Index: /trunk/src/VBox/VMM/include/CPUMInternal.h
===================================================================
--- /trunk/src/VBox/VMM/include/CPUMInternal.h	(revision 55048)
+++ /trunk/src/VBox/VMM/include/CPUMInternal.h	(revision 55049)
@@ -385,5 +385,5 @@
 
     /* padding to get 64byte aligned size */
-    uint8_t         auPadding[16+12];
+    uint8_t         auPadding[16+20];
 
 #elif HC_ARCH_BITS == 64 || defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
@@ -447,4 +447,5 @@
     R3PTRTYPE(PX86XSAVEAREA)    pXStateR3;
 } CPUMHOSTCTX;
+AssertCompileSizeAlignment(CPUMHOSTCTX, 64);
 /** Pointer to the saved host CPU state. */
 typedef CPUMHOSTCTX *PCPUMHOSTCTX;
Index: /trunk/src/VBox/VMM/include/CPUMInternal.mac
===================================================================
--- /trunk/src/VBox/VMM/include/CPUMInternal.mac	(revision 55048)
+++ /trunk/src/VBox/VMM/include/CPUMInternal.mac	(revision 55049)
@@ -332,5 +332,5 @@
     .Host.SysEnter.esp   resq    1
     .Host.efer           resq    1
-    .Host.auPadding      resb    (16+12)
+    .Host.auPadding      resb    (16+20)
 
 %else ; 64-bit
Index: /trunk/src/VBox/VMM/testcase/tstHelp.h
===================================================================
--- /trunk/src/VBox/VMM/testcase/tstHelp.h	(revision 55048)
+++ /trunk/src/VBox/VMM/testcase/tstHelp.h	(revision 55049)
@@ -37,5 +37,6 @@
         if (off != RT_OFFSETOF(type, m)) \
         { \
-            printf("error! %#010x %s  Off by %d!! (off=%#x)\n", RT_OFFSETOF(type, m), #type "." #m, off - RT_OFFSETOF(type, m), off); \
+            printf("error! %#010x %s  Off by %d!! (expected off=%#x)\n", \
+                   RT_OFFSETOF(type, m), #type "." #m, off - RT_OFFSETOF(type, m), off); \
             rc++; \
         } \
@@ -53,5 +54,6 @@
         if (size != sizeof(type)) \
         { \
-            printf("error! sizeof(%s): %#x (%d)  Off by %d!!\n", #type, (int)sizeof(type), (int)sizeof(type), (int)(sizeof(type) - size)); \
+            printf("error! sizeof(%s): %#x (%d)  Off by %d!! (expected %#x)\n", \
+                   #type, (int)sizeof(type), (int)sizeof(type), (int)(sizeof(type) - size, size)); \
             rc++; \
         } \