Subject: [RFC PATCH 2/5] arm/arm64: KVM: vgic: kill VGIC_NR_SHARED_IRQS

From: [email-masked] (Christoffer Dall)
Date: Mon, 21 Oct 2013 15:03:15 +0100

On Fri, Oct 04, 2013 at 01:16:15PM +0100, Marc Zyngier wrote:
> having a dynamic number of supported interrupts means that we
> cannot relly on VGIC_NR_SHARED_IRQS anymore, as the upper bound

rely

> is not known anymore.
> 
> Just nuke it.
> 
> Signed-off-by: Marc Zyngier <[email-masked]>
> ---
>  include/kvm/arm_vgic.h |  1 -
>  virt/kvm/arm/vgic.c    | 12 +++++++-----
>  2 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 3cc3a9f..8ce9c08 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -30,7 +30,6 @@
>  #define VGIC_NR_SGIS		16
>  #define VGIC_NR_PPIS		16
>  #define VGIC_NR_PRIVATE_IRQS	(VGIC_NR_SGIS + VGIC_NR_PPIS)
> -#define VGIC_NR_SHARED_IRQS	(VGIC_NR_IRQS - VGIC_NR_PRIVATE_IRQS)
>  #define VGIC_MAX_CPUS		KVM_MAX_VCPUS
>  #define VGIC_MAX_LRS		(1 << 6)
>  
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index f16c848..951b560 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -821,6 +821,7 @@ static int compute_pending_for_cpu(struct kvm_vcpu *vcpu)
>  	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
>  	unsigned long *pending, *enabled, *pend_percpu, *pend_shared;
>  	unsigned long pending_private, pending_shared;
> +	int nr_shared_irqs = dist->nr_irqs - VGIC_NR_PRIVATE_IRQS;
>  	int vcpu_id;
>  
>  	vcpu_id = vcpu->vcpu_id;
> @@ -833,15 +834,15 @@ static int compute_pending_for_cpu(struct kvm_vcpu *vcpu)
>  
>  	pending = vgic_bitmap_get_shared_map(&dist->irq_state);
>  	enabled = vgic_bitmap_get_shared_map(&dist->irq_enabled);
> -	bitmap_and(pend_shared, pending, enabled, VGIC_NR_SHARED_IRQS);
> +	bitmap_and(pend_shared, pending, enabled, nr_shared_irqs);
>  	bitmap_and(pend_shared, pend_shared,
>  		   vgic_bitmap_get_shared_map(&dist->irq_spi_target[vcpu_id]),
> -		   VGIC_NR_SHARED_IRQS);
> +		   nr_shared_irqs);
>  
>  	pending_private = find_first_bit(pend_percpu, VGIC_NR_PRIVATE_IRQS);
> -	pending_shared = find_first_bit(pend_shared, VGIC_NR_SHARED_IRQS);
> +	pending_shared = find_first_bit(pend_shared, nr_shared_irqs);
>  	return (pending_private < VGIC_NR_PRIVATE_IRQS ||
> -		pending_shared < VGIC_NR_SHARED_IRQS);
> +		pending_shared < nr_shared_irqs);
>  }
>  
>  /*
> @@ -1002,6 +1003,7 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
>  {
>  	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>  	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +	int nr_shared_irqs = dist->nr_irqs - VGIC_NR_PRIVATE_IRQS;
>  	int i, vcpu_id;
>  	int overflow = 0;
>  
> @@ -1030,7 +1032,7 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
>  	}
>  
>  	/* SPIs */
> -	for_each_set_bit(i, vgic_cpu->pending_shared, VGIC_NR_SHARED_IRQS) {
> +	for_each_set_bit(i, vgic_cpu->pending_shared, nr_shared_irqs) {
>  		if (!vgic_queue_hwirq(vcpu, i + VGIC_NR_PRIVATE_IRQS))
>  			overflow = 1;
>  	}
> -- 
> 1.8.2.3
> 
> 

nr_shared_irqs could be precomputed on the vgic_dist struct or just be
made a define that takes an argument everywhere - I think the latter
will make some of the code in the previous patch easier to read...

-- 
Christoffer