Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1768 insertions, 0 deletions

diff --git a/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c b/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c
new file mode 100644
index 00000000..d6f39400
--- /dev/null
+++ b/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c
@@ -0,0 +1,1768 @@
+/* $Id: memobj-r0drv-linux.c $ */
+/** @file
+ * IPRT - Ring-0 Memory Objects, Linux.
+ */
+
+/*
+ * Copyright (C) 2006-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "the-linux-kernel.h"
+
+#include <iprt/memobj.h>
+#include <iprt/assert.h>
+#include <iprt/err.h>
+#include <iprt/log.h>
+#include <iprt/mem.h>
+#include <iprt/process.h>
+#include <iprt/string.h>
+#include "internal/memobj.h"
+
+
+/*********************************************************************************************************************************
+*   Defined Constants And Macros                                                                                                 *
+*********************************************************************************************************************************/
+/* early 2.6 kernels */
+#ifndef PAGE_SHARED_EXEC
+# define PAGE_SHARED_EXEC PAGE_SHARED
+#endif
+#ifndef PAGE_READONLY_EXEC
+# define PAGE_READONLY_EXEC PAGE_READONLY
+#endif
+
+/*
+ * 2.6.29+ kernels don't work with remap_pfn_range() anymore because
+ * track_pfn_vma_new() is apparently not defined for non-RAM pages.
+ * It should be safe to use vm_insert_page() older kernels as well.
+ */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 23)
+# define VBOX_USE_INSERT_PAGE
+#endif
+#if    defined(CONFIG_X86_PAE) \
+    && (   defined(HAVE_26_STYLE_REMAP_PAGE_RANGE) \
+        || (   LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) \
+            && LINUX_VERSION_CODE <  KERNEL_VERSION(2, 6, 11)))
+# define VBOX_USE_PAE_HACK
+#endif
+
+
+/*********************************************************************************************************************************
+*   Structures and Typedefs                                                                                                      *
+*********************************************************************************************************************************/
+/**
+ * The Darwin version of the memory object structure.
+ */
+typedef struct RTR0MEMOBJLNX
+{
+    /** The core structure. */
+    RTR0MEMOBJINTERNAL  Core;
+    /** Set if the allocation is contiguous.
+     * This means it has to be given back as one chunk. */
+    bool                fContiguous;
+    /** Set if we've vmap'ed the memory into ring-0. */
+    bool                fMappedToRing0;
+    /** The pages in the apPages array. */
+    size_t              cPages;
+    /** Array of struct page pointers. (variable size) */
+    struct page        *apPages[1];
+} RTR0MEMOBJLNX, *PRTR0MEMOBJLNX;
+
+
+static void rtR0MemObjLinuxFreePages(PRTR0MEMOBJLNX pMemLnx);
+
+
+/**
+ * Helper that converts from a RTR0PROCESS handle to a linux task.
+ *
+ * @returns The corresponding Linux task.
+ * @param   R0Process   IPRT ring-0 process handle.
+ */
+static struct task_struct *rtR0ProcessToLinuxTask(RTR0PROCESS R0Process)
+{
+    /** @todo fix rtR0ProcessToLinuxTask!! */
+    /** @todo many (all?) callers currently assume that we return 'current'! */
+    return R0Process == RTR0ProcHandleSelf() ? current : NULL;
+}
+
+
+/**
+ * Compute order. Some functions allocate 2^order pages.
+ *
+ * @returns order.
+ * @param   cPages      Number of pages.
+ */
+static int rtR0MemObjLinuxOrder(size_t cPages)
+{
+    int     iOrder;
+    size_t  cTmp;
+
+    for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
+        ;
+    if (cPages & ~((size_t)1 << iOrder))
+        ++iOrder;
+
+    return iOrder;
+}
+
+
+/**
+ * Converts from RTMEM_PROT_* to Linux PAGE_*.
+ *
+ * @returns Linux page protection constant.
+ * @param   fProt       The IPRT protection mask.
+ * @param   fKernel     Whether it applies to kernel or user space.
+ */
+static pgprot_t rtR0MemObjLinuxConvertProt(unsigned fProt, bool fKernel)
+{
+    switch (fProt)
+    {
+        default:
+            AssertMsgFailed(("%#x %d\n", fProt, fKernel));
+        case RTMEM_PROT_NONE:
+            return PAGE_NONE;
+
+        case RTMEM_PROT_READ:
+            return fKernel ? PAGE_KERNEL_RO         : PAGE_READONLY;
+
+        case RTMEM_PROT_WRITE:
+        case RTMEM_PROT_WRITE | RTMEM_PROT_READ:
+            return fKernel ? PAGE_KERNEL            : PAGE_SHARED;
+
+        case RTMEM_PROT_EXEC:
+        case RTMEM_PROT_EXEC | RTMEM_PROT_READ:
+#if defined(RT_ARCH_X86) || defined(RT_ARCH_AMD64)
+            if (fKernel)
+            {
+                pgprot_t fPg = MY_PAGE_KERNEL_EXEC;
+                pgprot_val(fPg) &= ~_PAGE_RW;
+                return fPg;
+            }
+            return PAGE_READONLY_EXEC;
+#else
+            return fKernel ? MY_PAGE_KERNEL_EXEC    : PAGE_READONLY_EXEC;
+#endif
+
+        case RTMEM_PROT_WRITE | RTMEM_PROT_EXEC:
+        case RTMEM_PROT_WRITE | RTMEM_PROT_EXEC | RTMEM_PROT_READ:
+            return fKernel ? MY_PAGE_KERNEL_EXEC    : PAGE_SHARED_EXEC;
+    }
+}
+
+
+/**
+ * Worker for rtR0MemObjNativeReserveUser and rtR0MemObjNativerMapUser that creates
+ * an empty user space mapping.
+ *
+ * We acquire the mmap_sem of the task!
+ *
+ * @returns Pointer to the mapping.
+ *          (void *)-1 on failure.
+ * @param   R3PtrFixed  (RTR3PTR)-1 if anywhere, otherwise a specific location.
+ * @param   cb          The size of the mapping.
+ * @param   uAlignment  The alignment of the mapping.
+ * @param   pTask       The Linux task to create this mapping in.
+ * @param   fProt       The RTMEM_PROT_* mask.
+ */
+static void *rtR0MemObjLinuxDoMmap(RTR3PTR R3PtrFixed, size_t cb, size_t uAlignment, struct task_struct *pTask, unsigned fProt)
+{
+    unsigned fLnxProt;
+    unsigned long ulAddr;
+
+    Assert(pTask == current); /* do_mmap */
+    RT_NOREF_PV(pTask);
+
+    /*
+     * Convert from IPRT protection to mman.h PROT_ and call do_mmap.
+     */
+    fProt &= (RTMEM_PROT_NONE | RTMEM_PROT_READ | RTMEM_PROT_WRITE | RTMEM_PROT_EXEC);
+    if (fProt == RTMEM_PROT_NONE)
+        fLnxProt = PROT_NONE;
+    else
+    {
+        fLnxProt = 0;
+        if (fProt & RTMEM_PROT_READ)
+            fLnxProt |= PROT_READ;
+        if (fProt & RTMEM_PROT_WRITE)
+            fLnxProt |= PROT_WRITE;
+        if (fProt & RTMEM_PROT_EXEC)
+            fLnxProt |= PROT_EXEC;
+    }
+
+    if (R3PtrFixed != (RTR3PTR)-1)
+    {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 5, 0)
+        ulAddr = vm_mmap(NULL, R3PtrFixed, cb, fLnxProt, MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, 0);
+#else
+        down_write(&pTask->mm->mmap_sem);
+        ulAddr = do_mmap(NULL, R3PtrFixed, cb, fLnxProt, MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, 0);
+        up_write(&pTask->mm->mmap_sem);
+#endif
+    }
+    else
+    {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 5, 0)
+        ulAddr = vm_mmap(NULL, 0, cb, fLnxProt, MAP_SHARED | MAP_ANONYMOUS, 0);
+#else
+        down_write(&pTask->mm->mmap_sem);
+        ulAddr = do_mmap(NULL, 0, cb, fLnxProt, MAP_SHARED | MAP_ANONYMOUS, 0);
+        up_write(&pTask->mm->mmap_sem);
+#endif
+        if (    !(ulAddr & ~PAGE_MASK)
+            &&  (ulAddr & (uAlignment - 1)))
+        {
+            /** @todo implement uAlignment properly... We'll probably need to make some dummy mappings to fill
+             * up alignment gaps. This is of course complicated by fragmentation (which we might have cause
+             * ourselves) and further by there begin two mmap strategies (top / bottom). */
+            /* For now, just ignore uAlignment requirements... */
+        }
+    }
+
+
+    if (ulAddr & ~PAGE_MASK) /* ~PAGE_MASK == PAGE_OFFSET_MASK */
+        return (void *)-1;
+    return (void *)ulAddr;
+}
+
+
+/**
+ * Worker that destroys a user space mapping.
+ * Undoes what rtR0MemObjLinuxDoMmap did.
+ *
+ * We acquire the mmap_sem of the task!
+ *
+ * @param   pv          The ring-3 mapping.
+ * @param   cb          The size of the mapping.
+ * @param   pTask       The Linux task to destroy this mapping in.
+ */
+static void rtR0MemObjLinuxDoMunmap(void *pv, size_t cb, struct task_struct *pTask)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 5, 0)
+    Assert(pTask == current); RT_NOREF_PV(pTask);
+    vm_munmap((unsigned long)pv, cb);
+#elif defined(USE_RHEL4_MUNMAP)
+    down_write(&pTask->mm->mmap_sem);
+    do_munmap(pTask->mm, (unsigned long)pv, cb, 0); /* should it be 1 or 0? */
+    up_write(&pTask->mm->mmap_sem);
+#else
+    down_write(&pTask->mm->mmap_sem);
+    do_munmap(pTask->mm, (unsigned long)pv, cb);
+    up_write(&pTask->mm->mmap_sem);
+#endif
+}
+
+
+/**
+ * Internal worker that allocates physical pages and creates the memory object for them.
+ *
+ * @returns IPRT status code.
+ * @param   ppMemLnx    Where to store the memory object pointer.
+ * @param   enmType     The object type.
+ * @param   cb          The number of bytes to allocate.
+ * @param   uAlignment  The alignment of the physical memory.
+ *                      Only valid if fContiguous == true, ignored otherwise.
+ * @param   fFlagsLnx   The page allocation flags (GPFs).
+ * @param   fContiguous Whether the allocation must be contiguous.
+ * @param   rcNoMem     What to return when we're out of pages.
+ */
+static int rtR0MemObjLinuxAllocPages(PRTR0MEMOBJLNX *ppMemLnx, RTR0MEMOBJTYPE enmType, size_t cb,
+                                     size_t uAlignment, unsigned fFlagsLnx, bool fContiguous, int rcNoMem)
+{
+    size_t          iPage;
+    size_t const    cPages = cb >> PAGE_SHIFT;
+    struct page    *paPages;
+
+    /*
+     * Allocate a memory object structure that's large enough to contain
+     * the page pointer array.
+     */
+    PRTR0MEMOBJLNX  pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(RT_UOFFSETOF_DYN(RTR0MEMOBJLNX, apPages[cPages]), enmType, NULL, cb);
+    if (!pMemLnx)
+        return VERR_NO_MEMORY;
+    pMemLnx->cPages = cPages;
+
+     if (cPages > 255)
+     {
+# ifdef __GFP_REPEAT
+         /* Try hard to allocate the memory, but the allocation attempt might fail. */
+        fFlagsLnx |= __GFP_REPEAT;
+# endif
+# ifdef __GFP_NOMEMALLOC
+        /* Introduced with Linux 2.6.12: Don't use emergency reserves */
+        fFlagsLnx |= __GFP_NOMEMALLOC;
+# endif
+     }
+
+    /*
+     * Allocate the pages.
+     * For small allocations we'll try contiguous first and then fall back on page by page.
+     */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+    if (    fContiguous
+        ||  cb <= PAGE_SIZE * 2)
+    {
+# ifdef VBOX_USE_INSERT_PAGE
+        paPages = alloc_pages(fFlagsLnx | __GFP_COMP | __GFP_NOWARN, rtR0MemObjLinuxOrder(cPages));
+# else
+        paPages = alloc_pages(fFlagsLnx | __GFP_NOWARN, rtR0MemObjLinuxOrder(cPages));
+# endif
+        if (paPages)
+        {
+            fContiguous = true;
+            for (iPage = 0; iPage < cPages; iPage++)
+                pMemLnx->apPages[iPage] = &paPages[iPage];
+        }
+        else if (fContiguous)
+        {
+            rtR0MemObjDelete(&pMemLnx->Core);
+            return rcNoMem;
+        }
+    }
+
+    if (!fContiguous)
+    {
+        for (iPage = 0; iPage < cPages; iPage++)
+        {
+            pMemLnx->apPages[iPage] = alloc_page(fFlagsLnx | __GFP_NOWARN);
+            if (RT_UNLIKELY(!pMemLnx->apPages[iPage]))
+            {
+                while (iPage-- > 0)
+                    __free_page(pMemLnx->apPages[iPage]);
+                rtR0MemObjDelete(&pMemLnx->Core);
+                return rcNoMem;
+            }
+        }
+    }
+
+#else /* < 2.4.22 */
+    /** @todo figure out why we didn't allocate page-by-page on 2.4.21 and older... */
+    paPages = alloc_pages(fFlagsLnx, rtR0MemObjLinuxOrder(cPages));
+    if (!paPages)
+    {
+        rtR0MemObjDelete(&pMemLnx->Core);
+        return rcNoMem;
+    }
+    for (iPage = 0; iPage < cPages; iPage++)
+    {
+        pMemLnx->apPages[iPage] = &paPages[iPage];
+        MY_SET_PAGES_EXEC(pMemLnx->apPages[iPage], 1);
+        if (PageHighMem(pMemLnx->apPages[iPage]))
+            BUG();
+    }
+
+    fContiguous = true;
+#endif /* < 2.4.22 */
+    pMemLnx->fContiguous = fContiguous;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 5, 0)
+    /*
+     * Reserve the pages.
+     *
+     * Linux >= 4.5 with CONFIG_DEBUG_VM panics when setting PG_reserved on compound
+     * pages. According to Michal Hocko this shouldn't be necessary anyway because
+     * as pages which are not on the LRU list are never evictable.
+     */
+    for (iPage = 0; iPage < cPages; iPage++)
+        SetPageReserved(pMemLnx->apPages[iPage]);
+#endif
+
+    /*
+     * Note that the physical address of memory allocated with alloc_pages(flags, order)
+     * is always 2^(PAGE_SHIFT+order)-aligned.
+     */
+    if (   fContiguous
+        && uAlignment > PAGE_SIZE)
+    {
+        /*
+         * Check for alignment constraints. The physical address of memory allocated with
+         * alloc_pages(flags, order) is always 2^(PAGE_SHIFT+order)-aligned.
+         */
+        if (RT_UNLIKELY(page_to_phys(pMemLnx->apPages[0]) & (uAlignment - 1)))
+        {
+            /*
+             * This should never happen!
+             */
+            printk("rtR0MemObjLinuxAllocPages(cb=0x%lx, uAlignment=0x%lx): alloc_pages(..., %d) returned physical memory at 0x%lx!\n",
+                    (unsigned long)cb, (unsigned long)uAlignment, rtR0MemObjLinuxOrder(cPages), (unsigned long)page_to_phys(pMemLnx->apPages[0]));
+            rtR0MemObjLinuxFreePages(pMemLnx);
+            return rcNoMem;
+        }
+    }
+
+    *ppMemLnx = pMemLnx;
+    return VINF_SUCCESS;
+}
+
+
+/**
+ * Frees the physical pages allocated by the rtR0MemObjLinuxAllocPages() call.
+ *
+ * This method does NOT free the object.
+ *
+ * @param   pMemLnx     The object which physical pages should be freed.
+ */
+static void rtR0MemObjLinuxFreePages(PRTR0MEMOBJLNX pMemLnx)
+{
+    size_t iPage = pMemLnx->cPages;
+    if (iPage > 0)
+    {
+        /*
+         * Restore the page flags.
+         */
+        while (iPage-- > 0)
+        {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 5, 0)
+            /*
+             * See SetPageReserved() in rtR0MemObjLinuxAllocPages()
+             */
+            ClearPageReserved(pMemLnx->apPages[iPage]);
+#endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+#else
+            MY_SET_PAGES_NOEXEC(pMemLnx->apPages[iPage], 1);
+#endif
+        }
+
+        /*
+         * Free the pages.
+         */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+        if (!pMemLnx->fContiguous)
+        {
+            iPage = pMemLnx->cPages;
+            while (iPage-- > 0)
+                __free_page(pMemLnx->apPages[iPage]);
+        }
+        else
+#endif
+            __free_pages(pMemLnx->apPages[0], rtR0MemObjLinuxOrder(pMemLnx->cPages));
+
+        pMemLnx->cPages = 0;
+    }
+}
+
+
+/**
+ * Maps the allocation into ring-0.
+ *
+ * This will update the RTR0MEMOBJLNX::Core.pv and RTR0MEMOBJ::fMappedToRing0 members.
+ *
+ * Contiguous mappings that isn't in 'high' memory will already be mapped into kernel
+ * space, so we'll use that mapping if possible. If execute access is required, we'll
+ * play safe and do our own mapping.
+ *
+ * @returns IPRT status code.
+ * @param   pMemLnx     The linux memory object to map.
+ * @param   fExecutable Whether execute access is required.
+ */
+static int rtR0MemObjLinuxVMap(PRTR0MEMOBJLNX pMemLnx, bool fExecutable)
+{
+    int rc = VINF_SUCCESS;
+
+    /*
+     * Choose mapping strategy.
+     */
+    bool fMustMap = fExecutable
+                 || !pMemLnx->fContiguous;
+    if (!fMustMap)
+    {
+        size_t iPage = pMemLnx->cPages;
+        while (iPage-- > 0)
+            if (PageHighMem(pMemLnx->apPages[iPage]))
+            {
+                fMustMap = true;
+                break;
+            }
+    }
+
+    Assert(!pMemLnx->Core.pv);
+    Assert(!pMemLnx->fMappedToRing0);
+
+    if (fMustMap)
+    {
+        /*
+         * Use vmap - 2.4.22 and later.
+         */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+        pgprot_t fPg;
+        pgprot_val(fPg) = _PAGE_PRESENT | _PAGE_RW;
+# ifdef _PAGE_NX
+        if (!fExecutable)
+            pgprot_val(fPg) |= _PAGE_NX;
+# endif
+
+# ifdef VM_MAP
+        pMemLnx->Core.pv = vmap(&pMemLnx->apPages[0], pMemLnx->cPages, VM_MAP, fPg);
+# else
+        pMemLnx->Core.pv = vmap(&pMemLnx->apPages[0], pMemLnx->cPages, VM_ALLOC, fPg);
+# endif
+        if (pMemLnx->Core.pv)
+            pMemLnx->fMappedToRing0 = true;
+        else
+            rc = VERR_MAP_FAILED;
+#else   /* < 2.4.22 */
+        rc = VERR_NOT_SUPPORTED;
+#endif
+    }
+    else
+    {
+        /*
+         * Use the kernel RAM mapping.
+         */
+        pMemLnx->Core.pv = phys_to_virt(page_to_phys(pMemLnx->apPages[0]));
+        Assert(pMemLnx->Core.pv);
+    }
+
+    return rc;
+}
+
+
+/**
+ * Undoes what rtR0MemObjLinuxVMap() did.
+ *
+ * @param   pMemLnx     The linux memory object.
+ */
+static void rtR0MemObjLinuxVUnmap(PRTR0MEMOBJLNX pMemLnx)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+    if (pMemLnx->fMappedToRing0)
+    {
+        Assert(pMemLnx->Core.pv);
+        vunmap(pMemLnx->Core.pv);
+        pMemLnx->fMappedToRing0 = false;
+    }
+#else /* < 2.4.22 */
+    Assert(!pMemLnx->fMappedToRing0);
+#endif
+    pMemLnx->Core.pv = NULL;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeFree(RTR0MEMOBJ pMem)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    PRTR0MEMOBJLNX pMemLnx = (PRTR0MEMOBJLNX)pMem;
+
+    /*
+     * Release any memory that we've allocated or locked.
+     */
+    switch (pMemLnx->Core.enmType)
+    {
+        case RTR0MEMOBJTYPE_LOW:
+        case RTR0MEMOBJTYPE_PAGE:
+        case RTR0MEMOBJTYPE_CONT:
+        case RTR0MEMOBJTYPE_PHYS:
+        case RTR0MEMOBJTYPE_PHYS_NC:
+            rtR0MemObjLinuxVUnmap(pMemLnx);
+            rtR0MemObjLinuxFreePages(pMemLnx);
+            break;
+
+        case RTR0MEMOBJTYPE_LOCK:
+            if (pMemLnx->Core.u.Lock.R0Process != NIL_RTR0PROCESS)
+            {
+                struct task_struct *pTask = rtR0ProcessToLinuxTask(pMemLnx->Core.u.Lock.R0Process);
+                size_t              iPage;
+                Assert(pTask);
+                if (pTask && pTask->mm)
+                    down_read(&pTask->mm->mmap_sem);
+
+                iPage = pMemLnx->cPages;
+                while (iPage-- > 0)
+                {
+                    if (!PageReserved(pMemLnx->apPages[iPage]))
+                        SetPageDirty(pMemLnx->apPages[iPage]);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
+                    put_page(pMemLnx->apPages[iPage]);
+#else
+                    page_cache_release(pMemLnx->apPages[iPage]);
+#endif
+                }
+
+                if (pTask && pTask->mm)
+                    up_read(&pTask->mm->mmap_sem);
+            }
+            /* else: kernel memory - nothing to do here. */
+            break;
+
+        case RTR0MEMOBJTYPE_RES_VIRT:
+            Assert(pMemLnx->Core.pv);
+            if (pMemLnx->Core.u.ResVirt.R0Process != NIL_RTR0PROCESS)
+            {
+                struct task_struct *pTask = rtR0ProcessToLinuxTask(pMemLnx->Core.u.Lock.R0Process);
+                Assert(pTask);
+                if (pTask && pTask->mm)
+                    rtR0MemObjLinuxDoMunmap(pMemLnx->Core.pv, pMemLnx->Core.cb, pTask);
+            }
+            else
+            {
+                vunmap(pMemLnx->Core.pv);
+
+                Assert(pMemLnx->cPages == 1 && pMemLnx->apPages[0] != NULL);
+                __free_page(pMemLnx->apPages[0]);
+                pMemLnx->apPages[0] = NULL;
+                pMemLnx->cPages = 0;
+            }
+            pMemLnx->Core.pv = NULL;
+            break;
+
+        case RTR0MEMOBJTYPE_MAPPING:
+            Assert(pMemLnx->cPages == 0); Assert(pMemLnx->Core.pv);
+            if (pMemLnx->Core.u.ResVirt.R0Process != NIL_RTR0PROCESS)
+            {
+                struct task_struct *pTask = rtR0ProcessToLinuxTask(pMemLnx->Core.u.Lock.R0Process);
+                Assert(pTask);
+                if (pTask && pTask->mm)
+                    rtR0MemObjLinuxDoMunmap(pMemLnx->Core.pv, pMemLnx->Core.cb, pTask);
+            }
+            else
+                vunmap(pMemLnx->Core.pv);
+            pMemLnx->Core.pv = NULL;
+            break;
+
+        default:
+            AssertMsgFailed(("enmType=%d\n", pMemLnx->Core.enmType));
+            return VERR_INTERNAL_ERROR;
+    }
+    IPRT_LINUX_RESTORE_EFL_ONLY_AC();
+    return VINF_SUCCESS;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeAllocPage(PPRTR0MEMOBJINTERNAL ppMem, size_t cb, bool fExecutable)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    PRTR0MEMOBJLNX pMemLnx;
+    int rc;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_PAGE, cb, PAGE_SIZE, GFP_HIGHUSER,
+                                   false /* non-contiguous */, VERR_NO_MEMORY);
+#else
+    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_PAGE, cb, PAGE_SIZE, GFP_USER,
+                                   false /* non-contiguous */, VERR_NO_MEMORY);
+#endif
+    if (RT_SUCCESS(rc))
+    {
+        rc = rtR0MemObjLinuxVMap(pMemLnx, fExecutable);
+        if (RT_SUCCESS(rc))
+        {
+            *ppMem = &pMemLnx->Core;
+            IPRT_LINUX_RESTORE_EFL_AC();
+            return rc;
+        }
+
+        rtR0MemObjLinuxFreePages(pMemLnx);
+        rtR0MemObjDelete(&pMemLnx->Core);
+    }
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeAllocLow(PPRTR0MEMOBJINTERNAL ppMem, size_t cb, bool fExecutable)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    PRTR0MEMOBJLNX pMemLnx;
+    int rc;
+
+    /* Try to avoid GFP_DMA. GFM_DMA32 was introduced with Linux 2.6.15. */
+#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
+    /* ZONE_DMA32: 0-4GB */
+    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, PAGE_SIZE, GFP_DMA32,
+                                   false /* non-contiguous */, VERR_NO_LOW_MEMORY);
+    if (RT_FAILURE(rc))
+#endif
+#ifdef RT_ARCH_AMD64
+        /* ZONE_DMA: 0-16MB */
+        rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, PAGE_SIZE, GFP_DMA,
+                                       false /* non-contiguous */, VERR_NO_LOW_MEMORY);
+#else
+# ifdef CONFIG_X86_PAE
+# endif
+        /* ZONE_NORMAL: 0-896MB */
+        rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, PAGE_SIZE, GFP_USER,
+                                       false /* non-contiguous */, VERR_NO_LOW_MEMORY);
+#endif
+    if (RT_SUCCESS(rc))
+    {
+        rc = rtR0MemObjLinuxVMap(pMemLnx, fExecutable);
+        if (RT_SUCCESS(rc))
+        {
+            *ppMem = &pMemLnx->Core;
+            IPRT_LINUX_RESTORE_EFL_AC();
+            return rc;
+        }
+
+        rtR0MemObjLinuxFreePages(pMemLnx);
+        rtR0MemObjDelete(&pMemLnx->Core);
+    }
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeAllocCont(PPRTR0MEMOBJINTERNAL ppMem, size_t cb, bool fExecutable)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    PRTR0MEMOBJLNX pMemLnx;
+    int rc;
+
+#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
+    /* ZONE_DMA32: 0-4GB */
+    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, PAGE_SIZE, GFP_DMA32,
+                                   true /* contiguous */, VERR_NO_CONT_MEMORY);
+    if (RT_FAILURE(rc))
+#endif
+#ifdef RT_ARCH_AMD64
+        /* ZONE_DMA: 0-16MB */
+        rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, PAGE_SIZE, GFP_DMA,
+                                       true /* contiguous */, VERR_NO_CONT_MEMORY);
+#else
+        /* ZONE_NORMAL (32-bit hosts): 0-896MB */
+        rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, PAGE_SIZE, GFP_USER,
+                                       true /* contiguous */, VERR_NO_CONT_MEMORY);
+#endif
+    if (RT_SUCCESS(rc))
+    {
+        rc = rtR0MemObjLinuxVMap(pMemLnx, fExecutable);
+        if (RT_SUCCESS(rc))
+        {
+#if defined(RT_STRICT) && (defined(RT_ARCH_AMD64) || defined(CONFIG_HIGHMEM64G))
+            size_t iPage = pMemLnx->cPages;
+            while (iPage-- > 0)
+                Assert(page_to_phys(pMemLnx->apPages[iPage]) < _4G);
+#endif
+            pMemLnx->Core.u.Cont.Phys = page_to_phys(pMemLnx->apPages[0]);
+            *ppMem = &pMemLnx->Core;
+            IPRT_LINUX_RESTORE_EFL_AC();
+            return rc;
+        }
+
+        rtR0MemObjLinuxFreePages(pMemLnx);
+        rtR0MemObjDelete(&pMemLnx->Core);
+    }
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+/**
+ * Worker for rtR0MemObjLinuxAllocPhysSub that tries one allocation strategy.
+ *
+ * @returns IPRT status code.
+ * @param   ppMemLnx    Where to
+ * @param   enmType     The object type.
+ * @param   cb          The size of the allocation.
+ * @param   uAlignment  The alignment of the physical memory.
+ *                      Only valid for fContiguous == true, ignored otherwise.
+ * @param   PhysHighest See rtR0MemObjNativeAllocPhys.
+ * @param   fGfp        The Linux GFP flags to use for the allocation.
+ */
+static int rtR0MemObjLinuxAllocPhysSub2(PPRTR0MEMOBJINTERNAL ppMem, RTR0MEMOBJTYPE enmType,
+                                        size_t cb, size_t uAlignment, RTHCPHYS PhysHighest, unsigned fGfp)
+{
+    PRTR0MEMOBJLNX pMemLnx;
+    int rc;
+
+    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, enmType, cb, uAlignment, fGfp,
+                                   enmType == RTR0MEMOBJTYPE_PHYS /* contiguous / non-contiguous */,
+                                   VERR_NO_PHYS_MEMORY);
+    if (RT_FAILURE(rc))
+        return rc;
+
+    /*
+     * Check the addresses if necessary. (Can be optimized a bit for PHYS.)
+     */
+    if (PhysHighest != NIL_RTHCPHYS)
+    {
+        size_t iPage = pMemLnx->cPages;
+        while (iPage-- > 0)
+            if (page_to_phys(pMemLnx->apPages[iPage]) > PhysHighest)
+            {
+                rtR0MemObjLinuxFreePages(pMemLnx);
+                rtR0MemObjDelete(&pMemLnx->Core);
+                return VERR_NO_MEMORY;
+            }
+    }
+
+    /*
+     * Complete the object.
+     */
+    if (enmType == RTR0MEMOBJTYPE_PHYS)
+    {
+        pMemLnx->Core.u.Phys.PhysBase = page_to_phys(pMemLnx->apPages[0]);
+        pMemLnx->Core.u.Phys.fAllocated = true;
+    }
+    *ppMem = &pMemLnx->Core;
+    return rc;
+}
+
+
+/**
+ * Worker for rtR0MemObjNativeAllocPhys and rtR0MemObjNativeAllocPhysNC.
+ *
+ * @returns IPRT status code.
+ * @param   ppMem       Where to store the memory object pointer on success.
+ * @param   enmType     The object type.
+ * @param   cb          The size of the allocation.
+ * @param   uAlignment  The alignment of the physical memory.
+ *                      Only valid for enmType == RTR0MEMOBJTYPE_PHYS, ignored otherwise.
+ * @param   PhysHighest See rtR0MemObjNativeAllocPhys.
+ */
+static int rtR0MemObjLinuxAllocPhysSub(PPRTR0MEMOBJINTERNAL ppMem, RTR0MEMOBJTYPE enmType,
+                                       size_t cb, size_t uAlignment, RTHCPHYS PhysHighest)
+{
+    int rc;
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * There are two clear cases and that's the <=16MB and anything-goes ones.
+     * When the physical address limit is somewhere in-between those two we'll
+     * just have to try, starting with HIGHUSER and working our way thru the
+     * different types, hoping we'll get lucky.
+     *
+     * We should probably move this physical address restriction logic up to
+     * the page alloc function as it would be more efficient there. But since
+     * we don't expect this to be a performance issue just yet it can wait.
+     */
+    if (PhysHighest == NIL_RTHCPHYS)
+        /* ZONE_HIGHMEM: the whole physical memory */
+        rc = rtR0MemObjLinuxAllocPhysSub2(ppMem, enmType, cb, uAlignment, PhysHighest, GFP_HIGHUSER);
+    else if (PhysHighest <= _1M * 16)
+        /* ZONE_DMA: 0-16MB */
+        rc = rtR0MemObjLinuxAllocPhysSub2(ppMem, enmType, cb, uAlignment, PhysHighest, GFP_DMA);
+    else
+    {
+        rc = VERR_NO_MEMORY;
+        if (RT_FAILURE(rc))
+            /* ZONE_HIGHMEM: the whole physical memory */
+            rc = rtR0MemObjLinuxAllocPhysSub2(ppMem, enmType, cb, uAlignment, PhysHighest, GFP_HIGHUSER);
+        if (RT_FAILURE(rc))
+            /* ZONE_NORMAL: 0-896MB */
+            rc = rtR0MemObjLinuxAllocPhysSub2(ppMem, enmType, cb, uAlignment, PhysHighest, GFP_USER);
+#ifdef GFP_DMA32
+        if (RT_FAILURE(rc))
+            /* ZONE_DMA32: 0-4GB */
+            rc = rtR0MemObjLinuxAllocPhysSub2(ppMem, enmType, cb, uAlignment, PhysHighest, GFP_DMA32);
+#endif
+        if (RT_FAILURE(rc))
+            /* ZONE_DMA: 0-16MB */
+            rc = rtR0MemObjLinuxAllocPhysSub2(ppMem, enmType, cb, uAlignment, PhysHighest, GFP_DMA);
+    }
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+/**
+ * Translates a kernel virtual address to a linux page structure by walking the
+ * page tables.
+ *
+ * @note    We do assume that the page tables will not change as we are walking
+ *          them.  This assumption is rather forced by the fact that I could not
+ *          immediately see any way of preventing this from happening.  So, we
+ *          take some extra care when accessing them.
+ *
+ *          Because of this, we don't want to use this function on memory where
+ *          attribute changes to nearby pages is likely to cause large pages to
+ *          be used or split up. So, don't use this for the linear mapping of
+ *          physical memory.
+ *
+ * @returns Pointer to the page structur or NULL if it could not be found.
+ * @param   pv      The kernel virtual address.
+ */
+static struct page *rtR0MemObjLinuxVirtToPage(void *pv)
+{
+    unsigned long   ulAddr = (unsigned long)pv;
+    unsigned long   pfn;
+    struct page    *pPage;
+    pte_t          *pEntry;
+    union
+    {
+        pgd_t       Global;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
+        p4d_t       Four;
+#endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
+        pud_t       Upper;
+#endif
+        pmd_t       Middle;
+        pte_t       Entry;
+    } u;
+
+    /* Should this happen in a situation this code will be called in?  And if
+     * so, can it change under our feet?  See also
+     * "Documentation/vm/active_mm.txt" in the kernel sources. */
+    if (RT_UNLIKELY(!current->active_mm))
+        return NULL;
+    u.Global = *pgd_offset(current->active_mm, ulAddr);
+    if (RT_UNLIKELY(pgd_none(u.Global)))
+        return NULL;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
+# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
+    u.Four  = *p4d_offset(&u.Global, ulAddr);
+    if (RT_UNLIKELY(p4d_none(u.Four)))
+        return NULL;
+    if (p4d_large(u.Four))
+    {
+        pPage = p4d_page(u.Four);
+        AssertReturn(pPage, NULL);
+        pfn   = page_to_pfn(pPage);      /* doing the safe way... */
+        AssertCompile(P4D_SHIFT - PAGE_SHIFT < 31);
+        pfn  += (ulAddr >> PAGE_SHIFT) & ((UINT32_C(1) << (P4D_SHIFT - PAGE_SHIFT)) - 1);
+        return pfn_to_page(pfn);
+    }
+    u.Upper = *pud_offset(&u.Four, ulAddr);
+# else /* < 4.12 */
+    u.Upper = *pud_offset(&u.Global, ulAddr);
+# endif /* < 4.12 */
+    if (RT_UNLIKELY(pud_none(u.Upper)))
+        return NULL;
+# if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
+    if (pud_large(u.Upper))
+    {
+        pPage = pud_page(u.Upper);
+        AssertReturn(pPage, NULL);
+        pfn  = page_to_pfn(pPage);      /* doing the safe way... */
+        pfn += (ulAddr >> PAGE_SHIFT) & ((UINT32_C(1) << (PUD_SHIFT - PAGE_SHIFT)) - 1);
+        return pfn_to_page(pfn);
+    }
+# endif
+    u.Middle = *pmd_offset(&u.Upper, ulAddr);
+#else  /* < 2.6.11 */
+    u.Middle = *pmd_offset(&u.Global, ulAddr);
+#endif /* < 2.6.11 */
+    if (RT_UNLIKELY(pmd_none(u.Middle)))
+        return NULL;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
+    if (pmd_large(u.Middle))
+    {
+        pPage = pmd_page(u.Middle);
+        AssertReturn(pPage, NULL);
+        pfn  = page_to_pfn(pPage);      /* doing the safe way... */
+        pfn += (ulAddr >> PAGE_SHIFT) & ((UINT32_C(1) << (PMD_SHIFT - PAGE_SHIFT)) - 1);
+        return pfn_to_page(pfn);
+    }
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 5) || defined(pte_offset_map) /* As usual, RHEL 3 had pte_offset_map earlier. */
+    pEntry = pte_offset_map(&u.Middle, ulAddr);
+#else
+    pEntry = pte_offset(&u.Middle, ulAddr);
+#endif
+    if (RT_UNLIKELY(!pEntry))
+        return NULL;
+    u.Entry = *pEntry;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 5) || defined(pte_offset_map)
+    pte_unmap(pEntry);
+#endif
+
+    if (RT_UNLIKELY(!pte_present(u.Entry)))
+        return NULL;
+    return pte_page(u.Entry);
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeAllocPhys(PPRTR0MEMOBJINTERNAL ppMem, size_t cb, RTHCPHYS PhysHighest, size_t uAlignment)
+{
+    return rtR0MemObjLinuxAllocPhysSub(ppMem, RTR0MEMOBJTYPE_PHYS, cb, uAlignment, PhysHighest);
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeAllocPhysNC(PPRTR0MEMOBJINTERNAL ppMem, size_t cb, RTHCPHYS PhysHighest)
+{
+    return rtR0MemObjLinuxAllocPhysSub(ppMem, RTR0MEMOBJTYPE_PHYS_NC, cb, PAGE_SIZE, PhysHighest);
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeEnterPhys(PPRTR0MEMOBJINTERNAL ppMem, RTHCPHYS Phys, size_t cb, uint32_t uCachePolicy)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * All we need to do here is to validate that we can use
+     * ioremap on the specified address (32/64-bit dma_addr_t).
+     */
+    PRTR0MEMOBJLNX  pMemLnx;
+    dma_addr_t      PhysAddr = Phys;
+    AssertMsgReturn(PhysAddr == Phys, ("%#llx\n", (unsigned long long)Phys), VERR_ADDRESS_TOO_BIG);
+
+    pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(sizeof(*pMemLnx), RTR0MEMOBJTYPE_PHYS, NULL, cb);
+    if (!pMemLnx)
+    {
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VERR_NO_MEMORY;
+    }
+
+    pMemLnx->Core.u.Phys.PhysBase = PhysAddr;
+    pMemLnx->Core.u.Phys.fAllocated = false;
+    pMemLnx->Core.u.Phys.uCachePolicy = uCachePolicy;
+    Assert(!pMemLnx->cPages);
+    *ppMem = &pMemLnx->Core;
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return VINF_SUCCESS;
+}
+
+/* openSUSE Leap 42.3 detection :-/ */
+#if    LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0) \
+    && LINUX_VERSION_CODE <  KERNEL_VERSION(4, 6, 0) \
+    && defined(FAULT_FLAG_REMOTE)
+# define GET_USER_PAGES_API     KERNEL_VERSION(4, 10, 0) /* no typo! */
+#else
+# define GET_USER_PAGES_API     LINUX_VERSION_CODE
+#endif
+
+DECLHIDDEN(int) rtR0MemObjNativeLockUser(PPRTR0MEMOBJINTERNAL ppMem, RTR3PTR R3Ptr, size_t cb, uint32_t fAccess, RTR0PROCESS R0Process)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    const int cPages = cb >> PAGE_SHIFT;
+    struct task_struct *pTask = rtR0ProcessToLinuxTask(R0Process);
+    struct vm_area_struct **papVMAs;
+    PRTR0MEMOBJLNX pMemLnx;
+    int             rc      = VERR_NO_MEMORY;
+    int  const      fWrite  = fAccess & RTMEM_PROT_WRITE ? 1 : 0;
+
+    /*
+     * Check for valid task and size overflows.
+     */
+    if (!pTask)
+        return VERR_NOT_SUPPORTED;
+    if (((size_t)cPages << PAGE_SHIFT) != cb)
+        return VERR_OUT_OF_RANGE;
+
+    /*
+     * Allocate the memory object and a temporary buffer for the VMAs.
+     */
+    pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(RT_UOFFSETOF_DYN(RTR0MEMOBJLNX, apPages[cPages]), RTR0MEMOBJTYPE_LOCK, (void *)R3Ptr, cb);
+    if (!pMemLnx)
+    {
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VERR_NO_MEMORY;
+    }
+
+    papVMAs = (struct vm_area_struct **)RTMemAlloc(sizeof(*papVMAs) * cPages);
+    if (papVMAs)
+    {
+        down_read(&pTask->mm->mmap_sem);
+
+        /*
+         * Get user pages.
+         */
+#if GET_USER_PAGES_API >= KERNEL_VERSION(4, 6, 0)
+        if (R0Process == RTR0ProcHandleSelf())
+            rc = get_user_pages(R3Ptr,                  /* Where from. */
+                                cPages,                 /* How many pages. */
+# if GET_USER_PAGES_API >= KERNEL_VERSION(4, 9, 0)
+                                fWrite ? FOLL_WRITE |   /* Write to memory. */
+                                         FOLL_FORCE     /* force write access. */
+                                       : 0,             /* Write to memory. */
+# else
+                                fWrite,                 /* Write to memory. */
+                                fWrite,                 /* force write access. */
+# endif
+                                &pMemLnx->apPages[0],   /* Page array. */
+                                papVMAs);               /* vmas */
+        /*
+         * Actually this should not happen at the moment as call this function
+         * only for our own process.
+         */
+        else
+            rc = get_user_pages_remote(
+                                pTask,                  /* Task for fault accounting. */
+                                pTask->mm,              /* Whose pages. */
+                                R3Ptr,                  /* Where from. */
+                                cPages,                 /* How many pages. */
+# if GET_USER_PAGES_API >= KERNEL_VERSION(4, 9, 0)
+                                fWrite ? FOLL_WRITE |   /* Write to memory. */
+                                         FOLL_FORCE     /* force write access. */
+                                       : 0,             /* Write to memory. */
+# else
+                                fWrite,                 /* Write to memory. */
+                                fWrite,                 /* force write access. */
+# endif
+                                &pMemLnx->apPages[0],   /* Page array. */
+                                papVMAs                 /* vmas */
+# if GET_USER_PAGES_API >= KERNEL_VERSION(4, 10, 0)
+                                , NULL                  /* locked */
+# endif
+                                );
+#else /* GET_USER_PAGES_API < KERNEL_VERSION(4, 6, 0) */
+            rc = get_user_pages(pTask,                  /* Task for fault accounting. */
+                                pTask->mm,              /* Whose pages. */
+                                R3Ptr,                  /* Where from. */
+                                cPages,                 /* How many pages. */
+# if GET_USER_PAGES_API >= KERNEL_VERSION(4, 9, 0)
+                                fWrite ? FOLL_WRITE |   /* Write to memory. */
+                                         FOLL_FORCE     /* force write access. */
+                                       : 0,             /* Write to memory. */
+# else
+                                fWrite,                 /* Write to memory. */
+                                fWrite,                 /* force write access. */
+# endif
+                                &pMemLnx->apPages[0],   /* Page array. */
+                                papVMAs);               /* vmas */
+#endif /* GET_USER_PAGES_API < KERNEL_VERSION(4, 6, 0) */
+        if (rc == cPages)
+        {
+            /*
+             * Flush dcache (required?), protect against fork and _really_ pin the page
+             * table entries. get_user_pages() will protect against swapping out the
+             * pages but it will NOT protect against removing page table entries. This
+             * can be achieved with
+             *   - using mlock / mmap(..., MAP_LOCKED, ...) from userland. This requires
+             *     an appropriate limit set up with setrlimit(..., RLIMIT_MEMLOCK, ...).
+             *     Usual Linux distributions support only a limited size of locked pages
+             *     (e.g. 32KB).
+             *   - setting the PageReserved bit (as we do in rtR0MemObjLinuxAllocPages()
+             *     or by
+             *   - setting the VM_LOCKED flag. This is the same as doing mlock() without
+             *     a range check.
+             */
+            /** @todo The Linux fork() protection will require more work if this API
+             * is to be used for anything but locking VM pages. */
+            while (rc-- > 0)
+            {
+                flush_dcache_page(pMemLnx->apPages[rc]);
+                papVMAs[rc]->vm_flags |= (VM_DONTCOPY | VM_LOCKED);
+            }
+
+            up_read(&pTask->mm->mmap_sem);
+
+            RTMemFree(papVMAs);
+
+            pMemLnx->Core.u.Lock.R0Process = R0Process;
+            pMemLnx->cPages = cPages;
+            Assert(!pMemLnx->fMappedToRing0);
+            *ppMem = &pMemLnx->Core;
+
+            IPRT_LINUX_RESTORE_EFL_AC();
+            return VINF_SUCCESS;
+        }
+
+        /*
+         * Failed - we need to unlock any pages that we succeeded to lock.
+         */
+        while (rc-- > 0)
+        {
+            if (!PageReserved(pMemLnx->apPages[rc]))
+                SetPageDirty(pMemLnx->apPages[rc]);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
+            put_page(pMemLnx->apPages[rc]);
+#else
+            page_cache_release(pMemLnx->apPages[rc]);
+#endif
+        }
+
+        up_read(&pTask->mm->mmap_sem);
+
+        RTMemFree(papVMAs);
+        rc = VERR_LOCK_FAILED;
+    }
+
+    rtR0MemObjDelete(&pMemLnx->Core);
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeLockKernel(PPRTR0MEMOBJINTERNAL ppMem, void *pv, size_t cb, uint32_t fAccess)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    void           *pvLast = (uint8_t *)pv + cb - 1;
+    size_t const    cPages = cb >> PAGE_SHIFT;
+    PRTR0MEMOBJLNX  pMemLnx;
+    bool            fLinearMapping;
+    int             rc;
+    uint8_t        *pbPage;
+    size_t          iPage;
+    NOREF(fAccess);
+
+    if (   !RTR0MemKernelIsValidAddr(pv)
+        || !RTR0MemKernelIsValidAddr(pv + cb))
+        return VERR_INVALID_PARAMETER;
+
+    /*
+     * The lower part of the kernel memory has a linear mapping between
+     * physical and virtual addresses. So we take a short cut here.  This is
+     * assumed to be the cleanest way to handle those addresses (and the code
+     * is well tested, though the test for determining it is not very nice).
+     * If we ever decide it isn't we can still remove it.
+     */
+#if 0
+    fLinearMapping = (unsigned long)pvLast < VMALLOC_START;
+#else
+    fLinearMapping = (unsigned long)pv     >= (unsigned long)__va(0)
+                  && (unsigned long)pvLast <  (unsigned long)high_memory;
+#endif
+
+    /*
+     * Allocate the memory object.
+     */
+    pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(RT_UOFFSETOF_DYN(RTR0MEMOBJLNX, apPages[cPages]), RTR0MEMOBJTYPE_LOCK, pv, cb);
+    if (!pMemLnx)
+    {
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VERR_NO_MEMORY;
+    }
+
+    /*
+     * Gather the pages.
+     * We ASSUME all kernel pages are non-swappable and non-movable.
+     */
+    rc     = VINF_SUCCESS;
+    pbPage = (uint8_t *)pvLast;
+    iPage  = cPages;
+    if (!fLinearMapping)
+    {
+        while (iPage-- > 0)
+        {
+            struct page *pPage = rtR0MemObjLinuxVirtToPage(pbPage);
+            if (RT_UNLIKELY(!pPage))
+            {
+                rc = VERR_LOCK_FAILED;
+                break;
+            }
+            pMemLnx->apPages[iPage] = pPage;
+            pbPage -= PAGE_SIZE;
+        }
+    }
+    else
+    {
+        while (iPage-- > 0)
+        {
+            pMemLnx->apPages[iPage] = virt_to_page(pbPage);
+            pbPage -= PAGE_SIZE;
+        }
+    }
+    if (RT_SUCCESS(rc))
+    {
+        /*
+         * Complete the memory object and return.
+         */
+        pMemLnx->Core.u.Lock.R0Process = NIL_RTR0PROCESS;
+        pMemLnx->cPages = cPages;
+        Assert(!pMemLnx->fMappedToRing0);
+        *ppMem = &pMemLnx->Core;
+
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VINF_SUCCESS;
+    }
+
+    rtR0MemObjDelete(&pMemLnx->Core);
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeReserveKernel(PPRTR0MEMOBJINTERNAL ppMem, void *pvFixed, size_t cb, size_t uAlignment)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+    IPRT_LINUX_SAVE_EFL_AC();
+    const size_t cPages = cb >> PAGE_SHIFT;
+    struct page *pDummyPage;
+    struct page **papPages;
+
+    /* check for unsupported stuff. */
+    AssertMsgReturn(pvFixed == (void *)-1, ("%p\n", pvFixed), VERR_NOT_SUPPORTED);
+    if (uAlignment > PAGE_SIZE)
+        return VERR_NOT_SUPPORTED;
+
+    /*
+     * Allocate a dummy page and create a page pointer array for vmap such that
+     * the dummy page is mapped all over the reserved area.
+     */
+    pDummyPage = alloc_page(GFP_HIGHUSER | __GFP_NOWARN);
+    if (pDummyPage)
+    {
+        papPages = RTMemAlloc(sizeof(*papPages) * cPages);
+        if (papPages)
+        {
+            void *pv;
+            size_t iPage = cPages;
+            while (iPage-- > 0)
+                papPages[iPage] = pDummyPage;
+# ifdef VM_MAP
+            pv = vmap(papPages, cPages, VM_MAP, PAGE_KERNEL_RO);
+# else
+            pv = vmap(papPages, cPages, VM_ALLOC, PAGE_KERNEL_RO);
+# endif
+            RTMemFree(papPages);
+            if (pv)
+            {
+                PRTR0MEMOBJLNX pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(sizeof(*pMemLnx), RTR0MEMOBJTYPE_RES_VIRT, pv, cb);
+                if (pMemLnx)
+                {
+                    pMemLnx->Core.u.ResVirt.R0Process = NIL_RTR0PROCESS;
+                    pMemLnx->cPages = 1;
+                    pMemLnx->apPages[0] = pDummyPage;
+                    *ppMem = &pMemLnx->Core;
+                    IPRT_LINUX_RESTORE_EFL_AC();
+                    return VINF_SUCCESS;
+                }
+                vunmap(pv);
+            }
+        }
+        __free_page(pDummyPage);
+    }
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return VERR_NO_MEMORY;
+
+#else   /* < 2.4.22 */
+    /*
+     * Could probably use ioremap here, but the caller is in a better position than us
+     * to select some safe physical memory.
+     */
+    return VERR_NOT_SUPPORTED;
+#endif
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeReserveUser(PPRTR0MEMOBJINTERNAL ppMem, RTR3PTR R3PtrFixed, size_t cb, size_t uAlignment, RTR0PROCESS R0Process)
+{
+    IPRT_LINUX_SAVE_EFL_AC();
+    PRTR0MEMOBJLNX      pMemLnx;
+    void               *pv;
+    struct task_struct *pTask = rtR0ProcessToLinuxTask(R0Process);
+    if (!pTask)
+        return VERR_NOT_SUPPORTED;
+
+    /*
+     * Check that the specified alignment is supported.
+     */
+    if (uAlignment > PAGE_SIZE)
+        return VERR_NOT_SUPPORTED;
+
+    /*
+     * Let rtR0MemObjLinuxDoMmap do the difficult bits.
+     */
+    pv = rtR0MemObjLinuxDoMmap(R3PtrFixed, cb, uAlignment, pTask, RTMEM_PROT_NONE);
+    if (pv == (void *)-1)
+    {
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VERR_NO_MEMORY;
+    }
+
+    pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(sizeof(*pMemLnx), RTR0MEMOBJTYPE_RES_VIRT, pv, cb);
+    if (!pMemLnx)
+    {
+        rtR0MemObjLinuxDoMunmap(pv, cb, pTask);
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VERR_NO_MEMORY;
+    }
+
+    pMemLnx->Core.u.ResVirt.R0Process = R0Process;
+    *ppMem = &pMemLnx->Core;
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return VINF_SUCCESS;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeMapKernel(PPRTR0MEMOBJINTERNAL ppMem, RTR0MEMOBJ pMemToMap,
+                                          void *pvFixed, size_t uAlignment,
+                                          unsigned fProt, size_t offSub, size_t cbSub)
+{
+    int rc = VERR_NO_MEMORY;
+    PRTR0MEMOBJLNX pMemLnxToMap = (PRTR0MEMOBJLNX)pMemToMap;
+    PRTR0MEMOBJLNX pMemLnx;
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /* Fail if requested to do something we can't. */
+    AssertMsgReturn(!offSub && !cbSub, ("%#x %#x\n", offSub, cbSub), VERR_NOT_SUPPORTED);
+    AssertMsgReturn(pvFixed == (void *)-1, ("%p\n", pvFixed), VERR_NOT_SUPPORTED);
+    if (uAlignment > PAGE_SIZE)
+        return VERR_NOT_SUPPORTED;
+
+    /*
+     * Create the IPRT memory object.
+     */
+    pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(sizeof(*pMemLnx), RTR0MEMOBJTYPE_MAPPING, NULL, pMemLnxToMap->Core.cb);
+    if (pMemLnx)
+    {
+        if (pMemLnxToMap->cPages)
+        {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
+            /*
+             * Use vmap - 2.4.22 and later.
+             */
+            pgprot_t fPg = rtR0MemObjLinuxConvertProt(fProt, true /* kernel */);
+# ifdef VM_MAP
+            pMemLnx->Core.pv = vmap(&pMemLnxToMap->apPages[0], pMemLnxToMap->cPages, VM_MAP, fPg);
+# else
+            pMemLnx->Core.pv = vmap(&pMemLnxToMap->apPages[0], pMemLnxToMap->cPages, VM_ALLOC, fPg);
+# endif
+            if (pMemLnx->Core.pv)
+            {
+                pMemLnx->fMappedToRing0 = true;
+                rc = VINF_SUCCESS;
+            }
+            else
+                rc = VERR_MAP_FAILED;
+
+#else   /* < 2.4.22 */
+            /*
+             * Only option here is to share mappings if possible and forget about fProt.
+             */
+            if (rtR0MemObjIsRing3(pMemToMap))
+                rc = VERR_NOT_SUPPORTED;
+            else
+            {
+                rc = VINF_SUCCESS;
+                if (!pMemLnxToMap->Core.pv)
+                    rc = rtR0MemObjLinuxVMap(pMemLnxToMap, !!(fProt & RTMEM_PROT_EXEC));
+                if (RT_SUCCESS(rc))
+                {
+                    Assert(pMemLnxToMap->Core.pv);
+                    pMemLnx->Core.pv = pMemLnxToMap->Core.pv;
+                }
+            }
+#endif
+        }
+        else
+        {
+            /*
+             * MMIO / physical memory.
+             */
+            Assert(pMemLnxToMap->Core.enmType == RTR0MEMOBJTYPE_PHYS && !pMemLnxToMap->Core.u.Phys.fAllocated);
+            pMemLnx->Core.pv = pMemLnxToMap->Core.u.Phys.uCachePolicy == RTMEM_CACHE_POLICY_MMIO
+                             ? ioremap_nocache(pMemLnxToMap->Core.u.Phys.PhysBase, pMemLnxToMap->Core.cb)
+                             : ioremap(pMemLnxToMap->Core.u.Phys.PhysBase, pMemLnxToMap->Core.cb);
+            if (pMemLnx->Core.pv)
+            {
+                /** @todo fix protection. */
+                rc = VINF_SUCCESS;
+            }
+        }
+        if (RT_SUCCESS(rc))
+        {
+            pMemLnx->Core.u.Mapping.R0Process = NIL_RTR0PROCESS;
+            *ppMem = &pMemLnx->Core;
+            IPRT_LINUX_RESTORE_EFL_AC();
+            return VINF_SUCCESS;
+        }
+        rtR0MemObjDelete(&pMemLnx->Core);
+    }
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+#ifdef VBOX_USE_PAE_HACK
+/**
+ * Replace the PFN of a PTE with the address of the actual page.
+ *
+ * The caller maps a reserved dummy page at the address with the desired access
+ * and flags.
+ *
+ * This hack is required for older Linux kernels which don't provide
+ * remap_pfn_range().
+ *
+ * @returns 0 on success, -ENOMEM on failure.
+ * @param   mm          The memory context.
+ * @param   ulAddr      The mapping address.
+ * @param   Phys        The physical address of the page to map.
+ */
+static int rtR0MemObjLinuxFixPte(struct mm_struct *mm, unsigned long ulAddr, RTHCPHYS Phys)
+{
+    int rc = -ENOMEM;
+    pgd_t *pgd;
+
+    spin_lock(&mm->page_table_lock);
+
+    pgd = pgd_offset(mm, ulAddr);
+    if (!pgd_none(*pgd) && !pgd_bad(*pgd))
+    {
+        pmd_t *pmd = pmd_offset(pgd, ulAddr);
+        if (!pmd_none(*pmd))
+        {
+            pte_t *ptep = pte_offset_map(pmd, ulAddr);
+            if (ptep)
+            {
+                pte_t pte = *ptep;
+                pte.pte_high &= 0xfff00000;
+                pte.pte_high |= ((Phys >> 32) & 0x000fffff);
+                pte.pte_low  &= 0x00000fff;
+                pte.pte_low  |= (Phys & 0xfffff000);
+                set_pte(ptep, pte);
+                pte_unmap(ptep);
+                rc = 0;
+            }
+        }
+    }
+
+    spin_unlock(&mm->page_table_lock);
+    return rc;
+}
+#endif /* VBOX_USE_PAE_HACK */
+
+
+DECLHIDDEN(int) rtR0MemObjNativeMapUser(PPRTR0MEMOBJINTERNAL ppMem, RTR0MEMOBJ pMemToMap, RTR3PTR R3PtrFixed,
+                                        size_t uAlignment, unsigned fProt, RTR0PROCESS R0Process)
+{
+    struct task_struct *pTask        = rtR0ProcessToLinuxTask(R0Process);
+    PRTR0MEMOBJLNX      pMemLnxToMap = (PRTR0MEMOBJLNX)pMemToMap;
+    int                 rc           = VERR_NO_MEMORY;
+    PRTR0MEMOBJLNX      pMemLnx;
+#ifdef VBOX_USE_PAE_HACK
+    struct page        *pDummyPage;
+    RTHCPHYS            DummyPhys;
+#endif
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * Check for restrictions.
+     */
+    if (!pTask)
+        return VERR_NOT_SUPPORTED;
+    if (uAlignment > PAGE_SIZE)
+        return VERR_NOT_SUPPORTED;
+
+#ifdef VBOX_USE_PAE_HACK
+    /*
+     * Allocate a dummy page for use when mapping the memory.
+     */
+    pDummyPage = alloc_page(GFP_USER | __GFP_NOWARN);
+    if (!pDummyPage)
+    {
+        IPRT_LINUX_RESTORE_EFL_AC();
+        return VERR_NO_MEMORY;
+    }
+    SetPageReserved(pDummyPage);
+    DummyPhys = page_to_phys(pDummyPage);
+#endif
+
+    /*
+     * Create the IPRT memory object.
+     */
+    pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(sizeof(*pMemLnx), RTR0MEMOBJTYPE_MAPPING, NULL, pMemLnxToMap->Core.cb);
+    if (pMemLnx)
+    {
+        /*
+         * Allocate user space mapping.
+         */
+        void *pv;
+        pv = rtR0MemObjLinuxDoMmap(R3PtrFixed, pMemLnxToMap->Core.cb, uAlignment, pTask, fProt);
+        if (pv != (void *)-1)
+        {
+            /*
+             * Map page by page into the mmap area.
+             * This is generic, paranoid and not very efficient.
+             */
+            pgprot_t        fPg = rtR0MemObjLinuxConvertProt(fProt, false /* user */);
+            unsigned long   ulAddrCur = (unsigned long)pv;
+            const size_t    cPages = pMemLnxToMap->Core.cb >> PAGE_SHIFT;
+            size_t          iPage;
+
+            down_write(&pTask->mm->mmap_sem);
+
+            rc = VINF_SUCCESS;
+            if (pMemLnxToMap->cPages)
+            {
+                for (iPage = 0; iPage < cPages; iPage++, ulAddrCur += PAGE_SIZE)
+                {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 11)
+                    RTHCPHYS Phys = page_to_phys(pMemLnxToMap->apPages[iPage]);
+#endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) || defined(HAVE_26_STYLE_REMAP_PAGE_RANGE)
+                    struct vm_area_struct *vma = find_vma(pTask->mm, ulAddrCur); /* this is probably the same for all the pages... */
+                    AssertBreakStmt(vma, rc = VERR_INTERNAL_ERROR);
+#endif
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0) && defined(RT_ARCH_X86)
+                    /* remap_page_range() limitation on x86 */
+                    AssertBreakStmt(Phys < _4G, rc = VERR_NO_MEMORY);
+#endif
+
+#if   defined(VBOX_USE_INSERT_PAGE) && LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22)
+                    rc = vm_insert_page(vma, ulAddrCur, pMemLnxToMap->apPages[iPage]);
+                    /* Thes flags help making 100% sure some bad stuff wont happen (swap, core, ++).
+                     * See remap_pfn_range() in mm/memory.c */
+#if    LINUX_VERSION_CODE >= KERNEL_VERSION(3, 7, 0)
+                    vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+#else
+                    vma->vm_flags |= VM_RESERVED;
+#endif
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
+                    rc = remap_pfn_range(vma, ulAddrCur, page_to_pfn(pMemLnxToMap->apPages[iPage]), PAGE_SIZE, fPg);
+#elif defined(VBOX_USE_PAE_HACK)
+                    rc = remap_page_range(vma, ulAddrCur, DummyPhys, PAGE_SIZE, fPg);
+                    if (!rc)
+                        rc = rtR0MemObjLinuxFixPte(pTask->mm, ulAddrCur, Phys);
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) || defined(HAVE_26_STYLE_REMAP_PAGE_RANGE)
+                    rc = remap_page_range(vma, ulAddrCur, Phys, PAGE_SIZE, fPg);
+#else /* 2.4 */
+                    rc = remap_page_range(ulAddrCur, Phys, PAGE_SIZE, fPg);
+#endif
+                    if (rc)
+                    {
+                        rc = VERR_NO_MEMORY;
+                        break;
+                    }
+                }
+            }
+            else
+            {
+                RTHCPHYS Phys;
+                if (pMemLnxToMap->Core.enmType == RTR0MEMOBJTYPE_PHYS)
+                    Phys = pMemLnxToMap->Core.u.Phys.PhysBase;
+                else if (pMemLnxToMap->Core.enmType == RTR0MEMOBJTYPE_CONT)
+                    Phys = pMemLnxToMap->Core.u.Cont.Phys;
+                else
+                {
+                    AssertMsgFailed(("%d\n", pMemLnxToMap->Core.enmType));
+                    Phys = NIL_RTHCPHYS;
+                }
+                if (Phys != NIL_RTHCPHYS)
+                {
+                    for (iPage = 0; iPage < cPages; iPage++, ulAddrCur += PAGE_SIZE, Phys += PAGE_SIZE)
+                    {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) || defined(HAVE_26_STYLE_REMAP_PAGE_RANGE)
+                        struct vm_area_struct *vma = find_vma(pTask->mm, ulAddrCur); /* this is probably the same for all the pages... */
+                        AssertBreakStmt(vma, rc = VERR_INTERNAL_ERROR);
+#endif
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0) && defined(RT_ARCH_X86)
+                        /* remap_page_range() limitation on x86 */
+                        AssertBreakStmt(Phys < _4G, rc = VERR_NO_MEMORY);
+#endif
+
+#if   LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
+                        rc = remap_pfn_range(vma, ulAddrCur, Phys, PAGE_SIZE, fPg);
+#elif defined(VBOX_USE_PAE_HACK)
+                        rc = remap_page_range(vma, ulAddrCur, DummyPhys, PAGE_SIZE, fPg);
+                        if (!rc)
+                            rc = rtR0MemObjLinuxFixPte(pTask->mm, ulAddrCur, Phys);
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) || defined(HAVE_26_STYLE_REMAP_PAGE_RANGE)
+                        rc = remap_page_range(vma, ulAddrCur, Phys, PAGE_SIZE, fPg);
+#else /* 2.4 */
+                        rc = remap_page_range(ulAddrCur, Phys, PAGE_SIZE, fPg);
+#endif
+                        if (rc)
+                        {
+                            rc = VERR_NO_MEMORY;
+                            break;
+                        }
+                    }
+                }
+            }
+
+#ifdef CONFIG_NUMA_BALANCING
+# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 13, 0)
+#  ifdef RHEL_RELEASE_CODE
+#   if RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(7, 0)
+#    define VBOX_NUMA_HACK_OLD
+#   endif
+#  endif
+# endif
+            if (RT_SUCCESS(rc))
+            {
+                /** @todo Ugly hack! But right now we have no other means to
+                 *        disable automatic NUMA page balancing. */
+# ifdef RT_OS_X86
+#  ifdef VBOX_NUMA_HACK_OLD
+                pTask->mm->numa_next_reset = jiffies + 0x7fffffffUL;
+#  endif
+                pTask->mm->numa_next_scan  = jiffies + 0x7fffffffUL;
+# else
+#  ifdef VBOX_NUMA_HACK_OLD
+                pTask->mm->numa_next_reset = jiffies + 0x7fffffffffffffffUL;
+#  endif
+                pTask->mm->numa_next_scan  = jiffies + 0x7fffffffffffffffUL;
+# endif
+            }
+#endif /* CONFIG_NUMA_BALANCING */
+
+            up_write(&pTask->mm->mmap_sem);
+
+            if (RT_SUCCESS(rc))
+            {
+#ifdef VBOX_USE_PAE_HACK
+                __free_page(pDummyPage);
+#endif
+                pMemLnx->Core.pv = pv;
+                pMemLnx->Core.u.Mapping.R0Process = R0Process;
+                *ppMem = &pMemLnx->Core;
+                IPRT_LINUX_RESTORE_EFL_AC();
+                return VINF_SUCCESS;
+            }
+
+            /*
+             * Bail out.
+             */
+            rtR0MemObjLinuxDoMunmap(pv, pMemLnxToMap->Core.cb, pTask);
+        }
+        rtR0MemObjDelete(&pMemLnx->Core);
+    }
+#ifdef VBOX_USE_PAE_HACK
+    __free_page(pDummyPage);
+#endif
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+
+
+DECLHIDDEN(int) rtR0MemObjNativeProtect(PRTR0MEMOBJINTERNAL pMem, size_t offSub, size_t cbSub, uint32_t fProt)
+{
+    NOREF(pMem);
+    NOREF(offSub);
+    NOREF(cbSub);
+    NOREF(fProt);
+    return VERR_NOT_SUPPORTED;
+}
+
+
+DECLHIDDEN(RTHCPHYS) rtR0MemObjNativeGetPagePhysAddr(PRTR0MEMOBJINTERNAL pMem, size_t iPage)
+{
+    PRTR0MEMOBJLNX  pMemLnx = (PRTR0MEMOBJLNX)pMem;
+
+    if (pMemLnx->cPages)
+        return page_to_phys(pMemLnx->apPages[iPage]);
+
+    switch (pMemLnx->Core.enmType)
+    {
+        case RTR0MEMOBJTYPE_CONT:
+            return pMemLnx->Core.u.Cont.Phys     + (iPage << PAGE_SHIFT);
+
+        case RTR0MEMOBJTYPE_PHYS:
+            return pMemLnx->Core.u.Phys.PhysBase + (iPage << PAGE_SHIFT);
+
+            /* the parent knows */
+        case RTR0MEMOBJTYPE_MAPPING:
+            return rtR0MemObjNativeGetPagePhysAddr(pMemLnx->Core.uRel.Child.pParent, iPage);
+
+            /* cPages > 0 */
+        case RTR0MEMOBJTYPE_LOW:
+        case RTR0MEMOBJTYPE_LOCK:
+        case RTR0MEMOBJTYPE_PHYS_NC:
+        case RTR0MEMOBJTYPE_PAGE:
+        default:
+            AssertMsgFailed(("%d\n", pMemLnx->Core.enmType));
+            /* fall thru */
+
+        case RTR0MEMOBJTYPE_RES_VIRT:
+            return NIL_RTHCPHYS;
+    }
+}
+