On 23/12/2015 12:28, Andrey Smetanin wrote:
> This will be used in future to start Hyper-V SynIC timer
> in several places by one logic in one function.
>
> Signed-off-by: Andrey Smetanin <asmeta...@virtuozzo.com>
> Reviewed-by: Roman Kagan <rka...@virtuozzo.com>
> CC: Gleb Natapov <g...@kernel.org>
> CC: Paolo Bonzini <pbonz...@redhat.com>
> CC: Roman Kagan <rka...@virtuozzo.com>
> CC: Denis V. Lunev <d...@openvz.org>
> CC: qemu-devel@nongnu.org
> ---
> arch/x86/kvm/hyperv.c | 37 ++++++++++++++++---------------------
> 1 file changed, 16 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index ec3a900..8623aa6 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -408,6 +408,7 @@ static void stimer_cleanup(struct kvm_vcpu_hv_stimer
> *stimer)
> clear_bit(stimer->index,
> vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
> stimer->msg_pending = false;
> + stimer->exp_time = 0;
> }
>
> static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
> @@ -420,24 +421,6 @@ static enum hrtimer_restart stimer_timer_callback(struct
> hrtimer *timer)
> return HRTIMER_NORESTART;
> }
>
> -static void stimer_restart(struct kvm_vcpu_hv_stimer *stimer)
> -{
> - u64 time_now;
> - ktime_t ktime_now;
> - u64 remainder;
> -
> - time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
> - ktime_now = ktime_get();
> -
> - div64_u64_rem(time_now - stimer->exp_time, stimer->count, &remainder);
> - stimer->exp_time = time_now + (stimer->count - remainder);
> -
> - hrtimer_start(&stimer->timer,
> - ktime_add_ns(ktime_now,
> - 100 * (stimer->exp_time - time_now)),
> - HRTIMER_MODE_ABS);
> -}
> -
> static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
> {
> u64 time_now;
> @@ -450,9 +433,21 @@ static int stimer_start(struct kvm_vcpu_hv_stimer
> *stimer)
> if (stimer->count == 0)
> return -EINVAL;
>
> - stimer->exp_time = time_now + stimer->count;
> + if (stimer->exp_time) {
> + if (time_now >= stimer->exp_time) {
Just for my education, is it possible to have this function called with
stimer->exp_time != 0 && time_now < stimer->exp_time?
Paolo
> + u64 remainder;
> +
> + div64_u64_rem(time_now - stimer->exp_time,
> + stimer->count, &remainder);
> + stimer->exp_time =
> + time_now + (stimer->count - remainder);
> + }
> + } else
> + stimer->exp_time = time_now + stimer->count;
> +
> hrtimer_start(&stimer->timer,
> - ktime_add_ns(ktime_now, 100 * stimer->count),
> + ktime_add_ns(ktime_now,
> + 100 * (stimer->exp_time - time_now)),
> HRTIMER_MODE_ABS);
> return 0;
> }
> @@ -580,7 +575,7 @@ static void stimer_expiration(struct kvm_vcpu_hv_stimer
> *stimer)
> if (!(stimer->config & HV_STIMER_PERIODIC))
> stimer->config |= ~HV_STIMER_ENABLE;
> else
> - stimer_restart(stimer);
> + stimer_start(stimer);
> }
>
> void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
>
