rust: move hwcore::sysbus to system crate

This inverts the dependency from hwcore to system, replacing it with
a dependency from system to hwcore.  It also matches how hw/core/sysbus.h
is part of the system-sys crate, and hw/core/sysbus.c is part of system_ss
on the C side.

This fixes a linker error in hwcore integration tests on msys2.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust/hw/core/Cargo.toml

@@ -21,7 +21,6 @@ bql = { path = "../../bql" }
 qom = { path = "../../qom" }
 chardev = { path = "../../chardev" }
 migration = { path = "../../migration" }
-system = { path = "../../system" }
 util = { path = "../../util" }
 
 [lints]

rust/hw/core/meson.build

@@ -3,7 +3,7 @@ _hwcore_rs = static_library(
   'src/lib.rs',
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
-  link_with: [_bql_rs, _chardev_rs, _migration_rs, _qom_rs, _system_rs, _util_rs],
+  link_with: [_bql_rs, _chardev_rs, _migration_rs, _qom_rs, _util_rs],
   dependencies: [glib_sys_rs, qemu_macros, common_rs, hwcore_sys_rs],
 )
 

rust/hw/core/src/irq.rs

@@ -33,10 +33,10 @@
 ///
 /// Interrupts are implemented as a pointer to the interrupt "sink", which has
 /// type [`IRQState`].  A device exposes its source as a QOM link property using
-/// a function such as [`crate::sysbus::SysBusDeviceMethods::init_irq`], and
+/// a function such as [`crate::DeviceMethods::init_gpio_out`], and
 /// initially leaves the pointer to a NULL value, representing an unconnected
 /// interrupt. To connect it, whoever creates the device fills the pointer with
-/// the sink's `IRQState *`, for example using `sysbus_connect_irq`.  Because
+/// the sink's `IRQState *`, for example using `qdev_connect_gpio_out`.  Because
 /// devices are generally shared objects, interrupt sources are an example of
 /// the interior mutability pattern.
 ///
@@ -87,11 +87,11 @@ pub fn set(&self, level: T) {
         }
     }
 
-    pub(crate) const fn as_ptr(&self) -> *mut *mut bindings::IRQState {
+    pub const fn as_ptr(&self) -> *mut *mut bindings::IRQState {
         self.cell.as_ptr()
     }
 
-    pub(crate) const fn slice_as_ptr(slice: &[Self]) -> *mut *mut bindings::IRQState {
+    pub const fn slice_as_ptr(slice: &[Self]) -> *mut *mut bindings::IRQState {
         assert!(!slice.is_empty());
         slice[0].as_ptr()
     }

rust/hw/core/src/lib.rs

@@ -14,6 +14,3 @@
 
 mod qdev;
 pub use qdev::*;
-
-mod sysbus;
-pub use sysbus::*;

rust/hw/core/src/prelude.rs

@@ -9,9 +9,4 @@
 pub use crate::qdev::ResettablePhasesImpl;
 pub use crate::qdev::ResetType;
 
-pub use crate::sysbus::SysBusDevice;
-pub use crate::sysbus::SysBusDeviceClassExt;
-pub use crate::sysbus::SysBusDeviceImpl;
-pub use crate::sysbus::SysBusDeviceMethods;
-
 pub use crate::irq::InterruptSource;

rust/hw/core/tests/tests.rs

@@ -142,7 +142,7 @@ fn test_cast() {
     let obj_ref: &Object = p_ref.upcast();
     assert_eq!(addr_of!(*obj_ref), p_ptr.cast());
 
-    let sbd_ref: Option<&SysBusDevice> = obj_ref.dynamic_cast();
+    let sbd_ref: Option<&DummyChildState> = obj_ref.dynamic_cast();
     assert!(sbd_ref.is_none());
 
     let dev_ref: Option<&DeviceState> = obj_ref.downcast();
@@ -150,7 +150,7 @@ fn test_cast() {
 
     // SAFETY: the cast is wrong, but the value is only used for comparison
     unsafe {
-        let sbd_ref: &SysBusDevice = obj_ref.unsafe_cast();
+        let sbd_ref: &DummyChildState = obj_ref.unsafe_cast();
         assert_eq!(addr_of!(*sbd_ref), p_ptr.cast());
     }
 }

rust/meson.build

@@ -42,9 +42,9 @@ subdir('util')
 subdir('bql')
 subdir('migration')
 subdir('qom')
-subdir('system')
 subdir('chardev')
 subdir('hw/core')
+subdir('system')
 subdir('tests')
 subdir('trace')
 subdir('hw')

rust/system/Cargo.toml

@@ -16,6 +16,7 @@ rust-version.workspace = true
 common = { path = "../common" }
 system-sys = { path = "../bindings/system-sys" }
 bql = { path = "../bql" }
+hwcore = { path = "../hw/core" }
 migration = { path = "../migration" }
 qom = { path = "../qom" }
 util = { path = "../util" }

rust/system/meson.build

@@ -1,7 +1,7 @@
 _system_rs = static_library(
   'system',
   'src/lib.rs',
-  link_with: [_bql_rs, _migration_rs, _qom_rs, _util_rs],
+  link_with: [_bql_rs, _hwcore_rs, _migration_rs, _qom_rs, _util_rs],
   dependencies: [glib_sys_rs, common_rs, qemu_macros, system_sys_rs],
 )
 

rust/system/src/lib.rs

@@ -9,3 +9,6 @@
 // for prelude-like modules
 #[rustfmt::skip]
 pub mod prelude;
+
+mod sysbus;
+pub use sysbus::*;

rust/system/src/prelude.rs

@@ -6,3 +6,8 @@
 pub use crate::memory::MemoryRegionOps;
 pub use crate::memory::MemoryRegionOpsBuilder;
 pub use crate::memory::MemTxAttrs;
+
+pub use crate::sysbus::SysBusDevice;
+pub use crate::sysbus::SysBusDeviceClassExt;
+pub use crate::sysbus::SysBusDeviceImpl;
+pub use crate::sysbus::SysBusDeviceMethods;

rust/system/src/sysbus.rs

@@ -7,15 +7,12 @@
 use std::ffi::CStr;
 
 use common::Opaque;
+use hwcore::{prelude::*, IRQState};
 use qom::prelude::*;
-use system::MemoryRegion;
 pub use system_sys::SysBusDeviceClass;
 use util::{Error, Result};
 
-use crate::{
-    irq::{IRQState, InterruptSource},
-    qdev::{DeviceClassExt, DeviceImpl, DeviceState},
-};
+use crate::MemoryRegion;
 
 /// A safe wrapper around [`system_sys::SysBusDevice`].
 #[repr(transparent)]