From mboxrd@z Thu Jan 1 00:00:00 1970 From: Muli Ben-Yehuda Subject: Re: IOMMU setting Date: Sat, 4 Apr 2009 21:18:23 +0300 Message-ID: <20090404181823.GC9168@il.ibm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Eric Liu Return-path: Received: from mtagate4.de.ibm.com ([195.212.29.153]:62571 "EHLO mtagate4.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754272AbZDDSUy (ORCPT ); Sat, 4 Apr 2009 14:20:54 -0400 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate4.de.ibm.com (8.14.3/8.13.8) with ESMTP id n34IKpDs123466 for ; Sat, 4 Apr 2009 18:20:51 GMT Received: from d12av04.megacenter.de.ibm.com (d12av04.megacenter.de.ibm.com [9.149.165.229]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n34IKpRp4186134 for ; Sat, 4 Apr 2009 20:20:51 +0200 Received: from d12av04.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av04.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n34IKpQp015363 for ; Sat, 4 Apr 2009 20:20:51 +0200 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Sat, Apr 04, 2009 at 12:16:50AM +0000, Eric Liu wrote: > > Is there a quick way to check if system has IOMMU enabled in Linux? > > I saw the following messages in /var/log/messages: > > Apr 3 21:03:16 kernel: PCI-DMA: Disabling AGP. > Apr 3 21:03:16 kernel: PCI-DMA: aperture base @ f4000000 size 65536 KB > Apr 3 21:03:16 kernel: init_memory_mapping: 00000000f4000000-00000000f8000000 > Apr 3 21:03:16 kernel: last_map_addr: f8000000 end: f8000000 > Apr 3 21:03:16 kernel: PCI-DMA: using GART IOMMU. > Apr 3 21:03:16 kernel: PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture > > Does this mean IOMMU is enabed? And i don't need anything like > iommu=force in boot option, right? It means that you are running on an AMD system, and that this system has a GART. You need an isolation-capable IOMMU such as Intel's VT-d for KVM in-tree device passthrough. Cheers, Muli -- Muli Ben-Yehuda | muli@il.ibm.com | +972-4-8281080 Manager, Virtualization and Systems Architecture Master Inventor, IBM Haifa Research Laboratory SYSTOR 2009---The Israeli Experimental Systems Conference http://www.haifa.il.ibm.com/conferences/systor2009/