Re: [PATCH v2 12/12] KVM: s390: introduce the format-1 GISA

[David Hildenbrand <david@redhat.com>]

On 25.01.2018 16:43, Christian Borntraeger wrote:
> 
> 
> On 01/25/2018 04:31 PM, David Hildenbrand wrote:
> [...]
>>>  struct kvm_s390_vsie {
>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>>> index 68d7eef..efde264 100644
>>> --- a/arch/s390/kvm/kvm-s390.c
>>> +++ b/arch/s390/kvm/kvm-s390.c
>>> @@ -2518,6 +2518,8 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
>>>  	vcpu->arch.sie_block->icpua = id;
>>>  	spin_lock_init(&vcpu->arch.local_int.lock);
>>>  	vcpu->arch.sie_block->gd = (u32)(u64)kvm->arch.gisa;
>>> +	if (vcpu->arch.sie_block->gd && sclp.has_gisaf)
>>> +		vcpu->arch.sie_block->gd |= GISA_FORMAT1;

wonder if the would be nicer via

if (kvm->arch.gisa) {
	vcpu->arch.sie_block->gd = (u32)(u64)kvm->arch.gisa;
	if (sclp.has_gisaf)
		cpu->arch.sie_block->gd |= GISA_FORMAT1;
}

>>>  	seqcount_init(&vcpu->arch.cputm_seqcount);
>>>  
>>>  	rc = kvm_vcpu_init(vcpu, kvm, id);
>>>
>>
>> So, what does this bring us? We don't seem to be using any new GISA-1
>> features.
> 
> Preparation for device pass-through interrupt forwarding.
> 

Can you add something like that to the patch description?

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

-- 

Thanks,

David / dhildenb