From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark McLoughlin <markmc@redhat.com>
Subject: Re: [PATCH 3/4] KVM: gracefully handle zero in
	kvm_free_irq_source_id()
Date: Mon, 01 Dec 2008 13:56:57 +0000
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Cc: kvm@vger.kernel.org, Sheng Yang <sheng@linux.intel.com>
To: Avi Kivity <avi@redhat.com>
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On Sun, 2008-11-30 at 12:28 +0200, Avi Kivity wrote:
> Mark McLoughlin wrote:
> > Allow kvm_free_irq_source_id() to be called with a zero ID.
> >
> > Zero is reserved for KVM_USERSPACE_IRQ_SOURCE_ID, so we can
> > guarantee that kvm_request_irq_source_id() will never return
> > zero and use zero to indicate "no source ID allocated".
> >
> >   
> 
> Zero is a legal value for irq source ids, overloading it as something 
> else is confusing.

Fair enough; I choose zero because it's naturally initialised to that by
the kzalloc(). But I prefer explicit initialisation anyway, so ...

> Things should continue to work if we #define it to 17.

Okay, let's try with -1 then.

> > +	ASSERT(irq_source_id != 0); /* KVM_USERSPACE_IRQ_SOURCE_ID reserved */
> >   
> 
> Why not replace 0 with the actual symbolic constant?

Because I was giving 0 two meanings :-)

Respin of the patches coming up.

Cheers,
Mark.