[Xen-changelog] [xen-unstable] x86: No need to flush TLBs on free_page_type() as we no longer trust

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

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1233757693 0
# Node ID 398291c661b3a3fc8332619f13e17f8e781a3aec
# Parent  faf20eb0b69e338668ecbb9f4714b70eba841ce6
x86: No need to flush TLBs on free_page_type() as we no longer trust
the linear pagetable mapping (we use it but we double check it).

Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
 xen/arch/x86/mm.c |   35 +++++++++++------------------------
 1 files changed, 11 insertions(+), 24 deletions(-)

diff -r faf20eb0b69e -r 398291c661b3 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Wed Feb 04 13:27:17 2009 +0000
+++ b/xen/arch/x86/mm.c Wed Feb 04 14:28:13 2009 +0000
@@ -2023,30 +2023,17 @@ int free_page_type(struct page_info *pag
     unsigned long gmfn;
     int rc;
 
-    if ( likely(owner != NULL) )
-    {
-        /*
-         * We have to flush before the next use of the linear mapping
-         * (e.g., update_va_mapping()) or we could end up modifying a page
-         * that is no longer a page table (and hence screw up ref counts).
-         */
-        if ( current->domain == owner )
-            queue_deferred_ops(owner, DOP_FLUSH_ALL_TLBS);
-        else
-            flush_tlb_mask(owner->domain_dirty_cpumask);
-
-        if ( unlikely(paging_mode_enabled(owner)) )
-        {
-            /* A page table is dirtied when its type count becomes zero. */
-            paging_mark_dirty(owner, page_to_mfn(page));
-
-            if ( shadow_mode_refcounts(owner) )
-                return 0;
-
-            gmfn = mfn_to_gmfn(owner, page_to_mfn(page));
-            ASSERT(VALID_M2P(gmfn));
-            shadow_remove_all_shadows(owner->vcpu[0], _mfn(gmfn));
-        }
+    if ( likely(owner != NULL) && unlikely(paging_mode_enabled(owner)) )
+    {
+        /* A page table is dirtied when its type count becomes zero. */
+        paging_mark_dirty(owner, page_to_mfn(page));
+
+        if ( shadow_mode_refcounts(owner) )
+            return 0;
+
+        gmfn = mfn_to_gmfn(owner, page_to_mfn(page));
+        ASSERT(VALID_M2P(gmfn));
+        shadow_remove_all_shadows(owner->vcpu[0], _mfn(gmfn));
     }
 
     if ( !(type & PGT_partial) )

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