summaryrefslogtreecommitdiffstats
path: root/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-PagingInitRootForPP.c
blob: cea59f3a1b670337a15f8ddc5500943c1c5cb7c3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* $Id: bs3-cmn-PagingInitRootForPP.c $ */
/** @file
 * BS3Kit - Bs3PagingInitRootForPP
 */

/*
 * Copyright (C) 2007-2019 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 "bs3kit-template-header.h"
#include "bs3-cmn-paging.h"
#include "bs3-cmn-memory.h" /* bad bird */
#include <iprt/param.h>


/**
 * Creates page tables for a section of the page directory.
 *
 * @returns VINF_SUCCESS or VERR_NO_MEMORY.
 * @param   pPgDir              The page directory.
 * @param   iFirst              The first PD entry.
 * @param   cEntries            How many PD entries to create pages tables for.
 */
static int Bs3PagingInitPageTablesForPgDir(X86PD BS3_FAR *pPgDir, unsigned iFirst, unsigned cEntries)
{
    uint32_t uCurPhys = (uint32_t)iFirst << X86_PD_SHIFT;

    while (cEntries--)
    {
        X86PT BS3_FAR *pPt = (X86PT BS3_FAR *)Bs3MemAlloc(BS3MEMKIND_TILED, _4K);
        if (pPt)
        {
            unsigned j = 0;
            for (j = 0; j < RT_ELEMENTS(pPt->a); j++, uCurPhys += PAGE_SIZE)
            {
                pPt->a[j].u  = uCurPhys;
                pPt->a[j].u |= X86_PTE_P | X86_PTE_RW | X86_PTE_US | X86_PTE_A | X86_PTE_D;
            }
            pPgDir->a[iFirst].u = Bs3SelPtrToFlat(pPt);
            pPgDir->a[iFirst].u |= X86_PDE_P | X86_PDE_RW | X86_PDE_US | X86_PDE_A;
            iFirst++;
        }
        else
            return VERR_NO_MEMORY;
    }
    return VINF_SUCCESS;
}


#undef Bs3PagingInitRootForPP
BS3_CMN_DEF(int, Bs3PagingInitRootForPP,(void))
{
    X86PD BS3_FAR *pPgDir;

    BS3_ASSERT(g_PhysPagingRootPP == UINT32_MAX);


    /*
     * By default we do a identity mapping of the entire address space
     * using 4 GB pages.  So, we only really need one page directory,
     * that's all.
     *
     * ASSUMES page size extension available, i.e. pentium+.
     */
    pPgDir = (X86PD BS3_FAR *)Bs3MemAllocZ(BS3MEMKIND_TILED, _4K);
    if (pPgDir)
    {
        BS3_XPTR_AUTO(X86PD, XptrPgDir);
        unsigned i;
        int rc = VINF_SUCCESS;

        if (g_uBs3CpuDetected & BS3CPU_F_PSE)
        {
            for (i = 0; i < RT_ELEMENTS(pPgDir->a); i++)
            {
                pPgDir->a[i].u = (uint32_t)i << X86_PD_SHIFT;
                pPgDir->a[i].u |= X86_PDE4M_P | X86_PDE4M_RW | X86_PDE4M_US | X86_PDE4M_PS | X86_PDE4M_A | X86_PDE4M_D;
            }

            /* Free up 4 consequtive entries for raw-mode hypervisor code. */
            if (1) /** @todo detect raw-mode and only do this then. */
                for (i = 0; i < 4; i++)
                    pPgDir->a[i + (UINT32_C(0xc0000000) >> X86_PD_SHIFT)].b.u1Present = 0;
        }
        else
        {
            /*
             * This requires 4MB of page tables if we map everything.
             * So, we check how much memory we have available and make sure we
             * don't use all of it for page tables.
             */
            unsigned cMax = RT_ELEMENTS(pPgDir->a);
            uint32_t cFreePages = g_Bs3Mem4KUpperTiled.Core.cFreeChunks + g_Bs3Mem4KLow.Core.cFreeChunks;
            if (cFreePages >= cMax + 128)
                Bs3PagingInitPageTablesForPgDir(pPgDir, 0, cMax);
            else
            {
                unsigned cTop;
                if (cMax >= 256 /*1MB*/)
                {
                    cMax = cFreePages - 128;
                    cTop = 32;
                }
                else if (cMax >= 128)
                {
                    cMax = cFreePages - 48;
                    cTop = 16;
                }
                else
                {
                    cMax = cFreePages - 16;
                    cTop = RT_MIN(16, cMax / 4);
                }
                Bs3TestPrintf("Bs3PagingInitRootForPP: Warning! insufficient memory for mapping all 4GB!\n"
                              "    Will only map 0x00000000-%#010RX32 and %#010RX32-0xffffffff.\n",
                              (uint32_t)(cMax - cTop) << PAGE_SHIFT, UINT32_MAX - ((uint32_t)cTop << PAGE_SHIFT) + 1);
                rc = Bs3PagingInitPageTablesForPgDir(pPgDir, 0, cMax - cTop);
                if (RT_SUCCESS(rc))
                    rc = Bs3PagingInitPageTablesForPgDir(pPgDir, RT_ELEMENTS(pPgDir->a) - cTop, cTop);
            }
        }

        BS3_XPTR_SET(X86PD, XptrPgDir, pPgDir);
        g_PhysPagingRootPP = BS3_XPTR_GET_FLAT(X86PD, XptrPgDir);
        return rc;
    }

    Bs3Printf("Bs3PagingInitRootForPP: No memory!\n");
    BS3_ASSERT(false);
    return VERR_NO_MEMORY;
}