[XEN] Shadow mode no longer obtains page type references.

This allows the shadow destructor hook in free_page_type()
to work properly.

Also, move mark_dirty() back to alloc/free_page_type(). It
doesn't matter that this happens before the type count is
modified -- bitmap is extracted by the tools with the domain
paused, so these non-blocking paths are atomic from p.o.v of
the tools.

Signed-off-by: Keir Fraser <keir@xensource.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/xen/include/asm-x86/shadow.h b/xen/include/asm-x86/shadow.h
index b7c536477a..94a4ff11fd 100644
--- a/xen/include/asm-x86/shadow.h
+++ b/xen/include/asm-x86/shadow.h
@@ -325,24 +325,19 @@ void shadow_final_teardown(struct domain *d);
 void sh_do_mark_dirty(struct domain *d, mfn_t gmfn);
 static inline void mark_dirty(struct domain *d, unsigned long gmfn)
 {
-    int caller_locked;
-
-    if ( unlikely(d == NULL) || likely(!shadow_mode_log_dirty(d)) )
+    if ( likely(!shadow_mode_log_dirty(d)) )
         return;
 
-    caller_locked = shadow_lock_is_acquired(d);
-    if ( !caller_locked )
-        shadow_lock(d);
+    shadow_lock(d);
     sh_do_mark_dirty(d, _mfn(gmfn));
-    if ( !caller_locked )
-        shadow_unlock(d);
+    shadow_unlock(d);
 }
 
 /* Internal version, for when the shadow lock is already held */
 static inline void sh_mark_dirty(struct domain *d, mfn_t gmfn)
 {
     ASSERT(shadow_lock_is_acquired(d));
-    if ( shadow_mode_log_dirty(d) )
+    if ( unlikely(shadow_mode_log_dirty(d)) )
         sh_do_mark_dirty(d, gmfn);
 }