Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754045AbYLAMAv (ORCPT ); Mon, 1 Dec 2008 07:00:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751755AbYLAMAl (ORCPT ); Mon, 1 Dec 2008 07:00:41 -0500 Received: from outbound-va3.frontbridge.com ([216.32.180.16]:24097 "EHLO VA3EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751057AbYLAMAk (ORCPT ); Mon, 1 Dec 2008 07:00:40 -0500 X-BigFish: VPS-37(ze80iz1418M1432R98dR1805M179dR936fO873fnzzzzz32i6bh43j62h) X-Spam-TCS-SCL: 1:0 X-FB-SS: 5, X-WSS-ID: 0KB75CQ-03-EQR-01 Date: Mon, 1 Dec 2008 13:00:26 +0100 From: Joerg Roedel To: FUJITA Tomonori CC: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, weidong.han@intel.com, mingo@redhat.com, avi@redhat.com, amit.shah@redhat.com Subject: Re: [PATCH 3/9] add frontend implementation for the IOMMU API Message-ID: <20081201120026.GF17719@amd.com> References: <1227800454-9555-4-git-send-email-joerg.roedel@amd.com> <20081128184041N.fujita.tomonori@lab.ntt.co.jp> <20081128113129.GO1386@amd.com> <20081201173830B.fujita.tomonori@lab.ntt.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20081201173830B.fujita.tomonori@lab.ntt.co.jp> User-Agent: mutt-ng/devel-r804 (Linux) X-OriginalArrivalTime: 01 Dec 2008 12:00:26.0921 (UTC) FILETIME=[6619B190:01C953AC] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3111 Lines: 70 On Mon, Dec 01, 2008 at 05:38:11PM +0900, FUJITA Tomonori wrote: > On Fri, 28 Nov 2008 12:31:29 +0100 > Joerg Roedel wrote: > > > On Fri, Nov 28, 2008 at 06:40:41PM +0900, FUJITA Tomonori wrote: > > > On Thu, 27 Nov 2008 16:40:48 +0100 > > > Joerg Roedel wrote: > > > > > > > Signed-off-by: Joerg Roedel > > > > --- > > > > drivers/base/iommu.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > 1 files changed, 94 insertions(+), 0 deletions(-) > > > > create mode 100644 drivers/base/iommu.c > > > > > > > > diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c > > > > new file mode 100644 > > > > index 0000000..7250b9c > > > > --- /dev/null > > > > +++ b/drivers/base/iommu.c > > > > > > Hmm, why is this at drivers/base/? Anyone except for kvm could use > > > this? If so, under virt/ is more appropriate? > > > > I don't see a reason why this should be KVM specific. KVM is the only > > user for now. But it can be used for i.e. UIO too. Or in drivers to > > speed up devices which have bad performance when they do scather gather > > IO. > > If there are some except for kvm that could use this, it should be > fine, I guess. > > Can you add such information (e.g. who could use this) to the patch > description? It should be in the git log if the patch is merged. Ok, I will add it. > > > The majority of the names (include/linux/iommu.h, iommu.c, iommu_ops, > > > etc) looks too generic? We already have lots of similar things > > > (e.g. arch/{x86,ia64}/asm/iommu.h, several archs' iommu.c, etc). Such > > > names are expected to be used by all the IOMMUs. > > > > The API is already useful for more than KVM. I also plan to extend it to > > support more types of IOMMUs than VT-d and AMD IOMMU in the future. But > > these changes are more intrusive than this patchset and need more > > discussion. I prefer to do small steps into this direction. > > Can you be more specific? What IOMMU could use this? For example, how > GART can use this? I think that people expect the name 'struct > iommu_ops' to be an abstract for all the IOMMUs (or the majority at > least). If this works like that, the name is a good choice, I think. GART can't use exactly this. But with some extensions we can make it useful for GART and GART-like IOMMUs too. For example we can emulate domains in GART by partitioning the GART aperture space. Joerg -- | AMD Saxony Limited Liability Company & Co. KG Operating | Wilschdorfer Landstr. 101, 01109 Dresden, Germany System | Register Court Dresden: HRA 4896 Research | General Partner authorized to represent: Center | AMD Saxony LLC (Wilmington, Delaware, US) | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/