struct AMD64_DBGKD_CONTROL_SET

typedef struct _AMD64_DBGKD_CONTROL_SET
{
     ULONG TraceFlag;
     UINT64 Dr7;
     UINT64 CurrentSymbolStart;
     UINT64 CurrentSymbolEnd;
} AMD64_DBGKD_CONTROL_SET, *PAMD64_DBGKD_CONTROL_SET;

Windows Vista Kernel Structures