From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Roedel, Joerg" Subject: Re: kvm PCI assignment & VFIO ramblings Date: Wed, 24 Aug 2011 11:14:26 +0200 Message-ID: <20110824091425.GE2079@amd.com> References: <20110823110431.GK2079@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Benjamin Herrenschmidt , Alexey Kardashevskiy , "kvm@vger.kernel.org" , Paul Mackerras , "linux-pci@vger.kernel.org" , qemu-devel , iommu , chrisw , Avi Kivity , Anthony Liguori , linuxppc-dev , "benve@cisco.com" To: aafabbri Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-pci-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Tue, Aug 23, 2011 at 12:54:27PM -0400, aafabbri wrote: > On 8/23/11 4:04 AM, "Joerg Roedel" wrote: > > That is makes uiommu basically the same as the meta-groups, right? > > Yes, functionality seems the same, thus my suggestion to keep uiommu > explicit. Is there some need for group-groups besides defining sets of > groups which share IOMMU resources? > > I do all this stuff (bringing up sets of devices which may share IOMMU > domain) dynamically from C applications. I don't really want some static > (boot-time or sysfs fiddling) supergroup config unless there is a good > reason KVM/power needs it. > > As you say in your next email, doing it all from ioctls is very easy, > programmatically. I don't see a reason to make this meta-grouping static. It would harm flexibility on x86. I think it makes things easier on power but there are options on that platform to get the dynamic solution too. Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632