EPT/VT-d: Enhance MTRR/PAT virtualization when EPT/VT-d both enabled

Set effective memory type for EPT according to the VT-d snoop control
capability, and also includes some cleanups for EPT & VT-d both enabled.

Signed-off-by: Edwin Zhai <Edwin.Zhai@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c
index d6692d2b3d..6f64062cf9 100644
--- a/xen/arch/x86/hvm/mtrr.c
+++ b/xen/arch/x86/hvm/mtrr.c
@@ -702,12 +702,15 @@ HVM_REGISTER_SAVE_RESTORE(MTRR, hvm_save_mtrr_msr, hvm_load_mtrr_msr,
                           1, HVMSR_PER_VCPU);
 
 uint8_t epte_get_entry_emt(
-    struct domain *d, unsigned long gfn, unsigned long mfn)
+    struct domain *d, unsigned long gfn, 
+    unsigned long mfn, uint8_t *igmt, int direct_mmio)
 {
     uint8_t gmtrr_mtype, hmtrr_mtype;
     uint32_t type;
     struct vcpu *v = current;
 
+    *igmt = 0;
+
     if ( (current->domain != d) && ((v = d->vcpu[0]) == NULL) )
         return MTRR_TYPE_WRBACK;
 
@@ -723,6 +726,21 @@ uint8_t epte_get_entry_emt(
     if ( hvm_get_mem_pinned_cacheattr(d, gfn, &type) )
         return type;
 
+    if ( !iommu_enabled )
+    {
+        *igmt = 1;
+        return MTRR_TYPE_WRBACK;
+    }
+
+    if ( direct_mmio )
+        return MTRR_TYPE_UNCACHABLE;
+
+    if ( iommu_snoop )
+    {
+        *igmt = 1;
+        return MTRR_TYPE_WRBACK;
+    }
+
     gmtrr_mtype = get_mtrr_type(&v->arch.hvm_vcpu.mtrr, (gfn << PAGE_SHIFT));
     hmtrr_mtype = get_mtrr_type(&mtrr_state, (mfn << PAGE_SHIFT));
     return ((gmtrr_mtype <= hmtrr_mtype) ? gmtrr_mtype : hmtrr_mtype);