On 10/12/26 16:52, Alex Bennée wrote:
diff --git a/target/arm/tcg/op_helper.c b/target/arm/tcg/op_helper.c
index af56eff9f18..7c1fdab79d7 100644
--- a/target/arm/tcg/op_helper.c
+++ b/target/arm/tcg/op_helper.c
@@ -471,6 +471,9 @@ void HELPER(wfit)(CPUARMState *env, uint32_t rd)
void HELPER(sev)(CPUARMState *env)
{
CPUState *cs = env_cpu(env);
+
+ BQL_LOCK_GUARD();
+
CPU_FOREACH(cs) {
ARMCPU *target_cpu = ARM_CPU(cs);
target_cpu->env.event_register = true;
Reviewed-by: Paolo Bonzini <[email protected]>
The use of cmpxchg in wfxt_timer_cb is fishy though.
Clearing HALT_WFE should be the task of the target CPU, not the timer.
The timer_mod() should be *after* halt_reason(*), and then you can just
do a qatomic_read() instead of a cmpxchg(**) in wfxt_timer_cb().
However, I don't understand at all why wfxt_timer_cb needs to set
event_register to true. It seems to me that a wfet + wfe sequence,
where the first wfet times out, *should* halt again on the second wfe;
but as the code is written it doesn't.
I think wfxt_timer_cb only needs to call cpu_interrupt().
Thanks,
Paolo
(*) always, even if the halt reason is not HALT_WFE, if only for consistency
(**) you don't need a lock or acquire/release here, because the timer
callback always sees everything that happened before timer_mod(). In a
sense, timer_mod() *is* the release operation and starting the callback
is the acquire operation.
