Silenty ignore calls to xen_create_contiguous_region() when running

in auto_translated_physmap mode. A new comment in that function explains
why this is an okay thing to do.

This avoids an unnecessary crash in Xen's skbuff_ctor.

Signed-off-by: Michael Vrable <mvrable@cs.ucsd.edu>
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c b/linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c
index 2413c5cc4f3368ca49c161305a4a742bb6ddbe05..cfc359e4916c06df0b368bad0320d558e19e5223 100644 (file)
--- a/linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c
+++ b/linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c
@@ -324,10 +324,13 @@ int xen_create_contiguous_region(
                .domid        = DOMID_SELF
        };
 
-       if (xen_feature(XENFEAT_auto_translated_physmap)) {
-               BUG_ON(order >= 1);
+       /*
+        * Currently an auto-translated guest will not perform I/O, nor will
+        * it require PAE page directories below 4GB. Therefore any calls to
+        * this function are redundant and can be ignored.
+        */
+       if (xen_feature(XENFEAT_auto_translated_physmap))
                return 0;
-       }
 
        scrub_pages(vstart, 1 << order);