[Xen-changelog] [xen-unstable] x86 shadow: Cleanup for early-unshadow code.

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1202133077 0
# Node ID 7e6a705e8ec521f538519ca62ca5b7b59b45c36f
# Parent  4e9b5427f2d83c3cccd18c9262b6126fc61f1191
x86 shadow: Cleanup for early-unshadow code.

The unhooking of toplevel shadow entries has been removed; the rest of
the early-unshadow code needs to reflect that.

Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxx>
---
 xen/arch/x86/mm/shadow/multi.c   |   16 +++-------------
 xen/arch/x86/mm/shadow/private.h |    3 ---
 2 files changed, 3 insertions(+), 16 deletions(-)

diff -r 4e9b5427f2d8 -r 7e6a705e8ec5 xen/arch/x86/mm/shadow/multi.c
--- a/xen/arch/x86/mm/shadow/multi.c    Mon Feb 04 13:44:29 2008 +0000
+++ b/xen/arch/x86/mm/shadow/multi.c    Mon Feb 04 13:51:17 2008 +0000
@@ -2588,19 +2588,15 @@ sh_map_and_validate_gl1e(struct vcpu *v,
  * easier. */
 
 /* Look to see if this is the second emulated write in a row to this
- * page, and unshadow/unhook if it is */
+ * page, and unshadow if it is */
 static inline void check_for_early_unshadow(struct vcpu *v, mfn_t gmfn)
 {
 #if SHADOW_OPTIMIZATIONS & SHOPT_EARLY_UNSHADOW
     if ( v->arch.paging.shadow.last_emulated_mfn == mfn_x(gmfn) &&
          sh_mfn_is_a_page_table(gmfn) )
     {
-        u32 flags = mfn_to_page(gmfn)->shadow_flags;
-        if ( !(flags & (SHF_L2_32|SHF_L2_PAE|SHF_L2H_PAE|SHF_L4_64)) )
-        {
-            perfc_incr(shadow_early_unshadow);
-            sh_remove_shadows(v, gmfn, 1, 0 /* Fast, can fail to unshadow */ );
-        } 
+        perfc_incr(shadow_early_unshadow);
+        sh_remove_shadows(v, gmfn, 1, 0 /* Fast, can fail to unshadow */ );
     }
     v->arch.paging.shadow.last_emulated_mfn = mfn_x(gmfn);
 #endif
@@ -3487,12 +3483,6 @@ sh_set_toplevel_shadow(struct vcpu *v,
     }
     ASSERT(mfn_valid(smfn));
     
-#if SHADOW_OPTIMIZATIONS & SHOPT_EARLY_UNSHADOW
-    /* Once again OK to unhook entries from this table if we see fork/exit */
-    ASSERT(sh_mfn_is_a_page_table(gmfn));
-    mfn_to_page(gmfn)->shadow_flags &= ~SHF_unhooked_mappings;
-#endif
-
     /* Pin the shadow and put it (back) on the list of pinned shadows */
     if ( sh_pin(v, smfn) == 0 )
     {
diff -r 4e9b5427f2d8 -r 7e6a705e8ec5 xen/arch/x86/mm/shadow/private.h
--- a/xen/arch/x86/mm/shadow/private.h  Mon Feb 04 13:44:29 2008 +0000
+++ b/xen/arch/x86/mm/shadow/private.h  Mon Feb 04 13:51:17 2008 +0000
@@ -334,9 +334,6 @@ static inline int sh_type_is_pinnable(st
 #define SHF_PAE (SHF_L1_PAE|SHF_FL1_PAE|SHF_L2_PAE|SHF_L2H_PAE)
 #define SHF_64  (SHF_L1_64|SHF_FL1_64|SHF_L2_64|SHF_L2H_64|SHF_L3_64|SHF_L4_64)
 
-/* Used for hysteresis when automatically unhooking mappings on fork/exit */
-#define SHF_unhooked_mappings (1u<<31)
-
 
 /******************************************************************************
  * Various function declarations 

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