VPICD_Convert_Int_To_IRQ

include vpicd.inc

mov     ebx, VMHandle
mov     eax, VecNum
VxDcall VPICD_Convert_Int_To_IRQ
jc      not_mapped
mov     [IRQNum], eax
 

Retrieves the IRQ number (if any) corresponding to the specified interrupt vector number. Uses EAX and Flags.

• Returns the IRQ number in EAX and clears the carry flag if the interrupt vector number is mapped to an IRQ; otherwise sets carry flag.

VMHandle

Handle of VM for which to do the conversion.

VecNum

Interrupt vector number.

Since virtual machines can map IRQ numbers of the virtual PIC to any interrupt vector numbers, virtual devices should always explicitly check which interrupt vector is mapped to a particular IRQ.