[PATCH 1/2] KVM: x86: Simplify __apic_accept_irq

[PATCH 1/2] KVM: x86: Simplify __apic_accept_irq

[Jan Kiszka]

If posted interrupts are enabled, we can no longer track if an IRQ was
coalesced based on IRR. So drop this logic also from the classic
software path and simplify apic_test_and_set_irr to apic_set_irr.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kvm/lapic.c |   23 ++++++++---------------
 1 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index afc1124..9dc3650 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -331,10 +331,10 @@ void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir)
 }
 EXPORT_SYMBOL_GPL(kvm_apic_update_irr);
 
-static inline int apic_test_and_set_irr(int vec, struct kvm_lapic *apic)
+static inline void apic_set_irr(int vec, struct kvm_lapic *apic)
 {
 	apic->irr_pending = true;
-	return apic_test_and_set_vector(vec, apic->regs + APIC_IRR);
+	apic_set_vector(vec, apic->regs + APIC_IRR);
 }
 
 static inline int apic_search_irr(struct kvm_lapic *apic)
@@ -681,28 +681,21 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 		if (unlikely(!apic_enabled(apic)))
 			break;
 
+		result = 1;
+
 		if (dest_map)
 			__set_bit(vcpu->vcpu_id, dest_map);
 
-		if (kvm_x86_ops->deliver_posted_interrupt) {
-			result = 1;
+		if (kvm_x86_ops->deliver_posted_interrupt)
 			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
-		} else {
-			result = !apic_test_and_set_irr(vector, apic);
-
-			if (!result) {
-				if (trig_mode)
-					apic_debug("level trig mode repeatedly "
-						"for vector %d", vector);
-				goto out;
-			}
+		else {
+			apic_set_irr(vector, apic);
 
 			kvm_make_request(KVM_REQ_EVENT, vcpu);
 			kvm_vcpu_kick(vcpu);
 		}
-out:
 		trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
-				trig_mode, vector, !result);
+					  trig_mode, vector, false);
 		break;
 
 	case APIC_DM_REMRD:
-- 
1.7.3.4

[PATCH 2/2] KVM: x86: Drop some unused functions from lapic

[Jan Kiszka]

Both have no users anymore.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kvm/lapic.c |   10 ----------
 1 files changed, 0 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 9dc3650..c98f054 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -79,16 +79,6 @@ static inline void apic_set_reg(struct kvm_lapic *apic, int reg_off, u32 val)
 	*((u32 *) (apic->regs + reg_off)) = val;
 }
 
-static inline int apic_test_and_set_vector(int vec, void *bitmap)
-{
-	return test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
-}
-
-static inline int apic_test_and_clear_vector(int vec, void *bitmap)
-{
-	return test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
-}
-
 static inline int apic_test_vector(int vec, void *bitmap)
 {
 	return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
-- 
1.7.3.4

Re: [PATCH 1/2] KVM: x86: Simplify __apic_accept_irq

[Gleb Natapov]

On Thu, Jul 25, 2013 at 09:58:45AM +0200, Jan Kiszka wrote:
> If posted interrupts are enabled, we can no longer track if an IRQ was
> coalesced based on IRR. So drop this logic also from the classic
> software path and simplify apic_test_and_set_irr to apic_set_irr.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Applied both, thanks.

> ---
>  arch/x86/kvm/lapic.c |   23 ++++++++---------------
>  1 files changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index afc1124..9dc3650 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -331,10 +331,10 @@ void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir)
>  }
>  EXPORT_SYMBOL_GPL(kvm_apic_update_irr);
>  
> -static inline int apic_test_and_set_irr(int vec, struct kvm_lapic *apic)
> +static inline void apic_set_irr(int vec, struct kvm_lapic *apic)
>  {
>  	apic->irr_pending = true;
> -	return apic_test_and_set_vector(vec, apic->regs + APIC_IRR);
> +	apic_set_vector(vec, apic->regs + APIC_IRR);
>  }
>  
>  static inline int apic_search_irr(struct kvm_lapic *apic)
> @@ -681,28 +681,21 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
>  		if (unlikely(!apic_enabled(apic)))
>  			break;
>  
> +		result = 1;
> +
>  		if (dest_map)
>  			__set_bit(vcpu->vcpu_id, dest_map);
>  
> -		if (kvm_x86_ops->deliver_posted_interrupt) {
> -			result = 1;
> +		if (kvm_x86_ops->deliver_posted_interrupt)
>  			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
> -		} else {
> -			result = !apic_test_and_set_irr(vector, apic);
> -
> -			if (!result) {
> -				if (trig_mode)
> -					apic_debug("level trig mode repeatedly "
> -						"for vector %d", vector);
> -				goto out;
> -			}
> +		else {
> +			apic_set_irr(vector, apic);
>  
>  			kvm_make_request(KVM_REQ_EVENT, vcpu);
>  			kvm_vcpu_kick(vcpu);
>  		}
> -out:
>  		trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
> -				trig_mode, vector, !result);
> +					  trig_mode, vector, false);
>  		break;
>  
>  	case APIC_DM_REMRD:
> -- 
> 1.7.3.4

--
			Gleb.