Re: [Qemu-devel] [PATCH 1/2] kvm irqfd: support msimessage to irq translation in PHB

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/27/2013 08:32 PM, Benjamin Herrenschmidt wrote:
> On Tue, 2013-08-27 at 13:26 +0300, Michael S. Tsirkin wrote:
>> e would end up with something like
>>>
>>> diff --git a/kvm-all.c b/kvm-all.c
>>> index 716860f..ca3251e 100644
>>> --- a/kvm-all.c
>>> +++ b/kvm-all.c
>>> @@ -1190,6 +1190,10 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
>>>      struct kvm_irq_routing_entry kroute = {};
>>>      int virq;
>>>
>>> +    if (kvm_gsi_routing_linear()) {
>>> +        return msi.data & 0xffff;
>>> +    }
>>> +
> 
> I haven't followed the whole discussion, Alexey, is this the per-host
> bridge source number or the global XIRR (XICS interrupt number) ?

When I started this topic, that was per bridge and this is why I changed it
to be global and eventually this spapr-MSIX fix reached agraf/ppc-next
(happened last week) so the fix above should just work now.


> Because in the latter case, it can be up to 24 bits... (And yes, MSI
> data is limited to 16).

Yes, this is the main limitation here.

> However maybe we can decide arbitrarily that under qemu/kvm we only
> support 16-bit XIRRs (it's fine, from a PAPR perspective at least if it
> keep things simpler).

I'll keep 0xffff then as everybody is happy with this.


-- 
Alexey