diff -Nur nv/conftest.sh nv-patched/conftest.sh
--- nv/conftest.sh	2007-06-13 20:18:39.000000000 -0400
+++ nv-patched/conftest.sh	2007-07-25 09:04:48.000000000 -0400
@@ -896,65 +896,6 @@
         fi
     ;;
 
-    xen_sanity_check)
-        #
-        # Check if the target kernel is a Xen kernel. If so, then exit, since
-        # the driver doesn't currently work with Xen.
-        #
-        RET=1
-        VERBOSE=$6
-        FILE="linux/autoconf.h"
-
-        if [ -n "$IGNORE_XEN_PRESENCE" ]; then
-            exit 0
-        fi
-
-        if [ -f $HEADERS/$FILE -o -f $OUTPUT/include/$FILE ]; then
-            #
-            # We are looking at a configured source tree; verify
-            # that it's not a Xen kernel.
-            #
-            echo "#include <linux/autoconf.h>
-            #ifdef CONFIG_XEN
-            #error CONFIG_XEN defined!!
-            #endif
-            " > conftest$$.c
-
-            $CC $CFLAGS -c conftest$$.c > /dev/null 2>&1
-            rm -f conftest$$.c
-
-            if [ -f conftest$$.o ]; then
-                rm -f conftest$$.o
-                RET=0
-            fi
-        else
-            CONFIG=$HEADERS/../.config
-            if [ -f $CONFIG ]; then
-                if [ -z "$(grep "^CONFIG_XEN=y" $CONFIG)" ]; then
-                    RET=0
-                fi
-            fi
-        fi
-
-        if [ "$RET" != "0" ]; then
-            echo "The kernel you are installing for is a Xen kernel!";
-            echo "";
-            echo "The NVIDIA driver does not currently work on Xen kernels. If ";
-            echo "you are using a stock distribution kernel, please install ";
-            echo "a variant of this kernel without Xen support; if this is a ";
-            echo "custom kernel, please install a standard Linux kernel.  Then ";
-            echo "try installing the NVIDIA kernel module again.";
-            echo "";
-            if [ "$VERBOSE" = "full_output" ]; then
-                echo "*** Failed Xen sanity check. Bailing out! ***";
-                echo "";
-            fi
-            exit 1
-        else
-            exit 0
-        fi
-    ;;
-
     acpi_device_ops_match)
         #
         # Determine if the acpi_device_ops data structure has
diff -Nur nv/nv.c nv-patched/nv.c
--- nv/nv.c	2007-06-13 20:18:38.000000000 -0400
+++ nv-patched/nv.c	2007-07-25 09:04:48.000000000 -0400
@@ -42,10 +42,13 @@
 
 int nv_pat_enabled = 0;
 
-#if !defined(NV_BUILD_NV_PAT_SUPPORT)
+#if defined(CONFIG_XEN) || defined(CONFIG_PREEMPT_RT)
 static int nv_disable_pat = 1;
 #else
 static int nv_disable_pat = 0;
+#endif
+
+#if !defined(CONFIG_XEN)
 NV_MODULE_PARAMETER(nv_disable_pat);
 #endif
 
diff -Nur nv/nv-linux.h nv-patched/nv-linux.h
--- nv/nv-linux.h	2007-06-13 20:18:38.000000000 -0400
+++ nv-patched/nv-linux.h	2007-07-25 09:04:48.000000000 -0400
@@ -261,7 +261,7 @@
  * tiny, and the kernel panics when it is exhausted. try to warn the user that
  * they need to boost the size of their pool.
  */
-#if defined(CONFIG_SWIOTLB) && !defined(GFP_DMA32)
+#if defined(CONFIG_SWIOTLB) && !defined(GFP_DMA32) && !defined(CONFIG_XEN)
 #define NV_SWIOTLB 1
 #endif
 
@@ -821,7 +821,10 @@
 #define NV_VM_INSERT_PAGE(vma, addr, page) \
     vm_insert_page(vma, addr, page)
 #endif
-#if defined(NV_REMAP_PFN_RANGE_PRESENT)
+#if defined(CONFIG_XEN)
+#define NV_REMAP_PAGE_RANGE(from, offset, x...) \
+ io_remap_pfn_range(vma, from, ((offset) >> PAGE_SHIFT), x)
+#elif defined(NV_REMAP_PFN_RANGE_PRESENT)
 #define NV_REMAP_PAGE_RANGE(from, offset, x...) \
     remap_pfn_range(vma, from, ((offset) >> PAGE_SHIFT), x)
 #elif defined(NV_REMAP_PAGE_RANGE_5_PRESENT)
@@ -833,6 +836,7 @@
 #define NV_REMAP_PAGE_RANGE(x...) remap_page_range(x)
 #endif
 #if !defined(CONFIG_XEN)
+#define phys_to_machine(x) x
 #define NV_IO_REMAP_PAGE_RANGE(from, offset, x...) \
     NV_REMAP_PAGE_RANGE(from, offset, x)
 #else
diff -Nur nv/nv-vm.c nv-patched/nv-vm.c
--- nv/nv-vm.c	2007-06-13 20:18:38.000000000 -0400
+++ nv-patched/nv-vm.c	2007-07-25 09:04:48.000000000 -0400
@@ -352,6 +352,10 @@
 
 static void nv_flush_caches(void)
 {
+#if defined(CONFIG_PREEMPT_RT)
+ if(!nv_pat_enabled) return;
+#endif
+
 #if defined(KERNEL_2_4)
     // for 2.4 kernels, just automatically flush the caches and invalidate tlbs
     nv_execute_on_all_cpus(cache_flush, NULL);
diff -Nur nv/os-agp.c nv-patched/os-agp.c
--- nv/os-agp.c	2007-06-13 20:18:38.000000000 -0400
+++ nv-patched/os-agp.c	2007-07-25 09:04:48.000000000 -0400
@@ -295,7 +295,7 @@
 
          page_ptr->phys_addr = (ptr->memory[i] & PAGE_MASK);
          page_ptr->virt_addr = (unsigned long) __va(page_ptr->phys_addr);
-         page_ptr->dma_addr  = page_ptr->phys_addr;
+         page_ptr->dma_addr = phys_to_machine(page_ptr->phys_addr);
     }
 
     return RM_OK;
diff -Nur nv/os-interface.c nv-patched/os-interface.c
--- nv/os-interface.c	2007-06-13 20:18:38.000000000 -0400
+++ nv-patched/os-interface.c	2007-07-25 09:04:48.000000000 -0400
@@ -552,6 +552,7 @@
     MicroSeconds = MilliSeconds * 1000;
     tm_end.tv_usec = MicroSeconds;
     tm_end.tv_sec = 0;
+#if !defined(CONFIG_XEN)
     NV_TIMERADD(&tm_aux, &tm_end, &tm_end);
 
     /* do we have a full jiffie to wait? */
@@ -599,7 +600,7 @@
                 MicroSeconds = 0;
         } while ((jiffies = NV_USECS_TO_JIFFIES(MicroSeconds)) != 0);
     }
-
+#endif
     if (MicroSeconds > 1000)
     {
         mdelay_safe_msec = MicroSeconds / 1000;