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Date: Wed, 28 Jun 2017 22:32:38 +0800
From: Fam Zheng <famz@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 4/7] qdev: Introduce DEFINE_PROP_LINK
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org, "Dr . David Alan Gilbert" <dgilbert@redhat.com>, Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>

On Wed, 06/28 16:06, Paolo Bonzini wrote:
> 
> 
> On 28/06/2017 16:02, Fam Zheng wrote:
> >>> It's implemented by creating a wrapper property that basically forwards
> >>> operations to a QOM "link-FOO" property, which handles the check
> >>> callback and flags. The feature that is missing from QOM is the dynamic
> >>> child pointer which is done in the added code with the usual "offset"
> >>> approach.
> >> Would it be possible to add a ".create" field to PropertyInfo?  Then
> >> there's no need to introduce the wrapper.
> > QOM setter/getter want a LinkProperty opaque pointer, but qdev uses a Property
> > pointer. I don't see a way to adapt that with .create(). Can you elaborate?
> 
> The .create() callback would call object_property_add_link directly.
> There would be no change in the properties at the QOM level, but the
> PropertyInfo lets "info qtree" show the property.

Thanks, I see, I'll try it in v2 if Andreas agrees on the general idea.

Fam