Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230808231330.3855936-1-rananta@google.com> <20230808231330.3855936-3-rananta@google.com>
 <c33b0518-6e64-7acf-efa8-f404fce1ccac@redhat.com>
In-Reply-To: <c33b0518-6e64-7acf-efa8-f404fce1ccac@redhat.com>
From:   Raghavendra Rao Ananta <rananta@google.com>
Date:   Wed, 9 Aug 2023 09:38:49 -0700
Message-ID: <CAJHc60yCJANBQOizaoSPhEJH9e8a9C6n68x4qdVkOhVZiiWqkw@mail.gmail.com>
Subject: Re: [PATCH v8 02/14] KVM: Declare kvm_arch_flush_remote_tlbs() globally
To:     Gavin Shan <gshan@redhat.com>
Cc:     Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.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>,
        Fuad Tabba <tabba@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
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi Gavin,

On Tue, Aug 8, 2023 at 9:00=E2=80=AFPM Gavin Shan <gshan@redhat.com> wrote:
>
>
> On 8/9/23 09:13, Raghavendra Rao Ananta wrote:
> > There's no reason for the architectures to declare
> > kvm_arch_flush_remote_tlbs() in their own headers. Hence to
> > avoid this duplication, make the declaration global, leaving
> > the architectures to define only __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS
> > as needed.
> >
> > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> > ---
> >   arch/mips/include/asm/kvm_host.h | 1 -
> >   include/linux/kvm_host.h         | 2 ++
> >   2 files changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/k=
vm_host.h
> > index 9b0ad8f3bf327..54a85f1d4f2c8 100644
> > --- a/arch/mips/include/asm/kvm_host.h
> > +++ b/arch/mips/include/asm/kvm_host.h
> > @@ -897,6 +897,5 @@ static inline void kvm_arch_vcpu_blocking(struct kv=
m_vcpu *vcpu) {}
> >   static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
> >
> >   #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS
> > -int kvm_arch_flush_remote_tlbs(struct kvm *kvm);
> >
> >   #endif /* __MIPS_KVM_HOST_H__ */
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index e3f968b38ae97..ade5d4500c2ce 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -1484,6 +1484,8 @@ static inline int kvm_arch_flush_remote_tlbs(stru=
ct kvm *kvm)
> >   {
> >       return -ENOTSUPP;
> >   }
> > +#else
> > +int kvm_arch_flush_remote_tlbs(struct kvm *kvm);
> >   #endif
> >
> >   #ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA
>
> Is the declaration inconsistent to that in arch/x86/include/asm/kvm_host.=
h?
> In order to keep them consistent, I guess we need move kvm_arch_flush_rem=
ote_tlbs()
> from x86's header file to arch/x86/kvm/mmu/mmu.c and 'inline' needs to be=
 dropped.
>
Unsure of the original intentions, I didn't want to disturb any
existing arrangements. If more people agree to this refactoring, I'm
happy to move.

Thank you.
Raghavendra
> Thanks,
> Gavin
>