diff -r c4f3f719d997 xen/arch/x86/x86_64/entry.S
--- a/xen/arch/x86/x86_64/entry.S	Sat Sep 23 13:54:58 2006
+++ b/xen/arch/x86/x86_64/entry.S	Sun Oct  8 01:20:36 2006
@@ -339,6 +339,21 @@
         jnz   test_all_events
         jmp   restore_all_xen
 
+.data
+ENTRY(last_exception_type)
+  .int 0
+
+ENTRY(last_exception_error_code)
+  .int 0
+
+ENTRY(last_exception_fixup_rip)
+  .quad 0
+
+ENTRY(last_exception_fixup_cr2)
+  .quad 0
+
+.previous
+
         ALIGN
 /* No special register assumptions. */
 handle_exception:
@@ -347,7 +362,12 @@
         jz    exception_with_ints_disabled
         sti
         movq  %rsp,%rdi
+        movl  UREGS_error_code(%rsp),%eax
+        leaq  last_exception_error_code(%rip),%rdx
+        movl  %eax,(%rdx)
         movl  UREGS_entry_vector(%rsp),%eax
+        leaq  last_exception_type(%rip),%rdx
+        movl  %eax,(%rdx)
         leaq  exception_table(%rip),%rdx
         GET_CURRENT(%rbx)
         PERFC_INCR(PERFC_exceptions, %rax)
diff -r c4f3f719d997 xen/arch/x86/x86_64/traps.c
--- a/xen/arch/x86/x86_64/traps.c	Sat Sep 23 13:54:58 2006
+++ b/xen/arch/x86/x86_64/traps.c	Sun Oct  8 01:20:36 2006
@@ -36,6 +36,20 @@
            debug, print_tainted(taint_str));
 }
 
+#define TRAP_COUNT 20
+static char *trap_name[TRAP_COUNT] = { 
+    "divide error", "debug", "nmi", "bkpt",
+    "overflow", "bounds", "invalid opcode", "device not available",
+    "double fault",  "coprocessor segment", "invalid tss", "segment not found", 
+    "stack error", "general protection fault", "page fault", "spurious interrupt",
+    "coprocessor error", "alignment check", "machine check", "simd error"
+};
+
+extern unsigned int last_exception_type;
+extern unsigned int last_exception_error_code;
+extern unsigned long last_exception_fixup_rip;
+extern unsigned long last_exception_fixup_cr2;
+
 void show_registers(struct cpu_user_regs *regs)
 {
     struct cpu_user_regs fault_regs = *regs;
@@ -70,6 +84,10 @@
     }
 
     print_xen_info();
+    printk("Trap: %s (%d)\n", (last_exception_type < TRAP_COUNT) ? trap_name[last_exception_type] : "Unknown", last_exception_type);
+    printk("Error code %08x\n", last_exception_error_code);
+    printk("Last fixup: rip %p, cr2 %p\n", (void*)last_exception_fixup_rip, (void*)last_exception_fixup_cr2);
+    printk("Guest VCPU flags: %lu\n", current->arch.flags);
     printk("CPU:    %d\nRIP:    %04x:[<%016lx>]",
            smp_processor_id(), fault_regs.cs, fault_regs.rip);
     if ( !guest_mode(regs) )
diff -r c4f3f719d997 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c	Sat Sep 23 13:54:58 2006
+++ b/xen/arch/x86/traps.c	Sun Oct  8 01:20:36 2006
@@ -903,6 +958,9 @@
  *  Bit 3: Reserved bit violation
  *  Bit 4: Instruction fetch
  */
+extern unsigned long last_exception_fixup_rip;
+extern unsigned long last_exception_fixup_cr2;
+
 asmlinkage int do_page_fault(struct cpu_user_regs *regs)
 {
     unsigned long addr, fixup;
@@ -926,6 +984,8 @@
 
         if ( likely((fixup = search_exception_table(regs->eip)) != 0) )
         {
+            last_exception_fixup_rip = regs->eip;
+            last_exception_fixup_cr2 = addr;
             perfc_incrc(copy_user_faults);
             regs->eip = fixup;
             return 0;