From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 4/6] KVM: Add kvm_get_irq_routing_entry() func
Date: Wed, 17 Nov 2010 16:01:41 +0200
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References: <1289812532-3227-1-git-send-email-sheng@linux.intel.com> <1289812532-3227-5-git-send-email-sheng@linux.intel.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>, kvm@vger.kernel.org
To: Sheng Yang <sheng@linux.intel.com>
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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