Commit graph

3 commits

Author SHA1 Message Date
Zhao Liu
8d9502b4e9 rust/timer: Define NANOSECONDS_PER_SECOND binding as u64
NANOSECONDS_PER_SECOND is often used in operations with get_ns(), which
currently returns a u64.

Therefore, define a new NANOSECONDS_PER_SECOND binding is with u64 type
to eliminate unnecessary type conversions (from u32 to u64).

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250414144943.1112885-6-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-05-02 17:37:46 +02:00
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
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