# Re: \[patch 05/24\] KVM: arm64: Use ktime\_get\_snapshot\_id() to retrieve CLOCK\_BOOTTIME

- From: Vincent Donnefort \<vdonnefort@google.com\>
- Date: 2026-05-27 16:29:07 
- List: netdev
- Page: https://ratatoskr.run/netdev/2026/05/17037716
- Thread: https://ratatoskr.run/kvmarm/2026/05/17032577/t.md

```text
On Tue, May 26, 2026 at 07:13:53PM +0200, Thomas Gleixner wrote:
> ktime_get_snapshot() is replaced by ktime_get_snapshot_id() which allows to
> request a particular CLOCK ID to be captured along with the clocksource
> counter.
> 
> Convert the tracing mechanism over and use the new
> system_time_snapshot::sys field, which holds the system timestamp selected
> by the CLOCK ID argument.
> 
> No functional change intended.
> 
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Vincent Donnefort <vdonnefort@google.com>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Oliver Upton <redacted>
> Cc: <redacted>

Acked-by: Vincent Donnefort <vdonnefort@google.com>

> ---
>  arch/arm64/kvm/hyp_trace.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> --- a/arch/arm64/kvm/hyp_trace.c
> +++ b/arch/arm64/kvm/hyp_trace.c
> @@ -51,8 +51,8 @@ static void __hyp_clock_work(struct work
>  
>  	hyp_clock = container_of(dwork, struct hyp_trace_clock, work);
>  
> -	ktime_get_snapshot(&snap);
> -	boot = ktime_to_ns(snap.boot);
> +	ktime_get_snapshot_id(&snap, CLOCK_BOOTTIME);
> +	boot = ktime_to_ns(snap.sys);
>  
>  	delta_boot = boot - hyp_clock->boot;
>  	delta_cycles = snap.cycles - hyp_clock->cycles;
> @@ -118,9 +118,9 @@ static void hyp_trace_clock_enable(struc
>  		hyp_clock->running = false;
>  	}
>  
> -	ktime_get_snapshot(&snap);
> +	ktime_get_snapshot_id(&snap, CLOCK_BOOTTIME);
>  
> -	hyp_clock->boot = ktime_to_ns(snap.boot);
> +	hyp_clock->boot = ktime_to_ns(snap.sys);
>  	hyp_clock->cycles = snap.cycles;
>  	hyp_clock->mult = 0;
>  
> 
```