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From:   Raghavendra Rao Ananta <rananta@google.com>
Date:   Wed, 5 Jul 2023 11:28:18 -0700
Message-ID: <CAJHc60xQtjvVsWRE=w-pAioNJW6uh-qKuZz2wp6bkT=X4oCm5A@mail.gmail.com>
Subject: Re: [RESEND PATCH v5 07/11] KVM: arm64: Define kvm_tlb_flush_vmid_range()
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>,
        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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On Tue, Jul 4, 2023 at 5:31=E2=80=AFPM Gavin Shan <gshan@redhat.com> wrote:
>
>
> On 6/22/23 03:49, Raghavendra Rao Ananta wrote:
> > Implement the helper kvm_tlb_flush_vmid_range() that acts
> > as a wrapper for range-based TLB invalidations. For the
> > given VMID, use the range-based TLBI instructions to do
> > the job or fallback to invalidating all the TLB entries.
> >
> > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> > ---
> >   arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
> >   arch/arm64/kvm/hyp/pgtable.c         | 20 ++++++++++++++++++++
> >   2 files changed, 30 insertions(+)
> >
>
> It may be reasonable to fold this to PATCH[08/11] since kvm_tlb_flush_vmi=
d_range() is
> only called by ARM64's kvm_arch_flush_remote_tlbs_range(), which is added=
 by PATCH[08/11].
> In either way, the changes look good to me:
>
Ah, the patches 10 and 11 also call kvm_tlb_flush_vmid_range(), so
probably it's better to keep the definition isolated?

Regards,
Raghavendra
> Reviewed-by: Gavin Shan <gshan@redhat.com>
>
> > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/=
asm/kvm_pgtable.h
> > index 4cd6762bda805..1b12295a83595 100644
> > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > @@ -682,4 +682,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(=
kvm_pte_t pte);
> >    *     kvm_pgtable_prot format.
> >    */
> >   enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
> > +
> > +/**
> > + * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entrie=
s
> > + *
> > + * @mmu:     Stage-2 KVM MMU struct
> > + * @addr:    The base Intermediate physical address from which to inva=
lidate
> > + * @size:    Size of the range from the base to invalidate
> > + */
> > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > +                             phys_addr_t addr, size_t size);
> >   #endif      /* __ARM64_KVM_PGTABLE_H__ */
> > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.=
c
> > index 3d61bd3e591d2..df8ac14d9d3d4 100644
> > --- a/arch/arm64/kvm/hyp/pgtable.c
> > +++ b/arch/arm64/kvm/hyp/pgtable.c
> > @@ -631,6 +631,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt=
)
> >       return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
> >   }
> >
> > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > +                             phys_addr_t addr, size_t size)
> > +{
> > +     unsigned long pages, inval_pages;
> > +
> > +     if (!system_supports_tlb_range()) {
> > +             kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
> > +             return;
> > +     }
> > +
> > +     pages =3D size >> PAGE_SHIFT;
> > +     while (pages > 0) {
> > +             inval_pages =3D min(pages, MAX_TLBI_RANGE_PAGES);
> > +             kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval=
_pages);
> > +
> > +             addr +=3D inval_pages << PAGE_SHIFT;
> > +             pages -=3D inval_pages;
> > +     }
> > +}
> > +
> >   #define KVM_S2_MEMATTR(pgt, attr) PAGE_S2_MEMATTR(attr, stage2_has_fw=
b(pgt))
> >
> >   static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgt=
able_prot prot,
>
> Thanks,
> Gavin
>