Nested offset_of was stabilized in Rust 1.82. Since the minimum
supported version for QEMU is 1.83, allow nested field accesses
in vmstate_of!
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Return a Result<()> from the method, and "unwrap" it into error_fatal
in the caller.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a simpler function that hides the creation of the Error**.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This simplifies conversions, making it possible to convert any error
into a QEMU util::Error with ".into()" (and therefore with "?").
The cost is having a separate constructor for when the error is a simple
string, but that is made easier by the ensure! macro. If necessary,
another macro similar to "anyhow!" can be returned, but for now there
is no need for that.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The macro is similar to anyhow::ensure but uses QEMU's variation
on anyhow::Error. It can be used to easily check a condition
and format an error message.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The common superclass for devices could have its own migration state;
for it to be included in the subclass's VMState, ParentField<> must
implement the VMState trait.
Reported-by: Chen Miao <chenmiao@openatom.club>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The definition of types needed for g_autolist(), g_autoslist(),
g_autoqueue() need the imports for GList, GSList and GQueue
to appear everything. Rust code is never going to see those,
since they are not used in structs. Block the types from
appearing in the bindings.
Co-authored-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is most likely desirable, and is the easiest way to migrate
a bit-sized value without peeking at the innards of the bilge crate.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a macro that recursively builds the "migrated" version
of a struct.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Instead of dealing with pre/post callbacks, allow devices to
implement a snapshot/restore mechanism; this has two main
advantages:
- it can be easily implemented via procedural macros
- there can be generic implementations to deal with various
kinds of interior-mutable containers, from BqlRefCell to Mutex,
so that C code does not see Rust concepts such as Mutex<>.
Using it is easy; you can implement the snapshot/restore trait
ToMigrationState and declare your state like:
regs: Migratable<Mutex<MyDeviceRegisters>>
Migratable<> allows dereferencing to the underlying object with
no run-time cost.
Note that Migratable<> actually does not accept ToMigrationState,
only the similar ToMigrationStateShared trait that the user will mostly
not care about. This is required by the fact that pre/post callbacks
take a &self, and ensures that the argument is a Mutex or BqlRefCell
(including an array or Arc<> thereof).
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The high-level wrapper Migratable<T> will contain a BqlCell,
which would introduce a circular dependency betwen the bql and
migration crates. Move the implementation of VMState for cells
to "migration", together with the implementation for std types.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is useful when building a VMState for generic structs, because you have
to avoid nested statics. Using vmstate_fields! will fail in the likely case
where the _FIELDS static uses Self from an outer item, because that is
forbidden.
The separate macros are needed because you cannot just do
.fields(vmstate_fields_ref! {
vmstate_of!(PL011State, clock),
})
The value returned by vmstate_fields_ref! is not promoted to static, which is
unfortunate but intentional (https://github.com/rust-lang/rust/issues/60502):
error[E0716]: temporary value dropped while borrowed
--> rust/hw/char/pl011/libpl011.rlib.p/structured/device.rs:743:17
|
738 | / VMStateDescriptionBuilder::<PL011State>::new()
739 | | .name(c"pl011/clock")
740 | | .version_id(1)
741 | | .minimum_version_id(1)
742 | | .needed(&PL011State::clock_needed)
743 | | .fields(vmstate_fields_ref! {
| | _________________^
744 | || vmstate_of!(PL011State, clock),
745 | || })
| ||_________^- argument requires that borrow lasts for `'static`
| |_________|
| creates a temporary value which is freed while still in use
746 | .build();
| - temporary value is freed at the end of this statement
Thus it is necessary to use the "static", whether explicitly or hidden by
vmstate_fields.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For consistency with fields(), validate the value (at least to some extent)
before passing it to C.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Raw pointers were used to insert a NULL one at the end of the array.
However, Option<&...> has the same layout and does not remove Sync
from the type of the array.
As an extra benefit, this enables validation of the terminator of the
subsection array, because is_null() in const context would not be stable
until Rust 1.84.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pass a slice instead; a function that accepts a raw pointer should
arguably be declared as unsafe.
But since it is now much easier to forget vmstate_fields!, validate the
value (at least to some extent) before passing it to C. (Unfortunately,
doing the same for subsections would require const ptr::is_null(), which
is only stable in Rust 1.84).
Suggested-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This method is rarely useful in QEMU due to the pervasiveness of
shared references, but add it for when a &mut BqlRefCell<> is used.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HPET ids for fw_cfg are not assigned correctly, because there
is a read but no write. This is caught by nightly Rust as
an unused-assignments warning, so fix it.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The call_func_with_field! macro uses dead code willingly to infer
the appropriate type. This has started adding a new warning:
error: unused variable: `value__`
79 | break phantom__(&{ let value__: $typ; value__.$($field).+ })
So shut it up together with the existing unreachable_code warning.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Newer versions of clippy are able to see that all the variants in
the PL011 word length enum end with "Bits", and complain about it.
Allow it.
Reported-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
