From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932280Ab0FBJx4 (ORCPT ); Wed, 2 Jun 2010 05:53:56 -0400 Received: from 8bytes.org ([88.198.83.132]:39815 "EHLO 8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757040Ab0FBJxz (ORCPT ); Wed, 2 Jun 2010 05:53:55 -0400 Date: Wed, 2 Jun 2010 11:53:54 +0200 From: Joerg Roedel To: Tom Lyon Cc: Alex Williamson , Avi Kivity , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, chrisw@sous-sol.org, hjk@linutronix.de, gregkh@suse.de, aafabbri@cisco.com, scofeldm@cisco.com Subject: Re: [PATCH] VFIO driver: Non-privileged user level PCI drivers Message-ID: <20100602095354.GE964@8bytes.org> References: <20100530121944.GH27611@redhat.com> <4C04E0E0.3070006@redhat.com> <1275452987.16980.24.camel@x201> <201006012159.41344.pugs@lyon-about.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201006012159.41344.pugs@lyon-about.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 01, 2010 at 09:59:40PM -0700, Tom Lyon wrote: > This is just what I was thinking. But rather than a get/set, just use two fds. > > ioctl(vfio_fd1, VFIO_SET_DOMAIN, vfio_fd2); > > This may fail if there are really 2 different IOMMUs, so user code must be > prepared for failure, In addition, this is strictlyupwards compatible with > what is there now, so maybe we can add it later. How can this fail with multiple IOMMUs? This should be handled transparently by the IOMMU driver. Joerg