On Sat, 2013-05-25 at 07:21 -0400, Konrad Rzeszutek Wilk wrote: > 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 ?
Yeah, that's probably a reasonable feature. intel-iommu has a boot option to disable superpages, but we could make it more consistent at the vfio level if we have a switch there. It could provided interesting performance and debugging info. I'll add a module option to do this. Thanks, Alex > > 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@lists.linux-foundation.org > > https://lists.linuxfoundation.org/mailman/listinfo/iommu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
