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
  19 /* PRIVATE FUNCTIONS *********************************************************/
  20
  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 VOID
  40 NTAPI
  41 KeI386VdmInitialize(VOID)
  42 {
  43     NTSTATUS Status;
  44     OBJECT_ATTRIBUTES ObjectAttributes;
  45     HANDLE RegHandle;
  46     UNICODE_STRING Name;
  47     UCHAR KeyValueInfo[sizeof(KEY_VALUE_BASIC_INFORMATION) + 30];
  48     ULONG ReturnLength;
  49
  50     /* Make sure that there is a WOW key */
  51     RtlInitUnicodeString(&Name,
  52                          L"\\Registry\\Machine\\System\\CurrentControlSet\\"
  53                          L"Control\\Wow");
  54     InitializeObjectAttributes(&ObjectAttributes,
  55                                &Name,
  56                                OBJ_CASE_INSENSITIVE,
  57                                NULL,
  58                                NULL);
  59     Status = ZwOpenKey(&RegHandle, KEY_READ, &ObjectAttributes);
  60     if (!NT_SUCCESS(Status)) return;
  61
  62     /* Check if VME is enabled */
  63     RtlInitUnicodeString(&Name, L"DisableVme");
  64     Status = ZwQueryValueKey(RegHandle,
  65                              &Name,
  66                              KeyValueBasicInformation,
  67                              &KeyValueInfo,
  68                              sizeof(KeyValueInfo),
  69                              &ReturnLength);
  70     if (!NT_SUCCESS(Status))
  71     {
  72         /* Not present, so check if the CPU supports VME */
  73         if (KeGetPcr()->Prcb->FeatureBits & KF_V86_VIS)
  74         {
  75             /* Enable them. FIXME: Use IPI */
  76             Ki386VdmEnablePentiumExtentions(TRUE);
  77             KeI386VirtualIntExtensions = TRUE;
  78         }
  79     }
  80
  81     /* Close the key */
  82     ZwClose(RegHandle);
  83 }
  84
  85 NTSTATUS
  86 NTAPI
  87 VdmpInitialize(PVOID ControlData)
  88 {
  89     OBJECT_ATTRIBUTES ObjectAttributes;
  90     UNICODE_STRING PhysMemName = RTL_CONSTANT_STRING(L"\\Device\\PhysicalMemory");
  91     NTSTATUS Status;
  92     HANDLE PhysMemHandle;
  93     PVOID BaseAddress;
  94     PVOID NullAddress = NULL;
  95     LARGE_INTEGER Offset;
  96     ULONG ViewSize;
  97
  98     /* Open the physical memory section */
  99     InitializeObjectAttributes(&ObjectAttributes,
 100                                &PhysMemName,
 101                                0,
 102                                NULL,
 103                                NULL);
 104     Status = ZwOpenSection(&PhysMemHandle,
 105                            SECTION_ALL_ACCESS,
 106                            &ObjectAttributes);
 107     if (!NT_SUCCESS(Status))
 108     {
 109         DPRINT1("Couldn't open \\Device\\PhysicalMemory\n");
 110         return Status;
 111     }
 112
 113     /* Map the BIOS and device registers into the address space */
 114     Offset.QuadPart = 0;
 115     ViewSize = PAGE_SIZE;
 116     BaseAddress = 0;
 117     Status = ZwMapViewOfSection(PhysMemHandle,
 118                                 NtCurrentProcess(),
 119                                 &BaseAddress,
 120                                 0,
 121                                 ViewSize,
 122                                 &Offset,
 123                                 &ViewSize,
 124                                 ViewUnmap,
 125                                 0,
 126                                 PAGE_READWRITE);
 127     if (!NT_SUCCESS(Status))
 128     {
 129         DPRINT1("Couldn't map physical memory (%x)\n", Status);
 130         ZwClose(PhysMemHandle);
 131         return Status;
 132     }
 133
 134     /* Enter SEH */
 135     _SEH2_TRY
 136     {
 137         /* Copy the first physical page into the first virtual page */
 138         RtlMoveMemory(NullAddress, BaseAddress, ViewSize);
 139     }
 140     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 141     {
 142         /* Fail */
 143         DPRINT1("Couldn't copy first page (%x)\n", Status);
 144         ZwClose(PhysMemHandle);
 145         ZwUnmapViewOfSection(NtCurrentProcess(), BaseAddress);
 146         _SEH2_YIELD(return _SEH2_GetExceptionCode());
 147     }
 148     _SEH2_END;
 149
 150     /* Close physical memory section handle */
 151     ZwClose(PhysMemHandle);
 152
 153     /* Unmap the section */
 154     Status = ZwUnmapViewOfSection(NtCurrentProcess(), BaseAddress);
 155
 156     if (!NT_SUCCESS(Status))
 157     {
 158         DPRINT1("Couldn't unmap the section (%x)\n", Status);
 159         return Status;
 160     }
 161
 162     return STATUS_SUCCESS;
 163 }
 164
 165 /* PUBLIC FUNCTIONS **********************************************************/
 166
 167 /*
 168  * @implemented
 169  */
 170 NTSTATUS
 171 NTAPI
 172 NtVdmControl(IN ULONG ControlCode,
 173              IN PVOID ControlData)
 174 {
 175     NTSTATUS Status;
 176     PAGED_CODE();
 177
 178     /* Check which control code this is */
 179     switch (ControlCode)
 180     {
 181         /* VDM Execution start */
 182         case VdmStartExecution:
 183
 184             /* Call the sub-function */
 185             Status = VdmpStartExecution();
 186             break;
 187
 188         case VdmInitialize:
 189
 190             /* Call the init sub-function */
 191             Status = VdmpInitialize(ControlData);
 192             break;
 193
 194         default:
 195
 196             /* Unsupported */
 197             DPRINT1("Unknown VDM call: %lx\n", ControlCode);
 198             Status = STATUS_INVALID_PARAMETER;
 199     }
 200
 201     /* Return the status */
 202     return Status;
 203 }