Commit f808495d authored by Andrey Smetanin's avatar Andrey Smetanin Committed by Paolo Bonzini
Browse files

kvm/x86: Hyper-V unify stimer_start() and stimer_restart() 



This will be used in future to start Hyper-V SynIC timer
in several places by one logic in one function.

Changes v2:
* drop stimer->count == 0 check inside stimer_start()
* comment stimer_start() assumptions

Signed-off-by: default avatarAndrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 019b9781

arch/x86/kvm/hyperv.c

+20 −23
Original line number Diff line number Diff line
@@ -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 +421,11 @@ 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);

}



/*

 * stimer_start() assumptions:

 * a) stimer->count is not equal to 0

 * b) stimer->config has HV_STIMER_ENABLE flag

 */

static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)

{

	u64 time_now;
@@ -447,12 +435,21 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) 
	ktime_now = ktime_get();



	if (stimer->config & HV_STIMER_PERIODIC) {

		if (stimer->count == 0)

			return -EINVAL;

		if (stimer->exp_time) {

			if (time_now >= stimer->exp_time) {

				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 +577,7 @@ 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)

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