Wrap qdev_init_gpio_{in|out} as methods in DeviceMethods. And for
qdev_init_gpio_in, based on FnCall, it can support idiomatic Rust
callback without the need for C style wrapper.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
Changes since RFC:
* Use FnCall to support gpio in callback.
* Place gpio_{in|out} in DeviceMethods.
* Accept &[InterruptSource] as the parameter of gpio_out.
---
rust/qemu-api/src/qdev.rs | 37 +++++++++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)
diff --git a/rust/qemu-api/src/qdev.rs b/rust/qemu-api/src/qdev.rs
index 32740c873604..96ca8b8aa9ad 100644
--- a/rust/qemu-api/src/qdev.rs
+++ b/rust/qemu-api/src/qdev.rs
@@ -6,16 +6,17 @@
use std::{
ffi::{CStr, CString},
- os::raw::c_void,
+ os::raw::{c_int, c_void},
ptr::NonNull,
};
pub use bindings::{Clock, ClockEvent, DeviceClass, DeviceState, Property, ResetType};
use crate::{
- bindings::{self, Error, ResettableClass},
+ bindings::{self, qdev_init_gpio_in, qdev_init_gpio_out, Error, ResettableClass},
callbacks::FnCall,
cell::bql_locked,
+ irq::{IRQState, InterruptSource},
prelude::*,
qom::{ClassInitImpl, ObjectClass, ObjectImpl, Owned},
vmstate::VMStateDescription,
@@ -278,6 +279,38 @@ fn do_init_clock_in(
// IsA<DeviceState> bound.
do_init_clock_in(unsafe { self.as_mut_ptr() }, name, cb, events)
}
+
+ fn init_gpio_in<F: for<'a> FnCall<(&'a Self::Target, u32, u32)>>(&self, num_lines: u32, _f: F) {
+ unsafe extern "C" fn rust_irq_handler<T, F: for<'a> FnCall<(&'a T, u32, u32)>>(
+ opaque: *mut c_void,
+ line: c_int,
+ level: c_int,
+ ) {
+ // SAFETY: the opaque was passed as a reference to `T`
+ F::call((unsafe { &*(opaque.cast::<T>()) }, line as u32, level as u32))
+ }
+
+ let gpio_in_cb: unsafe extern "C" fn(*mut c_void, c_int, c_int) =
+ rust_irq_handler::<Self::Target, F>;
+
+ unsafe {
+ qdev_init_gpio_in(
+ self.as_mut_ptr::<DeviceState>(),
+ Some(gpio_in_cb),
+ num_lines as c_int,
+ );
+ }
+ }
+
+ fn init_gpio_out(&self, pins: &[InterruptSource]) {
+ unsafe {
+ qdev_init_gpio_out(
+ self.as_mut_ptr::<DeviceState>(),
+ InterruptSource::as_slice_of_qemu_irq(pins).as_ptr() as *mut *mut IRQState,
+ pins.len() as c_int,
+ );
+ }
+ }
}
impl<R: ObjectDeref> DeviceMethods for R where R::Target: IsA<DeviceState> {}
--
2.34.1
On Sat, Jan 25, 2025 at 1:32 PM Zhao Liu <zhao1.liu@intel.com> wrote:
> + fn init_gpio_in<F: for<'a> FnCall<(&'a Self::Target, u32, u32)>>(&self, num_lines: u32, _f: F) {
> + unsafe extern "C" fn rust_irq_handler<T, F: for<'a> FnCall<(&'a T, u32, u32)>>(
> + opaque: *mut c_void,
> + line: c_int,
> + level: c_int,
> + ) {
> + // SAFETY: the opaque was passed as a reference to `T`
> + F::call((unsafe { &*(opaque.cast::<T>()) }, line as u32, level as u32))
> + }
> +
> + let gpio_in_cb: unsafe extern "C" fn(*mut c_void, c_int, c_int) =
> + rust_irq_handler::<Self::Target, F>;
Please add "let _: () = F::ASSERT_IS_SOME;", which is added by the
qdev_init_clock_in() patch.
Paolo
On Wed, Jan 29, 2025 at 11:59:04AM +0100, Paolo Bonzini wrote:
> Date: Wed, 29 Jan 2025 11:59:04 +0100
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: Re: [PATCH 04/10] rust: add bindings for gpio_{in|out}
> initialization
>
>
>
> On Sat, Jan 25, 2025 at 1:32 PM Zhao Liu <zhao1.liu@intel.com> wrote:
> > + fn init_gpio_in<F: for<'a> FnCall<(&'a Self::Target, u32, u32)>>(&self, num_lines: u32, _f: F) {
> > + unsafe extern "C" fn rust_irq_handler<T, F: for<'a> FnCall<(&'a T, u32, u32)>>(
> > + opaque: *mut c_void,
> > + line: c_int,
> > + level: c_int,
> > + ) {
> > + // SAFETY: the opaque was passed as a reference to `T`
> > + F::call((unsafe { &*(opaque.cast::<T>()) }, line as u32, level as u32))
> > + }
> > +
> > + let gpio_in_cb: unsafe extern "C" fn(*mut c_void, c_int, c_int) =
> > + rust_irq_handler::<Self::Target, F>;
>
> Please add "let _: () = F::ASSERT_IS_SOME;", which is added by the
> qdev_init_clock_in() patch.
>
Okay.
I would add `assert!(F::is_some());` at the beginning of init_gpio_in().
There's a difference with origianl C version:
In C side, qdev_get_gpio_in() family could accept a NULL handler, but
there's no such case in current QEMU:
* qdev_get_gpio_in
* qdev_init_gpio_in_named
* qdev_init_gpio_in_named_with_opaque
And from code logic view, creating an input GPIO line but doing nothing
on input, sounds also unusual.
So, for simplicity, in the Rust version I make the handler non-optional.
Il ven 7 feb 2025, 09:24 Zhao Liu <zhao1.liu@intel.com> ha scritto: > > Please add "let _: () = F::ASSERT_IS_SOME;", which is added by the > > qdev_init_clock_in() patch. > > > > Okay. > > I would add `assert!(F::is_some());` at the beginning of init_gpio_in(). > Use the "let" so that it's caught at compile time. There's a difference with origianl C version: > > In C side, qdev_get_gpio_in() family could accept a NULL handler, but > there's no such case in current QEMU: > > * qdev_get_gpio_in > * qdev_init_gpio_in_named > * qdev_init_gpio_in_named_with_opaque > > And from code logic view, creating an input GPIO line but doing nothing > on input, sounds also unusual. > Wouldn't it then crash in qemu_set_irq? Paolo So, for simplicity, in the Rust version I make the handler non-optional. > > >
> Use the "let" so that it's caught at compile time. Thanks! Fixed. > There's a difference with origianl C version: > > > > In C side, qdev_get_gpio_in() family could accept a NULL handler, but > > there's no such case in current QEMU: > > > > * qdev_get_gpio_in > > * qdev_init_gpio_in_named > > * qdev_init_gpio_in_named_with_opaque > > > > And from code logic view, creating an input GPIO line but doing nothing > > on input, sounds also unusual. > > > > Wouldn't it then crash in qemu_set_irq? > Yes! Thank you for the education. Regards, Zhao
© 2016 - 2025 Red Hat, Inc.