From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: [RFC PATCHv2 1/3] iommu: introduce domain attribute for nesting IOMMUs Date: Wed, 9 Jul 2014 19:28:44 +0100 Message-ID: <1404930526-32119-2-git-send-email-will.deacon@arm.com> References: <1404930526-32119-1-git-send-email-will.deacon@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1404930526-32119-1-git-send-email-will.deacon-5wv7dgnIgG8@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: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: Will Deacon List-Id: iommu@lists.linux-foundation.org Some IOMMUs, such as the ARM SMMU, support two stages of translation. The idea behind such a scheme is to allow a guest operating system to use the IOMMU for DMA mappings in the first stage of translation, with the hypervisor then installing mappings in the second stage to provide isolation of the DMA to the physical range assigned to that virtual machine. In order to allow IOMMU domains to be used for second-stage translation, this patch adds a new iommu_attr (IOMMU_ATTR_NESTING) for setting second-stage domains prior to device attach. The attribute can also be queried to see if a domain is actually making use of nesting. Cc: Joerg Roedel Cc: Alex Williamson Signed-off-by: Will Deacon --- include/linux/iommu.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index b96a5b2136e4..0550286df49b 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -80,6 +80,7 @@ enum iommu_attr { DOMAIN_ATTR_FSL_PAMU_STASH, DOMAIN_ATTR_FSL_PAMU_ENABLE, DOMAIN_ATTR_FSL_PAMUV1, + DOMAIN_ATTR_NESTING, /* two stages of translation */ DOMAIN_ATTR_MAX, }; -- 2.0.0