KVM: arm64: Fix hyp_trace clock disabling

Fix the disable path in hyp_trace_clock_enable(), which fell through to
re-initialize and reschedule the clock after cancelling the work. Return
early instead.

While at it, cleanup hyp_trace_clock::lock which is unused and
hyp_trace_clock::running which is redundant: the trace_remote framework
already serializes calls to the callback enable_tracing.

Fixes: b22888917f ("KVM: arm64: Sync boot clock with the nVHE/pKVM hyp")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev> (✓ DKIM/linux.dev)
Link: https://patch.msgid.link/20260715105100.3178255-1-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Vincent Donnefort
2026-07-15 11:51:00 +01:00
committed by Marc Zyngier
parent 21f12496fd
commit bbece712cf

View File

@@ -37,8 +37,6 @@ static struct hyp_trace_clock {
u32 shift;
struct delayed_work work;
struct completion ready;
struct mutex lock;
bool running;
} hyp_clock;
static void __hyp_clock_work(struct work_struct *work)
@@ -110,12 +108,9 @@ static void hyp_trace_clock_enable(struct hyp_trace_clock *hyp_clock, bool enabl
{
struct system_time_snapshot snap;
if (hyp_clock->running == enable)
return;
if (!enable) {
cancel_delayed_work_sync(&hyp_clock->work);
hyp_clock->running = false;
return;
}
ktime_get_snapshot_id(CLOCK_BOOTTIME, &snap);
@@ -128,7 +123,6 @@ static void hyp_trace_clock_enable(struct hyp_trace_clock *hyp_clock, bool enabl
INIT_DELAYED_WORK(&hyp_clock->work, __hyp_clock_work);
schedule_delayed_work(&hyp_clock->work, msecs_to_jiffies(CLOCK_INIT_MS));
wait_for_completion(&hyp_clock->ready);
hyp_clock->running = true;
}
/* Access to this struct within the trace_remote_callbacks are protected by the trace_remote lock */
@@ -304,9 +298,15 @@ static void hyp_trace_unload(struct trace_buffer_desc *desc, void *priv)
static int hyp_trace_enable_tracing(bool enable, void *priv)
{
int ret;
hyp_trace_clock_enable(&hyp_clock, enable);
return kvm_call_hyp_nvhe(__tracing_enable, enable);
ret = kvm_call_hyp_nvhe(__tracing_enable, enable);
if (ret)
hyp_trace_clock_enable(&hyp_clock, !enable);
return ret;
}
static int hyp_trace_swap_reader_page(unsigned int cpu, void *priv)