Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1525

INTn/INTO/INT3—Call to Interrupt Procedure (Continued)
FI;
IF instruction pointer is not within code segment limits THEN #GP(0); FI;
IF CR4.VME = 0
THEN
ELSE (*VME = 1*)
Permission*)
FI;
END;
VM86_INTERRUPT_TO_PRIV0:
tempEFLAGS  EFLAGS;
VM  0;
Volume 4: Base IA-32 Instruction Reference
OR 18 bytes (no error code pushed);
THEN #SS(segment selector + EXT);
FI;
IF IOPL=3
THEN
IF Gate DPL = 3
THEN (*CPL=3, VM=1, IOPL=3, VME=0, gate DPL=3)
IF Target CPL != 0
THEN #GP(0);
ELSE Goto VM86_INTERURPT_TO_PRIV0;
FI;
ELSE (*Gate DPL < 3*)
#GP(0);
FI;
ELSE (*IOPL < 3*)
#GP(0);
FI;
(*Check whether interrupt is directed for INT n instruction only,
(*executes virtual 8086 interupt, protected mode interrupt or faults*)
Ptr <- [TSS + 66];
IF BIT[Ptr-32,N] = 0
THEN (*Interrupt redirected*)
Goto VM86_INTERRUPT_TO_VM86;
ELSE
IF IOPL = 3
THEN
IF Gate DPL = 3
THEN
IF Target CPL != 0
THEN #GP(0);
ELSE Goto VM86_INTERRUPT_TO_PRIV0;
FI;
ELSE #GP(0);
FI;
ELSE (*IOPL < 3*)
#GP(0);
FI;
FI;
(*Fetch IO permission bitmpa pointer*)
(*software redirection bitmap is 32 bytes below IO
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