These typos are found by "cargo spellcheck". Though it outputs a lot of
noise and false positives, there still are some real typos.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250520152750.2542612-6-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is allowed since Rust 1.64.0.
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make vmstate_struct and vmstate_clock more similar; they are basically the
same thing, except for the clock case having a built-in VMStateDescription.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unfortunately, at present it's not possible to have a const
"with_exist_check" method to append test_fn after vmstate_struct (due
to error on "constant functions cannot evaluate destructors" for `F`).
Before the vmstate builder, the only way to support "test_fn" is to
extend vmstate_struct macro to add the such new optional member (and
fortunately, Rust can still parse the current expansion!).
Abstract the previous callback implementation of vmstate_validate into
a separate macro, and moves it before vmstate_struct for vmstate_struct
to call.
Note that there's no need to add any extra flag for a new test_fn added
in the VMStateField.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250414144943.1112885-2-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The use of "bindings::*" masks incomplete path of VMStateFlags.
Include complete crate path of VMStateFlags in vmstate_clock, and clean
up "bindings::*" in device_class.rs of pl011.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-16-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In C version, VMSTATE_VALIDATE accepts the function pointer, which is
used to check if some conditions of structure could meet, although the
C version macro doesn't accept any structure as the opaque type.
But it's hard to integrate VMSTATE_VALIDAE into vmstate_struct, a new
macro has to be introduced to specifically handle the case corresponding
to VMSTATE_VALIDATE.
One of the difficulties is inferring the type of a callback by its name
`test_fn`. We can't directly use `test_fn` as a parameter of
test_cb_builder__() to get its type "F", because in this way, Rust
compiler will be too conservative on drop check and complain "the
destructor for this type cannot be evaluated in constant functions".
Fortunately, PhantomData<T> could help in this case, because it is
considered to never have a destructor, no matter its field type [*].
The `phantom__()` in the `call_func_with_field` macro provides a good
example of using PhantomData to infer type. So copy this idea and apply
it to the `vmstate_validate` macro.
[*]: https://doc.rust-lang.org/std/ops/trait.Drop.html#drop-check
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-11-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
At present, Rust side has a timer binding "timer::Timer", so the vmstate
for timer should base on that binding instead of the raw
"binding::QEMUTimer".
It's possible to apply impl_vmstate_transparent for cell::Opaque and
then impl_vmstate_forward for timer::Timer. But binding::QEMUTimer
shouldn't be used directly, so that vmstate for such raw timer type is
useless.
Thus, apply impl_vmstate_scalar for timer::Timer. And since Opaque<> is
useful, apply impl_vmstate_transparent for cell::Opaque as well.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-10-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The varry of structure created by vmstate_struct is different with
vmstate_of. This is because vmstate_struct uses the `vmsd` to traverse
the vmstates of structure's fields, rather than treating the structure
directly as a well-defined vmstate.
Therefore, there's no need to check array flag when building varray by
vmstate_struct.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-9-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The VMState type bound is not used in with_varray_flag().
And for vmstate_struct, Rust cannot infer the type of `num` from the
call_func_with_field(), so this causes the compiling error because it
complains "cannot satisfy `_: VMState`" in with_varray_flag().
Note Rust can infer the type in vmstate_of macro so that
with_varray_flag() can work at there. It is possible that the different
initialization ways in the two macros cause differences in Rust's
type inference.
But in fact, the VMState type bound is not used in with_varray_flag()
and vmstate_varray_flag() has already checked the VMState type, it's
safe to drop VMState bound of with_varray_flag(), which can fix the
above compiling error.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-8-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rust cannot infer the type (it should be VMStateField) after
Zeroable::ZERO, which cause the compiling error.
To fix this error, call with_varray_flag() after VMStateField's
initialization.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-7-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When pass a varray to vmstate_struct, the `type` parameter should be the
type of the element in the varray, for example:
vmstate_struct!(HPETState, timers, [0 .. num_timers], VMSTATE_HPET_TIMER,
BqlRefCell<HPETTimer>).with_version_id(0)
But this breaks current type check, because it checks the type of
`field`, which is an array type (for the above example, type of timers
is [BqlRefCell<HPETTimer>; 32], not BqlRefCell<HPETTimer>).
But the current assert_field_type() can no longer be extended to include
new arguments, so a variant of it (a second macro containing the
`num = $num:ident` parameter) had to be added to handle array cases.
In this new macro, it not only checks the type of element, but also
checks whether the `num` (number of elements in varray) is out of range.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-6-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The `size` field of the VMStateField with VMS_ARRAY_OF_POINTER flag
should stores the size of pointer, which depends on platform.
Currently, `*const`, `*mut`, `NonNull`, `Box<>` and their wrapper are
supported, and they have the same size as `usize`.
Store the size (of `usize`) when VMS_ARRAY_OF_POINTER flag is set.
The size may be changed when more smart pointers are supported, but now
the size of "usize" is enough.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-5-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Array type vmstate has the VMStateField with `num` equals its length.
When the varray vmstate is built based a array type, the `num` field
should be cleaned to 0, because varray uses `num_offset` instead of
`num` to store elements number information.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-4-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
`num_offset` is a member of `VMStateField`, and there's no need to use
"." to access this field in a `VMStateField` instance.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-3-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove the `unsafe` block of vmsd, because vmsd (passed to
vmstate_struct) is defined in Rust side now, and it doesn't need
`unsafe`.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250318130219.1799170-2-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a Rust version of qdev_init_clock_in, which can be used in
instance_init. There are a couple differences with the C
version:
- in Rust the object keeps its own reference to the clock (in addition to
the one embedded in the NamedClockList), and the reference is dropped
automatically by instance_finalize(); this is encoded in the signature
of DeviceClassMethods::init_clock_in, which makes the lifetime of the
clock independent of that of the object it holds. This goes unnoticed
in the C version and is due to the existence of aliases.
- also, anything that happens during instance_init uses the pinned_init
framework to operate on a partially initialized object, and is done
through class methods (i.e. through DeviceClassMethods rather than
DeviceMethods) because the device does not exist yet. Therefore, Rust
code *must* create clocks from instance_init, which is stricter than C.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a smart pointer that allows to add and remove references from
QOM objects. It's important to note that while all QOM objects have a
reference count, in practice not all of them have their lifetime guarded
by it. Embedded objects, specifically, are confined to the lifetime of
the owner.
When writing Rust bindings this is important, because embedded objects are
*never* used through the "Owned<>" smart pointer that is introduced here.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Keep vmstate_clock!; because it uses a field of type VMStateDescription,
it cannot be converted to the VMState trait without access to the
const_refs_static feature.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is not type safe, but it's the best that can be done without
const_refs_static. It can also be used with BqlCell and BqlRefCell.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Scalar types are those that have their own VMStateInfo. This poses
a problem in that references to VMStateInfo can only be included in
associated consts starting with Rust 1.83.0, when the const_refs_static
was stabilized. Removing the requirement is done by placing a limited
list of VMStateInfos in an enum, and going from enum to &VMStateInfo
only when building the VMStateField.
The same thing cannot be done with VMS_STRUCT because the set of
VMStateDescriptions extends to structs defined by the devices.
Therefore, structs and cells cannot yet use vmstate_of!.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This shortens a bit the constants. Do not bother using it
in the vmstate macros since most of them will go away soon.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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 <pbonzini@redhat.com>
The existing translation of the C macros for vmstate does not make
any attempt to type-check vmstate declarations against the struct, so
introduce a new system that computes VMStateField based on the actual
struct declaration.
Macros do not have full access to the type system, therefore a full
implementation of this scheme requires a helper trait to analyze the
type and produce a VMStateField from it; a macro "vmstate_of!" accepts
arguments similar to "offset_of!" and tricks the compiler into looking
up the trait for the right type.
The patch introduces not just vmstate_of!, but also the slightly too
clever enabling macro call_func_with_field!. The particular trick used
here was proposed on the users.rust-lang.org forum, so I take no merit
and all the blame.
Introduce the trait and some functions to access it; the actual
implementation comes later.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Rust vmstate macros lack the type-safety of their C equivalents (so
safe, much abstraction), and therefore they were predictably wrong.
The registers have already been changed to 32-bits in the previous patch,
but read_pos/read_count/read_trigger also have to be u32 instead of usize.
The easiest way to do so is to let the FIFO use u32 indices instead
of usize.
My plan for making VMStateField typesafe is to have a trait to retrieve
a basic VMStateField; for example something like vmstate_uint32 would
become an implementation of the VMState trait on u32. Then you'd write
something like "vmstate_of!(Type, field).with_version_id(2)". That is,
vmstate_of retrieves the basic VMStateField and fills in the offset,
and then more changes can be applied on top.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Long term we do not want device code to use "bindings" at all, so make it
possible to get the relevant types from the other modules of qemu-api.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
offset_of! was stabilized in Rust 1.77.0. Use an alternative implemenation
that was found on the Rust forums, and whose author agreed to license as
MIT for use in QEMU.
The alternative allows only one level of field access, but apart
from this can be used just by replacing core::mem::offset_of! with
qemu_api::offset_of!.
The actual implementation of offset_of! is done in a declarative macro,
but for simplicity and to avoid introducing an extra level of indentation,
the trigger is a procedural macro #[derive(offsets)].
The procedural macro is perhaps a bit overengineered, but it helps
introducing some idioms that will be useful in the future as well.
Signed-off-by: Junjie Mao <junjie.mao@hotmail.com>
Co-developed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allows CStr constants to be defined easily on Rust 1.63.0, while
checking that there are no embedded NULs. c"" literals were only
stabilized in Rust 1.77.0.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
core::ffi::c_* types were introduced in Rust 1.64.0. Use the older types
in std::os::raw, which are now aliases of the types in core::ffi. There is
no need to compile QEMU as no_std, so this is acceptable as long as we support
a version of Debian with Rust 1.63.0.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a new qemu_api module, `vmstate`. Declare a bunch of Rust
macros declared that are equivalent in spirit to the C macros in
include/migration/vmstate.h.
For example the Rust of equivalent of the C macro:
VMSTATE_UINT32(field_name, struct_name)
is:
vmstate_uint32!(field_name, StructName)
This breathtaking development will allow us to reach feature parity between
the Rust and C pl011 implementations.
Extracted from a patch by Manos Pitsidianakis
(https://lore.kernel.org/qemu-devel/20241024-rust-round-2-v1-4-051e7a25b978@linaro.org/).
Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
