KVM: arm64: Stop the hyp trace clock worker on disable

[PATCH] KVM: arm64: Stop the hyp trace clock worker on disable

Posted by Fuad Tabba 4 days, 6 hours ago

When disabling, hyp_trace_clock_enable() cancels the clock work but then
falls through into the enable path, which re-schedules it and marks the
clock running again, so the worker never stops. Return once the work is
cancelled.

Fixes: b22888917fa41 ("KVM: arm64: Sync boot clock with the nVHE/pKVM hyp")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260720172923.E4F161F000E9@smtp.kernel.org/
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 arch/arm64/kvm/hyp_trace.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
index 2411b4c32932c..27367843fd211 100644
--- a/arch/arm64/kvm/hyp_trace.c
+++ b/arch/arm64/kvm/hyp_trace.c
@@ -116,6 +116,7 @@ static void hyp_trace_clock_enable(struct hyp_trace_clock *hyp_clock, bool enabl
 	if (!enable) {
 		cancel_delayed_work_sync(&hyp_clock->work);
 		hyp_clock->running = false;
+		return;
 	}
 
 	ktime_get_snapshot_id(CLOCK_BOOTTIME, &snap);

base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f
-- 
2.39.5

Re: [PATCH] KVM: arm64: Stop the hyp trace clock worker on disable

Posted by Vincent Donnefort 4 days, 6 hours ago

On Mon, Jul 20, 2026 at 07:48:50PM +0100, Fuad Tabba wrote:
> When disabling, hyp_trace_clock_enable() cancels the clock work but then
> falls through into the enable path, which re-schedules it and marks the
> clock running again, so the worker never stops. Return once the work is
> cancelled.
> 
> Fixes: b22888917fa41 ("KVM: arm64: Sync boot clock with the nVHE/pKVM hyp")
> Reported-by: Sashiko <sashiko-bot@kernel.org>
> Closes: https://lore.kernel.org/all/20260720172923.E4F161F000E9@smtp.kernel.org/
> Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>

Done here already https://lore.kernel.org/all/alczBmnItMwq8xj4@google.com/

> ---
>  arch/arm64/kvm/hyp_trace.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
> index 2411b4c32932c..27367843fd211 100644
> --- a/arch/arm64/kvm/hyp_trace.c
> +++ b/arch/arm64/kvm/hyp_trace.c
> @@ -116,6 +116,7 @@ static void hyp_trace_clock_enable(struct hyp_trace_clock *hyp_clock, bool enabl
>  	if (!enable) {
>  		cancel_delayed_work_sync(&hyp_clock->work);
>  		hyp_clock->running = false;
> +		return;
>  	}
>  
>  	ktime_get_snapshot_id(CLOCK_BOOTTIME, &snap);
> 
> base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f
> -- 
> 2.39.5
>

Re: [PATCH] KVM: arm64: Stop the hyp trace clock worker on disable

Posted by Vincent Donnefort 4 days, 6 hours ago

On Mon, Jul 20, 2026 at 08:01:55PM +0100, Vincent Donnefort wrote:
> On Mon, Jul 20, 2026 at 07:48:50PM +0100, Fuad Tabba wrote:
> > When disabling, hyp_trace_clock_enable() cancels the clock work but then
> > falls through into the enable path, which re-schedules it and marks the
> > clock running again, so the worker never stops. Return once the work is
> > cancelled.
> > 
> > Fixes: b22888917fa41 ("KVM: arm64: Sync boot clock with the nVHE/pKVM hyp")
> > Reported-by: Sashiko <sashiko-bot@kernel.org>
> > Closes: https://lore.kernel.org/all/20260720172923.E4F161F000E9@smtp.kernel.org/
> > Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
> 
> Done here already https://lore.kernel.org/all/alczBmnItMwq8xj4@google.com/

sorry I meant here:

https://lore.kernel.org/all/20260715105100.3178255-1-vdonnefort@google.com/


> 
> > ---
> >  arch/arm64/kvm/hyp_trace.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
> > index 2411b4c32932c..27367843fd211 100644
> > --- a/arch/arm64/kvm/hyp_trace.c
> > +++ b/arch/arm64/kvm/hyp_trace.c
> > @@ -116,6 +116,7 @@ static void hyp_trace_clock_enable(struct hyp_trace_clock *hyp_clock, bool enabl
> >  	if (!enable) {
> >  		cancel_delayed_work_sync(&hyp_clock->work);
> >  		hyp_clock->running = false;
> > +		return;
> >  	}
> >  
> >  	ktime_get_snapshot_id(CLOCK_BOOTTIME, &snap);
> > 
> > base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f
> > -- 
> > 2.39.5
> >

Re: [PATCH] KVM: arm64: Stop the hyp trace clock worker on disable

Posted by Fuad Tabba 4 days, 6 hours ago

On Mon, 20 Jul 2026 at 20:03, Vincent Donnefort <vdonnefort@google.com> wrote:
>
> On Mon, Jul 20, 2026 at 08:01:55PM +0100, Vincent Donnefort wrote:
> > On Mon, Jul 20, 2026 at 07:48:50PM +0100, Fuad Tabba wrote:
> > > When disabling, hyp_trace_clock_enable() cancels the clock work but then
> > > falls through into the enable path, which re-schedules it and marks the
> > > clock running again, so the worker never stops. Return once the work is
> > > cancelled.
> > >
> > > Fixes: b22888917fa41 ("KVM: arm64: Sync boot clock with the nVHE/pKVM hyp")
> > > Reported-by: Sashiko <sashiko-bot@kernel.org>
> > > Closes: https://lore.kernel.org/all/20260720172923.E4F161F000E9@smtp.kernel.org/
> > > Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
> >
> > Done here already https://lore.kernel.org/all/alczBmnItMwq8xj4@google.com/
>
> sorry I meant here:
>
> https://lore.kernel.org/all/20260715105100.3178255-1-vdonnefort@google.com/

Thanks, and sorry for the noise!
/fuad

>
>
> >
> > > ---
> > >  arch/arm64/kvm/hyp_trace.c | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
> > > index 2411b4c32932c..27367843fd211 100644
> > > --- a/arch/arm64/kvm/hyp_trace.c
> > > +++ b/arch/arm64/kvm/hyp_trace.c
> > > @@ -116,6 +116,7 @@ static void hyp_trace_clock_enable(struct hyp_trace_clock *hyp_clock, bool enabl
> > >     if (!enable) {
> > >             cancel_delayed_work_sync(&hyp_clock->work);
> > >             hyp_clock->running = false;
> > > +           return;
> > >     }
> > >
> > >     ktime_get_snapshot_id(CLOCK_BOOTTIME, &snap);
> > >
> > > base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f
> > > --
> > > 2.39.5
> > >