MPAM3_EL3 MPAM3 Register (EL3) when FEAT_MPAM is implemented MPAM2_EL2 Architectural AArch64 63 63 63 63 63 63 63 63 when (FEAT_MPAMv0p1 is implemented or FEAT_MPAMv1p0 is implemented) and EL2 is implemented MPAM1_EL1 Architectural AArch64 63 63 63 63 63 63 63 63 when FEAT_MPAMv0p1 is implemented or FEAT_MPAMv1p0 is implemented Holds information to generate MPAM labels for memory requests when executing at EL3. MPAM MPAM3_EL3 is a 64-bit register. MPAMEN 63 63 63 MPAM Enable. MPAM is enabled when MPAMEN == 1. When disabled, all PARTIDs and PMGs are output as their default value in the corresponding ID space. Values of this field are: 0b0 The default PARTID and default PMG are output in MPAM information when executing at any ELn. 0b1 MPAM information is output based on the MPAMn_ELx register for ELn according the MPAM configuration. '0' RW TRAPLOWER 62 62 62 Trap direct accesses to MPAM System registers that are not UNDEFINED from all ELn lower than EL3. This trap is higher priority than any of the traps controlled by MPAM _EL2 registers. 0b0 Do not force trapping of direct accesses of MPAM System registers to EL3. 0b1 Force direct accesses of MPAM System registers to trap to EL3. '1' SDEFLT 61 61 0 SDEFLT overrides the PARTID and PMG with the default PARTID and default PMG when executing in the Secure state. 0b0 The PARTID and PMG are determined normally in the Secure state. 0b1 When executing in the Secure state, the PARTID is always PARTID 0, and the PMG is always PMG 0. AU When (FEAT_MPAMv0p1 is implemented or FEAT_MPAMv1p1 is implemented) and MPAMIDR_EL1.HAS_SDEFLT == '1' 61 61 61 Reserved, RES0. Otherwise FORCE_NS 60 60 0 FORCE_NS forces MPAM_NS to always be 1 in the Secure state. An implementation is permitted to have this field as RAO if the implementation does not support generating MPAM_NS as 0. 0b0 MPAM_NS is 0 when executing in the Secure state. 0b1 MPAM_NS is 1 when executing in the Secure state. AU When FEAT_MPAMv0p1 is implemented and MPAMIDR_EL1.HAS_FORCE_NS == '1' 60 60 60 Reserved, RES0. Otherwise 59 58 59:58 Reserved, RES0. ALTSP_HEN 57 57 0 Hierarchical enable for alternative PARTID space controls. Alternative PARTID space controls in MPAM2_EL2 have no effect when this field is zero. For more information, see 'In a PE with FEAT_RME, selection of primary or alternative PARTID space'. 0b0 Disable alternative PARTID space controls in MPAM2_EL2. The PARTID space for PARTIDs in MPAM2_EL2, MPAM1_EL1, and MPAM0_EL1 is selected by MPAM3_EL3.ALTSP_HFC. 0b1 Enable alternative PARTID space controls in MPAM2_EL2 to control the PARTID space used for PARTIDs in MPAM2_EL2, MPAM1_EL1, and MPAM0_EL1. AU When FEAT_RME is implemented and MPAMIDR_EL1.HAS_ALTSP == '1' 57 57 57 Reserved, RES0. Otherwise ALTSP_HFC 56 56 0 Hierarchical force of alternative PARTID space controls. When MPAM3_EL3.ALTSP_HEN is 0, the PARTID space for PARTIDs in MPAM2_EL2, MPAM1_EL1, and MPAM0_EL1 is selected by the value of this bit. For more information, see 'In a PE with FEAT_RME, selection of primary or alternative PARTID space'. 0b0 When MPAM3_EL3.ALTSP_HEN is 0, the PARTID space of MPAM2_EL2.PARTID, MPAM1_EL1.PARTID and MPAM0_EL1.PARTID are the primary PARTID space for the security state. 0b1 When MPAM3_EL3.ALTSP_HEN is 0, the PARTID space of MPAM2_EL2.PARTID and MPAM1_EL1.PARTID and MPAM0_EL1.PARTID are the alternative PARTID space for the security state. AU When FEAT_RME is implemented and MPAMIDR_EL1.HAS_ALTSP == '1' 56 56 56 Reserved, RES0. Otherwise ALTSP_EL3 55 55 0 Select alternative PARTID space for PARTIDs in MPAM3_EL3. For more information, see 'In a PE with FEAT_RME, selection of primary or alternative PARTID space'. 0b0 Selects the primary PARTID space of MPAM3_EL3.PARTID_I and MPAM3_EL3.PARTID_D. 0b1 Selects the alternative PARTID space of MPAM3_EL3.PARTID_I and MPAM3_EL3.PARTID_D. ID When FEAT_RME is implemented and MPAMIDR_EL1.HAS_ALTSP == '1' 55 55 55 Reserved, RES0. Otherwise 54 53 54:53 Reserved, RES0. RT_ALTSP_NS 52 52 0 Selects whether the alternative PARTID space for the Root security state is the Secure PARTID space or the Non-secure PARTID space. MPAM3_EL3.RT_ALTSP_NS selects the alternative PARTID space for the Root Security state when MPAM3_EL3.ALTSP_EL3 == 1. This field has no effect except in the Root security state (EL3). 0b0 The alternative PARTID space in the Root security state is the Secure PARTID space. 0b1 The alternative PARTID space in the Root security state is the Non-secure PARTID space. ID When FEAT_RME is implemented and MPAMIDR_EL1.HAS_ALTSP == '1' 52 52 52 Reserved, RES0. Otherwise 51 48 51:48 Reserved, RES0. PMG_D 47 40 47:40 Performance monitoring group for data accesses. AU PMG_I 39 32 39:32 Performance monitoring group for instruction accesses. AU PARTID_D 31 16 31:16 Partition ID for data accesses, including load and store accesses, made from EL3. AU PARTID_I 15 0 15:0 Partition ID for instruction accesses made from EL3. AU None of the fields in this register are permitted to be cached in a TLB. MRS <Xt>, MPAM3_EL3 if !IsFeatureImplemented(FEAT_MPAM) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then Undefined(); elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then X{64}(t) = MPAM3_EL3(); end; MSR MPAM3_EL3, <Xt> if !IsFeatureImplemented(FEAT_MPAM) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then Undefined(); elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then if IsFeatureImplemented(FEAT_FGWTE3) && FGWTE3_EL3().MPAM3_EL3 == '1' then AArch64_SystemAccessTrap(EL3, 0x18); else MPAM3_EL3() = X{64}(t); end; end; 2026-03-26 20:27:25 2026-03_rel