Re: [PATCH 1/2] kvm tools: Fix IRQ assignments

[Sasha Levin <levinsasha928@gmail.com>]

On Fri, 2011-05-06 at 10:29 +0300, Pekka Enberg wrote:
> On Fri, May 6, 2011 at 10:26 AM, Sasha Levin <levinsasha928@gmail.com> wrote:
> > virtio-blk needs a block of 4 IRQs (currently - staticly defined).
> > Giving the initial IRQ of 15 causes breakage when adding more
> > than one device.
> >
> > Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> 
> Can we make the allocation dynamic instead? AFAICT, it could be a simple as
> 
>   int kvm__request_irq(struct kvm *kvm)
>   {
>           return kvm->next_irq++;
>   }
> 
> that's done at device init time and then we'd just add "int irq" to
> the individual struct devices.
> 
>                         Pekka

afaik, we need to have same IRQ pins for devices which may have
different IRQ lines (All virtio-blk share same IRQ pin but different
line, I assume it'll be same with different virtio devices).

So mptable has to manage association between device type and the
corresponding IRQ pin/line assignment, So dynamic assignment will be
more of a call with device type and return IRQ pin + line - which makes
it more complex than just allocating next free IRQ line.

-- 

Sasha.