Systems and methods are provided for emulating guest code by a virtual machine function. An example method includes detecting, by a hypervisor, a request by a guest to access a resource. The guest includes a virtual machine function and kernel code, and runs on a virtual machine. The virtual machine and the hypervisor run on a host machine, which includes virtual machine function memory. The method also includes in response to detecting the request to access the resource, transferring, by the hypervisor, control of a virtual central processing unit (CPU) allocated to the guest to the virtual machine function. The method further includes receiving an indication that the virtual machine function has completed the access request on behalf of the guest. The virtual machine function may modify a state of the virtual CPU in virtual machine function memory. The method also includes synchronizing, by the hypervisor, a virtual machine function memory with the virtual CPU state.