From mboxrd@z Thu Jan 1 00:00:00 1970 From: Muli Ben-Yehuda Subject: Re: VT-d support for device assignment Date: Fri, 22 Aug 2008 21:28:10 +0300 Message-ID: <20080822182810.GI6885@il.ibm.com> References: <1219389054-15332-1-git-send-email-amit.shah@qumranet.com> <48AF039B.7040805@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Amit Shah , kvm@vger.kernel.org, anthony@codemonkey.ws, jesse.barnes@intel.com, david.woodhouse@intel.com, mark.gross@intel.com, Ben-Ami Yassour1 , weidong.han@intel.com To: Avi Kivity Return-path: Received: from mtagate4.uk.ibm.com ([195.212.29.137]:47272 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755695AbYHVS2R (ORCPT ); Fri, 22 Aug 2008 14:28:17 -0400 Received: from d06nrmr1407.portsmouth.uk.ibm.com (d06nrmr1407.portsmouth.uk.ibm.com [9.149.38.185]) by mtagate4.uk.ibm.com (8.13.8/8.13.8) with ESMTP id m7MISGqn262522 for ; Fri, 22 Aug 2008 18:28:16 GMT Received: from d06av02.portsmouth.uk.ibm.com (d06av02.portsmouth.uk.ibm.com [9.149.37.228]) by d06nrmr1407.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m7MISFBf3960894 for ; Fri, 22 Aug 2008 19:28:16 +0100 Received: from d06av02.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av02.portsmouth.uk.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m7MISFTo030116 for ; Fri, 22 Aug 2008 19:28:15 +0100 Content-Disposition: inline In-Reply-To: <48AF039B.7040805@qumranet.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Aug 22, 2008 at 09:21:15PM +0300, Avi Kivity wrote: > You mean, iommu=on. Agreed. This should also be the default if not dma=xxx is specfied and a capable IOMMU is found. > Or rather > > dma=iommu > dma=none (1:1 mapping, or dma-less devices, or I'm Feeling Lucky) > dma=cooperative (paravirt) What does the 'cooperative' mean? I assume you are thinking of PVDMA-without-IOMMU, but in that case the name is misleading, since you can do cooperative (PVDMA) just fine with an IOMMU. Perhaps "dma=itrusttheguest", since with PVDMA0-without-IOMMU the guest is trusted to not screw up the system? Cheers, Muli -- Workshop on I/O Virtualization (WIOV '08) Co-located with OSDI '08, Dec 2008, San Diego, CA http://www.usenix.org/wiov08