Index: /trunk/include/VBox/VBoxVideoHost3D.h
===================================================================
--- /trunk/include/VBox/VBoxVideoHost3D.h	(revision 50798)
+++ /trunk/include/VBox/VBoxVideoHost3D.h	(revision 50799)
@@ -117,5 +117,5 @@
 typedef struct VBOXVDMAHOST * HVBOXCRCMDCTL_REMAINING_HOST_COMMAND;
 
-typedef DECLCALLBACKPTR(VBOXCRCMDCTL*, PFNVBOXCRCMDCTL_REMAINING_HOST_COMMAND)(HVBOXCRCMDCTL_REMAINING_HOST_COMMAND hClient, uint32_t *pcbCtl, int prevCmdRc);
+typedef DECLCALLBACKPTR(uint8_t*, PFNVBOXCRCMDCTL_REMAINING_HOST_COMMAND)(HVBOXCRCMDCTL_REMAINING_HOST_COMMAND hClient, uint32_t *pcbCtl, int prevCmdRc);
 
 typedef struct VBOXCRCMDCTL_ENABLE
Index: /trunk/src/VBox/Devices/Graphics/DevVGA_VDMA.cpp
===================================================================
--- /trunk/src/VBox/Devices/Graphics/DevVGA_VDMA.cpp	(revision 50798)
+++ /trunk/src/VBox/Devices/Graphics/DevVGA_VDMA.cpp	(revision 50799)
@@ -942,5 +942,5 @@
 }
 
-static DECLCALLBACK(VBOXCRCMDCTL*) vboxVDMACrHgcmHandleEnableRemainingHostCommand(HVBOXCRCMDCTL_REMAINING_HOST_COMMAND hClient, uint32_t *pcbCtl, int prevCmdRc)
+static DECLCALLBACK(uint8_t*) vboxVDMACrHgcmHandleEnableRemainingHostCommand(HVBOXCRCMDCTL_REMAINING_HOST_COMMAND hClient, uint32_t *pcbCtl, int prevCmdRc)
 {
     struct VBOXVDMAHOST *pVdma = hClient;
@@ -959,5 +959,5 @@
     {
         *pcbCtl = pVdma->pCurRemainingHostCtl->u.cmd.cbCmd;
-        return (VBOXCRCMDCTL*)pVdma->pCurRemainingHostCtl->u.cmd.pu8Cmd;
+        return pVdma->pCurRemainingHostCtl->u.cmd.pu8Cmd;
     }
 
Index: /trunk/src/VBox/GuestHost/OpenGL/include/cr_server.h
===================================================================
--- /trunk/src/VBox/GuestHost/OpenGL/include/cr_server.h	(revision 50798)
+++ /trunk/src/VBox/GuestHost/OpenGL/include/cr_server.h	(revision 50799)
@@ -569,4 +569,7 @@
 #endif
 
+extern DECLEXPORT(int32_t) crVBoxServerHgcmEnable(HVBOXCRCMDCTL_REMAINING_HOST_COMMAND hRHCmd, PFNVBOXCRCMDCTL_REMAINING_HOST_COMMAND pfnRHCmd);
+extern DECLEXPORT(int32_t) crVBoxServerHgcmDisable();
+
 #ifdef __cplusplus
 }
Index: /trunk/src/VBox/HostServices/SharedOpenGL/crserverlib/server_main.c
===================================================================
--- /trunk/src/VBox/HostServices/SharedOpenGL/crserverlib/server_main.c	(revision 50798)
+++ /trunk/src/VBox/HostServices/SharedOpenGL/crserverlib/server_main.c	(revision 50799)
@@ -3651,3 +3651,66 @@
 }
 
+void crVBoxServerDefaultContextSet()
+{
+    GLint spuWindow, spuCtx;
+
+    if (cr_server.MainContextInfo.SpuContext)
+    {
+        CRMuralInfo *pMural = crServerGetDummyMural(cr_server.MainContextInfo.CreateInfo.realVisualBits);
+        if (!pMural)
+        {
+            WARN(("dummy mural is NULL"));
+            spuCtx = CR_RENDER_DEFAULT_CONTEXT_ID;
+            spuWindow = CR_RENDER_DEFAULT_WINDOW_ID;
+        }
+        else
+        {
+            spuCtx = cr_server.MainContextInfo.SpuContext;
+            spuWindow = pMural->CreateInfo.realVisualBits;
+        }
+    }
+    else
+    {
+        spuCtx = CR_RENDER_DEFAULT_CONTEXT_ID;
+        spuWindow = CR_RENDER_DEFAULT_WINDOW_ID;
+    }
+
+    cr_server.head_spu->dispatch_table.MakeCurrent(spuWindow, 0, spuCtx);
+}
+
+int32_t crVBoxServerHgcmEnable(HVBOXCRCMDCTL_REMAINING_HOST_COMMAND hRHCmd, PFNVBOXCRCMDCTL_REMAINING_HOST_COMMAND pfnRHCmd)
+{
+    int rc = VINF_SUCCESS;
+    uint8_t* pCtl;
+    uint32_t cbCtl;
+
+    if (cr_server.numClients)
+    {
+        WARN(("cr_server.numClients(%d) is not NULL", cr_server.numClients));
+        return VERR_INVALID_STATE;
+    }
+
+    for (pCtl = pfnRHCmd(hRHCmd, &cbCtl, rc); pCtl; pCtl = pfnRHCmd(hRHCmd, &cbCtl, rc))
+    {
+        rc = crVBoxCrCmdHostCtl(NULL, pCtl, cbCtl);
+    }
+
+    crVBoxServerDefaultContextSet();
+
+    return VINF_SUCCESS;
+}
+
+int32_t crVBoxServerHgcmDisable()
+{
+    if (cr_server.numClients)
+    {
+        WARN(("cr_server.numClients(%d) is not NULL", cr_server.numClients));
+        return VERR_INVALID_STATE;
+    }
+
+    cr_server.head_spu->dispatch_table.MakeCurrent(0, 0, 0);
+
+    return VINF_SUCCESS;
+}
+
 #endif