Re: [Qemu-devel] [PATCH v2 5/7] intel-iommu: add OnOffAuto intr_eim as "eim" property

["Radim Krčmář" <rkrcmar@redhat.com>]

2016-09-30 13:13+0800, Peter Xu:
> On Thu, Sep 29, 2016 at 01:23:27PM +0200, Radim Krčmář wrote:
>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>> @@ -2466,6 +2472,18 @@ static void vtd_realize(DeviceState *dev, Error **errp)
>>          exit(1);
>>      }
>>  
>> +    if (s->intr_eim == ON_OFF_AUTO_ON && !x86_iommu->intr_supported) {
>> +        error_report("intel-iommu,eim=on cannot be selected without "
>> +                     "intremap=on.");
>> +        exit(1);
>> +    }
>> +    if (s->intr_eim == ON_OFF_AUTO_AUTO && !x86_iommu->intr_supported) {
>> +        s->intr_eim = ON_OFF_AUTO_OFF;
>> +    }
>> +    if (s->intr_eim == ON_OFF_AUTO_AUTO) {
>> +        s->intr_eim = ON_OFF_AUTO_ON;
>> +    }
> 
> A single if() instead of above two might be nicer:
> 
>     if (s->intr_eim == ON_OFF_AUTO_AUTO) {
>         e->intr_eim = x86_iommu->intr_supported ?
>             ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
>     }

Hm, it'll end up looking like

    if (s->intr_eim == ON_OFF_AUTO_AUTO) {
        e->intr_eim = (x86_iommu->intr_supported && kvm_irqchip_in_kernel()) ||
                      pcmc->buggy_intel_iommu_eim ?
                                              ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
    }

It's harder to read, but less LOC ... I'll use it, thanks.