41-6 Vol. 3D

SGX INSTRUCTION REFERENCES

THEN #GP(0); FI;

IF CR0.PG = 0

THEN #GP(0); FI;

(* DS must not be an expanded down segment *)
IF not in 64-bit mode and DS.Type is expand-down data

THEN #GP(0); FI;

Jump to leaf specific flow

Flags Affected

See individual leaf functions

Protected Mode Exceptions

#UD

If any of the LOCK/OSIZE/REP/VEX prefix is used.
If current privilege level is not 0.
If CPUID.(EAX=12H,ECX=0):EAX.SGX1 [bit 0] = 0.
If logical processor is in SMM.

#GP(0)

If IA32_FEATURE_CONTROL.LOCK = 0.
If IA32_FEATURE_CONTROL.SGX_ENABLE = 0.
If input value in EAX encodes an unsupported leaf.
If data segment expand down.
If CR0.PG=0.

Real-Address Mode Exceptions

#UD

ENCLS is not recognized in real mode.

Virtual-8086 Mode Exceptions

#UD

ENCLS is not recognized in virtual-8086 mode.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

#UD

If any of the LOCK/OSIZE/REP/VEX prefix is used.
If current privilege level is not 0.
If CPUID.(EAX=12H,ECX=0):EAX.SGX1 [bit 0] = 0.
If logical processor is in SMM.

#GP(0)

If IA32_FEATURE_CONTROL.LOCK = 0.
If IA32_FEATURE_CONTROL.SGX_ENABLE = 0.
If input value in EAX encodes an unsupported leaf.