40-6 Vol. 3D
ENCLAVE EXITING EVENTS
(* Restore the FS and GS *)
FS.selector CR_SAVE_FS.selector;
FS.base CR_SAVE_FS.base;
FS.limit CR_SAVE_FS.limit;
FS.access_rights CR_SAVE_FS.access_rights;
GS.selector CR_SAVE_GS.selector;
GS.base CR_SAVE_GS.base;
GS.limit CR_SAVE_GS.limit;
GS.access_rights CR_SAVE_GS.access_rights;
(* Examine exception code and update enclave internal states*)
exception_code Exception or interrupt vector;
(* Indicate the exit reason in SSA *)
IF (exception_code = (#DE OR #DB OR #BP OR #BR OR #UD OR #MF OR #AC OR #XM ))
THEN
CR_GPR_PA.EXITINFO.VECTOR exception_code;
IF (exception code = #BP)
THEN CR_GPR_PA.EXITINFO.EXIT_TYPE 6;
ELSE CR_GPR_PA.EXITINFO.EXIT_TYPE 3;
FI;
CR_GPR_PA.EXITINFO.VALID 1;
ELSE IF (exception_code is #PF or #GP )
THEN
(* Check SECS.MISCSELECT using CR_ACTIVE_SECS *)
IF (SECS.MISCSELECT[0] is set)
THEN
CR_GPR_PA.EXITINFO.VECTOR exception_code;
CR_GPR_PA.EXITINFO.EXIT_TYPE 3;
IF (exception_code is #PF)
THEN
SSA.MISC.EXINFO. MADDR CR2;
SSA.MISC.EXINFO.ERRCD PFEC;
SSA.MISC.EXINFO.RESERVED 0;
ELSE
SSA.MISC.EXINFO. MADDR 0;
SSA.MISC.EXINFO.ERRCD GPEC;
SSA.MISC.EXINFO.RESERVED 0;
FI;
CR_GPR_PA.EXITINFO.VALID 1;
FI;
ELSE
CR_GPR_PA.EXITINFO.VECTOR 0;
CR_GPR_PA.EXITINFO.EXIT_TYPE 0
CR_GPR_PA.REASON.VALID 0;
FI;
(* Execution will resume at the AEP *)
RIP CR_TCS_PA.AEP;
(* Set EAX to the ERESUME leaf index *)
EAX 3;