From: Paolo Bonzini Date: Mon, 28 Oct 2024 09:29:27 +0000 (+0100) Subject: rust: qdev: move device_class_init! body to generic function, ClassInitImpl implement... X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8c80c472da6342c5924bc4ea7e87c77ca61477b8;p=qemu.git rust: qdev: move device_class_init! body to generic function, ClassInitImpl implementation to macro Use a trait to access the former parameters to device_class_init!. This allows hiding the details of the class_init implementation behind a generic function and makes higher-level functionality available from qemu_api. The implementation of ClassInitImpl is then the same for all devices and is easily macroized. Later on, we can remove the need to implement ClassInitImpl by hand for all device types, and stop making rust_device_class_init<>() public. While at it, document the members of DeviceImpl. Reviewed-by: Zhao Liu Signed-off-by: Paolo Bonzini --- diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs index 2384d4bcb9..28b1924337 100644 --- a/rust/hw/char/pl011/src/device.rs +++ b/rust/hw/char/pl011/src/device.rs @@ -12,11 +12,13 @@ use qemu_api::{ bindings::{self, *}, c_str, definitions::ObjectImpl, - device_class::TYPE_SYS_BUS_DEVICE, + device_class::{DeviceImpl, TYPE_SYS_BUS_DEVICE}, + impl_device_class, irq::InterruptSource, }; use crate::{ + device_class, memory_ops::PL011_OPS, registers::{self, Interrupt}, RegisterOffset, @@ -116,14 +118,20 @@ pub struct PL011Class { _inner: [u8; 0], } -impl qemu_api::definitions::ClassInitImpl for PL011State { - const CLASS_INIT: Option = - Some(crate::device_class::pl011_class_init); - const CLASS_BASE_INIT: Option< - unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut c_void), - > = None; +impl DeviceImpl for PL011State { + fn properties() -> &'static [Property] { + &device_class::PL011_PROPERTIES + } + fn vmsd() -> Option<&'static VMStateDescription> { + Some(&device_class::VMSTATE_PL011) + } + const REALIZE: Option = + Some(device_class::pl011_realize); + const RESET: Option = Some(device_class::pl011_reset); } +impl_device_class!(PL011State); + impl PL011State { /// Initializes a pre-allocated, unitialized instance of `PL011State`. /// @@ -649,17 +657,13 @@ pub unsafe extern "C" fn pl011_luminary_init(obj: *mut Object) { } } -impl qemu_api::definitions::ClassInitImpl for PL011Luminary { - const CLASS_INIT: Option = - None; - const CLASS_BASE_INIT: Option< - unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut c_void), - > = None; -} - impl ObjectImpl for PL011Luminary { type Class = PL011LuminaryClass; const TYPE_NAME: &'static CStr = crate::TYPE_PL011_LUMINARY; const PARENT_TYPE_NAME: Option<&'static CStr> = Some(crate::TYPE_PL011); const INSTANCE_INIT: Option = Some(pl011_luminary_init); } + +impl DeviceImpl for PL011Luminary {} + +impl_device_class!(PL011Luminary); diff --git a/rust/hw/char/pl011/src/device_class.rs b/rust/hw/char/pl011/src/device_class.rs index a707fde138..c61b6bb025 100644 --- a/rust/hw/char/pl011/src/device_class.rs +++ b/rust/hw/char/pl011/src/device_class.rs @@ -93,14 +93,6 @@ qemu_api::declare_properties! { ), } -qemu_api::device_class_init! { - pl011_class_init, - props => PL011_PROPERTIES, - realize_fn => Some(pl011_realize), - legacy_reset_fn => Some(pl011_reset), - vmsd => VMSTATE_PL011, -} - /// # Safety /// /// We expect the FFI user of this function to pass a valid pointer, that has diff --git a/rust/qemu-api/src/device_class.rs b/rust/qemu-api/src/device_class.rs index 922bbce1bb..f683f94f2a 100644 --- a/rust/qemu-api/src/device_class.rs +++ b/rust/qemu-api/src/device_class.rs @@ -2,25 +2,80 @@ // Author(s): Manos Pitsidianakis // SPDX-License-Identifier: GPL-2.0-or-later -use std::ffi::CStr; +use std::{ffi::CStr, os::raw::c_void}; -use crate::bindings; +use crate::{ + bindings::{self, DeviceClass, DeviceState, Error, ObjectClass, Property, VMStateDescription}, + zeroable::Zeroable, +}; + +/// Trait providing the contents of [`DeviceClass`]. +pub trait DeviceImpl { + /// _Realization_ is the second stage of device creation. It contains + /// all operations that depend on device properties and can fail (note: + /// this is not yet supported for Rust devices). + /// + /// If not `None`, the parent class's `realize` method is overridden + /// with the function pointed to by `REALIZE`. + const REALIZE: Option = None; + + /// If not `None`, the parent class's `reset` method is overridden + /// with the function pointed to by `RESET`. + /// + /// Rust does not yet support the three-phase reset protocol; this is + /// usually okay for leaf classes. + const RESET: Option = None; + + /// An array providing the properties that the user can set on the + /// device. Not a `const` because referencing statics in constants + /// is unstable until Rust 1.83.0. + fn properties() -> &'static [Property] { + &[Zeroable::ZERO; 1] + } + + /// A `VMStateDescription` providing the migration format for the device + /// Not a `const` because referencing statics in constants is unstable + /// until Rust 1.83.0. + fn vmsd() -> Option<&'static VMStateDescription> { + None + } +} + +/// # Safety +/// +/// We expect the FFI user of this function to pass a valid pointer that +/// can be downcasted to type `DeviceClass`, because `T` implements +/// `DeviceImpl`. +pub unsafe extern "C" fn rust_device_class_init( + klass: *mut ObjectClass, + _: *mut c_void, +) { + let mut dc = ::core::ptr::NonNull::new(klass.cast::()).unwrap(); + unsafe { + let dc = dc.as_mut(); + if let Some(realize_fn) = ::REALIZE { + dc.realize = Some(realize_fn); + } + if let Some(reset_fn) = ::RESET { + bindings::device_class_set_legacy_reset(dc, Some(reset_fn)); + } + if let Some(vmsd) = ::vmsd() { + dc.vmsd = vmsd; + } + bindings::device_class_set_props(dc, ::properties().as_ptr()); + } +} #[macro_export] -macro_rules! device_class_init { - ($func:ident, props => $props:ident, realize_fn => $realize_fn:expr, legacy_reset_fn => $legacy_reset_fn:expr, vmsd => $vmsd:ident$(,)*) => { - pub unsafe extern "C" fn $func( - klass: *mut $crate::bindings::ObjectClass, - _: *mut ::std::os::raw::c_void, - ) { - let mut dc = - ::core::ptr::NonNull::new(klass.cast::<$crate::bindings::DeviceClass>()).unwrap(); - unsafe { - dc.as_mut().realize = $realize_fn; - dc.as_mut().vmsd = &$vmsd; - $crate::bindings::device_class_set_legacy_reset(dc.as_mut(), $legacy_reset_fn); - $crate::bindings::device_class_set_props(dc.as_mut(), $props.as_ptr()); - } +macro_rules! impl_device_class { + ($type:ty) => { + impl $crate::definitions::ClassInitImpl for $type { + const CLASS_INIT: Option< + unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut ::std::os::raw::c_void), + > = Some($crate::device_class::rust_device_class_init::<$type>); + const CLASS_BASE_INIT: Option< + unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut ::std::os::raw::c_void), + > = None; } }; } diff --git a/rust/qemu-api/tests/tests.rs b/rust/qemu-api/tests/tests.rs index fd0c979121..b8b12a4042 100644 --- a/rust/qemu-api/tests/tests.rs +++ b/rust/qemu-api/tests/tests.rs @@ -2,13 +2,14 @@ // Author(s): Manos Pitsidianakis // SPDX-License-Identifier: GPL-2.0-or-later -use std::{ffi::CStr, os::raw::c_void}; +use std::ffi::CStr; use qemu_api::{ bindings::*, c_str, declare_properties, define_property, - definitions::{ClassInitImpl, ObjectImpl}, - device_class, device_class_init, + definitions::ObjectImpl, + device_class::{self, DeviceImpl}, + impl_device_class, zeroable::Zeroable, }; @@ -45,28 +46,23 @@ fn test_device_decl_macros() { ), } - device_class_init! { - dummy_class_init, - props => DUMMY_PROPERTIES, - realize_fn => None, - legacy_reset_fn => None, - vmsd => VMSTATE, - } - impl ObjectImpl for DummyState { type Class = DummyClass; const TYPE_NAME: &'static CStr = c_str!("dummy"); const PARENT_TYPE_NAME: Option<&'static CStr> = Some(device_class::TYPE_DEVICE); } - impl ClassInitImpl for DummyState { - const CLASS_INIT: Option = - Some(dummy_class_init); - const CLASS_BASE_INIT: Option< - unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut c_void), - > = None; + impl DeviceImpl for DummyState { + fn properties() -> &'static [Property] { + &DUMMY_PROPERTIES + } + fn vmsd() -> Option<&'static VMStateDescription> { + Some(&VMSTATE) + } } + impl_device_class!(DummyState); + unsafe { module_call_init(module_init_type::MODULE_INIT_QOM); object_unref(object_new(DummyState::TYPE_NAME.as_ptr()).cast());