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include vpicd.inc
 
clc
cmp     [TimeOut],0
jz      no_timeout
stc                         ; carry set if interrupt timed-out
 
no_timeout:
mov     eax, IRQHand        ; IRQ handle
mov     ebx, VM             ; current VM handle
call    VID_IRET_Proc
 
The VID_IRET_Proc procedure handles attempts by a virtual machine to return
from an interrupt. The system calls this procedure whenever a virtual
machine executes an iret instruction or whenever a time-out occurs for a
simulated interrupt.
 
The system disables interrupts before calling this procedure. The procedure
can re-enable interrupts if necessary.
 
Parameter  Description
────────────────────────────────────────────────────────────────────────────
 
IRQHand    Specifies the handle identifying the interrupt request.
 
VM         Specifies the handle identifying the current virtual machine.
 
Return Value
 
This procedure has no return value.
 
Comments
 
This procedure is useful for devices that must simulate large numbers of
interrupts in a short period of time. For example, the virtual COM device
simulates an interrupt, allows one character to be read from the COM port,
and waits for the virtual machine to execute an iret instruction before
putting more data into the virtual COM receive buffer.
 
This procedure may modify EAX, EBX, ECX, EDX, ESI, and Flags.
 
See Also
 
VPICD_IRQ_Descriptor
 
 
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