Re: [PATCH v4 00/29] arm64: Permission Overlay Extension

[Joey Gouly <joey.gouly@arm.com>]

On Fri, May 03, 2024 at 02:01:18PM +0100, Joey Gouly wrote:
> Hi all,
> 
> This series implements the Permission Overlay Extension introduced in 2022
> VMSA enhancements [1]. It is based on v6.9-rc5.
> 
> One possible issue with this version, I took the last bit of HWCAP2.
> 
> Changes since v3[2]:
> 	- Moved Kconfig to nearer the end of the series
> 	- Reworked MMU Fault path, to check for POE faults earlier, under the mm lock
> 	- Rework VM_FLAGS to use Kconfig option
> 	- Don't check POR_EL0 in MTE sync tags function
> 	- Reworked KVM to fit into VNCR/VM configuration changes
> 	- Use new AT instruction in KVM
> 	- Rebase onto v6.9-rc5
> 
> The Permission Overlay Extension allows to constrain permissions on memory
> regions. This can be used from userspace (EL0) without a system call or TLB
> invalidation.
> 
> POE is used to implement the Memory Protection Keys [3] Linux syscall.
> 
> The first few patches add the basic framework, then the PKEYS interface is
> implemented, and then the selftests are made to work on arm64.
> 
> I have tested the modified protection_keys test on x86_64, but not PPC.
> I haven't build tested the x86/ppc arch changes.
> 
> Thanks,
> Joey

I found a silly off by one error, so I will be sending a v5 at some point.

> 
> Joey Gouly (29):
>   powerpc/mm: add ARCH_PKEY_BITS to Kconfig
>   x86/mm: add ARCH_PKEY_BITS to Kconfig
>   mm: use ARCH_PKEY_BITS to define VM_PKEY_BITN
>   arm64: disable trapping of POR_EL0 to EL2
>   arm64: cpufeature: add Permission Overlay Extension cpucap
>   arm64: context switch POR_EL0 register
>   KVM: arm64: Save/restore POE registers
>   KVM: arm64: make kvm_at() take an OP_AT_*
>   KVM: arm64: use `at s1e1a` for POE
>   arm64: enable the Permission Overlay Extension for EL0
>   arm64: re-order MTE VM_ flags
>   arm64: add POIndex defines
>   arm64: convert protection key into vm_flags and pgprot values
>   arm64: mask out POIndex when modifying a PTE
>   arm64: handle PKEY/POE faults
>   arm64: add pte_access_permitted_no_overlay()
>   arm64: implement PKEYS support
>   arm64: add POE signal support
>   arm64: enable PKEY support for CPUs with S1POE
>   arm64: enable POE and PIE to coexist
>   arm64/ptrace: add support for FEAT_POE
>   arm64: add Permission Overlay Extension Kconfig
>   kselftest/arm64: move get_header()
>   selftests: mm: move fpregs printing
>   selftests: mm: make protection_keys test work on arm64
>   kselftest/arm64: add HWCAP test for FEAT_S1POE
>   kselftest/arm64: parse POE_MAGIC in a signal frame
>   kselftest/arm64: Add test case for POR_EL0 signal frame records
>   KVM: selftests: get-reg-list: add Permission Overlay registers
> 
>  Documentation/arch/arm64/elf_hwcaps.rst       |   2 +
>  arch/arm64/Kconfig                            |  22 +++
>  arch/arm64/include/asm/cpufeature.h           |   6 +
>  arch/arm64/include/asm/el2_setup.h            |  10 +-
>  arch/arm64/include/asm/hwcap.h                |   1 +
>  arch/arm64/include/asm/kvm_asm.h              |   3 +-
>  arch/arm64/include/asm/kvm_host.h             |   4 +
>  arch/arm64/include/asm/mman.h                 |   8 +-
>  arch/arm64/include/asm/mmu.h                  |   1 +
>  arch/arm64/include/asm/mmu_context.h          |  51 ++++++-
>  arch/arm64/include/asm/pgtable-hwdef.h        |  10 ++
>  arch/arm64/include/asm/pgtable-prot.h         |   8 +-
>  arch/arm64/include/asm/pgtable.h              |  34 ++++-
>  arch/arm64/include/asm/pkeys.h                | 110 ++++++++++++++
>  arch/arm64/include/asm/por.h                  |  33 +++++
>  arch/arm64/include/asm/processor.h            |   1 +
>  arch/arm64/include/asm/sysreg.h               |   3 +
>  arch/arm64/include/asm/traps.h                |   1 +
>  arch/arm64/include/asm/vncr_mapping.h         |   1 +
>  arch/arm64/include/uapi/asm/hwcap.h           |   1 +
>  arch/arm64/include/uapi/asm/sigcontext.h      |   7 +
>  arch/arm64/kernel/cpufeature.c                |  23 +++
>  arch/arm64/kernel/cpuinfo.c                   |   1 +
>  arch/arm64/kernel/process.c                   |  28 ++++
>  arch/arm64/kernel/ptrace.c                    |  46 ++++++
>  arch/arm64/kernel/signal.c                    |  52 +++++++
>  arch/arm64/kernel/traps.c                     |  12 +-
>  arch/arm64/kvm/hyp/include/hyp/fault.h        |   5 +-
>  arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h    |  29 ++++
>  arch/arm64/kvm/sys_regs.c                     |   8 +-
>  arch/arm64/mm/fault.c                         |  56 ++++++-
>  arch/arm64/mm/mmap.c                          |   9 ++
>  arch/arm64/mm/mmu.c                           |  40 +++++
>  arch/arm64/tools/cpucaps                      |   1 +
>  arch/powerpc/Kconfig                          |   4 +
>  arch/x86/Kconfig                              |   4 +
>  fs/proc/task_mmu.c                            |   2 +
>  include/linux/mm.h                            |  20 ++-
>  include/uapi/linux/elf.h                      |   1 +
>  tools/testing/selftests/arm64/abi/hwcap.c     |  14 ++
>  .../testing/selftests/arm64/signal/.gitignore |   1 +
>  .../arm64/signal/testcases/poe_siginfo.c      |  86 +++++++++++
>  .../arm64/signal/testcases/testcases.c        |  27 +---
>  .../arm64/signal/testcases/testcases.h        |  28 +++-
>  .../selftests/kvm/aarch64/get-reg-list.c      |  14 ++
>  tools/testing/selftests/mm/Makefile           |   2 +-
>  tools/testing/selftests/mm/pkey-arm64.h       | 139 ++++++++++++++++++
>  tools/testing/selftests/mm/pkey-helpers.h     |   8 +
>  tools/testing/selftests/mm/pkey-powerpc.h     |   3 +
>  tools/testing/selftests/mm/pkey-x86.h         |   4 +
>  tools/testing/selftests/mm/protection_keys.c  | 109 ++++++++++++--
>  51 files changed, 1027 insertions(+), 66 deletions(-)
>  create mode 100644 arch/arm64/include/asm/pkeys.h
>  create mode 100644 arch/arm64/include/asm/por.h
>  create mode 100644 tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c
>  create mode 100644 tools/testing/selftests/mm/pkey-arm64.h
> 
> -- 
> 2.25.1
> 
> 
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