From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:43421)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <bounces@canonical.com>) id 1aYJlc-0001pU-T6
	for qemu-devel@nongnu.org; Tue, 23 Feb 2016 15:41:12 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <bounces@canonical.com>) id 1aYJlb-0001P0-R6
	for qemu-devel@nongnu.org; Tue, 23 Feb 2016 15:41:08 -0500
Received: from indium.canonical.com ([91.189.90.7]:59371)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <bounces@canonical.com>) id 1aYJlb-0001Ot-LX
	for qemu-devel@nongnu.org; Tue, 23 Feb 2016 15:41:07 -0500
Received: from loganberry.canonical.com ([91.189.90.37])
	by indium.canonical.com with esmtp (Exim 4.76 #1 (Debian))
	id 1aYJla-0003hK-OW
	for <qemu-devel@nongnu.org>; Tue, 23 Feb 2016 20:41:06 +0000
Received: from loganberry.canonical.com (localhost [127.0.0.1])
	by loganberry.canonical.com (Postfix) with ESMTP id 452172E80CD
	for <qemu-devel@nongnu.org>; Tue, 23 Feb 2016 20:41:06 +0000 (UTC)
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
Date: Tue, 23 Feb 2016 20:34:27 -0000
From: Louis Bouchard <louis.bouchard@canonical.com>
Sender: bounces@canonical.com
References: <20160217094237.24220.45325.malonedeb@chaenomeles.canonical.com>
Message-Id: <20160223203428.2290.45433.launchpad@gac.canonical.com>
Errors-To: bounces@canonical.com
Subject: [Qemu-devel] [Bug 1546445] Re: support vhost user without
	specifying vhostforce
Reply-To: Bug 1546445 <1546445@bugs.launchpad.net>
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: qemu-devel@nongnu.org

** Changed in: qemu (Ubuntu Vivid)
       Status: New =3D> Won't Fix

** No longer affects: qemu (Ubuntu Trusty)

-- =

You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1546445

Title:
  support vhost user without specifying vhostforce

Status in Ubuntu Cloud Archive:
  New
Status in QEMU:
  In Progress
Status in qemu package in Ubuntu:
  New
Status in qemu source package in Vivid:
  Won't Fix
Status in qemu source package in Wily:
  Fix Released

Bug description:
  [Impact]

   * vhost-user falls back to virtio-net which causes performance lose
  without specifying the vhostforce option. But it should be the default
  behavior for vhost-user, since guests using PMD doesn't support msi-x.

  [Test Case]

    create a vhost-user virtio backend without specifying the vhostforce op=
tion, i.e. -netdev type=3Dvhost-user,id=3Dmynet1,chardev=3D<char_dev_for_th=
e_controll_channel>
    start the VM
    vhost-user is not enabled

  [Regression Potential]

   * none

  vhost user nic doesn't support non msi guests(like pxe stage) by default.
  Vhost user nic can't fall back to qemu like normal vhost net nic does. So=
 we should
  enable it for non msi guests.

  The problem has been fix in qemu upstream  -
  http://git.qemu.org/?p=3Dqemu.git;a=3Dcommitdiff;h=3D24f938a682d934b13386=
3eb421aac33592f7a09e.
  And the patch needs to be backported to 1:2.2+dfsg-5expubuntu9.8 .

To manage notifications about this bug go to:
https://bugs.launchpad.net/cloud-archive/+bug/1546445/+subscriptions