[v4,00/14] arm64: Support for 2023 DPISA extensions

Message

Mark Brown Jan. 22, 2024, 4:28 p.m. UTC

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 <[e-mail]>
---
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/[e-mail]

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/[e-mail]

Changes in v2:
- Rebase onto v6.7-rc1.
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
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,