[XEN][SHADOW] Use slow method for early-unshadow

The "fast" method fails a significant portion of the time.
unshadow will still use the "fast" method, but will fall
back to a brute-force method if it fails.

Signed-off-by: George Dunlap <gdunlap@xensource.com>

diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index e691b7fa8c55c5def92fd5e328e50588b75b7a07..581ab45196aacde65504b19ce9f6fc42638d515c 100644 (file)
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -2522,7 +2522,7 @@ static inline void check_for_early_unshadow(struct vcpu *v, mfn_t gmfn)
         if ( !(flags & (SHF_L2_32|SHF_L2_PAE|SHF_L2H_PAE|SHF_L4_64)) )
         {
             perfc_incrc(shadow_early_unshadow);
-            sh_remove_shadows(v, gmfn, 1, 0 /* Fast, can fail to unshadow */ );
+            sh_remove_shadows(v, gmfn, 0, 0 /* Slow, can fail to unshadow */ );
         } 
     }
     v->arch.paging.shadow.last_emulated_mfn = mfn_x(gmfn);