From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: PCIPT: VT-d support Date: Mon, 14 Jul 2008 11:48:15 +0300 Message-ID: <487B12CF.4040108@qumranet.com> References: <1215681282-3449-1-git-send-email-benami@il.ibm.com> <200807101730.26586.sheng.yang@intel.com> <1215683513.31546.175.camel@cluwyn.haifa.ibm.com> <200807101807.28719.sheng.yang@intel.com> <20080710144124.GD7273@il.ibm.com> <48762374.3000002@qumranet.com> <20080710160047.GE7273@il.ibm.com> <4879AFFC.8000004@qumranet.com> <1216021776.31546.210.camel@cluwyn.haifa.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Muli Ben-Yehuda , "Yang, Sheng" , kvm@vger.kernel.org, amit.shah@qumranet.com, weidong.han@intel.com, anthony@codemonkey.ws, "Kay, Allen M" To: Ben-Ami Yassour Return-path: Received: from il.qumranet.com ([212.179.150.194]:45845 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755015AbYGNIsR (ORCPT ); Mon, 14 Jul 2008 04:48:17 -0400 In-Reply-To: <1216021776.31546.210.camel@cluwyn.haifa.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: Ben-Ami Yassour wrote: > On Sun, 2008-07-13 at 10:34 +0300, Avi Kivity wrote: > >> Muli Ben-Yehuda wrote: >> >>>> On the other hand, this means that you will not be able to assign >>>> devices unless you specified this when creating the VM; but I think >>>> this is fair. >>>> >>>> >>> It will be nice to support hot-plugged pass-through devices some time >>> in the future. >>> >>> >>> >> And it should be easy to do too. The question is whether we need to >> allocate the iommu domain up front (which would mean that a command line >> parameter would be needed, meaning roughly 'support pci device >> assignment on this guest'. Kind of like -usb, which means 'support usb >> device assignment on this guest'. >> >> > > I don't think that its that simple... > On a single machine you can have multiple iommu units, each of which controls certain PCI slots. > To configure the iommu for a specific device you need to configure the iommu unit that controls that device. > This means that we need to know the bus/dev/func of the device before we create the VT-d domain. > For hot-plug devices it means that by the time we can create the domain we already have memory slots that we need to add to the VT-d mapping. > > Thanks for the info. Looks like we have to support both memslot-before-iommu and memslot-after-iommu then. -- error compiling committee.c: too many arguments to function