x86: First fixmap entry (0) is invalid.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h
index 4917336a715de34d7d3c3f249cbabeb2764a5700..07afbc254dfcba3f37e24a086d79fbfbc3bbc213 100644 (file)
--- a/xen/include/asm-x86/fixmap.h
+++ b/xen/include/asm-x86/fixmap.h
@@ -29,6 +29,7 @@
  * from the end of virtual memory backwards.
  */
 enum fixed_addresses {
+    FIX_RESERVED, /* Index 0 is reserved since fix_to_virt(0) > FIXADDR_TOP. */
 #ifdef __i386__
     FIX_PAE_HIGHMEM_0,
     FIX_PAE_HIGHMEM_END = FIX_PAE_HIGHMEM_0 + NR_CPUS-1,