diff -r f8187a343ad2 xen/arch/ia64/xen/mm.c
--- a/xen/arch/ia64/xen/mm.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/arch/ia64/xen/mm.c	Mon Feb 23 14:35:20 2009 -0500
@@ -3236,8 +3236,13 @@ int get_page_type(struct page_info *page
     return 1;
 }
 
-int page_is_conventional_ram(unsigned long mfn)
+int page_is_ram_type(unsigned long mfn, unsigned long type)
 {
+    /**
+     * N.B. This function could be enhanced to return what is more in line with the e820
+     * semantics for usable and reservered RAM. Since it is only used once in vga.c in 
+     * the IA64 case it is ok to ignore the type parameter.
+     */
     return (efi_mem_type(pfn_to_paddr(mfn)) == EFI_CONVENTIONAL_MEMORY);
 }
 
diff -r f8187a343ad2 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/arch/x86/mm.c	Mon Feb 23 14:35:20 2009 -0500
@@ -279,15 +279,30 @@ void __init arch_init_memory(void)
     subarch_init_memory();
 }
 
-int page_is_conventional_ram(unsigned long mfn)
+int page_is_ram_type(unsigned long mfn, unsigned long mem_type)
 {
     uint64_t maddr = pfn_to_paddr(mfn);
     int i;
 
     for ( i = 0; i < e820.nr_map; i++ )
     {
-        if ( (e820.map[i].type == E820_RAM) &&
-             (e820.map[i].addr <= maddr) &&
+        switch (e820.map[i].type)
+        {
+        case E820_RAM:
+            if (mem_type & RAM_TYPE_CONVENTIONAL)
+                break;
+            continue;
+        case E820_RESERVED:
+            if (mem_type & RAM_TYPE_RESERVED)
+                break;
+            continue;
+        default:
+            /* unknown */
+            continue;
+        }
+        
+        /* test the range */
+        if ( (e820.map[i].addr <= maddr) &&
              ((e820.map[i].addr + e820.map[i].size) >= (maddr + PAGE_SIZE)) )
             return 1;
     }
diff -r f8187a343ad2 xen/arch/x86/setup.c
--- a/xen/arch/x86/setup.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/arch/x86/setup.c	Mon Feb 23 14:35:20 2009 -0500
@@ -986,6 +986,9 @@ void __init __start_xen(unsigned long mb
     if ( opt_watchdog ) 
         watchdog_enable();
 
+    if ( !tboot_protect_mem_regions() )
+        panic("Could not protect TXT memory regions\n");
+
     /* Create initial domain 0. */
     dom0 = domain_create(0, 0, DOM0_SSIDREF);
     if ( (dom0 == NULL) || (alloc_vcpu(dom0, 0, 0) == NULL) )
@@ -1036,9 +1039,6 @@ void __init __start_xen(unsigned long mb
 
     if ( xen_cpuidle )
         xen_processor_pmbits |= XEN_PROCESSOR_PM_CX;
-
-    if ( !tboot_protect_mem_regions() )
-        panic("Could not protect TXT memory regions\n");
 
     /*
      * We're going to setup domain0 using the module(s) that we stashed safely
diff -r f8187a343ad2 xen/drivers/passthrough/vtd/dmar.c
--- a/xen/drivers/passthrough/vtd/dmar.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/drivers/passthrough/vtd/dmar.c	Mon Feb 23 14:35:20 2009 -0500
@@ -377,6 +377,19 @@ acpi_parse_one_rmrr(struct acpi_dmar_ent
         return -EFAULT;
     }
 
+#ifdef CONFIG_X86
+    /* This check is here simply to detect when RMRR values are not properly represented in the 
+       system memory map and inform the user */
+    if ( (!page_is_ram_type(paddr_to_pfn(rmrr->base_address), RAM_TYPE_RESERVED))||
+         (!page_is_ram_type(paddr_to_pfn(rmrr->end_address) - 1, RAM_TYPE_RESERVED)) )
+    {
+        dprintk(XENLOG_WARNING VTDPREFIX,
+                "RMRR address range not in reserved memory base = %"PRIx64" end = %"PRIx64"; " \
+                "iommu_include_reserved=1 parameter may be needed.\n",
+                rmrr->base_address, rmrr->end_address);
+    }
+#endif
+
     rmrru = xmalloc(struct acpi_rmrr_unit);
     if ( !rmrru )
         return -ENOMEM;
diff -r f8187a343ad2 xen/drivers/passthrough/vtd/iommu.c
--- a/xen/drivers/passthrough/vtd/iommu.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/drivers/passthrough/vtd/iommu.c	Mon Feb 23 14:35:20 2009 -0500
@@ -992,8 +992,6 @@ static int intel_iommu_domain_init(struc
 
     if ( d->domain_id == 0 )
     {
-        extern int xen_in_range(paddr_t start, paddr_t end);
-
         /* Set up 1:1 page table for dom0 */
         iommu_set_dom0_mapping(d);
 
diff -r f8187a343ad2 xen/drivers/passthrough/vtd/x86/vtd.c
--- a/xen/drivers/passthrough/vtd/x86/vtd.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/drivers/passthrough/vtd/x86/vtd.c	Mon Feb 23 14:35:20 2009 -0500
@@ -26,6 +26,10 @@
 #include "../iommu.h"
 #include "../dmar.h"
 #include "../vtd.h"
+
+/* iommu_include_reserved: include reserved memory ranges in dom0 1-1 iommu mappings if set */
+static int iommu_include_reserved = 0;
+boolean_param("iommu_include_reserved", iommu_include_reserved);
 
 void *map_vtd_domain_page(u64 maddr)
 {
@@ -147,15 +151,22 @@ void iommu_set_dom0_mapping(struct domai
 void iommu_set_dom0_mapping(struct domain *d)
 {
     u64 i, j, tmp;
+    u32 mem_type;
     extern int xen_in_range(paddr_t start, paddr_t end);
 
     BUG_ON(d->domain_id != 0);
 
+    /* input param overrides default memory mapping */
+    mem_type = RAM_TYPE_CONVENTIONAL;
+    if (iommu_include_reserved)
+        mem_type |= RAM_TYPE_RESERVED;
+
     for ( i = 0; i < max_page; i++ )
     {
-        /* Set up 1:1 mapping for dom0 for all RAM except Xen bits. */
-        if ( !page_is_conventional_ram(i) ||
-             xen_in_range(i << PAGE_SHIFT, (i + 1) << PAGE_SHIFT) )
+        /* Set up 1:1 mapping for dom0 for all RAM except Xen bits and reserved, unusable, etc. */
+        /* Modified to include reserved memory regions for some broken BIOS' */
+        if ( !page_is_ram_type(i, mem_type) ||
+              xen_in_range(i << PAGE_SHIFT, (i + 1) << PAGE_SHIFT) )
             continue;
 
         tmp = 1 << (PAGE_SHIFT - PAGE_SHIFT_4K);
diff -r f8187a343ad2 xen/drivers/video/vga.c
--- a/xen/drivers/video/vga.c	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/drivers/video/vga.c	Mon Feb 23 14:35:20 2009 -0500
@@ -79,7 +79,7 @@ void __init vga_init(void)
     switch ( vga_console_info.video_type )
     {
     case XEN_VGATYPE_TEXT_MODE_3:
-        if ( page_is_conventional_ram(paddr_to_pfn(0xB8000)) ||
+        if ( page_is_ram_type(paddr_to_pfn(0xB8000), RAM_TYPE_CONVENTIONAL) ||
              ((video = ioremap(0xB8000, 0x8000)) == NULL) )
             return;
         outw(0x200a, 0x3d4); /* disable cursor */
diff -r f8187a343ad2 xen/include/xen/mm.h
--- a/xen/include/xen/mm.h	Fri Feb 20 17:02:36 2009 +0000
+++ b/xen/include/xen/mm.h	Mon Feb 23 14:35:20 2009 -0500
@@ -273,8 +273,10 @@ unsigned long avail_scrub_pages(void);
 
 int guest_remove_page(struct domain *d, unsigned long gmfn);
 
-/* Returns TRUE if the whole page at @mfn is ordinary RAM. */
-int page_is_conventional_ram(unsigned long mfn);
+#define RAM_TYPE_CONVENTIONAL 0x00000001
+#define RAM_TYPE_RESERVED     0x00000002
+/* Returns TRUE if the whole page at @mfn is of the requested RAM type(s) above. */
+int page_is_ram_type(unsigned long mfn, unsigned long mem_type);
 
 extern unsigned long *alloc_bitmap;	/* for vmcoreinfo */