Re: [Qemu-devel] [PATCH RFC V5 6/9] hw/intc: arm_gicv3_spi_its

[Pavel Fedin]

 Hello!

> I just wanted to understand. I don't have any preferences.

 In other words, in short: spec says that ITS is optional, so we can implement 
it as a separate component, which gets attached to the GIC using some specified 
interface. It's not a problem to design such an interface. Actually, i believe 
real HW does the same thing.
 In my RFC i have implemented a part of this interface. My ITS class has 
gic-parent property, which is used to attach it to the GIC. KVM implementation 
fetches vGIC's fd from there, while software emulation can use it to call LPI 
methods on the GIC. The property is declared as implementation-specific only 
because it would have different object type, for additional fail-safety. 
Software-emulated ITS cannot be attached to KVM vGIC and vice versa, actually 
only because kernel guys don't want direct LPI injection.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia