feat(shutdown): always try qemu debug exit for error codes

Cargo.toml

@@ -128,7 +128,6 @@ multiboot = "0.8"
 uart_16550 = "0.3"
 x86 = { version = "0.52", default-features = false }
 x86_64 = "0.15"
-qemu-exit = "3.0"
 
 [target.'cfg(target_arch = "aarch64")'.dependencies]
 aarch64 = { version = "0.0", default-features = false }

src/arch/x86_64/kernel/acpi.rs

@@ -1,12 +1,10 @@
-use core::convert::Infallible;
 use core::{mem, ptr, slice, str};
 
 use align_address::Align;
 use hermit_sync::OnceCell;
 use x86::io::*;
 use x86_64::structures::paging::PhysFrame;
 
-use crate::arch::x86_64::kernel::processor;
 use crate::arch::x86_64::mm::paging::{
 	BasePageSize, PageSize, PageTableEntryFlags, PageTableEntryFlagsExt,
 };
@@ -446,7 +444,7 @@ pub fn get_madt() -> Option<&'static AcpiTable<'static>> {
 	MADT.get()
 }
 
-pub fn poweroff() -> Result<Infallible, ()> {
+pub fn poweroff() {
 	if let (Some(&pm1a_cnt_blk), Some(&slp_typa)) = (PM1A_CNT_BLK.get(), SLP_TYPA.get()) {
 		let bits = (u16::from(slp_typa) << 10) | SLP_EN;
 		debug!(
@@ -456,12 +454,8 @@ pub fn poweroff() -> Result<Infallible, ()> {
 		unsafe {
 			outw(pm1a_cnt_blk, bits);
 		}
-		loop {
-			processor::halt();
-		}
 	} else {
 		warn!("ACPI Power Off is not available");
-		Err(())
 	}
 }
 

src/arch/x86_64/kernel/processor.rs

@@ -4,20 +4,19 @@ use core::arch::asm;
 use core::arch::x86_64::{
 	__rdtscp, _fxrstor, _fxsave, _mm_lfence, _rdseed64_step, _rdtsc, _xrstor, _xsave,
 };
-use core::convert::Infallible;
 use core::hint::spin_loop;
 use core::num::NonZeroU32;
 use core::sync::atomic::{AtomicU64, Ordering};
 use core::{fmt, ptr, u32};
 
 use hermit_entry::boot_info::PlatformInfo;
 use hermit_sync::Lazy;
-use qemu_exit::QEMUExit;
 use x86::bits64::segmentation;
 use x86::controlregs::*;
 use x86::cpuid::*;
 use x86::msr::*;
 use x86_64::instructions::interrupts::int3;
+use x86_64::instructions::port::Port;
 use x86_64::instructions::tables::lidt;
 use x86_64::structures::DescriptorTablePointer;
 use x86_64::VirtAddr;
@@ -1028,38 +1027,30 @@ fn triple_fault() -> ! {
 	unreachable!()
 }
 
+fn qemu_exit(success: bool) {
+	let code = if success { 3 >> 1 } else { 0 };
+	unsafe {
+		Port::<u32>::new(0xf4).write(code);
+	}
+}
+
 /// Shutdown the system
 pub fn shutdown(error_code: i32) -> ! {
-	info!("Shutting down system");
-	let acpi_result: Result<Infallible, ()> = {
-		#[cfg(feature = "acpi")]
-		{
-			acpi::poweroff()
-		}
-
-		#[cfg(not(feature = "acpi"))]
-		{
-			Err(())
-		}
-	};
+	match boot_info().platform_info {
+		PlatformInfo::LinuxBootParams { .. } => triple_fault(),
+		PlatformInfo::Multiboot { .. } => {
+			qemu_exit(error_code == 0);
+
+			#[cfg(feature = "acpi")]
+			{
+				acpi::poweroff();
+			}
 
-	match acpi_result {
-		Ok(_never) => unreachable!(),
-		Err(()) => {
-			match boot_info().platform_info {
-				PlatformInfo::LinuxBootParams { .. } => triple_fault(),
-				PlatformInfo::Multiboot { .. } => {
-					// Try QEMU's debug exit
-					let exit_handler = qemu_exit::X86::new(0xf4, 3);
-					if error_code == 0 {
-						exit_handler.exit_success()
-					} else {
-						exit_handler.exit_failure()
-					}
-				}
-				PlatformInfo::Uhyve { .. } => todo!(),
+			loop {
+				halt();
 			}
 		}
+		PlatformInfo::Uhyve { .. } => unreachable!(),
 	}
 }
 

src/syscalls/mod.rs

@@ -200,6 +200,7 @@ pub(crate) fn get_application_parameters() -> (i32, *const *const u8, *const *co
 pub(crate) fn shutdown(arg: i32) -> ! {
 	// print some performance statistics
 	crate::arch::kernel::print_statistics();
+	info!("shutting down with code {arg}");
 
 	SYS.shutdown(arg)
 }

xtask/src/ci/qemu.rs

@@ -91,7 +91,11 @@ impl Qemu {
 
 		thread::sleep(Duration::from_millis(100));
 		if let Some(status) = qemu.0.try_wait()? {
-			ensure!(status.qemu_success(), "QEMU exit code: {:?}", status.code());
+			ensure!(
+				self.qemu_success(status),
+				"QEMU exit code: {:?}",
+				status.code()
+			);
 		}
 
 		match self.build.package.as_str() {
@@ -107,7 +111,11 @@ impl Qemu {
 		let Some(status) = status else {
 			bail!("QEMU timeout")
 		};
-		ensure!(status.qemu_success(), "QEMU exit code: {:?}", status.code());
+		ensure!(
+			self.qemu_success(status),
+			"QEMU exit code: {:?}",
+			status.code()
+		);
 
 		if let Some(mut virtiofsd) = virtiofsd {
 			let status = virtiofsd.0.wait()?;
@@ -250,6 +258,14 @@ impl Qemu {
 			vec![]
 		}
 	}
+
+	fn qemu_success(&self, status: ExitStatus) -> bool {
+		if self.build.cargo_build.artifact.arch == Arch::X86_64 {
+			status.code() == Some(3)
+		} else {
+			status.success()
+		}
+	}
 }
 
 fn spawn_virtiofsd() -> Result<KillChildOnDrop> {
@@ -374,13 +390,3 @@ impl Drop for KillChildOnDrop {
 		self.0.kill().ok();
 	}
 }
-
-trait ExitStatusExt {
-	fn qemu_success(&self) -> bool;
-}
-
-impl ExitStatusExt for ExitStatus {
-	fn qemu_success(&self) -> bool {
-		self.success() || self.code() == Some(3)
-	}
-}