Re: [PATCH 2/2] KVM: s390: do not set intervention requests for GISA interrupts

[David Hildenbrand <david@redhat.com>]

On 13.02.2018 13:28, Christian Borntraeger wrote:
> If GISA is available, we do not have to kick CPUs out of SIE to deliver
> interrupts. The hardware can deliver such interrupts while running.
> 
> Cc: Michael Mueller <mimu@linux.vnet.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  arch/s390/kvm/interrupt.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> index 337a69bc04db..e399495001ca 100644
> --- a/arch/s390/kvm/interrupt.c
> +++ b/arch/s390/kvm/interrupt.c
> @@ -236,10 +236,15 @@ static inline int kvm_s390_gisa_tac_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gis
>  	return test_and_clear_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa);
>  }
>  
> -static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu)
> +static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu)
>  {
>  	return vcpu->kvm->arch.float_int.pending_irqs |
> -		vcpu->arch.local_int.pending_irqs |
> +		vcpu->arch.local_int.pending_irqs;
> +}
> +
> +static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu)
> +{
> +	return pending_irqs_no_gisa(vcpu) |
>  		kvm_s390_gisa_get_ipm(vcpu->kvm->arch.gisa) << IRQ_PEND_IO_ISC_7;
>  }
>  
> @@ -337,7 +342,7 @@ static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)
>  
>  static void set_intercept_indicators_io(struct kvm_vcpu *vcpu)
>  {
> -	if (!(pending_irqs(vcpu) & IRQ_PEND_IO_MASK))
> +	if (!(pending_irqs_no_gisa(vcpu) & IRQ_PEND_IO_MASK))
>  		return;
>  	else if (psw_ioint_disabled(vcpu))
>  		kvm_s390_set_cpuflags(vcpu, CPUSTAT_IO_INT);
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David / dhildenb