[PATCH v6 11/21] KVM: arm64: Refactor update_vtimer_cntvoff()

[Andrew Jones]

On Wed, Aug 04, 2021 at 08:58:09AM +0000, Oliver Upton wrote:
> Make the implementation of update_vtimer_cntvoff() generic w.r.t. guest
> timer context and spin off into a new helper method for later use.
> Require callers of this new helper method to grab the kvm lock
> beforehand.
> 
> No functional change intended.
> 
> Signed-off-by: Oliver Upton <oupton at google.com>
> ---
>  arch/arm64/kvm/arch_timer.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
> index 3df67c127489..c0101db75ad4 100644
> --- a/arch/arm64/kvm/arch_timer.c
> +++ b/arch/arm64/kvm/arch_timer.c
> @@ -747,22 +747,32 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
>  	return 0;
>  }
>  
> -/* Make the updates of cntvoff for all vtimer contexts atomic */
> -static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff)
> +/* Make offset updates for all timer contexts atomic */
> +static void update_timer_offset(struct kvm_vcpu *vcpu,
> +				enum kvm_arch_timers timer, u64 offset)
>  {
>  	int i;
>  	struct kvm *kvm = vcpu->kvm;
>  	struct kvm_vcpu *tmp;
>  
> -	mutex_lock(&kvm->lock);
> +	lockdep_assert_held(&kvm->lock);
> +
>  	kvm_for_each_vcpu(i, tmp, kvm)
> -		timer_set_offset(vcpu_vtimer(tmp), cntvoff);
> +		timer_set_offset(vcpu_get_timer(tmp, timer), offset);
>  
>  	/*
>  	 * When called from the vcpu create path, the CPU being created is not
>  	 * included in the loop above, so we just set it here as well.
>  	 */
> -	timer_set_offset(vcpu_vtimer(vcpu), cntvoff);
> +	timer_set_offset(vcpu_get_timer(vcpu, timer), offset);
> +}
> +
> +static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff)
> +{
> +	struct kvm *kvm = vcpu->kvm;
> +
> +	mutex_lock(&kvm->lock);
> +	update_timer_offset(vcpu, TIMER_VTIMER, cntvoff);
>  	mutex_unlock(&kvm->lock);
>  }
>  
> -- 
> 2.32.0.605.g8dce9f2422-goog
>

Reviewed-by: Andrew Jones <drjones at redhat.com>