/**
* kvm_timer_sync_hwstate - sync timer state from cpu
* @vcpu: The vcpu pointer
*
* Check if the virtual timer was armed and either schedule a corresponding
* soft timer or inject directly if already expired.
*/
void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
cycle_t cval, now;
u64 ns;
if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
!(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
return;
cval = timer->cntv_cval;
now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
BUG_ON(timer_is_armed(timer));
if (cval <= now) {
/*
* Timer has already expired while we were not
* looking. Inject the interrupt and carry on.
*/
kvm_timer_inject_irq(vcpu);
return;
}
ns = cyclecounter_cyc2ns(timecounter->cc, cval - now);
timer_arm(timer, ns);
}
/*
* Schedule the background timer before calling kvm_vcpu_block, so that this
* thread is removed from its waitqueue and made runnable when there's a timer
* interrupt to handle.
*/
void kvm_timer_schedule(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
u64 ns;
cycle_t cval, now;
BUG_ON(timer_is_armed(timer));
/*
* No need to schedule a background timer if the guest timer has
* already expired, because kvm_vcpu_block will return before putting
* the thread to sleep.
*/
if (kvm_timer_should_fire(vcpu))
return;
/*
* If the timer is not capable of raising interrupts (disabled or
* masked), then there's no more work for us to do.
*/
if (!kvm_timer_irq_can_fire(vcpu))
return;
/* The timer has not yet expired, schedule a background timer */
cval = timer->cntv_cval;
now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
ns = cyclecounter_cyc2ns(timecounter->cc,
cval - now,
timecounter->mask,
&timecounter->frac);
timer_arm(timer, ns);
}
int kvm_timer_init(struct kvm *kvm)
{
if (timecounter && wqueue) {
kvm->arch.timer.cntvoff = kvm_phys_timer_read();
kvm->arch.timer.enabled = 1;
}
return 0;
}
bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
cycle_t cval, now;
if (!kvm_timer_irq_can_fire(vcpu))
return false;
cval = timer->cntv_cval;
now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
return cval <= now;
}
u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
switch (regid) {
case KVM_REG_ARM_TIMER_CTL:
return timer->cntv_ctl;
case KVM_REG_ARM_TIMER_CNT:
return kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
case KVM_REG_ARM_TIMER_CVAL:
return timer->cntv_cval;
}
return (u64)-1;
}
int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
switch (regid) {
case KVM_REG_ARM_TIMER_CTL:
timer->cntv_ctl = value;
break;
case KVM_REG_ARM_TIMER_CNT:
vcpu->kvm->arch.timer.cntvoff = kvm_phys_timer_read() - value;
break;
case KVM_REG_ARM_TIMER_CVAL:
timer->cntv_cval = value;
break;
default:
return -1;
}
kvm_timer_update_state(vcpu);
return 0;
}
void kvm_timer_init(struct kvm *kvm)
{
kvm->arch.timer.cntvoff = kvm_phys_timer_read();
}
