Re: [PATCH v3 1/8] ARM: KVM: Initial skeleton to compile KVM support

[Avi Kivity <avi@redhat.com>]

On 06/05/2011 07:24 PM, Christoffer Dall wrote:
> On ARM, we are talking about IRQs and FIQs, both of which can be
> lowered and raised. In other words, four values.

Two lines per cpu, each of which can be raised or lowered.

> But instead of this, you want to use KVM_IRQ_LINE and just assume one
> CPU to begin with and always assert/deassert the interrupts on that
> CPU and later, with SMP support, you want to use KVM_SET_GSI_ROUTING
> to control which CPU gets the interrupt - even though GSI is a
> non-existing concept for ARM? (Also, I could not seem to find any use
> of GSI_ROUTING in current upstream QEMU, but I may be missing
> something here?).

Almost.  vcpu N's IRQ -> KVM_IRQ_LINE(N*2, level).  vcpu N's FIQ -> 
KVM_IRQ_LINE(N*2+1, level), + documentation somewhere.

> I suggest I simply use a flag in the irq field on the kvm_interrupt
> struct as suggested by Jan, for now, and if we start emulating GICs
> inside the kernel for ARM we can go the extra mile at that point.
> IMHO, I think the semantics of actually raising an interrup line on
> the VCPU, as opposed to the VM, when it's CPU interrupt we are talking
> about is equally important.

When you implement an interrupt controller, you can use 
KVM_SET_GSI_ROUTING to change the meaning of the parameter to 
KVM_IRQ_LINE to point to the interrupt controllers.

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