[Xen-devel] [RFC][PATCH 06/13] xen:vtd: create RMRR mapping

[Tiejun Chen <tiejun.chen@xxxxxxxxx>]

RMRR reserved regions must be setup in the pfn space with an identity
mapping to reported mfn. However existing code has problem to setup
correct mapping when VT-d shares EPT page table, so lead to problem
when assigning devices (e.g GPU) with RMRR reported. This patch
aims to setup identity mapping in p2m layer, regardless of whether EPT
is shared or not.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
---
 xen/drivers/passthrough/vtd/iommu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/xen/drivers/passthrough/vtd/iommu.c 
b/xen/drivers/passthrough/vtd/iommu.c
index 4e789d1..f8fc6c3 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1847,6 +1847,12 @@ static int rmrr_identity_mapping(struct domain *d, 
bool_t map,
 
         if ( err )
             return err;
+
+        if ( !is_hardware_domain(d) )
+        {
+            if ( (err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw)) )
+                return err;
+        }
         base_pfn++;
     }
 
-- 
1.9.1


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