diff mbox

[2/6] KVM: x86: decouple irqchip_in_kernel() and pic_irqchip()

Message ID 20161124163134.4630-3-rkrcmar@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Radim Krčmář Nov. 24, 2016, 4:31 p.m. UTC
irqchip_in_kernel() tried to save a bit by reusing pic_irqchip(), but it
just complicated the code.
Add kvm->arch.irqchip_kvm that matches kvm->arch.irqchip_split.
(Turning them into an exclusive type would be nicer.)

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/irq.h              | 13 +++++++------
 arch/x86/kvm/x86.c              |  3 ++-
 3 files changed, 10 insertions(+), 7 deletions(-)

Comments

Paolo Bonzini Nov. 24, 2016, 4:55 p.m. UTC | #1
> irqchip_in_kernel() tried to save a bit by reusing pic_irqchip(), but it
> just complicated the code.
> Add kvm->arch.irqchip_kvm that matches kvm->arch.irqchip_split.
> (Turning them into an exclusive type would be nicer.)

Then do it. ;)

Paolo

> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
> ---
>  arch/x86/include/asm/kvm_host.h |  1 +
>  arch/x86/kvm/irq.h              | 13 +++++++------
>  arch/x86/kvm/x86.c              |  3 ++-
>  3 files changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h
> b/arch/x86/include/asm/kvm_host.h
> index bdde80731f49..929228ec2839 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -778,6 +778,7 @@ struct kvm_arch {
>  
>  	u64 disabled_quirks;
>  
> +	bool irqchip_kvm;
>  	bool irqchip_split;
>  	u8 nr_reserved_ioapic_pins;
>  
> diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
> index 035731eb3897..8536be85d529 100644
> --- a/arch/x86/kvm/irq.h
> +++ b/arch/x86/kvm/irq.h
> @@ -96,15 +96,16 @@ static inline int irqchip_split(struct kvm *kvm)
>  	return kvm->arch.irqchip_split;
>  }
>  
> +static inline int irqchip_kvm(struct kvm *kvm)
> +{
> +	return kvm->arch.irqchip_kvm;
> +}
> +
>  static inline int irqchip_in_kernel(struct kvm *kvm)
>  {
> -	struct kvm_pic *vpic = pic_irqchip(kvm);
> -	bool ret;
> +	bool ret = irqchip_kvm(kvm) || irqchip_split(kvm);
>  
> -	ret = (vpic != NULL);
> -	ret |= irqchip_split(kvm);
> -
> -	/* Read vpic before kvm->irq_routing.  */
> +	/* Matches with wmb after initializing kvm->irq_routing. */
>  	smp_rmb();
>  	return ret;
>  }
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index dbed51045c37..dd8431a7e18b 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3928,8 +3928,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
>  			mutex_unlock(&kvm->slots_lock);
>  			goto create_irqchip_unlock;
>  		}
> -		/* Write kvm->irq_routing before kvm->arch.vpic.  */
> +		/* Write kvm->irq_routing before enabling irqchip_in_kernel. */
>  		smp_wmb();
> +		kvm->arch.irqchip_kvm = true;
>  		kvm->arch.vpic = vpic;
>  	create_irqchip_unlock:
>  		mutex_unlock(&kvm->lock);
> --
> 2.10.2
> 
> 
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index bdde80731f49..929228ec2839 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -778,6 +778,7 @@  struct kvm_arch {
 
 	u64 disabled_quirks;
 
+	bool irqchip_kvm;
 	bool irqchip_split;
 	u8 nr_reserved_ioapic_pins;
 
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 035731eb3897..8536be85d529 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -96,15 +96,16 @@  static inline int irqchip_split(struct kvm *kvm)
 	return kvm->arch.irqchip_split;
 }
 
+static inline int irqchip_kvm(struct kvm *kvm)
+{
+	return kvm->arch.irqchip_kvm;
+}
+
 static inline int irqchip_in_kernel(struct kvm *kvm)
 {
-	struct kvm_pic *vpic = pic_irqchip(kvm);
-	bool ret;
+	bool ret = irqchip_kvm(kvm) || irqchip_split(kvm);
 
-	ret = (vpic != NULL);
-	ret |= irqchip_split(kvm);
-
-	/* Read vpic before kvm->irq_routing.  */
+	/* Matches with wmb after initializing kvm->irq_routing. */
 	smp_rmb();
 	return ret;
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dbed51045c37..dd8431a7e18b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3928,8 +3928,9 @@  long kvm_arch_vm_ioctl(struct file *filp,
 			mutex_unlock(&kvm->slots_lock);
 			goto create_irqchip_unlock;
 		}
-		/* Write kvm->irq_routing before kvm->arch.vpic.  */
+		/* Write kvm->irq_routing before enabling irqchip_in_kernel. */
 		smp_wmb();
+		kvm->arch.irqchip_kvm = true;
 		kvm->arch.vpic = vpic;
 	create_irqchip_unlock:
 		mutex_unlock(&kvm->lock);