|
include vmm.inc mov eax, Time ; number of milliseconds to time out mov edx, OFFSET32 RefData ; points to reference data mov esi, OFFSET32 TimeOutCallback ; points to callback procedure VMMcall Set_Global_Time_Out mov [TimeOut], esi ; time-out handle |
The Set_Global_Time_Out service schedules a time out to occur after the specified number of milliseconds have elapsed.
Time
Specifies the number of milliseconds to wait until calling the time-out callback procedure.
RefData
Points to reference data to be passed to the callback procedure.
TimeOutCallback
Points to the callback procedure. For more information about the callback procedure, see the following “Comments” section.
The ESI register contains the handle of the time out if the service is successful. Otherwise, the ESI is zero indicating that the time out is not scheduled.
The system calls the time-out callback procedure when the specified number of milliseconds elapse. The system calls the procedure as follows:
mov ebx, VM ; current VM handle
mov ecx, Extra ; number of milliseconds since time out
mov edx, OFFSET32 RefData ; points to reference data
mov ebp, OFFSET32 crs ; points to Client_Reg_Struc
call [TimeOutCallback]
The VM parameter is a handle specifying the current virtual machine. The RefData parameter points to the reference data for the callback procedure, and the crs parameter points to a Client_Reg_Struc structure that contains the register values for the current virtual machine.
The Extra parameter specifies the number of milliseconds that have elapsed since the actual time out occurred. Time outs are often delayed by 10 milliseconds or more, because the normal system timer runs at 20 milliseconds or slower.
If a virtual device needs more accurate time outs, it must increase the timer interrupt frequency using virtual timer device (VTD) services.
ESI, Flags