This series enables support for the data processing extensions in the newly released 2023 architecture, this is mainly support for 8 bit floating point formats. Most of the extensions only introduce new instructions and therefore only require hwcaps but there is a new EL0 visible control register FPMR used to control the 8 bit floating point formats, we need to manage traps for this and context switch it.
Due to uncertainty with the plan for parsing ID registers to identify which features to expose to the guest the KVM support is placed at the end of the series, it will need to be revised once that issue is resolved. The sharing of floating point save code between the host and guest kernels slightly complicates the introduction of KVM support, we first introduce host support with some placeholders for KVM then replace those with the actual KVM support.
I've not added test coverage for ptrace, I've got a test program which exercises all the FP ptrace interfaces and their interactions together, my plan is to cover it there rather than add another tiny test program that duplicates the boilerplace for tracing a target and doesn't actually run the traced program.
Signed-off-by: Mark Brown broonie@kernel.org --- Changes in v4: - Rebase onto v6.8-rc1. - Move KVM support to the end of the series. - Link to v3: https://lore.kernel.org/r/20231205-arm64-2023-dpisa-v3-0-dbcbcd867a7f@kernel...
Changes in v3: - Rebase onto v6.7-rc3. - Hook up traps for FPMR in emulate-nested.c. - Link to v2: https://lore.kernel.org/r/20231114-arm64-2023-dpisa-v2-0-47251894f6a8@kernel...
Changes in v2: - Rebase onto v6.7-rc1. - Link to v1: https://lore.kernel.org/r/20231026-arm64-2023-dpisa-v1-0-8470dd989bb2@kernel...
--- Mark Brown (14): arm64/cpufeature: Hook new identification registers up to cpufeature arm64/fpsimd: Enable host kernel access to FPMR arm64/fpsimd: Support FEAT_FPMR arm64/signal: Add FPMR signal handling arm64/ptrace: Expose FPMR via ptrace arm64/hwcap: Define hwcaps for 2023 DPISA features kselftest/arm64: Handle FPMR context in generic signal frame parser kselftest/arm64: Add basic FPMR test kselftest/arm64: Add 2023 DPISA hwcap test coverage KVM: arm64: Share all userspace hardened thread data with the hypervisor KVM: arm64: Add newly allocated ID registers to register descriptions KVM: arm64: Support FEAT_FPMR for guests KVM: arm64: selftests: Document feature registers added in 2023 extensions KVM: arm64: selftests: Teach get-reg-list about FPMR
Documentation/arch/arm64/elf_hwcaps.rst | 49 +++++ arch/arm64/include/asm/cpu.h | 3 + arch/arm64/include/asm/cpufeature.h | 5 + arch/arm64/include/asm/fpsimd.h | 2 + arch/arm64/include/asm/hwcap.h | 15 ++ arch/arm64/include/asm/kvm_arm.h | 4 +- arch/arm64/include/asm/kvm_host.h | 5 +- arch/arm64/include/asm/processor.h | 6 +- arch/arm64/include/uapi/asm/hwcap.h | 15 ++ arch/arm64/include/uapi/asm/sigcontext.h | 8 + arch/arm64/kernel/cpufeature.c | 72 +++++++ arch/arm64/kernel/cpuinfo.c | 18 ++ arch/arm64/kernel/fpsimd.c | 13 ++ arch/arm64/kernel/ptrace.c | 42 ++++ arch/arm64/kernel/signal.c | 59 ++++++ arch/arm64/kvm/emulate-nested.c | 8 + arch/arm64/kvm/fpsimd.c | 14 +- arch/arm64/kvm/hyp/include/hyp/switch.h | 9 +- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 4 +- arch/arm64/kvm/sys_regs.c | 17 +- arch/arm64/tools/cpucaps | 1 + include/uapi/linux/elf.h | 1 + tools/testing/selftests/arm64/abi/hwcap.c | 217 +++++++++++++++++++++ tools/testing/selftests/arm64/signal/.gitignore | 1 + .../arm64/signal/testcases/fpmr_siginfo.c | 82 ++++++++ .../selftests/arm64/signal/testcases/testcases.c | 8 + .../selftests/arm64/signal/testcases/testcases.h | 1 + tools/testing/selftests/kvm/aarch64/get-reg-list.c | 11 +- 28 files changed, 670 insertions(+), 20 deletions(-) --- base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d change-id: 20231003-arm64-2023-dpisa-2f3d25746474
Best regards,