Patch fix sched (#419)

1.解决waitqueue sleep的时候,由于preempt count不为0,导致sched失败,从而导致该waitqueue下一次wakeup时,会把pcb多次加入调度队列的bug
2.修复socket inode 的read和write方法里面没有使用no_preempt的问题
3. 修复cpu0的内核栈由于脏数据导致new_idle的时候set pcb报错的问题

---------

Co-authored-by: longjin <longjin@DragonOS.org>
This commit is contained in:
GnoCiYeH 2023-11-04 21:35:25 +08:00 committed by GitHub
parent 8058ccb307
commit 2f6f547ae0
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
12 changed files with 144 additions and 28 deletions

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@ -88,6 +88,7 @@ impl phy::TxToken for E1000ETxToken {
let result = f(buffer.as_mut_slice());
let mut device = self.driver.inner.lock();
device.e1000e_transmit(buffer);
buffer.free_buffer();
return result;
}
}

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@ -130,5 +130,4 @@ pub fn panic(info: &PanicInfo) -> ! {
println!("Current PCB:\n\t{:?}", *(ProcessManager::current_pcb()));
ProcessManager::exit(usize::MAX);
unreachable!();
}

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@ -44,6 +44,7 @@ pub struct RwLock<T> {
pub struct RwLockReadGuard<'a, T: 'a> {
data: *const T,
lock: &'a AtomicU32,
irq_guard: Option<IrqFlagsGuard>,
}
/// @brief UPGRADED是介于READER和WRITER之间的一种锁,它可以升级为WRITER,
@ -53,6 +54,7 @@ pub struct RwLockReadGuard<'a, T: 'a> {
pub struct RwLockUpgradableGuard<'a, T: 'a> {
data: *const T,
inner: &'a RwLock<T>,
irq_guard: Option<IrqFlagsGuard>,
}
/// @brief WRITER守卫的数据结构
@ -144,6 +146,7 @@ impl<T> RwLock<T> {
return Some(RwLockReadGuard {
data: unsafe { &*self.data.get() },
lock: &self.lock,
irq_guard: None,
});
}
}
@ -160,6 +163,19 @@ impl<T> RwLock<T> {
} //忙等待
}
pub fn read_irqsave(&self) -> RwLockReadGuard<T> {
loop {
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
match self.try_read() {
Some(mut guard) => {
guard.irq_guard = Some(irq_guard);
return guard;
}
None => spin_loop(),
}
}
}
#[allow(dead_code)]
#[inline]
/// @brief 获取读者+UPGRADER的数量, 不能保证能否获得同步值
@ -256,6 +272,7 @@ impl<T> RwLock<T> {
return Some(RwLockUpgradableGuard {
inner: self,
data: unsafe { &mut *self.data.get() },
irq_guard: None,
});
} else {
return None;
@ -274,6 +291,21 @@ impl<T> RwLock<T> {
}
}
#[inline]
/// @brief 获得UPGRADER守卫
pub fn upgradeable_read_irqsave(&self) -> RwLockUpgradableGuard<T> {
loop {
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
match self.try_upgradeable_read() {
Some(mut guard) => {
guard.irq_guard = Some(irq_guard);
return guard;
}
None => spin_loop(),
}
}
}
#[allow(dead_code)]
#[inline]
//extremely unsafe behavior
@ -332,7 +364,7 @@ impl<'rwlock, T> RwLockUpgradableGuard<'rwlock, T> {
#[allow(dead_code)]
#[inline]
/// @brief 尝试将UPGRADER守卫升级为WRITER守卫
pub fn try_upgrade(self) -> Result<RwLockWriteGuard<'rwlock, T>, Self> {
pub fn try_upgrade(mut self) -> Result<RwLockWriteGuard<'rwlock, T>, Self> {
let res = self.inner.lock.compare_exchange(
UPGRADED,
WRITER,
@ -343,13 +375,13 @@ impl<'rwlock, T> RwLockUpgradableGuard<'rwlock, T> {
if res.is_ok() {
let inner = self.inner;
let irq_guard = self.irq_guard.take();
mem::forget(self);
Ok(RwLockWriteGuard {
data: unsafe { &mut *inner.data.get() },
inner,
irq_guard: None,
irq_guard,
})
} else {
Err(self)
@ -373,19 +405,20 @@ impl<'rwlock, T> RwLockUpgradableGuard<'rwlock, T> {
#[allow(dead_code)]
#[inline]
/// @brief UPGRADER降级为READER
pub fn downgrade(self) -> RwLockReadGuard<'rwlock, T> {
pub fn downgrade(mut self) -> RwLockReadGuard<'rwlock, T> {
while self.inner.current_reader().is_err() {
spin_loop();
}
let inner: &RwLock<T> = self.inner;
let irq_guard = self.irq_guard.take();
// 自动移去UPGRADED比特位
mem::drop(self);
RwLockReadGuard {
data: unsafe { &*inner.data.get() },
lock: &inner.lock,
irq_guard,
}
}
@ -426,26 +459,27 @@ impl<'rwlock, T> RwLockWriteGuard<'rwlock, T> {
#[allow(dead_code)]
#[inline]
/// @brief 将WRITER降级为READER
pub fn downgrade(self) -> RwLockReadGuard<'rwlock, T> {
pub fn downgrade(mut self) -> RwLockReadGuard<'rwlock, T> {
while self.inner.current_reader().is_err() {
spin_loop();
}
//本质上来说绝对保证没有任何读者
let inner = self.inner;
let irq_guard = self.irq_guard.take();
mem::drop(self);
return RwLockReadGuard {
data: unsafe { &*inner.data.get() },
lock: &inner.lock,
irq_guard,
};
}
#[allow(dead_code)]
#[inline]
/// @brief 将WRITER降级为UPGRADER
pub fn downgrade_to_upgradeable(self) -> RwLockUpgradableGuard<'rwlock, T> {
pub fn downgrade_to_upgradeable(mut self) -> RwLockUpgradableGuard<'rwlock, T> {
debug_assert_eq!(
self.inner.lock.load(Ordering::Acquire) & (WRITER | UPGRADED),
WRITER
@ -455,11 +489,13 @@ impl<'rwlock, T> RwLockWriteGuard<'rwlock, T> {
let inner = self.inner;
let irq_guard = self.irq_guard.take();
mem::forget(self);
return RwLockUpgradableGuard {
inner,
data: unsafe { &*inner.data.get() },
irq_guard,
};
}
}

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@ -1,4 +1,6 @@
#![allow(dead_code)]
use core::intrinsics::unlikely;
use alloc::{collections::LinkedList, sync::Arc, vec::Vec};
use crate::{
@ -26,8 +28,20 @@ pub struct WaitQueue(SpinLock<InnerWaitQueue>);
impl WaitQueue {
pub const INIT: WaitQueue = WaitQueue(SpinLock::new(InnerWaitQueue::INIT));
fn before_sleep_check(&self, max_preempt: usize) {
let pcb = ProcessManager::current_pcb();
if unlikely(pcb.preempt_count() > max_preempt) {
kwarn!(
"Process {:?}: Try to sleep when preempt count is {}",
pcb.pid(),
pcb.preempt_count()
);
}
}
/// @brief 让当前进程在等待队列上进行等待,并且,允许被信号打断
pub fn sleep(&self) {
self.before_sleep_check(0);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock_irqsave();
ProcessManager::mark_sleep(true).unwrap_or_else(|e| {
panic!("sleep error: {:?}", e);
@ -42,6 +56,7 @@ impl WaitQueue {
where
F: FnOnce(),
{
self.before_sleep_check(0);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
ProcessManager::mark_sleep(true).unwrap_or_else(|e| {
@ -50,6 +65,7 @@ impl WaitQueue {
drop(irq_guard);
guard.wait_list.push_back(ProcessManager::current_pcb());
f();
drop(guard);
sched();
}
@ -69,6 +85,7 @@ impl WaitQueue {
/// 由于sleep_without_schedule不会调用调度函数因此如果开发者忘记在执行本函数之后手动调用调度函数
/// 由于时钟中断到来或者其他cpu kick了当前cpu可能会导致一些未定义的行为。
pub unsafe fn sleep_without_schedule(&self) {
self.before_sleep_check(0);
// 安全检查:确保当前处于中断禁止状态
assert!(CurrentIrqArch::is_irq_enabled() == false);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
@ -80,6 +97,7 @@ impl WaitQueue {
}
pub unsafe fn sleep_without_schedule_uninterruptible(&self) {
self.before_sleep_check(0);
// 安全检查:确保当前处于中断禁止状态
assert!(CurrentIrqArch::is_irq_enabled() == false);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
@ -91,6 +109,7 @@ impl WaitQueue {
}
/// @brief 让当前进程在等待队列上进行等待,并且,不允许被信号打断
pub fn sleep_uninterruptible(&self) {
self.before_sleep_check(0);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
ProcessManager::mark_sleep(false).unwrap_or_else(|e| {
@ -105,6 +124,7 @@ impl WaitQueue {
/// @brief 让当前进程在等待队列上进行等待,并且,允许被信号打断。
/// 在当前进程的pcb加入队列后解锁指定的自旋锁。
pub fn sleep_unlock_spinlock<T>(&self, to_unlock: SpinLockGuard<T>) {
self.before_sleep_check(1);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
ProcessManager::mark_sleep(true).unwrap_or_else(|e| {
@ -120,6 +140,7 @@ impl WaitQueue {
/// @brief 让当前进程在等待队列上进行等待,并且,允许被信号打断。
/// 在当前进程的pcb加入队列后解锁指定的Mutex。
pub fn sleep_unlock_mutex<T>(&self, to_unlock: MutexGuard<T>) {
self.before_sleep_check(1);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
ProcessManager::mark_sleep(true).unwrap_or_else(|e| {
@ -135,6 +156,7 @@ impl WaitQueue {
/// @brief 让当前进程在等待队列上进行等待,并且,不允许被信号打断。
/// 在当前进程的pcb加入队列后解锁指定的自旋锁。
pub fn sleep_uninterruptible_unlock_spinlock<T>(&self, to_unlock: SpinLockGuard<T>) {
self.before_sleep_check(1);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
ProcessManager::mark_sleep(false).unwrap_or_else(|e| {
@ -150,6 +172,7 @@ impl WaitQueue {
/// @brief 让当前进程在等待队列上进行等待,并且,不允许被信号打断。
/// 在当前进程的pcb加入队列后解锁指定的Mutex。
pub fn sleep_uninterruptible_unlock_mutex<T>(&self, to_unlock: MutexGuard<T>) {
self.before_sleep_check(1);
let mut guard: SpinLockGuard<InnerWaitQueue> = self.0.lock();
let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
ProcessManager::mark_sleep(false).unwrap_or_else(|e| {

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@ -1144,6 +1144,10 @@ impl SocketInode {
pub fn inner(&self) -> SpinLockGuard<Box<dyn Socket>> {
return self.0.lock();
}
pub unsafe fn inner_no_preempt(&self) -> SpinLockGuard<Box<dyn Socket>> {
return self.0.lock_no_preempt();
}
}
impl IndexNode for SocketInode {
@ -1173,7 +1177,7 @@ impl IndexNode for SocketInode {
buf: &mut [u8],
_data: &mut crate::filesystem::vfs::FilePrivateData,
) -> Result<usize, SystemError> {
return self.0.lock().read(&mut buf[0..len]).0;
return self.0.lock_no_preempt().read(&mut buf[0..len]).0;
}
fn write_at(
@ -1183,7 +1187,7 @@ impl IndexNode for SocketInode {
buf: &[u8],
_data: &mut crate::filesystem::vfs::FilePrivateData,
) -> Result<usize, SystemError> {
return self.0.lock().write(&buf[0..len], None);
return self.0.lock_no_preempt().write(&buf[0..len], None);
}
fn poll(&self) -> Result<crate::filesystem::vfs::PollStatus, SystemError> {

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@ -173,7 +173,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let mut socket = socket.inner();
let mut socket = unsafe { socket.inner_no_preempt() };
// kdebug!("connect to {:?}...", endpoint);
socket.connect(endpoint)?;
return Ok(0);
@ -191,7 +191,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let mut socket = socket.inner();
let mut socket = unsafe { socket.inner_no_preempt() };
socket.bind(endpoint)?;
return Ok(0);
}
@ -221,7 +221,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let socket = socket.inner();
let socket = unsafe { socket.inner_no_preempt() };
return socket.write(buf, endpoint);
}
@ -244,7 +244,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let socket = socket.inner();
let socket = unsafe { socket.inner_no_preempt() };
let (n, endpoint) = socket.read(buf);
drop(socket);
@ -275,7 +275,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let socket = socket.inner();
let socket = unsafe { socket.inner_no_preempt() };
let mut buf = iovs.new_buf(true);
// 从socket中读取数据
@ -304,7 +304,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let mut socket = socket.inner();
let mut socket = unsafe { socket.inner_no_preempt() };
socket.listen(backlog)?;
return Ok(0);
}
@ -319,7 +319,7 @@ impl Syscall {
let socket: Arc<SocketInode> = ProcessManager::current_pcb()
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
let socket = socket.inner();
let socket = unsafe { socket.inner_no_preempt() };
socket.shutdown(ShutdownType::try_from(how as i32)?)?;
return Ok(0);
}
@ -336,7 +336,7 @@ impl Syscall {
.get_socket(fd as i32)
.ok_or(SystemError::EBADF)?;
// kdebug!("accept: socket={:?}", socket);
let mut socket = socket.inner();
let mut socket = unsafe { socket.inner_no_preempt() };
// 从socket中接收连接
let (new_socket, remote_endpoint) = socket.accept()?;
drop(socket);

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@ -37,8 +37,10 @@ impl ProcessManager {
let stack_ptr =
VirtAddr::new(Self::stack_ptr().data() & (!(KernelStack::ALIGN - 1)));
// 初始化bsp的idle进程
unsafe { KernelStack::from_existed(stack_ptr) }
.expect("Failed to create kernel stack struct for BSP.")
let mut ks = unsafe { KernelStack::from_existed(stack_ptr) }
.expect("Failed to create kernel stack struct for BSP.");
unsafe { ks.clear_pcb(true) };
ks
} else {
KernelStack::new().unwrap_or_else(|e| {
panic!("Failed to create kernel stack struct for AP {}: {:?}", i, e)

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@ -34,7 +34,7 @@ use crate::{
constant::{FutexFlag, FUTEX_BITSET_MATCH_ANY},
futex::Futex,
},
rwlock::{RwLock, RwLockReadGuard, RwLockWriteGuard},
rwlock::{RwLock, RwLockReadGuard, RwLockUpgradableGuard, RwLockWriteGuard},
spinlock::{SpinLock, SpinLockGuard},
wait_queue::WaitQueue,
},
@ -235,6 +235,7 @@ impl ProcessManager {
///
/// - 进入当前函数之前不能持有sched_info的锁
/// - 进入当前函数之前,必须关闭中断
/// - 进入当前函数之后必须保证逻辑的正确性,避免被重复加入调度队列
pub fn mark_sleep(interruptable: bool) -> Result<(), SystemError> {
assert_eq!(
CurrentIrqArch::is_irq_enabled(),
@ -692,6 +693,17 @@ impl ProcessControlBlock {
return self.sched_info.read();
}
#[allow(dead_code)]
#[inline(always)]
pub fn sched_info_irqsave(&self) -> RwLockReadGuard<ProcessSchedulerInfo> {
return self.sched_info.read_irqsave();
}
#[inline(always)]
pub fn sched_info_upgradeable_irqsave(&self) -> RwLockUpgradableGuard<ProcessSchedulerInfo> {
return self.sched_info.upgradeable_read();
}
#[inline(always)]
pub fn sched_info_mut(&self) -> RwLockWriteGuard<ProcessSchedulerInfo> {
return self.sched_info.write();
@ -977,7 +989,7 @@ impl ProcessSchedulerInfo {
return self.state;
}
fn set_state(&mut self, state: ProcessState) {
pub fn set_state(&mut self, state: ProcessState) {
self.state = state;
}
@ -1069,6 +1081,7 @@ impl KernelStack {
// 如果内核栈的最低地址处已经有了一个pcb那么这里就不再设置,直接返回错误
if unlikely(unsafe { !(*stack_bottom_ptr).is_null() }) {
kerror!("kernel stack bottom is not null: {:p}", *stack_bottom_ptr);
return Err(SystemError::EPERM);
}
// 将pcb的地址放到内核栈的最低地址处
@ -1079,6 +1092,25 @@ impl KernelStack {
return Ok(());
}
/// 清除内核栈的pcb指针
///
/// ## 参数
///
/// - `force` : 如果为true,那么即使该内核栈的pcb指针不为null也会被强制清除而不处理Weak指针问题
pub unsafe fn clear_pcb(&mut self, force: bool) {
let stack_bottom_ptr = self.start_address().data() as *mut *const ProcessControlBlock;
if unlikely(unsafe { (*stack_bottom_ptr).is_null() }) {
return;
}
if !force {
let pcb_ptr: Weak<ProcessControlBlock> = Weak::from_raw(*stack_bottom_ptr);
drop(pcb_ptr);
}
*stack_bottom_ptr = core::ptr::null();
}
/// 返回指向当前内核栈pcb的Arc指针
#[allow(dead_code)]
pub unsafe fn pcb(&self) -> Option<Arc<ProcessControlBlock>> {

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@ -98,6 +98,24 @@ pub trait Scheduler {
pub fn do_sched() -> Option<Arc<ProcessControlBlock>> {
// 当前进程持有锁,不切换,避免死锁
if ProcessManager::current_pcb().preempt_count() != 0 {
let binding = ProcessManager::current_pcb();
let mut guard = binding.sched_info_upgradeable_irqsave();
let state = guard.state();
if state.is_blocked() {
// try to upgrade
for _ in 0..50 {
match guard.try_upgrade() {
Ok(mut writer) => {
// 被mark_sleep但是还在临界区的进程将其设置为Runnable
writer.set_state(ProcessState::Runnable);
break;
}
Err(s) => {
guard = s;
}
}
}
}
return None;
}
compiler_fence(core::sync::atomic::Ordering::SeqCst);

3
tools/.gitignore vendored
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@ -5,4 +5,5 @@ arch/i386/efi/grub/*
arch/x86_64/efi/grub/*
*.tar.gz
build/*
build/*
target/

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@ -48,8 +48,8 @@ EOF
echo "Creating virtual disk image..."
ARGS=`getopt -o P: -- "$@"`
# 创建一至少为64MB磁盘镜像类型选择raw
qemu-img create -f raw disk.img 64M
# 创建一至少为256MB磁盘镜像类型选择raw
qemu-img create -f raw disk.img 256M
#将规范化后的命令行参数分配至位置参数($1,$2,...)
eval set -- "${ARGS}"
#echo formatted parameters=[$@]

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@ -62,9 +62,9 @@ QEMU_DRIVE="id=disk,file=${QEMU_DISK_IMAGE},if=none"
# ps: 下面这条使用tap的方式无法dhcp获取到ip暂时不知道为什么
# QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -net nic,netdev=nic0 -netdev tap,id=nic0,model=virtio-net-pci,script=qemu/ifup-nat,downscript=qemu/ifdown-nat -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel} -machine q35 "
# QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -netdev user,id=hostnet0,hostfwd=tcp::12580-:12580 -device virtio-net-pci,vectors=5,netdev=hostnet0,id=net0 -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel} -machine q35 "
QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -netdev user,id=hostnet0,hostfwd=tcp::12580-:12580 -device virtio-net-pci,vectors=5,netdev=hostnet0,id=net0 -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel} -machine q35 "
# E1000E
QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -netdev user,id=hostnet0,hostfwd=tcp::12580-:12580 -net nic,model=e1000e,netdev=hostnet0,id=net0 -netdev user,id=hostnet1,hostfwd=tcp::12581-:12581 -device virtio-net-pci,vectors=5,netdev=hostnet1,id=net1 -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel} -machine q35 "
#QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -netdev user,id=hostnet0,hostfwd=tcp::12580-:12580 -net nic,model=e1000e,netdev=hostnet0,id=net0 -netdev user,id=hostnet1,hostfwd=tcp::12581-:12581 -device virtio-net-pci,vectors=5,netdev=hostnet1,id=net1 -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel} -machine q35 "
QEMU_ARGUMENT="-d ${QEMU_DISK_IMAGE} -m ${QEMU_MEMORY} -smp ${QEMU_SMP} -boot order=d -monitor ${QEMU_MONITOR} -d ${qemu_trace_std} "
QEMU_ARGUMENT+="-s -S -enable-kvm -cpu ${QEMU_CPU_FEATURES} -rtc ${QEMU_RTC_CLOCK} -serial ${QEMU_SERIAL} -drive ${QEMU_DRIVE} ${QEMU_DEVICES}"