From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:36470)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1WV09X-0002OZ-95
	for qemu-devel@nongnu.org; Tue, 01 Apr 2014 10:59:10 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1WV09O-0003ZJ-P6
	for qemu-devel@nongnu.org; Tue, 01 Apr 2014 10:59:03 -0400
Received: from cantor2.suse.de ([195.135.220.15]:35230 helo=mx2.suse.de)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1WV09O-0003Yh-Is
	for qemu-devel@nongnu.org; Tue, 01 Apr 2014 10:58:54 -0400
Message-ID: <533AD42D.8060504@suse.de>
Date: Tue, 01 Apr 2014 16:58:53 +0200
From: Alexander Graf <agraf@suse.de>
MIME-Version: 1.0
References: <1396363663-50450-1-git-send-email-borntraeger@de.ibm.com>
	<1396363663-50450-2-git-send-email-borntraeger@de.ibm.com>
In-Reply-To: <1396363663-50450-2-git-send-email-borntraeger@de.ibm.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH/RFC] KVM: s390: Add S390 configuration and
 control kvm device
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: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-s390 <linux-s390@vger.kernel.org>, Michael Mueller <mimu@linux.vnet.ibm.com>, KVM <kvm@vger.kernel.org>, Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>, qemu-devel <qemu-devel@nongnu.org>, Jens Freimann <jfrei@linux.vnet.ibm.com>, Cornelia Huck <cornelia.huck@de.ibm.com>

On 04/01/2014 04:47 PM, Christian Borntraeger wrote:
> From: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
>
> Add KVM_DEV_TYPE_S390_CONFIG kvm device that contains
> configuration and control attributes of particular vm.
> The device is created by KVM_CREATE_DEVICE ioctl.
> The attributes may be retrieved and stored by calling
> KVM_GET_DEVICE_ATTR and KVM_SET_DEVICE_ATTR ioctls.
>
> Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

I don't think a device is particularly the best fit. A device can 
usually be instantiated multiple times. The configuration device can 
only be created once. A device also gets created by user space which 
enables it to receive the fd to drive it. Your device has to be created 
during VM creation.

I think VM configuration is common enough to just make this a separate 
interface.


Alex