Re: [PATCH 1/2] kvm: libkvm: support for irq routing

Sheng Yang
2009-01-15T10:05:06Z

On Thursday 15 January 2009 17:59:43 Avi Kivity wrote:
> Sheng Yang wrote:
> > On Thursday 15 January 2009 14:17:16 Sheng Yang wrote:
> >> On Wednesday 14 January 2009 21:53:10 Avi Kivity wrote:
> >>> Signed-off-by: Avi Kivity <avi@redhat.com>
> >>
> >> Do we need a lock for the table?
> >
> > And kvm_add_irq_route/kvm_del_irq_route should be generic used, how about
> > transfer a kvm_irq_routing_entry as parameter?
>
> These structures + selectors + unions are clumsy. For libkvm, I'd
> prefer adding kvm_add_msi() and kvm_del_msi().

But...
> +int kvm_add_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin)
> +{
> +#ifdef KVM_CAP_IRQ_ROUTING
> +       struct kvm_irq_routing *z;
> +       struct kvm_irq_routing_entry *e;
> +       int n, size;
> +
> +       if (kvm->irq_routes->nr == kvm->nr_allocated_irq_routes) {
> +               n = kvm->nr_allocated_irq_routes * 2;
> +               if (n < 64)
> +                       n = 64;
> +               size = sizeof(struct kvm_irq_routing);
> +               size += n * sizeof(*e);
> +               z = realloc(kvm->irq_routes, size);
> +               if (!z)
> +                       return -ENOMEM;
> +               kvm->nr_allocated_irq_routes = n;
> +               kvm->irq_routes = z;
> +       }
> +       n = kvm->irq_routes->nr++;
> +       e = &kvm->irq_routes->entries[n];
> +       memset(e, 0, sizeof(*e));
> +       e->gsi = gsi;
> +       e->type = KVM_IRQ_ROUTING_IRQCHIP;
> +       e->flags = 0;
> +       e->u.irqchip.irqchip = irqchip;
> +       e->u.irqchip.pin = pin;
> +       return 0;
> +#else
> +       return -ENOSYS;
> +#endif
> +}

Besides three lines, all can be reused... I don't see the reason for another
function...

And the name here is irq_route, I suppose it should be generic used. Can be
core function which can be wrapped.

--
regards
Yang, Sheng