Index: OvmfPkg/Library/AcpiTimerLib/AcpiTimerLib.c
===================================================================
--- OvmfPkg/Library/AcpiTimerLib/AcpiTimerLib.c	(revision 8827)
+++ OvmfPkg/Library/AcpiTimerLib/AcpiTimerLib.c	(working copy)
@@ -17,10 +17,23 @@
 #include <Library/BaseLib.h>
 #include <Library/IoLib.h>
 #include <Library/PciLib.h>
+#include <Library/DebugLib.h>
 
 #define ACPI_TIMER_FREQUENCY   3579545
 #define ACPI_TIMER_COUNT_SIZE  0x01000000
 
+struct DeviceProbe
+{
+    UINT8 Device;
+    UINT16 VendorID;
+    UINT16 DeviceID;
+};
+
+struct DeviceProbe DeviceProber[] =
+{
+    {1, 0xabad, 0xbabe }, /*qemu, todo fill right values */
+    {7, 0x8086, 0x7113 }, /*vbox*/
+};
 /**
   The constructor function enables ACPI IO space.
 
@@ -36,17 +49,30 @@
   VOID
   )
 {
-  UINT8 Device;
+  UINT8 Device = (UINT8)~0;
+  UINT16 DeviceID;
+  UINT16 VendorID;
+  UINTN i;
+  for (i = 0; i < 2; ++i)
+  {
+    VendorID = PciRead16(PCI_LIB_ADDRESS(0, DeviceProber[i].Device, 0, 0));
+    DeviceID = PciRead16(PCI_LIB_ADDRESS(0, DeviceProber[i].Device, 0, 2));
+    DEBUG((DEBUG_INFO, "TM(%d)(VendorID:%x, DeviceID(%x))\n", DeviceProber[i].Device, VendorID, DeviceID));
+    if (VendorID == DeviceProber[i].VendorID 
+        && DeviceID == DeviceProber[i].DeviceID)
+    {
+        Device = DeviceProber[i].Device;
+        break;
+    }    
+  }
+  ASSERT(Device != (UINT8)~0);
 
-  Device = 1;
-  // Device = 7;
-
   //
-  // ACPI Timer enable is in Bus 0, Device ?, Function 3
+  // ACPI Timer enable is in Bus 0, Device ?, Function 0
   //
-  PciOr8         (PCI_LIB_ADDRESS (0,Device,3,0x04), 0x01);
-  PciAndThenOr32 (PCI_LIB_ADDRESS (0,Device,3,0x40), (UINT32) ~0xfc0, 0x400);
-  PciOr8         (PCI_LIB_ADDRESS (0,Device,3,0x80), 0x01);  return RETURN_SUCCESS;
+  PciOr8         (PCI_LIB_ADDRESS (0,Device,0,0x04), 0x01);
+  PciAndThenOr32 (PCI_LIB_ADDRESS (0,Device,0,0x40), (UINT32) ~0xfc0, 0x400);
+  PciOr8         (PCI_LIB_ADDRESS (0,Device,0,0x80), 0x01);  return RETURN_SUCCESS;
 }
 
 /**