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Date:   Fri, 21 Jul 2023 16:31:06 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Alistair Popple <apopple@nvidia.com>
Cc:     akpm@linux-foundation.org, ajd@linux.ibm.com,
        catalin.marinas@arm.com, fbarrat@linux.ibm.com,
        iommu@lists.linux.dev, jhubbard@nvidia.com, kevin.tian@intel.com,
        kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au,
        nicolinc@nvidia.com, npiggin@gmail.com, robin.murphy@arm.com,
        seanjc@google.com, will@kernel.org, x86@kernel.org,
        zhi.wang.linux@gmail.com, sj@kernel.org
Subject: Re: [PATCH v3 5/5] mmu_notifiers: Rename invalidate_range notifier
Message-ID: <ZLrc+vEQcCEpI0wd@ziepe.ca>
References: <cover.b24362332ec6099bc8db4e8e06a67545c653291d.1689842332.git-series.apopple@nvidia.com>
 <3cbd2a644d56d503b47cfc35868d547f924f880e.1689842332.git-series.apopple@nvidia.com>
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On Thu, Jul 20, 2023 at 06:39:27PM +1000, Alistair Popple wrote:
> There are two main use cases for mmu notifiers. One is by KVM which
> uses mmu_notifier_invalidate_range_start()/end() to manage a software
> TLB.
> 
> The other is to manage hardware TLBs which need to use the
> invalidate_range() callback because HW can establish new TLB entries
> at any time. Hence using start/end() can lead to memory corruption as
> these callbacks happen too soon/late during page unmap.
> 
> mmu notifier users should therefore either use the start()/end()
> callbacks or the invalidate_range() callbacks. To make this usage
> clearer rename the invalidate_range() callback to
> arch_invalidate_secondary_tlbs() and update documention.
> 
> Signed-off-by: Alistair Popple <apopple@nvidia.com>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  arch/arm64/include/asm/tlbflush.h               |  6 +-
>  arch/powerpc/mm/book3s64/radix_hugetlbpage.c    |  2 +-
>  arch/powerpc/mm/book3s64/radix_tlb.c            | 10 ++--
>  arch/x86/include/asm/tlbflush.h                 |  2 +-
>  arch/x86/mm/tlb.c                               |  2 +-
>  drivers/iommu/amd/iommu_v2.c                    | 10 ++--
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 13 ++---
>  drivers/iommu/intel/svm.c                       |  8 +--
>  drivers/misc/ocxl/link.c                        |  8 +--
>  include/linux/mmu_notifier.h                    | 48 +++++++++---------
>  mm/huge_memory.c                                |  4 +-
>  mm/hugetlb.c                                    |  7 +--
>  mm/mmu_notifier.c                               | 20 ++++++--
>  13 files changed, 76 insertions(+), 64 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason