Re: [PATCH 4/6] KVM: Add kvm_get_irq_routing_entry() func

[Avi Kivity <avi@redhat.com>]

On 11/15/2010 11:15 AM, Sheng Yang wrote:
> We need to query the entry later.
>
> +int kvm_get_irq_routing_entry(struct kvm *kvm, int gsi,
> +		struct kvm_kernel_irq_routing_entry *entry)
> +{
> +	int count = 0;
> +	struct kvm_kernel_irq_routing_entry *ei = NULL;
> +	struct kvm_irq_routing_table *irq_rt;
> +	struct hlist_node *n;
> +
> +	rcu_read_lock();
> +	irq_rt = rcu_dereference(kvm->irq_routing);
> +	if (gsi<  irq_rt->nr_rt_entries)
> +		hlist_for_each_entry(ei, n,&irq_rt->map[gsi], link)
> +			count++;
> +	if (count == 1)
> +		*entry = *ei;
> +	rcu_read_unlock();
> +
> +	return (count != 1);
> +}
> +

Not good form to rely on ei being valid after the loop.

I guess this is only useful for msi?  Need to document it.

*entry may be stale after rcu_read_unlock().  Is this a problem?

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