kernel/arch/arm64/tools/gen-sysreg.awk, branch master

arm64/sysreg: Move generation of RES0/RES1/UNKN to function

2025-11-13T18:09:46Z

The RESx and UNKN define generation happens in two places (EndSysreg and EndSysregFields), and was using nearly identical code. Split this out into a function, and call that instead, rather then keeping the dupliated code. There are no changes to the generated sysregs as part of this change. Signed-off-by: Sascha Bischoff Signed-off-by: Catalin Marinas

arm64/sysreg: Support feature-specific fields with 'Prefix' descriptor

2025-11-13T18:09:46Z

Some system register field encodings change based on, for example the in-use architecture features, or the context in which they are accessed. In order to support these different field encodings, introduce the Prefix descriptor (Prefix, EndPrefix) for describing such sysregs. The Prefix descriptor can be used in the following way: Sysreg EXAMPLE 0 1 2 3 4 Prefix FEAT_A Field 63:0 Foo EndPrefix Prefix FEAT_B Field 63:1 Bar Res0 0 EndPrefix Field 63:0 Baz EndSysreg This will generate a single set of system register encodings (REG_, SYS_, ...), and then generate three sets of field definitions for the system register called EXAMPLE. The first set is prefixed by FEAT_A, e.g. FEAT_A_EXAMPLE_Foo. The second set is prefixed by FEAT_B, e.g., FEAT_B_EXAMPLE_Bar. The third set is not given a prefix at all, e.g. EXAMPLE_BAZ. For each set, a corresponding set of defines for Res0, Res1, and Unkn is generated. The intent for the final prefix-less fields is to describe default or legacy field encodings. This ensure that prefixed encodings can be added to already-present sysregs without affecting existing legacy code. Prefixed fields must be defined before those without a prefix, and this is checked by the generator. This ensures consisnt ordering within the sysregs definitions. The Prefix descriptor can be used within Sysreg or SysregFields blocks. Field, Res0, Res1, Unkn, Rax, SignedEnum, Enum can all be used within a Prefix block. Fields and Mapping can not. Fields that vary with features must be described as part of a SysregFields block, instead. Mappings, which are just a code comment, make little sense in this context, and have hence not been included. There are no changes to the generated system register definitions as part of this change. Signed-off-by: Sascha Bischoff Reviewed-by: Mark Brown Signed-off-by: Catalin Marinas

arm64/sysreg: Fix checks for incomplete sysreg definitions

2025-11-13T18:09:46Z

The checks for incomplete sysreg definitions were checking if the next_bit was greater than 0, which is incorrect and missed occasions where bit 0 hasn't been defined for a sysreg. The reason is that next_bit is -1 when all bits have been processed (LSB - 1). Change the checks to use >= 0, instead. Also, set next_bit in Mapping to -1 instead of 0 to match these new checks. There are no changes to the generated sysreg definitons as part of this change, and conveniently no definitions lack definitions for bit 0. Signed-off-by: Sascha Bischoff Reviewed-by: Mark Brown Signed-off-by: Catalin Marinas

arm64: sysreg: Add validation checks to sysreg header generation script

2025-09-11T13:46:07Z

The gen_sysreg.awk script processes the system register specification in the sysreg text file to generate C macro definitions. The current script will silently accept certain errors in the specification file, leading to incorrect header generation. For example, a Sysreg or SysregFields can be accidentally duplicated, causing its macros to be emitted twice. An Enum can contain duplicate values for different items, which is architecturally incorrect. Add checks to catch these errors at build time. The script now tracks all seen Sysreg and SysregFields definitions and checks for duplicates. It also tracks values within each Enum block to ensure entries are unique. Acked-by: Marc Zyngier Signed-off-by: Fuad Tabba Acked-by: Mark Rutland Signed-off-by: Will Deacon

arm64/sysreg: Enforce whole word match for open/close tokens

2025-03-14T17:54:44Z

Opening and closing tokens can also match on words with common prefixes like "Endsysreg" vs "EndsysregFields". This could potentially make the script go wrong in weird ways so make it fall through to the fatal unhandled statement catcher if it doesn't fully match the current block. Closing ones also get expect_fields(1) to ensure nothing other than whitespace follows. Signed-off-by: James Clark Acked-by: Will Deacon Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20250115162600.2153226-3-james.clark@linaro.org Signed-off-by: Catalin Marinas

arm64/sysreg: Allow a 'Mapping' descriptor for system registers

2024-12-19T18:00:58Z

*EL02 and *_EL12 system registers are actually only accessors for EL0 and EL1 registers accessed from EL2 when HCR_EL2.E2H==1. They do not have fields of their own. To that effect, introduce a 'Mapping' entry, describing which system register an _EL12 register maps to. Implementation wise, this is handled the same was as Fields, which ls only a comment. Acked-by: Mark Rutland Reviewed-by: Mark Brown Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20241219173351.1123087-2-maz@kernel.org Signed-off-by: Will Deacon

arm64/sysreg: allow *Enum blocks in SysregFields blocks

2023-04-06T14:28:54Z

We'd like to support Enum/SignedEnum/UnsignedEnum blocks within SysregFields blocks, so that we can define enumerations for sets of registers. This isn't currently supported by gen-sysreg.awk due to the way we track the active block, which can't handle more than a single layer of nesting, which imposes an awkward requirement that when ending a block we know what the parent block is when calling change_block() Make this nicer by using a stack of active blocks, with block_push() to start a block, and block_pop() to end a block. Doing so means that we only need to check the active block at the start of parsing a line: for the start of a block we can check the parent is valid, and for the end of a block we check that the active block is valid. This structure makes the block parsing simpler and makes it easy to permit a block to live under several potential parents (e.g. by permitting Enum to start when the active block is Sysreg or SysregFields). It also permits further nesting, if we need that in future. To aid debugging, the stack of active blocks is reported for fatal errors, and an error is raised if the file is terminated without ending the active block. For clarity I've renamed the top-level element from "None" to "Root". The Fields element it intended only for use within Sysreg blocks, and does not make sense within SysregFields blocks, and so remains forbidden within a SysregFields block. I've verified using sha1sum that this patch does not change the current generated contents of . Signed-off-by: Mark Rutland Cc: Anshuman Khandual Cc: Catalin Marinas Cc: Marc Zyngier Cc: Mark Brown Cc: Will Deacon Reviewed-by: Anshuman Khandual Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20230306114836.2575432-1-mark.rutland@arm.com Signed-off-by: Will Deacon

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2023-02-25T19:30:21Z

Pull kvm updates from Paolo Bonzini: "ARM: - Provide a virtual cache topology to the guest to avoid inconsistencies with migration on heterogenous systems. Non secure software has no practical need to traverse the caches by set/way in the first place - Add support for taking stage-2 access faults in parallel. This was an accidental omission in the original parallel faults implementation, but should provide a marginal improvement to machines w/o FEAT_HAFDBS (such as hardware from the fruit company) - A preamble to adding support for nested virtualization to KVM, including vEL2 register state, rudimentary nested exception handling and masking unsupported features for nested guests - Fixes to the PSCI relay that avoid an unexpected host SVE trap when resuming a CPU when running pKVM - VGIC maintenance interrupt support for the AIC - Improvements to the arch timer emulation, primarily aimed at reducing the trap overhead of running nested - Add CONFIG_USERFAULTFD to the KVM selftests config fragment in the interest of CI systems - Avoid VM-wide stop-the-world operations when a vCPU accesses its own redistributor - Serialize when toggling CPACR_EL1.SMEN to avoid unexpected exceptions in the host - Aesthetic and comment/kerneldoc fixes - Drop the vestiges of the old Columbia mailing list and add [Oliver] as co-maintainer RISC-V: - Fix wrong usage of PGDIR_SIZE instead of PUD_SIZE - Correctly place the guest in S-mode after redirecting a trap to the guest - Redirect illegal instruction traps to guest - SBI PMU support for guest s390: - Sort out confusion between virtual and physical addresses, which currently are the same on s390 - A new ioctl that performs cmpxchg on guest memory - A few fixes x86: - Change tdp_mmu to a read-only parameter - Separate TDP and shadow MMU page fault paths - Enable Hyper-V invariant TSC control - Fix a variety of APICv and AVIC bugs, some of them real-world, some of them affecting architecurally legal but unlikely to happen in practice - Mark APIC timer as expired if its in one-shot mode and the count underflows while the vCPU task was being migrated - Advertise support for Intel's new fast REP string features - Fix a double-shootdown issue in the emergency reboot code - Ensure GIF=1 and disable SVM during an emergency reboot, i.e. give SVM similar treatment to VMX - Update Xen's TSC info CPUID sub-leaves as appropriate - Add support for Hyper-V's extended hypercalls, where "support" at this point is just forwarding the hypercalls to userspace - Clean up the kvm->lock vs. kvm->srcu sequences when updating the PMU and MSR filters - One-off fixes and cleanups - Fix and cleanup the range-based TLB flushing code, used when KVM is running on Hyper-V - Add support for filtering PMU events using a mask. If userspace wants to restrict heavily what events the guest can use, it can now do so without needing an absurd number of filter entries - Clean up KVM's handling of "PMU MSRs to save", especially when vPMU support is disabled - Add PEBS support for Intel Sapphire Rapids - Fix a mostly benign overflow bug in SEV's send|receive_update_data() - Move several SVM-specific flags into vcpu_svm x86 Intel: - Handle NMI VM-Exits before leaving the noinstr region - A few trivial cleanups in the VM-Enter flows - Stop enabling VMFUNC for L1 purely to document that KVM doesn't support EPTP switching (or any other VM function) for L1 - Fix a crash when using eVMCS's enlighted MSR bitmaps Generic: - Clean up the hardware enable and initialization flow, which was scattered around multiple arch-specific hooks. Instead, just let the arch code call into generic code. Both x86 and ARM should benefit from not having to fight common KVM code's notion of how to do initialization - Account allocations in generic kvm_arch_alloc_vm() - Fix a memory leak if coalesced MMIO unregistration fails selftests: - On x86, cache the CPU vendor (AMD vs. Intel) and use the info to emit the correct hypercall instruction instead of relying on KVM to patch in VMMCALL - Use TAP interface for kvm_binary_stats_test and tsc_msrs_test" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (325 commits) KVM: SVM: hyper-v: placate modpost section mismatch error KVM: x86/mmu: Make tdp_mmu_allowed static KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes KVM: arm64: nv: Filter out unsupported features from ID regs KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 KVM: arm64: nv: Allow a sysreg to be hidden from userspace only KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2 KVM: arm64: nv: Handle SMCs taken from virtual EL2 KVM: arm64: nv: Handle trapped ERET from virtual EL2 KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 KVM: arm64: nv: Support virtual EL2 exceptions KVM: arm64: nv: Handle HCR_EL2.NV system register traps KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state KVM: arm64: nv: Add EL2 system registers to vcpu context KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set KVM: arm64: nv: Introduce nested virtualization VCPU feature KVM: arm64: Use the S2 MMU context to iterate over S2 table ...

arm64/sysreg: Allow enumerations to be declared as signed or unsigned

2023-02-01T17:51:19Z

Many of our enumerations follow a standard scheme where the values can be treated as signed however there are some where the value must be treated as signed and others that are simple enumerations where there is no clear ordering to the values. Provide new field types SignedEnum and UnsignedEnum which allows the signedness to be specified in the sysreg definition and emit a REG_FIELD_SIGNED define for these which is a boolean corresponding to our current FTR_UNSIGNED and FTR_SIGNED macros. Existing Enums will need to be converted, since these do not have a define generated anyone wishing to use the sign of one of these will need to explicitly annotate that field so nothing should start going wrong by default. Acked-by: Mark Rutland Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221207-arm64-sysreg-helpers-v4-1-25b6b3fb9d18@kernel.org Signed-off-by: Catalin Marinas

arm64: Allow the definition of UNKNOWN system register fields

2023-01-12T21:07:43Z

The CCSIDR_EL1 register contains an UNKNOWN field (which replaces fields that were actually defined in previous revisions of the architecture). Define an 'Unkn' field type modeled after the Res0/Res1 types to allow such description. This allows the generation of #define CCSIDR_EL1_UNKN (UL(0) | GENMASK_ULL(31, 28)) which may have its use one day. Hopefully the architecture doesn't add too many of those in the future. Signed-off-by: Marc Zyngier Signed-off-by: Akihiko Odaki Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20230112023852.42012-2-akihiko.odaki@daynix.com Signed-off-by: Oliver Upton