From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=55939 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1PAeXk-0005VS-Gw
	for qemu-devel@nongnu.org; Tue, 26 Oct 2010 04:06:05 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <avi@redhat.com>) id 1PAeXg-00065v-I5
	for qemu-devel@nongnu.org; Tue, 26 Oct 2010 04:06:04 -0400
Received: from mx1.redhat.com ([209.132.183.28]:52220)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <avi@redhat.com>) id 1PAeXg-00065i-Af
	for qemu-devel@nongnu.org; Tue, 26 Oct 2010 04:06:00 -0400
Message-ID: <4CC68BE1.5010207@redhat.com>
Date: Tue, 26 Oct 2010 10:05:53 +0200
From: Avi Kivity <avi@redhat.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH 1/2] Type-safe ioport callbacks
References: <1287934469-16624-1-git-send-email-avi@redhat.com>
	<1287934469-16624-2-git-send-email-avi@redhat.com>
	<AANLkTikh=Axbo9PEf5OuFpVq-_PnYxLTXL2PozqZ5fxf@mail.gmail.com>
	<4CC55554.4060103@redhat.com>
	<AANLkTik8jVgiM665BvsdJesVLE4A2Vo7V+y82APC=diw@mail.gmail.com>
In-Reply-To: <AANLkTik8jVgiM665BvsdJesVLE4A2Vo7V+y82APC=diw@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Blue Swirl <blauwirbel@gmail.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org

  On 10/25/2010 08:38 PM, Blue Swirl wrote:
> >
> >  I don't really see why we need registration; cpu_register_io() takes
> >  function pointers, a size, and an opaque, and gives an integer handle in
> >  return.  With the IOPort object approach, you set up the IOPort with
> >  function pointers, size is implied, and the opaque is derived using
> >  container_of(); the handle is simply the address of the object.
>
> With the handle, we can separate setting up the structures at device
> level, and mapping the object using only the handle at bus or other
> higher level. Can this be done with the object approach?

I believe so.  The handle is simply an indirect pointer, no?

> The purpose of that patch series was to perform the separation for PCI
> BARs. I wasn't so happy with the series, so I never pushed.

In fact I think an IOPort is even more suitable; if we need additional 
attributes we can use a derived object:

struct PCIIOPort {
     IOPort ioport;
     /* additional fields */
};



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