[Xen-changelog] [xen-unstable] x86: Fix mod_l3_entry() for PAE-on-64 guests. The adjustment of

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

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1203342625 0
# Node ID 9d29141a5e527d13c10b592c5b7807af73750a19
# Parent  eb418cb71d4ba6c22f4d6dabd23600183124d797
x86: Fix mod_l3_entry() for PAE-on-64 guests. The adjustment of
_PAGE_RW and _PAGE_USER cannot happen before get_page_from_l3e().

Original patch by Manuel Bouyer <bouyer@xxxxxxxxxx>.
Signed-off-by: Christoph Egger <Christoph.Egger@xxxxxxx>
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
 xen/arch/x86/mm.c |   30 +++++++++++++++++++-----------
 1 files changed, 19 insertions(+), 11 deletions(-)

diff -r eb418cb71d4b -r 9d29141a5e52 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Mon Feb 18 09:35:39 2008 +0000
+++ b/xen/arch/x86/mm.c Mon Feb 18 13:50:25 2008 +0000
@@ -1443,16 +1443,18 @@ static int mod_l1_entry(l1_pgentry_t *pl
             return 0;
         }
 
-        adjust_guest_l1e(nl1e, d);
-
         /* Fast path for identical mapping, r/w and presence. */
         if ( !l1e_has_changed(ol1e, nl1e, _PAGE_RW | _PAGE_PRESENT) )
+        {
+            adjust_guest_l1e(nl1e, d);
             return UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr,
                                 preserve_ad);
+        }
 
         if ( unlikely(!get_page_from_l1e(nl1e, FOREIGNDOM)) )
             return 0;
         
+        adjust_guest_l1e(nl1e, d);
         if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr,
                                     preserve_ad)) )
         {
@@ -1501,15 +1503,17 @@ static int mod_l2_entry(l2_pgentry_t *pl
             return 0;
         }
 
-        adjust_guest_l2e(nl2e, d);
-
         /* Fast path for identical mapping and presence. */
-        if ( !l2e_has_changed(ol2e, nl2e, _PAGE_PRESENT))
+        if ( !l2e_has_changed(ol2e, nl2e, _PAGE_PRESENT) )
+        {
+            adjust_guest_l2e(nl2e, d);
             return UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr, preserve_ad);
+        }
 
         if ( unlikely(!get_page_from_l2e(nl2e, pfn, d)) )
             return 0;
 
+        adjust_guest_l2e(nl2e, d);
         if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr,
                                     preserve_ad)) )
         {
@@ -1567,15 +1571,17 @@ static int mod_l3_entry(l3_pgentry_t *pl
             return 0;
         }
 
-        adjust_guest_l3e(nl3e, d);
-
         /* Fast path for identical mapping and presence. */
-        if (!l3e_has_changed(ol3e, nl3e, _PAGE_PRESENT))
+        if ( !l3e_has_changed(ol3e, nl3e, _PAGE_PRESENT) )
+        {
+            adjust_guest_l3e(nl3e, d);
             return UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr, preserve_ad);
+        }
 
         if ( unlikely(!get_page_from_l3e(nl3e, pfn, d)) )
             return 0;
 
+        adjust_guest_l3e(nl3e, d);
         if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr,
                                     preserve_ad)) )
         {
@@ -1630,15 +1636,17 @@ static int mod_l4_entry(l4_pgentry_t *pl
             return 0;
         }
 
-        adjust_guest_l4e(nl4e, d);
-
         /* Fast path for identical mapping and presence. */
-        if (!l4e_has_changed(ol4e, nl4e, _PAGE_PRESENT))
+        if ( !l4e_has_changed(ol4e, nl4e, _PAGE_PRESENT) )
+        {
+            adjust_guest_l4e(nl4e, d);
             return UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr, preserve_ad);
+        }
 
         if ( unlikely(!get_page_from_l4e(nl4e, pfn, d)) )
             return 0;
 
+        adjust_guest_l4e(nl4e, d);
         if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr,
                                     preserve_ad)) )
         {

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