[Xen-devel] [v2][PATCH 1/1] xen:vtd: missing RMRR mapping while share EPT

[Tiejun Chen <tiejun.chen@xxxxxxxxx>]

intel_iommu_map_page() does nothing if VT-d shares EPT page table.
So rmrr_identity_mapping() never create RMRR mapping but in some
cases like some GFX drivers it still need to access RMRR.

Here we will create those RMRR mappings even in shared EPT case.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
---
 xen/drivers/passthrough/vtd/iommu.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

v2:

* Fix coding style.
* Still need to abide intel_iommu_map_page(), so we should do nothing
  if dom0 and iommu supports pass thru.

diff --git a/xen/drivers/passthrough/vtd/iommu.c 
b/xen/drivers/passthrough/vtd/iommu.c
index 042b882..aca79db 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -41,6 +41,7 @@
 #include "extern.h"
 #include "vtd.h"
 #include "../ats.h"
+#include "../../../arch/x86/mm/mm-locks.h"
 
 struct mapped_rmrr {
     struct list_head list;
@@ -1842,6 +1843,7 @@ static int rmrr_identity_mapping(struct domain *d,
     unsigned long base_pfn, end_pfn;
     struct mapped_rmrr *mrmrr;
     struct hvm_iommu *hd = domain_hvm_iommu(d);
+    struct p2m_domain *p2m = p2m_get_hostp2m(d);
 
     ASSERT(spin_is_locked(&pcidevs_lock));
     ASSERT(rmrr->base_address < rmrr->end_address);
@@ -1867,8 +1869,20 @@ static int rmrr_identity_mapping(struct domain *d,
 
     while ( base_pfn < end_pfn )
     {
-        if ( intel_iommu_map_page(d, base_pfn, base_pfn,
-                                  IOMMUF_readable|IOMMUF_writable) )
+        if ( iommu_use_hap_pt(d) && (!iommu_passthrough ||
+                                     !is_hardware_domain(d)) )
+        {
+            p2m_lock(p2m);
+            if ( p2m_set_entry(p2m, base_pfn, _mfn(base_pfn), PAGE_ORDER_4K,
+                               p2m_mmio_direct, p2m_access_rw) )
+            {
+                p2m_unlock(p2m);
+                return -1;
+            }
+            p2m_unlock(p2m);
+        }
+        else if ( intel_iommu_map_page(d, base_pfn, base_pfn,
+                                       IOMMUF_readable|IOMMUF_writable) )
             return -1;
         base_pfn++;
     }
-- 
1.9.1


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