From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: [PATCH v5 1/2] iommu: introduce domain attribute for nesting IOMMUs Date: Thu, 25 Sep 2014 18:45:00 +0100 Message-ID: <1411667101-26197-2-git-send-email-will.deacon@arm.com> References: <1411667101-26197-1-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: <1411667101-26197-1-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: Alex Williamson Acked-by: Joerg Roedel 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 20f9a527922a..7b02bcc85b9e 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, }; -- 2.1.0