missing_const_for_fn is not necessarily useful or good. For example in
a private API you can always add const later, and in a public API
it can be unnecessarily restrictive to annotate everything with const
(blocking further improvements to the API).
Nevertheless, QEMU turns it on because qemu_api uses const quite
aggressively and therefore it can be handy to have as much as possible
annotated with const. Outside qemu_api though, not so much: devices
are self contained consumers and if there is nothing that could use
their functions in const contexts that were not anticipated.
Since missing_const_for_fn can be a bit noisy and trigger on trivial
functions that no one would ever call in const context, do not
turn it on everywhere and only keep it in qemu_api as a special case.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Being the first crate added to QEMU, pl011 has a rather restrictive
Clippy setup. This can be sometimes a bit too heavy on its suggestions,
for example
error: this could be a `const fn`
--> hw/char/pl011/src/device.rs:382:5
|
382 | / fn set_read_trigger(&mut self) {
383 | | self.read_trigger = 1;
384 | | }
| |_____^
Just use the standard set that is present in rust/Cargo.toml, with
just a small adjustment to allow upper case acronyms which are used
for register names.
Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Configure the minimum supported Rust version (though strictly speaking
that's redundant with Cargo.toml), and the list of CamelCase identifiers
that are not Rust types.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some items of Cargo.toml (readme, homepage, repository) are
only present because of clippy::cargo warnings being enabled in
rust/hw/char/pl011/src/lib.rs. But these items are not
particularly useful and would be all the same for all Cargo.toml
files in the QEMU workspace. Clean them up.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The `const_zero` crate provides a nice macro to zero type-specific
constants, which doesn't need to enumerates the fields one by one.
Introduce the `const_zero` macro to QEMU (along with its documentation), and
use it to simplify the implementation of `Zeroable` trait.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250123163143.679841-1-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Because register reset is within a borrow_mut() call, reset
does not need anymore a mut reference to the PL011State.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unify the "Interrupt" enum and the "INT_*" constants with a struct
that contains the bits. The "int_level" and "int_enabled" fields
could use a crate such as "bitflags".
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is a step towards making memory ops use a shared reference to the
device type; it's not yet possible due to the calls to character device
functions.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull all the mutable fields of PL011State into a separate struct.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu_irqs are not part of the vmstate, therefore they will remain in
PL011State. Update them if needed after regs_read()/regs_write().
Apply #[must_use] to functions that return whether the interrupt state
could have changed, so that it's harder to forget the call to update().
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Prepare for moving all references to the registers and the FIFO into a
separate struct.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As an added bonus, this also makes the new function return u32 instead
of u64, thus factoring some casts into a single place.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The only public interfaces for pl011 are TYPE_PL011 and pl011_create.
Remove pub from everything else.
Note: the "allow(dead_code)" is removed later.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do not use new_unchecked; the effect is the same, but the
code is easier to read and unsafe regions become smaller.
Likewise, NonNull::new can be used instead of assertion and
followed by as_ref() or as_mut() instead of dereferencing the
pointer.
Suggested-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>
List all the necessary bindings to better identify gaps in rust/qapi.
And include the bindings wrapped by rust/qapi instead mapping the raw
bindings directly.
Inspired-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250121140457.84631-3-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A safe REALIZE accepts immutable reference.
Since current PL011's realize() only calls a char binding function (
qemu_chr_fe_set_handlers), it is possible to convert mutable reference
(&mut self) to immutable reference (&self), which only needs to convert
the pointers passed to C to mutable pointers.
Thus, make REALIZE accept immutable reference.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250121140457.84631-2-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The ObjectDeref trait now provides all the magic that is required to fake
inheritance. Replace the "impl SysBusDevice" block of qemu_api::sysbus
with a trait, so that sysbus_init_irq() can be invoked as "self.init_irq()"
without any intermediate upcast.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is going to be fairly common. Using a custom procedural macro
provides better error messages and automatically finds the right
type.
Note that this is different from the same-named macro in the
derive_more crate. That one provides conversion from e.g. tuples
to enums with tuple variants, not from integers to enums.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Generalize the CompileError tuple to an enum, that can be either an error
message or a parse error from syn.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Leave IRQ and MMIO initialization to instance_post_init. In Rust the
two callbacks are more distinct, because only instance_post_init has a
fully initialized object available.
While at it, add a wrapper for sysbus_init_mmio so that accesses to
the SysBusDevice correctly use shared references.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is no need to monkeypatch DeviceId::Luminary into the already-initialized
PL011State. Instead, now that we can define a class hierarchy, we can define
PL011Class and make device_id a field in there.
There is also no need anymore to have "Arm" as zero, so change DeviceId into a
wrapper for the array; all it does is provide an Index<hwaddr> implementation
because arrays can only be indexed by usize.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace the customizable INSTANCE_FINALIZE with a generic function
that drops the Rust object.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert derive_object to the same pattern of first making a
Result<proc_macro2::TokenStream, CompileError>, and then doing
.unwrap_or_else(Into::into) to support checking the validity of
the input. Add is_c_repr to check that all QOM structs include
a #[repr(C)] attribute.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is relatively common in the low-level qemu_api code to assert that
a field of a struct has a specific type; for example, it can be used
to ensure that the fields match what the qemu_api and C code expects
for safety.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a type that, together with the C function object_deinit, ensures the
correct drop order for QOM objects relative to their superclasses.
Right now it is not possible to implement the Drop trait for QOM classes
that are defined in Rust, as the drop() function would not be called when
the object goes away; instead what is called is ObjectImpl::INSTANCE_FINALIZE.
It would be nice for INSTANCE_FINALIZE to just drop the object, but this has
a problem: suppose you have
pub struct MySuperclass {
parent: DeviceState,
field: Box<MyData>,
...
}
impl Drop for MySuperclass {
...
}
pub struct MySubclass {
parent: MySuperclass,
...
}
and an instance_finalize implementation that is like
unsafe extern "C" fn drop_object<T: ObjectImpl>(obj: *mut Object) {
unsafe { std::ptr::drop_in_place(obj.cast::<T>()) }
}
When instance_finalize is called for MySubclass, it will walk the struct's
list of fields and call the drop method for MySuperclass. Then, object_deinit
recurses to the superclass and calls the same drop method again. This
will cause double-freeing of the Box<Data>.
What's happening here is that QOM wants to control the drop order of
MySuperclass and MySubclass's fields. To do so, the parent field must
be marked ManuallyDrop<>, which is quite ugly. Instead, add a wrapper
type ParentField<> that is specific to QOM. This hides the implementation
detail of *what* is special about the ParentField, and will also be easy
to check in the #[derive(Object)] macro.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
--feature is an option for cargo but not for rustc.
Reported-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Bernhard Beschow <shentey@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Headers in include/sysemu/ are not only related to system
*emulation*, they are also used by virtualization. Rename
as system/ which is clearer.
Files renamed manually then mechanical change using sed tool.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Lei Yang <leiyang@redhat.com>
Message-Id: <20241203172445.28576-1-philmd@linaro.org>
Use ==/!= instead of going through bool and xor.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
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>
The PL011 Technical Reference Manual lists the "real" size of the
registers in table 3-1, and only rounds up to the next byte when
describing the registers; for example, UARTDR is listed as having
width 12/8 (12 bits read, 8 written) and only bits 15:0 are listed
in "Table 3-2 UARTDR Register".
However, in practice these are 32-bit registers, accessible only
through 32-bit MMIO accesses; preserving the fiction that they're
smaller introduces multiple casts (to go from the bilge bitfield
type to e.g u16 to u64) and more importantly it breaks the
migration stream because the Rust vmstate macros are not yet
type safe.
So, just make everything 32-bits wide.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Data struct is wrong, and does not show how bits 8-15 of DR
are the receive status. Fix it, and use it to fix break
errors ("c >> 8" in the C code does not translate to
"c.to_be_bytes()[3]").
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
