Method register_percpu_buf

devices/src/pvmemcontrol.rs:286–326

(
        guest_memory: &GuestMemoryAtomic<GuestMemoryMmap<AtomicBitmap>>,
        mut state: PercpuInitState,
        PvmemcontrolTransportRegister { buf_phys_addr }: PvmemcontrolTransportRegister,
 

impl PvmemcontrolDevice {
    fn register_percpu_buf(
        guest_memory: &GuestMemoryAtomic<GuestMemoryMmap<AtomicBitmap>>,
        mut state: PercpuInitState,
        PvmemcontrolTransportRegister { buf_phys_addr }: PvmemcontrolTransportRegister,
    ) -> Self {
        // access to this address is checked
        let buf_phys_addr = GuestAddress(buf_phys_addr.into());
        if !guest_memory.memory().check_range(
            buf_phys_addr,
            std::mem::size_of::<PvmemcontrolResp>().max(std::mem::size_of::<PvmemcontrolReq>()),
        ) {
            warn!("guest sent invalid phys addr {:#x}", buf_phys_addr.0);
            return PvmemcontrolDevice::new(
                PvmemcontrolTransport::error(),
                PvmemcontrolState::Broken,
            );
        }

        let conn = {
            // find an available port+byte combination, and fail if full
            let mut next_conn = state.next_conn;
            while state.port_buf_map.contains_key(&next_conn) {
                next_conn = next_conn.next();
                if next_conn == state.next_conn {
                    warn!("connections exhausted");
                    return PvmemcontrolDevice::new(
                        PvmemcontrolTransport::error(),
                        PvmemcontrolState::Broken,
                    );
                }
            }
            next_conn
        };
        state.next_conn = conn.next();
        state.port_buf_map.insert(conn, buf_phys_addr);

        // inform guest of the connection
        let response = PvmemcontrolTransport::register_response(conn.command);

        PvmemcontrolDevice::new(response, PvmemcontrolState::PercpuInit(state))
    }

    fn reset() -> Self {
        PvmemcontrolDevice::new(