From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56729) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dTGDm-0004zp-08 for qemu-devel@nongnu.org; Thu, 06 Jul 2017 19:30:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dTGDl-0003ZR-4w for qemu-devel@nongnu.org; Thu, 06 Jul 2017 19:30:06 -0400 Date: Fri, 7 Jul 2017 02:29:51 +0300 From: "Michael S. Tsirkin" Message-ID: <20170707022732-mutt-send-email-mst@kernel.org> References: <6f22079e-4b4b-6476-77be-51ec83104c0d@redhat.com> <8a7fb667-e6c0-2412-6dca-a8233dd27836@redhat.com> <15b631c8-5708-1426-90a2-9be51a796614@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [Qemu-arm] [RFC v2 0/8] VIRTIO-IOMMU device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Kalra, Ashish" Cc: Auger Eric , Bharat Bhushan , Jean-Philippe Brucker , "eric.auger.pro@gmail.com" , "peter.maydell@linaro.org" , "alex.williamson@redhat.com" , "qemu-arm@nongnu.org" , "qemu-devel@nongnu.org" , "kevin.tian@intel.com" , "marc.zyngier@arm.com" , "tn@semihalf.com" , "will.deacon@arm.com" , "drjones@redhat.com" , "robin.murphy@arm.com" , "christoffer.dall@linaro.org" On Thu, Jul 06, 2017 at 11:23:41PM +0000, Kalra, Ashish wrote: > I have a generic question on vIOMMU support, is there any proposal/plan to add ATS/PRI extension support to vIOMMUs and allow > handling for end to end (v)IOMMU Page faults (w/t the device side implementation on Vhost) ? > > Again, the motivation will be to do DMA on paged guest memory and potentially avoiding the requirement of pinned/locked > guest physical memory for DMA. > > Thanks, > Ashish If that's your goal, first step would be support in VFIO. End to end would only be helpful when running userspace drivers within guest, or nested virt. -- MST