MPAM0_EL1 MPAM0 Register (EL1) when FEAT_MPAM is implemented Holds information to generate MPAM labels for memory requests when executing at EL0. MPAM If FEAT_MPAM is implemented, EL2 is implemented and enabled in the current Security state, and the MPAM virtualization option is present, then: If MPAMHCR_EL2.GSTAPP_PLK == 1 and the Effective value of HCR_EL2.TGE is 0, MPAM1_EL1 is used instead of MPAM0_EL1 to generate MPAM information to label memory requests. If the Effective value of HCR_EL2.{E2H, TGE} is not {1, 1} and MPAMHCR_EL2.EL0_VPMEN == 1, then MPAM PARTIDs in MPAM0_EL1 are virtual and mapped into physical PARTIDs for the current Security state. MPAM0_EL1 is a 64-bit register. 63 48 63:48 Reserved, RES0. PMG_D 47 40 47:40 Performance monitoring group property for PARTID_D. AU PMG_I 39 32 39:32 Performance monitoring group property for PARTID_I. AU PARTID_D 31 16 31:16 Partition ID for data accesses, including load and store accesses, made from EL0. AU PARTID_I 15 0 15:0 Partition ID for instruction accesses made from EL0. AU None of the fields in this register are permitted to be cached in a TLB. MRS <Xt>, MPAM0_EL1 if !IsFeatureImplemented(FEAT_MPAM) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then Undefined(); elsif HaveEL(EL3) && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif EL2Enabled() && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM2_EL2().TRAPMPAM0EL1 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else X{64}(t) = MPAM0_EL1(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then Undefined(); elsif HaveEL(EL3) && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = MPAM0_EL1(); end; elsif PSTATE.EL == EL3 then X{64}(t) = MPAM0_EL1(); end; MSR MPAM0_EL1, <Xt> if !IsFeatureImplemented(FEAT_MPAM) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then Undefined(); elsif HaveEL(EL3) && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif EL2Enabled() && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM2_EL2().TRAPMPAM0EL1 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else MPAM0_EL1() = X{64}(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then Undefined(); elsif HaveEL(EL3) && (IsFeatureImplemented(FEAT_MPAMv0p1) || IsFeatureImplemented(FEAT_MPAMv1p0)) && MPAM3_EL3().TRAPLOWER == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else MPAM0_EL1() = X{64}(t); end; elsif PSTATE.EL == EL3 then MPAM0_EL1() = X{64}(t); end; 2026-03-26 20:27:25 2026-03_rel