Commit graph

130 commits

Author SHA1 Message Date
Zhao Liu
42c814b139 rust/vmstate: Fix "cannot infer type" error in vmstate_struct
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>
2025-03-21 12:56:00 +01:00
Zhao Liu
618258256e rust/vmstate: Fix type check for varray in vmstate_struct
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>
2025-03-21 12:56:00 +01:00
Zhao Liu
20797069c7 rust/vmstate: Fix size field of VMStateField with VMS_ARRAY_OF_POINTER flag
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>
2025-03-21 12:56:00 +01:00
Zhao Liu
c3d80af5ec rust/vmstate: Fix num field when varray flags are set
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>
2025-03-21 12:56:00 +01:00
Zhao Liu
6ca5c3bedf rust/vmstate: Fix num_offset in vmstate macros
`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>
2025-03-21 12:56:00 +01:00
Zhao Liu
ea8a7ceba3 rust/vmstate: Remove unnecessary unsafe
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>
2025-03-21 12:56:00 +01:00
Paolo Bonzini
9d116f42a3 rust: assertions: add static_assert
Add a new assertion that is similar to "const { assert!(...) }" but can be used
outside functions and with older versions of Rust.  A similar macro is found in
Linux, whereas the "static_assertions" crate has a const_assert macro that
produces worse error messages.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Link: https://lore.kernel.org/r/20250321112523.1774131-2-peter.maydell@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-21 12:51:16 +01:00
Paolo Bonzini
094cd35913 rust: qom: remove operations on &mut
The dubious casts of mutable references to objects are not used
anymore: the wrappers for qdev_init_clock_in and for IRQ and MMIO
initialization can be called directly on the subclasses, without
casts, plus they take a shared reference so they can just use
"upcast()" instead of "upcast_mut()".  Remove them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
5778ce9997 rust: cell: add full example of declaring a SysBusDevice
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
2d0050cbe2 rust: chardev: provide basic bindings to character devices
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>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
2ad011d466 rust: bindings: remove more unnecessary Send/Sync impls
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>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
48627510a7 rust: chardev: wrap Chardev with Opaque<>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
af0868cba3 rust: memory: wrap MemoryRegion with Opaque<>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
f4751c7a42 rust: sysbus: wrap SysBusDevice with Opaque<>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
09fda8f5dc rust: hpet: do not access fields of SysBusDevice
Fields of SysBusDevice must only be accessed with the BQL taken.  Add
a wrapper that verifies that.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
fc22d650d5 rust: qdev: wrap Clock and DeviceState with Opaque<>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:47 +01:00
Paolo Bonzini
7fb4a99df1 rust: qom: wrap Object with Opaque<>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:46 +01:00
Paolo Bonzini
9c9a6a889c rust: irq: wrap IRQState with Opaque<>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:46 +01:00
Paolo Bonzini
a32b239699 rust: timer: wrap QEMUTimer with Opaque<> and express pinning requirements
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>
2025-03-06 12:44:46 +01:00
Paolo Bonzini
d7f5ae8b30 rust: vmstate: add std::pin::Pin as transparent wrapper
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-06 12:44:46 +01:00
Paolo Bonzini
f07a5674cf rust: qemu_api_macros: add Wrapper derive macro
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>
2025-03-06 12:44:46 +01:00
Paolo Bonzini
0b9d05e3c9 rust: cell: add wrapper for FFI types
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>
2025-03-06 12:44:46 +01:00
Paolo Bonzini
d556226d69 rust: qom: get rid of ClassInitImpl
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>
2025-02-25 16:18:12 +01:00
Paolo Bonzini
567c0c41a6 rust: pl011, qemu_api tests: do not use ClassInitImpl
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>
2025-02-25 16:18:12 +01:00
Paolo Bonzini
4551f342fe rust: qom: add ObjectImpl::CLASS_INIT
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>
2025-02-25 16:18:12 +01:00
Paolo Bonzini
3212da0033 rust: add SysBusDeviceImpl
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>
2025-02-25 16:18:12 +01:00
Paolo Bonzini
ac5699c5da rust: add IsA bounds to QOM implementation traits
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>
2025-02-25 16:18:12 +01:00
Zhao Liu
c48700e86d rust: prefer importing std::ptr over core::ptr
The std::ptr is same as core::ptr, but std has already been used in many
cases and there's no need to choose non-std library.

So, use std::ptr directly to make the used ptr library as consistent as
possible.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250218080835.3341082-1-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-25 16:18:11 +01:00
Paolo Bonzini
4cb7040d85 rust: tests: do not import bindings::*
Similar to the devices, spell the exact set of C functions that are
called directly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-25 16:18:11 +01:00
Paolo Bonzini
8a420dd109 rust: add module to convert between success/-errno and io::Result
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>
2025-02-25 16:18:08 +01:00
Paolo Bonzini
4cfe9edb1b rust: subprojects: add libc crate
This allows access to errno values.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-25 10:49:23 +01:00
Paolo Bonzini
16534af51b rust: fix doctests
Doctests were not being run by CI, and have broken. Fix them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 13:50:43 +01:00
Paolo Bonzini
ee7d3aec54 rust: vmstate: remove redundant link targets
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Paolo Bonzini
ebacd14a6f rust: qemu_api: add a documentation header for all modules
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Zhao Liu
0534248a6b rust/timer/hpet: define hpet_fw_cfg
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>
2025-02-13 12:51:34 +01:00
Zhao Liu
eadb83f9a3 rust: add bindings for timer
Add timer bindings to help handle idiomatic Rust callbacks.

Additionally, wrap QEMUClockType in ClockType binding to avoid unsafe
calls in device code.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-7-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Zhao Liu
d015d4cbb4 rust: add bindings for memattrs
The MemTxAttrs structure contains bitfield members, and bindgen is
unable to generate an equivalent macro definition for
MEMTXATTRS_UNSPECIFIED.

Therefore, manually define a global constant variable
MEMTXATTRS_UNSPECIFIED to support calls from Rust code.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250125125137.1223277-6-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Zhao Liu
9a96d41007 rust: add bindings for gpio_{in|out} initialization
Wrap qdev_init_gpio_{in|out} as methods in DeviceMethods. And for
qdev_init_gpio_in, based on FnCall, it can support idiomatic Rust
callback without the need for C style wrapper.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-5-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Zhao Liu
e6f1195f55 rust/irq: Add a helper to convert [InterruptSource] to pointer
This is useful when taking an InterruptSource slice and passing it to C
function.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-4-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Zhao Liu
7f2d4181a3 rust/qdev: add the macro to define bit property
HPET device (Rust device) needs to define the bit type property.

Add a variant of define_property macro to define bit type property.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-3-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:51:34 +01:00
Paolo Bonzini
7630ca2a70 rust: pl011: convert pl011_create to safe Rust
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>
2025-02-13 12:19:34 +01:00
Paolo Bonzini
a22bd55ffd rust: chardev, qdev: add bindings to qdev_prop_set_chr
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>
2025-02-13 12:19:34 +01:00
Paolo Bonzini
61faf6ac7b rust: irq: define ObjectType for IRQState
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>
2025-02-13 12:19:34 +01:00
Paolo Bonzini
590faa03ee rust: bindings for MemoryRegionOps
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:19:34 +01:00
Paolo Bonzini
d449d29a99 rust: bindings: add Send and Sync markers for types that have bindings
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>
2025-02-13 12:19:34 +01:00
Paolo Bonzini
5472a38cb9 rust: qdev: switch from legacy reset to Resettable
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-13 12:19:34 +01:00
Paolo Bonzini
68da5402df rust: qdev: make ObjectImpl a supertrait of DeviceImpl
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>
2025-02-13 12:19:33 +01:00
Paolo Bonzini
688c674158 rust: qom: allow initializing interface vtables
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>
2025-02-13 12:19:33 +01:00
Paolo Bonzini
201ef001dd rust: qdev: add clock creation
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>
2025-02-13 12:19:33 +01:00
Paolo Bonzini
66bcc554d2 rust: callbacks: allow passing optional callbacks as ()
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>
2025-02-13 12:19:33 +01:00