From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <alan.carew@intel.com>
Received: from mga01.intel.com (mga01.intel.com [192.55.52.88])
 by dpdk.org (Postfix) with ESMTP id 0F1952E89
 for <dev@dpdk.org>; Mon, 10 Nov 2014 09:57:42 +0100 (CET)
Received: from fmsmga003.fm.intel.com ([10.253.24.29])
 by fmsmga101.fm.intel.com with ESMTP; 10 Nov 2014 01:06:43 -0800
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="414134954"
Received: from irsmsx102.ger.corp.intel.com ([163.33.3.155])
 by FMSMGA003.fm.intel.com with ESMTP; 10 Nov 2014 00:57:54 -0800
Received: from irsmsx153.ger.corp.intel.com (163.33.192.75) by
 IRSMSX102.ger.corp.intel.com (163.33.3.155) with Microsoft SMTP Server (TLS)
 id 14.3.195.1; Mon, 10 Nov 2014 09:05:58 +0000
Received: from irsmsx109.ger.corp.intel.com ([169.254.13.101]) by
 IRSMSX153.ger.corp.intel.com ([169.254.9.23]) with mapi id 14.03.0195.001;
 Mon, 10 Nov 2014 09:05:57 +0000
From: "Carew, Alan" <alan.carew@intel.com>
To: Thomas Monjalon <thomas.monjalon@6wind.com>
Thread-Topic: [dpdk-dev] [PATCH v4 00/10] VM Power Management
Thread-Index: AQHP5lPntegTcHXUhU2lJ6crRCq8n5wuan2AgAEcXMCAABvQgIABq4twgBRqtQCAFAP74A==
Date: Mon, 10 Nov 2014 09:05:56 +0000
Message-ID: <0E29434AEE0C3A4180987AB476A6F6306D28E7DF@IRSMSX109.ger.corp.intel.com>
References: <1412003903-9061-1-git-send-email-alan.carew@intel.com>
 <3349663.LNtcecTXb3@xps13>
 <0E29434AEE0C3A4180987AB476A6F6306D2811AD@IRSMSX109.ger.corp.intel.com>
 <1804867.TWdiCQc2JQ@xps13>
In-Reply-To: <1804867.TWdiCQc2JQ@xps13>
Accept-Language: en-IE, en-US
Content-Language: en-US
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
x-originating-ip: [163.33.239.180]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v4 00/10] VM Power Management
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Mon, 10 Nov 2014 08:57:44 -0000

Hi Thomas,

> Hi Alan,
>=20
> Did you make any progress in Qemu/KVM community?
> We need to be sync'ed up with them to be sure we share the same goal.
> I want also to avoid using a solution which doesn't fit with their plan.
> Remember that we already had this problem with ivshmem which was
> planned to be dropped.
>=20
> Thanks
> --
> Thomas
>=20
>=20
> 2014-10-16 15:21, Carew, Alan:
> > Hi Thomas,
> >
> > > > However with a DPDK solution it would be possible to re-use the
> message bus
> > > > to pass information like device stats, application state, D-state r=
equests
> > > > etc. to the host and allow for management layer(e.g. OpenStack) to
> make
> > > > informed decisions.
> > >
> > > I think that management informations should be transmitted in a
> management
> > > channel. Such solution should exist in OpenStack.
> >
> > Perhaps it does, but this solution is not exclusive to OpenStack and ju=
st a
> potential use case.
> >
> > >
> > > > Also, the scope of adding power management to qemu/KVM would be
> huge;
> > > > while the easier path is not always the best and the problem of pow=
er
> > > > management in VMs is both a DPDK problem (given that librte_power
> only
> > > > worked on the host) and a general virtualization problem that would=
 be
> > > > better solved by those with direct knowledge of Qemu/KVM
> architecture
> > > > and influence on the direction of the Qemu project.
> > >
> > > Being a huge effort is not an argument.
> >
> > I agree completely and was implied by what followed the conjunction.
> >
> > > Please check with Qemu community, they'll welcome it.
> > >
> > > > As it stands, the host backend is simply an example application tha=
t can
> > > > be replaced by a VMM or Orchestration layer, by using Virtio-Serial=
 it
> has
> > > > obvious leanings to Qemu, but even this could be easily swapped out
> for
> > > > XenBus, IVSHMEM, IP etc.
> > > >
> > > > If power management is to be eventually supported by Hypervisors
> directly
> > > > then we could also enable to option to switch to that environment,
> currently
> > > > the librte_power implementations (VM or Host) can be selected
> dynamically
> > > > (environment auto-detection) or explicitly via rte_power_set_env(),
> adding
> > > > an arbitrary number of environments is relatively easy.
> > >
> > > Yes, you are adding a new layer to workaround hypervisor lacks. And t=
his
> layer
> > > will handle native support when it will exist. But if you implement n=
ative
> > > support now, we don't need this extra layer.
> >
> > Indeed, but we have a solution implemented now and yes it is a
> workaround, that is until Hypervisors support such functionality. It is p=
ossible
> that whatever solutions for power management present themselves in the
> future may require workarounds also, us-vhost is an example of such a
> workaround introduced to DPDK.
> >
> > >
> > > > I hope this helps to clarify the approach.
> > >
> > > Thanks for your explanation.
> >
> > Thanks for the feedback.
> >
> > >
> > > --
> > > Thomas
> >
> > Alan.

Unfortunately, I have not yet received any feedback:
http://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg01103.html

Alan.