virtualizationmanager/src/debug_config.rs

// Copyright 2023, The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Functions for AVF debug policy and debug level

use android_system_virtualizationservice::aidl::android::system::virtualizationservice::{
    VirtualMachineAppConfig::DebugLevel::DebugLevel
};
use std::fs::File;
use std::io::Read;

/// Get debug policy value in bool. It's true iff the value is explicitly set to <1>.
fn get_debug_policy_bool(path: &'static str) -> Option<bool> {
    if let Ok(mut file) = File::open(path) {
        let mut log: [u8; 4] = Default::default();
        file.read_exact(&mut log).map_err(|_| false).unwrap();
        // DT spec uses big endian although Android is always little endian.
        return Some(u32::from_be_bytes(log) == 1);
    }
    None
}

/// Get whether console output should be configred for VM to leave console and adb log.
/// Caller should create pipe and prepare for receiving VM log with it.
pub fn should_prepare_console_output(debug_level: DebugLevel) -> bool {
    debug_level != DebugLevel::NONE
        || get_debug_policy_bool("/proc/device-tree/avf/guest/common/log").unwrap_or_default()
}