V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

VIF
       Virtual Interrupt Flag (Intel, CPU)


The Free On-line Dictionary of Computing (30 December 2018):

VIF

   VHDL Interface Format.  Intermediate language used by the
   Vantage VHDL compiler.  "A VHDL Compiler Based on Attribute
   Grammar Methodology", R. Farrow et al, SIGPLAN NOtices
   24(7):120-130 (Jul 1989).