bitkeeper revision 1.1382 (426d084fj_L9HqLwTZs1okz5LbnXcg)

Fix writable pagetables for uniproc domains such that we don't use the
emulation path every time.
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index e4f989ad5e65c63d98821ad5bbe929f6a8f87f17..fdf2d8af713e25cd96a4d6cb60939558d4c66dfb 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2802,7 +2802,11 @@ int ptwr_do_page_fault(struct domain *d, unsigned long addr)
      * update to ensure we make progress.
      */
     if ( d->arch.ptwr[which].prev_nr_updates == 0 )
+    {
+        /* Ensure that we don't get stuck in an emulation-only rut. */
+        d->arch.ptwr[which].prev_nr_updates = 1;
         goto emulate;
+    }
 
     d->arch.ptwr[which].l1va   = addr | 1;
     d->arch.ptwr[which].l2_idx = l2_idx;