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References: <20220930144758.30232-1-kirill.shutemov@linux.intel.com>
In-Reply-To: <20220930144758.30232-1-kirill.shutemov@linux.intel.com>
From:   Alexander Potapenko <glider@google.com>
Date:   Thu, 6 Oct 2022 15:58:21 +0200
Message-ID: <CAG_fn=X0xfY-5DS+YSpaLy8mHhAoJoceTq0vb2xmGBxB75wGMA@mail.gmail.com>
Subject: Re: [PATCHv9 00/14] Linear Address Masking enabling
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Kostya Serebryany <kcc@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Taras Madan <tarasmadan@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        "H . J . Lu" <hjl.tools@gmail.com>,
        Andi Kleen <ak@linux.intel.com>,
        Rick Edgecombe <rick.p.edgecombe@intel.com>,
        Bharata B Rao <bharata@amd.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Ashok Raj <ashok.raj@intel.com>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Sep 30, 2022 at 4:48 PM Kirill A. Shutemov
<kirill.shutemov@linux.intel.com> wrote:
>
> Linear Address Masking[1] (LAM) modifies the checking that is applied to
> 64-bit linear addresses, allowing software to use of the untranslated
> address bits for metadata.
>
> The capability can be used for efficient address sanitizers (ASAN)
> implementation and for optimizations in virtual machines.
>
> The patchset brings support for LAM for userspace addresses. Only LAM_U57=
 at
> this time.
>
> Please review and consider applying.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git lam

Not a big deal, but this tree contains LAM_U48 patches, and after
skipping those the SVM patch does not apply cleanly.

> v9:
>   - Fix race between LAM enabling and check that KVM memslot address does=
n't
>     have any tags;
>   - Reduce untagged_addr() overhead until the first LAM user;
>   - Clarify SVM vs. LAM semantics;
>   - Use mmap_lock to serialize LAM enabling;
> v8:
>   - Drop redundant smb_mb() in prctl_enable_tagged_addr();
>   - Cleanup code around build_cr3();
>   - Fix commit messages;
>   - Selftests updates;
>   - Acked/Reviewed/Tested-bys from Alexander and Peter;
> v7:
>   - Drop redundant smb_mb() in prctl_enable_tagged_addr();
>   - Cleanup code around build_cr3();
>   - Fix commit message;
>   - Fix indentation;
> v6:
>   - Rebased onto v6.0-rc1
>   - LAM_U48 excluded from the patchet. Still available in the git tree;
>   - add ARCH_GET_MAX_TAG_BITS;
>   - Fix build without CONFIG_DEBUG_VM;
>   - Update comments;
>   - Reviewed/Tested-by from Alexander;
> v5:
>   - Do not use switch_mm() in enable_lam_func()
>   - Use mb()/READ_ONCE() pair on LAM enabling;
>   - Add self-test by Weihong Zhang;
>   - Add comments;
> v4:
>   - Fix untagged_addr() for LAM_U48;
>   - Remove no-threads restriction on LAM enabling;
>   - Fix mm_struct access from /proc/$PID/arch_status
>   - Fix LAM handling in initialize_tlbstate_and_flush()
>   - Pack tlb_state better;
>   - Comments and commit messages;
> v3:
>   - Rebased onto v5.19-rc1
>   - Per-process enabling;
>   - API overhaul (again);
>   - Avoid branches and costly computations in the fast path;
>   - LAM_U48 is in optional patch.
> v2:
>   - Rebased onto v5.18-rc1
>   - New arch_prctl(2)-based API
>   - Expose status of LAM (or other thread features) in
>     /proc/$PID/arch_status
>
> [1] ISE, Chapter 10. https://cdrdv2.intel.com/v1/dl/getContent/671368
>
> Kirill A. Shutemov (10):
>   x86/mm: Fix CR3_ADDR_MASK
>   x86: CPUID and CR3/CR4 flags for Linear Address Masking
>   mm: Pass down mm_struct to untagged_addr()
>   x86/mm: Handle LAM on context switch
>   x86/uaccess: Provide untagged_addr() and remove tags before address
>     check
>   KVM: Serialize tagged address check against tagging enabling
>   x86/mm: Provide arch_prctl() interface for LAM
>   x86/mm: Reduce untagged_addr() overhead until the first LAM user
>   x86: Expose untagging mask in /proc/$PID/arch_status
>   x86/mm, iommu/sva: Make LAM and SVM mutually exclusive
>
> Weihong Zhang (4):
>   selftests/x86/lam: Add malloc and tag-bits test cases for
>     linear-address masking
>   selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address
>     masking
>   selftests/x86/lam: Add io_uring test cases for linear-address masking
>   selftests/x86/lam: Add inherit test cases for linear-address masking
>
>  arch/arm64/include/asm/memory.h               |   4 +-
>  arch/arm64/include/asm/signal.h               |   2 +-
>  arch/arm64/include/asm/uaccess.h              |   4 +-
>  arch/arm64/kernel/hw_breakpoint.c             |   2 +-
>  arch/arm64/kernel/traps.c                     |   4 +-
>  arch/arm64/mm/fault.c                         |  10 +-
>  arch/sparc/include/asm/pgtable_64.h           |   2 +-
>  arch/sparc/include/asm/uaccess_64.h           |   2 +
>  arch/x86/include/asm/cpufeatures.h            |   1 +
>  arch/x86/include/asm/mmu.h                    |  12 +-
>  arch/x86/include/asm/mmu_context.h            |  47 +
>  arch/x86/include/asm/processor-flags.h        |   4 +-
>  arch/x86/include/asm/tlbflush.h               |  35 +
>  arch/x86/include/asm/uaccess.h                |  46 +-
>  arch/x86/include/uapi/asm/prctl.h             |   5 +
>  arch/x86/include/uapi/asm/processor-flags.h   |   6 +
>  arch/x86/kernel/Makefile                      |   2 +
>  arch/x86/kernel/fpu/xstate.c                  |  47 -
>  arch/x86/kernel/proc.c                        |  60 ++
>  arch/x86/kernel/process.c                     |   3 +
>  arch/x86/kernel/process_64.c                  |  82 +-
>  arch/x86/mm/tlb.c                             |  48 +-
>  .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |   2 +-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |   2 +-
>  drivers/gpu/drm/radeon/radeon_gem.c           |   2 +-
>  drivers/infiniband/hw/mlx4/mr.c               |   2 +-
>  drivers/iommu/iommu-sva-lib.c                 |  12 +
>  drivers/media/common/videobuf2/frame_vector.c |   2 +-
>  drivers/media/v4l2-core/videobuf-dma-contig.c |   2 +-
>  .../staging/media/atomisp/pci/hmm/hmm_bo.c    |   2 +-
>  drivers/tee/tee_shm.c                         |   2 +-
>  drivers/vfio/vfio_iommu_type1.c               |   2 +-
>  fs/proc/task_mmu.c                            |   2 +-
>  include/linux/mm.h                            |  11 -
>  include/linux/mmu_context.h                   |   4 +
>  include/linux/uaccess.h                       |  15 +
>  lib/strncpy_from_user.c                       |   2 +-
>  lib/strnlen_user.c                            |   2 +-
>  mm/gup.c                                      |   6 +-
>  mm/madvise.c                                  |   2 +-
>  mm/mempolicy.c                                |   6 +-
>  mm/migrate.c                                  |   2 +-
>  mm/mincore.c                                  |   2 +-
>  mm/mlock.c                                    |   4 +-
>  mm/mmap.c                                     |   2 +-
>  mm/mprotect.c                                 |   2 +-
>  mm/mremap.c                                   |   2 +-
>  mm/msync.c                                    |   2 +-
>  tools/testing/selftests/x86/Makefile          |   2 +-
>  tools/testing/selftests/x86/lam.c             | 916 ++++++++++++++++++
>  virt/kvm/kvm_main.c                           |  14 +-
>  51 files changed, 1331 insertions(+), 125 deletions(-)
>  create mode 100644 arch/x86/kernel/proc.c
>  create mode 100644 tools/testing/selftests/x86/lam.c
>
> --
> 2.35.1
>


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Alexander Potapenko
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