Re: [kvm-devel] [PATCH 3/3] virtio PCI device

[Carsten O. <co...@de...>]

Avi Kivity wrote:
> No, definitely not define a hypercall ABI.  The feature bit should say 
> "this device understands a hypervisor-specific way of kicking.  consult 
> your hypervisor manual and cpuid bits for further details.  should you 
> not be satisfied with this method, port io is still available".
...unless you're lucky enough to be on s390 where pio is not available.
I don't see why we'd have two different ways to talk to a virtio 
device. I think we should use a hypercall for interrupt injection, 
without support for grumpy old soldered pci features other than 
HPA-style Lguest PCI bus organization. There are no devices that we 
want to be backward compatible with.