rust: hpet: embed Timer without the Option and Box indirection

This simplifies things for migration, since Option<Box<QEMUTimer>> does not
implement VMState.

This also shows a soundness issue because Timer::new() will leave a NULL
timer list pointer, which can then be dereferenced by Timer::modify().  It
will be fixed shortly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2025-03-03 16:27:08 +01:00
parent d7f5ae8b30
commit e8dc87fef2

View file

@ -151,14 +151,14 @@ fn timer_handler(timer_cell: &BqlRefCell<HPETTimer>) {
/// HPET Timer Abstraction
#[repr(C)]
#[derive(Debug, Default, qemu_api_macros::offsets)]
#[derive(Debug, qemu_api_macros::offsets)]
pub struct HPETTimer {
/// timer N index within the timer block (`HPETState`)
#[doc(alias = "tn")]
index: usize,
qemu_timer: Option<Box<Timer>>,
qemu_timer: Timer,
/// timer block abstraction containing this timer
state: Option<NonNull<HPETState>>,
state: NonNull<HPETState>,
// Memory-mapped, software visible timer registers
/// Timer N Configuration and Capability Register
@ -181,32 +181,34 @@ pub struct HPETTimer {
}
impl HPETTimer {
fn init(&mut self, index: usize, state_ptr: *mut HPETState) -> &mut Self {
*self = HPETTimer::default();
self.index = index;
self.state = NonNull::new(state_ptr);
self
}
fn init(&mut self, index: usize, state: &HPETState) {
*self = HPETTimer {
index,
qemu_timer: Timer::new(),
state: NonNull::new(state as *const _ as *mut _).unwrap(),
config: 0,
cmp: 0,
fsb: 0,
cmp64: 0,
period: 0,
wrap_flag: 0,
last: 0,
};
fn init_timer_with_state(&mut self) {
self.qemu_timer = Some(Box::new({
let mut t = Timer::new();
t.init_full(
None,
CLOCK_VIRTUAL,
Timer::NS,
0,
timer_handler,
&self.get_state().timers[self.index],
);
t
}));
self.qemu_timer.init_full(
None,
CLOCK_VIRTUAL,
Timer::NS,
0,
timer_handler,
&state.timers[self.index],
)
}
fn get_state(&self) -> &HPETState {
// SAFETY:
// the pointer is convertible to a reference
unsafe { self.state.unwrap().as_ref() }
unsafe { self.state.as_ref() }
}
fn is_int_active(&self) -> bool {
@ -330,7 +332,7 @@ impl HPETTimer {
}
self.last = ns;
self.qemu_timer.as_ref().unwrap().modify(self.last);
self.qemu_timer.modify(self.last);
}
fn set_timer(&mut self) {
@ -353,7 +355,7 @@ impl HPETTimer {
fn del_timer(&mut self) {
// Just remove the timer from the timer_list without destroying
// this timer instance.
self.qemu_timer.as_ref().unwrap().delete();
self.qemu_timer.delete();
if self.is_int_active() {
// For level-triggered interrupt, this leaves interrupt status
@ -581,13 +583,8 @@ impl HPETState {
}
fn init_timer(&self) {
let raw_ptr: *mut HPETState = self as *const HPETState as *mut HPETState;
for (index, timer) in self.timers.iter().enumerate() {
timer
.borrow_mut()
.init(index, raw_ptr)
.init_timer_with_state();
timer.borrow_mut().init(index, self);
}
}