On 11 December 2011 15:18, Jan Kiszka <jan.kis...@web.de> wrote:
> Just found two, maybe three nits while browsing by:
>
> On 2011-12-11 11:24, Christoffer Dall wrote:
>> +ARM uses two types of interrupt lines per CPU, ie. IRQ and FIQ. The value 
>> of the
>> +irq field should be (VCPU_INDEX * 2) for IRQs and ((VCPU_INDEX * 2) + 1) for
>> +FIQs.

This seems to me a slightly obscure way of defining the two fields
in this word (ie bits [31..1] cpu number, bit [0] irq-vs-fiq).

>> +static int kvm_arch_vm_ioctl_irq_line(struct kvm *kvm,
>> +                                   struct kvm_irq_level *irq_level)
>> +{
>> +     u32 mask;
>> +     unsigned int vcpu_idx;
>> +     struct kvm_vcpu *vcpu;
>> +
>> +     vcpu_idx = irq_level->irq / 2;
>> +     if (vcpu_idx >= KVM_MAX_VCPUS)
>> +             return -EINVAL;
>> +
>> +     vcpu = kvm_get_vcpu(kvm, vcpu_idx);
>> +     if (!vcpu)
>> +             return -EINVAL;
>> +
>> +     switch (irq_level->irq % 2) {
>> +     case KVM_ARM_IRQ_LINE:
>> +             mask = HCR_VI;
>> +             break;
>> +     case KVM_ARM_FIQ_LINE:
>> +             mask = HCR_VF;
>> +             break;
>> +     default:
>> +             return -EINVAL;
>
> Due to % 2, default is unreachable. Remove the masking?

Removing the mask would be wrong since the irq field here
is encoding both cpu number and irq-vs-fiq. The default is
just an unreachable condition. (Why are we using % here
rather than the obvious bit operation, incidentally?)

-- PMM
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