Re: [PATCH v8 4/7] KVM: Add reset/restore rtc_status support

[Gleb Natapov <gleb@redhat.com>]

On Mon, Apr 08, 2013 at 10:17:46PM +0800, Yang Zhang wrote:
> From: Yang Zhang <yang.z.zhang@Intel.com>
> 
> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
> ---
>  arch/x86/kvm/lapic.c |    9 +++++++
>  arch/x86/kvm/lapic.h |    2 +
>  virt/kvm/ioapic.c    |   60 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  virt/kvm/ioapic.h    |    1 +
>  4 files changed, 72 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 0b73402..6796218 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -94,6 +94,14 @@ static inline int apic_test_vector(int vec, void *bitmap)
>  	return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
>  }
>  
> +bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector)
> +{
> +	struct kvm_lapic *apic = vcpu->arch.apic;
> +
> +	return apic_test_vector(vector, apic->regs + APIC_ISR) ||
> +		apic_test_vector(vector, apic->regs + APIC_IRR);
> +}
> +
>  static inline void apic_set_vector(int vec, void *bitmap)
>  {
>  	set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
> @@ -1618,6 +1626,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
>  	apic->highest_isr_cache = -1;
>  	kvm_x86_ops->hwapic_isr_update(vcpu->kvm, apic_find_highest_isr(apic));
>  	kvm_make_request(KVM_REQ_EVENT, vcpu);
> +	kvm_rtc_eoi_tracking_restore_one(vcpu);
>  }
>  
>  void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> index 3e5a431..16304b1 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -166,4 +166,6 @@ static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu)
>  	return vcpu->arch.apic->pending_events;
>  }
>  
> +bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector);
> +
>  #endif
> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
> index 27ae8dd..4699180 100644
> --- a/virt/kvm/ioapic.c
> +++ b/virt/kvm/ioapic.c
> @@ -90,6 +90,64 @@ static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
>  	return result;
>  }
>  
> +static void rtc_irq_reset(struct kvm_ioapic *ioapic)
rtc_irq_eoi_tracking_reset()

> +{
> +	ioapic->rtc_status.pending_eoi = 0;
> +	bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
> +}
> +
> +static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu,
> +						int vector)
> +{
> +	bool new_val, old_val;
> +	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
> +	union kvm_ioapic_redirect_entry *e;
> +
> +	e = &ioapic->redirtbl[RTC_GSI];
> +	if (!kvm_apic_match_dest(vcpu, NULL, 0,	e->fields.dest_id,
> +				e->fields.dest_mode))
> +		return;
> +
> +	new_val = kvm_apic_pending_eoi(vcpu, vector);
> +	old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
> +
> +	if (new_val == old_val)
> +		return;
> +
> +	if (new_val) {
> +		__set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
> +		ioapic->rtc_status.pending_eoi++;
> +	} else {
> +		__clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
> +		ioapic->rtc_status.pending_eoi--;
> +	}
WARN_ON(ioapic->rtc_status.pending_eoi < 0);

> +}
> +
> +void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
> +{
> +	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
> +	int vector;
> +
> +	vector = ioapic->redirtbl[RTC_GSI].fields.vector;
Do not access ioapic outside of the lock. Also since you access
ioapic->redirtbl[RTC_GSI] in __rtc_irq_eoi_tracking_restore_one()
anyway what's the point passing vector to it?

> +	spin_lock(&ioapic->lock);
> +	__rtc_irq_eoi_tracking_restore_one(vcpu, vector);
> +	spin_unlock(&ioapic->lock);
> +}
> +
> +static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
> +{
> +	struct kvm_vcpu *vcpu;
> +	int i, vector;
> +
> +	if (RTC_GSI >= IOAPIC_NUM_PINS)
> +		return;
> +
> +	rtc_irq_reset(ioapic);
> +	vector = ioapic->redirtbl[RTC_GSI].fields.vector;
> +	kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
> +	    __rtc_irq_eoi_tracking_restore_one(vcpu, vector);
> +}
> +
>  static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
>  {
>  	union kvm_ioapic_redirect_entry *pent;
> @@ -428,6 +486,7 @@ void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
>  	ioapic->ioregsel = 0;
>  	ioapic->irr = 0;
>  	ioapic->id = 0;
> +	rtc_irq_reset(ioapic);
>  	update_handled_vectors(ioapic);
>  }
>  
> @@ -494,6 +553,7 @@ int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
>  	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
>  	update_handled_vectors(ioapic);
>  	kvm_ioapic_make_eoibitmap_request(kvm);
> +	kvm_rtc_eoi_tracking_restore_all(ioapic);
>  	spin_unlock(&ioapic->lock);
>  	return 0;
>  }
> diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
> index 761e5b5..313fc4e 100644
> --- a/virt/kvm/ioapic.h
> +++ b/virt/kvm/ioapic.h
> @@ -79,6 +79,7 @@ static inline struct kvm_ioapic *ioapic_irqchip(struct kvm *kvm)
>  	return kvm->arch.vioapic;
>  }
>  
> +void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu);
>  int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
>  		int short_hand, int dest, int dest_mode);
>  int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2);
> -- 
> 1.7.1

--
			Gleb.