From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH 0/2] vfio: type1 iommu hugepage support Date: Sat, 25 May 2013 07:21:54 -0400 Message-ID: <20130525112153.GD2418@localhost.localdomain> References: <20130524171613.14229.84050.stgit@bling.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, chegu_vinod-VXdhtT5mjnY@public.gmane.org, qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alex Williamson Return-path: Content-Disposition: inline In-Reply-To: <20130524171613.14229.84050.stgit-xdHQ/5r00wBBDLzU/O5InQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: kvm.vger.kernel.org On Fri, May 24, 2013 at 11:24:26AM -0600, Alex Williamson wrote: > This series let's the vfio type1 iommu backend take advantage of iommu > large page support. See patch 2/2 for the details. This has been > tested on both amd_iommu and intel_iommu, but only my AMD system has > large page support. I'd appreciate any testing and feedback on other > systems, particularly vt-d systems supporting large pages. Mapping > efficiency should be improved a bit without iommu hugepages, but I > hope that it's much more noticeable with huge pages, especially for > very large QEMU guests. I took a very very quick look - and I am wondering if there should also be a flag to turn it on/off in ther kernel in such case? Especially in the field if a user finds out that their particular IOMMU chipset might be doing something funky with large-pages ? > > This change includes a clarification to the mapping expectations for > users of the type1 iommu, but is compatible with known users and works > with existing QEMU userspace supporting vfio. Thanks, > > Alex > > --- > > Alex Williamson (2): > vfio: Convert type1 iommu to use rbtree > vfio: hugepage support for vfio_iommu_type1 > > > drivers/vfio/vfio_iommu_type1.c | 607 ++++++++++++++++++++++++--------------- > include/uapi/linux/vfio.h | 8 - > 2 files changed, 387 insertions(+), 228 deletions(-) > _______________________________________________ > iommu mailing list > iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu