ntoskrnl/vdm/vdmmain.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         GPL - See COPYING in the top level directory
   4  * FILE:            ntoskrnl/vdm/vdmmain.c
   5  * PURPOSE:         VDM Support Services
   6  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7  *                  Aleksey Bragin (aleksey@reactos.org)
   8  */
   9
  10 /* INCLUDES ******************************************************************/
  11
  12 #include <ntoskrnl.h>
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16 /* GLOBALS *******************************************************************/
  17
  18 /* PRIVATE FUNCTIONS *********************************************************/
  19
  20 INIT_FUNCTION
  21 VOID
  22 NTAPI
  23 Ki386VdmEnablePentiumExtentions(IN BOOLEAN Enable)
  24 {
  25     ULONG EFlags, Cr4;
  26
  27     /* Save interrupt state and disable them */
  28     EFlags = __readeflags();
  29     _disable();
  30
  31     /* Enable or disable VME as required */
  32     Cr4 = __readcr4();
  33     __writecr4(Enable ? Cr4 | CR4_VME : Cr4 & ~CR4_VME);
  34
  35     /* Restore interrupt state */
  36     __writeeflags(EFlags);
  37 }
  38
  39 INIT_FUNCTION
  40 VOID
  41 NTAPI
  42 KeI386VdmInitialize(VOID)
  43 {
  44     NTSTATUS Status;
  45     OBJECT_ATTRIBUTES ObjectAttributes;
  46     HANDLE RegHandle;
  47     UNICODE_STRING Name;
  48     UCHAR KeyValueInfo[sizeof(KEY_VALUE_BASIC_INFORMATION) + 30];
  49     ULONG ReturnLength;
  50
  51     /* Make sure that there is a WOW key */
  52     RtlInitUnicodeString(&Name,
  53                          L"\\Registry\\Machine\\System\\CurrentControlSet\\"
  54                          L"Control\\Wow");
  55     InitializeObjectAttributes(&ObjectAttributes,
  56                                &Name,
  57                                OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE,
  58                                NULL,
  59                                NULL);
  60     Status = ZwOpenKey(&RegHandle, KEY_READ, &ObjectAttributes);
  61     if (!NT_SUCCESS(Status)) return;
  62
  63     /* Check if VME is enabled */
  64     RtlInitUnicodeString(&Name, L"DisableVme");
  65     Status = ZwQueryValueKey(RegHandle,
  66                              &Name,
  67                              KeyValueBasicInformation,
  68                              &KeyValueInfo,
  69                              sizeof(KeyValueInfo),
  70                              &ReturnLength);
  71     if (!NT_SUCCESS(Status))
  72     {
  73         /* Not present, so check if the CPU supports VME */
  74         if (KeGetPcr()->Prcb->FeatureBits & KF_V86_VIS)
  75         {
  76             /* Enable them. FIXME: Use IPI */
  77             Ki386VdmEnablePentiumExtentions(TRUE);
  78             KeI386VirtualIntExtensions = TRUE;
  79         }
  80     }
  81
  82     /* Close the key */
  83     ZwClose(RegHandle);
  84 }
  85
  86 NTSTATUS
  87 NTAPI
  88 VdmpInitialize(PVOID ControlData)
  89 {
  90     OBJECT_ATTRIBUTES ObjectAttributes;
  91     UNICODE_STRING PhysMemName = RTL_CONSTANT_STRING(L"\\Device\\PhysicalMemory");
  92     NTSTATUS Status;
  93     HANDLE PhysMemHandle;
  94     PVOID BaseAddress;
  95     volatile PVOID NullAddress = NULL;
  96     LARGE_INTEGER Offset;
  97     ULONG ViewSize;
  98
  99     /* Open the physical memory section */
 100     InitializeObjectAttributes(&ObjectAttributes,
 101                                &PhysMemName,
 102                                OBJ_KERNEL_HANDLE,
 103                                NULL,
 104                                NULL);
 105     Status = ZwOpenSection(&PhysMemHandle,
 106                            SECTION_ALL_ACCESS,
 107                            &ObjectAttributes);
 108     if (!NT_SUCCESS(Status))
 109     {
 110         DPRINT1("Couldn't open \\Device\\PhysicalMemory\n");
 111         return Status;
 112     }
 113
 114     /* Map the BIOS and device registers into the address space */
 115     Offset.QuadPart = 0;
 116     ViewSize = PAGE_SIZE;
 117     BaseAddress = 0;
 118     Status = ZwMapViewOfSection(PhysMemHandle,
 119                                 NtCurrentProcess(),
 120                                 &BaseAddress,
 121                                 0,
 122                                 ViewSize,
 123                                 &Offset,
 124                                 &ViewSize,
 125                                 ViewUnmap,
 126                                 0,
 127                                 PAGE_READWRITE);
 128     if (!NT_SUCCESS(Status))
 129     {
 130         DPRINT1("Couldn't map physical memory (%x)\n", Status);
 131         ZwClose(PhysMemHandle);
 132         return Status;
 133     }
 134
 135     /* Enter SEH */
 136     _SEH2_TRY
 137     {
 138         /* Copy the first physical page into the first virtual page */
 139         RtlMoveMemory(NullAddress, BaseAddress, ViewSize);
 140     }
 141     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 142     {
 143         /* Fail */
 144         DPRINT1("Couldn't copy first page (%x)\n", Status);
 145         ZwClose(PhysMemHandle);
 146         ZwUnmapViewOfSection(NtCurrentProcess(), BaseAddress);
 147         _SEH2_YIELD(return _SEH2_GetExceptionCode());
 148     }
 149     _SEH2_END;
 150
 151     /* Close physical memory section handle */
 152     ZwClose(PhysMemHandle);
 153
 154     /* Unmap the section */
 155     Status = ZwUnmapViewOfSection(NtCurrentProcess(), BaseAddress);
 156
 157     if (!NT_SUCCESS(Status))
 158     {
 159         DPRINT1("Couldn't unmap the section (%x)\n", Status);
 160         return Status;
 161     }
 162
 163     return STATUS_SUCCESS;
 164 }
 165
 166 /* PUBLIC FUNCTIONS **********************************************************/
 167
 168 /*
 169  * @implemented
 170  */
 171 NTSTATUS
 172 NTAPI
 173 NtVdmControl(IN ULONG ControlCode,
 174              IN PVOID ControlData)
 175 {
 176     NTSTATUS Status;
 177     PAGED_CODE();
 178
 179     /* Check which control code this is */
 180     switch (ControlCode)
 181     {
 182         /* VDM Execution start */
 183         case VdmStartExecution:
 184
 185             /* Call the sub-function */
 186             Status = VdmpStartExecution();
 187             break;
 188
 189         case VdmInitialize:
 190
 191             /* Call the init sub-function */
 192             Status = VdmpInitialize(ControlData);
 193             break;
 194
 195         default:
 196
 197             /* Unsupported */
 198             DPRINT1("Unknown VDM call: %lx\n", ControlCode);
 199             Status = STATUS_INVALID_PARAMETER;
 200     }
 201
 202     /* Return the status */
 203     return Status;
 204 }