From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:51721)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1bk8K1-00037w-DY
	for qemu-devel@nongnu.org; Wed, 14 Sep 2016 07:25:46 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1bk8Jv-0007Dc-7h
	for qemu-devel@nongnu.org; Wed, 14 Sep 2016 07:25:44 -0400
Received: from mx1.redhat.com ([209.132.183.28]:45876)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1bk8Ju-0007DT-VZ
	for qemu-devel@nongnu.org; Wed, 14 Sep 2016 07:25:39 -0400
Date: Wed, 14 Sep 2016 19:25:32 +0800
From: Peter Xu <peterx@redhat.com>
Message-ID: <20160914112532.GA3652@pxdev.xzpeter.org>
References: <1473389864-19694-1-git-send-email-peterx@redhat.com>
	<1473389864-19694-3-git-send-email-peterx@redhat.com>
	<20160914055528.GM15077@voom.fritz.box>
	<20160914071243.GM3776@pxdev.xzpeter.org>
	<20160914072240.GP15077@voom.fritz.box>
	<20160914074941.GO3776@pxdev.xzpeter.org>
	<20160914103734.GQ15077@voom.fritz.box>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20160914103734.GQ15077@voom.fritz.box>
Subject: Re: [Qemu-devel] [PATCH v4 2/3] memory: introduce
 IOMMUOps.notify_flag_changed
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/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: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: qemu-devel@nongnu.org, mst@redhat.com, jasowang@redhat.com, vkaplans@redhat.com, alex.williamson@redhat.com, wexu@redhat.com, pbonzini@redhat.com, cornelia.huck@de.ibm.com, dgibson@redhat.com

On Wed, Sep 14, 2016 at 08:37:34PM +1000, David Gibson wrote:

[...]

> > This should not be related to the interface at all?
> > 
> > I was based on the assumption that "Power cannot support either one of
> > MAP/UNMAP, but only if both exist".
> 
> Huh? I have no idea what you mean by that.
> 
> Power can support notifying both map and unmap events just fine - but
> in order to provide *any* notifications, it has to disable KVM
> acceleration of the guest-side IOMMU (otherwise qemu won't know about
> any changes to the IOMMU state).
> 
> So the change you you suggested before to != IOMMU_NOTIFIER_NONE is
> exactly correct, anything else is not.

Sorry I was wrong. Yes user can register with only one (MAP or UNMAP)
notifier type for any platform.

Thanks.

-- peterx