diff options
Diffstat (limited to 'rust/qemu-api/src')
| -rw-r--r-- | rust/qemu-api/src/device_class.rs | 87 |
1 files changed, 71 insertions, 16 deletions
diff --git a/rust/qemu-api/src/device_class.rs b/rust/qemu-api/src/device_class.rs index 922bbce..f683f94 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 <manos.pitsidianakis@linaro.org> // 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<unsafe extern "C" fn(*mut DeviceState, *mut *mut Error)> = 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<unsafe extern "C" fn(dev: *mut DeviceState)> = 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<T: DeviceImpl>( + klass: *mut ObjectClass, + _: *mut c_void, +) { + let mut dc = ::core::ptr::NonNull::new(klass.cast::<DeviceClass>()).unwrap(); + unsafe { + let dc = dc.as_mut(); + if let Some(realize_fn) = <T as DeviceImpl>::REALIZE { + dc.realize = Some(realize_fn); + } + if let Some(reset_fn) = <T as DeviceImpl>::RESET { + bindings::device_class_set_legacy_reset(dc, Some(reset_fn)); + } + if let Some(vmsd) = <T as DeviceImpl>::vmsd() { + dc.vmsd = vmsd; + } + bindings::device_class_set_props(dc, <T as DeviceImpl>::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; } }; } |