Function start_vmm

cloud-hypervisor/src/main.rs:505–780

(
    cmd_arguments: &ArgMatches,
    api_socket_path: &Option<String>,
    api_socket_fd: Option<RawFd>,
)

}

fn start_vmm(
    cmd_arguments: &ArgMatches,
    api_socket_path: &Option<String>,
    api_socket_fd: Option<RawFd>,
) -> Result<(), Error> {
    let log_level = match cmd_arguments.get_count("v") {
        0 => LevelFilter::Warn,
        1 => LevelFilter::Info,
        2 => LevelFilter::Debug,
        _ => LevelFilter::Trace,
    };

    let log_file: Box<dyn std::io::Write + Send> = if let Some(ref file) =
        cmd_arguments.get_one::<String>("log-file")
    {
        Box::new(std::fs::File::create(std::path::Path::new(file)).map_err(Error::LogFileCreation)?)
    } else {
        Box::new(std::io::stderr())
    };

    let format = cmd_arguments.get_one::<String>("log-format").unwrap();
    let logger = Logger::new(log_file, format).map_err(Error::LoggerFormat)?;
    log::set_boxed_logger(Box::new(logger))
        .map(|()| log::set_max_level(log_level))
        .map_err(Error::LoggerSetup)?;

    let (api_request_sender, api_request_receiver) = channel();
    let api_evt = EventFd::new(EFD_NONBLOCK).map_err(Error::CreateApiEventFd)?;

    let api_request_sender_clone = api_request_sender.clone();
    let seccomp_action = if let Some(seccomp_value) = cmd_arguments.get_one::<String>("seccomp") {
        match seccomp_value as &str {
            "true" => SeccompAction::Trap,
            "false" => SeccompAction::Allow,
            "log" => SeccompAction::Log,
            val => {
                // The user providing an invalid value will be rejected
                panic!("Invalid parameter {val} for \"--seccomp\" flag");
            }
        }
    } else {
        SeccompAction::Trap
    };

    if seccomp_action == SeccompAction::Trap {
        // SAFETY: We only using signal_hook for managing signals and only execute signal
        // handler safe functions (writing to stderr) and manipulating signals.
        unsafe {
            signal_hook::low_level::register(signal_hook::consts::SIGSYS, || {
                eprintln!(
                    "\n==== Possible seccomp violation ====\n\
                Try running with `strace -ff` to identify the cause and open an issue: \
                https://github.com/cloud-hypervisor/cloud-hypervisor/issues/new"
                );
                signal_hook::low_level::emulate_default_handler(SIGSYS).unwrap();
            })
        }
        .map_err(|e| error!("Error adding SIGSYS signal handler: {e}"))