From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 0F1952E89 for ; 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" To: Thomas Monjalon 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" 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-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.