Arrays, pointers and cells use a VMStateField that is based on that for the inner type. The implementation therefore delegates to the VMState implementation of the inner type.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- rust/qemu-api/src/vmstate.rs | 66 +++++++++++++++++++++++++++++++++++- 1 file changed, 65 insertions(+), 1 deletion(-) diff --git a/rust/qemu-api/src/vmstate.rs b/rust/qemu-api/src/vmstate.rs index bfcf06e8f1d..e20f27b172b 100644 --- a/rust/qemu-api/src/vmstate.rs +++ b/rust/qemu-api/src/vmstate.rs @@ -19,8 +19,9 @@ //! `include/migration/vmstate.h`. These are not type-safe and should not be //! used if the equivalent functionality is available with `vmstate_of!`. -use core::marker::PhantomData; +use core::{marker::PhantomData, mem, ptr::NonNull}; +use crate::bindings::VMStateFlags; pub use crate::bindings::{VMStateDescription, VMStateField}; /// This macro is used to call a function with a generic argument bound @@ -108,6 +109,69 @@ pub const fn with_version_id(mut self, version_id: i32) -> Self { self.version_id = version_id; self } + + #[must_use] + pub const fn with_array_flag(mut self, num: usize) -> Self { + assert!(num <= 0x7FFF_FFFFusize); + assert!((self.flags.0 & VMStateFlags::VMS_ARRAY.0) == 0); + if (self.flags.0 & VMStateFlags::VMS_POINTER.0) != 0 { + self.flags = VMStateFlags(self.flags.0 & !VMStateFlags::VMS_POINTER.0); + self.flags = VMStateFlags(self.flags.0 | VMStateFlags::VMS_ARRAY_OF_POINTER.0); + } + self.flags = VMStateFlags(self.flags.0 & !VMStateFlags::VMS_SINGLE.0); + self.flags = VMStateFlags(self.flags.0 | VMStateFlags::VMS_ARRAY.0); + self.num = num as i32; + self + } + + #[must_use] + pub const fn with_pointer_flag(mut self) -> Self { + assert!((self.flags.0 & VMStateFlags::VMS_POINTER.0) == 0); + self.flags = VMStateFlags(self.flags.0 | VMStateFlags::VMS_POINTER.0); + self + } +} + +// Transparent wrappers: just use the internal type + +macro_rules! impl_vmstate_transparent { + ($type:ty where $base:tt: VMState $($where:tt)*) => { + unsafe impl<$base> VMState for $type where $base: VMState $($where)* { + const BASE: VMStateField = VMStateField { + size: mem::size_of::<$type>(), + ..<$base as VMState>::BASE + }; + } + }; +} + +impl_vmstate_transparent!(std::cell::Cell<T> where T: VMState); +impl_vmstate_transparent!(std::cell::UnsafeCell<T> where T: VMState); +impl_vmstate_transparent!(crate::cell::BqlCell<T> where T: VMState); +impl_vmstate_transparent!(crate::cell::BqlRefCell<T> where T: VMState); + +// Pointer types using the underlying type's VMState plus VMS_POINTER + +macro_rules! impl_vmstate_pointer { + ($type:ty where $base:tt: VMState $($where:tt)*) => { + unsafe impl<$base> VMState for $type where $base: VMState $($where)* { + const SCALAR_TYPE: VMStateFieldType = <T as VMState>::SCALAR_TYPE; + const BASE: VMStateField = <$base as VMState>::BASE.with_pointer_flag(); + } + }; +} + +impl_vmstate_pointer!(*const T where T: VMState); +impl_vmstate_pointer!(*mut T where T: VMState); +impl_vmstate_pointer!(NonNull<T> where T: VMState); +impl_vmstate_pointer!(Option<NonNull<T>> where T: VMState); + +// Arrays using the underlying type's VMState plus +// VMS_ARRAY/VMS_ARRAY_OF_POINTER + +unsafe impl<T: VMState, const N: usize> VMState for [T; N] { + const SCALAR_TYPE: VMStateFieldType = <T as VMState>::SCALAR_TYPE; + const BASE: VMStateField = <T as VMState>::BASE.with_array_flag(N); } #[doc(alias = "VMSTATE_UNUSED_BUFFER")] -- 2.47.1