed by a second instance of the operating system (e.g., a global operating system), and where the first and second instances of the operating system share the kernel. Some embodiments are further directed to loading the kernel extension as a shared kernel extension. Some embodiments are further directed to receiving a request by the first instances of the operating system to unload the kernel extension and determining that a third instance of the operating system (e.g., another virtual operating system also managed by the global operating system) requires the kernel extension to remain loaded. Some embodiments are further directed to notifying the first instance of the operating system that the kernel extension was unloaded while leaving the kernel extension loaded in the kernel.