27-18 Vol. 3C

VM EXITS

6:3

Destination register:

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)

10:7

Undefined.

12:11

Operand size:

0: 16-bit

1: 32-bit

2: 64-bit

The value 3 is not used.

31:13

Undefined.

Table 27-13.  Format of the VM-Exit Instruction-Information Field as Used for VMCLEAR, VMPTRLD, VMPTRST, 

VMXON, XRSTORS, and XSAVES

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 instructions with no index register (bit 22 is set).

6:2

Undefined.

9:7

Address size:

0: 16-bit

1: 32-bit

2: 64-bit (used only on processors that support Intel 64 architecture)

Other values not used.

10

Cleared to 0.

14:11

Undefined.

17:15

Segment register:

0: ES

1: CS

2: SS

3: DS

4: FS

5: GS

Other values not used.

Table 27-12.  Format of the VM-Exit Instruction-Information Field as Used for RDRAND and RDSEED

Bit Position(s) Content