The basic object lifecycle test can now be implemented using safe code!
Reviewed-by: Zhao Liu <zhao1....@intel.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
rust/hw/char/pl011/src/device.rs | 23 ++++++++++++---------
rust/qemu-api/src/prelude.rs | 1 +
rust/qemu-api/src/qom.rs | 23 +++++++++++++++++++--
rust/qemu-api/tests/tests.rs | 35 ++++++++++++--------------------
4 files changed, 48 insertions(+), 34 deletions(-)
diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
index 8050ede9c85..f5db114b0c7 100644
--- a/rust/hw/char/pl011/src/device.rs
+++ b/rust/hw/char/pl011/src/device.rs
@@ -10,11 +10,11 @@
use qemu_api::{
bindings::{
- error_fatal, hwaddr, memory_region_init_io, qdev_init_clock_in,
qdev_new,
- qdev_prop_set_chr, qemu_chr_fe_accept_input, qemu_chr_fe_ioctl,
qemu_chr_fe_set_handlers,
- qemu_chr_fe_write_all, qemu_irq, sysbus_connect_irq, sysbus_mmio_map,
- sysbus_realize_and_unref, CharBackend, Chardev, Clock, ClockEvent,
MemoryRegion,
- QEMUChrEvent, CHR_IOCTL_SERIAL_SET_BREAK,
+ error_fatal, hwaddr, memory_region_init_io, qdev_init_clock_in,
qdev_prop_set_chr,
+ qemu_chr_fe_accept_input, qemu_chr_fe_ioctl, qemu_chr_fe_set_handlers,
+ qemu_chr_fe_write_all, qemu_irq, sysbus_connect_irq, sysbus_mmio_map,
sysbus_realize,
+ CharBackend, Chardev, Clock, ClockEvent, MemoryRegion, QEMUChrEvent,
+ CHR_IOCTL_SERIAL_SET_BREAK,
},
c_str, impl_vmstate_forward,
irq::InterruptSource,
@@ -705,15 +705,18 @@ pub fn post_load(&self, _version_id: u32) -> Result<(),
()> {
irq: qemu_irq,
chr: *mut Chardev,
) -> *mut DeviceState {
+ let pl011 = PL011State::new();
unsafe {
- let dev: *mut DeviceState = qdev_new(PL011State::TYPE_NAME.as_ptr());
- let sysbus: *mut SysBusDevice = dev.cast::<SysBusDevice>();
-
+ let dev = pl011.as_mut_ptr::<DeviceState>();
qdev_prop_set_chr(dev, c_str!("chardev").as_ptr(), chr);
- sysbus_realize_and_unref(sysbus, addr_of_mut!(error_fatal));
+
+ let sysbus = pl011.as_mut_ptr::<SysBusDevice>();
+ sysbus_realize(sysbus, addr_of_mut!(error_fatal));
sysbus_mmio_map(sysbus, 0, addr);
sysbus_connect_irq(sysbus, 0, irq);
- dev
+
+ // return the pointer, which is kept alive by the QOM tree; drop owned
ref
+ pl011.as_mut_ptr()
}
}
diff --git a/rust/qemu-api/src/prelude.rs b/rust/qemu-api/src/prelude.rs
index 2dc86e19b29..3df6a5c21ec 100644
--- a/rust/qemu-api/src/prelude.rs
+++ b/rust/qemu-api/src/prelude.rs
@@ -12,6 +12,7 @@
pub use crate::qom::ObjectCast;
pub use crate::qom::ObjectCastMut;
pub use crate::qom::ObjectDeref;
+pub use crate::qom::ObjectClassMethods;
pub use crate::qom::ObjectMethods;
pub use crate::qom::ObjectType;
diff --git a/rust/qemu-api/src/qom.rs b/rust/qemu-api/src/qom.rs
index 404446d57fc..3e63cb30ca6 100644
--- a/rust/qemu-api/src/qom.rs
+++ b/rust/qemu-api/src/qom.rs
@@ -66,8 +66,8 @@
use crate::{
bindings::{
- self, object_dynamic_cast, object_get_class, object_get_typename,
object_ref, object_unref,
- TypeInfo,
+ self, object_dynamic_cast, object_get_class, object_get_typename,
object_new, object_ref,
+ object_unref, TypeInfo,
},
cell::bql_locked,
};
@@ -759,6 +759,24 @@ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
}
}
+/// Trait for class methods exposed by the Object class. The methods can be
+/// called on all objects that have the trait `IsA<Object>`.
+///
+/// The trait should only be used through the blanket implementation,
+/// which guarantees safety via `IsA`
+pub trait ObjectClassMethods: IsA<Object> {
+ /// Return a new reference counted instance of this class
+ fn new() -> Owned<Self> {
+ assert!(bql_locked());
+ // SAFETY: the object created by object_new is allocated on
+ // the heap and has a reference count of 1
+ unsafe {
+ let obj = &*object_new(Self::TYPE_NAME.as_ptr());
+ Owned::from_raw(obj.unsafe_cast::<Self>())
+ }
+ }
+}
+
/// Trait for methods exposed by the Object class. The methods can be
/// called on all objects that have the trait `IsA<Object>`.
///
@@ -799,4 +817,5 @@ fn debug_fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
}
}
+impl<T> ObjectClassMethods for T where T: IsA<Object> {}
impl<R: ObjectDeref> ObjectMethods for R where R::Target: IsA<Object> {}
diff --git a/rust/qemu-api/tests/tests.rs b/rust/qemu-api/tests/tests.rs
index 5f6096a572e..10748fba197 100644
--- a/rust/qemu-api/tests/tests.rs
+++ b/rust/qemu-api/tests/tests.rs
@@ -3,8 +3,7 @@
// SPDX-License-Identifier: GPL-2.0-or-later
use std::{
- ffi::CStr,
- os::raw::c_void,
+ ffi::{c_void, CStr},
ptr::{addr_of, addr_of_mut},
};
@@ -15,7 +14,7 @@
declare_properties, define_property,
prelude::*,
qdev::{DeviceClass, DeviceImpl, DeviceState, Property},
- qom::{ClassInitImpl, ObjectImpl, Owned, ParentField},
+ qom::{ClassInitImpl, ObjectImpl, ParentField},
vmstate::VMStateDescription,
zeroable::Zeroable,
};
@@ -132,10 +131,8 @@ fn init_qom() {
/// Create and immediately drop an instance.
fn test_object_new() {
init_qom();
- unsafe {
- object_unref(object_new(DummyState::TYPE_NAME.as_ptr()).cast());
- object_unref(object_new(DummyChildState::TYPE_NAME.as_ptr()).cast());
- }
+ drop(DummyState::new());
+ drop(DummyChildState::new());
}
#[test]
@@ -143,8 +140,7 @@ fn test_object_new() {
/// Create, clone and then drop an instance.
fn test_clone() {
init_qom();
- let p: *mut DummyState = unsafe {
object_new(DummyState::TYPE_NAME.as_ptr()).cast() };
- let p = unsafe { Owned::from_raw(p) };
+ let p = DummyState::new();
assert_eq!(p.clone().typename(), "dummy");
drop(p);
}
@@ -153,12 +149,8 @@ fn test_clone() {
/// Try invoking a method on an object.
fn test_typename() {
init_qom();
- let p: *mut DummyState = unsafe {
object_new(DummyState::TYPE_NAME.as_ptr()).cast() };
- let p_ref: &DummyState = unsafe { &*p };
- assert_eq!(p_ref.typename(), "dummy");
- unsafe {
- object_unref(p_ref.as_object_mut_ptr().cast::<c_void>());
- }
+ let p = DummyState::new();
+ assert_eq!(p.typename(), "dummy");
}
// a note on all "cast" tests: usually, especially for downcasts the desired
@@ -173,24 +165,23 @@ fn test_typename() {
/// Test casts on shared references.
fn test_cast() {
init_qom();
- let p: *mut DummyState = unsafe {
object_new(DummyState::TYPE_NAME.as_ptr()).cast() };
+ let p = DummyState::new();
+ let p_ptr: *mut DummyState = p.as_mut_ptr();
+ let p_ref: &mut DummyState = unsafe { &mut *p_ptr };
- let p_ref: &DummyState = unsafe { &*p };
let obj_ref: &Object = p_ref.upcast();
- assert_eq!(addr_of!(*obj_ref), p.cast());
+ assert_eq!(addr_of!(*obj_ref), p_ptr.cast());
let sbd_ref: Option<&SysBusDevice> = obj_ref.dynamic_cast();
assert!(sbd_ref.is_none());
let dev_ref: Option<&DeviceState> = obj_ref.downcast();
- assert_eq!(addr_of!(*dev_ref.unwrap()), p.cast());
+ assert_eq!(addr_of!(*dev_ref.unwrap()), p_ptr.cast());
// SAFETY: the cast is wrong, but the value is only used for comparison
unsafe {
let sbd_ref: &SysBusDevice = obj_ref.unsafe_cast();
- assert_eq!(addr_of!(*sbd_ref), p.cast());
-
- object_unref(p_ref.as_object_mut_ptr().cast::<c_void>());
+ assert_eq!(addr_of!(*sbd_ref), p_ptr.cast());
}
}
--
2.48.1
