From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [RFC 0/6] vSMMU initialization Date: Fri, 12 Jun 2015 15:23:29 +0100 Message-ID: <20150612142328.GF12174@arm.com> References: <1434118810-28219-1-git-send-email-b.reynal@virtualopensystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1434118810-28219-1-git-send-email-b.reynal-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@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 To: Baptiste Reynal Cc: "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "tech-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org" , "qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org" List-Id: iommu@lists.linux-foundation.org On Fri, Jun 12, 2015 at 03:20:04PM +0100, Baptiste Reynal wrote: > The ARM SMMU has support for 2-stages address translations, allowing a virtual > address to be translated at two levels: > - Stage 1 translates a virtual address (VA) into an intermediate physical > address (IPA) > - Stage 2 translates an IPA into a physical address (PA) > > Will Deacon introduced a virtual SMMU interface for KVM, which gives a virtual > machine the possibility to use an IOMMU with native drivers. While the VM will > program the first stage of translation (stage 1), the interface will program > the second (stage 2) on the physical SMMU. Please note that I have no plans to merge the kernel-side of this at the moment. It was merely an exploratory tool to see what a non-PV vSMMU implementation might look like and certainly not intended to be used in anger. Will