Index: /trunk/src/VBox/VMM/VMMR0/GMMR0.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMR0/GMMR0.cpp	(revision 30901)
+++ /trunk/src/VBox/VMM/VMMR0/GMMR0.cpp	(revision 30902)
@@ -3821,8 +3821,11 @@
  *
  * Performs the following tasks:
- * - if a shared page is new, then it changes the GMM page type to shared and returns it in the pPageDesc descriptor
- * - if a shared page already exists, then it checks if the VM page is identical and if so frees the VM page and returns the shared page in pPageDesc descriptor
- *
- * Note: assumes the caller has acquired the GMM semaphore!!
+ *  - If a shared page is new, then it changes the GMM page type to shared and
+ *    returns it in the pPageDesc descriptor.
+ *  - If a shared page already exists, then it checks if the VM page is
+ *    identical and if so frees the VM page and returns the shared page in
+ *    pPageDesc descriptor.
+ *
+ * @remarks ASSUMES the caller has acquired the GMM semaphore!!
  *
  * @returns VBox status code.
@@ -3834,5 +3837,6 @@
  * @param   paPageDesc          Page descriptor
  */
-GMMR0DECL(int) GMMR0SharedModuleCheckPage(PGVM pGVM, PGMMSHAREDMODULE pModule, unsigned idxRegion, unsigned idxPage, PGMMSHAREDPAGEDESC pPageDesc)
+GMMR0DECL(int) GMMR0SharedModuleCheckPage(PGVM pGVM, PGMMSHAREDMODULE pModule, unsigned idxRegion, unsigned idxPage,
+                                          PGMMSHAREDPAGEDESC pPageDesc)
 {
     int rc = VINF_SUCCESS;
@@ -3873,4 +3877,6 @@
         if (!pPage)
         {
+            Log(("GMMR0SharedModuleCheckPage: Invalid idPage=%#x #1 (GCPhys=%RGp HCPhys=%RHp idxRegion=%#x idxPage=%#x)\n",
+                 pPageDesc->uHCPhysPageId, pPageDesc->GCPhys, pPageDesc->HCPhys, idxRegion, idxPage));
             AssertFailed();
             rc = VERR_PGM_PHYS_INVALID_PAGE_ID;
@@ -3899,4 +3905,6 @@
         if (!pPage)
         {
+            Log(("GMMR0SharedModuleCheckPage: Invalid idPage=%#x #2 (idxRegion=%#x idxPage=%#x)\n",
+                 pPageDesc->uHCPhysPageId, idxRegion, idxPage));
             AssertFailed();
             rc = VERR_PGM_PHYS_INVALID_PAGE_ID;
@@ -3920,4 +3928,5 @@
             if (!gmmR0IsChunkMapped(pGVM, pChunk, (PRTR3PTR)&pbChunk))
             {
+                Log(("GMMR0SharedModuleCheckPage: Invalid idPage=%#x #3\n", pPageDesc->uHCPhysPageId));
                 AssertFailed();
                 rc = VERR_PGM_PHYS_INVALID_PAGE_ID;
@@ -3928,4 +3937,5 @@
         else
         {
+            Log(("GMMR0SharedModuleCheckPage: Invalid idPage=%#x #4\n", pPageDesc->uHCPhysPageId));
             AssertFailed();
             rc = VERR_PGM_PHYS_INVALID_PAGE_ID;