Re: [Qemu-devel] [PATCH 2/6] kvm: Rename kvm_irqchip_set_irq to kvm_inject_async_irq

[Avi Kivity]

On 07/25/2012 07:28 PM, Jan Kiszka wrote:
> On 2012-07-25 18:24, Peter Maydell wrote:
>> On 25 July 2012 17:18, Peter Maydell <address@hidden> wrote:
>>> Not in the sense of "you need to KVM_CREATE_IRQCHIP it",
>> 
>> ...incidentally I was thinking about maybe moving kvm_irqchip_create()
>> from being called by kvm_init() to being called by the device
>> init function for the relevant irqchip (particularly we'll need
>> to do that if we adopt Avi's suggestion of having a parameter
>> to KVM_CREATE_IRQCHIP to specify a particular kind of irqchip).
>> But that's more invasive surgery so I didn't want to do it yet.
> 
> This won't fly as irchip affects the whole orchestra (vcpus & irqchip
> stubs in user space), at least on x86, and has to be called in the
> current order. That's also why kernel_irqchip is a machine options, not
> an option of one of the many device models.

Yes, to elaborate, KVM_CREATE_IRQCHIP creates N+3 devices: N local APICs
(deferred until N vcpus are created), one IOAPIC, and two PICs.

We debated decoupling those devices, but since there are a lot of
intercommunication among those devices, it was deemed to difficult (plus
these were the early kvm days when we had different get it in/get it
right tradeoffs).

-- 
error compiling committee.c: too many arguments to function