Log messages to the serial atomically and rename arch::serial

Co-authored-by: Chuandong Li <lichuand@pku.edu.cn>

kernel/aster-nix/src/console.rs

@@ -18,6 +18,7 @@ impl Write for VirtioConsolesPrinter {
     }
 }
 
+/// Prints the formatted arguments to the standard output.
 pub fn _print(args: Arguments) {
     VirtioConsolesPrinter.write_fmt(args).unwrap();
 }

kernel/aster-nix/src/device/tty/driver.rs

@@ -2,7 +2,6 @@
 
 #![allow(dead_code)]
 
-pub use ostd::arch::console;
 use ostd::mm::VmReader;
 use spin::Once;
 

ostd/src/arch/x86/mod.rs

@@ -3,7 +3,6 @@
 //! Platform-specific code for the x86 platform.
 
 pub mod boot;
-pub mod console;
 pub(crate) mod cpu;
 pub mod device;
 pub(crate) mod ex_table;
@@ -13,6 +12,7 @@ pub(crate) mod kernel;
 pub(crate) mod mm;
 pub(crate) mod pci;
 pub mod qemu;
+pub mod serial;
 pub mod task;
 #[cfg(feature = "intel_tdx")]
 pub(crate) mod tdx_guest;
@@ -31,7 +31,7 @@ use log::{info, warn};
 
 pub(crate) fn before_all_init() {
     enable_common_cpu_features();
-    console::init();
+    serial::init();
 }
 
 pub(crate) fn after_all_init() {
@@ -46,7 +46,7 @@ pub(crate) fn after_all_init() {
             kernel::pic::enable();
         }
     }
-    console::callback_init();
+    serial::callback_init();
     timer::init();
     #[cfg(feature = "intel_tdx")]
     if !tdx_is_enabled() {

ostd/src/arch/x86/serial.rs

@@ -15,7 +15,7 @@ use trapframe::TrapFrame;
 use super::{device::serial::SerialPort, kernel::IO_APIC};
 use crate::{sync::SpinLock, trap::IrqLine};
 
-/// Prints the formatted arguments to the standard output.
+/// Prints the formatted arguments to the standard output using the serial port.
 #[inline]
 pub fn print(args: fmt::Arguments) {
     Stdout.write_fmt(args).unwrap();

ostd/src/boot/mod.rs

@@ -158,7 +158,7 @@ fn run_ktests(test_whitelist: Option<&[&str]>, crate_whitelist: Option<&[&str]>)
 
     use ktest::runner::{run_ktests, KtestResult};
     match run_ktests(
-        &crate::console::print,
+        &crate::console::early_print,
         fn_catch_unwind,
         test_whitelist.map(|s| s.iter().map(|s| s.to_string())),
         crate_whitelist,

ostd/src/console.rs

@@ -5,23 +5,23 @@
 use core::fmt::Arguments;
 
 /// Prints formatted arguments to the console.
-pub fn print(args: Arguments) {
-    crate::arch::console::print(args);
+pub fn early_print(args: Arguments) {
+    crate::arch::serial::print(args);
 }
 
 /// Prints to the console.
 #[macro_export]
 macro_rules! early_print {
-  ($fmt: literal $(, $($arg: tt)+)?) => {
-    $crate::console::print(format_args!($fmt $(, $($arg)+)?))
-  }
+    ($fmt: literal $(, $($arg: tt)+)?) => {
+        $crate::console::early_print(format_args!($fmt $(, $($arg)+)?))
+    }
 }
 
-/// Prints to the console, with a newline.
+/// Prints to the console with a newline.
 #[macro_export]
 macro_rules! early_println {
-  () => { $crate::early_print!("\n") };
-  ($fmt: literal $(, $($arg: tt)+)?) => {
-    $crate::console::print(format_args!(concat!($fmt, "\n") $(, $($arg)+)?))
-  }
+    () => { $crate::early_print!("\n") };
+    ($fmt: literal $(, $($arg: tt)+)?) => {
+        $crate::console::early_print(format_args!(concat!($fmt, "\n") $(, $($arg)+)?))
+    }
 }

ostd/src/logger.rs

@@ -1,6 +1,14 @@
 // SPDX-License-Identifier: MPL-2.0
 
 //! Logging support.
+//!
+//! Currently the logger prints the logs to the console.
+//!
+//! This module guarantees _atomicity_ under concurrency: messages are always
+//! printed in their entirety without being mixed with messages generated
+//! concurrently on other cores.
+//!
+//! IRQs are disabled while printing. So do not print long log messages.
 
 use alloc::format;
 
@@ -48,6 +56,11 @@ impl log::Log for Logger {
             (timestamp, level, record_str)
         };
 
+        // Use a global lock to prevent interleaving of log messages.
+        use crate::sync::SpinLock;
+        static RECORD_LOCK: SpinLock<()> = SpinLock::new(());
+        let _lock = RECORD_LOCK.lock_irq_disabled();
+
         early_println!("{} {}: {}", timestamp, level, record_str);
     }