HVMM in PseudoCode

                
Control Flow
 
BIOS -> BOOTLOADER -> HVMM

HVMM Pseudo-Code
{
        INITIALIZE_SVM();
        HYPERVISOR();
}

LOAD_VMM_UI() {
        //display text based interface listing guest OS choices
        //wait for user input
}

INITIALIZE_SVM() {
        ENABLE_SVM();
        SETUP_HYPERVISOR();
}

ENABLE_SVM() {
        EFER.SVME = 1;
}

SETUP_HYPERVISOR() {
        ALLOCATE_HYPERVISOR_CODE();
        LOAD_HYPERVISOR_CODE();
        ALLOCATE_HOST_STATE_AREA();
}

ALLOCATE_HYPERVISOR_CODE() {
        //allocate a non-paged area in kernel memory
}

LOAD_HYPERVISOR_CODE() {
        //copy the hypervisor code to memory
}

ALLOCATE_HOST_STATE_AREA() {
        //allocate a non-paged contiguous physical memory space for a host save area
        //store the physical address to this area in the VM_HSAVE_PA register
}

HYPERVISOR() {
      while (1) {
              If(vmm_switch) {
                      LAUNCH_VMM_UI();
                      vmcb = GET_SELECTED_VMCB();
                      if(vmcb = NULL) {
                              vmcb = SETUP_VMCB();
                              ADD_ACTIVE(vmcb);
                      }
                      LAUNCH_VM_UI();
              }
              else {
                      vmcb = GET_NEXT_VMCB(); // from scheduler
              }
              rax = &VMCB;
              VMLOAD(rax);
              While(running_vm) {
                      VMRUN(rax);
                      Switch(exit_code) {
                                //handle interrupt in each case
                              If(timer_expire OR vmm_switch or power_off) break;
                      }
              }
              If(power_off) REMOVE_ACTIVE(rax);
              Else VMSAVE(rax);
      }
}

SETUP_VMCB() {
      ALLOCATE_VMCB();
        // CLGI instruction is executed to disable global interrupts
      // initialize the control area of the with a set of intercept conditions that will cause execution to transfer out of the guest and
back to the hypervisor
        // initialize the guest area of the VMCB with the address where guest execution should begin
}

ALLOCATE_VMCB() {
        //allocate a region of physically contiguous, page-aligned, non-pageable memory
}