* [PATCH 01/11] rust: bql: add BqlRefCell::get_mut()
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-13 8:49 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 02/11] rust: migration: do not pass raw pointer to VMStateDescription::fields Paolo Bonzini
` (24 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
This method is rarely useful in QEMU due to the pervasiveness of
shared references, but add it for when a &mut BqlRefCell<> is used.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/bql/src/cell.rs | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/rust/bql/src/cell.rs b/rust/bql/src/cell.rs
index 24ab294b60d..54cfe6145c5 100644
--- a/rust/bql/src/cell.rs
+++ b/rust/bql/src/cell.rs
@@ -580,6 +580,23 @@ pub fn borrow_mut(&self) -> BqlRefMut<'_, T> {
}
}
+ /// Returns a mutable reference to the underlying data in this cell,
+ /// while the owner already has a mutable reference to the cell.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bql::BqlRefCell;
+ ///
+ /// let mut c = BqlRefCell::new(5);
+ ///
+ /// *c.get_mut() = 10;
+ /// ```
+ #[inline]
+ pub const fn get_mut(&mut self) -> &mut T {
+ self.value.get_mut()
+ }
+
/// Returns a raw pointer to the underlying data in this cell.
///
/// # Examples
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 01/11] rust: bql: add BqlRefCell::get_mut()
2025-10-01 7:52 ` [PATCH 01/11] rust: bql: add BqlRefCell::get_mut() Paolo Bonzini
@ 2025-10-13 8:49 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 8:49 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:00AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:00 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 01/11] rust: bql: add BqlRefCell::get_mut()
> X-Mailer: git-send-email 2.51.0
>
> This method is rarely useful in QEMU due to the pervasiveness of
> shared references, but add it for when a &mut BqlRefCell<> is used.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/bql/src/cell.rs | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 02/11] rust: migration: do not pass raw pointer to VMStateDescription::fields
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
2025-10-01 7:52 ` [PATCH 01/11] rust: bql: add BqlRefCell::get_mut() Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-13 8:20 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 03/11] rust: migration: do not store raw pointers into VMStateSubsectionsWrapper Paolo Bonzini
` (23 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
Pass a slice instead; a function that accepts a raw pointer should
arguably be declared as unsafe.
But since it is now much easier to forget vmstate_fields!, validate the
value (at least to some extent) before passing it to C. (Unfortunately,
doing the same for subsections would require const ptr::is_null(), which
is only stable in Rust 1.84).
Suggested-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/migration/src/vmstate.rs | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index e04b19b3c9f..319d353c311 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -424,7 +424,7 @@ macro_rules! vmstate_fields {
..::common::zeroable::Zeroable::ZERO
}
];
- _FIELDS.as_ptr()
+ _FIELDS
}}
}
@@ -676,8 +676,11 @@ pub const fn unplug_pending<F: for<'a> FnCall<(&'a T,), bool>>(mut self, _f: &F)
}
#[must_use]
- pub const fn fields(mut self, fields: *const VMStateField) -> Self {
- self.0.fields = fields;
+ pub const fn fields(mut self, fields: &'static [VMStateField]) -> Self {
+ if fields[fields.len() - 1].flags.0 != VMStateFlags::VMS_END.0 {
+ panic!("fields are not terminated, use vmstate_fields!");
+ }
+ self.0.fields = fields.as_ptr();
self
}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 02/11] rust: migration: do not pass raw pointer to VMStateDescription::fields
2025-10-01 7:52 ` [PATCH 02/11] rust: migration: do not pass raw pointer to VMStateDescription::fields Paolo Bonzini
@ 2025-10-13 8:20 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 8:20 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:01AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:01 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 02/11] rust: migration: do not pass raw pointer to
> VMStateDescription::fields
> X-Mailer: git-send-email 2.51.0
>
> Pass a slice instead; a function that accepts a raw pointer should
> arguably be declared as unsafe.
>
> But since it is now much easier to forget vmstate_fields!, validate the
> value (at least to some extent) before passing it to C. (Unfortunately,
> doing the same for subsections would require const ptr::is_null(), which
> is only stable in Rust 1.84).
>
> Suggested-by: Zhao Liu <zhao1.liu@intel.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/migration/src/vmstate.rs | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 03/11] rust: migration: do not store raw pointers into VMStateSubsectionsWrapper
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
2025-10-01 7:52 ` [PATCH 01/11] rust: bql: add BqlRefCell::get_mut() Paolo Bonzini
2025-10-01 7:52 ` [PATCH 02/11] rust: migration: do not pass raw pointer to VMStateDescription::fields Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-13 8:46 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 04/11] rust: migration: validate termination of subsection arrays Paolo Bonzini
` (22 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
Raw pointers were used to insert a NULL one at the end of the array.
However, Option<&...> has the same layout and does not remove Sync
from the type of the array.
As an extra benefit, this enables validation of the terminator of the
subsection array, because is_null() in const context would not be stable
until Rust 1.84.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/migration/src/vmstate.rs | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index 319d353c311..6a89769984f 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -469,33 +469,21 @@ unsafe impl $crate::vmstate::VMState for $type {
};
}
-/// A transparent wrapper type for the `subsections` field of
-/// [`VMStateDescription`].
-///
-/// This is necessary to be able to declare subsection descriptions as statics,
-/// because the only way to implement `Sync` for a foreign type (and `*const`
-/// pointers are foreign types in Rust) is to create a wrapper struct and
-/// `unsafe impl Sync` for it.
-///
-/// This struct is used in the
-/// [`vm_state_subsections`](crate::vmstate_subsections) macro implementation.
-#[repr(transparent)]
-pub struct VMStateSubsectionsWrapper(pub &'static [*const crate::bindings::VMStateDescription]);
-
-unsafe impl Sync for VMStateSubsectionsWrapper {}
+/// The type returned by [`vmstate_subsections!`].
+pub type VMStateSubsections = &'static [Option<&'static crate::bindings::VMStateDescription>];
/// Helper macro to declare a list of subsections ([`VMStateDescription`])
/// into a static and return a pointer to the array of pointers it created.
#[macro_export]
macro_rules! vmstate_subsections {
($($subsection:expr),*$(,)*) => {{
- static _SUBSECTIONS: $crate::vmstate::VMStateSubsectionsWrapper = $crate::vmstate::VMStateSubsectionsWrapper(&[
+ static _SUBSECTIONS: $crate::vmstate::VMStateSubsections = &[
$({
static _SUBSECTION: $crate::bindings::VMStateDescription = $subsection.get();
- ::core::ptr::addr_of!(_SUBSECTION)
+ Some(&_SUBSECTION)
}),*,
- ::core::ptr::null()
- ]);
+ None,
+ ];
&_SUBSECTIONS
}}
}
@@ -685,8 +673,9 @@ pub const fn fields(mut self, fields: &'static [VMStateField]) -> Self {
}
#[must_use]
- pub const fn subsections(mut self, subs: &'static VMStateSubsectionsWrapper) -> Self {
- self.0.subsections = subs.0.as_ptr();
+ pub const fn subsections(mut self, subs: &'static VMStateSubsections) -> Self {
+ let subs: *const Option<&bindings::VMStateDescription> = subs.as_ptr();
+ self.0.subsections = subs.cast::<*const bindings::VMStateDescription>();
self
}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 03/11] rust: migration: do not store raw pointers into VMStateSubsectionsWrapper
2025-10-01 7:52 ` [PATCH 03/11] rust: migration: do not store raw pointers into VMStateSubsectionsWrapper Paolo Bonzini
@ 2025-10-13 8:46 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 8:46 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:02AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:02 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 03/11] rust: migration: do not store raw pointers into
> VMStateSubsectionsWrapper
> X-Mailer: git-send-email 2.51.0
>
> Raw pointers were used to insert a NULL one at the end of the array.
> However, Option<&...> has the same layout and does not remove Sync
> from the type of the array.
>
> As an extra benefit, this enables validation of the terminator of the
> subsection array, because is_null() in const context would not be stable
> until Rust 1.84.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/migration/src/vmstate.rs | 29 +++++++++--------------------
> 1 file changed, 9 insertions(+), 20 deletions(-)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 04/11] rust: migration: validate termination of subsection arrays
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (2 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 03/11] rust: migration: do not store raw pointers into VMStateSubsectionsWrapper Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-13 8:46 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 05/11] rust: migration: extract vmstate_fields_ref Paolo Bonzini
` (21 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
For consistency with fields(), validate the value (at least to some extent)
before passing it to C.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/migration/src/vmstate.rs | 3 +++
1 file changed, 3 insertions(+)
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index 6a89769984f..22799dffdc7 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -674,6 +674,9 @@ pub const fn fields(mut self, fields: &'static [VMStateField]) -> Self {
#[must_use]
pub const fn subsections(mut self, subs: &'static VMStateSubsections) -> Self {
+ if subs[subs.len() - 1].is_some() {
+ panic!("subsections are not terminated, use vmstate_subsections!");
+ }
let subs: *const Option<&bindings::VMStateDescription> = subs.as_ptr();
self.0.subsections = subs.cast::<*const bindings::VMStateDescription>();
self
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 04/11] rust: migration: validate termination of subsection arrays
2025-10-01 7:52 ` [PATCH 04/11] rust: migration: validate termination of subsection arrays Paolo Bonzini
@ 2025-10-13 8:46 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 8:46 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:03AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:03 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 04/11] rust: migration: validate termination of subsection
> arrays
> X-Mailer: git-send-email 2.51.0
>
> For consistency with fields(), validate the value (at least to some extent)
> before passing it to C.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/migration/src/vmstate.rs | 3 +++
> 1 file changed, 3 insertions(+)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 05/11] rust: migration: extract vmstate_fields_ref
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (3 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 04/11] rust: migration: validate termination of subsection arrays Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-13 8:55 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 06/11] rust: move VMState from bql to migration Paolo Bonzini
` (20 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
This is useful when building a VMState for generic structs, because you have
to avoid nested statics. Using vmstate_fields! will fail in the likely case
where the _FIELDS static uses Self from an outer item, because that is
forbidden.
The separate macros are needed because you cannot just do
.fields(vmstate_fields_ref! {
vmstate_of!(PL011State, clock),
})
The value returned by vmstate_fields_ref! is not promoted to static, which is
unfortunate but intentional (https://github.com/rust-lang/rust/issues/60502):
error[E0716]: temporary value dropped while borrowed
--> rust/hw/char/pl011/libpl011.rlib.p/structured/device.rs:743:17
|
738 | / VMStateDescriptionBuilder::<PL011State>::new()
739 | | .name(c"pl011/clock")
740 | | .version_id(1)
741 | | .minimum_version_id(1)
742 | | .needed(&PL011State::clock_needed)
743 | | .fields(vmstate_fields_ref! {
| | _________________^
744 | || vmstate_of!(PL011State, clock),
745 | || })
| ||_________^- argument requires that borrow lasts for `'static`
| |_________|
| creates a temporary value which is freed while still in use
746 | .build();
| - temporary value is freed at the end of this statement
Thus it is necessary to use the "static", whether explicitly or hidden by
vmstate_fields.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/migration/src/vmstate.rs | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index 22799dffdc7..2900ef1127a 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -411,19 +411,30 @@ const fn phantom__<T>(_: &T) -> ::core::marker::PhantomData<T> {
}};
}
+/// Add a terminator to the fields in the arguments, and return
+/// a reference to the resulting array of values.
+#[macro_export]
+macro_rules! vmstate_fields_ref {
+ ($($field:expr),*$(,)*) => {
+ &[
+ $($field),*,
+ $crate::bindings::VMStateField {
+ flags: $crate::bindings::VMStateFlags::VMS_END,
+ ..::common::zeroable::Zeroable::ZERO
+ }
+ ]
+ }
+}
+
/// Helper macro to declare a list of
/// ([`VMStateField`](`crate::bindings::VMStateField`)) into a static and return
/// a pointer to the array of values it created.
#[macro_export]
macro_rules! vmstate_fields {
($($field:expr),*$(,)*) => {{
- static _FIELDS: &[$crate::bindings::VMStateField] = &[
+ static _FIELDS: &[$crate::bindings::VMStateField] = $crate::vmstate_fields_ref!(
$($field),*,
- $crate::bindings::VMStateField {
- flags: $crate::bindings::VMStateFlags::VMS_END,
- ..::common::zeroable::Zeroable::ZERO
- }
- ];
+ );
_FIELDS
}}
}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 05/11] rust: migration: extract vmstate_fields_ref
2025-10-01 7:52 ` [PATCH 05/11] rust: migration: extract vmstate_fields_ref Paolo Bonzini
@ 2025-10-13 8:55 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 8:55 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:04AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:04 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 05/11] rust: migration: extract vmstate_fields_ref
> X-Mailer: git-send-email 2.51.0
>
> This is useful when building a VMState for generic structs, because you have
> to avoid nested statics. Using vmstate_fields! will fail in the likely case
> where the _FIELDS static uses Self from an outer item, because that is
> forbidden.
>
> The separate macros are needed because you cannot just do
>
> .fields(vmstate_fields_ref! {
> vmstate_of!(PL011State, clock),
> })
>
> The value returned by vmstate_fields_ref! is not promoted to static, which is
> unfortunate but intentional (https://github.com/rust-lang/rust/issues/60502):
>
> error[E0716]: temporary value dropped while borrowed
> --> rust/hw/char/pl011/libpl011.rlib.p/structured/device.rs:743:17
> |
> 738 | / VMStateDescriptionBuilder::<PL011State>::new()
> 739 | | .name(c"pl011/clock")
> 740 | | .version_id(1)
> 741 | | .minimum_version_id(1)
> 742 | | .needed(&PL011State::clock_needed)
> 743 | | .fields(vmstate_fields_ref! {
> | | _________________^
> 744 | || vmstate_of!(PL011State, clock),
> 745 | || })
> | ||_________^- argument requires that borrow lasts for `'static`
> | |_________|
> | creates a temporary value which is freed while still in use
> 746 | .build();
> | - temporary value is freed at the end of this statement
>
> Thus it is necessary to use the "static", whether explicitly or hidden by
> vmstate_fields.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/migration/src/vmstate.rs | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 06/11] rust: move VMState from bql to migration
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (4 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 05/11] rust: migration: extract vmstate_fields_ref Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-13 8:57 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 07/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (19 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
The high-level wrapper Migratable<T> will contain a BqlCell,
which would introduce a circular dependency betwen the bql and
migration crates. Move the implementation of VMState for cells
to "migration", together with the implementation for std types.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/Cargo.lock | 4 +---
rust/bql/Cargo.toml | 3 ---
rust/bql/meson.build | 1 -
rust/bql/src/cell.rs | 6 ------
rust/meson.build | 2 +-
rust/migration/Cargo.toml | 1 +
rust/migration/meson.build | 4 ++--
rust/migration/src/vmstate.rs | 2 ++
8 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 444ef516a70..008d6ca4d62 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -57,9 +57,6 @@ dependencies = [
[[package]]
name = "bql"
version = "0.1.0"
-dependencies = [
- "migration",
-]
[[package]]
name = "chardev"
@@ -141,6 +138,7 @@ checksum = "18d287de67fe55fd7e1581fe933d965a5a9477b38e949cfa9f8574ef01506398"
name = "migration"
version = "0.1.0"
dependencies = [
+ "bql",
"common",
"util",
]
diff --git a/rust/bql/Cargo.toml b/rust/bql/Cargo.toml
index 1041bd4ea93..d87edf4c302 100644
--- a/rust/bql/Cargo.toml
+++ b/rust/bql/Cargo.toml
@@ -12,9 +12,6 @@ license.workspace = true
repository.workspace = true
rust-version.workspace = true
-[dependencies]
-migration = { path = "../migration" }
-
[features]
default = ["debug_cell"]
debug_cell = []
diff --git a/rust/bql/meson.build b/rust/bql/meson.build
index bc51c7f160b..fedb94da9fd 100644
--- a/rust/bql/meson.build
+++ b/rust/bql/meson.build
@@ -37,7 +37,6 @@ _bql_rs = static_library(
override_options: ['rust_std=2021', 'build.rust_std=2021'],
rust_abi: 'rust',
rust_args: _bql_cfg,
- link_with: [_migration_rs],
)
bql_rs = declare_dependency(link_with: [_bql_rs],
diff --git a/rust/bql/src/cell.rs b/rust/bql/src/cell.rs
index 54cfe6145c5..8ade7db629c 100644
--- a/rust/bql/src/cell.rs
+++ b/rust/bql/src/cell.rs
@@ -151,8 +151,6 @@
ptr::NonNull,
};
-use migration::impl_vmstate_transparent;
-
/// A mutable memory location that is protected by the Big QEMU Lock.
///
/// # Memory layout
@@ -364,8 +362,6 @@ pub fn take(&self) -> T {
}
}
-impl_vmstate_transparent!(crate::cell::BqlCell<T> where T: VMState);
-
/// A mutable memory location with dynamically checked borrow rules,
/// protected by the Big QEMU Lock.
///
@@ -691,8 +687,6 @@ fn from(t: T) -> BqlRefCell<T> {
}
}
-impl_vmstate_transparent!(crate::cell::BqlRefCell<T> where T: VMState);
-
struct BorrowRef<'b> {
borrow: &'b Cell<BorrowFlag>,
}
diff --git a/rust/meson.build b/rust/meson.build
index 695d5a62de9..7fd857215b0 100644
--- a/rust/meson.build
+++ b/rust/meson.build
@@ -27,8 +27,8 @@ subdir('qemu-macros')
subdir('common')
subdir('bits')
subdir('util')
-subdir('migration')
subdir('bql')
+subdir('migration')
subdir('qom')
subdir('system')
subdir('chardev')
diff --git a/rust/migration/Cargo.toml b/rust/migration/Cargo.toml
index 708bfaaa682..f4a86275152 100644
--- a/rust/migration/Cargo.toml
+++ b/rust/migration/Cargo.toml
@@ -13,6 +13,7 @@ repository.workspace = true
rust-version.workspace = true
[dependencies]
+bql = { path = "../bql" }
common = { path = "../common" }
util = { path = "../util" }
diff --git a/rust/migration/meson.build b/rust/migration/meson.build
index ddf5c2f51d5..e381c76d3e8 100644
--- a/rust/migration/meson.build
+++ b/rust/migration/meson.build
@@ -37,12 +37,12 @@ _migration_rs = static_library(
),
override_options: ['rust_std=2021', 'build.rust_std=2021'],
rust_abi: 'rust',
- link_with: [_util_rs],
+ link_with: [_util_rs, _bql_rs],
dependencies: [common_rs],
)
migration_rs = declare_dependency(link_with: [_migration_rs],
- dependencies: [migration, qemuutil])
+ dependencies: [bql_rs, migration, qemuutil])
# Doctests are essentially integration tests, so they need the same dependencies.
# Note that running them requires the object files for C code, so place them
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index 2900ef1127a..2a29aff7cd6 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -275,6 +275,8 @@ unsafe impl<$base> $crate::vmstate::VMState for $type where $base: $crate::vmsta
};
}
+impl_vmstate_transparent!(bql::BqlCell<T> where T: VMState);
+impl_vmstate_transparent!(bql::BqlRefCell<T> where T: VMState);
impl_vmstate_transparent!(std::cell::Cell<T> where T: VMState);
impl_vmstate_transparent!(std::cell::UnsafeCell<T> where T: VMState);
impl_vmstate_transparent!(std::pin::Pin<T> where T: VMState);
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 06/11] rust: move VMState from bql to migration
2025-10-01 7:52 ` [PATCH 06/11] rust: move VMState from bql to migration Paolo Bonzini
@ 2025-10-13 8:57 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 8:57 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:05AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:05 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 06/11] rust: move VMState from bql to migration
> X-Mailer: git-send-email 2.51.0
>
> The high-level wrapper Migratable<T> will contain a BqlCell,
> which would introduce a circular dependency betwen the bql and
> migration crates. Move the implementation of VMState for cells
> to "migration", together with the implementation for std types.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/Cargo.lock | 4 +---
> rust/bql/Cargo.toml | 3 ---
> rust/bql/meson.build | 1 -
> rust/bql/src/cell.rs | 6 ------
> rust/meson.build | 2 +-
> rust/migration/Cargo.toml | 1 +
> rust/migration/meson.build | 4 ++--
> rust/migration/src/vmstate.rs | 2 ++
> 8 files changed, 7 insertions(+), 16 deletions(-)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 07/11] rust: migration: add high-level migration wrappers
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (5 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 06/11] rust: move VMState from bql to migration Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-14 3:32 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro Paolo Bonzini
` (18 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
Instead of dealing with pre/post callbacks, allow devices to
implement a snapshot/restore mechanism; this has two main
advantages:
- it can be easily implemented via procedural macros
- there can be generic implementations to deal with various
kinds of interior-mutable containers, from BqlRefCell to Mutex,
so that C code does not see Rust concepts such as Mutex<>.
Using it is easy; you can implement the snapshot/restore trait
ToMigrationState and declare your state like:
regs: Migratable<Mutex<MyDeviceRegisters>>
Migratable<> allows dereferencing to the underlying object with
no run-time cost.
Note that Migratable<> actually does not accept ToMigrationState,
only the similar ToMigrationStateShared trait that the user will mostly
not care about. This is required by the fact that pre/post callbacks
take a &self, and ensures that the argument is a Mutex or BqlRefCell
(including an array or Arc<> thereof).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
docs/devel/rust.rst | 1 +
rust/migration/meson.build | 1 +
rust/migration/src/lib.rs | 3 +
rust/migration/src/migratable.rs | 434 +++++++++++++++++++++++++++++++
4 files changed, 439 insertions(+)
create mode 100644 rust/migration/src/migratable.rs
diff --git a/docs/devel/rust.rst b/docs/devel/rust.rst
index 2f0ab2e2821..79c26d9d165 100644
--- a/docs/devel/rust.rst
+++ b/docs/devel/rust.rst
@@ -155,6 +155,7 @@ module status
``hwcore::irq`` complete
``hwcore::qdev`` stable
``hwcore::sysbus`` stable
+``migration::migratable`` proof of concept
``migration::vmstate`` stable
``qom`` stable
``system::memory`` stable
diff --git a/rust/migration/meson.build b/rust/migration/meson.build
index e381c76d3e8..1ba0ec21d72 100644
--- a/rust/migration/meson.build
+++ b/rust/migration/meson.build
@@ -31,6 +31,7 @@ _migration_rs = static_library(
[
'src/lib.rs',
'src/bindings.rs',
+ 'src/migratable.rs',
'src/vmstate.rs',
],
{'.' : _migration_bindings_inc_rs},
diff --git a/rust/migration/src/lib.rs b/rust/migration/src/lib.rs
index 5f51dde4406..efe9896b619 100644
--- a/rust/migration/src/lib.rs
+++ b/rust/migration/src/lib.rs
@@ -2,5 +2,8 @@
pub mod bindings;
+pub mod migratable;
+pub use migratable::*;
+
pub mod vmstate;
pub use vmstate::*;
diff --git a/rust/migration/src/migratable.rs b/rust/migration/src/migratable.rs
new file mode 100644
index 00000000000..46e533c16d1
--- /dev/null
+++ b/rust/migration/src/migratable.rs
@@ -0,0 +1,434 @@
+// Copyright 2025 Red Hat, Inc.
+// Author(s): Paolo Bonzini <pbonzini@redhat.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+use std::{
+ fmt,
+ mem::size_of,
+ ptr::{self, addr_of, NonNull},
+ sync::{Arc, Mutex},
+};
+
+use bql::{BqlCell, BqlRefCell};
+use common::Zeroable;
+
+use crate::{
+ bindings, vmstate_fields_ref, vmstate_of, InvalidError, VMState, VMStateDescriptionBuilder,
+};
+
+/// Enables QEMU migration support even when a type is wrapped with
+/// synchronization primitives (like `Mutex`) that the C migration
+/// code cannot directly handle. The trait provides methods to
+/// extract essential state for migration and restore it after
+/// migration completes.
+///
+/// On top of extracting data from synchronization wrappers during save
+/// and restoring it during load, it's also possible to use `ToMigrationState`
+/// to convert runtime representations to migration-safe formats.
+///
+/// # Examples
+///
+/// ```
+/// use bql::BqlCell;
+/// use migration::{InvalidError, ToMigrationState, VMState};
+/// # use migration::VMStateField;
+///
+/// # #[derive(Debug, PartialEq, Eq)]
+/// struct DeviceState {
+/// counter: BqlCell<u32>,
+/// enabled: bool,
+/// }
+///
+/// # #[derive(Debug)]
+/// #[derive(Default)]
+/// struct DeviceMigrationState {
+/// counter: u32,
+/// enabled: bool,
+/// }
+///
+/// # unsafe impl VMState for DeviceMigrationState {
+/// # const BASE: VMStateField = ::common::Zeroable::ZERO;
+/// # }
+/// impl ToMigrationState for DeviceState {
+/// type Migrated = DeviceMigrationState;
+///
+/// fn snapshot_migration_state(
+/// &self,
+/// target: &mut Self::Migrated,
+/// ) -> Result<(), InvalidError> {
+/// target.counter = self.counter.get();
+/// target.enabled = self.enabled;
+/// Ok(())
+/// }
+///
+/// fn restore_migrated_state_mut(
+/// &mut self,
+/// source: Self::Migrated,
+/// _version_id: u8,
+/// ) -> Result<(), InvalidError> {
+/// self.counter.set(source.counter);
+/// self.enabled = source.enabled;
+/// Ok(())
+/// }
+/// }
+/// # bql::start_test();
+/// # let dev = DeviceState { counter: 10.into(), enabled: true };
+/// # let mig = dev.to_migration_state().unwrap();
+/// # assert!(matches!(*mig, DeviceMigrationState { counter: 10, enabled: true }));
+/// # let mut dev2 = DeviceState { counter: 42.into(), enabled: false };
+/// # dev2.restore_migrated_state_mut(*mig, 1).unwrap();
+/// # assert_eq!(dev2, dev);
+/// ```
+pub trait ToMigrationState {
+ /// The type used to represent the migrated state.
+ type Migrated: Default + VMState;
+
+ /// Capture the current state into a migration-safe format, failing
+ /// if the state cannot be migrated.
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), InvalidError>;
+
+ /// Restores state from a migrated representation, failing if the
+ /// state cannot be restored.
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError>;
+
+ /// Convenience method to combine allocation and state capture
+ /// into a single operation.
+ fn to_migration_state(&self) -> Result<Box<Self::Migrated>, InvalidError> {
+ let mut migrated = Box::<Self::Migrated>::default();
+ self.snapshot_migration_state(&mut migrated)?;
+ Ok(migrated)
+ }
+}
+
+// Implementations for primitive types. Do not use a blanket implementation
+// for all Copy types, because [T; N] is Copy if T is Copy; that would conflict
+// with the below implementation for arrays.
+macro_rules! impl_for_primitive {
+ ($($t:ty),*) => {
+ $(
+ impl ToMigrationState for $t {
+ type Migrated = Self;
+
+ fn snapshot_migration_state(
+ &self,
+ target: &mut Self::Migrated,
+ ) -> Result<(), InvalidError> {
+ *target = *self;
+ Ok(())
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ _version_id: u8,
+ ) -> Result<(), InvalidError> {
+ *self = source;
+ Ok(())
+ }
+ }
+ )*
+ };
+}
+
+impl_for_primitive!(u8, u16, u32, u64, i8, i16, i32, i64, bool);
+
+impl<T: ToMigrationState, const N: usize> ToMigrationState for [T; N]
+where
+ [T::Migrated; N]: Default,
+{
+ type Migrated = [T::Migrated; N];
+
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), InvalidError> {
+ for (item, target_item) in self.iter().zip(target.iter_mut()) {
+ item.snapshot_migration_state(target_item)?;
+ }
+ Ok(())
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ for (item, source_item) in self.iter_mut().zip(source) {
+ item.restore_migrated_state_mut(source_item, version_id)?;
+ }
+ Ok(())
+ }
+}
+
+impl<T: ToMigrationState> ToMigrationState for Mutex<T> {
+ type Migrated = T::Migrated;
+
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), InvalidError> {
+ self.lock().unwrap().snapshot_migration_state(target)
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ self.get_mut()
+ .unwrap()
+ .restore_migrated_state_mut(source, version_id)
+ }
+}
+
+impl<T: ToMigrationState> ToMigrationState for BqlRefCell<T> {
+ type Migrated = T::Migrated;
+
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), InvalidError> {
+ self.borrow().snapshot_migration_state(target)
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ self.get_mut()
+ .restore_migrated_state_mut(source, version_id)
+ }
+}
+
+/// Extension trait for types that support migration state restoration
+/// through interior mutability.
+///
+/// This trait extends [`ToMigrationState`] for types that can restore
+/// their state without requiring mutable access. While user structs
+/// will generally use `ToMigrationState`, the device will have multiple
+/// references and therefore the device struct has to employ an interior
+/// mutability wrapper like [`Mutex`] or [`BqlRefCell`].
+///
+/// Anything that implements this trait can in turn be used within
+/// [`Migratable<T>`], which makes no assumptions on how to achieve mutable
+/// access to the runtime state.
+///
+/// # Examples
+///
+/// ```
+/// use std::sync::Mutex;
+///
+/// use migration::ToMigrationStateShared;
+///
+/// let device_state = Mutex::new(42);
+/// // Can restore without &mut access
+/// device_state.restore_migrated_state(100, 1).unwrap();
+/// assert_eq!(*device_state.lock().unwrap(), 100);
+/// ```
+pub trait ToMigrationStateShared: ToMigrationState {
+ /// Restores state from a migrated representation to an interior-mutable
+ /// object. Similar to `restore_migrated_state_mut`, but requires a
+ /// shared reference; therefore it can be used to restore a device's
+ /// state even though devices have multiple references to them.
+ fn restore_migrated_state(
+ &self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError>;
+}
+
+impl<T: ToMigrationStateShared, const N: usize> ToMigrationStateShared for [T; N]
+where
+ [T::Migrated; N]: Default,
+{
+ fn restore_migrated_state(
+ &self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ for (item, source_item) in self.iter().zip(source) {
+ item.restore_migrated_state(source_item, version_id)?;
+ }
+ Ok(())
+ }
+}
+
+// Arc requires the contained object to be interior-mutable
+impl<T: ToMigrationStateShared> ToMigrationState for Arc<T> {
+ type Migrated = T::Migrated;
+
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), InvalidError> {
+ (**self).snapshot_migration_state(target)
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ (**self).restore_migrated_state(source, version_id)
+ }
+}
+
+impl<T: ToMigrationStateShared> ToMigrationStateShared for Arc<T> {
+ fn restore_migrated_state(
+ &self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ (**self).restore_migrated_state(source, version_id)
+ }
+}
+
+// Interior-mutable types. Note how they only require ToMigrationState for
+// the inner type!
+
+impl<T: ToMigrationState> ToMigrationStateShared for Mutex<T> {
+ fn restore_migrated_state(
+ &self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ self.lock()
+ .unwrap()
+ .restore_migrated_state_mut(source, version_id)
+ }
+}
+
+impl<T: ToMigrationState> ToMigrationStateShared for BqlRefCell<T> {
+ fn restore_migrated_state(
+ &self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ self.borrow_mut()
+ .restore_migrated_state_mut(source, version_id)
+ }
+}
+
+/// A wrapper that enables QEMU migration for types with shared state.
+///
+/// `Migratable<T>` provides a bridge between Rust types that use interior
+/// mutability (like `Mutex<T>`) and QEMU's C-based migration infrastructure.
+/// It manages the lifecycle of migration state and provides automatic
+/// conversion between runtime and migration representations.
+///
+/// ```ignore
+/// # use std::sync::Mutex;
+/// # use migration::Migratable;
+///
+/// pub struct DeviceRegs {
+/// status: u32,
+/// }
+///
+/// pub struct SomeDevice {
+/// // ...
+/// registers: Migratable<Mutex<DeviceRegs>>,
+/// }
+/// ```
+#[repr(C)]
+pub struct Migratable<T: ToMigrationStateShared> {
+ /// Pointer to migration state, valid only during migration operations.
+ /// C vmstate does not support NULL pointers, so no `Option<Box<>>`.
+ migration_state: BqlCell<*mut T::Migrated>,
+
+ /// The runtime state that can be accessed during normal operation
+ runtime_state: T,
+}
+
+impl<T: ToMigrationStateShared> std::ops::Deref for Migratable<T> {
+ type Target = T;
+
+ fn deref(&self) -> &Self::Target {
+ &self.runtime_state
+ }
+}
+
+impl<T: ToMigrationStateShared> std::ops::DerefMut for Migratable<T> {
+ fn deref_mut(&mut self) -> &mut Self::Target {
+ &mut self.runtime_state
+ }
+}
+
+impl<T: ToMigrationStateShared> Migratable<T> {
+ /// Creates a new `Migratable` wrapper around the given runtime state.
+ ///
+ /// # Returns
+ /// A new `Migratable` instance ready for use and migration
+ pub fn new(runtime_state: T) -> Self {
+ Self {
+ migration_state: BqlCell::new(ptr::null_mut()),
+ runtime_state,
+ }
+ }
+
+ fn pre_save(&self) -> Result<(), InvalidError> {
+ let state = self.runtime_state.to_migration_state()?;
+ self.migration_state.set(Box::into_raw(state));
+ Ok(())
+ }
+
+ fn post_save(&self) -> Result<(), InvalidError> {
+ let state = unsafe { Box::from_raw(self.migration_state.replace(ptr::null_mut())) };
+ drop(state);
+ Ok(())
+ }
+
+ fn pre_load(&self) -> Result<(), InvalidError> {
+ self.migration_state
+ .set(Box::into_raw(Box::<T::Migrated>::default()));
+ Ok(())
+ }
+
+ fn post_load(&self, version_id: u8) -> Result<(), InvalidError> {
+ let state = unsafe { Box::from_raw(self.migration_state.replace(ptr::null_mut())) };
+ self.runtime_state
+ .restore_migrated_state(*state, version_id)
+ }
+}
+
+impl<T: ToMigrationStateShared + fmt::Debug> fmt::Debug for Migratable<T>
+where
+ T::Migrated: fmt::Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let mut struct_f = f.debug_struct("Migratable");
+ struct_f.field("runtime_state", &self.runtime_state);
+
+ let state = NonNull::new(self.migration_state.get()).map(|x| unsafe { x.as_ref() });
+ struct_f.field("migration_state", &state);
+ struct_f.finish()
+ }
+}
+
+impl<T: ToMigrationStateShared + Default> Default for Migratable<T> {
+ fn default() -> Self {
+ Self::new(T::default())
+ }
+}
+
+impl<T: 'static + ToMigrationStateShared> Migratable<T> {
+ const FIELD: bindings::VMStateField = vmstate_of!(Self, migration_state);
+
+ const FIELDS: &[bindings::VMStateField] = vmstate_fields_ref! {
+ Migratable::<T>::FIELD
+ };
+
+ const VMSD: &'static bindings::VMStateDescription = VMStateDescriptionBuilder::<Self>::new()
+ .version_id(1)
+ .minimum_version_id(1)
+ .pre_save(&Self::pre_save)
+ .pre_load(&Self::pre_load)
+ .post_save(&Self::post_save)
+ .post_load(&Self::post_load)
+ .fields(Self::FIELDS)
+ .build()
+ .as_ref();
+}
+
+unsafe impl<T: 'static + ToMigrationStateShared> VMState for Migratable<T> {
+ const BASE: bindings::VMStateField = {
+ bindings::VMStateField {
+ vmsd: addr_of!(*Self::VMSD),
+ size: size_of::<Self>(),
+ flags: bindings::VMStateFlags::VMS_STRUCT,
+ ..Zeroable::ZERO
+ }
+ };
+}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 07/11] rust: migration: add high-level migration wrappers
2025-10-01 7:52 ` [PATCH 07/11] rust: migration: add high-level migration wrappers Paolo Bonzini
@ 2025-10-14 3:32 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 3:32 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:06AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:06 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 07/11] rust: migration: add high-level migration wrappers
> X-Mailer: git-send-email 2.51.0
>
> Instead of dealing with pre/post callbacks, allow devices to
> implement a snapshot/restore mechanism; this has two main
> advantages:
>
> - it can be easily implemented via procedural macros
>
> - there can be generic implementations to deal with various
> kinds of interior-mutable containers, from BqlRefCell to Mutex,
> so that C code does not see Rust concepts such as Mutex<>.
>
> Using it is easy; you can implement the snapshot/restore trait
> ToMigrationState and declare your state like:
>
> regs: Migratable<Mutex<MyDeviceRegisters>>
>
> Migratable<> allows dereferencing to the underlying object with
> no run-time cost.
>
> Note that Migratable<> actually does not accept ToMigrationState,
> only the similar ToMigrationStateShared trait that the user will mostly
> not care about. This is required by the fact that pre/post callbacks
> take a &self, and ensures that the argument is a Mutex or BqlRefCell
> (including an array or Arc<> thereof).
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> docs/devel/rust.rst | 1 +
> rust/migration/meson.build | 1 +
> rust/migration/src/lib.rs | 3 +
> rust/migration/src/migratable.rs | 434 +++++++++++++++++++++++++++++++
> 4 files changed, 439 insertions(+)
> create mode 100644 rust/migration/src/migratable.rs
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (6 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 07/11] rust: migration: add high-level migration wrappers Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-14 3:38 ` Zhao Liu
2025-11-03 10:25 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 09/11] timer: constify some functions Paolo Bonzini
` (17 subsequent siblings)
25 siblings, 2 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
Add a macro that recursively builds the "migrated" version
of a struct.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/Cargo.lock | 1 +
rust/migration/Cargo.toml | 1 +
rust/migration/meson.build | 2 +-
rust/migration/src/lib.rs | 2 +
rust/migration/src/migratable.rs | 12 +-
rust/qemu-macros/src/lib.rs | 88 +++++++
rust/qemu-macros/src/migration_state.rs | 296 ++++++++++++++++++++++++
rust/qemu-macros/src/tests.rs | 112 ++++++++-
8 files changed, 509 insertions(+), 5 deletions(-)
create mode 100644 rust/qemu-macros/src/migration_state.rs
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 008d6ca4d62..bf420dce2b8 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -140,6 +140,7 @@ version = "0.1.0"
dependencies = [
"bql",
"common",
+ "qemu_macros",
"util",
]
diff --git a/rust/migration/Cargo.toml b/rust/migration/Cargo.toml
index f4a86275152..8efce7a72cb 100644
--- a/rust/migration/Cargo.toml
+++ b/rust/migration/Cargo.toml
@@ -15,6 +15,7 @@ rust-version.workspace = true
[dependencies]
bql = { path = "../bql" }
common = { path = "../common" }
+qemu_macros = { path = "../qemu-macros" }
util = { path = "../util" }
[lints]
diff --git a/rust/migration/meson.build b/rust/migration/meson.build
index 1ba0ec21d72..362925e320f 100644
--- a/rust/migration/meson.build
+++ b/rust/migration/meson.build
@@ -39,7 +39,7 @@ _migration_rs = static_library(
override_options: ['rust_std=2021', 'build.rust_std=2021'],
rust_abi: 'rust',
link_with: [_util_rs, _bql_rs],
- dependencies: [common_rs],
+ dependencies: [common_rs, qemu_macros],
)
migration_rs = declare_dependency(link_with: [_migration_rs],
diff --git a/rust/migration/src/lib.rs b/rust/migration/src/lib.rs
index efe9896b619..c9bdf0d4133 100644
--- a/rust/migration/src/lib.rs
+++ b/rust/migration/src/lib.rs
@@ -2,6 +2,8 @@
pub mod bindings;
+pub use qemu_macros::ToMigrationState;
+
pub mod migratable;
pub use migratable::*;
diff --git a/rust/migration/src/migratable.rs b/rust/migration/src/migratable.rs
index 46e533c16d1..ded6fe8f4a6 100644
--- a/rust/migration/src/migratable.rs
+++ b/rust/migration/src/migratable.rs
@@ -79,6 +79,10 @@
/// # dev2.restore_migrated_state_mut(*mig, 1).unwrap();
/// # assert_eq!(dev2, dev);
/// ```
+///
+/// More commonly, the trait is derived through the
+/// [`derive(ToMigrationState)`](qemu_macros::ToMigrationState) procedural
+/// macro.
pub trait ToMigrationState {
/// The type used to represent the migrated state.
type Migrated: Default + VMState;
@@ -309,13 +313,17 @@ fn restore_migrated_state(
/// It manages the lifecycle of migration state and provides automatic
/// conversion between runtime and migration representations.
///
-/// ```ignore
+/// ```
/// # use std::sync::Mutex;
-/// # use migration::Migratable;
+/// # use migration::{Migratable, ToMigrationState, VMState, VMStateField};
///
+/// #[derive(ToMigrationState)]
/// pub struct DeviceRegs {
/// status: u32,
/// }
+/// # unsafe impl VMState for DeviceRegsMigration {
+/// # const BASE: VMStateField = ::common::Zeroable::ZERO;
+/// # }
///
/// pub struct SomeDevice {
/// // ...
diff --git a/rust/qemu-macros/src/lib.rs b/rust/qemu-macros/src/lib.rs
index 3e21b67b471..c459f9bcb42 100644
--- a/rust/qemu-macros/src/lib.rs
+++ b/rust/qemu-macros/src/lib.rs
@@ -13,9 +13,13 @@
Attribute, Data, DeriveInput, Error, Field, Fields, FieldsUnnamed, Ident, Meta, Path, Token,
Variant,
};
+
mod bits;
use bits::BitsConstInternal;
+mod migration_state;
+use migration_state::MigrationStateDerive;
+
#[cfg(test)]
mod tests;
@@ -405,3 +409,87 @@ pub fn bits_const_internal(ts: TokenStream) -> TokenStream {
.unwrap_or_else(syn::Error::into_compile_error)
.into()
}
+
+/// Derive macro for generating migration state structures and trait
+/// implementations.
+///
+/// This macro generates a migration state struct and implements the
+/// `ToMigrationState` trait for the annotated struct, enabling state
+/// serialization and restoration. Note that defining a `VMStateDescription`
+/// for the migration state struct is left to the user.
+///
+/// # Container attributes
+///
+/// The following attributes can be applied to the struct:
+///
+/// - `#[migration_state(rename = CustomName)]` - Customizes the name of the
+/// generated migration struct. By default, the generated struct is named
+/// `{OriginalName}Migration`.
+///
+/// # Field attributes
+///
+/// The following attributes can be applied to individual fields:
+///
+/// - `#[migration_state(omit)]` - Excludes the field from the migration state
+/// entirely.
+///
+/// - `#[migration_state(into(Type))]` - Converts the field using `.into()`
+/// during both serialization and restoration.
+///
+/// - `#[migration_state(try_into(Type))]` - Converts the field using
+/// `.try_into()` during both serialization and restoration. Returns
+/// `InvalidError` on conversion failure.
+///
+/// - `#[migration_state(clone)]` - Clones the field value.
+///
+/// Fields without any attributes use `ToMigrationState` recursively; note that
+/// this is a simple copy for types that implement `Copy`.
+///
+/// # Attribute compatibility
+///
+/// - `omit` cannot be used with any other attributes
+/// - only one of `into(Type)`, `try_into(Type)` can be used, but they can be
+/// coupled with `clone`.
+///
+/// # Examples
+///
+/// Basic usage:
+/// ```ignore
+/// #[derive(ToMigrationState)]
+/// struct MyStruct {
+/// field1: u32,
+/// field2: Timer,
+/// }
+/// ```
+///
+/// With attributes:
+/// ```ignore
+/// #[derive(ToMigrationState)]
+/// #[migration_state(rename = CustomMigration)]
+/// struct MyStruct {
+/// #[migration_state(omit)]
+/// runtime_field: u32,
+///
+/// #[migration_state(clone)]
+/// shared_data: String,
+///
+/// #[migration_state(into(Cow<'static, str>), clone)]
+/// converted_field: String,
+///
+/// #[migration_state(try_into(i8))]
+/// fallible_field: u32,
+///
+/// // Default: use ToMigrationState trait recursively
+/// nested_field: NestedStruct,
+///
+/// // Primitive types have a default implementation of ToMigrationState
+/// simple_field: u32,
+/// }
+/// ```
+#[proc_macro_derive(ToMigrationState, attributes(migration_state))]
+pub fn derive_to_migration_state(input: TokenStream) -> TokenStream {
+ let input = parse_macro_input!(input as DeriveInput);
+ MigrationStateDerive::expand(input)
+ .unwrap_or_else(syn::Error::into_compile_error)
+ .into()
+}
diff --git a/rust/qemu-macros/src/migration_state.rs b/rust/qemu-macros/src/migration_state.rs
new file mode 100644
index 00000000000..89feae1e767
--- /dev/null
+++ b/rust/qemu-macros/src/migration_state.rs
@@ -0,0 +1,296 @@
+use std::borrow::Cow;
+
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote, ToTokens};
+use syn::{spanned::Spanned, DeriveInput, Error, Field, Ident, Result, Type};
+
+use crate::get_fields;
+
+#[derive(Debug, Default)]
+enum ConversionMode {
+ #[default]
+ None,
+ Omit,
+ Into(Type),
+ TryInto(Type),
+ ToMigrationState,
+}
+
+impl ConversionMode {
+ fn target_type(&self, original_type: &Type) -> TokenStream {
+ match self {
+ ConversionMode::Into(ty) | ConversionMode::TryInto(ty) => ty.to_token_stream(),
+ ConversionMode::ToMigrationState => {
+ quote! { <#original_type as ToMigrationState>::Migrated }
+ }
+ _ => original_type.to_token_stream(),
+ }
+ }
+}
+
+#[derive(Debug, Default)]
+struct ContainerAttrs {
+ rename: Option<Ident>,
+}
+
+impl ContainerAttrs {
+ fn parse_from(&mut self, attrs: &[syn::Attribute]) -> Result<()> {
+ use attrs::{set, with, Attrs};
+ Attrs::new()
+ .once("rename", with::eq(set::parse(&mut self.rename)))
+ .parse_attrs("migration_state", attrs)?;
+ Ok(())
+ }
+
+ fn parse(attrs: &[syn::Attribute]) -> Result<Self> {
+ let mut container_attrs = Self::default();
+ container_attrs.parse_from(attrs)?;
+ Ok(container_attrs)
+ }
+}
+
+#[derive(Debug, Default)]
+struct FieldAttrs {
+ conversion: ConversionMode,
+ clone: bool,
+}
+
+impl FieldAttrs {
+ fn parse_from(&mut self, attrs: &[syn::Attribute]) -> Result<()> {
+ let mut omit_flag = false;
+ let mut into_type: Option<Type> = None;
+ let mut try_into_type: Option<Type> = None;
+
+ use attrs::{set, with, Attrs};
+ Attrs::new()
+ .once("omit", set::flag(&mut omit_flag))
+ .once("into", with::paren(set::parse(&mut into_type)))
+ .once("try_into", with::paren(set::parse(&mut try_into_type)))
+ .once("clone", set::flag(&mut self.clone))
+ .parse_attrs("migration_state", attrs)?;
+
+ self.conversion = match (omit_flag, into_type, try_into_type, self.clone) {
+ // Valid combinations of attributes first...
+ (true, None, None, false) => ConversionMode::Omit,
+ (false, Some(ty), None, _) => ConversionMode::Into(ty),
+ (false, None, Some(ty), _) => ConversionMode::TryInto(ty),
+ (false, None, None, true) => ConversionMode::None, // clone without conversion
+ (false, None, None, false) => ConversionMode::ToMigrationState, // default behavior
+
+ // ... then the error cases
+ (true, _, _, _) => {
+ return Err(Error::new(
+ attrs[0].span(),
+ "ToMigrationState: omit cannot be used with other attributes",
+ ));
+ }
+ (_, Some(_), Some(_), _) => {
+ return Err(Error::new(
+ attrs[0].span(),
+ "ToMigrationState: into and try_into attributes cannot be used together",
+ ));
+ }
+ };
+
+ Ok(())
+ }
+
+ fn parse(attrs: &[syn::Attribute]) -> Result<Self> {
+ let mut field_attrs = Self::default();
+ field_attrs.parse_from(attrs)?;
+ Ok(field_attrs)
+ }
+}
+
+#[derive(Debug)]
+struct MigrationStateField {
+ name: Ident,
+ original_type: Type,
+ attrs: FieldAttrs,
+}
+
+impl MigrationStateField {
+ fn maybe_clone(&self, mut value: TokenStream) -> TokenStream {
+ if self.attrs.clone {
+ value = quote! { #value.clone() };
+ }
+ value
+ }
+
+ fn generate_migration_state_field(&self) -> TokenStream {
+ let name = &self.name;
+ let field_type = self.attrs.conversion.target_type(&self.original_type);
+
+ quote! {
+ pub #name: #field_type,
+ }
+ }
+
+ fn generate_snapshot_field(&self) -> TokenStream {
+ let name = &self.name;
+ let value = self.maybe_clone(quote! { self.#name });
+
+ match &self.attrs.conversion {
+ ConversionMode::Omit => {
+ unreachable!("Omitted fields are filtered out during processing")
+ }
+ ConversionMode::None => quote! {
+ target.#name = #value;
+ },
+ ConversionMode::Into(_) => quote! {
+ target.#name = #value.into();
+ },
+ ConversionMode::TryInto(_) => quote! {
+ target.#name = #value.try_into().map_err(|_| migration::InvalidError)?;
+ },
+ ConversionMode::ToMigrationState => quote! {
+ self.#name.snapshot_migration_state(&mut target.#name)?;
+ },
+ }
+ }
+
+ fn generate_restore_field(&self) -> TokenStream {
+ let name = &self.name;
+
+ match &self.attrs.conversion {
+ ConversionMode::Omit => {
+ unreachable!("Omitted fields are filtered out during processing")
+ }
+ ConversionMode::None => quote! {
+ self.#name = #name;
+ },
+ ConversionMode::Into(_) => quote! {
+ self.#name = #name.into();
+ },
+ ConversionMode::TryInto(_) => quote! {
+ self.#name = #name.try_into().map_err(|_| migration::InvalidError)?;
+ },
+ ConversionMode::ToMigrationState => quote! {
+ self.#name.restore_migrated_state_mut(#name, version_id)?;
+ },
+ }
+ }
+}
+
+#[derive(Debug)]
+pub struct MigrationStateDerive {
+ input: DeriveInput,
+ fields: Vec<MigrationStateField>,
+ container_attrs: ContainerAttrs,
+}
+
+impl MigrationStateDerive {
+ fn parse(input: DeriveInput) -> Result<Self> {
+ let container_attrs = ContainerAttrs::parse(&input.attrs)?;
+ let fields = get_fields(&input, "ToMigrationState")?;
+ let fields = Self::process_fields(fields)?;
+
+ Ok(Self {
+ input,
+ fields,
+ container_attrs,
+ })
+ }
+
+ fn process_fields(
+ fields: &syn::punctuated::Punctuated<Field, syn::token::Comma>,
+ ) -> Result<Vec<MigrationStateField>> {
+ let processed = fields
+ .iter()
+ .map(|field| {
+ let attrs = FieldAttrs::parse(&field.attrs)?;
+ Ok((field, attrs))
+ })
+ .collect::<Result<Vec<_>>>()?
+ .into_iter()
+ .filter(|(_, attrs)| !matches!(attrs.conversion, ConversionMode::Omit))
+ .map(|(field, attrs)| MigrationStateField {
+ name: field.ident.as_ref().unwrap().clone(),
+ original_type: field.ty.clone(),
+ attrs,
+ })
+ .collect();
+
+ Ok(processed)
+ }
+
+ fn migration_state_name(&self) -> Cow<'_, Ident> {
+ match &self.container_attrs.rename {
+ Some(rename) => Cow::Borrowed(rename),
+ None => Cow::Owned(format_ident!("{}Migration", &self.input.ident)),
+ }
+ }
+
+ fn generate_migration_state_struct(&self) -> TokenStream {
+ let name = self.migration_state_name();
+ let fields = self
+ .fields
+ .iter()
+ .map(MigrationStateField::generate_migration_state_field);
+
+ quote! {
+ #[derive(Default)]
+ pub struct #name {
+ #(#fields)*
+ }
+ }
+ }
+
+ fn generate_snapshot_migration_state(&self) -> TokenStream {
+ let fields = self
+ .fields
+ .iter()
+ .map(MigrationStateField::generate_snapshot_field);
+
+ quote! {
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), migration::InvalidError> {
+ #(#fields)*
+ Ok(())
+ }
+ }
+ }
+
+ fn generate_restore_migrated_state(&self) -> TokenStream {
+ let names: Vec<_> = self.fields.iter().map(|f| &f.name).collect();
+ let fields = self
+ .fields
+ .iter()
+ .map(MigrationStateField::generate_restore_field);
+
+ quote! {
+ fn restore_migrated_state_mut(&mut self, source: Self::Migrated, version_id: u8) -> Result<(), migration::InvalidError> {
+ let Self::Migrated { #(#names),* } = source;
+ #(#fields)*
+ Ok(())
+ }
+ }
+ }
+
+ fn generate(&self) -> TokenStream {
+ let struct_name = &self.input.ident;
+ let generics = &self.input.generics;
+
+ let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+ let name = self.migration_state_name();
+ let migration_state_struct = self.generate_migration_state_struct();
+ let snapshot_impl = self.generate_snapshot_migration_state();
+ let restore_impl = self.generate_restore_migrated_state();
+
+ quote! {
+ #migration_state_struct
+
+ impl #impl_generics ToMigrationState for #struct_name #ty_generics #where_clause {
+ type Migrated = #name;
+
+ #snapshot_impl
+
+ #restore_impl
+ }
+ }
+ }
+
+ pub fn expand(input: DeriveInput) -> Result<TokenStream> {
+ let tokens = Self::parse(input)?.generate();
+ Ok(tokens)
+ }
+}
diff --git a/rust/qemu-macros/src/tests.rs b/rust/qemu-macros/src/tests.rs
index ac998d20e30..7516bc3d92a 100644
--- a/rust/qemu-macros/src/tests.rs
+++ b/rust/qemu-macros/src/tests.rs
@@ -7,7 +7,7 @@
use super::*;
macro_rules! derive_compile_fail {
- ($derive_fn:ident, $input:expr, $($error_msg:expr),+ $(,)?) => {{
+ ($derive_fn:path, $input:expr, $($error_msg:expr),+ $(,)?) => {{
let input: proc_macro2::TokenStream = $input;
let error_msg = &[$( quote! { ::core::compile_error! { $error_msg } } ),*];
let derive_fn: fn(input: syn::DeriveInput) -> Result<proc_macro2::TokenStream, syn::Error> =
@@ -24,7 +24,7 @@ macro_rules! derive_compile_fail {
}
macro_rules! derive_compile {
- ($derive_fn:ident, $input:expr, $($expected:tt)*) => {{
+ ($derive_fn:path, $input:expr, $($expected:tt)*) => {{
let input: proc_macro2::TokenStream = $input;
let expected: proc_macro2::TokenStream = $($expected)*;
let derive_fn: fn(input: syn::DeriveInput) -> Result<proc_macro2::TokenStream, syn::Error> =
@@ -345,3 +345,111 @@ fn try_from(value: u8) -> Result<Self, u8> {
}
);
}
+
+#[test]
+fn test_derive_to_migration_state() {
+ derive_compile_fail!(
+ MigrationStateDerive::expand,
+ quote! {
+ struct MyStruct {
+ #[migration_state(omit, clone)]
+ bad: u32,
+ }
+ },
+ "ToMigrationState: omit cannot be used with other attributes"
+ );
+ derive_compile_fail!(
+ MigrationStateDerive::expand,
+ quote! {
+ struct MyStruct {
+ #[migration_state(into)]
+ bad: u32,
+ }
+ },
+ "unexpected end of input, expected parentheses"
+ );
+ derive_compile_fail!(
+ MigrationStateDerive::expand,
+ quote! {
+ struct MyStruct {
+ #[migration_state(into(String), try_into(String))]
+ bad: &'static str,
+ }
+ },
+ "ToMigrationState: into and try_into attributes cannot be used together"
+ );
+ derive_compile!(
+ MigrationStateDerive::expand,
+ quote! {
+ #[migration_state(rename = CustomMigration)]
+ struct MyStruct {
+ #[migration_state(omit)]
+ runtime_field: u32,
+
+ #[migration_state(clone)]
+ shared_data: String,
+
+ #[migration_state(into(Cow<'static, str>), clone)]
+ converted_field: String,
+
+ #[migration_state(try_into(i8))]
+ fallible_field: u32,
+
+ nested_field: NestedStruct,
+ simple_field: u32,
+ }
+ },
+ quote! {
+ #[derive(Default)]
+ pub struct CustomMigration {
+ pub shared_data: String,
+ pub converted_field: Cow<'static, str>,
+ pub fallible_field: i8,
+ pub nested_field: <NestedStruct as ToMigrationState>::Migrated,
+ pub simple_field: <u32 as ToMigrationState>::Migrated,
+ }
+ impl ToMigrationState for MyStruct {
+ type Migrated = CustomMigration;
+ fn snapshot_migration_state(
+ &self,
+ target: &mut Self::Migrated
+ ) -> Result<(), migration::InvalidError> {
+ target.shared_data = self.shared_data.clone();
+ target.converted_field = self.converted_field.clone().into();
+ target.fallible_field = self
+ .fallible_field
+ .try_into()
+ .map_err(|_| migration::InvalidError)?;
+ self.nested_field
+ .snapshot_migration_state(&mut target.nested_field)?;
+ self.simple_field
+ .snapshot_migration_state(&mut target.simple_field)?;
+ Ok(())
+ }
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8
+ ) -> Result<(), migration::InvalidError> {
+ let Self::Migrated {
+ shared_data,
+ converted_field,
+ fallible_field,
+ nested_field,
+ simple_field
+ } = source;
+ self.shared_data = shared_data;
+ self.converted_field = converted_field.into();
+ self.fallible_field = fallible_field
+ .try_into()
+ .map_err(|_| migration::InvalidError)?;
+ self.nested_field
+ .restore_migrated_state_mut(nested_field, version_id)?;
+ self.simple_field
+ .restore_migrated_state_mut(simple_field, version_id)?;
+ Ok(())
+ }
+ }
+ }
+ );
+}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
2025-10-01 7:52 ` [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro Paolo Bonzini
@ 2025-10-14 3:38 ` Zhao Liu
2025-11-03 10:25 ` Zhao Liu
1 sibling, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 3:38 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:07AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:07 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
> X-Mailer: git-send-email 2.51.0
>
> Add a macro that recursively builds the "migrated" version
> of a struct.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/Cargo.lock | 1 +
> rust/migration/Cargo.toml | 1 +
> rust/migration/meson.build | 2 +-
> rust/migration/src/lib.rs | 2 +
> rust/migration/src/migratable.rs | 12 +-
> rust/qemu-macros/src/lib.rs | 88 +++++++
> rust/qemu-macros/src/migration_state.rs | 296 ++++++++++++++++++++++++
> rust/qemu-macros/src/tests.rs | 112 ++++++++-
> 8 files changed, 509 insertions(+), 5 deletions(-)
> create mode 100644 rust/qemu-macros/src/migration_state.rs
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* Re: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
2025-10-01 7:52 ` [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro Paolo Bonzini
2025-10-14 3:38 ` Zhao Liu
@ 2025-11-03 10:25 ` Zhao Liu
2025-11-03 15:49 ` Zhao Liu
1 sibling, 1 reply; 55+ messages in thread
From: Zhao Liu @ 2025-11-03 10:25 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust
Hi Paolo,
> /// # use std::sync::Mutex;
> -/// # use migration::Migratable;
> +/// # use migration::{Migratable, ToMigrationState, VMState, VMStateField};
> ///
> +/// #[derive(ToMigrationState)]
> /// pub struct DeviceRegs {
> /// status: u32,
> /// }
> +/// # unsafe impl VMState for DeviceRegsMigration {
> +/// # const BASE: VMStateField = ::common::Zeroable::ZERO;
> +/// # }
did you miss something like the following?
diff --git a/rust/qemu-macros/src/migration_state.rs b/rust/qemu-macros/src/migration_state.rs
index 5edf0efe687f..2064bb73a6f0 100644
--- a/rust/qemu-macros/src/migration_state.rs
+++ b/rust/qemu-macros/src/migration_state.rs
@@ -236,6 +236,16 @@ pub struct #name {
}
}
+ fn generate_vmstate_impl(&self) -> TokenStream {
+ let name = self.migration_state_name();
+
+ quote! {
+ unsafe impl ::migration::VMState for #name {
+ const BASE: ::migration::VMStateField = ::common::Zeroable::ZERO;
+ }
+ }
+ }
+
fn generate_snapshot_migration_state(&self) -> TokenStream {
let fields = self
.fields
@@ -275,12 +285,15 @@ fn generate(&self) -> TokenStream {
let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
let name = self.migration_state_name();
let migration_state_struct = self.generate_migration_state_struct();
+ let vmstate_impl = self.generate_vmstate_impl();
let snapshot_impl = self.generate_snapshot_migration_state();
let restore_impl = self.generate_restore_migrated_state();
quote! {
#migration_state_struct
+ #vmstate_impl
+
impl #impl_generics ToMigrationState for #struct_name #ty_generics #where_clause {
type Migrated = #name;
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
2025-11-03 10:25 ` Zhao Liu
@ 2025-11-03 15:49 ` Zhao Liu
2025-11-04 14:40 ` Paolo Bonzini
2025-11-04 14:41 ` Zhao Liu
0 siblings, 2 replies; 55+ messages in thread
From: Zhao Liu @ 2025-11-03 15:49 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust
On Mon, Nov 03, 2025 at 06:25:26PM +0800, Zhao Liu wrote:
> Date: Mon, 3 Nov 2025 18:25:26 +0800
> From: Zhao Liu <zhao1.liu@intel.com>
> Subject: Re: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive
> macro
>
> Hi Paolo,
>
> > /// # use std::sync::Mutex;
> > -/// # use migration::Migratable;
> > +/// # use migration::{Migratable, ToMigrationState, VMState, VMStateField};
> > ///
> > +/// #[derive(ToMigrationState)]
> > /// pub struct DeviceRegs {
> > /// status: u32,
> > /// }
> > +/// # unsafe impl VMState for DeviceRegsMigration {
> > +/// # const BASE: VMStateField = ::common::Zeroable::ZERO;
> > +/// # }
>
> did you miss something like the following?
>
>
> diff --git a/rust/qemu-macros/src/migration_state.rs b/rust/qemu-macros/src/migration_state.rs
> index 5edf0efe687f..2064bb73a6f0 100644
> --- a/rust/qemu-macros/src/migration_state.rs
> +++ b/rust/qemu-macros/src/migration_state.rs
> @@ -236,6 +236,16 @@ pub struct #name {
> }
> }
>
> + fn generate_vmstate_impl(&self) -> TokenStream {
> + let name = self.migration_state_name();
> +
> + quote! {
> + unsafe impl ::migration::VMState for #name {
> + const BASE: ::migration::VMStateField = ::common::Zeroable::ZERO;
It seems the generated migration_state_struct needs a complete VMSD:
collect all its fields and build a VMSD.
And then apply impl_vmstate_struct! to this migration_state_struct.
If we zero the BASE, then `vmstate_of!(Self, migration_state)` seems
can't migrate its fields.
Thanks,
Zhao
^ permalink raw reply [flat|nested] 55+ messages in thread* Re: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
2025-11-03 15:49 ` Zhao Liu
@ 2025-11-04 14:40 ` Paolo Bonzini
2025-11-04 14:41 ` Zhao Liu
1 sibling, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-11-04 14:40 UTC (permalink / raw)
To: Zhao Liu; +Cc: qemu-devel, qemu-rust
On 11/3/25 16:49, Zhao Liu wrote:
>> did you miss something like the following?
>>
>>
>> diff --git a/rust/qemu-macros/src/migration_state.rs b/rust/qemu-macros/src/migration_state.rs
>> index 5edf0efe687f..2064bb73a6f0 100644
>> --- a/rust/qemu-macros/src/migration_state.rs
>> +++ b/rust/qemu-macros/src/migration_state.rs
>> @@ -236,6 +236,16 @@ pub struct #name {
>> }
>> }
>>
>> + fn generate_vmstate_impl(&self) -> TokenStream {
>> + let name = self.migration_state_name();
>> +
>> + quote! {
>> + unsafe impl ::migration::VMState for #name {
>> + const BASE: ::migration::VMStateField = ::common::Zeroable::ZERO;
>
> It seems the generated migration_state_struct needs a complete VMSD:
> collect all its fields and build a VMSD.
>
> And then apply impl_vmstate_struct! to this migration_state_struct.
>
> If we zero the BASE, then `vmstate_of!(Self, migration_state)` seems
> can't migrate its fields.
The VMStateDescription for the inner struct is indeed missing, but you
need to write it yourself and apply impl_vmstate_struct, because the
derive macro cannot know the checks or version_ids for each field, or
the subsections.
The VMStateDescription for Migratable<> however is automatic (of
course), and the outer VMStateDescription for the device is simple---it
consists only of the parent class if applicable, and the Migratable<>,
similar to VMSTATE_PL011.
For HPET, you'll have to move the subsections from VMSTATE_HPET to the
inner VMState.
Paolo
^ permalink raw reply [flat|nested] 55+ messages in thread* Re: [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro
2025-11-03 15:49 ` Zhao Liu
2025-11-04 14:40 ` Paolo Bonzini
@ 2025-11-04 14:41 ` Zhao Liu
1 sibling, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-11-04 14:41 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust
> It seems the generated migration_state_struct needs a complete VMSD:
> collect all its fields and build a VMSD.
>
> And then apply impl_vmstate_struct! to this migration_state_struct.
>
> If we zero the BASE, then `vmstate_of!(Self, migration_state)` seems
> can't migrate its fields.
I think the following generated vmstate implementation should be what we
need:
diff --git a/rust/qemu-macros/src/migration_state.rs b/rust/qemu-macros/src/migration_state.rs
index 5edf0efe687f..cb047638e3da 100644
--- a/rust/qemu-macros/src/migration_state.rs
+++ b/rust/qemu-macros/src/migration_state.rs
@@ -1,6 +1,6 @@
use std::borrow::Cow;
-use proc_macro2::TokenStream;
+use proc_macro2::{Literal, TokenStream};
use quote::{format_ident, quote, ToTokens};
use syn::{spanned::Spanned, DeriveInput, Error, Field, Ident, Result, Type};
@@ -236,6 +236,43 @@ pub struct #name {
}
}
+ fn generate_vmstate_impl(&self) -> TokenStream {
+ let name = self.migration_state_name();
+ let name_str = name.to_string();
+ // Most of the time, const variables use uppercase snake case style,
+ // while VMStateDescription.name uses lowercase snake case. But we're
+ // not strictly following the usual snake case conventions here because
+ // what we have is good enough for the generated code right now.
+ //
+ // QEMU struct names are typically in camel case, but there are exceptions
+ // - like non-standard camel case such as HPETState. So converting from
+ // camel to snake case would need an extra helper.
+ let vmsd_name = format_ident!("VMSTATE_{}", name_str);
+ // C-string literal "c" can't be used in quote! directly.
+ let vmsd_c_name = Literal::c_string(&std::ffi::CString::new(name_str).unwrap());
+
+ let vmstate_fields = self.fields.iter().map(|field| {
+ let field_name = &field.name;
+ quote! {
+ vmstate_of!(#name, #field_name),
+ }
+ });
+
+ quote! {
+ const #vmsd_name: VMStateDescription<#name> =
+ VMStateDescriptionBuilder::<#name>::new()
+ .name(#vmsd_c_name)
+ .version_id(0)
+ .minimum_version_id(0)
+ .fields(vmstate_fields! {
+ #(#vmstate_fields)*
+ })
+ .build();
+
+ impl_vmstate_struct!(#name, #vmsd_name);
+ }
+ }
+
fn generate_snapshot_migration_state(&self) -> TokenStream {
let fields = self
.fields
@@ -275,12 +312,15 @@ fn generate(&self) -> TokenStream {
let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
let name = self.migration_state_name();
let migration_state_struct = self.generate_migration_state_struct();
+ let vmstate_impl = self.generate_vmstate_impl();
let snapshot_impl = self.generate_snapshot_migration_state();
let restore_impl = self.generate_restore_migrated_state();
quote! {
#migration_state_struct
+ #vmstate_impl
+
impl #impl_generics ToMigrationState for #struct_name #ty_generics #where_clause {
type Migrated = #name;
diff --git a/rust/qemu-macros/src/tests.rs b/rust/qemu-macros/src/tests.rs
index 65691412ff57..d70ebf23c273 100644
--- a/rust/qemu-macros/src/tests.rs
+++ b/rust/qemu-macros/src/tests.rs
@@ -408,6 +408,20 @@ pub struct CustomMigration {
pub nested_field: <NestedStruct as ToMigrationState>::Migrated,
pub simple_field: <u32 as ToMigrationState>::Migrated,
}
+ const VMSTATE_CustomMigration: VMStateDescription <CustomMigration> =
+ VMStateDescriptionBuilder::<CustomMigration>::new()
+ .name(c"CustomMigration")
+ .version_id(0)
+ .minimum_version_id(0)
+ .fields(vmstate_fields! {
+ vmstate_of!(CustomMigration, shared_data),
+ vmstate_of!(CustomMigration, converted_field),
+ vmstate_of!(CustomMigration, fallible_field),
+ vmstate_of!(CustomMigration, nested_field),
+ vmstate_of!(CustomMigration, simple_field),
+ })
+ .build();
+ impl_vmstate_struct!(CustomMigration, VMSTATE_CustomMigration);
impl ToMigrationState for MyStruct {
type Migrated = CustomMigration;
fn snapshot_migration_state(
^ permalink raw reply related [flat|nested] 55+ messages in thread
* [PATCH 09/11] timer: constify some functions
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (7 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 08/11] rust: qemu-macros: add ToMigrationState derive macro Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-14 3:38 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 10/11] rust: migration: implement ToMigrationState for Timer Paolo Bonzini
` (16 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/qemu/timer.h | 6 +++---
util/qemu-timer.c | 8 ++++----
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index abd2204f3be..aec730ac257 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -699,7 +699,7 @@ void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time);
*
* Returns: true if the timer is pending
*/
-bool timer_pending(QEMUTimer *ts);
+bool timer_pending(const QEMUTimer *ts);
/**
* timer_expired:
@@ -710,7 +710,7 @@ bool timer_pending(QEMUTimer *ts);
*
* Returns: true if the timer has expired
*/
-bool timer_expired(QEMUTimer *timer_head, int64_t current_time);
+bool timer_expired(const QEMUTimer *timer_head, int64_t current_time);
/**
* timer_expire_time_ns:
@@ -720,7 +720,7 @@ bool timer_expired(QEMUTimer *timer_head, int64_t current_time);
*
* Returns: the expiry time in nanoseconds
*/
-uint64_t timer_expire_time_ns(QEMUTimer *ts);
+uint64_t timer_expire_time_ns(const QEMUTimer *ts);
/**
* timer_get:
diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index 1fb48be281a..56f11b6a641 100644
--- a/util/qemu-timer.c
+++ b/util/qemu-timer.c
@@ -89,7 +89,7 @@ static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
return &qemu_clocks[type];
}
-static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
+static bool timer_expired_ns(const QEMUTimer *timer_head, int64_t current_time)
{
return timer_head && (timer_head->expire_time <= current_time);
}
@@ -475,12 +475,12 @@ void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
timer_mod_anticipate_ns(ts, expire_time * ts->scale);
}
-bool timer_pending(QEMUTimer *ts)
+bool timer_pending(const QEMUTimer *ts)
{
return ts->expire_time >= 0;
}
-bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
+bool timer_expired(const QEMUTimer *timer_head, int64_t current_time)
{
return timer_expired_ns(timer_head, current_time * timer_head->scale);
}
@@ -649,7 +649,7 @@ void init_clocks(QEMUTimerListNotifyCB *notify_cb)
#endif
}
-uint64_t timer_expire_time_ns(QEMUTimer *ts)
+uint64_t timer_expire_time_ns(const QEMUTimer *ts)
{
return timer_pending(ts) ? ts->expire_time : -1;
}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 09/11] timer: constify some functions
2025-10-01 7:52 ` [PATCH 09/11] timer: constify some functions Paolo Bonzini
@ 2025-10-14 3:38 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 3:38 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:08AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:08 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 09/11] timer: constify some functions
> X-Mailer: git-send-email 2.51.0
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> include/qemu/timer.h | 6 +++---
> util/qemu-timer.c | 8 ++++----
> 2 files changed, 7 insertions(+), 7 deletions(-)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 10/11] rust: migration: implement ToMigrationState for Timer
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (8 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 09/11] timer: constify some functions Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-14 6:55 ` Zhao Liu
2025-10-01 7:52 ` [PATCH 11/11] rust: migration: implement ToMigrationState as part of impl_vmstate_bitsized Paolo Bonzini
` (15 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
Timer is a complex struct, allow adding it to a struct that
uses #[derive(ToMigrationState)]; similar to vmstate_timer, only
the expiration time has to be preserved.
In fact, because it is thread-safe, ToMigrationStateShared can
also be implemented without needing a cell or mutex that wraps
the timer.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/migration/src/migratable.rs | 31 +++++++++++++++++++++++++++++++
rust/util/src/timer.rs | 10 +++++++++-
2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/rust/migration/src/migratable.rs b/rust/migration/src/migratable.rs
index ded6fe8f4a6..e85ef810efc 100644
--- a/rust/migration/src/migratable.rs
+++ b/rust/migration/src/migratable.rs
@@ -140,6 +140,26 @@ fn restore_migrated_state_mut(
impl_for_primitive!(u8, u16, u32, u64, i8, i16, i32, i64, bool);
+impl ToMigrationState for util::timer::Timer {
+ type Migrated = i64;
+
+ fn snapshot_migration_state(&self, target: &mut i64) -> Result<(), InvalidError> {
+ // SAFETY: as_ptr() is unsafe to ensure that the caller reasons about
+ // the pinning of the data inside the Opaque<>. Here all we do is
+ // access a field.
+ *target = self.expire_time_ns().unwrap_or(-1);
+ Ok(())
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), InvalidError> {
+ self.restore_migrated_state(source, version_id)
+ }
+}
+
impl<T: ToMigrationState, const N: usize> ToMigrationState for [T; N]
where
[T::Migrated; N]: Default,
@@ -237,6 +257,17 @@ fn restore_migrated_state(
) -> Result<(), InvalidError>;
}
+impl ToMigrationStateShared for util::timer::Timer {
+ fn restore_migrated_state(&self, source: i64, _version_id: u8) -> Result<(), InvalidError> {
+ if source >= 0 {
+ self.modify(source as u64);
+ } else {
+ self.delete();
+ }
+ Ok(())
+ }
+}
+
impl<T: ToMigrationStateShared, const N: usize> ToMigrationStateShared for [T; N]
where
[T::Migrated; N]: Default,
diff --git a/rust/util/src/timer.rs b/rust/util/src/timer.rs
index c6b3e4088ec..a99ff5e7ef7 100644
--- a/rust/util/src/timer.rs
+++ b/rust/util/src/timer.rs
@@ -10,7 +10,8 @@
use common::{callbacks::FnCall, Opaque};
use crate::bindings::{
- self, qemu_clock_get_ns, timer_del, timer_init_full, timer_mod, QEMUClockType,
+ self, qemu_clock_get_ns, timer_del, timer_expire_time_ns, timer_init_full, timer_mod,
+ QEMUClockType,
};
/// A safe wrapper around [`bindings::QEMUTimer`].
@@ -86,6 +87,13 @@ pub fn init_full<'timer, 'opaque: 'timer, T, F>(
}
}
+ pub fn expire_time_ns(&self) -> Option<i64> {
+ // SAFETY: the only way to obtain a Timer safely is via methods that
+ // take a Pin<&mut Self>, therefore the timer is pinned
+ let ret = unsafe { timer_expire_time_ns(self.as_ptr()) };
+ i64::try_from(ret).ok()
+ }
+
pub fn modify(&self, expire_time: u64) {
// SAFETY: the only way to obtain a Timer safely is via methods that
// take a Pin<&mut Self>, therefore the timer is pinned
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 10/11] rust: migration: implement ToMigrationState for Timer
2025-10-01 7:52 ` [PATCH 10/11] rust: migration: implement ToMigrationState for Timer Paolo Bonzini
@ 2025-10-14 6:55 ` Zhao Liu
2025-10-14 7:26 ` [PATCH 1/2] rust/timer: Make Timer::modify() accept an i64 expire_time Timer Zhao Liu
` (2 more replies)
0 siblings, 3 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 6:55 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, Zhao Liu
On Wed, Oct 01, 2025 at 09:52:09AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:09 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 10/11] rust: migration: implement ToMigrationState for Timer
> X-Mailer: git-send-email 2.51.0
>
> Timer is a complex struct, allow adding it to a struct that
> uses #[derive(ToMigrationState)]; similar to vmstate_timer, only
> the expiration time has to be preserved.
>
> In fact, because it is thread-safe, ToMigrationStateShared can
> also be implemented without needing a cell or mutex that wraps
> the timer.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/migration/src/migratable.rs | 31 +++++++++++++++++++++++++++++++
> rust/util/src/timer.rs | 10 +++++++++-
> 2 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/rust/migration/src/migratable.rs b/rust/migration/src/migratable.rs
> index ded6fe8f4a6..e85ef810efc 100644
> --- a/rust/migration/src/migratable.rs
> +++ b/rust/migration/src/migratable.rs
> @@ -140,6 +140,26 @@ fn restore_migrated_state_mut(
>
> impl_for_primitive!(u8, u16, u32, u64, i8, i16, i32, i64, bool);
>
> +impl ToMigrationState for util::timer::Timer {
> + type Migrated = i64;
> +
> + fn snapshot_migration_state(&self, target: &mut i64) -> Result<(), InvalidError> {
> + // SAFETY: as_ptr() is unsafe to ensure that the caller reasons about
> + // the pinning of the data inside the Opaque<>. Here all we do is
> + // access a field.
> + *target = self.expire_time_ns().unwrap_or(-1);
> + Ok(())
> + }
> +
> + fn restore_migrated_state_mut(
> + &mut self,
> + source: Self::Migrated,
> + version_id: u8,
> + ) -> Result<(), InvalidError> {
> + self.restore_migrated_state(source, version_id)
> + }
> +}
> +
> impl<T: ToMigrationState, const N: usize> ToMigrationState for [T; N]
> where
> [T::Migrated; N]: Default,
> @@ -237,6 +257,17 @@ fn restore_migrated_state(
> ) -> Result<(), InvalidError>;
> }
>
> +impl ToMigrationStateShared for util::timer::Timer {
> + fn restore_migrated_state(&self, source: i64, _version_id: u8) -> Result<(), InvalidError> {
> + if source >= 0 {
> + self.modify(source as u64);
Timer::modify() is the wrapper of timer_mod(), and timer_mod() will
re-compute the expire time with scale factor.
So here we should use a binding of timer_mod_ns() - Timer::modify_ns()
instead of Timer::modify(), just like C side did.
Moreover, for Timer::modify_ns() & Timer::modify(), the simplest
way is to build them based on timer_mod_ns() & timer_mod() (but this
sounds like shifting the responsibility for type checking and overflow
checking to the C side :-( ).
Alternative, we can make Timer::modify() based on Timer::modify_ns(),
but then it involves many numeric type conversions: scale is i32 but
expire_time is u64, and Timer::modify_ns() may accept a u64 argument.
Fortunately,, we can make Timer's modify() accept i64 to reduce type
conversions.
> + } else {
> + self.delete();
> + }
> + Ok(())
> + }
> +}
> +
> impl<T: ToMigrationStateShared, const N: usize> ToMigrationStateShared for [T; N]
> where
> [T::Migrated; N]: Default,
> diff --git a/rust/util/src/timer.rs b/rust/util/src/timer.rs
> index c6b3e4088ec..a99ff5e7ef7 100644
> --- a/rust/util/src/timer.rs
> +++ b/rust/util/src/timer.rs
> @@ -10,7 +10,8 @@
> use common::{callbacks::FnCall, Opaque};
>
> use crate::bindings::{
> - self, qemu_clock_get_ns, timer_del, timer_init_full, timer_mod, QEMUClockType,
> + self, qemu_clock_get_ns, timer_del, timer_expire_time_ns, timer_init_full, timer_mod,
> + QEMUClockType,
> };
>
> /// A safe wrapper around [`bindings::QEMUTimer`].
> @@ -86,6 +87,13 @@ pub fn init_full<'timer, 'opaque: 'timer, T, F>(
> }
> }
>
> + pub fn expire_time_ns(&self) -> Option<i64> {
> + // SAFETY: the only way to obtain a Timer safely is via methods that
> + // take a Pin<&mut Self>, therefore the timer is pinned
> + let ret = unsafe { timer_expire_time_ns(self.as_ptr()) };
> + i64::try_from(ret).ok()
Good! This detects all negative values.
> + }
> +
> pub fn modify(&self, expire_time: u64) {
> // SAFETY: the only way to obtain a Timer safely is via methods that
> // take a Pin<&mut Self>, therefore the timer is pinned
> --
> 2.51.0
>
^ permalink raw reply [flat|nested] 55+ messages in thread* [PATCH 1/2] rust/timer: Make Timer::modify() accept an i64 expire_time Timer
2025-10-14 6:55 ` Zhao Liu
@ 2025-10-14 7:26 ` Zhao Liu
2025-10-14 7:28 ` [PATCH 2/2] rust/timer: Add Timer::modify_ns() Zhao Liu
2025-10-14 13:56 ` [PATCH 10/11] rust: migration: implement ToMigrationState for Timer Paolo Bonzini
2 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 7:26 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, Zhao Liu
At C side, timer_mod() accepts the int64_t expire_time as an argument.
In fact, int64_t defines the positive value range accepted by
expire_timer is (0, INT64_MAX].
But at Rust side, Timer::modify() accepts an u64 expire_time and convert
it to i64 internally. This is a lazy approach, assuming no one would use
negative values to modify the timer. However, logically speaking, a
negative expire_time is acceptable - it means that the current timer
should fire immediately.
Moreover, specifying expire_time as i64 allows callers to more clearly
understand the accepted value range, preventing them from unexpectedly
finding a `u64` (> `i64::MAX`) silently converted to a negative value.
Make Timer::modify() accept an i64 expire_time.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
rust/hw/timer/hpet/src/device.rs | 2 +-
rust/util/src/timer.rs | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/rust/hw/timer/hpet/src/device.rs b/rust/hw/timer/hpet/src/device.rs
index 86638c076666..f0ac01758e72 100644
--- a/rust/hw/timer/hpet/src/device.rs
+++ b/rust/hw/timer/hpet/src/device.rs
@@ -365,7 +365,7 @@ fn arm_timer(&mut self, tick: u64) {
}
self.last = ns;
- self.qemu_timer.modify(self.last);
+ self.qemu_timer.modify(self.last.try_into().unwrap());
}
fn set_timer(&mut self) {
diff --git a/rust/util/src/timer.rs b/rust/util/src/timer.rs
index c6b3e4088ecb..c3a9de6b72df 100644
--- a/rust/util/src/timer.rs
+++ b/rust/util/src/timer.rs
@@ -86,10 +86,10 @@ pub fn init_full<'timer, 'opaque: 'timer, T, F>(
}
}
- pub fn modify(&self, expire_time: u64) {
+ pub fn modify(&self, expire_time: i64) {
// SAFETY: the only way to obtain a Timer safely is via methods that
// take a Pin<&mut Self>, therefore the timer is pinned
- unsafe { timer_mod(self.as_mut_ptr(), expire_time as i64) }
+ unsafe { timer_mod(self.as_mut_ptr(), expire_time) }
}
pub fn delete(&self) {
--
2.34.1
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 2/2] rust/timer: Add Timer::modify_ns()
2025-10-14 6:55 ` Zhao Liu
2025-10-14 7:26 ` [PATCH 1/2] rust/timer: Make Timer::modify() accept an i64 expire_time Timer Zhao Liu
@ 2025-10-14 7:28 ` Zhao Liu
2025-10-14 13:56 ` [PATCH 10/11] rust: migration: implement ToMigrationState for Timer Paolo Bonzini
2 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 7:28 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, Zhao Liu
Add the binding of timer_mod_ns(), and re-implement Timer::modify()
based on Timer::modify_ns().
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
rust/util/src/timer.rs | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/rust/util/src/timer.rs b/rust/util/src/timer.rs
index c3a9de6b72df..88f120c54185 100644
--- a/rust/util/src/timer.rs
+++ b/rust/util/src/timer.rs
@@ -10,7 +10,7 @@
use common::{callbacks::FnCall, Opaque};
use crate::bindings::{
- self, qemu_clock_get_ns, timer_del, timer_init_full, timer_mod, QEMUClockType,
+ self, qemu_clock_get_ns, timer_del, timer_init_full, timer_mod_ns, QEMUClockType,
};
/// A safe wrapper around [`bindings::QEMUTimer`].
@@ -86,10 +86,18 @@ pub fn init_full<'timer, 'opaque: 'timer, T, F>(
}
}
- pub fn modify(&self, expire_time: i64) {
+ pub fn modify_ns(&self, expire_time: i64) {
// SAFETY: the only way to obtain a Timer safely is via methods that
// take a Pin<&mut Self>, therefore the timer is pinned
- unsafe { timer_mod(self.as_mut_ptr(), expire_time) }
+ unsafe { timer_mod_ns(self.as_mut_ptr(), expire_time) }
+ }
+
+ pub fn modify(&self, expire_time: i64) {
+ // SAFETY: the only way to obtain a Timer safely is via methods that
+ // take a Pin<&mut Self>, therefore the timer is pinned and is valid
+ let scale = unsafe { *self.as_ptr() }.scale as i64;
+ // Following C's behavior, scale expire_time even when it is negative.
+ self.modify_ns(expire_time * scale);
}
pub fn delete(&self) {
--
2.34.1
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 10/11] rust: migration: implement ToMigrationState for Timer
2025-10-14 6:55 ` Zhao Liu
2025-10-14 7:26 ` [PATCH 1/2] rust/timer: Make Timer::modify() accept an i64 expire_time Timer Zhao Liu
2025-10-14 7:28 ` [PATCH 2/2] rust/timer: Add Timer::modify_ns() Zhao Liu
@ 2025-10-14 13:56 ` Paolo Bonzini
2 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-14 13:56 UTC (permalink / raw)
To: Zhao Liu; +Cc: qemu-devel
On Tue, Oct 14, 2025 at 8:33 AM Zhao Liu <zhao1.liu@intel.com> wrote:
> > +impl ToMigrationStateShared for util::timer::Timer {
> > + fn restore_migrated_state(&self, source: i64, _version_id: u8) -> Result<(), InvalidError> {
> > + if source >= 0 {
> > + self.modify(source as u64);
>
> Timer::modify() is the wrapper of timer_mod(), and timer_mod() will
> re-compute the expire time with scale factor.
Ouch, of course you're right.
> So here we should use a binding of timer_mod_ns() - Timer::modify_ns()
> instead of Timer::modify(), just like C side did.
>
> Moreover, for Timer::modify_ns() & Timer::modify(), the simplest
> way is to build them based on timer_mod_ns() & timer_mod() (but this
> sounds like shifting the responsibility for type checking and overflow
> checking to the C side :-( ).
>
> Alternative, we can make Timer::modify() based on Timer::modify_ns(),
> but then it involves many numeric type conversions: scale is i32 but
> expire_time is u64, and Timer::modify_ns() may accept a u64 argument.
>
> Fortunately,, we can make Timer's modify() accept i64 to reduce type
> conversions.
I think it's better to make it accept u64 and assert that it's not
above i64::MAX (with .try_into().unwrap()). Anyway I left out this
patch, and it can be picked up when HPET starts using
ToMigrationState.
Paolo
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 11/11] rust: migration: implement ToMigrationState as part of impl_vmstate_bitsized
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (9 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 10/11] rust: migration: implement ToMigrationState for Timer Paolo Bonzini
@ 2025-10-01 7:52 ` Paolo Bonzini
2025-10-14 5:18 ` Zhao Liu
2025-10-01 8:00 ` [PATCH preview 00/14] rust: QObject and QAPI bindings Paolo Bonzini
` (14 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 7:52 UTC (permalink / raw)
To: qemu-devel; +Cc: Zhao Liu
This is most likely desirable, and is the easiest way to migrate
a bit-sized value without peeking at the innards of the bilge crate.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/migration/src/vmstate.rs | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index 2a29aff7cd6..c95f8ece776 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -295,6 +295,25 @@ unsafe impl $crate::vmstate::VMState for $type {
as ::bilge::prelude::Number>::UnderlyingType
as $crate::vmstate::VMState>::VARRAY_FLAG;
}
+
+ impl $crate::migratable::ToMigrationState for $type {
+ type Migrated = <<$type as ::bilge::prelude::Bitsized>::ArbitraryInt
+ as ::bilge::prelude::Number>::UnderlyingType;
+
+ fn snapshot_migration_state(&self, target: &mut Self::Migrated) -> Result<(), $crate::InvalidError> {
+ *target = Self::Migrated::from(*self);
+ Ok(())
+ }
+
+ fn restore_migrated_state_mut(
+ &mut self,
+ source: Self::Migrated,
+ version_id: u8,
+ ) -> Result<(), $crate::InvalidError> {
+ *self = Self::from(source);
+ Ok(())
+ }
+ }
};
}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 11/11] rust: migration: implement ToMigrationState as part of impl_vmstate_bitsized
2025-10-01 7:52 ` [PATCH 11/11] rust: migration: implement ToMigrationState as part of impl_vmstate_bitsized Paolo Bonzini
@ 2025-10-14 5:18 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-14 5:18 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
On Wed, Oct 01, 2025 at 09:52:10AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 09:52:10 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 11/11] rust: migration: implement ToMigrationState as part
> of impl_vmstate_bitsized
> X-Mailer: git-send-email 2.51.0
>
> This is most likely desirable, and is the easiest way to migrate
> a bit-sized value without peeking at the innards of the bilge crate.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/migration/src/vmstate.rs | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH preview 00/14] rust: QObject and QAPI bindings
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (10 preceding siblings ...)
2025-10-01 7:52 ` [PATCH 11/11] rust: migration: implement ToMigrationState as part of impl_vmstate_bitsized Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 01/14] qobject: make refcount atomic Paolo Bonzini
` (13 subsequent siblings)
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
This adds two related parts of the Rust bindings:
- QAPI code generator that creates Rust structs from the JSON
description. The structs are *not* ABI compatible with the
C ones, instead they use native Rust data types.
- QObject bindings and (de)serialization support, which can be used to
convert QObjects to and from QAPI structs.
Unfortunately Rust code is not able to use visitors, other than by
creating an intermediate QObject. This is because of the different
architecture of serde vs. QAPI visitors, and because visitor's
dual-purpose functions, where the same function is used by both input and
output visitors, rely heavily on the structs using the same representation
as the visitor arguments (for example NUL-terminated strings.
The serde format implementation was co-authored by me and Marc-André.
Marc-André did all the bug fixing and integration testing; and there
are a lot more bugs to be fixed / tests to be written, so this is just
a preview.
Paolo
Marc-André Lureau (7):
rust/qobject: add Display/Debug
scripts/qapi: add QAPISchemaIfCond.rsgen()
scripts/qapi: generate high-level Rust bindings
scripts/qapi: strip trailing whitespaces
scripts/rustc_args: add --no-strict-cfg
rust/util: build QAPI types
rust: start qapi tests
Paolo Bonzini (7):
qobject: make refcount atomic
rust: add basic QObject bindings
subprojects: add serde
rust: add Serialize implementation for QObject
rust: add Serializer (to_qobject) implementation for QObject
rust: add Deserialize implementation for QObject
rust: add Deserializer (from_qobject) implementation for QObject
docs/devel/rust.rst | 1 +
meson.build | 4 +-
include/qobject/qobject.h | 5 +-
rust/util/wrapper.h | 8 +
qapi/meson.build | 6 +
rust/Cargo.lock | 2 +
rust/Cargo.toml | 2 +
rust/meson.build | 2 +
rust/tests/meson.build | 10 +-
rust/tests/tests/integration.rs | 2 +
rust/tests/tests/qapi.rs | 35 ++
rust/util/Cargo.toml | 2 +
rust/util/meson.build | 31 +-
rust/util/src/lib.rs | 2 +
rust/util/src/qobject/deserialize.rs | 134 ++++
rust/util/src/qobject/deserializer.rs | 373 +++++++++++
rust/util/src/qobject/error.rs | 58 ++
rust/util/src/qobject/mod.rs | 353 +++++++++++
rust/util/src/qobject/serialize.rs | 59 ++
rust/util/src/qobject/serializer.rs | 585 ++++++++++++++++++
scripts/archive-source.sh | 3 +
scripts/make-release | 2 +-
scripts/qapi/backend.py | 28 +-
scripts/qapi/common.py | 16 +
scripts/qapi/gen.py | 6 +-
scripts/qapi/main.py | 4 +-
scripts/qapi/rs.py | 176 ++++++
scripts/qapi/rs_types.py | 354 +++++++++++
scripts/qapi/schema.py | 4 +
scripts/rust/rustc_args.py | 16 +-
subprojects/.gitignore | 3 +
.../packagefiles/serde-1-rs/meson.build | 36 ++
.../packagefiles/serde-1.0.226-include.patch | 16 +
.../packagefiles/serde_core-1-rs/meson.build | 25 +
.../serde_core-1.0.226-include.patch | 15 +
.../serde_derive-1-rs/meson.build | 35 ++
.../serde_derive-1.0.226-include.patch | 11 +
subprojects/serde-1-rs.wrap | 11 +
subprojects/serde_core-1-rs.wrap | 11 +
subprojects/serde_derive-1-rs.wrap | 11 +
40 files changed, 2438 insertions(+), 19 deletions(-)
create mode 100644 rust/tests/tests/integration.rs
create mode 100644 rust/tests/tests/qapi.rs
create mode 100644 rust/util/src/qobject/deserialize.rs
create mode 100644 rust/util/src/qobject/deserializer.rs
create mode 100644 rust/util/src/qobject/error.rs
create mode 100644 rust/util/src/qobject/mod.rs
create mode 100644 rust/util/src/qobject/serialize.rs
create mode 100644 rust/util/src/qobject/serializer.rs
create mode 100644 scripts/qapi/rs.py
create mode 100644 scripts/qapi/rs_types.py
create mode 100644 subprojects/packagefiles/serde-1-rs/meson.build
create mode 100644 subprojects/packagefiles/serde-1.0.226-include.patch
create mode 100644 subprojects/packagefiles/serde_core-1-rs/meson.build
create mode 100644 subprojects/packagefiles/serde_core-1.0.226-include.patch
create mode 100644 subprojects/packagefiles/serde_derive-1-rs/meson.build
create mode 100644 subprojects/packagefiles/serde_derive-1.0.226-include.patch
create mode 100644 subprojects/serde-1-rs.wrap
create mode 100644 subprojects/serde_core-1-rs.wrap
create mode 100644 subprojects/serde_derive-1-rs.wrap
--
2.51.0
^ permalink raw reply [flat|nested] 55+ messages in thread* [PATCH 01/14] qobject: make refcount atomic
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (11 preceding siblings ...)
2025-10-01 8:00 ` [PATCH preview 00/14] rust: QObject and QAPI bindings Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-13 7:51 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 02/14] rust: add basic QObject bindings Paolo Bonzini
` (12 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
The Rust bindings for QObject will only share a complete
object and treat it as immutable from that point on. With
that constraint, it is trivial to make QObjects thread-safe
just by making reference count operations atomic. Do the
same when the C code adds or removes references.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/qobject/qobject.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/qobject/qobject.h b/include/qobject/qobject.h
index a6244d0ce00..02f4c6a6eb2 100644
--- a/include/qobject/qobject.h
+++ b/include/qobject/qobject.h
@@ -32,6 +32,7 @@
#ifndef QOBJECT_H
#define QOBJECT_H
+#include "qemu/atomic.h"
#include "qapi/qapi-builtin-types.h"
/* Not for use outside include/qobject/ */
@@ -73,7 +74,7 @@ QEMU_BUILD_BUG_MSG(QTYPE__MAX != 7,
static inline void qobject_ref_impl(QObject *obj)
{
if (obj) {
- obj->base.refcnt++;
+ qatomic_inc(&obj->base.refcnt);
}
}
@@ -95,7 +96,7 @@ void qobject_destroy(QObject *obj);
static inline void qobject_unref_impl(QObject *obj)
{
assert(!obj || obj->base.refcnt);
- if (obj && --obj->base.refcnt == 0) {
+ if (obj && qatomic_fetch_dec(&obj->base.refcnt) == 1) {
qobject_destroy(obj);
}
}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 01/14] qobject: make refcount atomic
2025-10-01 8:00 ` [PATCH 01/14] qobject: make refcount atomic Paolo Bonzini
@ 2025-10-13 7:51 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-10-13 7:51 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On Wed, Oct 01, 2025 at 10:00:38AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 10:00:38 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 01/14] qobject: make refcount atomic
> X-Mailer: git-send-email 2.51.0
>
> The Rust bindings for QObject will only share a complete
> object and treat it as immutable from that point on. With
> that constraint, it is trivial to make QObjects thread-safe
> just by making reference count operations atomic. Do the
> same when the C code adds or removes references.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> include/qobject/qobject.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 02/14] rust: add basic QObject bindings
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (12 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 01/14] qobject: make refcount atomic Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-12-04 14:15 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 03/14] subprojects: add serde Paolo Bonzini
` (11 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
This is only a basic API, intended to be used by the serde traits.
Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/util/wrapper.h | 7 +
rust/util/meson.build | 6 +-
rust/util/src/lib.rs | 2 +
rust/util/src/qobject/mod.rs | 309 +++++++++++++++++++++++++++++++++++
4 files changed, 322 insertions(+), 2 deletions(-)
create mode 100644 rust/util/src/qobject/mod.rs
diff --git a/rust/util/wrapper.h b/rust/util/wrapper.h
index b9ed68a01d8..0907dd59142 100644
--- a/rust/util/wrapper.h
+++ b/rust/util/wrapper.h
@@ -30,3 +30,10 @@ typedef enum memory_order {
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/timer.h"
+#include "qobject/qnull.h"
+#include "qobject/qbool.h"
+#include "qobject/qnum.h"
+#include "qobject/qstring.h"
+#include "qobject/qobject.h"
+#include "qobject/qlist.h"
+#include "qobject/qdict.h"
diff --git a/rust/util/meson.build b/rust/util/meson.build
index b0b75e93ff6..38da1ba8cd1 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -36,8 +36,10 @@ _util_rs = static_library(
'src/module.rs',
'src/timer.rs',
],
- {'.': _util_bindings_inc_rs}
- ),
+ {'.': _util_bindings_inc_rs,
+ 'qobject': [
+ 'src/qobject/mod.rs',
+ ]}),
override_options: ['rust_std=2021', 'build.rust_std=2021'],
rust_abi: 'rust',
dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs, qom, qemuutil],
diff --git a/rust/util/src/lib.rs b/rust/util/src/lib.rs
index 16c89b95174..fe0128103c8 100644
--- a/rust/util/src/lib.rs
+++ b/rust/util/src/lib.rs
@@ -4,6 +4,8 @@
pub mod error;
pub mod log;
pub mod module;
+#[macro_use]
+pub mod qobject;
pub mod timer;
pub use error::{Error, Result};
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
new file mode 100644
index 00000000000..f43d87a3b66
--- /dev/null
+++ b/rust/util/src/qobject/mod.rs
@@ -0,0 +1,309 @@
+//! `QObject` bindings
+//!
+//! This module implements bindings for QEMU's `QObject` data structure.
+//! The bindings integrate with `serde`, which take the role of visitors
+//! in Rust code.
+
+#![deny(clippy::unwrap_used)]
+
+use std::{
+ cell::UnsafeCell,
+ ffi::{c_char, CString},
+ mem::ManuallyDrop,
+ ptr::{addr_of, addr_of_mut},
+ sync::atomic::{AtomicUsize, Ordering},
+};
+
+use common::assert_field_type;
+
+use crate::bindings;
+
+/// A wrapper for a C `QObject`.
+///
+/// Because `QObject` is not thread-safe, the safety of these bindings
+/// right now hinges on treating them as immutable. It is part of the
+/// contract with the `QObject` constructors that the Rust struct is
+/// only built after the contents are stable.
+///
+/// Only a bare bones API is public; production and consumption of `QObject`
+/// generally goes through `serde`.
+pub struct QObject(&'static UnsafeCell<bindings::QObject>);
+
+// SAFETY: the QObject API are not thread-safe other than reference counting;
+// but the Rust struct is only created once the contents are stable, and
+// therefore it obeys the aliased XOR mutable invariant.
+unsafe impl Send for QObject {}
+unsafe impl Sync for QObject {}
+
+impl QObject {
+ /// Construct a [`QObject`] from a C `QObjectBase` pointer.
+ /// The caller cedes its reference to the returned struct.
+ ///
+ /// # Safety
+ ///
+ /// The `QObjectBase` must not be changed from C code while
+ /// the Rust `QObject` lives
+ const unsafe fn from_base(p: *const bindings::QObjectBase_) -> Self {
+ QObject(unsafe { &*p.cast() })
+ }
+
+ /// Construct a [`QObject`] from a C `QObject` pointer.
+ /// The caller cedes its reference to the returned struct.
+ ///
+ /// # Safety
+ ///
+ /// The `QObject` must not be changed from C code while
+ /// the Rust `QObject` lives
+ pub const unsafe fn from_raw(p: *const bindings::QObject) -> Self {
+ QObject(unsafe { &*p.cast() })
+ }
+
+ /// Obtain a raw C pointer from a reference. `self` is consumed
+ /// and the C `QObject` pointer is leaked.
+ pub fn into_raw(self) -> *mut bindings::QObject {
+ let src = ManuallyDrop::new(self);
+ src.0.get()
+ }
+
+ /// Construct a [`QObject`] from a C `QObject` pointer.
+ /// The caller *does not* cede its reference to the returned struct.
+ ///
+ /// # Safety
+ ///
+ /// The `QObjectBase` must not be changed from C code while
+ /// the Rust `QObject` lives
+ unsafe fn cloned_from_base(p: *const bindings::QObjectBase_) -> Self {
+ let orig = unsafe { ManuallyDrop::new(QObject::from_base(p)) };
+ (*orig).clone()
+ }
+
+ /// Construct a [`QObject`] from a C `QObject` pointer.
+ /// The caller *does not* cede its reference to the returned struct.
+ ///
+ /// # Safety
+ ///
+ /// The `QObject` must not be changed from C code while
+ /// the Rust `QObject` lives
+ pub unsafe fn cloned_from_raw(p: *const bindings::QObject) -> Self {
+ let orig = unsafe { ManuallyDrop::new(QObject::from_raw(p)) };
+ (*orig).clone()
+ }
+
+ fn refcnt(&self) -> &AtomicUsize {
+ assert_field_type!(bindings::QObjectBase_, refcnt, usize);
+ let qobj = self.0.get();
+ unsafe { AtomicUsize::from_ptr(addr_of_mut!((*qobj).base.refcnt)) }
+ }
+}
+
+impl From<()> for QObject {
+ fn from(_null: ()) -> Self {
+ unsafe { QObject::cloned_from_base(addr_of!(bindings::qnull_.base)) }
+ }
+}
+
+impl<T> From<Option<T>> for QObject
+where
+ QObject: From<T>,
+{
+ fn from(o: Option<T>) -> Self {
+ o.map_or_else(|| ().into(), Into::into)
+ }
+}
+
+impl From<bool> for QObject {
+ fn from(b: bool) -> Self {
+ let qobj = unsafe { &*bindings::qbool_from_bool(b) };
+ unsafe { QObject::from_base(addr_of!(qobj.base)) }
+ }
+}
+
+macro_rules! from_int {
+ ($t:ty) => {
+ impl From<$t> for QObject {
+ fn from(n: $t) -> Self {
+ let qobj = unsafe { &*bindings::qnum_from_int(n.into()) };
+ unsafe { QObject::from_base(addr_of!(qobj.base)) }
+ }
+ }
+ };
+}
+
+from_int!(i8);
+from_int!(i16);
+from_int!(i32);
+from_int!(i64);
+
+macro_rules! from_uint {
+ ($t:ty) => {
+ impl From<$t> for QObject {
+ fn from(n: $t) -> Self {
+ let qobj = unsafe { &*bindings::qnum_from_uint(n.into()) };
+ unsafe { QObject::from_base(addr_of!(qobj.base)) }
+ }
+ }
+ };
+}
+
+from_uint!(u8);
+from_uint!(u16);
+from_uint!(u32);
+from_uint!(u64);
+
+macro_rules! from_double {
+ ($t:ty) => {
+ impl From<$t> for QObject {
+ fn from(n: $t) -> Self {
+ let qobj = unsafe { &*bindings::qnum_from_double(n.into()) };
+ unsafe { QObject::from_base(addr_of!(qobj.base)) }
+ }
+ }
+ };
+}
+
+from_double!(f32);
+from_double!(f64);
+
+impl From<CString> for QObject {
+ fn from(s: CString) -> Self {
+ let qobj = unsafe { &*bindings::qstring_from_str(s.as_ptr()) };
+ unsafe { QObject::from_base(addr_of!(qobj.base)) }
+ }
+}
+
+impl<A> FromIterator<A> for QObject
+where
+ Self: From<A>,
+{
+ fn from_iter<I: IntoIterator<Item = A>>(it: I) -> Self {
+ let qlist = unsafe { &mut *bindings::qlist_new() };
+ for elem in it {
+ let elem: QObject = elem.into();
+ let elem: *mut bindings::QObject = elem.0.get();
+ unsafe {
+ bindings::qlist_append_obj(qlist, elem);
+ }
+ }
+ unsafe { QObject::from_base(addr_of!(qlist.base)) }
+ }
+}
+
+impl<A> FromIterator<(CString, A)> for QObject
+where
+ Self: From<A>,
+{
+ fn from_iter<I: IntoIterator<Item = (CString, A)>>(it: I) -> Self {
+ let qdict = unsafe { &mut *bindings::qdict_new() };
+ for (key, val) in it {
+ let val: QObject = val.into();
+ let val = val.into_raw();
+ unsafe {
+ bindings::qdict_put_obj(qdict, key.as_ptr().cast::<c_char>(), val);
+ }
+ }
+ unsafe { QObject::from_base(addr_of!(qdict.base)) }
+ }
+}
+
+impl Clone for QObject {
+ fn clone(&self) -> Self {
+ self.refcnt().fetch_add(1, Ordering::Acquire);
+ QObject(self.0)
+ }
+}
+
+impl Drop for QObject {
+ fn drop(&mut self) {
+ if self.refcnt().fetch_sub(1, Ordering::Release) == 1 {
+ unsafe {
+ bindings::qobject_destroy(self.0.get());
+ }
+ }
+ }
+}
+
+#[allow(unused)]
+macro_rules! match_qobject {
+ (@internal ($qobj:expr) =>
+ $(() => $unit:expr,)?
+ $(bool($boolvar:tt) => $bool:expr,)?
+ $(i64($i64var:tt) => $i64:expr,)?
+ $(u64($u64var:tt) => $u64:expr,)?
+ $(f64($f64var:tt) => $f64:expr,)?
+ $(CStr($cstrvar:tt) => $cstr:expr,)?
+ $(QList($qlistvar:tt) => $qlist:expr,)?
+ $(QDict($qdictvar:tt) => $qdict:expr,)?
+ $(_ => $other:expr,)?
+ ) => {
+ loop {
+ let qobj_ = $qobj.0.get();
+ match unsafe { &* qobj_ }.base.type_ {
+ $($crate::bindings::QTYPE_QNULL => break $unit,)?
+ $($crate::bindings::QTYPE_QBOOL => break {
+ let qbool__: *mut $crate::bindings::QBool = qobj_.cast();
+ let $boolvar = unsafe { (&*qbool__).value };
+ $bool
+ },)?
+ $crate::bindings::QTYPE_QNUM => {
+ let qnum__: *mut $crate::bindings::QNum = qobj_.cast();
+ let qnum__ = unsafe { &*qnum__ };
+ match qnum__.kind {
+ $crate::bindings::QNUM_I64 |
+ $crate::bindings::QNUM_U64 |
+ $crate::bindings::QNUM_DOUBLE => {}
+ _ => {
+ panic!("unreachable");
+ }
+ }
+
+ match qnum__.kind {
+ $($crate::bindings::QNUM_I64 => break {
+ let $i64var = unsafe { qnum__.u.i64_ };
+ $i64
+ },)?
+ $($crate::bindings::QNUM_U64 => break {
+ let $u64var = unsafe { qnum__.u.u64_ };
+ $u64
+ },)?
+ $($crate::bindings::QNUM_DOUBLE => break {
+ let $f64var = unsafe { qnum__.u.dbl };
+ $f64
+ },)?
+ _ => {}
+ }
+ },
+ $($crate::bindings::QTYPE_QSTRING => break {
+ let qstring__: *mut $crate::bindings::QString = qobj_.cast();
+ let $cstrvar = unsafe { ::core::ffi::CStr::from_ptr((&*qstring__).string) };
+ $cstr
+ },)?
+ $($crate::bindings::QTYPE_QLIST => break {
+ let qlist__: *mut $crate::bindings::QList = qobj_.cast();
+ let $qlistvar = unsafe { &*qlist__ };
+ $qlist
+ },)?
+ $($crate::bindings::QTYPE_QDICT => break {
+ let qdict__: *mut $crate::bindings::QDict = qobj_.cast();
+ let $qdictvar = unsafe { &*qdict__ };
+ $qdict
+ },)?
+ _ => ()
+ };
+ $(break $other;)?
+ #[allow(unreachable_code)]
+ {
+ panic!("unreachable");
+ }
+ }
+ };
+
+ // first cleanup the syntax a bit, checking that there's at least
+ // one pattern and always adding a trailing comma
+ (($qobj:expr) =>
+ $($type:tt$(($val:tt))? => $code:expr ),+ $(,)?) => {
+ match_qobject!(@internal ($qobj) =>
+ $($type $(($val))? => $code,)+)
+ };
+}
+#[allow(unused_imports)]
+use match_qobject;
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 02/14] rust: add basic QObject bindings
2025-10-01 8:00 ` [PATCH 02/14] rust: add basic QObject bindings Paolo Bonzini
@ 2025-12-04 14:15 ` Zhao Liu
2025-12-04 14:18 ` Paolo Bonzini
0 siblings, 1 reply; 55+ messages in thread
From: Zhao Liu @ 2025-12-04 14:15 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
> diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
> new file mode 100644
> index 00000000000..f43d87a3b66
> --- /dev/null
> +++ b/rust/util/src/qobject/mod.rs
> @@ -0,0 +1,309 @@
> +//! `QObject` bindings
> +//!
> +//! This module implements bindings for QEMU's `QObject` data structure.
> +//! The bindings integrate with `serde`, which take the role of visitors
> +//! in Rust code.
> +
> +#![deny(clippy::unwrap_used)]
Are there are any specific considerations for this lint rule?
> +use std::{
> + cell::UnsafeCell,
> + ffi::{c_char, CString},
> + mem::ManuallyDrop,
> + ptr::{addr_of, addr_of_mut},
> + sync::atomic::{AtomicUsize, Ordering},
> +};
> +
> +use common::assert_field_type;
> +
> +use crate::bindings;
> +
> +/// A wrapper for a C `QObject`.
> +///
> +/// Because `QObject` is not thread-safe, the safety of these bindings
> +/// right now hinges on treating them as immutable. It is part of the
> +/// contract with the `QObject` constructors that the Rust struct is
> +/// only built after the contents are stable.
> +///
> +/// Only a bare bones API is public; production and consumption of `QObject`
> +/// generally goes through `serde`.
> +pub struct QObject(&'static UnsafeCell<bindings::QObject>);
It seems Opaque<> feels more natural than UnsafeCell<>.
Opaque::from_raw() requires *mut T, but QObject::from_raw() and
QObject::clone_from_raw() mainly play with C bindings which usually use
*mut pointer. So it seems unnecessary to convert *mut to *const in the
middle.
And furthermore, I think QObject(Opaque<bindings::QObject>) is better
than QObject(&'static Opaque<bindings::QObject>). From a semantic view,
C's QObject is a struct, while Rust's QObject is a reference, which seems
somewhat mismatched.
I'm not sure yet if there may be gaps when remove &'static, but it
looks like using &'static Opaque<> instead of &'static UnsafeCell<> is
Okay in code?
> + /// Construct a [`QObject`] from a C `QObject` pointer.
> + /// The caller *does not* cede its reference to the returned struct.
> + ///
> + /// # Safety
> + ///
> + /// The `QObjectBase` must not be changed from C code while
> + /// the Rust `QObject` lives
> + unsafe fn cloned_from_base(p: *const bindings::QObjectBase_) -> Self {
> + let orig = unsafe { ManuallyDrop::new(QObject::from_base(p)) };
> + (*orig).clone()
> + }
> +
> + /// Construct a [`QObject`] from a C `QObject` pointer.
> + /// The caller *does not* cede its reference to the returned struct.
> + ///
> + /// # Safety
> + ///
> + /// The `QObject` must not be changed from C code while
> + /// the Rust `QObject` lives
> + pub unsafe fn cloned_from_raw(p: *const bindings::QObject) -> Self {
> + let orig = unsafe { ManuallyDrop::new(QObject::from_raw(p)) };
> + (*orig).clone()
> + }
These 2 methods are the clone, but it seems they're actually similar to
Owned<>, i.e., increase refcnt when Rust side wants to "own" or ensure
to use this safely.
However, there indeed isn't a non-object version of Owned for now, so I
think this kind of clone should be okay. Hmm, for long-term, is it
valuable to consider a more generic Owned<>?
> +impl<A> FromIterator<A> for QObject
> +where
> + Self: From<A>,
> +{
> + fn from_iter<I: IntoIterator<Item = A>>(it: I) -> Self {
nit: maybe the name "iter" is better than "it"?
> + let qlist = unsafe { &mut *bindings::qlist_new() };
> + for elem in it {
> + let elem: QObject = elem.into();
> + let elem: *mut bindings::QObject = elem.0.get();
> + unsafe {
> + bindings::qlist_append_obj(qlist, elem);
> + }
> + }
> + unsafe { QObject::from_base(addr_of!(qlist.base)) }
> + }
> +}
> +
> +impl<A> FromIterator<(CString, A)> for QObject
> +where
> + Self: From<A>,
> +{
> + fn from_iter<I: IntoIterator<Item = (CString, A)>>(it: I) -> Self {
ditto.
> + let qdict = unsafe { &mut *bindings::qdict_new() };
> + for (key, val) in it {
> + let val: QObject = val.into();
> + let val = val.into_raw();
> + unsafe {
> + bindings::qdict_put_obj(qdict, key.as_ptr().cast::<c_char>(), val);
> + }
> + }
> + unsafe { QObject::from_base(addr_of!(qdict.base)) }
> + }
> +}
I think these the mappings of qdict and qlist look quite good.
> +#[allow(unused)]
> +macro_rules! match_qobject {
> + (@internal ($qobj:expr) =>
> + $(() => $unit:expr,)?
> + $(bool($boolvar:tt) => $bool:expr,)?
> + $(i64($i64var:tt) => $i64:expr,)?
> + $(u64($u64var:tt) => $u64:expr,)?
> + $(f64($f64var:tt) => $f64:expr,)?
> + $(CStr($cstrvar:tt) => $cstr:expr,)?
> + $(QList($qlistvar:tt) => $qlist:expr,)?
> + $(QDict($qdictvar:tt) => $qdict:expr,)?
> + $(_ => $other:expr,)?
> + ) => {
> + loop {
> + let qobj_ = $qobj.0.get();
> + match unsafe { &* qobj_ }.base.type_ {
> + $($crate::bindings::QTYPE_QNULL => break $unit,)?
> + $($crate::bindings::QTYPE_QBOOL => break {
> + let qbool__: *mut $crate::bindings::QBool = qobj_.cast();
> + let $boolvar = unsafe { (&*qbool__).value };
> + $bool
> + },)?
> + $crate::bindings::QTYPE_QNUM => {
> + let qnum__: *mut $crate::bindings::QNum = qobj_.cast();
> + let qnum__ = unsafe { &*qnum__ };
> + match qnum__.kind {
> + $crate::bindings::QNUM_I64 |
> + $crate::bindings::QNUM_U64 |
> + $crate::bindings::QNUM_DOUBLE => {}
> + _ => {
> + panic!("unreachable");
> + }
> + }
> +
> + match qnum__.kind {
> + $($crate::bindings::QNUM_I64 => break {
> + let $i64var = unsafe { qnum__.u.i64_ };
> + $i64
> + },)?
> + $($crate::bindings::QNUM_U64 => break {
> + let $u64var = unsafe { qnum__.u.u64_ };
> + $u64
> + },)?
> + $($crate::bindings::QNUM_DOUBLE => break {
> + let $f64var = unsafe { qnum__.u.dbl };
> + $f64
> + },)?
> + _ => {}
I think this doesn't handle a special case: qobj's QNUM type doesn't
macth the value type, for example, qobj is QNUM_U64 but value is i64.
Though external code won't use this macro, I think panic may be better
than {}?
> + }
Thurther, there're 2 match blocks. Could we merge them as one?
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index 292a3c9c2385..4053a3b7610d 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -280,14 +280,6 @@ macro_rules! match_qobject {
$crate::bindings::QTYPE_QNUM => {
let qnum__: *mut $crate::bindings::QNum = qobj_.cast();
let qnum__ = unsafe { &*qnum__ };
- match qnum__.kind {
- $crate::bindings::QNUM_I64 |
- $crate::bindings::QNUM_U64 |
- $crate::bindings::QNUM_DOUBLE => {}
- _ => {
- panic!("unreachable");
- }
- }
match qnum__.kind {
$($crate::bindings::QNUM_I64 => break {
@@ -302,7 +294,9 @@ macro_rules! match_qobject {
let $f64var = unsafe { qnum__.u.dbl };
$f64
},)?
- _ => {}
+ _ => {
+ panic!("unreachable");
+ }
}
},
$($crate::bindings::QTYPE_QSTRING => break {
Regards,
Zhao
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 02/14] rust: add basic QObject bindings
2025-12-04 14:15 ` Zhao Liu
@ 2025-12-04 14:18 ` Paolo Bonzini
2025-12-05 6:30 ` Zhao Liu
2025-12-05 11:30 ` Paolo Bonzini
0 siblings, 2 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-12-04 14:18 UTC (permalink / raw)
To: Zhao Liu; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On 12/4/25 15:15, Zhao Liu wrote:
>> diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
>> new file mode 100644
>> index 00000000000..f43d87a3b66
>> --- /dev/null
>> +++ b/rust/util/src/qobject/mod.rs
>> @@ -0,0 +1,309 @@
>> +//! `QObject` bindings
>> +//!
>> +//! This module implements bindings for QEMU's `QObject` data structure.
>> +//! The bindings integrate with `serde`, which take the role of visitors
>> +//! in Rust code.
>> +
>> +#![deny(clippy::unwrap_used)]
>
> Are there are any specific considerations for this lint rule?
It ensures that all conversion errors (e.g. from try_into()) are propagated.
>> +pub struct QObject(&'static UnsafeCell<bindings::QObject>);
>
> It seems Opaque<> feels more natural than UnsafeCell<>.
>
> Opaque::from_raw() requires *mut T, but QObject::from_raw() and
> QObject::clone_from_raw() mainly play with C bindings which usually use
> *mut pointer. So it seems unnecessary to convert *mut to *const in the
> middle.
>
> And furthermore, I think QObject(Opaque<bindings::QObject>) is better
> than QObject(&'static Opaque<bindings::QObject>). From a semantic view,
> C's QObject is a struct, while Rust's QObject is a reference, which seems
> somewhat mismatched.
>
> I'm not sure yet if there may be gaps when remove &'static, but it
> looks like using &'static Opaque<> instead of &'static UnsafeCell<> is
> Okay in code?
I am using UnsafeCell because the QObject here is always valid, i.e.
MaybeUninit is explicitly not necessary. Opaque explicitly allows it to
be invalid, here instead the API is "create via C code or FFI and only
then create the QObject".
However, while it is possible to use Opaque<> instead of UnsafeCell<>,
it is not possible to make this a simple wrapper because QObject is
unmovable and reference counted. That is, QObject is the equivalent of
(for example) Owned<DeviceState>.
> These 2 methods are the clone, but it seems they're actually similar to
> Owned<>, i.e., increase refcnt when Rust side wants to "own" or ensure
> to use this safely.
>
> However, there indeed isn't a non-object version of Owned for now, so I
> think this kind of clone should be okay. Hmm, for long-term, is it
> valuable to consider a more generic Owned<>?
Linux has ARef<> I think. But it seems overkill for now.
>> +impl<A> FromIterator<A> for QObject
>> +where
>> + Self: From<A>,
>> +{
>> + fn from_iter<I: IntoIterator<Item = A>>(it: I) -> Self {
>
> nit: maybe the name "iter" is better than "it"?
Sure.
>> + match qnum__.kind {
>> + $($crate::bindings::QNUM_I64 => break {
>> + let $i64var = unsafe { qnum__.u.i64_ };
>> + $i64
>> + },)?
>> + $($crate::bindings::QNUM_U64 => break {
>> + let $u64var = unsafe { qnum__.u.u64_ };
>> + $u64
>> + },)?
>> + $($crate::bindings::QNUM_DOUBLE => break {
>> + let $f64var = unsafe { qnum__.u.dbl };
>> + $f64
>> + },)?
>> + _ => {}
>
> I think this doesn't handle a special case: qobj's QNUM type doesn't
> macth the value type, for example, qobj is QNUM_U64 but value is i64.
>
> Though external code won't use this macro, I think panic may be better
> than {}?>
> Thurther, there're 2 match blocks. Could we merge them as one?
Yes, that works because all callers specify all three of i64/u64/f64.
Paolo
^ permalink raw reply [flat|nested] 55+ messages in thread* Re: [PATCH 02/14] rust: add basic QObject bindings
2025-12-04 14:18 ` Paolo Bonzini
@ 2025-12-05 6:30 ` Zhao Liu
2025-12-05 11:30 ` Paolo Bonzini
1 sibling, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-12-05 6:30 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
> > > +pub struct QObject(&'static UnsafeCell<bindings::QObject>);
> >
> > It seems Opaque<> feels more natural than UnsafeCell<>.
> >
> > Opaque::from_raw() requires *mut T, but QObject::from_raw() and
> > QObject::clone_from_raw() mainly play with C bindings which usually use
> > *mut pointer. So it seems unnecessary to convert *mut to *const in the
> > middle.
> >
> > And furthermore, I think QObject(Opaque<bindings::QObject>) is better
> > than QObject(&'static Opaque<bindings::QObject>). From a semantic view,
> > C's QObject is a struct, while Rust's QObject is a reference, which seems
> > somewhat mismatched.
> >
> > I'm not sure yet if there may be gaps when remove &'static, but it
> > looks like using &'static Opaque<> instead of &'static UnsafeCell<> is
> > Okay in code?
>
> I am using UnsafeCell because the QObject here is always valid, i.e.
> MaybeUninit is explicitly not necessary. Opaque explicitly allows it to be
> invalid, here instead the API is "create via C code or FFI and only then
> create the QObject".
Just want to clarify the use for Opaque, we've already used Opaque<>::from_raw()
for the case "create via C code or FFI and only then create the" something? In
DeviceState::init_clock_[in|out](), and ObjectClassMethods::new().
But I also agree, for this case MaybeUninit is not necessary. And PhantomPinned
is simply replaced by &'static.
> However, while it is possible to use Opaque<> instead of UnsafeCell<>, it is
> not possible to make this a simple wrapper because QObject is unmovable and
> reference counted. That is, QObject is the equivalent of (for example)
> Owned<DeviceState>.
Got it, if Rust owns data by QObject(Opaque<>) but without Owned<>, this
can't work since it's no way to handle refcnt.
So &'static UnsafeCell<> is the simplest way to meet both unmovable &
refcnt rquirements.
I'm good with this design. Thanks!
Regards,
Zhao
^ permalink raw reply [flat|nested] 55+ messages in thread
* Re: [PATCH 02/14] rust: add basic QObject bindings
2025-12-04 14:18 ` Paolo Bonzini
2025-12-05 6:30 ` Zhao Liu
@ 2025-12-05 11:30 ` Paolo Bonzini
1 sibling, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-12-05 11:30 UTC (permalink / raw)
To: Zhao Liu; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On 12/4/25 15:18, Paolo Bonzini wrote:
> On 12/4/25 15:15, Zhao Liu wrote:
>>> diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
>>> new file mode 100644
>>> index 00000000000..f43d87a3b66
>>> --- /dev/null
>>> +++ b/rust/util/src/qobject/mod.rs
>>> @@ -0,0 +1,309 @@
>>> +//! `QObject` bindings
>>> +//!
>>> +//! This module implements bindings for QEMU's `QObject` data
>>> structure.
>>> +//! The bindings integrate with `serde`, which take the role of
>>> visitors
>>> +//! in Rust code.
>>> +
>>> +#![deny(clippy::unwrap_used)]
>>
>> Are there are any specific considerations for this lint rule?
>
> It ensures that all conversion errors (e.g. from try_into()) are
> propagated.
>
>>> +pub struct QObject(&'static UnsafeCell<bindings::QObject>);
>>
>> It seems Opaque<> feels more natural than UnsafeCell<>.
>>
>> Opaque::from_raw() requires *mut T, but QObject::from_raw() and
>> QObject::clone_from_raw() mainly play with C bindings which usually use
>> *mut pointer. So it seems unnecessary to convert *mut to *const in the
>> middle.
>>
>> And furthermore, I think QObject(Opaque<bindings::QObject>) is better
>> than QObject(&'static Opaque<bindings::QObject>). From a semantic view,
>> C's QObject is a struct, while Rust's QObject is a reference, which seems
>> somewhat mismatched.
>>
>> I'm not sure yet if there may be gaps when remove &'static, but it
>> looks like using &'static Opaque<> instead of &'static UnsafeCell<> is
>> Okay in code?
>
> I am using UnsafeCell because the QObject here is always valid, i.e.
> MaybeUninit is explicitly not necessary. Opaque explicitly allows it to
> be invalid, here instead the API is "create via C code or FFI and only
> then create the QObject".
>
> However, while it is possible to use Opaque<> instead of UnsafeCell<>,
> it is not possible to make this a simple wrapper because QObject is
> unmovable and reference counted. That is, QObject is the equivalent of
> (for example) Owned<DeviceState>.
>
>> These 2 methods are the clone, but it seems they're actually similar to
>> Owned<>, i.e., increase refcnt when Rust side wants to "own" or ensure
>> to use this safely.
>>
>> However, there indeed isn't a non-object version of Owned for now, so I
>> think this kind of clone should be okay. Hmm, for long-term, is it
>> valuable to consider a more generic Owned<>?
>
> Linux has ARef<> I think. But it seems overkill for now.
>
>>> +impl<A> FromIterator<A> for QObject
>>> +where
>>> + Self: From<A>,
>>> +{
>>> + fn from_iter<I: IntoIterator<Item = A>>(it: I) -> Self {
>>
>> nit: maybe the name "iter" is better than "it"?
>
> Sure.
>
>>> + match qnum__.kind {
>>> + $($crate::bindings::QNUM_I64 => break {
>>> + let $i64var = unsafe { qnum__.u.i64_ };
>>> + $i64
>>> + },)?
>>> + $($crate::bindings::QNUM_U64 => break {
>>> + let $u64var = unsafe { qnum__.u.u64_ };
>>> + $u64
>>> + },)?
>>> + $($crate::bindings::QNUM_DOUBLE => break {
>>> + let $f64var = unsafe { qnum__.u.dbl };
>>> + $f64
>>> + },)?
>>> + _ => {}
>>
>> I think this doesn't handle a special case: qobj's QNUM type doesn't
>> macth the value type, for example, qobj is QNUM_U64 but value is i64.
>>
>> Though external code won't use this macro, I think panic may be better
>> than {}?> Thurther, there're 2 match blocks. Could we merge them as one?
Just one thing: it's not returning {}, it's returning the value
expressed in $(_ => $other:expr,)?. So I think it's better to keep it
this way.
Paolo
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 03/14] subprojects: add serde
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (13 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 02/14] rust: add basic QObject bindings Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-12-04 14:20 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 04/14] rust: add Serialize implementation for QObject Paolo Bonzini
` (10 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/Cargo.toml | 2 ++
rust/meson.build | 2 ++
scripts/archive-source.sh | 3 ++
scripts/make-release | 2 +-
subprojects/.gitignore | 3 ++
.../packagefiles/serde-1-rs/meson.build | 36 +++++++++++++++++++
.../packagefiles/serde-1.0.226-include.patch | 16 +++++++++
.../packagefiles/serde_core-1-rs/meson.build | 25 +++++++++++++
.../serde_core-1.0.226-include.patch | 15 ++++++++
.../serde_derive-1-rs/meson.build | 35 ++++++++++++++++++
.../serde_derive-1.0.226-include.patch | 11 ++++++
subprojects/serde-1-rs.wrap | 11 ++++++
subprojects/serde_core-1-rs.wrap | 11 ++++++
subprojects/serde_derive-1-rs.wrap | 11 ++++++
14 files changed, 182 insertions(+), 1 deletion(-)
create mode 100644 subprojects/packagefiles/serde-1-rs/meson.build
create mode 100644 subprojects/packagefiles/serde-1.0.226-include.patch
create mode 100644 subprojects/packagefiles/serde_core-1-rs/meson.build
create mode 100644 subprojects/packagefiles/serde_core-1.0.226-include.patch
create mode 100644 subprojects/packagefiles/serde_derive-1-rs/meson.build
create mode 100644 subprojects/packagefiles/serde_derive-1.0.226-include.patch
create mode 100644 subprojects/serde-1-rs.wrap
create mode 100644 subprojects/serde_core-1-rs.wrap
create mode 100644 subprojects/serde_derive-1-rs.wrap
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 783e626802c..a512fb142e2 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -30,6 +30,8 @@ anyhow = "~1.0"
foreign = "~0.3.1"
libc = "0.2.162"
glib-sys = { version = "0.21.2", features = ["v2_66"] }
+serde = "1.0.226"
+serde_derive = "1.0.226"
[workspace.lints.rust]
unexpected_cfgs = { level = "deny", check-cfg = ['cfg(MESON)'] }
diff --git a/rust/meson.build b/rust/meson.build
index 76e10699b37..fd2ca40ef90 100644
--- a/rust/meson.build
+++ b/rust/meson.build
@@ -4,6 +4,7 @@ subproject('bilge-impl-0.2-rs', required: true)
subproject('foreign-0.3-rs', required: true)
subproject('glib-sys-0.21-rs', required: true)
subproject('libc-0.2-rs', required: true)
+subproject('serde-1-rs', required: true)
anyhow_rs = dependency('anyhow-1-rs')
bilge_rs = dependency('bilge-0.2-rs')
@@ -11,6 +12,7 @@ bilge_impl_rs = dependency('bilge-impl-0.2-rs')
foreign_rs = dependency('foreign-0.3-rs')
glib_sys_rs = dependency('glib-sys-0.21-rs')
libc_rs = dependency('libc-0.2-rs')
+serde_rs = dependency('serde-1-rs')
subproject('proc-macro2-1-rs', required: true)
subproject('quote-1-rs', required: true)
diff --git a/scripts/archive-source.sh b/scripts/archive-source.sh
index 8f97b19a088..3ed0429d806 100755
--- a/scripts/archive-source.sh
+++ b/scripts/archive-source.sh
@@ -45,6 +45,9 @@ subprojects=(
proc-macro-error-attr-1-rs
proc-macro2-1-rs
quote-1-rs
+ serde-1-rs
+ serde_core-1-rs
+ serde_derive-1-rs
syn-2-rs
unicode-ident-1-rs
)
diff --git a/scripts/make-release b/scripts/make-release
index bc1b43caa25..eb5808b83ec 100755
--- a/scripts/make-release
+++ b/scripts/make-release
@@ -44,7 +44,7 @@ SUBPROJECTS="libvfio-user keycodemapdb berkeley-softfloat-3
bilge-impl-0.2-rs either-1-rs foreign-0.3-rs itertools-0.11-rs
libc-0.2-rs proc-macro2-1-rs
proc-macro-error-1-rs proc-macro-error-attr-1-rs quote-1-rs
- syn-2-rs unicode-ident-1-rs"
+ serde-1-rs serde_core-1-rs serde_derive-1-rs syn-2-rs unicode-ident-1-rs"
src="$1"
version="$2"
diff --git a/subprojects/.gitignore b/subprojects/.gitignore
index c00c8478372..697d1ef3bdb 100644
--- a/subprojects/.gitignore
+++ b/subprojects/.gitignore
@@ -20,6 +20,9 @@
/proc-macro-error-attr-*
/proc-macro*
/quote-*
+/serde-*
+/serde_core-*
+/serde_derive-*
/syn-*
/unicode-ident-*
diff --git a/subprojects/packagefiles/serde-1-rs/meson.build b/subprojects/packagefiles/serde-1-rs/meson.build
new file mode 100644
index 00000000000..6cb2b59a147
--- /dev/null
+++ b/subprojects/packagefiles/serde-1-rs/meson.build
@@ -0,0 +1,36 @@
+project('serde-1-rs', 'rust',
+ meson_version: '>=1.5.0',
+ version: '1.0.226',
+ license: 'MIT OR Apache-2.0',
+ default_options: [])
+
+subproject('serde_core-1-rs', required: true)
+subproject('serde_derive-1-rs', required: true)
+
+serde_core_dep = dependency('serde_core-1-rs')
+serde_derive_dep = dependency('serde_derive-1-rs')
+
+_serde_rs = static_library(
+ 'serde',
+ files('src/lib.rs'),
+ gnu_symbol_visibility: 'hidden',
+ override_options: ['rust_std=2021', 'build.rust_std=2021'],
+ rust_abi: 'rust',
+ rust_args: [
+ '--cap-lints', 'allow',
+ '--cfg', 'feature="alloc"',
+ '--cfg', 'feature="std"',
+ '--cfg', 'feature="derive"',
+ ],
+ dependencies: [
+ serde_core_dep,
+ serde_derive_dep,
+ ]
+)
+
+serde_dep = declare_dependency(
+ link_with: _serde_rs,
+ dependencies: serde_derive_dep,
+)
+
+meson.override_dependency('serde-1-rs', serde_dep, native: true)
diff --git a/subprojects/packagefiles/serde-1.0.226-include.patch b/subprojects/packagefiles/serde-1.0.226-include.patch
new file mode 100644
index 00000000000..92878136878
--- /dev/null
+++ b/subprojects/packagefiles/serde-1.0.226-include.patch
@@ -0,0 +1,16 @@
+--- a/src/lib.rs 2025-09-23 13:41:09.327582205 +0200
++++ b/src/lib.rs 2025-09-23 13:41:23.043271856 +0200
+@@ -241,7 +241,12 @@
+ #[doc(hidden)]
+ mod private;
+
+-include!(concat!(env!("OUT_DIR"), "/private.rs"));
++#[doc(hidden)]
++pub mod __private_MESON {
++ #[doc(hidden)]
++ pub use crate::private::*;
++}
++use serde_core::__private_MESON as serde_core_private;
+
+ // Re-export #[derive(Serialize, Deserialize)].
+ //
diff --git a/subprojects/packagefiles/serde_core-1-rs/meson.build b/subprojects/packagefiles/serde_core-1-rs/meson.build
new file mode 100644
index 00000000000..e917d9337f6
--- /dev/null
+++ b/subprojects/packagefiles/serde_core-1-rs/meson.build
@@ -0,0 +1,25 @@
+project('serde_core-1-rs', 'rust',
+ meson_version: '>=1.5.0',
+ version: '1.0.226',
+ license: 'MIT OR Apache-2.0',
+ default_options: [])
+
+_serde_core_rs = static_library(
+ 'serde_core',
+ files('src/lib.rs'),
+ gnu_symbol_visibility: 'hidden',
+ override_options: ['rust_std=2021', 'build.rust_std=2021'],
+ rust_abi: 'rust',
+ rust_args: [
+ '--cap-lints', 'allow',
+ '--cfg', 'feature="alloc"',
+ '--cfg', 'feature="result"',
+ '--cfg', 'feature="std"',
+ ],
+)
+
+serde_core_dep = declare_dependency(
+ link_with: _serde_core_rs,
+)
+
+meson.override_dependency('serde_core-1-rs', serde_core_dep, native: true)
diff --git a/subprojects/packagefiles/serde_core-1.0.226-include.patch b/subprojects/packagefiles/serde_core-1.0.226-include.patch
new file mode 100644
index 00000000000..d1321dfe272
--- /dev/null
+++ b/subprojects/packagefiles/serde_core-1.0.226-include.patch
@@ -0,0 +1,15 @@
+--- a/src/lib.rs 2025-09-23 13:32:40.872421170 +0200
++++ b/src/lib.rs 2025-09-23 13:32:52.181098856 +0200
+@@ -263,7 +263,11 @@
+ pub use core::result::Result;
+ }
+
+-include!(concat!(env!("OUT_DIR"), "/private.rs"));
++#[doc(hidden)]
++pub mod __private_MESON {
++ #[doc(hidden)]
++ pub use crate::private::*;
++}
+
+ #[cfg(all(not(feature = "std"), no_core_error))]
+ mod std_error;
diff --git a/subprojects/packagefiles/serde_derive-1-rs/meson.build b/subprojects/packagefiles/serde_derive-1-rs/meson.build
new file mode 100644
index 00000000000..6c1001a844a
--- /dev/null
+++ b/subprojects/packagefiles/serde_derive-1-rs/meson.build
@@ -0,0 +1,35 @@
+project('serde_derive-1-rs', 'rust',
+ meson_version: '>=1.5.0',
+ version: '1.0.226',
+ license: 'MIT OR Apache-2.0',
+ default_options: [])
+
+subproject('quote-1-rs', required: true)
+subproject('syn-2-rs', required: true)
+subproject('proc-macro2-1-rs', required: true)
+
+quote_dep = dependency('quote-1-rs', native: true)
+syn_dep = dependency('syn-2-rs', native: true)
+proc_macro2_dep = dependency('proc-macro2-1-rs', native: true)
+
+rust = import('rust')
+
+_serde_derive_rs = rust.proc_macro(
+ 'serde_derive',
+ files('src/lib.rs'),
+ override_options: ['rust_std=2021', 'build.rust_std=2021'],
+ rust_args: [
+ '--cap-lints', 'allow',
+ ],
+ dependencies: [
+ quote_dep,
+ syn_dep,
+ proc_macro2_dep,
+ ],
+)
+
+serde_derive_dep = declare_dependency(
+ link_with: _serde_derive_rs,
+)
+
+meson.override_dependency('serde_derive-1-rs', serde_derive_dep)
diff --git a/subprojects/packagefiles/serde_derive-1.0.226-include.patch b/subprojects/packagefiles/serde_derive-1.0.226-include.patch
new file mode 100644
index 00000000000..81d65564d29
--- /dev/null
+++ b/subprojects/packagefiles/serde_derive-1.0.226-include.patch
@@ -0,0 +1,11 @@
+--- a/src/lib.rs 2025-09-23 13:51:51.540191923 +0200
++++ b/src/lib.rs 2025-09-23 13:52:07.690060195 +0200
+@@ -98,7 +98,7 @@
+ impl private {
+ fn ident(&self) -> Ident {
+ Ident::new(
+- concat!("__private", env!("CARGO_PKG_VERSION_PATCH")),
++ "__private_MESON",
+ Span::call_site(),
+ )
+ }
diff --git a/subprojects/serde-1-rs.wrap b/subprojects/serde-1-rs.wrap
new file mode 100644
index 00000000000..56746dd0f43
--- /dev/null
+++ b/subprojects/serde-1-rs.wrap
@@ -0,0 +1,11 @@
+[wrap-file]
+directory = serde-1.0.226
+source_url = https://crates.io/api/v1/crates/serde/1.0.226/download
+source_filename = serde-1.0.226.0.tar.gz
+source_hash = 0dca6411025b24b60bfa7ec1fe1f8e710ac09782dca409ee8237ba74b51295fd
+#method = cargo
+diff_files = serde-1.0.226-include.patch
+patch_directory = serde-1-rs
+
+# bump this version number on every change to meson.build or the patches:
+# v1
diff --git a/subprojects/serde_core-1-rs.wrap b/subprojects/serde_core-1-rs.wrap
new file mode 100644
index 00000000000..3692e754935
--- /dev/null
+++ b/subprojects/serde_core-1-rs.wrap
@@ -0,0 +1,11 @@
+[wrap-file]
+directory = serde_core-1.0.226
+source_url = https://crates.io/api/v1/crates/serde_core/1.0.226/download
+source_filename = serde_core-1.0.226.0.tar.gz
+source_hash = ba2ba63999edb9dac981fb34b3e5c0d111a69b0924e253ed29d83f7c99e966a4
+#method = cargo
+diff_files = serde_core-1.0.226-include.patch
+patch_directory = serde_core-1-rs
+
+# bump this version number on every change to meson.build or the patches:
+# v1
diff --git a/subprojects/serde_derive-1-rs.wrap b/subprojects/serde_derive-1-rs.wrap
new file mode 100644
index 00000000000..00c92dc79cf
--- /dev/null
+++ b/subprojects/serde_derive-1-rs.wrap
@@ -0,0 +1,11 @@
+[wrap-file]
+directory = serde_derive-1.0.226
+source_url = https://crates.io/api/v1/crates/serde_derive/1.0.226/download
+source_filename = serde_derive-1.0.226.0.tar.gz
+source_hash = 8db53ae22f34573731bafa1db20f04027b2d25e02d8205921b569171699cdb33
+#method = cargo
+diff_files = serde_derive-1.0.226-include.patch
+patch_directory = serde_derive-1-rs
+
+# bump this version number on every change to meson.build or the patches:
+# v1
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 03/14] subprojects: add serde
2025-10-01 8:00 ` [PATCH 03/14] subprojects: add serde Paolo Bonzini
@ 2025-12-04 14:20 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-12-04 14:20 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On Wed, Oct 01, 2025 at 10:00:40AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 10:00:40 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 03/14] subprojects: add serde
> X-Mailer: git-send-email 2.51.0
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/Cargo.toml | 2 ++
> rust/meson.build | 2 ++
> scripts/archive-source.sh | 3 ++
> scripts/make-release | 2 +-
> subprojects/.gitignore | 3 ++
> .../packagefiles/serde-1-rs/meson.build | 36 +++++++++++++++++++
> .../packagefiles/serde-1.0.226-include.patch | 16 +++++++++
> .../packagefiles/serde_core-1-rs/meson.build | 25 +++++++++++++
> .../serde_core-1.0.226-include.patch | 15 ++++++++
> .../serde_derive-1-rs/meson.build | 35 ++++++++++++++++++
> .../serde_derive-1.0.226-include.patch | 11 ++++++
> subprojects/serde-1-rs.wrap | 11 ++++++
> subprojects/serde_core-1-rs.wrap | 11 ++++++
> subprojects/serde_derive-1-rs.wrap | 11 ++++++
> 14 files changed, 182 insertions(+), 1 deletion(-)
> create mode 100644 subprojects/packagefiles/serde-1-rs/meson.build
> create mode 100644 subprojects/packagefiles/serde-1.0.226-include.patch
> create mode 100644 subprojects/packagefiles/serde_core-1-rs/meson.build
> create mode 100644 subprojects/packagefiles/serde_core-1.0.226-include.patch
> create mode 100644 subprojects/packagefiles/serde_derive-1-rs/meson.build
> create mode 100644 subprojects/packagefiles/serde_derive-1.0.226-include.patch
> create mode 100644 subprojects/serde-1-rs.wrap
> create mode 100644 subprojects/serde_core-1-rs.wrap
> create mode 100644 subprojects/serde_derive-1-rs.wrap
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 04/14] rust: add Serialize implementation for QObject
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (14 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 03/14] subprojects: add serde Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-12-05 7:38 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 05/14] rust: add Serializer (to_qobject) " Paolo Bonzini
` (9 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
This allows QObject to be converted to other formats, for example
JSON via serde_json.
This is not too useful, since QObjects are consumed by
C code or deserialized into structs, but it can be used for testing
and it is part of the full implementation of a serde format.
Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/Cargo.lock | 1 +
rust/util/Cargo.toml | 1 +
rust/util/meson.build | 3 +-
rust/util/src/qobject/mod.rs | 4 +-
rust/util/src/qobject/serialize.rs | 59 ++++++++++++++++++++++++++++++
5 files changed, 65 insertions(+), 3 deletions(-)
create mode 100644 rust/util/src/qobject/serialize.rs
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 0c1df625df1..c1075e11d6c 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -446,6 +446,7 @@ dependencies = [
"foreign",
"glib-sys",
"libc",
+ "serde",
]
[[package]]
diff --git a/rust/util/Cargo.toml b/rust/util/Cargo.toml
index 85f91436545..554004816eb 100644
--- a/rust/util/Cargo.toml
+++ b/rust/util/Cargo.toml
@@ -17,6 +17,7 @@ anyhow = { workspace = true }
foreign = { workspace = true }
glib-sys = { workspace = true }
libc = { workspace = true }
+serde = { workspace = true }
common = { path = "../common" }
[lints]
diff --git a/rust/util/meson.build b/rust/util/meson.build
index 38da1ba8cd1..5b99d38c903 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -39,10 +39,11 @@ _util_rs = static_library(
{'.': _util_bindings_inc_rs,
'qobject': [
'src/qobject/mod.rs',
+ 'src/qobject/serialize.rs',
]}),
override_options: ['rust_std=2021', 'build.rust_std=2021'],
rust_abi: 'rust',
- dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs, qom, qemuutil],
+ dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs, serde_rs, qom, qemuutil],
)
util_rs = declare_dependency(link_with: [_util_rs], dependencies: [qemuutil, qom])
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index f43d87a3b66..2e3cb247b27 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -6,6 +6,8 @@
#![deny(clippy::unwrap_used)]
+mod serialize;
+
use std::{
cell::UnsafeCell,
ffi::{c_char, CString},
@@ -222,7 +224,6 @@ fn drop(&mut self) {
}
}
-#[allow(unused)]
macro_rules! match_qobject {
(@internal ($qobj:expr) =>
$(() => $unit:expr,)?
@@ -305,5 +306,4 @@ macro_rules! match_qobject {
$($type $(($val))? => $code,)+)
};
}
-#[allow(unused_imports)]
use match_qobject;
diff --git a/rust/util/src/qobject/serialize.rs b/rust/util/src/qobject/serialize.rs
new file mode 100644
index 00000000000..34ec3847c1d
--- /dev/null
+++ b/rust/util/src/qobject/serialize.rs
@@ -0,0 +1,59 @@
+//! `QObject` serialization
+//!
+//! This module implements the [`Serialize`] trait for `QObject`,
+//! allowing it to be converted to other formats, for example
+//! JSON.
+
+use std::{ffi::CStr, mem::ManuallyDrop, ptr::addr_of};
+
+use serde::ser::{self, Serialize, SerializeMap, SerializeSeq};
+
+use super::{match_qobject, QObject};
+use crate::bindings;
+
+impl Serialize for QObject {
+ #[inline]
+ fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ where
+ S: ::serde::Serializer,
+ {
+ match_qobject! { (self) =>
+ () => serializer.serialize_unit(),
+ bool(b) => serializer.serialize_bool(b),
+ i64(i) => serializer.serialize_i64(i),
+ u64(u) => serializer.serialize_u64(u),
+ f64(f) => serializer.serialize_f64(f),
+ CStr(cstr) => cstr.to_str().map_or_else(
+ |_| Err(ser::Error::custom("invalid UTF-8 in QString")),
+ |s| serializer.serialize_str(s),
+ ),
+ QList(l) => {
+ let mut node_ptr = unsafe { l.head.tqh_first };
+ let mut state = serializer.serialize_seq(None)?;
+ while !node_ptr.is_null() {
+ let node = unsafe { &*node_ptr };
+ let elem = unsafe { ManuallyDrop::new(QObject::from_raw(addr_of!(*node.value))) };
+ state.serialize_element(&*elem)?;
+ node_ptr = unsafe { node.next.tqe_next };
+ }
+ state.end()
+ },
+ QDict(d) => {
+ let mut state = serializer.serialize_map(Some(d.size))?;
+ let mut e_ptr = unsafe { bindings::qdict_first(d) };
+ while !e_ptr.is_null() {
+ let e = unsafe { &*e_ptr };
+ let key = unsafe { CStr::from_ptr(e.key) };
+ key.to_str().map_or_else(
+ |_| Err(ser::Error::custom("invalid UTF-8 in key")),
+ |k| state.serialize_key(k),
+ )?;
+ let value = unsafe { ManuallyDrop::new(QObject::from_raw(addr_of!(*e.value))) };
+ state.serialize_value(&*value)?;
+ e_ptr = unsafe { bindings::qdict_next(d, e) };
+ }
+ state.end()
+ }
+ }
+ }
+}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 04/14] rust: add Serialize implementation for QObject
2025-10-01 8:00 ` [PATCH 04/14] rust: add Serialize implementation for QObject Paolo Bonzini
@ 2025-12-05 7:38 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-12-05 7:38 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On Wed, Oct 01, 2025 at 10:00:41AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 10:00:41 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 04/14] rust: add Serialize implementation for QObject
> X-Mailer: git-send-email 2.51.0
>
> This allows QObject to be converted to other formats, for example
> JSON via serde_json.
>
> This is not too useful, since QObjects are consumed by
> C code or deserialized into structs, but it can be used for testing
> and it is part of the full implementation of a serde format.
>
> Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/Cargo.lock | 1 +
> rust/util/Cargo.toml | 1 +
> rust/util/meson.build | 3 +-
> rust/util/src/qobject/mod.rs | 4 +-
> rust/util/src/qobject/serialize.rs | 59 ++++++++++++++++++++++++++++++
> 5 files changed, 65 insertions(+), 3 deletions(-)
> create mode 100644 rust/util/src/qobject/serialize.rs
...
> +impl Serialize for QObject {
> + #[inline]
> + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
> + where
> + S: ::serde::Serializer,
> + {
> + match_qobject! { (self) =>
> + () => serializer.serialize_unit(),
> + bool(b) => serializer.serialize_bool(b),
> + i64(i) => serializer.serialize_i64(i),
> + u64(u) => serializer.serialize_u64(u),
> + f64(f) => serializer.serialize_f64(f),
> + CStr(cstr) => cstr.to_str().map_or_else(
> + |_| Err(ser::Error::custom("invalid UTF-8 in QString")),
> + |s| serializer.serialize_str(s),
> + ),
> + QList(l) => {
> + let mut node_ptr = unsafe { l.head.tqh_first };
> + let mut state = serializer.serialize_seq(None)?;
> + while !node_ptr.is_null() {
> + let node = unsafe { &*node_ptr };
> + let elem = unsafe { ManuallyDrop::new(QObject::from_raw(addr_of!(*node.value))) };
> + state.serialize_element(&*elem)?;
QObject here is always valid so it's not necessary to concern about it
is destroied by C side, and so that it's not necessary to use
cloned_from_raw here.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 05/14] rust: add Serializer (to_qobject) implementation for QObject
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (15 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 04/14] rust: add Serialize implementation for QObject Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-12-05 9:13 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 06/14] rust: add Deserialize " Paolo Bonzini
` (8 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
This allows creating QObject from any serializable data structure.
Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/util/meson.build | 2 +
rust/util/src/qobject/error.rs | 52 +++
rust/util/src/qobject/mod.rs | 4 +
rust/util/src/qobject/serializer.rs | 585 ++++++++++++++++++++++++++++
4 files changed, 643 insertions(+)
create mode 100644 rust/util/src/qobject/error.rs
create mode 100644 rust/util/src/qobject/serializer.rs
diff --git a/rust/util/meson.build b/rust/util/meson.build
index 5b99d38c903..fb152766003 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -39,6 +39,8 @@ _util_rs = static_library(
{'.': _util_bindings_inc_rs,
'qobject': [
'src/qobject/mod.rs',
+ 'src/qobject/error.rs',
+ 'src/qobject/serializer.rs',
'src/qobject/serialize.rs',
]}),
override_options: ['rust_std=2021', 'build.rust_std=2021'],
diff --git a/rust/util/src/qobject/error.rs b/rust/util/src/qobject/error.rs
new file mode 100644
index 00000000000..5212e65c4f7
--- /dev/null
+++ b/rust/util/src/qobject/error.rs
@@ -0,0 +1,52 @@
+//! Error data type for `QObject`'s `serde` integration
+
+use std::{
+ ffi::NulError,
+ fmt::{self, Display},
+ str::Utf8Error,
+};
+
+use serde::ser;
+
+#[derive(Debug)]
+pub enum Error {
+ Custom(String),
+ KeyMustBeAString,
+ InvalidUtf8,
+ NulEncountered,
+ NumberOutOfRange,
+}
+
+impl ser::Error for Error {
+ fn custom<T: Display>(msg: T) -> Self {
+ Error::Custom(msg.to_string())
+ }
+}
+
+impl From<NulError> for Error {
+ fn from(_: NulError) -> Self {
+ Error::NulEncountered
+ }
+}
+
+impl From<Utf8Error> for Error {
+ fn from(_: Utf8Error) -> Self {
+ Error::InvalidUtf8
+ }
+}
+
+impl Display for Error {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Error::Custom(msg) => formatter.write_str(msg),
+ Error::KeyMustBeAString => formatter.write_str("key must be a string"),
+ Error::InvalidUtf8 => formatter.write_str("invalid UTF-8 in string"),
+ Error::NulEncountered => formatter.write_str("NUL character in string"),
+ Error::NumberOutOfRange => formatter.write_str("number out of range"),
+ }
+ }
+}
+
+impl std::error::Error for Error {}
+
+pub type Result<T> = std::result::Result<T, Error>;
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index 2e3cb247b27..cd034185748 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -6,7 +6,9 @@
#![deny(clippy::unwrap_used)]
+mod error;
mod serialize;
+mod serializer;
use std::{
cell::UnsafeCell,
@@ -17,6 +19,8 @@
};
use common::assert_field_type;
+pub use error::{Error, Result};
+pub use serializer::to_qobject;
use crate::bindings;
diff --git a/rust/util/src/qobject/serializer.rs b/rust/util/src/qobject/serializer.rs
new file mode 100644
index 00000000000..59200683f5d
--- /dev/null
+++ b/rust/util/src/qobject/serializer.rs
@@ -0,0 +1,585 @@
+//! `QObject` serializer
+//!
+//! This module implements a [`Serializer`](serde::ser::Serializer) that
+//! produces `QObject`s, allowing them to be created from serializable data
+//! structures (such as primitive data types, or structs that implement
+//! `Serialize`).
+
+use std::ffi::CString;
+
+use serde::ser::{Impossible, Serialize};
+
+use super::{
+ error::{Error, Result},
+ QObject,
+};
+
+pub struct SerializeTupleVariant {
+ name: CString,
+ vec: Vec<QObject>,
+}
+
+impl serde::ser::SerializeTupleVariant for SerializeTupleVariant {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ self.vec.push(to_qobject(value)?);
+ Ok(())
+ }
+
+ fn end(self) -> Result<QObject> {
+ let SerializeTupleVariant { name, vec, .. } = self;
+
+ // TODO: insert elements one at a time
+ let list = QObject::from_iter(vec);
+
+ // serde by default represents enums as a single-entry object, with
+ // the variant stored in the key ("external tagging"). Internal tagging
+ // is implemented by the struct that requests it, not by the serializer.
+ let map = [(name, list)];
+ Ok(QObject::from_iter(map))
+ }
+}
+
+pub struct SerializeStructVariant {
+ name: CString,
+ vec: Vec<(CString, QObject)>,
+}
+
+impl serde::ser::SerializeStructVariant for SerializeStructVariant {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ self.vec.push((CString::new(key)?, to_qobject(value)?));
+ Ok(())
+ }
+
+ fn end(self) -> Result<QObject> {
+ // TODO: insert keys one at a time
+ let SerializeStructVariant { name, vec, .. } = self;
+ let list = QObject::from_iter(vec);
+
+ // serde by default represents enums as a single-entry object, with
+ // the variant stored in the key ("external tagging"). Internal tagging
+ // is implemented by the struct that requests it, not by the serializer.
+ let map = [(name, list)];
+ Ok(QObject::from_iter(map))
+ }
+}
+
+pub struct SerializeVec {
+ vec: Vec<QObject>,
+}
+
+impl serde::ser::SerializeSeq for SerializeVec {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ self.vec.push(to_qobject(value)?);
+ Ok(())
+ }
+
+ fn end(self) -> Result<QObject> {
+ // TODO: insert elements one at a time
+ let SerializeVec { vec, .. } = self;
+ let list = QObject::from_iter(vec);
+ Ok(list)
+ }
+}
+
+impl serde::ser::SerializeTuple for SerializeVec {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ serde::ser::SerializeSeq::serialize_element(self, value)
+ }
+
+ fn end(self) -> Result<QObject> {
+ serde::ser::SerializeSeq::end(self)
+ }
+}
+
+impl serde::ser::SerializeTupleStruct for SerializeVec {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ serde::ser::SerializeSeq::serialize_element(self, value)
+ }
+
+ fn end(self) -> Result<QObject> {
+ serde::ser::SerializeSeq::end(self)
+ }
+}
+
+struct MapKeySerializer;
+
+impl serde::Serializer for MapKeySerializer {
+ type Ok = CString;
+ type Error = Error;
+
+ type SerializeSeq = Impossible<CString, Error>;
+ type SerializeTuple = Impossible<CString, Error>;
+ type SerializeTupleStruct = Impossible<CString, Error>;
+ type SerializeTupleVariant = Impossible<CString, Error>;
+ type SerializeMap = Impossible<CString, Error>;
+ type SerializeStruct = Impossible<CString, Error>;
+ type SerializeStructVariant = Impossible<CString, Error>;
+
+ #[inline]
+ fn serialize_unit_variant(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ variant: &'static str,
+ ) -> Result<CString> {
+ Ok(CString::new(variant)?)
+ }
+
+ #[inline]
+ fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> Result<CString>
+ where
+ T: ?Sized + Serialize,
+ {
+ value.serialize(self)
+ }
+
+ fn serialize_bool(self, _value: bool) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_i8(self, _value: i8) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_i16(self, _value: i16) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_i32(self, _value: i32) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_i64(self, _value: i64) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_i128(self, _value: i128) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_u8(self, _value: u8) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_u16(self, _value: u16) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_u32(self, _value: u32) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_u64(self, _value: u64) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_u128(self, _value: u128) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_f32(self, _value: f32) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_f64(self, _value: f64) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ #[inline]
+ fn serialize_char(self, _value: char) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ #[inline]
+ fn serialize_str(self, value: &str) -> Result<CString> {
+ Ok(CString::new(value)?)
+ }
+
+ fn serialize_bytes(self, value: &[u8]) -> Result<CString> {
+ Ok(CString::new(value)?)
+ }
+
+ fn serialize_unit(self) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_unit_struct(self, _name: &'static str) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_newtype_variant<T>(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ _variant: &'static str,
+ _value: &T,
+ ) -> Result<CString>
+ where
+ T: ?Sized + Serialize,
+ {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_none(self) -> Result<CString> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_some<T>(self, _value: &T) -> Result<CString>
+ where
+ T: ?Sized + Serialize,
+ {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_tuple_struct(
+ self,
+ _name: &'static str,
+ _len: usize,
+ ) -> Result<Self::SerializeTupleStruct> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_tuple_variant(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ _variant: &'static str,
+ _len: usize,
+ ) -> Result<Self::SerializeTupleVariant> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
+ Err(Error::KeyMustBeAString)
+ }
+
+ fn serialize_struct_variant(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ _variant: &'static str,
+ _len: usize,
+ ) -> Result<Self::SerializeStructVariant> {
+ Err(Error::KeyMustBeAString)
+ }
+}
+
+pub struct SerializeMap {
+ vec: Vec<(CString, QObject)>,
+ next_key: Option<CString>,
+}
+
+impl serde::ser::SerializeMap for SerializeMap {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_key<T>(&mut self, key: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ self.next_key = Some(key.serialize(MapKeySerializer)?);
+ Ok(())
+ }
+
+ fn serialize_value<T>(&mut self, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ let key = self.next_key.take();
+ // Panic because this indicates a bug in the program rather than an
+ // expected failure.
+ let key = key.expect("serialize_value called before serialize_key");
+ self.vec.push((key, to_qobject(value)?));
+ Ok(())
+ }
+
+ fn end(self) -> Result<QObject> {
+ // TODO: insert keys one at a time
+ let SerializeMap { vec, .. } = self;
+ Ok(QObject::from_iter(vec))
+ }
+}
+
+impl serde::ser::SerializeStruct for SerializeMap {
+ type Ok = QObject;
+ type Error = Error;
+
+ fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+ where
+ T: ?Sized + Serialize,
+ {
+ serde::ser::SerializeMap::serialize_entry(self, key, value)
+ }
+
+ fn end(self) -> Result<QObject> {
+ serde::ser::SerializeMap::end(self)
+ }
+}
+
+/// Serializer whose output is a `QObject`.
+///
+/// This is the serializer that backs [`to_qobject`].
+pub struct Serializer;
+
+impl serde::Serializer for Serializer {
+ type Ok = QObject;
+ type Error = Error;
+ type SerializeSeq = SerializeVec;
+ type SerializeTuple = SerializeVec;
+ type SerializeTupleStruct = SerializeVec;
+ type SerializeTupleVariant = SerializeTupleVariant;
+ type SerializeMap = SerializeMap;
+ type SerializeStruct = SerializeMap;
+ type SerializeStructVariant = SerializeStructVariant;
+
+ #[inline]
+ fn serialize_bool(self, value: bool) -> Result<QObject> {
+ Ok(value.into())
+ }
+
+ #[inline]
+ fn serialize_i8(self, value: i8) -> Result<QObject> {
+ self.serialize_i64(i64::from(value))
+ }
+
+ #[inline]
+ fn serialize_i16(self, value: i16) -> Result<QObject> {
+ self.serialize_i64(i64::from(value))
+ }
+
+ #[inline]
+ fn serialize_i32(self, value: i32) -> Result<QObject> {
+ self.serialize_i64(i64::from(value))
+ }
+
+ fn serialize_i64(self, value: i64) -> Result<QObject> {
+ Ok(value.into())
+ }
+
+ fn serialize_i128(self, value: i128) -> Result<QObject> {
+ if let Ok(value) = u64::try_from(value) {
+ Ok(value.into())
+ } else if let Ok(value) = i64::try_from(value) {
+ Ok(value.into())
+ } else {
+ Err(Error::NumberOutOfRange)
+ }
+ }
+
+ #[inline]
+ fn serialize_u8(self, value: u8) -> Result<QObject> {
+ self.serialize_u64(u64::from(value))
+ }
+
+ #[inline]
+ fn serialize_u16(self, value: u16) -> Result<QObject> {
+ self.serialize_u64(u64::from(value))
+ }
+
+ #[inline]
+ fn serialize_u32(self, value: u32) -> Result<QObject> {
+ self.serialize_u64(u64::from(value))
+ }
+
+ #[inline]
+ fn serialize_u64(self, value: u64) -> Result<QObject> {
+ Ok(value.into())
+ }
+
+ fn serialize_u128(self, value: u128) -> Result<QObject> {
+ if let Ok(value) = u64::try_from(value) {
+ Ok(value.into())
+ } else {
+ Err(Error::NumberOutOfRange)
+ }
+ }
+
+ #[inline]
+ fn serialize_f32(self, float: f32) -> Result<QObject> {
+ self.serialize_f64(f64::from(float))
+ }
+
+ #[inline]
+ fn serialize_f64(self, float: f64) -> Result<QObject> {
+ Ok(float.into())
+ }
+
+ #[inline]
+ fn serialize_char(self, value: char) -> Result<QObject> {
+ let mut s = String::new();
+ s.push(value);
+ Ok(CString::new(s)?.into())
+ }
+
+ #[inline]
+ fn serialize_str(self, value: &str) -> Result<QObject> {
+ Ok(CString::new(value)?.into())
+ }
+
+ fn serialize_bytes(self, value: &[u8]) -> Result<QObject> {
+ // Serialize into a vector of numeric QObjects
+ let it = value.iter().map(|&b| u64::from(b));
+ Ok(QObject::from_iter(it))
+ }
+
+ #[inline]
+ fn serialize_unit(self) -> Result<QObject> {
+ Ok(().into())
+ }
+
+ #[inline]
+ fn serialize_unit_struct(self, _name: &'static str) -> Result<QObject> {
+ self.serialize_unit()
+ }
+
+ #[inline]
+ fn serialize_unit_variant(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ variant: &'static str,
+ ) -> Result<QObject> {
+ self.serialize_str(variant)
+ }
+
+ #[inline]
+ fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> Result<QObject>
+ where
+ T: ?Sized + Serialize,
+ {
+ value.serialize(self)
+ }
+
+ fn serialize_newtype_variant<T>(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ variant: &'static str,
+ value: &T,
+ ) -> Result<QObject>
+ where
+ T: ?Sized + Serialize,
+ {
+ // serde by default represents enums as a single-entry object, with
+ // the variant stored in the key ("external tagging"). Internal tagging
+ // is implemented by the struct that requests it, not by the serializer.
+ let map = [(CString::new(variant)?, to_qobject(value)?)];
+ Ok(QObject::from_iter(map))
+ }
+
+ #[inline]
+ fn serialize_none(self) -> Result<QObject> {
+ self.serialize_unit()
+ }
+
+ #[inline]
+ fn serialize_some<T>(self, value: &T) -> Result<QObject>
+ where
+ T: ?Sized + Serialize,
+ {
+ value.serialize(self)
+ }
+
+ fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
+ Ok(SerializeVec {
+ vec: Vec::with_capacity(len.unwrap_or(0)),
+ })
+ }
+
+ fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple> {
+ self.serialize_seq(Some(len))
+ }
+
+ fn serialize_tuple_struct(
+ self,
+ _name: &'static str,
+ len: usize,
+ ) -> Result<Self::SerializeTupleStruct> {
+ self.serialize_seq(Some(len))
+ }
+
+ fn serialize_tuple_variant(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ variant: &'static str,
+ len: usize,
+ ) -> Result<Self::SerializeTupleVariant> {
+ Ok(SerializeTupleVariant {
+ name: CString::new(variant)?,
+ vec: Vec::with_capacity(len),
+ })
+ }
+
+ fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
+ Ok(SerializeMap {
+ vec: Vec::new(),
+ next_key: None,
+ })
+ }
+ fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
+ self.serialize_map(Some(len))
+ }
+
+ fn serialize_struct_variant(
+ self,
+ _name: &'static str,
+ _variant_index: u32,
+ variant: &'static str,
+ _len: usize,
+ ) -> Result<Self::SerializeStructVariant> {
+ Ok(SerializeStructVariant {
+ name: CString::new(variant)?,
+ vec: Vec::new(),
+ })
+ }
+}
+
+pub fn to_qobject<T>(input: T) -> Result<QObject>
+where
+ T: Serialize,
+{
+ input.serialize(Serializer)
+}
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 05/14] rust: add Serializer (to_qobject) implementation for QObject
2025-10-01 8:00 ` [PATCH 05/14] rust: add Serializer (to_qobject) " Paolo Bonzini
@ 2025-12-05 9:13 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-12-05 9:13 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On Wed, Oct 01, 2025 at 10:00:42AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 10:00:42 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 05/14] rust: add Serializer (to_qobject) implementation for
> QObject
> X-Mailer: git-send-email 2.51.0
>
> This allows creating QObject from any serializable data structure.
>
> Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/util/meson.build | 2 +
> rust/util/src/qobject/error.rs | 52 +++
> rust/util/src/qobject/mod.rs | 4 +
> rust/util/src/qobject/serializer.rs | 585 ++++++++++++++++++++++++++++
> 4 files changed, 643 insertions(+)
> create mode 100644 rust/util/src/qobject/error.rs
> create mode 100644 rust/util/src/qobject/serializer.rs
Good implementation,
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 06/14] rust: add Deserialize implementation for QObject
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (16 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 05/14] rust: add Serializer (to_qobject) " Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-12-05 9:54 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 07/14] rust: add Deserializer (from_qobject) " Paolo Bonzini
` (7 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
This allows QObject to be created from any serializable format, for
example JSON via serde_json.
This is not too useful, since QObjects are produced by
C code or by serializing structs, but it can be used for testing
and it is part of the full implementation of a serde format.
Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/util/meson.build | 1 +
rust/util/src/qobject/deserialize.rs | 134 +++++++++++++++++++++++++++
rust/util/src/qobject/mod.rs | 1 +
3 files changed, 136 insertions(+)
create mode 100644 rust/util/src/qobject/deserialize.rs
diff --git a/rust/util/meson.build b/rust/util/meson.build
index fb152766003..2b72af99dd5 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -39,6 +39,7 @@ _util_rs = static_library(
{'.': _util_bindings_inc_rs,
'qobject': [
'src/qobject/mod.rs',
+ 'src/qobject/deserialize.rs',
'src/qobject/error.rs',
'src/qobject/serializer.rs',
'src/qobject/serialize.rs',
diff --git a/rust/util/src/qobject/deserialize.rs b/rust/util/src/qobject/deserialize.rs
new file mode 100644
index 00000000000..280a577b6be
--- /dev/null
+++ b/rust/util/src/qobject/deserialize.rs
@@ -0,0 +1,134 @@
+//! `QObject` deserialization
+//!
+//! This module implements the [`Deserialize`] trait for `QObject`,
+//! allowing it to be created from any serializable format, for
+//! example JSON.
+
+use core::fmt;
+use std::ffi::CString;
+
+use serde::de::{self, Deserialize, MapAccess, SeqAccess, Visitor};
+
+use super::{to_qobject, QObject};
+
+impl<'de> Deserialize<'de> for QObject {
+ #[inline]
+ fn deserialize<D>(deserializer: D) -> Result<QObject, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ struct ValueVisitor;
+
+ impl<'de> Visitor<'de> for ValueVisitor {
+ type Value = QObject;
+
+ fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ formatter.write_str("any valid JSON value")
+ }
+
+ #[inline]
+ fn visit_bool<E>(self, value: bool) -> Result<QObject, E> {
+ Ok(value.into())
+ }
+
+ #[inline]
+ fn visit_i64<E>(self, value: i64) -> Result<QObject, E> {
+ Ok(value.into())
+ }
+
+ fn visit_i128<E>(self, value: i128) -> Result<QObject, E>
+ where
+ E: serde::de::Error,
+ {
+ to_qobject(value).map_err(|_| de::Error::custom("number out of range"))
+ }
+
+ #[inline]
+ fn visit_u64<E>(self, value: u64) -> Result<QObject, E> {
+ Ok(value.into())
+ }
+
+ fn visit_u128<E>(self, value: u128) -> Result<QObject, E>
+ where
+ E: serde::de::Error,
+ {
+ to_qobject(value).map_err(|_| de::Error::custom("number out of range"))
+ }
+
+ #[inline]
+ fn visit_f64<E>(self, value: f64) -> Result<QObject, E> {
+ Ok(value.into())
+ }
+
+ #[inline]
+ fn visit_str<E>(self, value: &str) -> Result<QObject, E>
+ where
+ E: serde::de::Error,
+ {
+ CString::new(value)
+ .map_err(|_| de::Error::custom("NUL character in string"))
+ .map(QObject::from)
+ }
+
+ #[inline]
+ fn visit_string<E>(self, value: String) -> Result<QObject, E>
+ where
+ E: serde::de::Error,
+ {
+ CString::new(value)
+ .map_err(|_| de::Error::custom("NUL character in string"))
+ .map(QObject::from)
+ }
+
+ #[inline]
+ fn visit_none<E>(self) -> Result<QObject, E> {
+ Ok(().into())
+ }
+
+ #[inline]
+ fn visit_some<D>(self, deserializer: D) -> Result<QObject, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ Deserialize::deserialize(deserializer)
+ }
+
+ #[inline]
+ fn visit_unit<E>(self) -> Result<QObject, E> {
+ Ok(().into())
+ }
+
+ #[inline]
+ fn visit_seq<V>(self, mut visitor: V) -> Result<QObject, V::Error>
+ where
+ V: SeqAccess<'de>,
+ {
+ // TODO: insert elements one at a time
+ let mut vec = Vec::<QObject>::new();
+
+ while let Some(elem) = visitor.next_element()? {
+ vec.push(elem);
+ }
+ Ok(QObject::from_iter(vec))
+ }
+
+ fn visit_map<V>(self, mut visitor: V) -> Result<QObject, V::Error>
+ where
+ V: MapAccess<'de>,
+ {
+ // TODO: insert elements one at a time
+ let mut vec = Vec::<(CString, QObject)>::new();
+
+ if let Some(first_key) = visitor.next_key()? {
+ vec.push((first_key, visitor.next_value()?));
+ while let Some((key, value)) = visitor.next_entry()? {
+ vec.push((key, value));
+ }
+ }
+ Ok(QObject::from_iter(vec))
+ }
+ }
+
+ deserializer.deserialize_any(ValueVisitor)
+ }
+}
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index cd034185748..aec635a5ccc 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -6,6 +6,7 @@
#![deny(clippy::unwrap_used)]
+mod deserialize;
mod error;
mod serialize;
mod serializer;
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 06/14] rust: add Deserialize implementation for QObject
2025-10-01 8:00 ` [PATCH 06/14] rust: add Deserialize " Paolo Bonzini
@ 2025-12-05 9:54 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-12-05 9:54 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On Wed, Oct 01, 2025 at 10:00:43AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 10:00:43 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 06/14] rust: add Deserialize implementation for QObject
> X-Mailer: git-send-email 2.51.0
>
> This allows QObject to be created from any serializable format, for
> example JSON via serde_json.
>
> This is not too useful, since QObjects are produced by
> C code or by serializing structs, but it can be used for testing
> and it is part of the full implementation of a serde format.
>
> Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> rust/util/meson.build | 1 +
> rust/util/src/qobject/deserialize.rs | 134 +++++++++++++++++++++++++++
> rust/util/src/qobject/mod.rs | 1 +
> 3 files changed, 136 insertions(+)
> create mode 100644 rust/util/src/qobject/deserialize.rs
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 07/14] rust: add Deserializer (from_qobject) implementation for QObject
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (17 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 06/14] rust: add Deserialize " Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-12-05 10:16 ` Zhao Liu
2025-10-01 8:00 ` [PATCH 08/14] rust/qobject: add Display/Debug Paolo Bonzini
` (6 subsequent siblings)
25 siblings, 1 reply; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
This allows creating any serializable data structure from QObject.
Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
docs/devel/rust.rst | 1 +
rust/util/meson.build | 1 +
rust/util/src/qobject/deserializer.rs | 373 ++++++++++++++++++++++++++
rust/util/src/qobject/error.rs | 8 +-
rust/util/src/qobject/mod.rs | 2 +
5 files changed, 384 insertions(+), 1 deletion(-)
create mode 100644 rust/util/src/qobject/deserializer.rs
diff --git a/docs/devel/rust.rst b/docs/devel/rust.rst
index 79c26d9d165..c7f3a496a25 100644
--- a/docs/devel/rust.rst
+++ b/docs/devel/rust.rst
@@ -162,6 +162,7 @@ module status
``util::error`` stable
``util::log`` proof of concept
``util::module`` complete
+``util::qobject`` stable
``util::timer`` stable
========================== ======================
diff --git a/rust/util/meson.build b/rust/util/meson.build
index 2b72af99dd5..45366d03786 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -39,6 +39,7 @@ _util_rs = static_library(
{'.': _util_bindings_inc_rs,
'qobject': [
'src/qobject/mod.rs',
+ 'src/qobject/deserializer.rs',
'src/qobject/deserialize.rs',
'src/qobject/error.rs',
'src/qobject/serializer.rs',
diff --git a/rust/util/src/qobject/deserializer.rs b/rust/util/src/qobject/deserializer.rs
new file mode 100644
index 00000000000..a2fe417e72a
--- /dev/null
+++ b/rust/util/src/qobject/deserializer.rs
@@ -0,0 +1,373 @@
+//! `QObject` deserializer
+//!
+//! This module implements a [`Deserializer`](serde::de::Deserializer) that
+//! produces `QObject`s, allowing them to be turned into deserializable data
+//! structures (such as primitive data types, or structs that implement
+//! `Deserialize`).
+
+use std::ffi::CStr;
+
+use serde::de::{
+ self, value::StrDeserializer, DeserializeSeed, Expected, MapAccess, SeqAccess, Unexpected,
+ Visitor,
+};
+
+use super::{
+ error::{Error, Result},
+ match_qobject, QObject,
+};
+use crate::bindings;
+
+impl QObject {
+ #[cold]
+ fn invalid_type<E>(&self, exp: &dyn Expected) -> E
+ where
+ E: serde::de::Error,
+ {
+ serde::de::Error::invalid_type(self.unexpected(), exp)
+ }
+
+ #[cold]
+ fn unexpected(&self) -> Unexpected<'_> {
+ match_qobject! { (self) =>
+ () => Unexpected::Unit,
+ bool(b) => Unexpected::Bool(b),
+ i64(n) => Unexpected::Signed(n),
+ u64(n) => Unexpected::Unsigned(n),
+ f64(n) => Unexpected::Float(n),
+ CStr(s) => s.to_str().map_or_else(
+ |_| Unexpected::Other("string with invalid UTF-8"),
+ Unexpected::Str),
+ QList(_) => Unexpected::Seq,
+ QDict(_) => Unexpected::Map,
+ }
+ }
+}
+
+fn visit_qlist_ref<'de, V>(qlist: &'de bindings::QList, visitor: V) -> Result<V::Value>
+where
+ V: Visitor<'de>,
+{
+ struct QListDeserializer(*mut bindings::QListEntry, usize);
+
+ impl<'de> SeqAccess<'de> for QListDeserializer {
+ type Error = Error;
+
+ fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+ where
+ T: DeserializeSeed<'de>,
+ {
+ if self.0.is_null() {
+ return Ok(None);
+ }
+
+ let e = unsafe { &*self.0 };
+ // increment the reference count because deserialize consumes `value`.
+ let value = unsafe { QObject::cloned_from_raw(e.value.cast_const()) };
+ let result = seed.deserialize(value);
+ self.0 = unsafe { e.next.tqe_next };
+ self.1 += 1;
+ result.map(Some)
+ }
+ }
+
+ let mut deserializer = QListDeserializer(unsafe { qlist.head.tqh_first }, 0);
+ let seq = visitor.visit_seq(&mut deserializer)?;
+ if deserializer.0.is_null() {
+ Ok(seq)
+ } else {
+ Err(serde::de::Error::invalid_length(
+ deserializer.1,
+ &"fewer elements in array",
+ ))
+ }
+}
+
+fn visit_qdict_ref<'de, V>(qdict: &'de bindings::QDict, visitor: V) -> Result<V::Value>
+where
+ V: Visitor<'de>,
+{
+ struct QDictDeserializer(*mut bindings::QDict, *const bindings::QDictEntry);
+
+ impl<'de> MapAccess<'de> for QDictDeserializer {
+ type Error = Error;
+
+ fn next_key_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+ where
+ T: DeserializeSeed<'de>,
+ {
+ if self.1.is_null() {
+ return Ok(None);
+ }
+
+ let e = unsafe { &*self.1 };
+ let key = unsafe { CStr::from_ptr(e.key) };
+ let key_de = StrDeserializer::new(key.to_str()?);
+ seed.deserialize(key_de).map(Some)
+ }
+
+ fn next_value_seed<T>(&mut self, seed: T) -> Result<T::Value>
+ where
+ T: DeserializeSeed<'de>,
+ {
+ if self.1.is_null() {
+ panic!("next_key must have returned None");
+ }
+
+ let e = unsafe { &*self.1 };
+ // increment the reference count because deserialize consumes `value`.
+ let value = unsafe { QObject::cloned_from_raw(e.value) };
+ let result = seed.deserialize(value);
+ self.1 = unsafe { bindings::qdict_next(self.0, self.1) };
+ result
+ }
+ }
+
+ let qdict = (qdict as *const bindings::QDict).cast_mut();
+ let e = unsafe { &*bindings::qdict_first(qdict) };
+ let mut deserializer = QDictDeserializer(qdict, e);
+ let map = visitor.visit_map(&mut deserializer)?;
+ if deserializer.1.is_null() {
+ Ok(map)
+ } else {
+ Err(serde::de::Error::invalid_length(
+ unsafe { bindings::qdict_size(qdict) },
+ &"fewer elements in map",
+ ))
+ }
+}
+
+fn visit_qnum_ref<'de, V>(qnum: QObject, visitor: V) -> Result<V::Value>
+where
+ V: Visitor<'de>,
+{
+ match_qobject! { (qnum) =>
+ i64(n) => visitor.visit_i64(n),
+ u64(n) => visitor.visit_u64(n),
+ f64(n) => visitor.visit_f64(n),
+ _ => Err(qnum.invalid_type(&"number")),
+ }
+}
+
+macro_rules! deserialize_number {
+ ($method:ident) => {
+ fn $method<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ visit_qnum_ref(self, visitor)
+ }
+ };
+}
+impl<'de> serde::Deserializer<'de> for QObject {
+ type Error = Error;
+
+ fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ () => visitor.visit_unit(),
+ bool(v) => visitor.visit_bool(v),
+ i64(n) => visitor.visit_i64(n),
+ u64(n) => visitor.visit_u64(n),
+ f64(n) => visitor.visit_f64(n),
+ CStr(cstr) => visitor.visit_borrowed_str(cstr.to_str()?),
+ QList(qlist) => visit_qlist_ref(qlist, visitor),
+ QDict(qdict) => visit_qdict_ref(qdict, visitor),
+ }
+ }
+
+ deserialize_number!(deserialize_i8);
+ deserialize_number!(deserialize_i16);
+ deserialize_number!(deserialize_i32);
+ deserialize_number!(deserialize_i64);
+ deserialize_number!(deserialize_i128);
+ deserialize_number!(deserialize_u8);
+ deserialize_number!(deserialize_u16);
+ deserialize_number!(deserialize_u32);
+ deserialize_number!(deserialize_u64);
+ deserialize_number!(deserialize_u128);
+ deserialize_number!(deserialize_f32);
+ deserialize_number!(deserialize_f64);
+
+ fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ () => visitor.visit_none(),
+ _ => visitor.visit_some(self),
+ }
+ }
+
+ fn deserialize_enum<V>(
+ self,
+ _name: &'static str,
+ _variants: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ CStr(cstr) => visitor.visit_borrowed_str(cstr.to_str()?),
+ QDict(qdict) => visit_qdict_ref(qdict, visitor),
+ _ => Err(self.invalid_type(&"string or map")),
+ }
+ }
+
+ #[inline]
+ fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let _ = name;
+ visitor.visit_newtype_struct(self)
+ }
+
+ fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ bool(v) => visitor.visit_bool(v),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ CStr(cstr) => visitor.visit_borrowed_str(cstr.to_str()?),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ CStr(cstr) => visitor.visit_borrowed_str(cstr.to_str()?),
+ QList(qlist) => visit_qlist_ref(qlist, visitor),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_bytes(visitor)
+ }
+
+ fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ () => visitor.visit_unit(),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_unit(visitor)
+ }
+
+ fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ QList(qlist) => visit_qlist_ref(qlist, visitor),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_seq(visitor)
+ }
+
+ fn deserialize_tuple_struct<V>(
+ self,
+ _name: &'static str,
+ _len: usize,
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_seq(visitor)
+ }
+
+ fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ QDict(qdict) => visit_qdict_ref(qdict, visitor),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_struct<V>(
+ self,
+ _name: &'static str,
+ _fields: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ match_qobject! { (self) =>
+ QList(qlist) => visit_qlist_ref(qlist, visitor),
+ QDict(qdict) => visit_qdict_ref(qdict, visitor),
+ _ => Err(self.invalid_type(&visitor)),
+ }
+ }
+
+ fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ visitor.visit_unit()
+ }
+}
+
+pub fn from_qobject<T>(value: QObject) -> Result<T>
+where
+ T: de::DeserializeOwned,
+{
+ T::deserialize(value)
+}
diff --git a/rust/util/src/qobject/error.rs b/rust/util/src/qobject/error.rs
index 5212e65c4f7..2d7c180187a 100644
--- a/rust/util/src/qobject/error.rs
+++ b/rust/util/src/qobject/error.rs
@@ -6,7 +6,7 @@
str::Utf8Error,
};
-use serde::ser;
+use serde::{de, ser};
#[derive(Debug)]
pub enum Error {
@@ -23,6 +23,12 @@ fn custom<T: Display>(msg: T) -> Self {
}
}
+impl de::Error for Error {
+ fn custom<T: Display>(msg: T) -> Self {
+ Error::Custom(msg.to_string())
+ }
+}
+
impl From<NulError> for Error {
fn from(_: NulError) -> Self {
Error::NulEncountered
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index aec635a5ccc..1c18a491720 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -7,6 +7,7 @@
#![deny(clippy::unwrap_used)]
mod deserialize;
+mod deserializer;
mod error;
mod serialize;
mod serializer;
@@ -20,6 +21,7 @@
};
use common::assert_field_type;
+pub use deserializer::from_qobject;
pub use error::{Error, Result};
pub use serializer::to_qobject;
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* Re: [PATCH 07/14] rust: add Deserializer (from_qobject) implementation for QObject
2025-10-01 8:00 ` [PATCH 07/14] rust: add Deserializer (from_qobject) " Paolo Bonzini
@ 2025-12-05 10:16 ` Zhao Liu
0 siblings, 0 replies; 55+ messages in thread
From: Zhao Liu @ 2025-12-05 10:16 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, qemu-rust, armbru, marcandre.lureau
On Wed, Oct 01, 2025 at 10:00:44AM +0200, Paolo Bonzini wrote:
> Date: Wed, 1 Oct 2025 10:00:44 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 07/14] rust: add Deserializer (from_qobject) implementation
> for QObject
> X-Mailer: git-send-email 2.51.0
>
> This allows creating any serializable data structure from QObject.
>
> Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> docs/devel/rust.rst | 1 +
> rust/util/meson.build | 1 +
> rust/util/src/qobject/deserializer.rs | 373 ++++++++++++++++++++++++++
> rust/util/src/qobject/error.rs | 8 +-
> rust/util/src/qobject/mod.rs | 2 +
> 5 files changed, 384 insertions(+), 1 deletion(-)
> create mode 100644 rust/util/src/qobject/deserializer.rs
...
> diff --git a/rust/util/src/qobject/deserializer.rs b/rust/util/src/qobject/deserializer.rs
> new file mode 100644
> index 00000000000..a2fe417e72a
> --- /dev/null
> +++ b/rust/util/src/qobject/deserializer.rs
> @@ -0,0 +1,373 @@
> +//! `QObject` deserializer
> +//!
> +//! This module implements a [`Deserializer`](serde::de::Deserializer) that
> +//! produces `QObject`s, allowing them to be turned into deserializable data
^^^^^^^^
Only a nit,
This "produces" word puzzled me for a while. I think it should be
"consumes".
Then the logic of 4 things did in this series should be the following?
serializer serialize
Rust struct ----------> QObject ---------> JSON
<---------- <---------
deserializer deserialize
Maybe we could have the similar documentation/decription in mod.rs or
somewhere to provide a high-level overview :).
> +//! structures (such as primitive data types, or structs that implement
> +//! `Deserialize`).
> +
The implementation itself looks good,
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
^ permalink raw reply [flat|nested] 55+ messages in thread
* [PATCH 08/14] rust/qobject: add Display/Debug
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (18 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 07/14] rust: add Deserializer (from_qobject) " Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 09/14] scripts/qapi: add QAPISchemaIfCond.rsgen() Paolo Bonzini
` (5 subsequent siblings)
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/util/src/qobject/mod.rs | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index 1c18a491720..b6e86f11a64 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -12,6 +12,7 @@
mod serialize;
mod serializer;
+use core::fmt::{self, Debug, Display};
use std::{
cell::UnsafeCell,
ffi::{c_char, CString},
@@ -231,6 +232,33 @@ fn drop(&mut self) {
}
}
+impl Display for QObject {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ // replace with a plain serializer?
+ match_qobject! { (self) =>
+ () => write!(f, "QNull"),
+ bool(b) => write!(f, "QBool({})", if b { "true" } else { "false" }),
+ i64(n) => write!(f, "QNumI64({})", n),
+ u64(n) => write!(f, "QNumU64({})", n),
+ f64(n) => write!(f, "QNumDouble({})", n),
+ CStr(s) => write!(f, "QString({})", s.to_str().unwrap_or("bad CStr")),
+ QList(_) => write!(f, "QList"),
+ QDict(_) => write!(f, "QDict"),
+ }
+ }
+}
+
+impl Debug for QObject {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let val = self.to_string();
+ f.debug_struct("QObject")
+ .field("ptr", &self.0.get())
+ .field("refcnt()", &self.refcnt())
+ .field("to_string()", &val)
+ .finish()
+ }
+}
+
macro_rules! match_qobject {
(@internal ($qobj:expr) =>
$(() => $unit:expr,)?
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 09/14] scripts/qapi: add QAPISchemaIfCond.rsgen()
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (19 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 08/14] rust/qobject: add Display/Debug Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 10/14] scripts/qapi: generate high-level Rust bindings Paolo Bonzini
` (4 subsequent siblings)
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Generate Rust #[cfg(...)] guards from QAPI 'if' conditions.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20210907121943.3498701-15-marcandre.lureau@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
scripts/qapi/common.py | 16 ++++++++++++++++
scripts/qapi/schema.py | 4 ++++
2 files changed, 20 insertions(+)
diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
index d7c8aa3365c..f16b9568bb9 100644
--- a/scripts/qapi/common.py
+++ b/scripts/qapi/common.py
@@ -199,6 +199,22 @@ def guardend(name: str) -> str:
name=c_fname(name).upper())
+def rsgen_ifcond(ifcond: Optional[Union[str, Dict[str, Any]]]) -> str:
+
+ def cfg(ifcond: Union[str, Dict[str, Any]]) -> str:
+ if isinstance(ifcond, str):
+ return ifcond
+ if isinstance(ifcond, list):
+ return ', '.join([cfg(c) for c in ifcond])
+ oper, operands = next(iter(ifcond.items()))
+ operands = cfg(operands)
+ return f'{oper}({operands})'
+
+ if not ifcond:
+ return ''
+ return '#[cfg(%s)]' % cfg(ifcond)
+
+
def gen_ifcond(ifcond: Optional[Union[str, Dict[str, Any]]],
cond_fmt: str, not_fmt: str,
all_operator: str, any_operator: str) -> str:
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 8d88b40de2e..848a7401251 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -37,6 +37,7 @@
docgen_ifcond,
gen_endif,
gen_if,
+ rsgen_ifcond,
)
from .error import QAPIError, QAPISemError, QAPISourceError
from .expr import check_exprs
@@ -63,6 +64,9 @@ def gen_endif(self) -> str:
def docgen(self) -> str:
return docgen_ifcond(self.ifcond)
+ def rsgen(self) -> str:
+ return rsgen_ifcond(self.ifcond)
+
def is_present(self) -> bool:
return bool(self.ifcond)
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 10/14] scripts/qapi: generate high-level Rust bindings
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (20 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 09/14] scripts/qapi: add QAPISchemaIfCond.rsgen() Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 11/14] scripts/qapi: strip trailing whitespaces Paolo Bonzini
` (3 subsequent siblings)
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Generate high-level native Rust declarations for the QAPI types.
- char* is mapped to String, scalars to there corresponding Rust types
- enums are simply aliased from FFI
- has_foo/foo members are mapped to Option<T>
- lists are represented as Vec<T>
- structures have Rust versions, with To/From FFI conversions
- alternate are represented as Rust enum
- unions are represented in a similar way as in C: a struct S with a "u"
member (since S may have extra 'base' fields). However, the discriminant
isn't a member of S, since Rust enum already include it.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20210907121943.3498701-21-marcandre.lureau@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
meson.build | 4 +-
scripts/qapi/backend.py | 28 +++-
scripts/qapi/main.py | 4 +-
scripts/qapi/rs.py | 176 +++++++++++++++++++
scripts/qapi/rs_types.py | 354 +++++++++++++++++++++++++++++++++++++++
5 files changed, 562 insertions(+), 4 deletions(-)
create mode 100644 scripts/qapi/rs.py
create mode 100644 scripts/qapi/rs_types.py
diff --git a/meson.build b/meson.build
index 0eb4f850582..8236205d4c5 100644
--- a/meson.build
+++ b/meson.build
@@ -3559,12 +3559,14 @@ qapi_gen_depends = [ meson.current_source_dir() / 'scripts/qapi/__init__.py',
meson.current_source_dir() / 'scripts/qapi/introspect.py',
meson.current_source_dir() / 'scripts/qapi/main.py',
meson.current_source_dir() / 'scripts/qapi/parser.py',
+ meson.current_source_dir() / 'scripts/qapi/rs_types.py',
meson.current_source_dir() / 'scripts/qapi/schema.py',
meson.current_source_dir() / 'scripts/qapi/source.py',
meson.current_source_dir() / 'scripts/qapi/types.py',
meson.current_source_dir() / 'scripts/qapi/features.py',
meson.current_source_dir() / 'scripts/qapi/visit.py',
- meson.current_source_dir() / 'scripts/qapi-gen.py'
+ meson.current_source_dir() / 'scripts/qapi-gen.py',
+ meson.current_source_dir() / 'scripts/qapi/rs.py',
]
tracetool = [
diff --git a/scripts/qapi/backend.py b/scripts/qapi/backend.py
index 49ae6ecdd33..9b9c9708f46 100644
--- a/scripts/qapi/backend.py
+++ b/scripts/qapi/backend.py
@@ -7,6 +7,7 @@
from .events import gen_events
from .features import gen_features
from .introspect import gen_introspect
+from .rs_types import gen_rs_types
from .schema import QAPISchema
from .types import gen_types
from .visit import gen_visit
@@ -36,7 +37,7 @@ def generate(self,
"""
-class QAPICBackend(QAPIBackend):
+class QAPICodeBackend(QAPIBackend):
# pylint: disable=too-few-public-methods
def generate(self,
@@ -63,3 +64,28 @@ def generate(self,
gen_commands(schema, output_dir, prefix, gen_tracing)
gen_events(schema, output_dir, prefix)
gen_introspect(schema, output_dir, prefix, unmask)
+
+
+
+class QAPIRsBackend(QAPIBackend):
+ # pylint: disable=too-few-public-methods
+
+ def generate(self,
+ schema: QAPISchema,
+ output_dir: str,
+ prefix: str,
+ unmask: bool,
+ builtins: bool,
+ gen_tracing: bool) -> None:
+ """
+ Generate Rust code for the given schema into the target directory.
+
+ :param schema_file: The primary QAPI schema file.
+ :param output_dir: The output directory to store generated code.
+ :param prefix: Optional C-code prefix for symbol names.
+ :param unmask: Expose non-ABI names through introspection?
+ :param builtins: Generate code for built-in types?
+
+ :raise QAPIError: On failures.
+ """
+ gen_rs_types(schema, output_dir, prefix, builtins)
diff --git a/scripts/qapi/main.py b/scripts/qapi/main.py
index 0e2a6ae3f07..4ad75e213f5 100644
--- a/scripts/qapi/main.py
+++ b/scripts/qapi/main.py
@@ -12,7 +12,7 @@
import sys
from typing import Optional
-from .backend import QAPIBackend, QAPICBackend
+from .backend import QAPIBackend, QAPICodeBackend
from .common import must_match
from .error import QAPIError
from .schema import QAPISchema
@@ -27,7 +27,7 @@ def invalid_prefix_char(prefix: str) -> Optional[str]:
def create_backend(path: str) -> QAPIBackend:
if path is None:
- return QAPICBackend()
+ return QAPICodeBackend()
module_path, dot, class_name = path.rpartition('.')
if not dot:
diff --git a/scripts/qapi/rs.py b/scripts/qapi/rs.py
new file mode 100644
index 00000000000..37b9d4ad569
--- /dev/null
+++ b/scripts/qapi/rs.py
@@ -0,0 +1,176 @@
+# This work is licensed under the terms of the GNU GPL, version 2.
+# See the COPYING file in the top-level directory.
+"""
+QAPI Rust generator
+"""
+
+import os
+import re
+import subprocess
+from typing import NamedTuple, Optional
+
+from .common import POINTER_SUFFIX
+from .gen import QAPIGen
+from .schema import QAPISchemaModule, QAPISchemaVisitor
+
+
+# see to_snake_case() below
+snake_case = re.compile(r'((?<=[a-z0-9])[A-Z]|(?!^)[A-Z](?=[a-z]))')
+
+
+rs_name_trans = str.maketrans('.-', '__')
+
+
+# Map @name to a valid Rust identifier.
+# If @protect, avoid returning certain ticklish identifiers (like
+# keywords) by prepending raw identifier prefix 'r#'.
+def rs_name(name: str, protect: bool = True) -> str:
+ name = name.translate(rs_name_trans)
+ if name[0].isnumeric():
+ name = '_' + name
+ if not protect:
+ return name
+ # based from the list:
+ # https://doc.rust-lang.org/reference/keywords.html
+ if name in ('Self', 'abstract', 'as', 'async',
+ 'await', 'become', 'box', 'break',
+ 'const', 'continue', 'crate', 'do',
+ 'dyn', 'else', 'enum', 'extern',
+ 'false', 'final', 'fn', 'for',
+ 'if', 'impl', 'in', 'let',
+ 'loop', 'macro', 'match', 'mod',
+ 'move', 'mut', 'override', 'priv',
+ 'pub', 'ref', 'return', 'self',
+ 'static', 'struct', 'super', 'trait',
+ 'true', 'try', 'type', 'typeof',
+ 'union', 'unsafe', 'unsized', 'use',
+ 'virtual', 'where', 'while', 'yield'):
+ name = 'r#' + name
+ # avoid some clashes with the standard library
+ if name in ('String',):
+ name = 'Qapi' + name
+
+ return name
+
+
+def rs_type(c_type: str,
+ qapi_ns: str = 'qapi::',
+ optional: bool = False,
+ box: bool = False) -> str:
+ (is_pointer, _, is_list, c_type) = rs_ctype_parse(c_type)
+ to_rs = {
+ 'QNull': '()',
+ 'QObject': 'QObject',
+ 'bool': 'bool',
+ 'char': 'i8',
+ 'double': 'f64',
+ 'int': 'i64',
+ 'int16': 'i16',
+ 'int16_t': 'i16',
+ 'int32': 'i32',
+ 'int32_t': 'i32',
+ 'int64': 'i64',
+ 'int64_t': 'i64',
+ 'int8': 'i8',
+ 'int8_t': 'i8',
+ 'number': 'f64',
+ 'size': 'u64',
+ 'str': 'String',
+ 'uint16': 'u16',
+ 'uint16_t': 'u16',
+ 'uint32': 'u32',
+ 'uint32_t': 'u32',
+ 'uint64': 'u64',
+ 'uint64_t': 'u64',
+ 'uint8': 'u8',
+ 'uint8_t': 'u8',
+ 'String': 'QapiString',
+ }
+ if is_pointer:
+ to_rs.update({
+ 'char': 'String',
+ })
+
+ if is_list:
+ c_type = c_type[:-4]
+
+ ret = to_rs.get(c_type, qapi_ns + c_type)
+ if is_list:
+ ret = 'Vec<%s>' % ret
+ elif is_pointer and c_type not in to_rs and box:
+ ret = 'Box<%s>' % ret
+ if optional:
+ ret = 'Option<%s>' % ret
+ return ret
+
+
+class CType(NamedTuple):
+ is_pointer: bool
+ is_const: bool
+ is_list: bool
+ c_type: str
+
+
+def rs_ctype_parse(c_type: str) -> CType:
+ is_pointer = False
+ if c_type.endswith(POINTER_SUFFIX):
+ is_pointer = True
+ c_type = c_type[:-len(POINTER_SUFFIX)]
+ is_list = c_type.endswith('List')
+ is_const = False
+ if c_type.startswith('const '):
+ is_const = True
+ c_type = c_type[6:]
+
+ c_type = rs_name(c_type)
+ return CType(is_pointer, is_const, is_list, c_type)
+
+
+def to_camel_case(value: str) -> str:
+ # special case for last enum value
+ if value == '_MAX':
+ return value
+ raw_id = False
+ if value.startswith('r#'):
+ raw_id = True
+ value = value[2:]
+ value = ''.join('_' + word if word[0].isdigit()
+ else word[:1].upper() + word[1:]
+ for word in filter(None, re.split("[-_]+", value)))
+ if raw_id:
+ return 'r#' + value
+ return value
+
+
+def to_snake_case(value: str) -> str:
+ return snake_case.sub(r'_\1', value).lower()
+
+
+class QAPIGenRs(QAPIGen):
+ pass
+
+
+class QAPISchemaRsVisitor(QAPISchemaVisitor):
+
+ def __init__(self, prefix: str, what: str):
+ super().__init__()
+ self._prefix = prefix
+ self._what = what
+ self._gen = QAPIGenRs(self._prefix + self._what + '.rs')
+ self._main_module: Optional[str] = None
+
+ def visit_module(self, name: Optional[str]) -> None:
+ if name is None:
+ return
+ if QAPISchemaModule.is_user_module(name):
+ if self._main_module is None:
+ self._main_module = name
+
+ def write(self, output_dir: str) -> None:
+ self._gen.write(output_dir)
+
+ pathname = os.path.join(output_dir, self._gen.fname)
+ try:
+ subprocess.check_call(['rustfmt', pathname])
+ except FileNotFoundError:
+ pass
diff --git a/scripts/qapi/rs_types.py b/scripts/qapi/rs_types.py
new file mode 100644
index 00000000000..f124106d7f0
--- /dev/null
+++ b/scripts/qapi/rs_types.py
@@ -0,0 +1,354 @@
+# This work is licensed under the terms of the GNU GPL, version 2.
+# See the COPYING file in the top-level directory.
+"""
+QAPI Rust types generator
+"""
+
+from typing import List, Optional, Set
+
+from .common import camel_to_upper, mcgen
+from .rs import (
+ QAPISchemaRsVisitor,
+ rs_name,
+ rs_type,
+ to_camel_case,
+ to_snake_case,
+)
+from .schema import (
+ QAPISchema,
+ QAPISchemaEnumMember,
+ QAPISchemaFeature,
+ QAPISchemaIfCond,
+ QAPISchemaBuiltinType,
+ QAPISchemaAlternateType,
+ QAPISchemaArrayType,
+ QAPISchemaObjectType,
+ QAPISchemaObjectTypeMember,
+ QAPISchemaType,
+ QAPISchemaVariants,
+)
+from .source import QAPISourceInfo
+
+
+objects_seen = set()
+
+
+def gen_rs_variants_to_tag(name: str,
+ ifcond: QAPISchemaIfCond,
+ variants: QAPISchemaVariants) -> str:
+ ret = mcgen('''
+
+%(cfg)s
+impl From<&%(rs_name)sVariant> for %(tag)s {
+ fn from(e: &%(rs_name)sVariant) -> Self {
+ match e {
+ ''',
+ cfg=ifcond.rsgen(),
+ rs_name=rs_name(name),
+ tag=rs_type(variants.tag_member.type.c_type(), ''))
+
+ for var in variants.variants:
+ type_name = var.type.name
+ var_name = to_camel_case(rs_name(var.name))
+ patt = '(_)'
+ if type_name == 'q_empty':
+ patt = ''
+ ret += mcgen('''
+ %(cfg)s
+ %(rs_name)sVariant::%(var_name)s%(patt)s => Self::%(var_name)s,
+''',
+ cfg=var.ifcond.rsgen(),
+ rs_name=rs_name(name),
+ var_name=var_name,
+ patt=patt)
+
+ ret += mcgen('''
+ }
+ }
+}
+''')
+ return ret
+
+
+def gen_rs_variants(name: str,
+ ifcond: QAPISchemaIfCond,
+ variants: QAPISchemaVariants) -> str:
+ ret = mcgen('''
+
+%(cfg)s
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum %(rs_name)sVariant {
+''',
+ cfg=ifcond.rsgen(),
+ rs_name=rs_name(name))
+
+ for var in variants.variants:
+ type_name = var.type.name
+ var_name = to_camel_case(rs_name(var.name, False))
+ if type_name == 'q_empty':
+ ret += mcgen('''
+ %(cfg)s
+ %(var_name)s,
+''',
+ cfg=var.ifcond.rsgen(),
+ var_name=var_name)
+ else:
+ c_type = var.type.c_unboxed_type()
+ if c_type.endswith('_wrapper'):
+ c_type = c_type[6:-8] # remove q_obj*-wrapper
+ ret += mcgen('''
+ %(cfg)s
+ %(var_name)s(%(rs_type)s),
+''',
+ cfg=var.ifcond.rsgen(),
+ var_name=var_name,
+ rs_type=rs_type(c_type, ''))
+
+ ret += mcgen('''
+}
+''')
+
+ ret += gen_rs_variants_to_tag(name, ifcond, variants)
+
+ return ret
+
+
+def gen_rs_members(members: List[QAPISchemaObjectTypeMember],
+ exclude: Optional[List[str]] = None) -> List[str]:
+ exclude = exclude or []
+ return [f"{m.ifcond.rsgen()} {to_snake_case(rs_name(m.name))}"
+ for m in members if m.name not in exclude]
+
+
+def has_recursive_type(memb: QAPISchemaType,
+ name: str,
+ visited: Set[str]) -> bool:
+ if name == memb.name:
+ return True
+ if memb.name in visited:
+ return False
+ visited.add(memb.name)
+ if isinstance(memb, QAPISchemaObjectType):
+ if memb.base and has_recursive_type(memb.base, name, visited):
+ return True
+ if memb.branches and any(has_recursive_type(m.type, name, visited) for m in memb.branches.variants):
+ return True
+ if any(has_recursive_type(m.type, name, visited) for m in memb.members):
+ return True
+ return any(has_recursive_type(m.type, name, visited) for m in memb.local_members)
+ elif isinstance(memb, QAPISchemaAlternateType):
+ return any(has_recursive_type(m.type, name, visited) for m in memb.alternatives.variants)
+ elif isinstance(memb, QAPISchemaArrayType):
+ return has_recursive_type(memb.element_type, name, visited)
+ else:
+ pass
+ return False
+
+
+def gen_struct_members(members: List[QAPISchemaObjectTypeMember],
+ name: str) -> str:
+ ret = ''
+ for memb in members:
+ is_recursive = has_recursive_type(memb.type, name, set())
+ typ = rs_type(memb.type.c_type(), '', optional=memb.optional, box=is_recursive)
+ ret += mcgen('''
+ %(cfg)s
+ pub %(rs_name)s: %(rs_type)s,
+''',
+ cfg=memb.ifcond.rsgen(),
+ rs_type=typ,
+ rs_name=to_snake_case(rs_name(memb.name)))
+ return ret
+
+
+def gen_rs_object(name: str,
+ ifcond: QAPISchemaIfCond,
+ base: Optional[QAPISchemaObjectType],
+ members: List[QAPISchemaObjectTypeMember],
+ variants: Optional[QAPISchemaVariants]) -> str:
+ if name in objects_seen:
+ return ''
+
+ if variants:
+ members = [m for m in members
+ if m.name != variants.tag_member.name]
+
+ ret = ''
+ objects_seen.add(name)
+
+ if variants:
+ ret += gen_rs_variants(name, ifcond, variants)
+
+ ret += mcgen('''
+
+%(cfg)s
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct %(rs_name)s {
+''',
+ cfg=ifcond.rsgen(),
+ rs_name=rs_name(name))
+
+ if base:
+ if not base.is_implicit():
+ ret += mcgen('''
+ // Members inherited:
+''',
+ c_name=base.c_name())
+ base_members = base.members
+ if variants:
+ base_members = [m for m in base.members
+ if m.name != variants.tag_member.name]
+ ret += gen_struct_members(base_members, name)
+ if not base.is_implicit():
+ ret += mcgen('''
+ // Own members:
+''')
+
+ ret += gen_struct_members(members, name)
+
+ if variants:
+ ret += mcgen('''
+ pub u: %(rs_type)sVariant,
+''', rs_type=rs_name(name))
+ ret += mcgen('''
+}
+''')
+ return ret
+
+
+def gen_rs_enum(name: str,
+ ifcond: QAPISchemaIfCond,
+ members: List[QAPISchemaEnumMember]) -> str:
+ # append automatically generated _max value
+ enum_members = members + [QAPISchemaEnumMember('_MAX', None)]
+
+ ret = mcgen('''
+
+%(cfg)s
+#[repr(u32)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, common::TryInto)]
+pub enum %(rs_name)s {
+''',
+ cfg=ifcond.rsgen(),
+ rs_name=rs_name(name))
+
+ for member in enum_members:
+ ret += mcgen('''
+ %(cfg)s
+ %(c_enum)s,
+''',
+ cfg=member.ifcond.rsgen(),
+ c_enum=to_camel_case(rs_name(member.name)))
+ # picked the first, since that's what malloc0 does
+ # but arguably could use _MAX instead, or a qapi annotation
+ default = to_camel_case(rs_name(enum_members[0].name))
+ ret += mcgen('''
+}
+
+%(cfg)s
+impl Default for %(rs_name)s {
+ #[inline]
+ fn default() -> %(rs_name)s {
+ Self::%(default)s
+ }
+}
+''',
+ cfg=ifcond.rsgen(),
+ rs_name=rs_name(name),
+ default=default)
+ return ret
+
+
+def gen_rs_alternate(name: str,
+ ifcond: QAPISchemaIfCond,
+ variants: QAPISchemaVariants) -> str:
+ if name in objects_seen:
+ return ''
+
+ ret = ''
+ objects_seen.add(name)
+
+ ret += mcgen('''
+%(cfg)s
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum %(rs_name)s {
+''',
+ cfg=ifcond.rsgen(),
+ rs_name=rs_name(name))
+
+ for var in variants.variants:
+ if var.type.name == 'q_empty':
+ continue
+ is_recursive = has_recursive_type(var.type, name, set())
+ ret += mcgen('''
+ %(cfg)s
+ %(mem_name)s(%(rs_type)s),
+''',
+ cfg=var.ifcond.rsgen(),
+ rs_type=rs_type(var.type.c_unboxed_type(), '', box=is_recursive),
+ mem_name=to_camel_case(rs_name(var.name)))
+
+ ret += mcgen('''
+}
+''')
+ return ret
+
+
+class QAPISchemaGenRsTypeVisitor(QAPISchemaRsVisitor):
+
+ def __init__(self, prefix: str) -> None:
+ super().__init__(prefix, 'qapi-types')
+
+ def visit_begin(self, schema: QAPISchema) -> None:
+ # don't visit the empty type
+ objects_seen.add(schema.the_empty_object_type.name)
+ self._gen.preamble_add(
+ mcgen('''
+// generated by qapi-gen, DO NOT EDIT
+
+#![allow(unexpected_cfgs)]
+#![allow(non_camel_case_types)]
+#![allow(non_upper_case_globals)]
+
+use serde_derive::{Serialize, Deserialize};
+
+use util::qobject::QObject;
+'''))
+
+ def visit_object_type(self,
+ name: str,
+ info: Optional[QAPISourceInfo],
+ ifcond: QAPISchemaIfCond,
+ features: List[QAPISchemaFeature],
+ base: Optional[QAPISchemaObjectType],
+ members: List[QAPISchemaObjectTypeMember],
+ branches: Optional[QAPISchemaVariants]) -> None:
+ if name.startswith('q_'):
+ return
+ self._gen.add(gen_rs_object(name, ifcond, base, members, branches))
+
+ def visit_enum_type(self,
+ name: str,
+ info: Optional[QAPISourceInfo],
+ ifcond: QAPISchemaIfCond,
+ features: List[QAPISchemaFeature],
+ members: List[QAPISchemaEnumMember],
+ prefix: Optional[str]) -> None:
+ self._gen.add(gen_rs_enum(name, ifcond, members))
+
+ def visit_alternate_type(self,
+ name: str,
+ info: Optional[QAPISourceInfo],
+ ifcond: QAPISchemaIfCond,
+ features: List[QAPISchemaFeature],
+ alternatives: QAPISchemaVariants) -> None:
+ self._gen.add(gen_rs_alternate(name, ifcond, alternatives))
+
+
+def gen_rs_types(schema: QAPISchema, output_dir: str, prefix: str,
+ builtins: bool) -> None:
+ # pylint: disable=unused-argument
+ # TODO: builtins?
+ vis = QAPISchemaGenRsTypeVisitor(prefix)
+ schema.visit(vis)
+ vis.write(output_dir)
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 11/14] scripts/qapi: strip trailing whitespaces
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (21 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 10/14] scripts/qapi: generate high-level Rust bindings Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 12/14] scripts/rustc_args: add --no-strict-cfg Paolo Bonzini
` (2 subsequent siblings)
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
This help workaround a rustfmt issue.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20210907121943.3498701-16-marcandre.lureau@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
scripts/qapi/gen.py | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
index 0c9b8db3b02..c9721545ea7 100644
--- a/scripts/qapi/gen.py
+++ b/scripts/qapi/gen.py
@@ -58,7 +58,11 @@ def add(self, text: str) -> None:
self._body += text
def get_content(self) -> str:
- return self._top() + self._preamble + self._body + self._bottom()
+ content = self._top() + self._preamble + self._body + self._bottom()
+ # delete trailing white-spaces (working around
+ # https://github.com/rust-lang/rustfmt/issues/4248)
+ content = re.sub(r'\s+$', '\n', content, 0, re.M)
+ return content
def _top(self) -> str:
# pylint: disable=no-self-use
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 12/14] scripts/rustc_args: add --no-strict-cfg
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (22 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 11/14] scripts/qapi: strip trailing whitespaces Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 13/14] rust/util: build QAPI types Paolo Bonzini
2025-10-01 8:00 ` [PATCH 14/14] rust: start qapi tests Paolo Bonzini
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Allow to generate all --cfg flags, regardless of Cargo.toml content.
We can't easily list and include all the features used by QAPI types.
Access via #[cfg()] then requires #![allow(unexpected_cfgs)].
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
scripts/rust/rustc_args.py | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/scripts/rust/rustc_args.py b/scripts/rust/rustc_args.py
index 63b0748e0d3..c70b95b8bed 100644
--- a/scripts/rust/rustc_args.py
+++ b/scripts/rust/rustc_args.py
@@ -116,7 +116,7 @@ def generate_lint_flags(cargo_toml: CargoTOML, strict_lints: bool) -> Iterable[s
yield from lint.flags
-def generate_cfg_flags(header: str, cargo_toml: CargoTOML) -> Iterable[str]:
+def generate_cfg_flags(header: str, cargo_toml: Optional[CargoTOML]) -> Iterable[str]:
"""Converts defines from config[..].h headers to rustc --cfg flags."""
with open(header, encoding="utf-8") as cfg:
@@ -125,8 +125,9 @@ def generate_cfg_flags(header: str, cargo_toml: CargoTOML) -> Iterable[str]:
cfg_list = []
for cfg in config:
name = cfg[0]
- if f'cfg({name})' not in cargo_toml.check_cfg:
- continue
+ if cargo_toml:
+ if f'cfg({name})' not in cargo_toml.check_cfg:
+ continue
if len(cfg) >= 2 and cfg[1] != "1":
continue
cfg_list.append("--cfg")
@@ -194,6 +195,13 @@ def main() -> None:
help="apply stricter checks (for nightly Rust)",
default=False,
)
+ parser.add_argument(
+ "--no-strict-cfg",
+ help="only generate expected cfg",
+ action="store_false",
+ dest="strict_cfg",
+ default=True,
+ )
args = parser.parse_args()
if args.verbose:
logging.basicConfig(level=logging.DEBUG)
@@ -224,7 +232,7 @@ def main() -> None:
print(f'cfg(feature,values("{feature}"))')
for header in args.config_headers:
- for tok in generate_cfg_flags(header, cargo_toml):
+ for tok in generate_cfg_flags(header, cargo_toml if args.strict_cfg else None):
print(tok)
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 13/14] rust/util: build QAPI types
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (23 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 12/14] scripts/rustc_args: add --no-strict-cfg Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
2025-10-01 8:00 ` [PATCH 14/14] rust: start qapi tests Paolo Bonzini
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/util/wrapper.h | 1 +
qapi/meson.build | 6 ++++++
rust/Cargo.lock | 1 +
rust/util/Cargo.toml | 1 +
rust/util/meson.build | 18 +++++++++++++++++-
rust/util/src/qobject/mod.rs | 9 +++++++++
6 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/rust/util/wrapper.h b/rust/util/wrapper.h
index 0907dd59142..c88820a5e5b 100644
--- a/rust/util/wrapper.h
+++ b/rust/util/wrapper.h
@@ -37,3 +37,4 @@ typedef enum memory_order {
#include "qobject/qobject.h"
#include "qobject/qlist.h"
#include "qobject/qdict.h"
+#include "qobject/qjson.h"
diff --git a/qapi/meson.build b/qapi/meson.build
index ca6b61a608d..5d4b55b47f8 100644
--- a/qapi/meson.build
+++ b/qapi/meson.build
@@ -129,3 +129,9 @@ foreach output : qapi_outputs
util_ss.add(qapi_files[i])
i = i + 1
endforeach
+
+qapi_rs_files = custom_target('QAPI Rust',
+ output: 'qapi-types.rs',
+ input: [ files('qapi-schema.json') ],
+ command: [ qapi_gen, '-o', 'qapi', '-b', '@INPUT0@', '-B', 'qapi.backend.QAPIRsBackend' ],
+ depend_files: [ qapi_inputs, qapi_gen_depends ])
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index c1075e11d6c..991533d92c1 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -447,6 +447,7 @@ dependencies = [
"glib-sys",
"libc",
"serde",
+ "serde_derive",
]
[[package]]
diff --git a/rust/util/Cargo.toml b/rust/util/Cargo.toml
index 554004816eb..9f6c52c5acd 100644
--- a/rust/util/Cargo.toml
+++ b/rust/util/Cargo.toml
@@ -18,6 +18,7 @@ foreign = { workspace = true }
glib-sys = { workspace = true }
libc = { workspace = true }
serde = { workspace = true }
+serde_derive = { workspace = true }
common = { path = "../common" }
[lints]
diff --git a/rust/util/meson.build b/rust/util/meson.build
index 45366d03786..a2d0e6ded0d 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -50,7 +50,7 @@ _util_rs = static_library(
dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs, serde_rs, qom, qemuutil],
)
-util_rs = declare_dependency(link_with: [_util_rs], dependencies: [qemuutil, qom])
+util_rs = declare_dependency(link_with: [_util_rs], dependencies: [])
rust.test('rust-util-tests', _util_rs,
dependencies: [qemuutil, qom],
@@ -64,3 +64,19 @@ rust.doctest('rust-util-rs-doctests',
dependencies: util_rs,
suite: ['doc', 'rust']
)
+
+_qapi_cfg = run_command(rustc_args,
+ '--no-strict-cfg',
+ '--config-headers', config_host_h,
+ capture: true, check: true).stdout().strip().splitlines()
+
+_qapi_rs = static_library(
+ 'qapi',
+ qapi_rs_files,
+ rust_args: _qapi_cfg,
+ override_options: ['rust_std=2021', 'build.rust_std=2021'],
+ rust_abi: 'rust',
+ dependencies: [common_rs, util_rs, serde_rs],
+)
+
+qapi_rs = declare_dependency(link_with: [_qapi_rs])
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index b6e86f11a64..f2618c86473 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -13,6 +13,7 @@
mod serializer;
use core::fmt::{self, Debug, Display};
+use foreign::prelude::*;
use std::{
cell::UnsafeCell,
ffi::{c_char, CString},
@@ -104,6 +105,14 @@ fn refcnt(&self) -> &AtomicUsize {
let qobj = self.0.get();
unsafe { AtomicUsize::from_ptr(addr_of_mut!((*qobj).base.refcnt)) }
}
+
+ pub fn to_json(&self) -> String {
+ let qobj = self.0.get();
+ unsafe {
+ let json = bindings::qobject_to_json(qobj);
+ glib_sys::g_string_free(json, glib_sys::GFALSE).into_native()
+ }
+ }
}
impl From<()> for QObject {
--
2.51.0
^ permalink raw reply related [flat|nested] 55+ messages in thread* [PATCH 14/14] rust: start qapi tests
2025-10-01 7:49 [PATCH 00/11] rust: migration: add high-level migration wrappers Paolo Bonzini
` (24 preceding siblings ...)
2025-10-01 8:00 ` [PATCH 13/14] rust/util: build QAPI types Paolo Bonzini
@ 2025-10-01 8:00 ` Paolo Bonzini
25 siblings, 0 replies; 55+ messages in thread
From: Paolo Bonzini @ 2025-10-01 8:00 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-rust, armbru, marcandre.lureau
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/tests/meson.build | 10 +++++++---
rust/tests/tests/integration.rs | 2 ++
rust/tests/tests/qapi.rs | 35 +++++++++++++++++++++++++++++++++
3 files changed, 44 insertions(+), 3 deletions(-)
create mode 100644 rust/tests/tests/integration.rs
create mode 100644 rust/tests/tests/qapi.rs
diff --git a/rust/tests/meson.build b/rust/tests/meson.build
index 00688c66fb1..c36cab1886e 100644
--- a/rust/tests/meson.build
+++ b/rust/tests/meson.build
@@ -1,11 +1,15 @@
test('rust-integration',
executable(
'rust-integration',
- files('tests/vmstate_tests.rs'),
+ files(
+ 'tests/integration.rs',
+ 'tests/vmstate_tests.rs',
+ 'tests/qapi.rs',
+ ),
override_options: ['rust_std=2021', 'build.rust_std=2021'],
- rust_args: ['--test'],
+ rust_args: ['--test'] + _qapi_cfg,
install: false,
- dependencies: [bql_rs, common_rs, util_rs, migration_rs, qom_rs]),
+ dependencies: [bql_rs, common_rs, util_rs, migration_rs, qom_rs, qapi_rs]),
args: [
'--test', '--test-threads', '1',
'--format', 'pretty',
diff --git a/rust/tests/tests/integration.rs b/rust/tests/tests/integration.rs
new file mode 100644
index 00000000000..ebc17cb5550
--- /dev/null
+++ b/rust/tests/tests/integration.rs
@@ -0,0 +1,2 @@
+mod qapi;
+mod vmstate_tests;
diff --git a/rust/tests/tests/qapi.rs b/rust/tests/tests/qapi.rs
new file mode 100644
index 00000000000..3a54d37edaa
--- /dev/null
+++ b/rust/tests/tests/qapi.rs
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#![allow(unexpected_cfgs)]
+
+use qapi;
+use util::qobject::{from_qobject, to_qobject};
+
+#[test]
+fn test_qapi() {
+ let sa = qapi::InetSocketAddress {
+ host: "host-val".to_string(),
+ port: "port-val".to_string(),
+ numeric: None,
+ to: None,
+ ipv4: None,
+ ipv6: None,
+ keep_alive: None,
+ #[cfg(HAVE_TCP_KEEPCNT)]
+ keep_alive_count: None,
+ #[cfg(HAVE_TCP_KEEPIDLE)]
+ keep_alive_idle: Some(42),
+ #[cfg(HAVE_TCP_KEEPINTVL)]
+ keep_alive_interval: None,
+ #[cfg(HAVE_IPPROTO_MPTCP)]
+ mptcp: None,
+ };
+
+ // let qi: QObject = 32.into();
+ // dbg!(&qi);
+
+ let qsa = to_qobject(&sa).unwrap();
+ let _json = qsa.to_json();
+ let sa: qapi::InetSocketAddress = from_qobject(qsa).unwrap();
+ dbg!(sa);
+}
--
2.51.0
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