2016-09-30 13:40+0800, Peter Xu:
> On Thu, Sep 29, 2016 at 01:23:29PM +0200, Radim Krčmář wrote:
>
> [...]
>
>> @@ -2481,11 +2482,14 @@ static void vtd_realize(DeviceState *dev, Error
>> **errp)
>> 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 && pcmc->buggy_intel_iommu_eim) {
>> + s->intr_eim = ON_OFF_AUTO_ON;
>> + }
>> if (s->intr_eim == ON_OFF_AUTO_AUTO) {
>> s->intr_eim = kvm_irqchip_in_kernel() ? ON_OFF_AUTO_ON
>> : ON_OFF_AUTO_OFF;
>> }
>> - if (s->intr_eim == ON_OFF_AUTO_ON) {
>> + if (s->intr_eim == ON_OFF_AUTO_ON && !pcmc->buggy_intel_iommu_eim) {
>> if (kvm_irqchip_in_kernel() && !kvm_enable_x2apic()) {
>> error_report("intel-iommu,eim=on requires support on the KVM
>> side "
>> "(X2APIC_API, first shipped in v4.7).");
>
> No matter how we would treat this patch, I see that we are stacking up
> if clauses here. So IMHO maybe it's time to award EIM a new routine:
>
> int vtd_eim_detect(IntelIOMMUState *, Error **errp);
>
> And squash all these conditions in. Then in vtd_realize():
>
> if (vtd_eim_detect(s, errp)) {
> return;
> }
Yeah, thanks.
