From: ddugger@redhat.com <ddugger@redhat.com>
Date: Mon, 23 Mar 2009 10:23:12 -0600
Subject: [xen] x86: fix EPT for VT-d
Message-id: 200903231623.n2NGNCnZ022078@sobek.n0ano.com
O-Subject: [RHEL5.4 PATCH 9/21 V2] Fix EPT for VT-d
Bugzilla: 484227
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Chris Lalancette <clalance@redhat.com>

hardcode UC for mmio of assigned devices in ept table similarly to what
was done for p2m.

Upstream Status: Accepted (in a different form)

This patch differs from upstram since it is a simplification, upstream
uses a more invasive change to allow finer grain control through the
MTRR/PAT registers, more flexible but not needed for the current use
cases for VTd.

BZ: 484227

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Gerd Hoffman <kraxel@redhat.com>
Signed-off-by: Don Dugger <donald.d.dugger@intel.com>

diff --git a/arch/x86/mm/p2m-ept.c b/arch/x86/mm/p2m-ept.c
index ac9df26..e5420f5 100644
--- a/arch/x86/mm/p2m-ept.c
+++ b/arch/x86/mm/p2m-ept.c
@@ -46,7 +46,7 @@ compat_ept_set_entry(struct domain *d, unsigned long gfn,
   mfn_t mfn, int order, u32 l1e_flags)
 {
     p2m_type_t t = ept_flags_to_p2m_type(l1e_flags);
-    if ( t == p2m_ram_rw &&
+    if ( t == p2m_ram_rw && mfn_x(mfn) != INVALID_MFN &&
          iomem_access_permitted(d, mfn_x(mfn), mfn_x(mfn)) )
         t = p2m_mmio_direct;
 
@@ -260,7 +260,10 @@ ept_set_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
         for ( i = 0; i < 512; i++ )
         {
             split_ept_entry = split_table + i;
-            split_ept_entry->emt = EPT_DEFAULT_MT;
+            if ( p2mt == p2m_mmio_direct )
+                split_ept_entry->emt = 0x8;
+            else
+                split_ept_entry->emt = EPT_DEFAULT_MT;
             split_ept_entry->sp_avail =  0;
 
             split_ept_entry->mfn = split_mfn+i;
@@ -275,7 +278,10 @@ ept_set_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
 
         /* Set the destinated 4k page as normal */
         split_ept_entry = split_table + offset;
-        split_ept_entry->emt = EPT_DEFAULT_MT;
+        if ( p2mt == p2m_mmio_direct )
+            split_ept_entry->emt = 0x8;
+        else
+            split_ept_entry->emt = EPT_DEFAULT_MT;
         split_ept_entry->mfn = mfn_x(mfn);
         split_ept_entry->avail1 = p2mt;
         ept_p2m_type_to_flags(split_ept_entry, p2mt);