Subject: [PATCH 2/7] KVM: arm/arm64: directly pass virtual IRQ number on injecting mapped IRQ

From: [email-masked] (Andre Przywara)
Date: Mon, 25 Apr 2016 11:13:27 +0100

Hi Eric,

thanks for looking at the patches!

On 21/04/16 18:09, Eric Auger wrote:
> Hi Andre,
> On 04/15/2016 04:04 PM, Andre Przywara wrote:
>> When we want to inject a hardware mapped IRQ into a guest, we actually
>> only need the virtual IRQ number from the irq_phys_map.
>> So let's pass this number directly from the arch timer to the VGIC
>> to avoid using the map as a parameter.
>>
>> Signed-off-by: Andre Przywara <[email-masked]>
>> ---
>>  include/kvm/arm_vgic.h    | 2 +-
>>  virt/kvm/arm/arch_timer.c | 2 +-
>>  virt/kvm/arm/vgic.c       | 6 +++---
>>  3 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index 281caf8..c4574da 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -341,7 +341,7 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
>>  int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
>>  			bool level);
>>  int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid,
>> -			       struct irq_phys_map *map, bool level);
>> +			       unsigned int virt_irq, bool level);
>>  void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
>>  int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
>>  struct irq_phys_map *kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu,
>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
>> index a9ad4fe..eb56f1e 100644
>> --- a/virt/kvm/arm/arch_timer.c
>> +++ b/virt/kvm/arm/arch_timer.c
>> @@ -140,7 +140,7 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level)
>>  	trace_kvm_timer_update_irq(vcpu->vcpu_id, timer->map->virt_irq,
>>  				   timer->irq.level);
>>  	ret = kvm_vgic_inject_mapped_irq(vcpu->kvm, vcpu->vcpu_id,
>> -					 timer->map,
>> +					 timer->map->virt_irq,
>>  					 timer->irq.level);
>>  	WARN_ON(ret);
>>  }
>> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
>> index 7282881..9937d41 100644
>> --- a/virt/kvm/arm/vgic.c
>> +++ b/virt/kvm/arm/vgic.c
>> @@ -1667,7 +1667,7 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
>>   * kvm_vgic_inject_mapped_irq - Inject a physically mapped IRQ to the vgic
>>   * @kvm:     The VM structure pointer
>>   * @cpuid:   The CPU for PPIs
>> - * @map:     Pointer to a irq_phys_map structure describing the mapping
>> + * @virt_irq: The virtual IRQ to be injected
>>   * @level:   Edge-triggered:  true:  to trigger the interrupt
>>   *			      false: to ignore the call
>>   *	     Level-sensitive  true:  raise the input signal
>> @@ -1678,7 +1678,7 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
>>   * being HIGH and 0 being LOW and all devices being active-HIGH.
>>   */
>>  int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid,
>> -			       struct irq_phys_map *map, bool level)
>> +			       unsigned int virt_irq, bool level)
>>  {
> Could make sense to merge kvm_vgic_inject_mapped_irq and
> kvm_vgic_inject_irq and just add a bool argument telling whether the
> request comes from the userspace (if I remember well we wanted to
> prevent the userspace from injecting a mapping irq). This would avoid
> duplication. We can make it later though.

Yes, actually I merge both of them in the new VGIC series (44/45: [1]).
But this mini-series aims to stay as close as possible to the original
code, so I think we will properly unify this once the old VGIC gets removed.

But thanks for the heads up with the userspace injection and mapped
IRQs, I was wondering the other day what the differences between the two
actually were. This may mean I have to rework the 44/45 patch.

> Reviewed-by: Eric Auger <[email-masked]>

Merci!

Cheers,
Andre.

[1] https://lists.cs.columbia.edu/pipermail/kvmarm/2016-April/019671.html

>>  	int ret;
>>  
>> @@ -1686,7 +1686,7 @@ int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid,
>>  	if (ret)
>>  		return ret;
>>  
>> -	return vgic_update_irq_pending(kvm, cpuid, map->virt_irq, level);
>> +	return vgic_update_irq_pending(kvm, cpuid, virt_irq, level);
>>  }
>>  
>>  static irqreturn_t vgic_maintenance_handler(int irq, void *data)
>>
>