From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1MEn25-0006K7-Cx
	for qemu-devel@nongnu.org; Thu, 11 Jun 2009 12:21:41 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1MEn21-0006B1-Rt
	for qemu-devel@nongnu.org; Thu, 11 Jun 2009 12:21:41 -0400
Received: from [199.232.76.173] (port=50989 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1MEn21-0006As-Od
	for qemu-devel@nongnu.org; Thu, 11 Jun 2009 12:21:37 -0400
Received: from mx2.redhat.com ([66.187.237.31]:32805)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <amit.shah@redhat.com>) id 1MEn21-0000dj-CQ
	for qemu-devel@nongnu.org; Thu, 11 Jun 2009 12:21:37 -0400
Date: Thu, 11 Jun 2009 21:51:30 +0530
From: Amit Shah <amit.shah@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] virtio-serial: PCI device for simple host
	<-> guest communication
Message-ID: <20090611162129.GA19119@amit-x200.pnq.redhat.com>
References: <1244565768-9103-1-git-send-email-amit.shah@redhat.com>
	<1244565768-9103-2-git-send-email-amit.shah@redhat.com>
	<1244565768-9103-3-git-send-email-amit.shah@redhat.com>
	<1244565768-9103-4-git-send-email-amit.shah@redhat.com>
	<20090609181714.GB11485@amd.home.annexia.org>
	<4A2EB079.6020909@codemonkey.ws>
	<20090611135155.GA13426@amit-x200.pnq.redhat.com>
	<f43fc5580906110907h341a4237pafefdfcac4e4b9ee@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <f43fc5580906110907h341a4237pafefdfcac4e4b9ee@mail.gmail.com>
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: Blue Swirl <blauwirbel@gmail.com>
Cc: "Richard W.M. Jones" <rjones@redhat.com>, qemu-devel@nongnu.org

On (Thu) Jun 11 2009 [19:07:26], Blue Swirl wrote:
> On 6/11/09, Amit Shah <amit.shah@redhat.com> wrote:
> > On (Tue) Jun 09 2009 [13:56:57], Anthony Liguori wrote:
> >  > Richard W.M. Jones wrote:
> >  >> On Tue, Jun 09, 2009 at 10:12:48PM +0530, Amit Shah wrote:
> >  >> [...]
> >  >>
> >  >> Are you going to post the virtio driver for the Linux kernel later?
> >  >>
> >  >
> >  > Yeah, I'd like to see the Linux driver before drawing conclusions.
> >
> >  Pasting here a slightly older version of the patch. I'm actively working
> >  on it; a few things might have changed but the basic idea remains the
> >  same.
> 
> >  + * along with this program; if not, write to the Free Software
> >  + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> 
> Old FSF address, the new one is on Franklin St.

OK, will update.

> >  +struct virtio_serial_port {
> 
> >  +       unsigned int read_len;
> 
> This limits the maximum transfer length to 4G, which is way too short
> on 64 bit hosts. ;-)

This is only valid for a single packet that's transmitted via the queue
at a time and I doubt anyone's going to use bigger packets :-)

(That size is also limited by the kernel -- and the current code only
alloctes one PAGE_SIZE buffer for the transfer.)

> >  +struct virtio_serial_config {
> >  +       __u8 nr_ports;
> >  +       __u16 status;
> >  +} __attribute__((packed));
> 
> The structure should be redesigned to work without packed attribute.
> status field is unaligned.

I'll see how to untangle it.

		Amit