use rvm::*;
const ENTRY: u64 = 0x2000;
fn run_hypervisor() -> RvmResult {
    // create a guest physical memory set.
    let gpm = DefaultGuestPhysMemorySet::new();
    // create a guest.
    let guest = Guest::new(gpm)?;
    // create a vcpu.
    let mut vcpu = Vcpu::new(ENTRY, guest.clone())?;
    // map the guest physical memory region [0, 0x8000) to the host phyical
    // memory region [0xC0000, 0xC8000).
    let host_paddr = 0xC0000;
    guest.add_memory_region(0, 0x8000, Some(0xC0000))?;
    // I/O instructions with port 0x233-0x234 can cause VM exit and `vcpu.resume()`
    // to return.
    guest.set_trap(TrapKind::GuestTrapIo, 0x233, 2, None, 0xdeadbeef)?;
    // The bootstrap processor is in IA-32e mode and enabled paging, you need to
    // setup guest page table.
    setup_guest_page_table(host_paddr);
    // run the VCPU and block, until the specified traps occurs.
    let packet = vcpu.resume()?;
    // get the VCPU state.
    let state = vcpu.read_state()?;
    Ok(())
}