From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1NA1Lo-0002qI-VS
	for qemu-devel@nongnu.org; Mon, 16 Nov 2009 08:10:37 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1NA1Lk-0002mA-Tc
	for qemu-devel@nongnu.org; Mon, 16 Nov 2009 08:10:36 -0500
Received: from [199.232.76.173] (port=47210 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1NA1Lk-0002lz-Pt
	for qemu-devel@nongnu.org; Mon, 16 Nov 2009 08:10:32 -0500
Received: from mx1.redhat.com ([209.132.183.28]:23769)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <kraxel@redhat.com>) id 1NA1Lk-0008No-88
	for qemu-devel@nongnu.org; Mon, 16 Nov 2009 08:10:32 -0500
Message-ID: <4B014F2D.3040205@redhat.com>
Date: Mon, 16 Nov 2009 14:10:05 +0100
From: Gerd Hoffmann <kraxel@redhat.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] virtio-rng
References: <4AFB2D4D.8050208@collabora.co.uk> <4B011F38.9070500@redhat.com>
	<4B014584.6000001@collabora.co.uk>
In-Reply-To: <4B014584.6000001@collabora.co.uk>
Content-Type: text/plain; charset=ISO-8859-1; 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.gnu.org/pipermail/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: Ian Molton <ian.molton@collabora.co.uk>
Cc: qemu-devel@nongnu.org

On 11/16/09 13:28, Ian Molton wrote:

> I've done something similar (below)
>
> My commandline looks like:
>
> - -virtiorng dev=/dev/foo,rate=1234
>
> I added some properties to my driver which are obviously then filled in
> from the options code, and I do my init like this:

There is no need for a new -virtiorng switch.  qdev allows to set any 
property when creating devices via -device on the command line.

> VirtIODevice *virtio_rng_init(DeviceState *dev, RNGConf *rngdev)
> {
>      VirtIORng *s;
>      s = (VirtIORng *)virtio_common_init("virtio-rng",
>                                              VIRTIO_ID_RNG,
>                                              0, sizeof(VirtIORng));
>
>      if (!s)
>          return NULL;
>
>      s->vdev.get_features = virtio_rng_get_features;
>
>      s->vq = virtio_add_queue(&s->vdev, 128, virtio_rng_handle);
>      s->chr = qemu_chr_open("vrngdev", rngdev->device, NULL);
>
>      ...
>
>      return&s->vdev;
> }
>
> Is this 'not the right way' ? I think the commandline looks much simpler
> this way.

The point is to separate host and guest state.  -chardev ist host state, 
the device is guest state, and they are linked using the chardev name.

> OTOH, I can see that this might help with my next problem, which is that
> I want to write EGD support for virtio-rng, so I'm guessing my
> commandline would (in your scheme) need to be something like:
>
>
>      -tcpsocketthing $addr.of.egd.server,id=some-name-here,
>       more-egd-client-options
>      -device virtio-rng,tcpsocketthing=some-name-here,rate=$limit

Maybe ...

    -chardev socket,id=egd,host=egd.domain.tld,port=whatever
    -device virtio-rng,chardev=egd

... ?

> This doesnt, however, get around my problem that the -device option
> doesnt know how to parse OPT_SIZE types, though. (I'd like to be able to
> specify 'rate' in B/s or KB/s (or even kbits/sec, more appropriately))

Yes, there is no qdev property type (yet) which can parse those 
postfixes.  Which is no reason to not add one though ;)

cheers,
   Gerd