# A-profile CPU architecture support

QEMU’s TCG emulation includes support for the Armv5, Armv6, Armv7, Armv8 and Armv9 versions of the A-profile architecture. It also has support for the following architecture extensions:

- FEAT_AA32BF16 (AArch32 BFloat16 instructions)

- FEAT_AA32EL0 (Support for AArch32 at EL0)

- FEAT_AA32EL1 (Support for AArch32 at EL1)

- FEAT_AA32EL2 (Support for AArch32 at EL2)

- FEAT_AA32EL3 (Support for AArch32 at EL3)

- FEAT_AA32HPD (AArch32 hierarchical permission disables)

- FEAT_AA32I8MM (AArch32 Int8 matrix multiplication instructions)

- FEAT_AA64EL0 (Support for AArch64 at EL0)

- FEAT_AA64EL1 (Support for AArch64 at EL1)

- FEAT_AA64EL2 (Support for AArch64 at EL2)

- FEAT_AA64EL3 (Support for AArch64 at EL3)

- FEAT_AdvSIMD (Advanced SIMD Extension)

- FEAT_AES (AESD and AESE instructions)

- FEAT_AFP (Alternate floating-point behavior)

- FEAT_AIE (Memory Attribute Index Enhancement)

- FEAT_Armv9_Crypto (Armv9 Cryptographic Extension)

- FEAT_ASID16 (16 bit ASID)

- FEAT_ASID2 (Concurrent use of two ASIDs)

- FEAT_ATS1A (Address Translation operations that ignore stage 1 permissions)

- FEAT_BBML1 (Translation table break-before-make level 1)

- FEAT_BBML2 (Translation table break-before-make level 2)

- FEAT_BF16 (AArch64 BFloat16 instructions)

- FEAT_BTI (Branch Target Identification)

- FEAT_CCIDX (Extended cache index)

- FEAT_CHK (Check Feature Status)

- FEAT_CMOW (Control for cache maintenance permission)

- FEAT_CRC32 (CRC32 instructions)

- FEAT_Crypto (Cryptographic Extension)

- FEAT_CSSC (Common Short Sequence Compression instructions)

- FEAT_CSV2 (Cache speculation variant 2)

- FEAT_CSV2_1p1 (Cache speculation variant 2, version 1.1)

- FEAT_CSV2_1p2 (Cache speculation variant 2, version 1.2)

- FEAT_CSV2_2 (Cache speculation variant 2, version 2)

- FEAT_CSV2_3 (Cache speculation variant 2, version 3)

- FEAT_CSV3 (Cache speculation variant 3)

- FEAT_DGH (Data gathering hint)

- FEAT_DIT (Data Independent Timing instructions)

- FEAT_DoubleLock (Double Lock)

- FEAT_DPB (DC CVAP instruction)

- FEAT_DPB2 (DC CVADP instruction)

- FEAT_Debugv8p1 (Debug with VHE)

- FEAT_Debugv8p2 (Debug changes for v8.2)

- FEAT_Debugv8p4 (Debug changes for v8.4)

- FEAT_Debugv8p8 (Debug changes for v8.8)

- FEAT_DotProd (Advanced SIMD dot product instructions)

- FEAT_DoubleFault (Double Fault Extension)

- FEAT_E0PD (Preventing EL0 access to halves of address maps)

- FEAT_E2H0 (Programming of HCR_EL2.E2H)

- FEAT_EBF16 (AArch64 Extended BFloat16 instructions)

- FEAT_ECV (Enhanced Counter Virtualization)

- FEAT_EL0 (Support for execution at EL0)

- FEAT_EL1 (Support for execution at EL1)

- FEAT_EL2 (Support for execution at EL2)

- FEAT_EL3 (Support for execution at EL3)

- FEAT_EPAC (Enhanced pointer authentication)

- FEAT_ETS2 (Enhanced Translation Synchronization)

- FEAT_EVT (Enhanced Virtualization Traps)

- FEAT_F32MM (Single-precision Matrix Multiplication)

- FEAT_F64MM (Double-precision Matrix Multiplication)

- FEAT_FCMA (Floating-point complex number instructions)

- FEAT_FGT (Fine-Grained Traps)

- FEAT_FHM (Floating-point half-precision multiplication instructions)

- FEAT_FP (Floating Point extensions)

- FEAT_FP16 (Half-precision floating-point data processing)

- FEAT_FPAC (Faulting on AUT* instructions)

- FEAT_FPACCOMBINE (Faulting on combined pointer authentication instructions)

- FEAT_FPACC_SPEC (Speculative behavior of combined pointer authentication instructions)

- FEAT_FRINTTS (Floating-point to integer instructions)

- FEAT_FlagM (Flag manipulation instructions v2)

- FEAT_FlagM2 (Enhancements to flag manipulation instructions)

- FEAT_GCS (Guarded Control Stack Extension)

- FEAT_GTG (Guest translation granule size)

- FEAT_HAFDBS (Hardware management of the access flag and dirty bit state)

- FEAT_HBC (Hinted conditional branches)

- FEAT_HCX (Support for the HCRX_EL2 register)

- FEAT_HPDS (Hierarchical permission disables)

- FEAT_HPDS2 (Translation table page-based hardware attributes)

- FEAT_HPMN0 (Setting of MDCR_EL2.HPMN to zero)

- FEAT_I8MM (AArch64 Int8 matrix multiplication instructions)

- FEAT_IDST (ID space trap handling)

- FEAT_IESB (Implicit error synchronization event)

- FEAT_JSCVT (JavaScript conversion instructions)

- FEAT_LOR (Limited ordering regions)

- FEAT_LPA (Large Physical Address space)

- FEAT_LPA2 (Large Physical and virtual Address space v2)

- FEAT_LRCPC (Load-acquire RCpc instructions)

- FEAT_LRCPC2 (Load-acquire RCpc instructions v2)

- FEAT_LSE (Large System Extensions)

- FEAT_LSE2 (Large System Extensions v2)

- FEAT_LSE128 (128-bit Atomics)

- FEAT_LVA (Large Virtual Address space)

- FEAT_MEC (Memory Encryption Contexts)

  - This is a register-only implementation without encryption.

- FEAT_MixedEnd (Mixed-endian support)

- FEAT_MixedEndEL0 (Mixed-endian support at EL0)

- FEAT_MOPS (Standardization of memory operations)

- FEAT_MTE (Memory Tagging Extension)

- FEAT_MTE2 (Memory Tagging Extension)

- FEAT_MTE3 (MTE Asymmetric Fault Handling)

- FEAT_MTE_ASYM_FAULT (Memory tagging asymmetric faults)

- FEAT_MTE_ASYNC (Asynchronous reporting of Tag Check Fault)

- FEAT_NMI (Non-maskable Interrupt)

- FEAT_NV (Nested Virtualization)

- FEAT_NV2 (Enhanced nested virtualization support)

- FEAT_PACIMP (Pointer authentication - IMPLEMENTATION DEFINED algorithm)

- FEAT_PACQARMA3 (Pointer authentication - QARMA3 algorithm)

- FEAT_PACQARMA5 (Pointer authentication - QARMA5 algorithm)

- FEAT_PAN (Privileged access never)

- FEAT_PAN2 (AT S1E1R and AT S1E1W instruction variants affected by PSTATE.PAN)

- FEAT_PAN3 (Support for SCTLR_ELx.EPAN)

- FEAT_PAuth (Pointer authentication)

- FEAT_PAuth2 (Enhancements to pointer authentication)

- FEAT_PMULL (PMULL, PMULL2 instructions)

- FEAT_PMUv3 (PMU extension version 3)

- FEAT_PMUv3p1 (PMU Extensions v3.1)

- FEAT_PMUv3p4 (PMU Extensions v3.4)

- FEAT_PMUv3p5 (PMU Extensions v3.5)

- FEAT_RAS (Reliability, availability, and serviceability)

- FEAT_RASv1p1 (RAS Extension v1.1)

- FEAT_RDM (Advanced SIMD rounding double multiply accumulate instructions)

- FEAT_RME (Realm Management Extension) (NB: support status in QEMU is experimental)

- FEAT_RME_GPC2 (RME Granule Protection Check 2 Extension)

- FEAT_RNG (Random number generator)

- FEAT_RPRES (Increased precision of FRECPE and FRSQRTE)

- FEAT_S1PIE (Stage 1 permission indirections)

- FEAT_S2PIE (Stage 2 permission indirections)

- FEAT_S2FWB (Stage 2 forced Write-Back)

- FEAT_SB (Speculation Barrier)

- FEAT_SCTLR2 (Extension to SCTLR_ELx)

- FEAT_SEL2 (Secure EL2)

- FEAT_SHA1 (SHA1 instructions)

- FEAT_SHA256 (SHA256 instructions)

- FEAT_SHA3 (Advanced SIMD SHA3 instructions)

- FEAT_SHA512 (Advanced SIMD SHA512 instructions)

- FEAT_SM3 (Advanced SIMD SM3 instructions)

- FEAT_SM4 (Advanced SIMD SM4 instructions)

- FEAT_SME (Scalable Matrix Extension)

- FEAT_SME2 (Scalable Matrix Extension version 2)

- FEAT_SME2p1 (Scalable Matrix Extension version 2.1)

- FEAT_SME_B16B16 (Non-widening BFloat16 arithmetic for SME2)

- FEAT_SME_FA64 (Full A64 instruction set in Streaming SVE mode)

- FEAT_SME_F16F16 (Non-widening half-precision FP16 arithmetic for SME2)

- FEAT_SME_F64F64 (Double-precision floating-point outer product instructions)

- FEAT_SME_I16I64 (16-bit to 64-bit integer widening outer product instructions)

- FEAT_SVE (Scalable Vector Extension)

- FEAT_SVE_AES (Scalable Vector AES instructions)

- FEAT_SVE_B16B16 (Non-widening BFloat16 arithmetic for SVE2)

- FEAT_SVE_BitPerm (Scalable Vector Bit Permutes instructions)

- FEAT_SVE_PMULL128 (Scalable Vector PMULL instructions)

- FEAT_SVE_SHA3 (Scalable Vector SHA3 instructions)

- FEAT_SVE_SM4 (Scalable Vector SM4 instructions)

- FEAT_SVE2 (Scalable Vector Extension version 2)

- FEAT_SVE2p1 (Scalable Vector Extension version 2.1)

- FEAT_SPECRES (Speculation restriction instructions)

- FEAT_SSBS (Speculative Store Bypass Safe)

- FEAT_SSBS2 (MRS and MSR instructions for SSBS version 2)

- FEAT_TCR2 (Support for TCR2_ELx)

- FEAT_TGran16K (Support for 16KB memory translation granule size at stage 1)

- FEAT_TGran4K (Support for 4KB memory translation granule size at stage 1)

- FEAT_TGran64K (Support for 64KB memory translation granule size at stage 1)

- FEAT_TIDCP1 (EL0 use of IMPLEMENTATION DEFINED functionality)

- FEAT_TLBIOS (TLB invalidate instructions in Outer Shareable domain)

- FEAT_TLBIRANGE (TLB invalidate range instructions)

- FEAT_TTCNP (Translation table Common not private translations)

- FEAT_TTL (Translation Table Level)

- FEAT_TTST (Small translation tables)

- FEAT_UAO (Unprivileged Access Override control)

- FEAT_VHE (Virtualization Host Extensions)

- FEAT_VMID16 (16-bit VMID)

- FEAT_WFxT (WFE and WFI instructions with timeout)

- FEAT_XNX (Translation table stage 2 Unprivileged Execute-never)

- FEAT_XS (XS attribute)

For information on the specifics of these extensions, please refer to the Arm Architecture Reference Manual for A-profile architecture.

When a specific named CPU is being emulated, only those features which are present in hardware for that CPU are emulated. (If a feature is not in the list above then it is not supported, even if the real hardware should have it.) The `max` CPU enables all features.

# R-profile CPU architecture support

QEMU’s TCG emulation support for R-profile CPUs is currently limited. We emulate only the Cortex-R5 and Cortex-R5F CPUs.

# M-profile CPU architecture support

QEMU’s TCG emulation includes support for Armv6-M, Armv7-M, Armv8-M, and Armv8.1-M versions of the M-profile architucture. It also has support for the following architecture extensions:

- FP (Floating-point Extension)

- FPCXT (FPCXT access instructions)

- HP (Half-precision floating-point instructions)

- LOB (Low Overhead loops and Branch future)

- M (Main Extension)

- MPU (Memory Protection Unit Extension)

- PXN (Privileged Execute Never)

- RAS (Reliability, Serviceability and Availability): “minimum RAS Extension” only

- S (Security Extension)

- ST (System Timer Extension)

For information on the specifics of these extensions, please refer to the Armv8-M Arm Architecture Reference Manual.

When a specific named CPU is being emulated, only those features which are present in hardware for that CPU are emulated. (If a feature is not in the list above then it is not supported, even if the real hardware should have it.) There is no equivalent of the `max` CPU for M-profile.