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Commit f3b138c5 authored by Andrey Smetanin's avatar Andrey Smetanin Committed by Paolo Bonzini
Browse files

kvm/x86: Update SynIC timers on guest entry only 



Consolidate updating the Hyper-V SynIC timers in a
single place: on guest entry in processing KVM_REQ_HV_STIMER
request.  This simplifies the overall logic, and makes sure
the most current state of msrs and guest clock is used for
arming the timers (to achieve that, KVM_REQ_HV_STIMER
has to be processed after KVM_REQ_CLOCK_UPDATE).

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 7be58a64

arch/x86/kvm/hyperv.c

+19 −19
Original line number Diff line number Diff line
@@ -389,7 +389,7 @@ static u64 get_time_ref_counter(struct kvm *kvm) 
	return div_u64(get_kernel_ns() + kvm->arch.kvmclock_offset, 100);

}



static void stimer_mark_expired(struct kvm_vcpu_hv_stimer *stimer,

static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,

				bool vcpu_kick)

{

	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
@@ -417,7 +417,7 @@ static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer) 
	struct kvm_vcpu_hv_stimer *stimer;



	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);

	stimer_mark_expired(stimer, true);

	stimer_mark_pending(stimer, true);



	return HRTIMER_NORESTART;

}
@@ -462,7 +462,7 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) 
		 * "If a one shot is enabled and the specified count is in

		 * the past, it will expire immediately."

		 */

		stimer_mark_expired(stimer, false);

		stimer_mark_pending(stimer, false);

		return 0;

	}
@@ -475,30 +475,24 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) 
static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,

			     bool host)

{

	stimer_cleanup(stimer);

	if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0)

		config &= ~HV_STIMER_ENABLE;

	stimer->config = config;

	stimer_cleanup(stimer);

	if (stimer->config & HV_STIMER_ENABLE)

		if (stimer_start(stimer))

			return 1;

	stimer_mark_pending(stimer, false);

	return 0;

}



static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,

			    bool host)

{

	stimer->count = count;



	stimer_cleanup(stimer);

	stimer->count = count;

	if (stimer->count == 0)

		stimer->config &= ~HV_STIMER_ENABLE;

	else if (stimer->config & HV_STIMER_AUTOENABLE) {

	else if (stimer->config & HV_STIMER_AUTOENABLE)

		stimer->config |= HV_STIMER_ENABLE;

		if (stimer_start(stimer))

			return 1;

	}



	stimer_mark_pending(stimer, false);

	return 0;

}
@@ -582,18 +576,24 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu) 
{

	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);

	struct kvm_vcpu_hv_stimer *stimer;

	u64 time_now;

	u64 time_now, exp_time;

	int i;



	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)

		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {

			stimer = &hv_vcpu->stimer[i];

			if (stimer->config & HV_STIMER_ENABLE) {

				time_now = get_time_ref_counter(vcpu->kvm);

				if (time_now >= stimer->exp_time)

				exp_time = stimer->exp_time;



				if (exp_time) {

					time_now =

						get_time_ref_counter(vcpu->kvm);

					if (time_now >= exp_time)

						stimer_expiration(stimer);

				}



				if (stimer->config & HV_STIMER_ENABLE)

				if ((stimer->config & HV_STIMER_ENABLE) &&

				    stimer->count)

					stimer_start(stimer);

				else

					stimer_cleanup(stimer);

arch/x86/kvm/x86.c

+6 −0
Original line number Diff line number Diff line
@@ -6508,6 +6508,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) 
			r = 0;

			goto out;

		}



		/*

		 * KVM_REQ_HV_STIMER has to be processed after

		 * KVM_REQ_CLOCK_UPDATE, because Hyper-V SynIC timers

		 * depend on the guest clock being up-to-date

		 */

		if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu))

			kvm_hv_process_stimers(vcpu);

	}