Most of the character device API is pretty simple, with "0 or -errno"
or "number of bytes or -errno" as the convention for return codes.
Add safe wrappers for the API to the CharBackend bindgen-generated
struct.
The API is not complete, but it covers the parts that are used
by the PL011 device, plus qemu_chr_fe_write which is needed to
implement the standard library Write trait.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Send and Sync are now implemented on the opaque wrappers. Remove them
from the bindings module, unless the structs are pure data containers
and/or have no C functions defined on them.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Timers must be pinned in memory, because modify() stores a pointer to them
in the TimerList. To express this requirement, change init_full() to take
a pinned reference. Because the only way to obtain a Timer is through
Timer::new(), which is unsafe, modify() can assume that the timer it got
was later initialized; and because the initialization takes a Pin<&mut
Timer> modify() can assume that the timer is pinned. In the future the
pinning requirement will be expressed through the pin_init crate instead.
Note that Timer is a bit different from other users of Opaque, in that
it is created in Rust code rather than C code. This is why it has to
use the unsafe constructors provided by Opaque; and in fact Timer::new()
is also unsafe, because it leaves it to the caller to invoke init_full()
before modify(). Without a call to init_full(), modify() will cause a
NULL pointer dereference.
An alternative could be to combine new() + init_full() by returning a
pinned box; however, using a reference makes it easier to express
the requirement that the opaque outlives the timer.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This simplifies things for migration, since Option<Box<QEMUTimer>> does not
implement VMState.
This also shows a soundness issue because Timer::new() will leave a NULL
timer list pointer, which can then be dereferenced by Timer::modify(). It
will be fixed shortly.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a derive macro that makes it easy to peel off all the layers of
specialness (UnsafeCell, MaybeUninit, etc.) and just get a pointer
to the wrapped type; and likewise add them back starting from a
*mut.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Inspired by the same-named type in Linux. This type provides the compiler
with a correct view of what goes on with FFI types. In addition, it
separates the glue code from the bindgen-generated code, allowing
traits such as Send, Sync or Zeroable to be specified independently
for C and Rust structs.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Complete the conversion from the ClassInitImpl trait to class_init() methods.
This will provide more freedom to split the qemu_api crate in separate parts.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Outside the qemu_api crate, orphan rules make the usage of ClassInitImpl
unwieldy. Now that it is optional, do not use it.
For PL011Class, this makes it easier to provide a PL011Impl trait similar
to the ones in the qemu_api crate. The device id consts are moved there.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As shown in the PL011 device, the orphan rules required a manual
implementation of ClassInitImpl for anything not in the qemu_api crate;
this gets in the way of moving system emulation-specific code (including
DeviceClass, which as a blanket ClassInitImpl<DeviceClass> implementation)
into its own crate.
Make ClassInitImpl optional, at the cost of having to specify the CLASS_INIT
member by hand in every implementation of ObjectImpl. The next commits will
get rid of it, replacing all the "impl<T> ClassInitImpl<Class> for T" blocks
with a generic class_init<T> method on Class.
Right now the definition is always the same, but do not provide a default
as that will not be true once ClassInitImpl goes away.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The only function, right now, is to ensure that anything with a
SysBusDeviceClass class is a SysBusDevice.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Check that the right bounds are provided to the qom_isa! macro
whenever the class is defined to implement a certain class.
This removes the need to add IsA<> bounds together with the
*Impl trait bounds.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is a common convention in QEMU to return a positive value in case of
success, and a negated errno value in case of error. Unfortunately,
using errno portably in Rust is a bit complicated; on Unix the errno
values are supported natively by io::Error, but on Windows they are not;
so, use the libc crate.
This is a set of utility functions that are used by both chardev and
block layer bindings.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add the HPETTimer and HPETState (HPET timer block), along with their
basic methods and register definitions.
This is in preparation for supporting the QAPI interfaces.
Note, wrap all items in HPETState that may be changed in the callback
called by C code into the BqlCell/BqlRefCell.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-9-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Define HPETFwEntry structure with the same memory layout as
hpet_fw_entry in C.
Further, define the global hpet_cfg variable in Rust which is the
same as the C version. This hpet_cfg variable in Rust will replace
the C version one and allows both Rust code and C code to access it.
The Rust version of hpet_cfg is self-contained, avoiding unsafe
access to C code.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-8-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Not a major change but, as a small but significant step in creating
qdev bindings, show how pl011_create can be written without "unsafe"
calls (apart from converting pointers to references).
This also provides a starting point for creating Error** bindings.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Because the argument to the function is an Owned<Chardev>, this also
adds an ObjectType implementation to Chardev.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is a small preparation in order to use an Owned<IRQState> for the argument
to sysbus_connect_irq.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is needed for the MemoryRegionOps<T> to be declared as static;
Rust requires static elements to be Sync.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In practice it has to be implemented always in order to access an
implementation of ClassInitImpl<ObjectClass>. Make the relationship
explicit in the code.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unlike regular classes, interface vtables can only be obtained via
object_class_dynamic_cast. Provide a wrapper that allows accessing
the vtable and pass it to a ClassInitImpl implementation, for example
ClassInitImpl<ResettableClass>.
Reviewed-by: Zhao Liu <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>
In some cases, callbacks are optional. Using "Some(function)" and "None"
does not work well, because when someone writes "None" the compiler does
not know what to use for "F" in "Option<F>".
Therefore, adopt () to mean a "null" callback. It is possible to enforce
that a callback is valid by adding a "let _: () = F::ASSERT_IS_SOME" before
the invocation of F::call.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The basic object lifecycle test can now be implemented using safe code!
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>
