From: kaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Date: Sat, 14 Jan 2006 09:35:39 +0000 (+0100)
Subject: Fix the issue of system crash in vmx stress test.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~16541^2~39
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=b395f5ac6dc412c103599a4da3b74cf8ea4bdb0c;p=xen.git

Fix the issue of system crash in vmx stress test.
There is a path that shadow L2 table is assigned
after it is unshadowed in stress test.

Signed-off-by: Xiaofeng Ling <xiaofeng.ling@intel.com>
---

diff --git a/xen/arch/x86/shadow.c b/xen/arch/x86/shadow.c
index b2fd143452..6ae54e208a 100644
--- a/xen/arch/x86/shadow.c
+++ b/xen/arch/x86/shadow.c
@@ -2138,6 +2138,7 @@ static void shadow_update_pagetables(struct vcpu *v)
 #if CONFIG_PAGING_LEVELS == 2
     unsigned long hl2mfn;
 #endif
+    int need_sync = 0;
 
     int max_mode = ( shadow_mode_external(d) ? SHM_external
                      : shadow_mode_translate(d) ? SHM_translate
@@ -2169,8 +2170,17 @@ static void shadow_update_pagetables(struct vcpu *v)
 #elif CONFIG_PAGING_LEVELS == 4
         smfn = shadow_l4_table(d, gpfn, gmfn);
 #endif
-    }else
-        shadow_sync_all(d);
+    }
+    else
+    {
+        /*
+         *  move sync later in order to avoid this smfn been 
+         *  unshadowed occasionally
+         */
+        need_sync = 1;
+    }
+
+
     if ( !get_shadow_ref(smfn) )
         BUG();
     old_smfn = pagetable_get_pfn(v->arch.shadow_table);
@@ -2241,6 +2251,9 @@ static void shadow_update_pagetables(struct vcpu *v)
     }
 #endif /* CONFIG_PAGING_LEVELS == 2 */
 
+    if(likely(need_sync))
+        shadow_sync_all(d);
+
 #if CONFIG_PAGING_LEVELS == 3
     /* FIXME: PAE code to be written */
 #endif
diff --git a/xen/arch/x86/shadow32.c b/xen/arch/x86/shadow32.c
index eb09ea92c5..a36238b3d8 100644
--- a/xen/arch/x86/shadow32.c
+++ b/xen/arch/x86/shadow32.c
@@ -2896,6 +2896,7 @@ void __update_pagetables(struct vcpu *v)
     unsigned long gmfn = pagetable_get_pfn(v->arch.guest_table);
     unsigned long gpfn = __mfn_to_gpfn(d, gmfn);
     unsigned long smfn, hl2mfn, old_smfn;
+    int need_sync = 0;
 
     int max_mode = ( shadow_mode_external(d) ? SHM_external
                      : shadow_mode_translate(d) ? SHM_translate
@@ -2921,7 +2922,13 @@ void __update_pagetables(struct vcpu *v)
     if ( unlikely(!(smfn = __shadow_status(d, gpfn, PGT_base_page_table))) )
         smfn = shadow_l2_table(d, gpfn, gmfn);
     else
-        shadow_sync_all(d);
+    {
+        /*
+         *  move sync later in order to avoid this smfn been 
+         *  unshadowed occasionally
+         */
+        need_sync = 1;
+    }
     if ( !get_shadow_ref(smfn) )
         BUG();
     old_smfn = pagetable_get_pfn(v->arch.shadow_table);
@@ -2985,6 +2992,9 @@ void __update_pagetables(struct vcpu *v)
         // XXX - maybe this can be optimized somewhat??
         local_flush_tlb();
     }
+
+    if(likely(need_sync))
+        shadow_sync_all(d);
 }
 
 void clear_all_shadow_status(struct domain *d)