Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
23-20 Vol. 3
VM EXITS
For VM exits due to attempts to execute LLDT, LTR, SLDT, or STR, the field has
the format is given in Table 23-10.
29:28 Instruction identity:
0: SGDT
1: SIDT
2: LGDT
3: LIDT
31:30 Undefined.
Table 23-10. Format of the VM-Exit Instruction-Information Field as Used for LLDT,
LTR, SLDT, and STR
Bit Position(s) Content
1:0 Scaling:
0: no scaling
1: scale by 2
2: scale by 4
3: scale by 8 (used only on processors that support Intel 64 architecture)
Undefined for register instructions (bit 10 is set) and for memory instructions with
no index register (bit 10 is clear and bit 22 is set).
2Undefined.
6:3 Reg1:
0 = RAX
1= RCX
2= RDX
3= RBX
4= RSP
5= RBP
6= RSI
7= RDI
8–15 represent R8–R15, respectively (used only on processors that support
Intel 64 architecture)
Undefined for memory instructions (bit 10 is clear).
Table 23-9. Format of the VM-Exit Instruction-Information Field as Used for LIDT,
LGDT, SIDT, or SGDT (Contd.)
Bit Position(s) Content