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From:   Yu Zhao <yuzhao@google.com>
Date:   Mon, 31 Jul 2023 14:35:29 -0600
Message-ID: <CAOUHufaK1zibYzOxUGWgYatLnts+fOG6X8fBAwtGA_S6cdDxMw@mail.gmail.com>
Subject: Re: [PATCH] KVM: Wrap kvm_{gfn,hva}_range.pte in a per-action union
To:     Sean Christopherson <seanjc@google.com>
Cc:     Marc Zyngier <maz@kernel.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        Huacai Chen <chenhuacai@kernel.org>,
        Anup Patel <anup@brainfault.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Paolo Bonzini <pbonzini@redhat.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-mips@vger.kernel.org, kvm@vger.kernel.org,
        kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org
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On Fri, Jul 28, 2023 at 6:41=E2=80=AFPM Sean Christopherson <seanjc@google.=
com> wrote:
>
> Wrap kvm_{gfn,hva}_range.pte in a union so that future notifier events ca=
n
> pass event specific information up and down the stack without needing to
> constantly expand and churn the APIs.  Lockless aging of SPTEs will pass
> around a bitmap, and support for memory attributes will pass around the
> new attributes for the range.
>
> Add a "KVM_NO_ARG" placeholder to simplify handling events without an
> argument (creating a dummy union variable is midly annoying).
>
> Opportunstically drop explicit zero-initialization of the "pte" field, as
> omitting the field (now a union) has the same effect.
>
> Cc: Yu Zhao <yuzhao@google.com>
> Link: https://lore.kernel.org/all/CAOUHufagkd2Jk3_HrVoFFptRXM=3DhX2CV8f+M=
-dka-hJU4bP8kw@mail.gmail.com
> Signed-off-by: Sean Christopherson <seanjc@google.com>

Acked-by: Yu Zhao <yuzhao@google.com>