# A-profile CPU architecture support

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

- FEAT_AA32BF16 (AArch32 BFloat16 instructions)

- FEAT_AA32HPD (AArch32 hierarchical permission disables)

- FEAT_AA32I8MM (AArch32 Int8 matrix multiplication instructions)

- FEAT_AES (AESD and AESE instructions)

- FEAT_BBM at level 2 (Translation table break-before-make levels)

- FEAT_BF16 (AArch64 BFloat16 instructions)

- FEAT_BTI (Branch Target Identification)

- 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_CSV3 (Cache speculation variant 3)

- FEAT_DGH (Data gathering hint)

- FEAT_DIT (Data Independent Timing instructions)

- FEAT_DPB (DC CVAP instruction)

- FEAT_Debugv8p2 (Debug changes for v8.2)

- FEAT_Debugv8p4 (Debug changes for v8.4)

- FEAT_DotProd (Advanced SIMD dot product instructions)

- FEAT_DoubleFault (Double Fault Extension)

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

- FEAT_ETS (Enhanced Translation Synchronization)

- FEAT_FCMA (Floating-point complex number instructions)

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

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

- FEAT_FRINTTS (Floating-point to integer instructions)

- FEAT_FlagM (Flag manipulation instructions v2)

- FEAT_FlagM2 (Enhancements to flag manipulation instructions)

- FEAT_GTG (Guest translation granule size)

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

- FEAT_HCX (Support for the HCRX_EL2 register)

- FEAT_HPDS (Hierarchical permission disables)

- 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_LVA (Large Virtual Address space)

- FEAT_MTE (Memory Tagging Extension)

- FEAT_MTE2 (Memory Tagging Extension)

- FEAT_MTE3 (MTE Asymmetric Fault Handling)

- FEAT_PAN (Privileged access never)

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

- FEAT_PAuth (Pointer authentication)

- FEAT_PMULL (PMULL, PMULL2 instructions)

- 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_RNG (Random number generator)

- FEAT_S2FWB (Stage 2 forced Write-Back)

- FEAT_SB (Speculation Barrier)

- 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_SME_FA64 (Full A64 instruction set in Streaming SVE mode)

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

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

- FEAT_SPECRES (Speculation restriction instructions)

- FEAT_SSBS (Speculative Store Bypass Safe)

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

- SVE (The Scalable Vector Extension)

- SVE2 (The Scalable Vector Extension v2)

For information on the specifics of these extensions, please refer to the Armv8-A 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.) 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.