fix: boot application processors after initializing scheduler

.github/workflows/ci.yml

@@ -250,5 +250,7 @@ jobs:
         if: matrix.arch == 'x86_64'
       - run: UHYVE=$CARGO_HOME/bin/uhyve cargo xtask ci uhyve --arch ${{ matrix.arch }} --profile ${{ matrix.profile }} --sudo --package rusty_demo
         if: matrix.arch == 'x86_64'
+      - run: UHYVE=$CARGO_HOME/bin/uhyve cargo xtask ci uhyve --arch ${{ matrix.arch }} --profile ${{ matrix.profile }} --sudo --package rusty_demo --smp
+        if: matrix.arch == 'x86_64'
       - run: FIRECRACKER=$HOME/.local/bin/firecracker cargo xtask ci firecracker --arch ${{ matrix.arch }} --profile ${{ matrix.profile }} --sudo --package hello_world --no-default-features
         if: matrix.arch == 'x86_64'

src/arch/aarch64/kernel/mod.rs

@@ -156,12 +156,6 @@ pub fn boot_processor_init() {
 	finish_processor_init();
 }
 
-/// Boots all available Application Processors on bare-metal or QEMU.
-/// Called after the Boot Processor has been fully initialized along with its scheduler.
-pub fn boot_application_processors() {
-	// Nothing to do here yet.
-}
-
 /// Application Processor initialization
 #[allow(dead_code)]
 pub fn application_processor_init() {
@@ -171,7 +165,9 @@ pub fn application_processor_init() {
 
 fn finish_processor_init() {
 	debug!("Initialized Processor");
+}
 
+pub fn boot_next_processor() {
 	CPU_ONLINE.fetch_add(1, Ordering::Release);
 }
 

src/arch/mod.rs

@@ -19,7 +19,6 @@ cfg_if::cfg_if! {
 		#[cfg(feature = "smp")]
 		pub(crate) use self::aarch64::kernel::application_processor_init;
 		pub(crate) use self::aarch64::kernel::{
-			boot_application_processors,
 			get_processor_count,
 			message_output_init,
 			output_message_buf,
@@ -44,10 +43,7 @@ cfg_if::cfg_if! {
 		pub(crate) use self::x86_64::kernel::scheduler;
 		pub(crate) use self::x86_64::kernel::switch;
 		#[cfg(target_os = "none")]
-		pub(crate) use self::x86_64::kernel::{
-			boot_application_processors,
-			boot_processor_init,
-		};
+		pub(crate) use self::x86_64::kernel::boot_processor_init;
 		pub(crate) use self::x86_64::kernel::{
 			get_processor_count,
 			message_output_init,
@@ -68,7 +64,6 @@ cfg_if::cfg_if! {
 		pub(crate) use self::riscv64::kernel::pci;
 		pub(crate) use self::riscv64::kernel::processor::{self, set_oneshot_timer, wakeup_core};
 		pub(crate) use self::riscv64::kernel::{
-			boot_application_processors,
 			boot_processor_init,
 			core_local,
 			get_processor_count,

src/arch/riscv64/kernel/mod.rs

@@ -141,12 +141,6 @@ pub fn boot_processor_init() {
 	interrupts::enable();
 }
 
-/// Boots all available Application Processors on bare-metal or QEMU.
-/// Called after the Boot Processor has been fully initialized along with its scheduler.
-pub fn boot_application_processors() {
-	// Nothing to do here yet.
-}
-
 /// Application Processor initialization
 #[cfg(feature = "smp")]
 pub fn application_processor_init() {
@@ -179,6 +173,10 @@ fn finish_processor_init() {
 	// Remove current hart from the hart_mask
 	let new_hart_mask = get_hart_mask() & (u64::MAX - (1 << current_hart_id));
 	HART_MASK.store(new_hart_mask, Ordering::Relaxed);
+}
+
+pub fn boot_next_processor() {
+	let new_hart_mask = HART_MASK.load(Ordering::Relaxed);
 
 	let next_hart_index = lsb(new_hart_mask);
 

src/arch/x86_64/kernel/apic.rs

@@ -804,6 +804,8 @@ pub fn boot_application_processors() {
 			}
 		}
 	}
+
+	print_information();
 }
 
 #[cfg(feature = "smp")]

src/arch/x86_64/kernel/mod.rs

@@ -194,15 +194,6 @@ pub fn boot_processor_init() {
 	interrupts::enable();
 }
 
-/// Boots all available Application Processors on bare-metal or QEMU.
-/// Called after the Boot Processor has been fully initialized along with its scheduler.
-#[cfg(target_os = "none")]
-pub fn boot_application_processors() {
-	#[cfg(feature = "smp")]
-	apic::boot_application_processors();
-	apic::print_information();
-}
-
 /// Application Processor initialization
 #[cfg(all(target_os = "none", feature = "smp"))]
 pub fn application_processor_init() {
@@ -231,10 +222,23 @@ fn finish_processor_init() {
 		// Therefore, the current processor already needs to prepare the processor variables for a possible next processor.
 		apic::init_next_processor_variables();
 	}
+}
 
+pub fn boot_next_processor() {
 	// This triggers apic::boot_application_processors (bare-metal/QEMU) or uhyve
 	// to initialize the next processor.
-	CPU_ONLINE.fetch_add(1, Ordering::Release);
+	let cpu_online = CPU_ONLINE.fetch_add(1, Ordering::Release);
+
+	if !env::is_uhyve() {
+		if cpu_online == 0 {
+			#[cfg(all(target_os = "none", feature = "smp"))]
+			apic::boot_application_processors();
+		}
+
+		if !cfg!(feature = "smp") {
+			apic::print_information();
+		}
+	}
 }
 
 pub fn print_statistics() {

src/lib.rs

@@ -211,9 +211,7 @@ fn boot_processor_main() -> ! {
 	#[cfg(not(target_arch = "riscv64"))]
 	scheduler::add_current_core();
 
-	if !env::is_uhyve() {
-		arch::boot_application_processors();
-	}
+	arch::kernel::boot_next_processor();
 
 	#[cfg(feature = "smp")]
 	synch_all_cores();
@@ -253,6 +251,7 @@ fn application_processor_main() -> ! {
 	arch::application_processor_init();
 	#[cfg(not(target_arch = "riscv64"))]
 	scheduler::add_current_core();
+	arch::kernel::boot_next_processor();
 
 	debug!("Entering idle loop for application processor");