[Qemu-devel] [RFC 04/20] memory: add IOMMU_ATTR_VFIO_NESTED IOMMU memory region attribute

[Eric Auger <eric.auger@redhat.com>]

We introduce a new IOMMU Memory Region attribute, IOMMU_ATTR_VFIO_NESTED
which tells whether the virtual IOMMU requires physical nested
stages for VFIO integration. Intel virtual IOMMU supports Caching
Mode and does not require 2 stages at physical level. However virtual
ARM SMMU does not implement such caching mode and requires to use
physical stage 1 for VFIO integration.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 include/exec/memory.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index eb4f2fb249..b6e59c139c 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -209,7 +209,8 @@ struct MemoryRegionOps {
 };
 
 enum IOMMUMemoryRegionAttr {
-    IOMMU_ATTR_SPAPR_TCE_FD
+    IOMMU_ATTR_SPAPR_TCE_FD,
+    IOMMU_ATTR_VFIO_NESTED,
 };
 
 /**
-- 
2.17.1