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authorWill Deacon <will.deacon@arm.com>2014-09-29 10:05:06 -0600
committerAlex Williamson <alex.williamson@redhat.com>2014-09-29 10:05:06 -0600
commitc02607aad2f9ed478eb288bcec1c00cd9df38b3c (patch)
tree71f336edfc63d0dfeae330d03bccd45f40f5b0bd
parentfe82dcec644244676d55a1384c958d5f67979adb (diff)
downloadop-kernel-dev-c02607aad2f9ed478eb288bcec1c00cd9df38b3c.zip
op-kernel-dev-c02607aad2f9ed478eb288bcec1c00cd9df38b3c.tar.gz
iommu: introduce domain attribute for nesting IOMMUs
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. Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
-rw-r--r--include/linux/iommu.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 20f9a52..7b02bcc 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,
};
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