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From:   Raghavendra Rao Ananta <rananta@google.com>
Date:   Thu, 13 Jul 2023 11:47:19 -0700
Message-ID: <CAJHc60y6AaAUVy=V6GHTpVhHGO3Bjn1vpTnYpdFiFLjS-vR-uA@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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Hi Gavin,

On Wed, Jul 5, 2023 at 5:04=E2=80=AFPM Gavin Shan <gshan@redhat.com> wrote:
>
> On 7/6/23 04:28, Raghavendra Rao Ananta wrote:
> > On Tue, Jul 4, 2023 at 5:31=E2=80=AFPM Gavin Shan <gshan@redhat.com> wr=
ote:
> >> 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_=
vmid_range() is
> >> only called by ARM64's kvm_arch_flush_remote_tlbs_range(), which is ad=
ded 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?
> >
>
> Thanks for your explanation. It's fine to have two separate patches in th=
is
> case. I still need to spend some time to look at PATCH[11/11] whose subje=
ct
> includes typo (intructions -> instructions)
>
I'm planning to send v6 soon, but I'm happy to wait if you have any
other comments on v5 patch-11.
Appreciate your help with the reviews.

Thank you.
Raghavendra
> Thanks,
> Gavin
>
> >> Reviewed-by: Gavin Shan <gshan@redhat.com>
> >>
> >>> diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/includ=
e/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_pro=
t(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 entr=
ies
> >>> + *
> >>> + * @mmu:     Stage-2 KVM MMU struct
> >>> + * @addr:    The base Intermediate physical address from which to in=
validate
> >>> + * @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/pgtabl=
e.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 *p=
gt)
> >>>        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, inv=
al_pages);
> >>> +
> >>> +             addr +=3D inval_pages << PAGE_SHIFT;
> >>> +             pages -=3D inval_pages;
> >>> +     }
> >>> +}
> >>> +
> >>>    #define KVM_S2_MEMATTR(pgt, attr) PAGE_S2_MEMATTR(attr, stage2_has=
_fwb(pgt))
> >>>
> >>>    static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_=
pgtable_prot prot,
>