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 VOID
  21 NTAPI
  22 INIT_FUNCTION
  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 VOID
  40 NTAPI
  41 INIT_FUNCTION
  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,
  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 INIT_FUNCTION
  89 VdmpInitialize(PVOID ControlData)
  90 {
  91     OBJECT_ATTRIBUTES ObjectAttributes;
  92     UNICODE_STRING PhysMemName = RTL_CONSTANT_STRING(L"\\Device\\PhysicalMemory");
  93     NTSTATUS Status;
  94     HANDLE PhysMemHandle;
  95     PVOID BaseAddress;
  96     volatile PVOID NullAddress = NULL;
  97     LARGE_INTEGER Offset;
  98     ULONG ViewSize;
  99
 100     /* Open the physical memory section */
 101     InitializeObjectAttributes(&ObjectAttributes,
 102                                &PhysMemName,
 103                                0,
 104                                NULL,
 105                                NULL);
 106     Status = ZwOpenSection(&PhysMemHandle,
 107                            SECTION_ALL_ACCESS,
 108                            &ObjectAttributes);
 109     if (!NT_SUCCESS(Status))
 110     {
 111         DPRINT1("Couldn't open \\Device\\PhysicalMemory\n");
 112         return Status;
 113     }
 114
 115     /* Map the BIOS and device registers into the address space */
 116     Offset.QuadPart = 0;
 117     ViewSize = PAGE_SIZE;
 118     BaseAddress = 0;
 119     Status = ZwMapViewOfSection(PhysMemHandle,
 120                                 NtCurrentProcess(),
 121                                 &BaseAddress,
 122                                 0,
 123                                 ViewSize,
 124                                 &Offset,
 125                                 &ViewSize,
 126                                 ViewUnmap,
 127                                 0,
 128                                 PAGE_READWRITE);
 129     if (!NT_SUCCESS(Status))
 130     {
 131         DPRINT1("Couldn't map physical memory (%x)\n", Status);
 132         ZwClose(PhysMemHandle);
 133         return Status;
 134     }
 135
 136     /* Enter SEH */
 137     _SEH2_TRY
 138     {
 139         /* Copy the first physical page into the first virtual page */
 140         RtlMoveMemory(NullAddress, BaseAddress, ViewSize);
 141     }
 142     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 143     {
 144         /* Fail */
 145         DPRINT1("Couldn't copy first page (%x)\n", Status);
 146         ZwClose(PhysMemHandle);
 147         ZwUnmapViewOfSection(NtCurrentProcess(), BaseAddress);
 148         _SEH2_YIELD(return _SEH2_GetExceptionCode());
 149     }
 150     _SEH2_END;
 151
 152     /* Close physical memory section handle */
 153     ZwClose(PhysMemHandle);
 154
 155     /* Unmap the section */
 156     Status = ZwUnmapViewOfSection(NtCurrentProcess(), BaseAddress);
 157
 158     if (!NT_SUCCESS(Status))
 159     {
 160         DPRINT1("Couldn't unmap the section (%x)\n", Status);
 161         return Status;
 162     }
 163
 164     return STATUS_SUCCESS;
 165 }
 166
 167 /* PUBLIC FUNCTIONS **********************************************************/
 168
 169 /*
 170  * @implemented
 171  */
 172 NTSTATUS
 173 NTAPI
 174 NtVdmControl(IN ULONG ControlCode,
 175              IN PVOID ControlData)
 176 {
 177     NTSTATUS Status;
 178     PAGED_CODE();
 179
 180     /* Check which control code this is */
 181     switch (ControlCode)
 182     {
 183         /* VDM Execution start */
 184         case VdmStartExecution:
 185
 186             /* Call the sub-function */
 187             Status = VdmpStartExecution();
 188             break;
 189
 190         case VdmInitialize:
 191
 192             /* Call the init sub-function */
 193             Status = VdmpInitialize(ControlData);
 194             break;
 195
 196         default:
 197
 198             /* Unsupported */
 199             DPRINT1("Unknown VDM call: %lx\n", ControlCode);
 200             Status = STATUS_INVALID_PARAMETER;
 201     }
 202
 203     /* Return the status */
 204     return Status;
 205 }