From 4b66abead9c9c7b637fb87e6bf782a45eee2a621 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 23 May 2025 18:31:29 +0200
Subject: [PATCH] rust: qdev: support returning errors from realize

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/hw/char/pl011/src/device.rs |  5 +++--
 rust/hw/timer/hpet/src/device.rs |  5 +++--
 rust/qemu-api/src/qdev.rs        | 12 ++++++++----
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
index 0501fa5be9..be8387f6f2 100644
--- a/rust/hw/char/pl011/src/device.rs
+++ b/rust/hw/char/pl011/src/device.rs
@@ -175,7 +175,7 @@ impl DeviceImpl for PL011State {
     fn vmsd() -> Option<&'static VMStateDescription> {
         Some(&device_class::VMSTATE_PL011)
     }
-    const REALIZE: Option<fn(&Self)> = Some(Self::realize);
+    const REALIZE: Option<fn(&Self) -> qemu_api::Result<()>> = Some(Self::realize);
 }
 
 impl ResettablePhasesImpl for PL011State {
@@ -619,9 +619,10 @@ impl PL011State {
         }
     }
 
-    fn realize(&self) {
+    fn realize(&self) -> qemu_api::Result<()> {
         self.char_backend
             .enable_handlers(self, Self::can_receive, Self::receive, Self::event);
+        Ok(())
     }
 
     fn reset_hold(&self, _type: ResetType) {
diff --git a/rust/hw/timer/hpet/src/device.rs b/rust/hw/timer/hpet/src/device.rs
index e3ba62b287..68c82b09b6 100644
--- a/rust/hw/timer/hpet/src/device.rs
+++ b/rust/hw/timer/hpet/src/device.rs
@@ -724,7 +724,7 @@ impl HPETState {
         }
     }
 
-    fn realize(&self) {
+    fn realize(&self) -> qemu_api::Result<()> {
         if self.int_route_cap == 0 {
             // TODO: Add error binding: warn_report()
             println!("Hpet's hpet-intcap property not initialized");
@@ -751,6 +751,7 @@ impl HPETState {
 
         self.init_gpio_in(2, HPETState::handle_legacy_irq);
         self.init_gpio_out(from_ref(&self.pit_enabled));
+        Ok(())
     }
 
     fn reset_hold(&self, _type: ResetType) {
@@ -1042,7 +1043,7 @@ impl DeviceImpl for HPETState {
         Some(&VMSTATE_HPET)
     }
 
-    const REALIZE: Option<fn(&Self)> = Some(Self::realize);
+    const REALIZE: Option<fn(&Self) -> qemu_api::Result<()>> = Some(Self::realize);
 }
 
 impl ResettablePhasesImpl for HPETState {
diff --git a/rust/qemu-api/src/qdev.rs b/rust/qemu-api/src/qdev.rs
index 1279d7a58d..0610959f46 100644
--- a/rust/qemu-api/src/qdev.rs
+++ b/rust/qemu-api/src/qdev.rs
@@ -12,10 +12,11 @@ use std::{
 pub use bindings::{ClockEvent, DeviceClass, Property, ResetType};
 
 use crate::{
-    bindings::{self, qdev_init_gpio_in, qdev_init_gpio_out, Error, ResettableClass},
+    bindings::{self, qdev_init_gpio_in, qdev_init_gpio_out, ResettableClass},
     callbacks::FnCall,
     cell::{bql_locked, Opaque},
     chardev::Chardev,
+    error::{Error, Result},
     irq::InterruptSource,
     prelude::*,
     qom::{ObjectClass, ObjectImpl, Owned},
@@ -108,7 +109,7 @@ pub trait DeviceImpl: ObjectImpl + ResettablePhasesImpl + IsA<DeviceState> {
     ///
     /// If not `None`, the parent class's `realize` method is overridden
     /// with the function pointed to by `REALIZE`.
-    const REALIZE: Option<fn(&Self)> = None;
+    const REALIZE: Option<fn(&Self) -> Result<()>> = None;
 
     /// An array providing the properties that the user can set on the
     /// device.  Not a `const` because referencing statics in constants
@@ -134,10 +135,13 @@ pub trait DeviceImpl: ObjectImpl + ResettablePhasesImpl + IsA<DeviceState> {
 /// readable/writeable from one thread at any time.
 unsafe extern "C" fn rust_realize_fn<T: DeviceImpl>(
     dev: *mut bindings::DeviceState,
-    _errp: *mut *mut Error,
+    errp: *mut *mut bindings::Error,
 ) {
     let state = NonNull::new(dev).unwrap().cast::<T>();
-    T::REALIZE.unwrap()(unsafe { state.as_ref() });
+    let result = T::REALIZE.unwrap()(unsafe { state.as_ref() });
+    unsafe {
+        Error::ok_or_propagate(result, errp);
+    }
 }
 
 unsafe impl InterfaceType for ResettableClass {
-- 
2.39.5