Index: /trunk/src/VBox/HostDrivers/VBoxPci/VBoxPciInternal.h
===================================================================
--- /trunk/src/VBox/HostDrivers/VBoxPci/VBoxPciInternal.h	(revision 50778)
+++ /trunk/src/VBox/HostDrivers/VBoxPci/VBoxPciInternal.h	(revision 50779)
@@ -95,4 +95,6 @@
     /** Pointer to per-VM context in hypervisor data. */
     PRAWPCIPERVM       pVmCtx;
+
+    RTR0PTR            aRegionR0Mapping[/* XXX: magic */ 7];
 } VBOXRAWPCIINS;
 
Index: /trunk/src/VBox/HostDrivers/VBoxPci/linux/VBoxPci-linux.c
===================================================================
--- /trunk/src/VBox/HostDrivers/VBoxPci/linux/VBoxPci-linux.c	(revision 50778)
+++ /trunk/src/VBox/HostDrivers/VBoxPci/linux/VBoxPci-linux.c	(revision 50779)
@@ -652,4 +652,15 @@
     if (pPciDev)
     {
+        int iRegion;
+        for (iRegion = 0; iRegion < 7; ++iRegion)
+        {
+            if (pIns->aRegionR0Mapping[iRegion])
+            {
+                iounmap(pIns->aRegionR0Mapping[iRegion]);
+                pIns->aRegionR0Mapping[iRegion] = 0;
+                pci_release_region(pPciDev, iRegion);
+            }
+        }
+
         vboxPciOsDevUnregisterWithIommu(pIns);
 
@@ -738,11 +749,11 @@
 {
     struct pci_dev  *pPciDev = pIns->pPciDev;
-    struct resource *pRegion;
     RTR0PTR          result = 0;
+    int              error;
 
     printk(KERN_DEBUG "linux vboxPciOsDevMapRegion: reg=%d start=%llx size=%lld\n", iRegion, RegionStart, u64RegionSize);
 
     if (!pPciDev)
-        return 0;
+        return VERR_INVALID_PARAMETER;
 
     if (iRegion < 0 || iRegion > 6)
@@ -752,25 +763,42 @@
     }
 
-    pRegion = request_mem_region(RegionStart, u64RegionSize, "vboxpci");
-    if (!pRegion)
-    {
-        /** @todo: need to make sure if thise error indeed can be ignored. */
-        printk(KERN_DEBUG "request_mem_region() failed, don't care\n");
-    }
+    if (pci_resource_flags(pPciDev, iRegion) & IORESOURCE_IO)
+        return VERR_INVALID_PARAMETER;
+
+    if (RegionStart != pci_resource_start(pPciDev, iRegion))
+        return VERR_INVALID_PARAMETER;
+
+    if (u64RegionSize != pci_resource_len(pPciDev, iRegion))
+        return VERR_INVALID_PARAMETER;
+
+    /*
+     * XXX: Current code never calls unmap.  To avoid leaking mappings
+     * only request and map resources once.
+     */
+    if (pIns->aRegionR0Mapping[iRegion])
+    {
+        *pRegionBase = pIns->aRegionR0Mapping[iRegion];
+        return VINF_SUCCESS;
+    }
+
+
+    error = pci_request_region(pPciDev, iRegion, "vboxpci");
+    if (error)
+        return VERR_RESOURCE_BUSY;
 
     /* For now no caching, try to optimize later. */
-    result = ioremap_nocache(RegionStart, u64RegionSize);
+    result = ioremap_nocache(pci_resource_start(pPciDev, iRegion),
+                             pci_resource_len(pPciDev, iRegion));
 
     if (!result)
     {
         printk(KERN_DEBUG "cannot ioremap_nocache\n");
-        if (pRegion)
-            release_mem_region(RegionStart, u64RegionSize);
-        return 0;
-    }
-
-    *pRegionBase = result;
-
-    return 0;
+        pci_release_region(pPciDev, iRegion);
+        return VERR_MAP_FAILED;
+    }
+
+    *pRegionBase = pIns->aRegionR0Mapping[iRegion] = result;
+
+    return VINF_SUCCESS;
 }
 
@@ -781,9 +809,6 @@
                              RTR0PTR        RegionBase)
 {
-
-    iounmap(RegionBase);
-    release_mem_region(RegionStart, u64RegionSize);
-
-    return VINF_SUCCESS;
+    /* XXX: Current code never calls unmap. */
+    return VERR_NOT_IMPLEMENTED;
 }