aboutsummaryrefslogblamecommitdiffstats
path: root/arch/x86/kvm/timer.c
blob: 4ddadb1a5ffe5f97f51eaa93b6c6fc9c9fe6c4c4 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11










                                                                          


                                                                             

                                                                         

                                                                 
                                             
                                                                           
                                                                
         

















                                                                               
                            









                                                     
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/hrtimer.h>
#include <asm/atomic.h>
#include "kvm_timer.h"

static int __kvm_timer_fn(struct kvm_vcpu *vcpu, struct kvm_timer *ktimer)
{
	int restart_timer = 0;
	wait_queue_head_t *q = &vcpu->wq;

	/*
	 * There is a race window between reading and incrementing, but we do
	 * not care about potentially loosing timer events in the !reinject
	 * case anyway. Note: KVM_REQ_PENDING_TIMER is implicitly checked
	 * in vcpu_enter_guest.
	 */
	if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
		atomic_inc(&ktimer->pending);
		/* FIXME: this code should not know anything about vcpus */
		set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
	}

	if (waitqueue_active(q))
		wake_up_interruptible(q);

	if (ktimer->t_ops->is_periodic(ktimer)) {
		hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
		restart_timer = 1;
	}

	return restart_timer;
}

enum hrtimer_restart kvm_timer_fn(struct hrtimer *data)
{
	int restart_timer;
	struct kvm_vcpu *vcpu;
	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);

	vcpu = ktimer->vcpu;
	if (!vcpu)
		return HRTIMER_NORESTART;

	restart_timer = __kvm_timer_fn(vcpu, ktimer);
	if (restart_timer)
		return HRTIMER_RESTART;
	else
		return HRTIMER_NORESTART;
}