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From:   Raghavendra Rao Ananta <rananta@google.com>
Date:   Wed, 2 Aug 2023 16:28:52 -0700
Message-ID: <CAJHc60xAUVt5fbhEkOqeC-VF8SWVOt3si=1yxVVAUW=+Hu_wNg@mail.gmail.com>
Subject: Re: [PATCH v7 02/12] KVM: arm64: Use kvm_arch_flush_remote_tlbs()
To:     Marc Zyngier <maz@kernel.org>
Cc:     Sean Christopherson <seanjc@google.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Zenghui Yu <yuzenghui@huawei.com>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        Jing Zhang <jingzhangos@google.com>,
        Reiji Watanabe <reijiw@google.com>,
        Colton Lewis <coltonlewis@google.com>,
        David Matlack <dmatlack@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
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Sure, I'll change it to kvm_arch_flush_vm_tlbs() in v8.

Thanks,
Raghavendra

On Wed, Aug 2, 2023 at 8:55=E2=80=AFAM Marc Zyngier <maz@kernel.org> wrote:
>
> On Mon, 31 Jul 2023 22:50:07 +0100,
> Sean Christopherson <seanjc@google.com> wrote:
> >
> > On Thu, Jul 27, 2023, Marc Zyngier wrote:
> > > On Sat, 22 Jul 2023 03:22:41 +0100,
> > > Raghavendra Rao Ananta <rananta@google.com> wrote:
> > > >
> > > > Stop depending on CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL and opt to
> > > > standardize on kvm_arch_flush_remote_tlbs() since it avoids
> > > > duplicating the generic TLB stats across architectures that impleme=
nt
> > > > their own remote TLB flush.
> > > >
> > > > This adds an extra function call to the ARM64 kvm_flush_remote_tlbs=
()
> > > > path, but that is a small cost in comparison to flushing remote TLB=
s.
> > >
> > > Well, there is no such thing as a "remote TLB" anyway. We either have
> > > a non-shareable or inner-shareable invalidation. The notion of remote
> > > would imply that we track who potentially has a TLB, which we
> > > obviously don't.
> >
> > Maybe kvm_arch_flush_vm_tlbs()?  The "remote" part is misleading even o=
n x86 when
> > running on Hyper-V, as the flush may be done via a single hypercall and=
 by kicking
> > "remote" vCPUs.
>
> Yup, this would be much better.
>
> Thanks,
>
>         M.
>
> --
> Without deviation from the norm, progress is not possible.